Symposium Organizers
Wenzhuo Wu, Purdue University
Christian Falconi, University of Tor Vergata
Rusen Yang, University of Minnesota
Junyi Zhai, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences
ES4.3: Piezoelectric Nanogenerators I
Session Chairs
Christian Falconi
Rusen Yang
Tuesday AM, April 18, 2017
PCC North, 200 Level, Room 229 A
11:30 AM - *ES4.3.01
Ferroelectric Polymer for Energy Harvesting and Self-Powered Devices/Sensors
Pooi See Lee 1 , Kaushik Parida 1 , Venkatswarlu Bhavanasi 1
1 School of Materials Science and Engineering, Nanyang Technological University, Singapore Singapore
Show AbstractMechanical/vibrational energy harvesting has drawn interests in recent years because of its potential in energy generation and self-powered sensors/ devices. The mechanical energy can be harvested efficiently by using piezoelectric and triboelectric mechanisms. Poly (vinylidene difluoride-trifluoroethylene) [PVDF-TrFE] is a functional polymer with ferroelectric, piezoelectric and triboelectric behavior. Piezoelectric polymers typically sustains higher strains and strain rates compared to its inorganic counterparts making it suitable for the mechanical energy harvesting. Yet the piezoelectric energy harvesting ability of PVDF-TrFE is lower because of its lower piezoelectric coefficient and Young’s modulus. In this talk, I will discuss various approaches taken to improve the energy harvesting ability of PVDF-TrFE polymer such as improving the piezoelectric coefficients, compressibility and incoporation of electrostatic effects. 1-D nanostructuring leads to the improved piezoelectric coefficients of PVDF-TrFE (44 pm/V, two times higher than the films) and hence an improved mechanical energy harvesting properties. Porous PVDF-TrFE films can be fabricated to improve the compressibility of the PVDF-TrFE and therefore the energy harvesting ability. Furthermore, we utilized these porous piezoelectric films to realize fast charging self-powered supercapacitor, with 90% of its charging potential achieved in less than 10 sec. We have found that bi-layer film based on PVDF-TrFE and graphene oxide leads to both enhanced piezoelectric and electrostatic effects, while elevating the Young’s modulus and creating a residual stress (or stress gradient) in the films, leading to the improved energy harvesting performance.
In addition to the piezoelectric phenomenon, PVDF-TrFE is utilized for triboelectric energy harvesting by utilizing its functional properties. By tuning the polarization, we realized a good triboelectric transparent negative material. A wide range self-powered pressure sensor and an energy harvester utilizing triboelectric phenomenon can be built based on PVDF-TrFE. The efforts illustrated lead to the pathways of realizing futuristic self-powered devices and sensors in addition to clean energy generation.
12:00 PM - ES4.3.02
Smart Fibers for Textile-Based Micro-Generators and Compliant Energy Storage
Xin Lu 1 , Hang Qu 1 , Maksim Skorobogatiy 1
1 , Ecole Polytechnique de Montreal, Montreal, Quebec, Canada
Show AbstractIn the past decade, the R&D of micro-generators based on flexible piezoelectric fibers has received intensive attention due to the boosting market of personal wearable electronics. In previous works, piezoelectric fibers are normally fabricated by two routes. In the first one, ceramic piezoelectric materials such as ZnO Nanowires (NWs) or BaTiO3 NWs are directly deposited or wet-extruded along a metallic wire/filament. While the fabrication process is simple, the as-fabricated fibers normally have reliability issues, as the bonding between the ceramic materials and the metallic core is weak, especially when the fibers are subject to repeated bending or stretching actions. The second route is based on traditional polymer wet-spinning or melt-spinning techniques in which piezoelectric polymers such as PVDF or PVDF-TrFE are extruded together with a conductive polymer to form a sheath-core fiber structure. Note that the as-spun fibers may require an additional deposition of a metallic layer as an outer electrode that may also have reliability problems due to surface abrasion and frequent bending actions.
In this abstract, we report fabrication of the multimaterial piezoelectric fibers from perovskite ceramic nanoparticles (BTO/PZT)-PVDF, and CNT-PVDF composites via fiber drawing. Furthermore, we perform a comparative study of the piezoelectric performance of thus fabricated fibers. The proposed fibers feature a spiral geometry that significantly increases the fiber piezoelectric response. Due to the judicious arrangement of the conductive layers, connecting to our fibers is easy as the two electrodes occupy the opposite sides of the exposed fiber surface. Experimentally, a piezoelectric generator using a 10 cm long BTO-PVDF (BTO concentration: 20 wt%) fiber could generate an open-circuit voltage of 1.4 V and a short-circuit current of 0.8 nA respectively, when the fiber tip is displaced transversely by 10 mm. The corresponding voltage and current were ~6 V and ~4 nA for a PZT-PVDF (20 wt% PZT) fiber generator, and ~3 V and ~1.2 nA for a CNT-PVDF (0.4 wt% CNT) fiber generator. Compared to the previous piezoelectric fibers, our fibers adopt a spiral structure, and thus have much larger active areas for piezoelectricity generation as well as smaller gaps between the electrodes. As a result, our fibers could generate much higher piezoelectric currents, which are proportional to the number of turns in a spiral. Among other advantages of the piezoelectric fibers reported in this paper are low cost of the materials used in fabrication, light weight, good durability, and possibility of mass production via fiber drawing.As examples of practical applications of the proposed piezoelectric fibers, we present energy harvesting textiles using BTO-PVDF fibers, and characterized their performance in the context of wearable and automotive microgenerators. Moreover, we also present detection of sound using CNT-PVDF fiber that feature piezoelectric voltage generated by sound wave to be proportional to the square root of the acoustic power.
Reference X. Lu, H. Qu and M. Skorobogatiy.“Piezoelectric Microstructured Fibers Fabricated from Thermoplastic Nanocomposites using Fiber Drawing Technique-Comparative Study and Potential Applications”, ACS Nano, in Press (2017).
12:15 PM - *ES4.3.03
Polymer-Based Nanogenerators for Piezoelectric and Triboelectric Energy Harvesting Applications
Sohini Kar-Narayan 1
1 , University of Cambridge, Cambridge United Kingdom
Show AbstractHarvesting energy from ambient mechanical sources in our environment has generated tremendous interest as it offers a fundamental energy solution for ‘small power’ applications, including but not limited to wireless sensors. In this context, piezoelectric and/or triboelectric materials offer the simplest means of directly converting mechanical vibrations, from sources such as moving parts of machines, fluid flow and even body movements, into electrical power for microscale device applications. In particular, nanoscale energy harvesters, or nanogenerators, are capable of converting low-level ambient vibrations into electrical energy, thus paving the way for the realisation of the next generation of self-powered devices. Polymer-based nanogenerators are attractive as they are inherently flexible and robust making them less prone to mechanical failure which is a key requirement for vibrational energy harvesters. They are also lightweight, easy and cheap to fabricate, lead free and biocompatible, but their energy harvesting performance is often found lacking in comparison to more commonly studied inorganic materials. Our group thus develops scalable nanofabrication techniques for flexible and low-cost polymer-based nanogenerators with improved energy conversion efficiency, by using facile template-assisted nanowire growth techniques. In this talk, I will discuss our recent advances in incorporating nanowires of P(VDF-TrFE), Nylon-11, cellulose and poly-lactic acid into scalable piezoelectric and triboelectric nanogenerators, as well as the design and performance of polymer-ceramic nanocomposite nanogenerators. I will also focus on advanced scanning probe microscopy methods that we use for the characterization of these polymeric nanomaterials and the extraction of relevant materials properties for nanogenerator design.
12:45 PM - ES4.3.04
Machine-Washable Textile Triboelectric Nanogenerators for Effective Human Respiratory Monitoring through Loom Weaving of Metallic Yarns
Zhizhen Zhao 1 , Casey Yan 2 , Youfan Hu 1 , Zijian Zheng 2
1 , Peking University, Peking China, 2 , The Hong Kong Polytechnic University, Hong Kong Hong Kong
Show AbstractWith rapid growth in performance and materials of nanogenerators, comfortable and convenient energy harvesting along with useful self-powered sensing become close to our daily life. In the meanwhile, wearable technology has attracted huge attention because it satisfies both human body information collecting and comfortable clothing. Recently, textile triboelectric nanogenerators (t-TENGs) become very popular due to their ease of fabrication and promising output performance. Weaving special yarns into soft fabric makes t-TENGs lightweight, portable and flexible. Still, the bulky fabric structures, washing durability and scalability with the conventional textile manufacturing industry are critical challenges hampering further technological advances of t-TENGs. Now, a big breakthrough takes place in t-TENG which is fabricated by direct weaving of Cu-coated polyethylene terephthalate (Cu-PET) warp yarns and polyimide coated Cu-PET (PI-Cu-PET) weft yarns on an industrial sample weaving loom. The new device takes fully the advantage of the woven structure itself. Upon even very subtle deformation, such as tapping and bending, the contact area of the crisscross intersections of the weft and warp yarns changes which lead to effective generation of triboelectric charges. Electric output of voltage or current will be generated under such process. And we integrate the as-made t-TENG into a chest strap to monitor human respiratory information including rate and depth. More importantly, the as-made t-TENG can withstand the industry standard machine-wash tests, showing remarkable washing durability. It is worth noting that all the materials used here have been widely accepted by the textile industry, and the device fabrication is done with miniaturized industrial machineries, making the t-TENGs fully compatible with high-throughput textile processing. In a word, the textile industry compatibility, the proven machine wash ability, and the sensitivity to subtle human body motions make the new designed t-TENG a very promising candidate for wearable technology with excellent scalability, and can be further applied in sports, healthcare sectors and many other fields.
ES4.4: Triboelectric Nanogenerators II
Session Chairs
Tuesday PM, April 18, 2017
PCC North, 200 Level, Room 229 A
2:30 PM - *ES4.4.01
Boosted Output Performance of Triboelectric Nanogenerator via Electric Double Layer Effect
Jeong Min Baik 1
1 , Ulsan National Institute of Science and Technology, Ulsan Korea (the Republic of)
Show AbstractFor existing triboelectric nanogenerators, it is important to explore unique methods to further enhance the electric output power under realistic environments in order to speed up its commercialization. We report here, for the first time, a new practical TENG composed of three layers, in which the key layer, an electric double layer, is inserted between a top layer, made of Al/PDMS, and a bottom layer, made of Al, respectively. The efficient charge separation in the middle layer, based on Volta’s electrophorus, is resulted from sequential contact configuration of the TENG and direct electrical connection of the middle layer to the earth (ground). This device design provides substantially larger electric potential at even low frequency regime than in previous reports. A sustainable and enhanced output performance of 1.22 mA and 46.8 mW/cm2 under low frequency of 3 Hz is produced, giving over 16-fold enhancement in output power and corresponding to energy conversion efficiency of 22.4 %. Through the integration of the TENG with a signal-processing circuit, wireless sensors such as a remote controller and an infrared sensor are demonstrated. Finally, a portable power-supplying system, which provides enough DC power for charging a battery of smart watch/phone, were also successfully developed.
3:15 PM - *ES4.4.03
Triboelectric Nanogenerator for Energy Harvesting and Self-Powered Biomechanical Motion Sensors
Qingliang Liao 1 , Fang Yi 1 , Yue Zhang 1
1 , University of Science and Technology Beijing, Beijing China
Show AbstractThe advances in industry and information technology promote the development of internet of things and sensor technology. Consequently, there is a growing need to develop power sources for sensor works that currently may include thousands or even millions of sensor nodes with various functionalities. Self-powered sensors based on energy harvesting technologies have been given significant attention with the increasing concern over energy crisis, which generally realized through two approaches: one is to drive conventional sensors by energy harvesters; the other one is to detect signals via the electrical outputs triggered by ambient environment stimulations. Triboelectric nanogenerator (TENG) is a new technology to harvest mechanical energy and has attracted attentive attention. TENGs can be utilized as self-powered sensors and have the advantages of light weight, low cost, and high sensitivity.
In this work, we introduce three kinds of TENGs to act as self-powered biomechanical motion sensors. Three kinds of TENGs with different structures were designed and the detecting properties of the fabricated biomechanical motion sensors were measured. The working mechanisms of the TENGs were investigated.
A single-electrode-mode triboelectric nanogenerator is developed to accurately detect the trajectory, displacement, velocity and acceleration of moving objects in two dimensions, which is applied to visualize the movement of a sliding object and walking steps of a person. A triboelectric nanogenerator based on a unique working principle that the changes of triboelectric charge distribution/density on the triboelectric layer inducing the polarization of charges is developed, which can serve as self-powered wearable sensors to detect diaphragm breathing and joint motion. A triboelectric nanogenerator with self-recovering characteristics is developed, which can act as self-powered sensors to detect humidity, airflow rate, force and be applied for security monitoring.
The designed three kinds of biomechanical motion sensor show excellent responsive properties. These works not only provide new design options for energy harvesters but also offer new perspectives for self-powered sensors.
3:45 PM - ES4.4.04
Tribotronics—A New Field by Coupling Triboelectricity and Semiconductor
Chi Zhang 1 , Yaokun Pang 1 , Zhong Lin Wang 1
1 , Chinese Academy of Sciences, Beijing China
Show AbstractRecently, the invention of the triboelectric nanogenerator (TENG) has provided an effective approach to convert ambient mechanical energy into electricity, which has great application in micro-energy, macro-energy, and active sensors. On the other hand, the triboelectric induced potential difference is an inner electrical signal created by the external mechanical force, which could be used as a gate signal to tune/control the carrier transport characteristics in field effect transistor as the same effect as applying a gate voltage. In 2014, by coupling triboelectricity and semiconductor, tribotronics as a new field is proposed, which is about the devices fabricated using the electrostatic potential created by triboelectrification as a “gate” voltage to tune/control electrical transport and transformation in semiconductors.
In the past years, various tribotronic functional devices have been experimentally demonstrated. The tribotronic logic device has established the relationship between the mechanical force and CMOS logic electric level and universal combinational logic circuits have been demonstrated for first performing mechanical-electrical coupled tribotronic logic operations. The flexible organic tribotronic memory has demonstrated an active memory which can be written and erased by externally applied touch actions. The organic and MoS2 tribotronic transistors have extended the tribotronics to the organic and 2D materials, respectively, and exhibited the material variety for the interactive application. By further introducing optoelectronics, a new field of tribo-phototronics has been consequently derived by three way coupling among triboelectricity, semiconductor, and photoexcitation. The tribotronic light-emitting diode and phototransistor have been developed for demonstrating the triboelectric charges enhanced light-emission and photoelectric conversion characteristics, respectively.
Tribotronics has established a direct interaction mechanism between the external environment and electronics, which is likely to have important applications in sensors, human silicon technology interfacing, MEMS, nanorobotics, and active flexible electronics. As an extension of the proposed piezoelectric nanogenerator in 2006, piezotronics in 2007 and triboelectric nanogenerator in 2012, tribotronics is another original and novel field in the development of nano-energy and nano-electronics. The concepts and results presented in this review show promises for implementing novel micro/nano-electromechanical devices that may derive plenty of potentially important research interests and applications in sensing, energy harvesting, human-machine interfacing, MEMS/NEMS and active flexible/stretchable electronics in the near future.
ES4.5: Piezophototronics I
Session Chairs
Tuesday PM, April 18, 2017
PCC North, 200 Level, Room 229 A
4:30 PM - *ES4.5.01
Piezotronics-Regulated Electrochemical and Catalytic Materials and Devices
Xudong Wang 1
1 , University of Wisconsin, Madison, Madison, Wisconsin, United States
Show AbstractRecent discovery of the piezotronic effect revealed that when a strain is experienced by a piezoelectric semiconductor material or device, it can introduce interfacial charge redistribution and lead to significant performance gain or new functionality. In this talk, we will discuss the coupling of piezoelectric polarization and the intrinsic electric field in a space charge region for the purpose of tuning charge transport behaviors in Wurtzite materials. Three piezotronic-enhanced or enabled applications will be introduced as successful examples. The piezotronic effect has been applied to the ZnO/PbS quantum dot (QD) heterojunction for engineering the interfacial band structure and depletion region. This method escalated the solar energy efficiency by 30% when a relatively small strain -0.25% was applied to the QDSC under low-intensity illumination. The enhancement of short circuit current and efficiency was mostly due to the expansion of depletion region in PbS, as a result of piezoelectric polarization-induced charge redistribution at the ZnO/PbS interface. Similarly, piezotronic effect could enhance the oxygen evolution reaction (OER) in photoelectrochemical (PEC) systems. In a Ni(OH)2-decorated ZnO photoanode system, appreciably improved photocurrent density of sulfite and hydroxyl oxidation reactions were obtained by physically deflecting the photoanode. A largely enhanced performance of PEC photoanodes was also obtained by ferroelectric polarization-endowed band engineering on the basis of TiO2/BaTiO3 core/shell nanowires. Numerical model was established to calculate the potential distribution across the catalyst/piezoelectric/electrolyte heterojunction and reveal favorable electronic band bending as a result of internal piezoelectric polarization. Furthermore, the strain-induced piezopolarization can direct interact with electrochemical processes, which is denoted as the piezocatalysis effect. By straining a ferroelectric PMN-PT beam in water, we experimentally demonstrated that piezoelectric potential can raise the energy of electrons at the surface of piezoelectric material (or electrode) to such a level that is sufficient to drive proton reduction reactions within its immediate vicinity. A piezocatalyst can realize self- or remotely-activated electrochemical processes from ambient oscillations or applying acoustic waves, respectively. In summary, interfacing between piezotronics and electrochemical systems will open a new route for engineering the catalytic properties of conventional catalysts via mechanical straining.
5:00 PM - *ES4.5.02
Trions and Excitons Modulation in Two-Dimensional MoS2 by Acoustic Means
Amgad Rezk 1 , Benjamin Carey 1 , Leslie Yeo 1 , Kourosh Kalantar-zadeh 1
1 , RMIT, Melbourne, New South Wales, Australia
Show AbstractTwo-dimensional molybdenum disulfide (2D MoS2) has attracted increasing attention in recent years due to its fascinating physical and chemical properties.1-7
A very recent discovery is the observation that 2D MoS2 is by nature piezoelectric, if it contains an odd number of layers but not so in even layered configurations.7 This appears to originate from the opposite orientation of alternating layers in 2H-MoS2, resulting in an inversion symmetry breaking only in odd-numbered layers, whereas systems with an even number of layers remain centrosymmetric, losing its piezoelectric response. Wu et al.7 subsequently investigated the piezoelectric properties of one to six layered MoS2 through continuous stretching and releasing of the flakes with a strain frequency of 0.5 Hz, in which the piezoelectric coupling coefficient was estimated to be ∼5.08% for a single layer and observed to reduce significantly for 3 and 5 layers.
In this work, by exploiting the very recent discovery of the piezoelectricity in odd-numbered layers of 2D MoS2, we show the possibility of reversibly tuning the photoluminescence of single and odd-numbered multilayered MoS2 using high frequency sound wave coupling.5 We observe a strong quenching in the photoluminescence associated with the dissociation and spatial separation of electrons–holes quasi-particles at low applied acoustic powers. At the same applied powers, we note a relative preference for ionization of trions into excitons. This work also constitutes the first visual presentation of the surface displacement in one-layered MoS2 using laser Doppler vibrometry. Such observations are associated with the acoustically generated electric field arising from the piezoelectric nature of MoS2 for odd-numbered layers. At larger applied powers, the thermal effect dominates the behaviour of the two-dimensional flakes. Altogether, the work reveals several key fundamentals governing acousto-optic properties of odd-layered MoS2 that can be implemented in future optical and electronic systems.
1. K. J. Berean, J. Z. Ou, T. Daeneke, B. J. Carey, E. P. Nguyen, Y. Wang, S. P. Russo, R. B. Kaner and K. Kalantar-zadeh, Small 11, 5035 (2015).
2. K. Kalantar-zadeh, J. Z. Ou, T. Daeneke, M. S. Strano, M. Pumera and S. L. Gras, Adv. Funct. Mater. 25, 5086 (2015).
3. E. P. Nguyen, B. J. Carey, J. Z. Ou, J. Van Embden, E. D. Gaspera, A. F. Chrimes, M. J. S. Spencer, S. Zhuiykov, K. Kalantar-zadeh and T. Daeneke, Adv. Mater. 27, 6225 (2015).
4. J. Z. Ou, A. F. Chrimes, Y. Wang, S. Y. Tang, M. S. Strano and K. Kalantar-zadeh, Nano Lett. 14, 857 (2014).
5. A. R. Rezk, B. Carey, A. F. Chrimes, D. W. M. Lau, B. C. Gibson, C. Zheng, M. S. Fuhrer, L. Y. Yeo and K. Kalantar-zadeh, Nano Lett. 16, 849 (2016).
6. Q. H. Wang, K. Kalantar-Zadeh, A. Kis, J. N. Coleman and M. S. Strano, Nat. Nanotech. 7, 699 (2012).
7. W. Wu, L. Wang, Y. Li, F. Zhang, L. Lin, S. Niu, D. Chenet, X. Zhang, Y. Hao, T. F. Heinz, J. Hone and Z. L. Wang, Nature 514, 470 (2014).
5:30 PM - *ES4.5.03
Achieving Ultrahigh UV Responsivity of Single Nonpolar A-Axial GaN Nanowire with Asymmetric Piezopotential Distribution via Piezo-Phototronic Effect under Optimized Strain
Chuan-Pu Liu 1 , Chen-Yu Tsai 1 , Kapil Gupta 1
1 , National Cheng Kung Univ, Tainan Taiwan
Show AbstractIntuitively, piezotronics effect is widely expected to facilitate the optimization process by fine tuning Schottky barrier height (SBH) with external stress through piezopotential. However, piezopotential distribution will definitely interact with free carriers and optimally affect the distribution of free carriers and thus piezopotential itself dynamically. The interplay can be even complicated by the excess carriers excited by lights of various powers. The dynamic coupling between stress-induced piezopotential distribution and light-induced carrier concentration distribution under the field of piezo-phototronics seems to be a daunting task and still lacks of complete understanding experimentally.
In present study, the interplay among the external strain, light illumination and intrinsic carrier concentration representing piezo-phototronic coupling is systematically and quantitatively examined. A comprehensive analysis on the dependence of the carrier screening effect on both the strain-induced SBH and carrier trapping effect, induced by the unique piezopotential distribution in a strained a-axial GaN NW, has been performed. In this study, when applying an optimum tensile strain of 0.012% on an a-axis GaN NW with a carrier concentration of 6.2×1017cm-3, we demonstrate the highest UV responsivity of 1.3x105 (A/W) under the illumination intensity of 39.36 mW/cm2. The nonlinear responsivity enhancement under strain is explained by the competition between the SBH lowering effect and carrier trapping effect induced by the unique piezopotential distribution in a single strained a-axial GaN NW. Therefore, this work provides a new design rule for better utilizing piezopotential in coupling with light to achieve the highest performance in optoelectric devices incorporating piezo-phototronics. The results from this study suggest that a-axial GaN NWs hold promise for use in high performance piezotronic- or piezo-phototronic-based sensors.
ES4.6: Poster Session I: Nanogenerators and Piezotronics
Session Chairs
Christian Falconi
Wenzhuo Wu
Wednesday AM, April 19, 2017
Sheraton, Third Level, Phoenix Ballroom
9:00 PM - ES4.6.01
Mechanoluminescence Color Conversion from ZnS-Embedded-Polydimethylsiloxane Elastomer Functionalized with Fluorescent Dye
Soon Moon Jeong 1 , Seongkyu Song 1 , Hyunmin Kim 1 , Kyung-Il Joo 2 , Hideo Takezoe 3
1 , Daegu Gyeongbuk Institute of Science and Technology, Daegu Korea (the Republic of), 2 , Kyungpook National University, Daegu Korea (the Republic of), 3 , Toyota Physical and Chemical Research Institute, Aichi Japan
Show AbstractMechanoluminescence (ML) is attractive for energy-saving technology because it can be generated by all available mechanical vibrations in nature. ML has potential applications in colorful displays and white-light sources. However, most ML phenomena show weak intensity and limited color expression due to the destructive nature of the process. Recently, the color manipulation of mechanoluminescence (ML) has been demonstrated by mixing different-color-emitting ML particles or controlling dopant concentration. However, the use of different ML materials usually restrain the various color expression because there has been a limited number of reported ML materials. Here, we show a red luminescence by complete color conversion from a spontaneously formed fluorescent-dye-diffused elastomeric zinc sulfide (ZnS) composite [1]. The generation of red light could be achieved by spontaneously diffused 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) in polydimethylsiloxane (PDMS) which fully absorbs mechanically excited green ML. Based on this approach, we could achieve color-tuning from green to red and were able to demonstrated various-color-emitting optomechanical display by employing DCJTB.
[1] S. M. Jeong, S. Song, H. Kim, K. –I. Joo and H. Takezoe, Adv. Funct. Mater. 26, 4848 (2016).
9:00 PM - ES4.6.02
PCE Improved TENG with Gear Mechanism Based Mechanical Energy Transfer System
Wook Kim 1 , Dukhyun Choi 1
1 , Kyung Hee University, Yongin-si Korea (the Republic of)
Show AbstractThe performance of TENGs is mainly affected by the level of input mechanical energy and characteristics of triboelectric materials. Furthermore, the output performance of TENGs could be changed with mechanical structure and external electrical circuit. In this study, we investigated the effect of mechanical energy transfer system on TENG for enhancing both output performance and power conversion efficiency (PCE). To achieve objectives, we applied the gear mechanism on mechanical structure to improve the contact rate. We set an input gear with a specific size (rin) and a working gear with a smaller size (rw < rin) and connected these gears to enhance the working frequency (fw) at the working gear. We measured the output energy under a constant input energy with different size of the working gear (rw). We prepared gears with gear ratios (rin/rw) of 1, 1.7, and 5. Under the constant input energy, the peak voltage and current from our TENG system were enhanced up to the maximum of 3.6 times and 4.4 times, respectively. Also, the PCE was maximally increased up to 7 times under input frequency of 1.5 Hz with gear ratio of 5. To understand the effect of energy transfer mechanism on TENG, we charged a capacitor with external electrical circuit. Under the input frequency of 4.5 Hz, we obtained a 3 times enhanced rectifying voltage at a gear ratio of 5. Remarkably, capacitor voltage was enhanced up to about 8 fold in using our TENG system. It is attributed that our gear-based TENG system could improve simultaneously the magnitude as well as the generation time of output power, finally enhancing output energy. Therefore, our TENG system could provide an effective way to enhance the output performance and PCE of TENGs operating at a given input energy.
9:00 PM - ES4.6.03
Kinematically Driven Triboelectric Nanogenerator as a Practical Power Source
Divij Bhatia 1 , Dukhyun Choi 1
1 , Kyung Hee University, Yongin Korea (the Republic of)
Show AbstractTriboelectric nanogenerators (TENG) can convert various forms of wasted mechanical energy in our environment into useful electrical energy that can power wireless sensor nodes constituting an internet of things (IoT) application. In this work we demonstrate a TENG system that utilizes mundane rotation energy to power a temperature and humidity wireless sensor node. Firstly we convert low frequency rotation input into high frequency using a custom gear system. A windup spring based mechanism was used to fix the output rotation frequency. Then using a cam the high frequency rotation is converted into linear motion to drive multiple verticle contact mode TENGs. A power converter system constituting a transformer and charge pump circuit is used to reliably power a temperature and humidity sensor that can periodically transmit data wirelessly via bluetooth to any smart device like a laptop or mobile phone. A number or such renewably TENG-powered wireless nodes can provide a great estimate of environmental conditions in industry applications sensitive to temperature and humidity changes. Automated control systems can be designed around these TENG-powered wireless nodes to ensure proper operation by self-adjusting critical settings or triggering a total system shutdown under emergency.
9:00 PM - ES4.6.04
High-Output Power of the Triboelectric Nanogenerator Made from Recycling Rice Husks
Chih-Kai Chang 1 , Jyh Ming Wu 1
1 , National Tsing Hua University, Hsinchu Taiwan
Show AbstractThis work, we are the first to discover the high-output current density of the triboelectric nanogenerator (TENG) using rice husks as a source material. The raw rice husks (RH) can be directly phase transited into the amorphous SiO2 (RHSiO2) structure with highly nanoporous fragments by the thermal annealing with additional acid hydrolysis process. The RHSiO2-TENG's configuration is designed by polytetrafluoroethene (PTFE) and RHSiO2 films, which are chemically and thermally more stable than the metallic film. The pore size around 20–40 nm is widely distributed throughout the SiO2 fragments that possess rich Si–O–Si and OH stretching bonds with strong tendency of repulsing electron because the H atoms have an extremely low electron affinity, leading to the RHSiO2 film exhibits much lower electron affinity when compared with the commercial SiO2 nanoparticles. As a consequence, the area power density of the RHSiO2 triboelectric nanogenerator (RHSiO2-TENG) reaches 0.84 W m-2 with a peak short circuit current density of 5.7 mA m-2. Such a short-circuit current density is almost among the highest reported value based on dielectric-to-dielectric mode triboelectric nanogenerators. Rice husk possess many advantageous traits such as their light weight, low cost, being environmentally friendly, high porosity, excellent robustness, exceptionally chemical and thermal stability for superior corrosion resistance, makes it a valuable material for industrial applications.
9:00 PM - ES4.6.05
Fabrication of a Highly Transparent Nanostructured Triboelectric Nanogenerator for the Application of an Efficient Hybrid Energy Harvester
Donghyeon Yoo 1 , Dongwhi Choi 1 , Dong Sung Kim 1
1 , Pohang University of Science and Technology (POSTECH), Pohang Korea (the Republic of)
Show AbstractTriboelectric nanogenerators (TENGs), working based on a coupling of contact electrification and electric induction, have positioned as one of the promising energy harvesters, since the first report in 2012 due to their high accessibility from the ubiquitous characteristics of contact electrification. Recently, the possibility of harvesting water droplet-induced mechanical energy from TENGs is reported and several efforts are involved in increasing the electrical output performance and finding the practical applications. Along with it, a concept of hybrid energy harvesters, which can complementary harvest solar and raindroplet-induced mechanical energy, emerges as one of the main applications. The hybrid energy harvesters are composed of a solar cell and the attached TENG on its surface. They mainly harvest solar energy and subsidiary droplet-induced mechanical energy. However, the previous reported hybrid energy harvesters have a fundamental matter of the decrease in solar cell efficiency because the TENG hinders light absorption of the solar cell. Herein, we reported a new type of hybrid energy harvesters, where a solar cell is undisturbed by a TENG. The TENG is composed of 200 nm-structured quartz glass and a layer of AgNW, which give highly transparent characteristics. From the investigation of current-voltage characteristics, the efficiency of the solar cell in the present hybrid energy harvesters is similar with that of solar cell solely. Finally, the hybrid system shows self-cleaning characteristics and the corresponding droplet-induced mechanical energy generation due to the unique nanostructures. From the results, we believe the present research suggests a TENG, which has high potential to be applied in the fields of solar energy industry.
9:00 PM - ES4.6.06
Self-Recovering Triboelectric Nanogenerator as Active Multifunctional Sensors
Qingliang Liao 1 , Mingyuan Ma 1 , Yue Zhang 1
1 , University of Science and Technology Beijing, Beijing China
Show AbstractA novel self-recovering triboelectric nanogenerator (STENG) driven by airflow is designed as active multifunctional sensors. A spring was composed to the STENG and enable the nanogenerator to have self-recovering characteristic. The maximum output voltage of the fabricated STENG is about 251 V. The instantaneous output current and power reaches 56 μA and 3.1 mW on a load of 1MΩ.The STENG can act as active multifunctional sensors that include humidity sensor, airflow rate sensor and motion sensor. The STENG-based humidity sensor has a wide detection range of 20%-80%, rapid response time of 18 ms and recovery time of 80 ms. This work expands practical applications of triboelectric nanogenerators as active sensors with advantages of simple fabrication and cost-effective.
9:00 PM - ES4.6.07
Optimization of Design Parameters towards Enhancing the Output Performance in Flexible Hybrid Triboelectric and Piezoelectric Nanogenerator
Xiya Yang 1 , Walid Daoud 1
1 School of Energy and Environment, City University of Hong Kong, Hong Kong China
Show AbstractInterests in combined effect generators in mechanical energy harvesting [1-3] have rapidly grown in recent years due to their wide utilization without being limited by time or environment conditions. Since mechanical energy is easily obtainable in the living environment, conversion of mechanical energy to electricity using micro generators has become an approach to alleviate the serious problem of energy shortages.
Both piezoelectric and triboelectric effects can be utilized to design and realize good performance generators with high energy conversion efficiency. In this work, a flexible hybrid triboelectric and piezoelectric effects generator (TPEG) with a sandwich structure of aluminum - polydimethylsiloxane (PDMS) / polyvinylidene fluoride (PVDF) composite film [PPCF] - carbon is fabricated first for the purpose of converting mechanical energy to electricity. Enhanced by surface modification of PPCF with zinc oxide (ZnO) nanorods [4], the TPEG generated an open-circuit voltage (Voc) of ~40V and a short-circuit current (Isc) of 0.28μA with maximum power density of ~70mW/m2 and maximum efficiency of 34.56%. Subsequently, experimental studies on the impacts of design parameters towards improving the final output potential and the energy conversion efficiency were conducted by adjusting the factors of gap distance (d[cm]) between the triboelectric pair (Al and PPCF); the frequency (f[Hz]) of “press-release” by the linear motor, applied velocity (v[m/s]), and compression force (F[N]). The output performance of TPEG for experimental studies of the optimized gap distance, frequency, maximum velocity and compression force are analyzed through Voc, Isc, maximum power delivered to the external load and maximum conversion efficiency. Overall, the flexible hybrid TPEG with optimized design parameters is proved to be an efficient generator in mechanical energy conversion with promising output potential as well as high conversion efficiency.
References
[1] Zhu, G.; Peng, B.; Chen, J.; Jing, Q.; Wang, Z.L. Triboelectric nanogenerators as a new energy technology: From fundamentals devices to applications. Nano Energy 2015, 14, 126-138.
[2] Yang, Y. and Wang, Z. L., Hybrid energy cells for simultaneously harvesting multi-types of energies. Nano Energy 2015, 14, 245-256.
[3] Lin, L.; Xie, Y. N.; Niu, S. M.; Wang, S. H.; Yang, P. K.; Wang, Z. L., Robust Triboelectric Nanogenerator Based on Rolling Electrification and Electrostatic Induction at an Instantaneous Energy Conversion Efficiency of similar to 55%. ACS Nano 2015, 9, 922-930.
[4] Yang, X.Y. and Daoud, W. A., Triboelectric and Piezoelectric Effects in a Combined Tribo-Piezoelectric Nanogenerator Based on Interfacial ZnO Nanostructure. Adv. Funct. Mater. 2016, doi:10.1002/adfm.201602529.
9:00 PM - ES4.6.08
Ordered PZT Arrays Grown on Silicon Substrates Using Glancing Angle Pulsed Laser Deposition on Self-Assembled Nanotemplates
Domingo Mateo-Feliciano 1 , Derick Gonzalez 2 , Mahesh Hordagoda 1 , Pritish Mukherjee 1 , Sarath Witanachchi 1
1 , University of South Florida, Tampa, Florida, United States, 2 , University of Puerto Rico at Mayaguez, Mayaguez, Puerto Rico, United States
Show AbstractThin films and nanostructures of the piezoelectric material Lead Zirconium Titanium Oxide (PZT) offer a multitude of applications in Piezotronics. While the growth of PZT thin films is well established, methodologies for the fabrication of vertically-aligned and spatially ordered PZT columns in nanoscale are not common. In this work an approach that uses a self-assembled nanoparticle template in a glancing angle pulsed laser deposition (GAPLD) process is presented. As the first step, commercially available silica nanospheres (SNS) with diameter in the range of 250nm to 800 nm were self-assembled in a closed-pack hexagonal configuration as a monolayer using the Langmuir-Blodgett method. As the second step, a thin lanthanum strontium manganite oxide (LSMO) was grown by laser ablation on the template to serve as a bottom electrode as well as the seed layer for the subsequent PZT growth by GAPLD. Due to the shadowing effect introduced by the GAPLD, PZT columns in the form of hexagonal nanopillars evolved over the spatially ordered nanotemplate. Morphological, structural, and piezoelectric properties of these structures and their dependence on the nanoparticle size of the template will be presented.
9:00 PM - ES4.6.09
One-Step Fabrication of the Pattern Assisted Triboelectric Nanogenerator Operated by the Discrete Liquid-Solid Contact Electrification Phenomenon
Dongwhi Choi 1 , Donghyeon Yoo 1 , Dong Sung Kim 1
1 , POSTECH, Pohang Korea (the Republic of)
Show AbstractIn 2013, the phenomenon of discrete liquid-solid contact electrification inside the conventional pipet tip is firstly unveiled by our group. Discrete liquid-solid contact electrification is based on the sequential process of liquid-solid contact and separation. After its discovery, the discrete liquid-solid contact electrification phenomenon is utilized as a fundamental of operation of the various applications such as triboelectric nanogenerators (TENGs) and the self-powered sensors.
Herein, the phenomenon is briefly introduced and then, the fabrication of TENGs utilizing discrete liquid-solid contact electrification is demonstrated. By utilizing the thermal nanoimprinting process, nano-Pattern Assisted TriboElectric Replicable Nanogenerator, called nano-PATERN, can be one-step fabricated; the thermal nanoimprinting process enables not only nano-replication of a contact layer but also simultaneous integration with the electrode layer, which is an essential prerequisite for constructing nanotopographical TENGs.
The remarkable functional characteristics of high flexibility and transparency confirm significant benefits of the nano-PATERN for various applications such as solar cell applied-hybrid energy harvesters. Consequently, this study makes an important contribution for the mass production and practical utilization of TENGs.
9:00 PM - ES4.6.10
Spontaneous Dipole Modulation of Ferroelectric BaTiO3 NPs-Polymer Composite for Performance Enhancement of Triboelectric Nanogenerators
Sung-Ho Shin 1 , Yang Hyeog Kwon 1 , Joo-Yun Jung 2 , Junghyo Nah 1
1 , Chungnam National Univ, Daejeon, SE, Korea (the Republic of), 2 Department of Nano Manufacturing Technology, Korea Institute of Machinery and Materials, Daejeon, Chungchungnam-Do, Korea (the Republic of)
Show AbstractRecently, triboelectric nanogenerators (TEGs) have been of interest as energy harvesting devices, thanks to their relatively simple fabrication process for their exceptionally high output power density. Triboelectrically generated output power can be greatly affected by choices of contacting materials, surface patterning, and chemical surface functionalization. However, the coupling effects of spontaneous dipoles inside the composite due to polarized ferroelectric NPs have not been much investigated. In this work, we report a novel method to extend the performance limit of TEGs by introducing polarized ferroelectric nanoparticles (NPs) inside the composite. Triboelectric output voltage and current have been modulated by varying the mixing ratio of BaTiO3 NPs to PDMS and differently polarizing BTO NPs inside the composite. In this way, the roles of permittivity and polarized dipole modulation in output power generation were systematically investigated and adopted for performance enhancement of the TEGs. Our results show that peak output power density of the TEGs can be greatly enhanced either by increasing permittivity or aligning polarization domain of the composite layer, exhibiting over 5-fold increases in output power density. The approach introduced here is a simple, effective, and cost-competitive route for the high performance TEGs and can be adopted in maximizing the output power of TEGs.
9:00 PM - ES4.6.11
Performance Enhanced Triboelectric Nanogenerator via Large-Area and Defectless Nanograting Enabled by Multistep Pattern Downscaling Lithography
Hee seung Wang 1 , Chang Kyu Jeong 1 , Keon Jae Lee 1
1 , KAIST, Daejeon Korea (the Republic of)
Show AbstractThe triboelectric nanogenerator (TENG) has been developed as a promising technology for mechanical energy harvesting with high output power, easy fabrication, low cost advantage and structure diversity of device. To obtain incomparable performance of TENG, many researchers have developed various methods including chemical and topographical surface engineering for larger contact area and triboelectric charge. Among them, it has been reported that significantly enhanced output-power can be generated owing to simply nano-fabricated patterns, so this approach has gained much recent-attention. In this research, we apply a seamless and ultralong 100 nm-pitch nanograting pattern assisted triboelectric nanogenerator. Based on the process of stitch-less and repetitive pattern downscaling lithography by alternatively depositing spacers/pattern receiver layers and etching, we introduce wafer-scale defectless nano-grating template with extremely high aspect ratio (4,000,000:1). Replicating this template to flexible substrate, the disposable nano-patterned plastic followed electrode deposition serves as friction surface of TENG to increase the output performances of TENG by forming the large effective contact surface area. The nanograting based-surface for TENG presented the increase of corresponding current and voltage as well as output power compared to the natural flat surface. This novel technology for triboelectric energy harvesting can induce new electronics innovations in triboelectricity and widely expand its applications as not only efficient energy sources but also various sensor.
9:00 PM - ES4.6.12
Design of the Piezoelectric Energy Harvesting Modules for Self-Powered Smart Roadways
Inki Jung 1 2 , Youn-Hwan Shin 1 2 , Sang Tae Kim 1 , Chong-Yun Kang 1 2
1 Center for Electronic Materials, Korea Institute of Science and Technology, Seoul Korea (the Republic of), 2 KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul Korea (the Republic of)
Show AbstractWith the advent of environmental issues, various energy harvesting technologies have received research attention for making use of the ambient energy sources. Piezoelectric energy harvesters are one of the most attractive technologies to recycle the wasted kinetic energy into the electricity. Herein, we demonstrate a piezoelectric energy harvesting module based on polyvinylidene fluoride (PVDF) to utilize the traffic induced energy on roadways. In contrast to the ceramic-based piezoelectrics, PVDF maintains inherent flexibility and durability despite the mechanical shock caused by the vehicles on roadways. In order to construct a harvesting module, we first structurally optimized harvesting elements based on Finite Element Analysis (FEA). Also, tThe devices were are then designed such so that parallel-connected unit harvesters effectively can lower the overall impedance. A prototype harvester prototype module was was fabricated with 15×15 cm2 size, and we performed measuredments under model roadway systems. The maximum output power density of 4.9 W/m2 was observed under 250 kg axial load and 10 km/h wheel speed. This macro-scale (~W/m2) energy harvesting technology provides us with the opportunity to expect smart roadways to come in the near future.
9:00 PM - ES4.6.14
Investigation of Aluminum Nitride Films for a Vibration Energy Harvesting Device
Kun-Mao Huang 1 , Hsuan-Ying Chen 1 , Kun-Dar Li 1
1 Department of Materials Science, National University of Tainan, Tainan Taiwan
Show AbstractDue to the stimulation of the environmental issues, over the past decades many energy-related researches were focused on the subjects of energy harvesting materials, such as solar cells, thermoelectric generators and piezoelectric transducers. Aluminum nitride becomes one of the promising materials for the applications in the energy harvester by virtue of its good piezoelectric property. Taking the advantages of the low temperature process and high deposition rate, DC reactive magnetron sputtering was applied in this study to prepare AlN thin films for a vibration energy harvesting device. By changing the sputtering parameters, such as N2 ratio, sputtering power and substrate temperature, different morphologies and crystal structures of AlN films were produced. Afterwards, a vibration energy harvesting device of AlN films deposited on a polyimide (PI) substrate with Al electrode was fabricated and the piezoelectric property of this device was further evaluated. From the SEM images, XRD analysis and piezoelectric property measurement, the influence of sputtering parameters on the morphology and piezoelectric property of AlN films was distinctly demonstrated. While the sputtering power was increased from 80W to 160W, it showed that a preferred crystal plane of (002) could be obtained, and the grains of AlN films with a size of ~150nm on the substrate were observed apparently. The vibration energy harvesting device with (002) preferred orientations would have a higher peak-to-peak voltage and power. In addition, the experimental results also demonstrated that an appropriate substrate temperature can improve the crystallinity of AlN films to enhance the piezoelectric property. The highest power density in this study reached about 140mW under the vibration frequency of 20Hz.
9:00 PM - ES4.6.15
Sponge TENG Generating Stable Output in Various Mechanical Energy and Harsh Environments
Hwang Heejae 1 , Dukhyun Choi 1
1 Mechanical Engineering, Kyunghee University, Yongin Korea (the Republic of)
Show AbstractHarvesting energy from our living environment is an effective approach for sustainable, maintenance-free, and green powder source for wireless, portable, or implanted electronics. So, as moving into a ubiquitous socity, wasted energy around us is received attention to be harvested. Triboelectric nanogenerator(TENG) is one of the solution. But, in order to apply TENG to real life, there are two factors. First, it is that stable energy generating in ant environments such as in high humidity. Second, it is that shape of generator is critically important in order to apply various mechanical energy source. In various previous research, almost all comprises two plate and spacer, roughly. The components are managed to restrict TENG to applications of narrow range. In this study, we focused on triboelectric nanogenerators that can harvest in various situation and harsh environments in order to overcome the weakness of TENG. We fabricated milti-shape sponge type TENG from Al particles to utilize diverse mechanical energy source in daily life and avoid from surrounding condition, such as humidity and dust. Also they have a porous fabrication, like a sponge. So, it can use a application resisting an Impulse. We expect this study pioneers application of TENG to our life.
9:00 PM - ES4.6.16
Enhanced Performance of Triboelectric Nanogenerators by Localized Surface Plasmon Resonance Effect with Silver Nanoparticles
Songhwa Chae 1 , Dukhyun Choi 1
1 , Kyung Hee University, Yongin Korea (the Republic of)
Show AbstractNowadays, energy crisis becomes a global problem and there are a lot of efforts to develop the use of green energy source. As a solution to this problem, energy harvest system received world attention. In 2012, energy generating based on the conjunction of triboelectric effect and electrostatic induction is presented as triboelectric nanogenerators (TENGs), which can produce electrical power from ambient environment such as human motion, vibration, walking, wind and so on. TENGs are expected to be used in the wearable and self-powered devices. In this study, we report that using Localized surface plasmon resonance (LSPR) effect enhance power of TENGs. We used ITO-coated PET film as electrode and polydimethylsiloxane (PDMS) as negatively charged material. We prepared PDMS thin film without micro/nano morphology and bonded it to ITO-coated PET film for top layer. Then, for bottom layer, silver was deposited 20nm on ITO-coated PET film via thermal evaporator, next annealing process to the film was conducted for silver nanoparticles (Ag-NPs) forming. When the light hit the Ag-NPs, it can exhibit LSPR effect. The LSPR effect can create strong near-field electromagnetic fields and far-field propagating waves. Therefore, the LSPR effect from Ag-NPs can improve the performance of TENGs. Finally, we compared the performances of TENGs in with or without light condition. We expect this integration system can provide a new hybrid TENGs for transparent devices application.
9:00 PM - ES4.6.17
Template-Assisted Hydrothermal Growth of Aligned Zinc Oxide Nanowires for Piezoelectric Energy Harvesting Applications
Canlin Ou 1 , Sohini Kar-Narayan 1
1 , University of Cambridge, Cambridge United Kingdom
Show AbstractA flexible and robust piezoelectric nanogenerator (NG) based on a novel hybrid polymer-ceramic nanocomposite structure for piezoelectric energy harvesting (EH) applications has been successfully fabricated via a simple yet cost-effective, scalable and low-temperature template-assisted hydrothermal synthesis method. Vertically aligned arrays of dense and uniform zinc oxide (ZnO) nanowires (NWs) with high aspect ratios were grown within flexible nanoporous polycarbonate (PC) templates. The synthesised ZnO NWs are polycrystalline and have demonstrated a strong alignment along (100) preferred orientation. The as-grown high-quality ZnO NWs embedded within soft and flexible PC templates can be directly integrated into NGs with minimal post-possessing treatment, and the resulting NGs are particularly robust and relatively immune to detrimental environmental factors and mechanical failure, as the constituent ZnO NWs remain embedded and protected inside the polymer matrix. A single NG of area ~3 cm2 and thickness ~12 μm has generated a peak output power density of ~1.6 W/m3 across a load resistance of ~1 MΩ, and its energy conversion efficiency was found to be ~4.2%, which is comparable to previously reported values for ZnO NWs. The mechanical stability of the NGs has also been comprehensively evaluated by various piezoelectric EH tests, and it has shown that these flexible ZnO-PC based NGs are particularly robust and exhibit superior stable EH performance over time. Furthermore, Li has been doped to modify the piezoelectric and ferroelectric properties of ZnO. Long and well-aligned yet polycrystalline ZnO NWs doped with different Li concentration have been successfully synthesised. A decrease in a and c lattice parameters and an increase in the c/a ratio with increasing Li concentration have been observed in the Li-doped NWs, which confirms Li has successfully partially substituted Zn. Their ferroelectric and piezoelectric properties are subsequently assessed.
9:00 PM - ES4.6.19
A Flexible Energy Harvester Based on a Lead-Free and Piezoelectric BCTZ Nanoparticle–Polymer Composite
Changyeon Baek 1 , Kwi-Il Park 2 , Do Kyung Kim 1
1 , KAIST, Daejeon Korea (the Republic of), 2 Energy Engineering, Gyeongnam National University of Science and Technology, Jinju Korea (the Republic of)
Show AbstractLead-free piezoelectric 0.5(Ba0.7Ca0.3)TiO3–0.5Ba(Zr0.2Ti0.8)O3 (BCTZ) nanoparticles (NPs) composed of earth-abundant elements were adopted for use in a flexible composite-based piezoelectric energy harvester (PEH) that can convert mechanical deformation into electrical energy. The solid-state synthesized BCTZ NPs and silver nanowires (Ag NWs) chosen to reduce the toxicity of the filler materials were blended with a polydimethylsiloxane (PDMS) matrix to produce a piezoelectric nanocomposite (p-NC). The naturally flexible polymer-based p-NC layers were sandwiched between two conductive polyethylene terephthalate plastic substrates to achieve a flexible energy harvester. The BCTZ NP-based PEH effectively generated an output voltage peak of ∼15 V and a current signal of ∼0.8 μA without timedependent degradation. This output was adequate to operate a liquid crystal display (LCD) and to turn on six blue light emitting diodes (LEDs).
9:00 PM - ES4.6.20
Eco-Friendly Smart Mobile Pouch Triboelectric Nanogenerator for Self-Powered Wireless Power Transfer Applications
Arunkumar Chandrasekhar 1 , Nagamalleswara Rao Alluri 1 , Sudhakaran M.S.P 1 , Young Sun Mok 1 2 , Sang-Jae Kim 1
1 , Jeju National University, Jeju Korea (the Republic of), 2 Department of Chemical Engineering, Pennsylvania State University, University Park, PA , Pennsylvania, United States
Show AbstractA Smart Mobile Pouch Triboelectric Nanogenerator (SMP-TENG) is introduced as a promising eco-friendly approach for scavenging biomechanical energy for powering next generation intelligent devices and smart phones. This is a cost-effective and robust method for harvesting energy from human motion, by utilizing worn fabrics as a contact material. The SMP-TENG is capable of harvesting energy in two operational modes: lateral sliding and vertical contact and separation. Moreover, the SMP-TENG can also act as a self-powered emergency flashlight and self-powered pedometer during normal human motion. A wireless power transmission setup integrated with SMP-TENG is demonstrated. This upgrades the traditional energy harvesting device into a self-powered wireless power transfer SMP-TENG. The wirelessly transferred power can be used to charge a Li-ion battery and light LEDs. The SMP-TENG opens a wide range of opportunities in the field of self-powered devices and low maintenance energy harvesting systems for portable and wearable electronic gadgets.
Acknowledgement
This work was supported by the Jeju Sea Grant College Program 2016, Funded by the Ministry of Oceans and Fisheries (MOF) and by the National Research Foundation of Korea (NRF) funded by the Korea Government GRANT (2016R1A2B2013831).
9:00 PM - ES4.6.21
Wearable Sensory Glove Using TiO2-ZnO Core-Shell Structures on Flexible Ti-Wires via Chemical Oxidation/Deposition Method
Nagamalleswara Rao Alluri 1 , Arunkumar Chandrasekhar 2 , Ji Hyun Jeong 1 , Sang-Jae Kim 2
1 Mechanical Engineering, Jeju National University, Jeju City, Jeju Island, Korea (the Republic of), 2 Mechatronics Engineering, Jeju National University, Jeju, Jeju Island, Korea (the Republic of)
Show AbstractAbstract:
We report a scalable synthesis of TiO2 nanoparticles-ZnO micro rods based core-shell structures on a micro-meter sized diameter (100 μm) and few centimeter sized lengths of Ti wire via chemical oxidation/deposition method. It is highly desirable to scale down the wearable device dimensions at micro/nanoscale with high repeatability and sensitivity. The phase structure and surface morphology was investigated by Raman spectra and scanning electron microscope confirming the well crystalline TiO2 anatase nanoparticles and hexagonal wurtzite structure of ZnO micro rods. The fabricated wire based device (Ag/TiO2-ZnO/Ag) has a capability to convert the tiny mechanical motions into electricity using the piezoelectric behavior of ZnO micro rods. The classification/detection of joint or finger movements is possible by the device output voltage or current. The reliability of the sensor depends on the generated electric potential, location of the device on the glove, strain generated by the joints, and flexibility of the device. Therefore, the flexible wire based wearable gloves useful for in-patient rehabilitation, finger Braille typing and directional bending of the human body. These efficient smart devices (battery free) have a great demand in implantable biomedical devices, optical sensors and chemical sensors.
Keywords: TiO2-ZnO core-shell structures, piezoelectric behavior, energy harvesting, self-powered device, and chemical oxidation
Acknowledgement:
This work was supported by the Jeju Sea Grant College Program 2016 Funded by the Ministry of Oceans and Fisheries (MOF) and by the National Research Foundation of Korea (NRF) funded by the Korea Government GRANT (2016R1A2B2013831).
9:00 PM - ES4.6.22
Triboelectric–Electromagnetic Hybrid Generator for Harvesting Blue Energy
Zhen Wen 1 2 , Hengyu Guo 2 , Min-Hsin Yeh 2 , Yunlong Zi 2 , Xin Wang 2 , Xuhui Sun 1 , Zhong Lin Wang 2
1 , Soochow University, Suzhou China, 2 Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
Show AbstractAlthough blue energy is capable of meeting all of our energy needs, there is no effective way to harvest it due to its low frequency and irregular amplitude, which may restrict the application of traditional power generators. Here we propose a hybrid nanogenerator that consists of a triboelectric nanogenerator (TENG) and an electromagnetic generator (EMG) for harvesting ocean energy. Since the mechanical transmission from the external mechanical source to the TENG is through a noncontact force between the paired magnets, a fully isolated packaging of TENG part can be easily achieved. At the same time, combining with metal coils, these magnets can be fabricated to be EMG. The contrastive characteristics and advantages of outputs indicate that the TENG is irreplaceable for harvesting low frequency (<5 Hz) energy, which fits the frequency range for most of the water wave based blue energy, while EMG is able to produce larger output at high frequencies (>10 Hz). The complementary output can be maximized and hybridized for harvesting energy in a broad frequency range. Notably, various different kinds of hybrid nanogenerators could generate electricity under either rotation mode or fluctuation mode to collect energy in ocean tide, current, and wave energy. The proposed hybrid nanogenerator renders an effective and sustainable progress in practical applications of the hybrid nanogenerator toward harvesting water wave energy offered by nature.
9:00 PM - ES4.6.25
Flexible and Controllable Piezo-Phototronic Pressure Mapping Sensor Matrix by Organic/Inorganic Hybrid LED Array
Rongrong Bao 1 , Caofeng Pan 1 , Zhong Lin Wang 1
1 , Chinese Academy of Sciences, Beijing China
Show AbstractFunctional tactile sensing device is mandatory for next-generation robotics and human-machine interfaces since the emulation of touching requires large-scale pressure sensor arrays with high-spatial resolution, high-sensitivity, and fast-response[1]. Some tactile sensors fabricated with organic transistors or micro-structured rubber layer pressure sensor arrays have been reported[2]. While with a resolution at the order of millimeter, these devices have not yet met the requirements of artificial skins whose spatial resolution is near 50 μm. Our group have demonstrated pressure sensor array base on piezotronic and piezo-phototronic effects[3]. An ultra-high resolution of 2.7 μm was derived from piezo-phototronic pressure sensor array using ZnO nanowire (NW)/p-GaN LEDs array[4]. These devices provide stable, fast response, as well as parallel-reading detections of spatial pressure distributions. However, the lacking of flexibility with a rigid sapphire substrate prevents the NW-LEDs array device from applications as smart skin; and the pressure measuring range of the device is in a relatively high pressure region. Therefore, a flexible pressure mapping system with moderate spatial-resolution become necessary and may find numerous potential applications in human-machine interfaces.
Recently, we designed and fabricated a flexible LED array composed of PEDOT:PSS and patterned ZnO NWs with a spatial resolution of 7 μm for mapping of spatial pressure distributions by using the piezo-phototronic effect. These devices possess a wide range of pressure measurements from 40 MPa to 100 MPa depending on the growth conditions of ZnO NWs. Furthermore, a LED array composed of PEDOT:PSS and CdS nanorods had been demonstrated for mapping spatial pressure distributions. The emission intensity of which depends on the local strain owing to the piezo-phototronic effect. Therefore, pressure distribution is obtained by parallel-reading the illumination intensities of LED arrays based on electroluminescence working mechanism. The spatial resolution is achieved as high as 1.5 μm. Flexible LED device array has been prepared by CdS nanorod array on Au/Cr/Kapton substrate.
The flexibility and stability of these LED arrays mapping system was studied. The outstanding flexibility, high resolution and controllability of these pressure mapping sensors provide promising technologies for future applications in biological sciences, human-machine interfacing, smart sensor and processor systems, and even defense technology.
Reference
[1] S. C. B. Mannsfeld, B. C. K. Tee, R. M. Stoltenberg, C. V. H. H. Chen, S. Barman, B. V. O. Muir, A. N. Sokolov, C. Reese, Z. Bao, Nature Materials 2010, 9, 859;
[2] B. C. K. Tee, A. Chortos, R. R. Dunn, G. Schwartz, E. Eason, Z. A. Bao, Advanced Functional Materials 2014, 24, 5427.
[3] W. Z. Wu, X. N. Wen, Z. L. Wang, Science 2013, 340, 952.
[4] C. F. Pan, L. Dong, G. Zhu, S. M. Niu, R. M. Yu, Q. Yang, Y. Liu, Z. L. Wang, Nat. Photonics 2013, 7, 752;
9:00 PM - ES4.6.27
Design and Efficiency of Flexible Capacitive Piezoelectric Sensors Based on GaN Wires
Amine El Kacimi 1 2 , Emmanuelle Pauliac-Vaujour 1 2 , Joel Eymery 3 2
1 , CEA-LETI, Grenoble France, 2 , Université Grenoble Alpes, Grenoble France, 3 , CEA-INAC, MEM-NRS, Grenoble France
Show AbstractGallium Nitride (GaN) piezoelectric wire-based flexible hybrid structures provide original solution for mechanical sensing applications. Heavily n-doped GaN wires are grown by Metal Organic Vapor Phase Epitaxy (MOVPE) on sapphire substrate with in-situ injection of silane [1], [2]. It provides N-polar wires with hexagonal cross-section, 10 – 700 µm length (depending on growth time) and a slight conical shape (with 0.3-2° angle).
Horizontally assembled wire-based sensors, obtained by wet chemical functionalization of GaN wires transferred onto flexible substrate, have been previously studied [3], [4]. The operating principles of these devices under bending are analyzed with finite element calculations. In particular, we demonstrate that the wire conical shape is necessary for potential generation due to symmetry breaking of electrostatic dipoles created by piezoelectric field. To optimize the efficiency, this geometry requires dipole alignments, which will be enlightened through the simulation of different regular wire network configurations. This important point is difficult to manage in the practical device realization [5].
To overcome this problem, we propose a new solution integrating as-grown GaN wires directly inside a flexible PDMS layer within a capacitive structure. Charges are vertically separated and potential is collected on the top electrode. These devices can operate under compressive loading or bending constraints and their physical working mechanisms are also analyzed. In these structures, the electrical characteristics can easily be tuned by controlling wire length, density and device dimensions. An equivalent electrostatic dipole model is also proposed to explain the origin of potential generation in such vertical devices. Moreover, FEM calculations coupling semiconductor physics (free carriers) and piezoelectricity are performed to understand the effect of doping on the piezo-potential and device output.
The comparison of both structures shows that vertical devices are more reproducible and provide better output voltage in comparison to horizontal ones and the general design rules will be given. Experimentally, we demonstrate the realization of vertical-wire devices providing up to 3V output voltage.
References :
[1] J. Eymery, et al., Comptes Rendus Phys., vol. 14, no. 2–3, pp. 221–227, Feb. 2013.
[2] R. Koester, et al., Nanotechnology, vol. 21, no. 1, p. 015602, Jan. 2010.
[3] S. Salomon et al., Nanotechnology, vol. 25, no. 37, p. 375502, Sep. 2014.
[4] F. Kim, et al., J. Am. Chem. Soc, vol. 23, no. 18, pp. 4360–4361, Dec 2001.
[5] M. C. P. Wang et al., Mater. Today, vol. 12, no. 5, pp. 34–43, May 2009.
9:00 PM - ES4.6.29
Piezo-Phototronic Enhanced UV Sensing Based on a Nanowire Photodetector Array
Xun Han 1 , Caofeng Pan 1
1 , Beijing Institute of Nanoenergy and Nanosystems, Beijing China
Show AbstractHigh performance and high resolution photon sensor arrays are essential for medical science, imaging and functional systems. Here, we demonstrate a pressure sensitive UV photodetector array consisting of 32 × 40 pixels based on vertically aligned ZnO nanowires. Each pixel is composed of ZnO nanowire and Au nanopatterns to form a Schottky contact UV photodetector with spatial resolution of 100μm (254 dpi) and response time of 60 ms. The imaging of optical stimuli distributions is achieved by recording the electrical outputs from all pixels of the devices. By utilizing the strain-induced piezoelectric polarization charges at the local Schottky contact, the piezo-phototronic effect has been introduced to modify the energy band diagram and thus to tune/control the generation, recombination, separation and transport of charge carriers during the optoelectronic processes within the UV photodetectors. As a result, the performances of the devices are enhanced by 700% in photoresponsivity, 600% in sensitivity and 280% in detection limit by applying a static strain of 40.83 MPa. This work provides a practical solution to achieving large-scale PDs with high performances by integrating nanowire-photodetector into array configuration. The UV photodetectors array may find applications in optoelectronic systems, biomedical diagnostics, adaptive optical computing and communication.
9:00 PM - ES4.6.30
A Highly Shape-Adaptive, Stretchable Design Based on Conductive Liquid for Energy Harvesting and Self-Powered Biomechanical Monitoring
Fang Yi 1
1 , Peking University, Beijing China
Show AbstractThe rapid growth of deformable and stretchable electronics calls for a deformable and stretchable power source. We report a scalable approach for energy harvesters and self-powered sensors that can be highly deformable and stretch- able. With conductive liquid contained in a polymer cover, a shape-adaptive triboelectric nanogenerator (saTENG) unit can effectively harvest energy in various working modes. The saTENG can maintain its performance under a strain of as large as 300%. The saTENG is so flexible that it can be conformed to any three-dimensional and curvilinear surface. We demonstrate applications of the saTENG as a wearable power source and self-powered sensor to monitor bio- mechanical motion. A bracelet-like saTENG worn on the wrist can light up more than 80 light-emitting diodes. Owing to the highly scalable manufacturing process, the saTENG can be easily applied for large-area energy harvesting. In addition, the saTENG can be extended to extract energy from mechanical motion using flowing water as the electrode. This approach provides a new prospect for deformable and stretchable power sources, as well as self- powered sensors, and has potential applications in various areas such as robotics, biomechanics, physiology, kinesiology, and entertainment.
9:00 PM - ES4.6.31
Self-Powered Motion Sensor Using Flow-Less CNT Sheet Nanogenerator
Hyelynn Song 1 , Taewoo Kim 1 , Hyeongwook Im 1 , Tae June Kang 2 , Yong Hyup Kim 1
1 , Seoul National University, Seoul Korea (the Republic of), 2 , Inha University, Incheon Korea (the Republic of)
Show AbstractCarbon nanotube (CNT), which has one-dimensional atomic structure, is highly accessible to external stimuli because of its high surface area to volume ratio. Thus, electronic configuration of CNT can be strongly influenced by tiny perturbations. The unique interaction between CNT and its surrounding stimuli has been of particular interest over the past decade. A thorough understanding of the interaction enables to develop a wide range of applications, such electrical bio/chemical sensors and actuators with unrivaled performance. Previous researches proved that CNT can generate electrical energy by converting mechanical energy of fluid into electrical energy. The transfer of momentum from the molecules in flowing fluid to the acoustic phonons in the CNT is induced, which in turn drags free charge carriers in the CNT. The driving of free carriers generates a potential difference along the CNT length, but this phenomenon is only realized in low dimensional nano carbon structures. The ability of generating electrical power can be enhanced in highly aligned structures of nanomaterial along the flow direction because this structural characteristic can decrease scattering of dragged charge carriers.
In this work, we investigated the effect of charge carrier dragging in CNT by using more intuitive way of electrostatic induction. A highly aligned, free-standing structure of CNT sheet is used to enhance the charge dragging effect as well as to minimize peripheral influences from a substrate. Up to hundreds of microvolt can be generated, it is affected by sweeping speed, inter-distance between charged object and nanotube sheet, surface charge and number of nanotube sheet layers.
Simple fabrication method of series connection is the most powerful aspect of continuously drawable nanotube sheet, which is simply completed by one-step winding of CNT sheet on the polyethylene terephthalate (PET)/copper foil/PET laminated substrate. As a practical demonstration of the CNT device, we have demonstrated CNT sheet based self-powered motion sensor for tracing finger movements. Coulombic interaction between finger and free charge carriers in CNT sheet induces efficient charge carrier transfer via electrostatic attractive force. Effective motion sensing for moving direction and speed is possible by detecting its electrical output. Motion sensing and energy harvesting are simultaneously available, thus external power source is not needed because of its ability to providing electrical power by itself.
This fundamental studies has great significance in dry-state energy harvesting using nano carbon material which is quietly distinct from previously reported liquid-based energy harvesting studies. Furthermore, suggested self-powered motion sensor can read finger movements (just like a finger commend in a smart phone), requiring no need of touch panels.
9:00 PM - ES4.6.32
Fabrication of Flexible Si/ZnO Heterojunction on Si Membrane with Enhanced Photodetection Utilizing Piezo-Phototronic Effect
Arijit Sarkar 1 , Ajit Katiyar 2 , Subhrajit Mukherjee 1 , Samit Ray 2
1 Advanced Technology Development Centre, IIT Kharagpur, Kharagpur, W.B, India, 2 Department of Physics, IIT Kharagpur, Kharagpur, W.B, India
Show AbstractSilicon based flexible UV-visible photodetectors can play an important role in optoelectronic applications due to its compatibility with existing CMOS technology and its adaptability where flexibility and agility of the device is required. Here we report the fabrication of n-ZnO/p-Si heterojunction based flexible photodetector sensitive to both UV and visible photons. Around 3 µm thick Si membrane has been fabricated by the alkaline etching method followed by deposition of ZnO thin film (~ 120 nm) by RF sputtering. The fabricated flexible heterojunction exhibits a peak responsivity of 0.20 AW-1 with detectivity of 4.8 × 1011 cm Hz1/2 W-1 at zero applied bias. The flexibility of the Si membrane has been utilized for piezo-phototronic effect in ZnO to improve the performance of the device. Strain induced piezo-potential developed in piezoelectric ZnO film has modulated the transport property of the photo generated carriers thereby positively affecting the device performance. With the gradual increase in the external tensile strain from zero to 0.08%, the photocurrent has found to increase from 5.5 mA to 6.7 mA. The accompanying simulation analysis reveals the piezopotential distribution developed in the ZnO film with the application of stress at the heterojunction.
9:00 PM - ES4.6.33
Ultrasound Driven High Performing Triboelectric Nanogenerator for Biomedical Application
Hong Joon Yoon 1 , Sang-Woo Kim 1 , Hanjun Ryu 1
1 , Sungkyunkwan University, Suwon Korea (the Republic of)
Show AbstractNowadays, mechanical energy harvesting technology is getting remarkable attention as being self-powering electronics ranging wide power consumption spectrum. Until now, there have been extensive researches to harvest a plenty of energy to power electronics and charge storage device. Especially for self-powered implantable medical system, scavenging very limited mechanical energy such as pulse by heart, respiration, circulation, is facing technological bottleneck. Without any breakthrough, mechanical energy harvester would not provide enough power to drive not only medical-related electronics, but supporting storage devices such as capacitor and battery. Here, we demonstrate the use of ultrasound as non-destructive mechanical energy to transmit ultrasonic wave through different liquids and skin, and make vibration inside the body. We show that ultrasound driven vibration is quite enough to induce micrometer scaled displacement of 50 μm thick polymer film and to generate electrical energy by triboelectric effect. Calculated root mean square (RMS) voltage and current values with a device dimension of 3.8 x 3.8 cm2 are 13 V and 450 μA in rat. Furthermore, we utilize this approach to charge Li-ion battery, resulting in charging rate of 52 μC/s. Our results manifest transmitting ultrasound as influential energy generating method in biomedical device research and in-vivo self-powering application.
9:00 PM - ES4.6.35
Graphene Tribotronic Transistors for Tactile Sensing
Usman Khan 1 , Tae-Ho Kim 1 , Sang-Woo Kim 1
1 School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon Korea (the Republic of)
Show AbstractHere, we present graphene tribotronic transistors for tactile sensing applications. The working mechanism of the tribotronic devices is based on a coplanar coupling of a single-electrode-mode triboelectric nanogenerator (S-TENG) and a graphene field effect transistor (GFET). When an external object comes into contact with the friction layer of the S-TENG, charges are produced produced on the surface due to triboelectrification. The triboelectric charges act as a gate bias to the GFET and modulates its current transport. The graphene tribotronic transistors offer an excellent tactile sensing characteristics with a limit of detection of < 1kPa, a sensitivity of ~ 2% kPa-1, a fast response time of ~ 30ms, and a stable operation over thousands of cycles. Furthermore, the devices are transparent and flexible, and can spatially map various tactile stimuli such as movement of a ball, multi finger touch etc. Due to all these unique characteristics, the graphene tribotronic transistors are potentially a strong candidate for e-skins and touch screen technologies.
9:00 PM - ES4.6.36
An Inductor-Free Auto-Power-Management Design Built-In Triboelectric Nanogenerators
Yunlong Zi 1 , Hengyu Guo 1 3 , Jie Wang 1 , Zhong Lin Wang 1 2
1 School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States, 3 Department of Physics, Chongqing University, Chongqing, Chongqing, China, 2 Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, Beijing, China
Show AbstractTriboelectric nanogenerator (TENG) has the output characteristics of high voltage but low current/charge transfer, making its efficiency low in powering most of electronics. To address this problem, power management circuits consisting of coupled inductors or transformers are usually employed. Here we report an inductor-free auto-power-management design based on automatic switches between serial-connected and parallel-connected capacitors in a rationally designed manner, so that the output voltage can be lowered and the output charge is enhanced in proportion. In conjunction to theoretical analysis, a TENG along with proof-of-concept power-management units as automatically driven by the triggering motion for TENG is fabricated, which improves the rate for charging a supercapacitor by 5 times. Compared to previous work, this power-management design shows advantages of capability for harvesting low power/frequency scale energy, high scalability, and light weight, which paves a new approach for achieving high-efficient portable TENG-based self-powered system.
9:00 PM - ES4.6.37
Hybrid Thermoelectric Piezoelectric Generator
David Montgomery 1 , Corey Hewitt 1 , David Carroll 1
1 , Wake Forest University, Winston Salem, North Carolina, United States
Show AbstractThermoelectric and piezoelectric generators have long been seen as incompatible with one another due to their vastly different operating parameters. Low resistance thermoelectric and high capacitance piezoelectric systems when placed in the same energy harvesting circuit actively destroy the performance of each other, even though most target systems give off waste heat and vibrations. This work presents a non-trivial integration of flexible thermoelectric and piezoelectric materials into a new meta-structure that allow for both generators to operate simultaneously. This structure is achieved by replacing the bottom electrode of the piezoelectric generator with an alternating p- and n-type semiconductor electrode that doubles and a thermoelectric. Given this structure the devices can be connected together in to increase power output. An example of a 2 by 2 array of devices is shown to generate 89% of the maximum thermoelectric power, and provide 5.3 times more piezoelectric voltage when compared with a traditional device. The true strength of this device is that it does not rely on the specific materials but on how the device is structured.
Symposium Organizers
Wenzhuo Wu, Purdue University
Christian Falconi, University of Tor Vergata
Rusen Yang, University of Minnesota
Junyi Zhai, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences
ES4.7: Piezotronics—Theoretical Discussions
Session Chairs
Wednesday AM, April 19, 2017
PCC North, 200 Level, Room 229 A
9:00 AM - ES4.7.01
Polar-Toroidal Phase Transformation in Inhomogeneous Nanoscale Ferroelectric Systems—A Novel Strategy for the Design of Energy Conversion Nanodevices
Weijin Chen 1 2 , Shuai Yuan 1 , Ye Ji 1 , Gelei Jiang 1 , Jian Shao 1 , Yue Zheng 1
1 State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou China, 2 Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-sen University, Zhuhai China
Show AbstractIt is well known that ferroelectrics are prospective candidates to develop energy conversion devices due to the coupling between polarization and external mechanical, electrical or thermal fields. For nanoscale ferroelectric systems, depolarization effect becomes important and can lead to toroidal ordering of polarization field. Combining first-principle-derived Effective Hamiltonian simulations and phase field simulations, we investigated the ordering of polarization field of several nanoscale ferroelectric systems, including those with an inhomogeneous composition and those subjected to inhomogeneous external fields. We found that these inhomogeneous ferroelectric systems exhibit rather complex polarization ordering behaviors with the coexistence of polar and toroidal ordering, and particularly, a novel and tunable polar-toroidal phase transformation under external mechanical, electrical or thermal fields. Accompanying with this polar-toroidal phase transformation, there is a large change of polarization and strain. As a result, large eletromechanical and thermomechanical performance can be achieved in these systems. The polar/toroidal phase boundaries may belong to a new kind of morphotropic phase boundary (MPB). The polar-toroidal phase transformation in nanoscale ferroelectric systems should provide us a novel strategy to develop energy conversion nanodevices.
9:15 AM - *ES4.7.02
Engineering of van der Waals Interactions in Layered and Two-Dimensional Materials
Evan Reed 1 , Yao Zhou 1 , Lenson Pellouchoud 1
1 , Stanford University, Stanford, California, United States
Show AbstractUsing a Lifshitz based approach to computing the van der Waals interactions between layers in a layered material, we elucidate the key properties of these materials that determine the nature of the interactions. By considering over 200 types of hetero structures, we find that there is potential to observe both attractive and repulsive types of van der Waals interactions, although repulsive effects are likely to be small in magnitude. We study the potential for dynamic modulation and control of these interactions, which may lead to new types of electromechanical devices.
9:45 AM - ES4.7.03
Enhanced Flexoelectrocity in Transition Metal Oxide Superlattices
Andrew Lubimtsev 1 , Haixuan Xu 1
1 , University of Tennessee, Knoxville, Tennessee, United States
Show AbstractRecent investigations into the flexoelectric effect indicate that the induced polarization can be much larger than predicted by naïve phenomenological models, opening up opportunities for electromechanical devices utilizing materials with centrosymmetric lattices. Furthermore, it has been shown that bulk material properties can be enhanced or quenched as a result of interactions at an interface. Superlattices of correlated oxides have even demonstrated novel physics not present in the bulk constituents. Here we present ab initio calculations of the flexoelectric coefficient in a series of SrTiO3/SrMO3 (M = Ti, Ru, Cr) superlattices, and show that the flexoelectric response is greatly enhanced relative even to BaTiO3, which has the highest currently measured flexoelectric coefficient. We quantitatively analyze the modulation of the electronic and ionic contributions to the flexoelectric response, and establish links between the flexoelectricity and the dielectric function. We demonstrate that the enhancement is not specific to a particular composition, and provide general guidelines for the design of devices using flexoelectric polarization.
10:00 AM - ES4.7.04
Electromechanical Fields in Piezoelectric Semiconductor Nanofibers under an Axial Force
Chunli Zhang 1 , Yixun Luo 1 , Xiaoyuan Wang 1 , Weiqiu Chen 1 , Jiashi Yang 2
1 , Department of Engineering Mechanics, Zhejiang University, Hangzhou China, 2 , University of Nebraska–Lincoln, Lincoln, Nebraska, United States
Show AbstractPiezoelectric semiconductors (PS) nanofibers simultaneously exhibit electromechanical coupling effect and unique electric conductive behavior, and have huge applications in sensors, energy harvesters, piezoelectric field effect transistors. Electromechanical fields and charge carriers in PS nanofibers can be effectively controlled by applying a mechanical force. This contribution present a theoretical analysis on the axial extension of an n-type PS nanofiber under an axial force. There is a nonlinear term, which proportional to the products of the unknown carrier densities and the unknown electric field, in the drift currents of electrons. To simplify the nonlinear problem, we propose a one-dimensional linear model, which is suitable for small axial force and hence small electron concentration perturbation. Simple and analytical expressions for the electromechanical fields and electron concentration in the fiber were obtained. Numerical results show that the behavior of the fields is sensitive to the initial electron concentration and the applied axial force.
10:15 AM - *ES4.7.05
Strain Engineering and Energy Harvesting
Ju Li 1
1 , Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
Show AbstractStrain Engineering uses strain to guide the interaction of materials structures with electrons, photons, etc. and control energy, mass and information flows. The success of Strained Silicon technology today harbingers what Strain Engineering may do for human civilization in the future, with potential breakthroughs for electronics, photonics, ferroics, superconductivity, catalysis, sensing, etc. [MRS Bulletin 39 (2014) 108] In this talk I will show examples of how to utilize inhomogeneous strain fields to perform photovoltaic energy harvesting [Nature Photonics 6 (2012) 866] and mechanical energy harvesting [Nature Communications 7 (2016) 10146].
10:45 AM - ES4.7.06
Computational Modelling of Piezoelectric Nanogenerator and Piezotronic Devices
Yongsheng Leng 1
1 , George Washington University, Washington, District of Columbia, United States
Show AbstractSeveral molecular dynamics (MD) models have been developed to study the interfacial sliding dynamics in piezoelectric nanogenerator in atomic force microscopy and monolayer transition metal dichalcogenides (TMDCs) in contact with metal electrodes. The molecular systems include: (1) a vertical semiconductor ZnO (0001) nanowire supported by a substrate and a Pt (111) metal tip sliding over it, and (2) a triangular MoS2 monolayer in contact with two Au (111) electrodes under a tensile strain less than 5%. We calculate the piezoelectric potential distributions based on MD simulations with classical ionic charges. All the calculated potential values refer to the geometric centers of the unit cells. Some intriguing results related to the metal-semiconductor interfacial properties are discussed, which make contributions towards the understanding of piezotronic effect at the interfaces.
ES4.8: Self-Powered Nanosystems
Session Chairs
Wednesday PM, April 19, 2017
PCC North, 200 Level, Room 229 A
11:30 AM - *ES4.8.01
Self-Powered Flexible Inorganic Electronic Systems
Keon Jae Lee 1
1 , KAIST, Daejeon Korea (the Republic of)
Show AbstractThis seminar introduces three recent progresses that can extend the application of self-powered flexible inorganic electronics. The first part will introduce self-powered flexible piezoelectric energy harvesting technology. Energy harvesting technologies converting external sources (such as vibration and bio-mechanical energy) into electrical energy is recently a highly demanding issue. The high performance flexible thin film nanogenerator was fabricated by transferring the perovskite thin film from bulk substrates for self-powered biomedical devices such as pacemaker and brain stimulation. The second part will introduce flexible electronics including large scale integration (LSI) and high density memory. Flexible memory is an essential part of electronics for data processing, storage, and radio frequency (RF) communication. To fabricate flexible large scale integration and fully functional memory, we integrated flexible single crystal silicon transistors with 0.18 CMOS process and memristor devices. The third part will discuss the flexible GaN/GaAs LED for implantable biomedical applications. Inorganic III-V light emitting diodes (LEDs) have superior characteristics, such as long-term stability, high efficiency, and strong brightness. Our flexible GaN/GaAs thin film LED enable the dramatic extension of not only consumer electronic applications but also the biomedical devices such as biosensor or optogenetics. Finally, we will discuss laser material interaction for flexible and nanomaterial applications. Laser technology is extremely important for future flexible electronics since it can adopt high temperature process on plastics, which is essential for high performance electronics, due to ultra-short pulse duration. (e.g. LTPS process over 1000 °C) We will explore our new exciting results of this field from both material and device perspective.
12:00 PM - ES4.8.02
Nanoconfined γ-Phase Ferroelectric Nylon Nanowire for Energy Harvesting Devices
Yeonsik Choi 1 , Anuja Datta 1 , Yonatan Calahorra 1 , Qingshen Jing 1 , Chess Boughey 1 , Sohini Kar-Narayan 1
1 , University of Cambridge, Cambridge United Kingdom
Show AbstractAmong odd-number Nylons, γ-phase Nylon-11 not only offers satisfactory ferroelectricity with thermal stability but has a high potential as a material for energy harvesting devices, especially for triboelectric nanogenerators (TENG). As an electron donating material, it can maximize the performance of the TENG and extend the range of TENG application. However, the extremely rapid cooling rate needed for γ-phase crystallization and additional electric poling and stretching process required for ferroelectricity has hindered widespread of Nylon-11 as a candidate for the energy materials. Here, we report an approach – gas assisted nano-template (GANT) infiltration method – that allows for a high degree of crystal structure control of nano-confined ferroelectric Nylon-11 nanowires. The GANT method is able to change the nucleation initiation site from bulk surface to nanowire surface based on reverse template infiltration method, controlling the cooling rate using assisted gas. This method allows us to demonstrate highly crystalline and self-poled γ-phase Nylon-11 nanowires without post stretching and poling process. In particular, we fabricated self-poled γ-phase Nylon-11 nanowires based triboelectric nanogenerator having 6 times enhanced power density performance of 1.03 Wm-2 than melt quenched film. The GANT method paves the way for creating advanced energy harvesting devices based on γ-phase Nylon-11 ferroelectric nanowires.
12:15 PM - *ES4.8.03
Flexible Electret and Piezoelectret Generators for Wearable Electronics
Jun Zhou 1
1 , Huazhong University of Science and Technology, Wuhan China
Show AbstractWearable electronics for monitoring physiological and biomechanical signals of human body are key sensors for personalized healthcare. To make the wearable electronics work independently and sustainably, a wearable power source is indispensable. Thus, smart energy harvester that can extract energy from human body motions to run body-worn healthcare sensors is particularly desirable. We demonstrated a flexible electret and piezoelectret generators for converting tiny-scale human mechanical energy into electricity.[1-4] The generators rely on the electrostatic effect, and the electrostatic charges on the electrets ware generated by the corona method. Furthermore, the generators ware demonstrated as a self-powered active sensor for healthcare and human Interactive system.
[1] J. Zhong, Q. Zhong, G. Chen, B. Hu, S. Zhao, X. Li, N. Wu, W. Li, H. Yu, J. Zhou, Surface charge self-recovering electret film for wearable energy conversion in a harsh environment, Energy Environ. Sci. 2016, 9, 3085-3091.
[2] W. Li, N. Wu, J. Zhong, Q. Zhong, S. Zhao, B. Wang, X. Cheng, S. Li, K. Liu, B. Hu, J. Zhou, Theoretical Study of Cellular Piezoelectret Generators, Adv. Funct. Mater. 2016, 26, 1964-1974.
[3] Q. Zhong, J. Zhong, X. Cheng, X. Yao, B. Wang, W. Li, N. Wu, K. Liu, B. Hu and J. Zhou, Paper-Based Active Tactile Sensor Array, Adv. Mater. 2015, 27, 7130-7136.
[4] N. Wu, X. Cheng, Q. Zhong, J. Zhong, W. Li, B. Wang, B. Hu, J. Zhou, Cellular Polypropylene Piezoelectret for Human Body Energy Harvesting and Health Monitoring, Adv. Funct. Mater. 2015, 25, 4788-4794.
12:45 PM - ES4.8.04
Triboelectric Nanogenerators Based on Spring Steel Plates for Practical Applications
Guanlin Liu 1 , Chenguo Hu 1
1 Department of Applied Physics, Chongqing University, Chongqing China
Show AbstractGreat attention has been paid to nanogenerators that harvest energy from ambient environments since they were first reported. However, the structures of TENGs working in the vertical contact-separation mode are somehow monotonous and energy loss cannot be avoided during the working process. In this work, we design four novel TENGs, which are all based on spring steel plates so as to harvest low-velocity rectilinear motion energy and rotation motion energy, enhance energy recycle efficiency and maximize space utilization respectively. The factors that may affect the output performance are also explored and the output performance are greatly improved. Besides, the four TENGs have been successfully applied to a self-powered door monitor, a self-powered flashing clapping palm, a rotating speed, rotational angle sensor and power a commercial calculator, respectively. The creative idea of using spring steel plates in TENGs might lead to a new structure/material design for TENGs.
ES4.9: Piezoelectric Nanogenerators II
Session Chairs
Wednesday PM, April 19, 2017
PCC North, 200 Level, Room 229 A
2:30 PM - *ES4.9.01
High Power Density Energy Harvesting Materials and Systems
Shashank Priya 1
1 , Virginia Tech, Blacksburg, Virginia, United States
Show AbstractNovel material properties open the possibility of developing new components and systems. These new components and systems require sustainable power to operate. This synergy between the materials – energy – smart systems has provided the new paradigm for innovation driving the emergence of efficient and high performance architectures. Some examples illustrating these platforms will be provided in this presentation covering solar, thermal, wind, water flow and vibration energy harvesting. One such platform being the self-powered structural health monitoring and automation control nodes. The vast reduction in the size and power consumption of sensors and CMOS circuitry has opened the opportunity to develop on-board power sources that can replace or extend the life of the batteries. In some applications such as sensors for structural health monitoring in remote locations, geographically inaccessible temperature or humidity sensors, the battery charging or replacement operations can be tedious and expensive. Logically, the emphasis in such cases has been on developing the on-site generators that can transform any available form of energy at the location into electrical energy. Generator design is platform dependent and requires considerable integration efforts. For example – in the case of vibrations, various forms of piezoelectric transducer structures have been fabricated to capture the mechanical energy with high efficiency. At micro-to-nanoscale, the design of transducer becomes challenging as the size reduction is accompanied by enhancement in the resonance frequency. We will review the solution to the problem of low frequency resonant transducer structures and demonstrate novel dual phase harvesters that can capture mechanical energy and magnetic energy at the same time. The dual-phase harvester consisting of a magnetostrictive/ piezoelectric/ magnetostrictive (M/P/M) laminate structure utilizing two mechanisms simultaneously: 1. magnetoelectric (ME) effect, where external magnetic field H can excite longitudinal strain through magnetostricitve phase and transfer to piezoelectric phase; 2. Piezoelectric effect, where induced mechanical vibration can create strain and generate charge. Transition of these structures on the micro/nano scale will be discussed and experimental results in this direction will be provided.
3:00 PM - *ES4.9.02
Zinc Oxide Nanorods for Low Frequency Electrical Energy Harvesters on Flexible Substrates
Magnus Willander 1
1 , Linköping University, Norrköping Sweden
Show AbstractZinc oxide (ZnO) well aligned nanorods (NRs) possessing were synthesized on flexible substrates using the low temperature hydrothermal route. These ZnO NRs were then used in different configurations to demonstrate different low frequency energy piezoelectric harvesting devices. Generally the demonstrated piezoelectric devices were tested under the influence of low frequencies and under different weights. The results show relatively high sensitivity for a frequency as low as 5 Hz and relatively low weights down to 10 g. The first application to be demonstrated is handwriting enabled energy harvesters, where we have managed to design a configuration capable of generating up to 4.8 V from handwriting. We further demonstrate a self-powered an anisotropic direction sensor processed on flexible plastic. We will also show that doping ZnO NRs with impurities like e.g. Ag, will lead to loss of crystal symmetry and hence reduce the output harvested electrical energy. We will also show our first results from wire-less communication of our ZnO NRs piezoelectric harvesters with application for security and surveillance systems. Further nanogenerators based on triboelectric (TE) ZnO NRs has been potentially used to harvest mechanical energy from environment into a useful energy for electronic. Here is this work; we developed a triboelectric nanogenerator (TENG) using ZnO NRs grown hydrothermally on paper substrate. By sliding a two paper substrates (containing a layer of ZnO NRs), an electrostatic charges have been observed as the electrons pass between the two materials. An output voltage of 6 V was obtained.
ES4.10: Piezoelectric Semiconductors for Electronics and Optoelectronics
Session Chairs
Wednesday PM, April 19, 2017
PCC North, 200 Level, Room 229 A
4:30 PM - ES4.10.02
Piezotronic Effect on the Light-Induced Pyroelectric and Photoelectric Performance Based on p-Si/Al2O3/n-ZnO Heterojunction Structure
Haiyang Zou 1 , Xiaogan Li 1 3 , Wenbo Peng 1 , Ruomeng Yu 1 , Zhong Wang 1 2
1 , Georgia Institute of Technology, Atlanta, Georgia, United States, 3 School of Electronic Science and Technology, Dalian University of Technology, Dalian, Liaoning, China, 2 , Beijing Institute of Nanoenergy and Nanosystems, Beijing China
Show AbstractThe pyroelectricity initiated by heat sources has been extensively investigated, but the low response time still limits the efficiency and performance. The light-induced pyroelectricity with ultrafast response time has many promising applications like ultrafast optics, communication systems, computational memories. Here, the p-Si/Al2O3/n-ZnO heterojunction NIR photodetector was fabricated for sensing both the photon and heat of light. The sensor has high performance of fast response (~40 μs), high sensitivity and stable signal with low noise. We utilized the strain-induced piezo-polarization charges in a piezoelectric n-ZnO layer to modulate the photogeneration initiated in p-Si, and optimize both the light-induced pyroelectric and photoelectric performance. The results indicate a promising method to optimize the performances of both pyroelectric and photoelectric, and help to reveal the mechanism details of light-induced pyroelectricity. The piezotronic effect on p-insulator-n structure was also first studied.
4:45 PM - ES4.10.03
Interface Doping of ZnO Nanowires—Band-Edge Emission Enhancement and Phase Coherent Transport
Nan Pan 1 , Siwen Zhao 1 , Yiming Wu 1 , Huaiyi Ding 1 , Chao Ma 1 , Xiaoping Wang 1 , J. G. Hou 1
1 Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei China
Show AbstractZnO nanowire (NW) has become one of the most promising candidates for NW UV photonic and optoelectronic devices. To obtain UV light sources with high performance, one must concurrently endow ZnO NW with highly-efficient band-edge emission and excellent electrical properties. However, this is impossible for ZnO materials prepared by conventional bulk doping. Because excellent electrical properties has to be attained through dopant incorporation to provide free carriers, whereas too much bulk doping will inevitably suppress the band-edge radiative recombination.
To address this challenge, we proposed a new strategy of NW interface doping. Through developing a CVD-ALD-CVD re-growth technique, we produced ZnO NWs with a unique interface doping profile. On one hand, the band-edge emission intensity enhances by at least twenty fold in comparison with the conventional ZnO NWs, both the emission from deep levels and the scattering by phonons are greatly suppressed. On the other hand, the electric conductivity surpasses 105 S/m, at least two orders of magnitude higher than the conventional ZnO NWs. Not only the transition from semiconductor to metal can be easily triggered, the phase coherent transport phenomena of electrons such as weak localization (WL), universal conductance fluctuation (UCF), and quantum interference (AAS periodic oscillation) become also prevailing and controllable. Atomic-resolution STEM reveals a few-nanometer-thick, dopant-rich interface layer sandwiched between the core and shell. According to the experimental observations and further analyses, we proposed the mechanism responsible for all of the outstanding performances.
This NW interface doping strategy is versatile and can circumvent the intrinsic restraints of bulk doping, an intra-NW manipulation and maximization of the excellent electrical and optical properties can be guaranteed, which is important to design and fabricate high-performance NW-based nano-optoelectronic and quantum devices.
5:00 PM - ES4.10.04
Local Enhancements of Piezoelectricity and Ferroelectricity for Geometrically Strain Relieved Functional Microstructures
Linghan Ye 1 , James Steffes 1 , Ryan Keech 2 , Ryan Cordier 1 , Thomas Green 1 , Susan Trolier-McKinstry 2 , Bryan Huey 1
1 , University of Connecticut, Storrs, Connecticut, United States, 2 Materials Research Institute, Pennsylvania State University, State College, Connecticut, United States
Show AbstractTransistors, actuators, switches, and piezotronics all leverage microfabrication to achieve discretely addressable functionalities. As device dimensions shrink, however, edge effects for individual microfabricated structures often play a harmful role. For strained ferroelectrics, on the other hand, enhancements may occur due to geometrical strain relief. Using piezo-force microscopy, this is shown to extend up to 500 nm from the free edge of PMN-PT mesas. A piezo-amplitude 2-3 times that of the continuous constrained film is observed, both in the normal as well as lateral directions. For microstructured PZT, depending on the strain conditions, free edges also are found to influence the coercive field, domain nucleation density, and polarization switching mechanism. Results are reported for structures as small as 100x100x100 nm3. Such investigations are crucial for optimizing miniaturize nanogenerators or piezotronics, as well as envisioning new functionalities leveraging strain-relieved property enhancements.
5:15 PM - ES4.10.05
Tuning the Charge Transportation in TiO2 Photoelectrochemical Systems via Ferroelectric Polarization
Yanhao Yu 1 , Weiguang Yang 2 , Matthew Starr 1 , Xudong Wang 1
1 , University of Wisconsin-Madison, Madison, Wisconsin, United States, 2 Electronic Information Materials, Shanghai University, Shanghai, Shanghai, China
Show AbstractHydrogen production from photoelectrochemical (PEC) water splitting is a promising pathway for solar energy conversion. To achieve efficient and durable solar to hydrogen conversion, PEC photoelectrodes desirably need the following characteristics: effective and broad band light absorption, rapid charge separation, and superior stability. N-type semiconductor oxides, such as titanium dioxide (TiO2), hematite (Fe2O3), bismuth vanadate (BiVO4) and tungsten trioxide (WO3), are popular candidates for constructing robust photoanodes due to their excellent chemical stability. The main drawbacks of these oxides are the limited light absorption and poor charge separation efficiency due to their large band gap and high trapping density. There are two predominant strategies to enhance the separation of electron-hole pairs in photoanodes: reducing the crystal size to the scale of the hole diffusion length; and increasing the carrier conductivity by morphology and crystallography control. Nevertheless, both strategies are restricted by the limit of synthesis procedures.
Permanent electrical polarization induced by ionic displacement (e.g., ferroelectric and piezoelectric potential) has shown great promises in engineering the interfacial band structure and manipulating the charge transfer property of heterostructures. PEC water splitting is an electrochemical system driven by similar energy discontinuity at the electrode/electrolyte interface. One can expect positive (maybe significant) performance gain when ferroelectric polarization is appropriately introduced to such a system. Here, we report a development of ferroelectric-enhanced PEC photoanode on the basis of TiO2/barium titanate (BTO) core/shell nanowire (NW) arrays. Through a one-step hydrothermal process, a uniform, epitaxial, and spontaneously poled BTO layer was created on single crystalline TiO2 NWs. Compared to pristine TiO2 NWs, the 5 nm BTO-coated TiO2 NWs achieved 67% photocurrent density enhancement. By numerically calculating the potential distribution across the TiO2/BTO/electrolyte heterojunctions and systematically investigating the light absorption, charge injection and separation properties of TiO2 and TiO2/BTO NWs, the PEC performance gain was proved to be a result of the increased charge separation efficiency induced by the ferroelectric polarization of the BTO shell. The ferroelectric polarization could be switched by external electric field poling and yielded PEC performance gain or loss based on the direction of the polarization. This study evidences that the piezotronic effect (ferroelectric or piezoelectric potential-induced band structure engineering) holds great promises in improving the performance of PEC photoelectrodes in addition to chemistry and structure optimization.
Reference
Yang, W.*; Yu, Y.*;(*equal contribution) Starr, M. B.; Yin, X.; Li, Z.; Kvit, A.; Wang, S.; Zhao, P.; Wang, X., Nano Lett. 2015, 15, 7574-80.
5:30 PM - ES4.10.06
Piezotronic Effect in Strain-Gated Transistor of a-Axis GaN Nanobelt
Ruomeng Yu 1 , Xingfu Wang 1 , Zhong Lin Wang 1
1 , Georgia Institute of Technology, Atlanta, Georgia, United States
Show AbstractDue to the non-centrosymmetric crystal structures, wurtzite family semiconducting materials possess piezoelectric properties and exhibit polarizations along certain directions upon straining. Utilizing strain-induced piezoelectric polarization charges to modulate the energy band structures and thus to tune/control the transport processes of charge carriers is referred to as the piezotronic effect. Distinct from the previous studies of c-axis GaN nanowires, here we systematically study the piezotronic-effect-induced modifications of energy band structures and the corresponding influence on electronic transport properties of a-axis GaN nanobelts. The physical mechanism is carefully illustrated and further confirmed by theoretical simulations via finite element analysis. The spatial distributions of local carrier concentration and the energy band diagrams of a-axis GaN under various straining conditions are calculated. This work provides a thorough understanding of strain-gated transport properties of a-axis GaN piezotronic transistors and its future applications in semiconductor devices.
ES4.11: Poster Session II: Nanogenerators and Piezotronics
Session Chairs
Thursday AM, April 20, 2017
Sheraton, Third Level, Phoenix Ballroom
9:00 PM - ES4.11.02
Ferromagnetic Nanowires Grown by Template-Assisted Electrodeposition for Printable Magnetoelectric Sensing and Energy Harvesting Devices
Chess Boughey 1 , Michael Smith 1 , Yeonsik Choi 1 , Sohini Kar-Narayan 1
1 Department of Materials Science and Metallurgy, University of Cambridge, Cambridge United Kingdom
Show AbstractStray magnetic fields are prevalent in a variety of inaccessible or dangerous locations. In typical homes, magnetic flux densities can vary between (0.01 - 10) G and can exceed 100 G in industrial locations with heavy electrical machinery1. Low-amplitude ambient vibrations are also ubiquitous and so in combination with these magnetic fields, energy can be harvested from both sources simultaneously using magnetoelectric composite (ME) devices. ME devices convert energy stored in magnetic fields into electrical energy via strain coupling of the ferromagnetic and piezoelectric components i.e. via magnetostriction and the piezoelectric effect. Currently, devices in the literature have output power densities of (2-3) mW Oe-1 cm-3 when magnetic fields are the source of energy2 and can output up to 70 mw Oe-1 cm-3 when both vibrations and magnetic energy is sourced3. A MICAZ wireless sensor node requires 2.8 mW of power and has dimensions 5.8 cm x 3.2 cm x 0.7 cm and so these devices are already suitable for powering some commercially available low-power electronic devices4.
In this work, ferromagnetic nickel nanowires (NWs) were grown via electrodeposition within nanoporous anodized alumina templates and subsequently released from the template and dispersed in a solution of the piezoelectric polymer; polyvinylidene fluoride trifluoroethylene (P(VDF-TrFE)). One device architecture attempted in this work is a fully-printed flexible device where interdigitated electrodes are aerosol jet printed (AJP) using a silver nanoparticle ink on a plastic substrate, followed by deposition of the NW dispersion on top, using the same printing process. Both of these fabrication techniques are low–temperature, fast, simple and scalable techniques. After annealing and poling steps, the ME device has the potential to be used as either a magnetic field sensor or a vibrational / magnetic energy harvesting device or both.
Most ME devices in the literature are based on laminate composites, but these are typically less robust than nanowire-based devices. The latter also benefits from increased surface area per unit volume of the two components in contact, as well as increased sensitivity to vibrations and magnetic field sources.
AJP is a relatively new deposition technique where an aerosol of an ink is generated and a sheath gas is used to focus a jet of the ink onto a substrate. The advantages of this technique compared to ink-jet printing for example, include a wider range of compatible inks, both conductive and dielectric, with a wider range of viscosities. It is also possible to print a variety of nanowire-based inks of other materials such as piezoelectric and thermoelectric amongst others.
1 Horton et al., Power Frequency Magnetic Fields and Public Health, CRC Press, 1995.
2 Lasheras et al., Smart Mater. Struct., vol. 24, p. 65024, 2015.
3 Ryu et al., Energy Environ. Sci., vol. 8, pp. 2402–08, 2015.
4 http://www.memsic.com/wireless-sensor-networks/MPR2400CB, 2016.
9:00 PM - ES4.11.03
A Highly Stretchable Fiber-Based Triboelectric Nanogenerator for Self-Powered Wearable Electronics
Xu He 1 , Yunlong Zi 1 , Hengyu Guo 1 , Zhong Lin Wang 1
1 , Georgia Institute of Technology, Atlanta, Georgia, United States
Show AbstractThe development of flexible and stretchable electronics has attracted intensive attention for their promising applications in next-generation wearable functional devices. However, these stretchable devices that are made in a conventional planar format have largely hindered their development, especially in highly stretchable conditions. Herein we firstly developed a novel type of highly stretchable, fiber-based triboelectric nanogenerators (fiber-like TENG) for power generation. Owing to the advanced structural designs including the fiber-convolving-fiber and the highly stretchable electrodes on elastic silicone fiber, the fiber-like TENG can be operated at stretching mode with high strains up to 70%, exhibiting excellent stability and durability; and has been demonstrated for harvesting energy at a range of low frequency stretching motions from 5 Hz down to 0.5 Hz. The stretching mode can be easily realized by stretch motions and can generate a maximum Voc of 142.8 V and a maximum Qsc of 61 nC per stretching cycle in a single fiber-like TENG. Furthermore, the fiber-like TENG has been demonstrated for a broad range of applications, such as powering a commercial capacitor, a LCD screen, a digital watch/calculator, a temperature/humidity sensor and self-powered acceleration sensor. This work introduces a novel fiber structure into the development of highly stretchable TENGs and verifies its promising applications in both power generation and self-powered sensing.
9:00 PM - ES4.11.04
Stretchable and Multifunctional Graphene E-Skin
Qijun Sun 1 , Jeong Ho Cho 2 , Kilwon Cho 3
1 , Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing China, 2 , Sungkyunkwan Advanced Institute of Nanotechnology, Seoul Korea (the Republic of), 3 , Pohang University of Science and Technology (POSTECH), Pohang Korea (the Republic of)
Show AbstractGraphene, a 2D hybridized carbon layer with a hexagonal honeycomb lattice, has attracted attention for its utility in a variety of electronic device applications. Its unique charge transport allows a high carrier concentration (1013cm-2) with a mobility exceeding 104cm2V–1s–1 under ambient condition. Excellent mechanical properties extend the applicability of graphene to stretchable devices, and a good thermal conductivity enhances heat dissipation in highly integrated circuits. Based on high-quality large-area graphene produced through chemical vapor deposition, we developed stretchable and multifunctional graphene E-skin. Firstly, we fabricate a transparent graphene field effect transistor (GFET) pressure sensor matrix (4× 4 pixels) mounted on a plastic or rubber substrate for e-skin applications. The coplanar gate geometry of the GFETs based only on two materials (graphene and ion gel gate dielectric) was highly transparent, displayed a low power consumption, and could be fabricated through a simple process. Secondly, we demonstrate piezopotential-powered active matrix strain sensor arrays using a combination of piezoelectric nanogenerators and coplanar-gate graphene transistors. A coplanar-gate geometry in a graphene transistor simplifies device fabrication by requiring only a two-step photolithography process that takes advantage of the semi-metallic properties of graphene. Thirdly, we develop a transparent and stretchable all-graphene multifunctional E-skin sensor matrix. Three different functional sensors were included in this matrix: humidity, thermal, and pressure sensors, and were judiciously integrated into a layer-by-layer geometry through a simple lamination process. CVD-grown graphene was used to form the electrodes and interconnects for these three sensors, whereas GO and rGO were used as the active sensing materials for the humidity and temperature sensors, respectively. Together, the sensors monitored a variety of daily life sensations with excellent sensitivity. The three sensors in the matrix can also detect external stimuli simultaneously and relay independent electrical signals.
9:00 PM - ES4.11.06
Enhancement of Piezoelectric Performance of a ZnO Nanogenerator by a Combination of Chemical Doping and Interfacial Modification
Yang Zhang 1 , Junyi Zhai 1
1 , Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing China
Show AbstractWe demonstrate a unique strategy to enhance the piezoelectric performance of ZnO-based flexible nanogenerators by chemical doping and interfacial modification. For halogen-doped ZnO nanowire films, dopants and doping concentration dependent lattice strain along the ZnO c-axis are characterized by the EDS, XRD, and HRTEM analysis. Tuning the lattice strain from compressive to tensile state along the ZnO c-axis can be achieved by a substitution of halogen dopant from fluorine to other halogen elements due to the ionic size difference between dopants and oxygen. After preparing a halogen-doped ZnO nanowire film on the p-type CuO film, our results reveal that the piezoelectric performance of the Cl-doped ZnO nanowire film can be further enhanced due to the ability of CuO to reduce the electron screening effect. We demonstrate that the utilization of chemical doping and interfacial modification can be considered as a compatible strategy for realizing a high performance energy-harvesting device.
9:00 PM - ES4.11.07
Single-Thread-Based Wearable and Highly Stretchable Triboelectric Nanogenerators and Their Applications in Cloth-Based Self-Powered Human-Interactive and Sensing
Ying-Chih Lai 1 2 , Steven Zhang 2 , Jianan Deng 2 , Simiao Niu 2 , Hengyu Guo 2 , Zhong Lin Wang 2 3
1 , National Chung Hsing University, Taipei Taiwan, 2 , Georgia Institute of Technology, Atlanta, Georgia, United States, 3 , Beijing Institute of Nanoenergy and Nanosystems, Beijing China
Show AbstractHerein, we presented a new type of single-thread-based triboelectric energy harvester for the first time. The energy-harvesting thread can harvest human-motion energy through contact with skin by using only one thread. With sewing the energy-harvesting thread into a serpentine shape on an elastic textile, a large-area and highly stretchable energy-harvesting textile (SEHT) can be demonstrated. The generating electric output reached up to 200 V and 200 μA. The capability to harvest different kinds of mechanical energy from human body, including the movement of joints, walking, tapping, etc., was demonstrated. The produced electricity was capable to sustainably power a commercial watch, which can advance the development of self-sufficient wearable and biomedical electronics. Additionally, the triboelectric thread can be applied for sensing static and dynamic forces, serving as active sensors. By sewing the triboelectric threads into a glove, a self-powered gesture sensing glove was performed for identifying digital gestures. The triboelectric thread was also demonstrated to act as wearable human-interactive interfaces for transmitting information from touches. Furthermore, a pulse meter was firstly realized by using only one triboelectric thread, opening a door for clothing-based imperceptibly monitoring human physiological signal. By integration with microcontroller systems, a wireless wearable keyboard and smart-bed system were applied for more sophisticated applications. These results show that the newly-designed single thread-based TENG possesses the advantage of interactive, responsive, sewable, and conformal features. The proposed schemes and structures are believed to meet various application needs ranging from wearable and stretchable energy harvesting, thread-based sensing, to biomedical monitoring. The presented methodology is simple, useful, and suitable for mass manufacturing.
9:00 PM - ES4.11.08
High-Performance Triboelectric Nanogenerator (TENG) from Chemically Functionalized Natural Cellulose Materials
Chunhua Yao 1 , Xin Yin 1 , Zhiyong Cai 2 , Xudong Wang 1
1 , University of Wisconsin-Madison, Madison, Wisconsin, United States, 2 , USDA Forest Products Laboratory, Madison, Wisconsin, United States
Show AbstractCellulose, the most abundant natural polymer in nature, is renewable, biodegradable, and cost-competitive. This work reports development of high-performance triboelectric nanogenerator (TENG) with both contacting materials made from cellulosic materials. Cellulose nanofibrils (CNF) was used as raw material, and chemical reaction approaches were employed to attach nitro groups and methyl groups to effectively change the tribo-polarities of CNF, which in turn significantly enhanced the output performance of the TENGs. Specifically, the nitro-CNF possesses a negative surface charge density of 85.8 µCm-2, while the methyl-CNF possesses a positive surface charge density of 62.5 µCm-2, i.e., 0.71 and 0.52 fold of that for fluorinated ethylene propylene (FEP) in magnitude, respectively. The TENG fabricated from nitro-CNF paired with methyl-CNF demonstrated an average voltage output of 8V, and current output of 9 µA. These values are approaching the results from TENG made from FEP. Therefore, this work demonstrated the potential of using environmental-friendly, abundant cellulosic materials for replacing the synthetic polymers in TENGs.
9:00 PM - ES4.11.09
Self-Powered Anti-Biofouling Using Water Wave Energy
Yin Long 1 2 , Yanhao Yu 1 , Xiaobo Chen 1 , Xiaosong Du 2 , Yadong Jiang 2 , Xudong Wang 1
1 Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin, United States, 2 State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu China
Show AbstractThe attachment and accumulation of microorganisms on solid surfaces (e.g., ship’s hulls, underwater pipes, drilling equipments, oil platforms and fishing nets), can cause substantial energy waste and severe damage by increasing fuel consumption, blocking pipes, accelerating metal corrosion, and destroying underwater instrument. Nowadays, prevailing anti-biofouling strategies are focusing on novel coating materials and developing effective electrochemical sterilization procedures. Biofouling process usually starts from the formation of surface double layer, which leads to the absorption of a molecular ‘conditioning’ film containing dissolved organic material for further settlement and nutrition supplies. A promising route for preventing biofilm’s growth is to suppressing or eliminating the evolution of the conditioning film from the initial stage by destroying the double layer formation. Triboelectric nanogenerators (TENGs) have recently shown intriguing capability in producing alternative current electricity by converting mechanical energy impulses. With appropriate design, significant electricity can be produced by harvesting energy from water waves. Here, we demonstrate a self-powered anti-biofouling system by coupling the wave-driven TENG and the anti-fouling electrodes. The triboelectric charges generated by water wave impacts are able to implement dramatic electrostatic force to influence the formation of electrochemical double layer. Consequently, the absorption of biomolecules could be effectively suppressed. A substantial 81% decrease of microorganisms was observed in between the electrodes. Electric field decreases as the electrode distance increases and thus the antifouling effect weakens. Using TENG-based anti-biofouling strategy present a facile, cost effective and scalable approach that prevents first stage attachment of microorganism, demonstrating great promises for underwater infrastructure protection.
9:00 PM - ES4.11.10
Solar Cell-Raindrop TENG Hybrid Devices for Energy Harvesting
Ruiyuan Liu 1 2 , Baoquan Sun 1 , Zhong Lin Wang 2
1 , Soochow University, Suzhou China, 2 Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
Show AbstractSustainable energy harvesting techniques have attracted great attention in nowadays. Among those techniques, solar cell is one of the most widely used devices to capture clean energy. However, power conversion efficiency of solar cell is seriously affected by weather conditions such as in raindays and and almost negligible in the night.The hybrid cell consists of transparent triboelectric nanogenerator (TENG) and conventional solar cell is thus a popular strategy to ease the problem. But most of the reported TENG on solar cells suffer from unsatisfying transparency of lower than 90% which will result in obviously decline in light induced current in the photovoltaic devices. We demonstrate here a highly transparent PDMS layer (T > 96.4%) can serve as both the tribo-electrification layer of the TENG and the encapsulation layer of the solar cell. The highly transparent TENG shows an output voltage of 5 V and 500 nA, respectively, with a maximum output power of 2.5 mW/m2. And the solar cell can maintain its initial efficiency of up tp 95% after the fabrication of the TENG on top of it, which is the best one in all the reported results.
9:00 PM - ES4.11.11
A Nanopillar Arrayed Triboelectric Nanogenerator as a Self-Powered Sensitive Sensor for a Sleep Monitoring System
Weixing Song 1 , Chunwen Sun 1 , Zhong Lin Wang 1 2
1 , Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, Beijing, China, 2 , School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
Show AbstractSleep disorder is a major health problem affecting many people. The monitoring devices for sleep disorder generally require bulky battery packs or continuous use of electricity by an electric plug in order to achieve extreme sensitivities. In addition, exactly detecting body movements caused by sleep apnea is extremely difficult with these devices. Thus, a smart sensor that can drive itself without an additional supply source is highly desirable.
Herein, we introduce an effective approach to solving the problem by using a sensitive and self-powered triboelectric nanogenerator (TENG), inspired by the rapid development of TENGs as sensitive sensor devices.1-3 A sensitive TENG based on an aluminum-plastic laminated film (APLF) serving as a self-powered device for body-movement sensing and sleep monitoring.4 The sandwich structured TENG with an entrapped cantilever spring leaf rapidly responds to the extra pressure. The process of pressing from an external movement and release caused by self-recovering due to rebounce leads to a triboelectric effect and charge separation between the APLF and the entrapped spring leaf. The open-circuit voltage generated from the structured APLF with nanopillars in a uniform diameter of 600 nm and a length of 1.5 μm has more than doubled to 55 V, so the sensitivity of the TENG is significantly improved. The sensitive and flexible TENG based on nanopillar arrays on APLF is easily packaged and used as a self-powered TES for monitoring over-turning movement of a shoulder and a leg during sleeping. Due to their distinctive advantages of TENG and delicate design of the sensor, this work may offer effective approaches to designing wearable electronic devices and improving their electric output performance, and open the possibility for application in healthcare monitoring. These findings also provide a promising strategy to achieve real-time mobile healthcare services for the management of chronic diseases.
References:
Zi, Y. L.; Niu, S. M.; Wang, J.; Wen, Z.; Tang, W.; Wang, Z. L. Standards and Figure-of-Merits for Quantifying the Performance of Triboelectric Nanogenerators. Nat. Commun. 2015, 6, 8376.
Zhu, G.; Peng, B.; Chen, J.; Jing, Q. S.; Wang, Z. L. Triboelectric Nanogenerators as a New Energy Technology: , Devices, to Applications. Nano Energy 2015, 14, 126-138.
Taghavi, M.; Sadeghi, A.; Mondini, A.; Mazzolai, B.; Beccai, L.; Mattoli, V. Triboelectric Smart Machine Elements and Self-Powered Encoder. Nano Energy 2015, 13, 92-102.
Song, W. X. ; Gan, B. H.; Jiang, T.; Zhang, Y.; Yu, A. F.; Yuan, H. T.; Chen, N.; Sun, C. W.; Wang, Z. L. Nanopillar Arrayed Triboelectric Nanogenerator as a Self-Powered Sensitive Sensor for a Sleep Monitoring System. ACS Nano 2016, 10, 8097-8103.
9:00 PM - ES4.11.13
Wearable Power-Textiles by Integrating Fabric Triboelectric Nanogenerators and Fiber-Shaped Dye-Sensitized Solar Cells
Xiong Pu 1 , Weiguo Hu 1 , Zhong Wang 1 2
1 , Beijing Institute of Nanoenergy and Nanosystems, Beijing China, 2 , Georgia Institute of Technology, Atlanta, Georgia, United States
Show AbstractThe rapid development of smart textiles leads to an increasing demand for flexible and wearable power sources, especially for energy-generating devices that are in the form of textile. In this talk, we present an integrated power textile that combines fabric triboelectric nanogenerators (TENG) and fiber-shaped dye-sensitized solar cells (FDSSCs) for scavenging both the solar energy and the energy from human motions. Sliding-mode TENG fabrics with interdigitated grating structures are fabricated to convert low-frequency human motions into high-frequency current outputs. Optimization of the geometrical structures of the TENG fabrics is made to achieve a peak power density of 3.2 W/m2 at the sliding speed of 0.75 m/s. The 1D FDSSC wire achieves an efficiency of 6% with Jsc of about 10.6 mA/cm2. By connecting FDSSCs and rectified TENG fabrics in parallel, the integrated power textile can charge a lithium ion battery (LIB), forming a self-charging power system. Furthermore, this power textile is demonstrated to be flexible and wearable, making our approach promising for applications in wearable electronics.
9:00 PM - ES4.11.15
Large-Scale Manufacturing of Solution-Processed Tellurium Nanowires for Stretchable and Wearable Piezoelectric Device
Yixiu Wang 1 , Wenzhuo Wu 1 , Shihan Wan 1
1 School of Industrial Engineering, Purdue University, West Lafayatte, Indiana, United States
Show AbstractNanowires made of materials with non-centrosymmetric crystal structure are under investigation for their piezoelectric properties and suitability for next-generation self-powered nanodevices. In this work, we report a systematic study on synthesis of trigonal tellurium nanowires with well-controlled dimensions. After assembling the tellurium nanowires on the stretchable substrates, a stretchable, soft piezoelectric nanogenerator has been developed with the capability to efficiently convert mechanical stimuli into electric power. We revealed the correlation between the piezoelectric outputs from the integrated devices and the diameters of as-produced tellurium nanowires. We further studied the feasibility of using the as-fabricated piezoelectric device for biomedical applications, such as gesture recognition. This work establishes the process-structure-property-performance relationship in the piezoelectric nanogenerator that may pave way for the nanomanufacturing and practical applciationsof piezoelectric nanomaterials.
9:00 PM - ES4.11.16
Application of Triboelectric Nanogenerator on Self-Powered Low-Level Laser Cure System and Biocide-Free Antifouling
Tian Jingjing 1 , Zhou Li 1
1 , Beijing Institute of Nanoenergy and Nanosystems, Beijing China
Show Abstract
Bone remodeling or orthodontic treatment is usually a long-term process. Currently, it is accepted that low-level laser therapy has a positive effect on the speed and quality of this process. Thus, low-level laser enhances the vitality actions of cells, and accelerates regeneration of the damaged tissues. To facilitate the applications of this technology, an attachable or implantable laser cure system is demanded. However, a normal battery would not work in this scenario since it is either too big in volume or uncomfortable for the patients.
Biofouling, is the attachment of bacteria and subsequent formation of biofilm and other plants oranimals on wetted surfaces. It poses huge problems to a wide variety of industries wherever water is present. Specifically, it is one of the most challenging issues in marine industry, causing impacts to shipping, coastal constructions, oil pipelines, and underwater sensors. Extensive research efforts have been conducted to develop non-toxic antifouling strategies. Particularly, the methods that impose surface potential on an electrically conducting surface to prevent biofouling have been previously reported. This type of antifouling method imposes a loop current through two conducting surfaces between which water with microorganisms flows through. This current-enabled method not only requires an additional power supply but also has the risk of electrochemical corrosion as the conducting surfaces are exposed in the water.
Recently, the invention of triboelectric nanogenerator (TENG) has provided an effective approach to convert ambient mechanical energy into electricity. The working principle of the TENG is based on the combination of contact electrification and electrostatic induction. Thus TENG could provide the power that low-level laser therapy and prevent biofouling needs.
Here, we developed a self-powered low-level laser cure system for osteogenesis, which significantly accelerated the mouse embryonic osteoblasts’ proliferation and differentiation. And developed a biocide-free antifouling method on insulating surfaces. Significant anti-adhesion efficiencies of as high as 99.3%, 99.1%, and 96.0% are achieved for Escherichia coli, Staphylococcus aureus, and Nitzschia Sp., respectively.
9:00 PM - ES4.11.17
Self-Powered Large-Scale and Pressure-Sensitive Triboelectric Sensor Matrix for Real-Time Tactile Mapping
Xiandi Wang 1 , Xiaoyi Li 1 , Caofeng Pan 1 , Zhong Wang 1
1 , Beijing Institute of Nanoenergy and Nanosystems, Beijing China
Show AbstractDeveloping techniques for digitalized motion tracking and recognition is an important research area in human-machine interactions, artificial electronic skins, and micro-electromechanical systems. Here, we report a self-powered single-electrode-based triboelectric sensor matrix (TESM) that can accurately track and map two-dimensional tactile sensing. A large-scale, pressure-sensitive, flexible and durable TESM with 16 × 16 pixels based on the triboelectric effect was fabricated for the dynamic and fast detection of single-point and multi-point touching. Using cross-locating technology, a high-resolution cross-type TESM with 32 × 20 pixels was developed for more rapid tactile mapping and simplification of the device structure, which significantly reduces the addressing lines from m × n to m + n. In addition, the object being detected can be made from any commonly used materials or can even be human hands, indicating that this device has widespread potential in tactile sensing and touchpad technology applications.
9:00 PM - ES4.11.18
Versatile Energy Harvesting and Self-Powered Sensors Based on Environment-Friendly Triboelectric Nanogenerators
Wei Xu 1 , Long-Biao Huang 1 , Man-Chung Wong 1 2 , Li Chen 1 2 , Gongxun Bai 1 2 , Jianhua Hao 1 2
1 , Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong China, 2 , The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen China
Show AbstractAs a sustainable power source, Triboelectric nanogenerators (TENGs) have got extensive attention from both academia and industry to solve the growing energy crisis. Herein, a hydrogel-based triboelectric nanogenerator (Hydrogel-TENG) is demonstrated, which presents flexibility, environmental friendliness and recyclability simultaneously by using physical-crosslinking Polyvinyl Alcohol (PVA) hydrogel as substrate materials.1 The dependence of electric outputs on the different parameters, including frozen time, the concentration of PVA and the dimension of standard device, has been systematically investigated. The standard device can generate an open-circuit voltage of 200 V and a short-circuit current of 22.5 μA, respectively. The tube-shaped Hydrogel-TENG can harvest mechanical energy from various human motions such as bending, twisting and stretching. Meanwhile, it can be utilized as self-powered sensors to detect the human motions. In addition, the PVA hydrogel utilized in this study is recyclable to benefit for fabricating the renewable TENG. The open-circuit voltage of renewed hydrogel-TENG can arrive at about 92 % of the pristine voltage. This study paves the way for developing flexible energy sources and self-powered sensors in environmentally friendly way. The research was financially supported by the grants from Research Grants Council of Hong Kong (GRF No. PolyU 153004/14P), PolyU Internal Grant (1-ZVGH), National Natural Science Foundation of China (Grant No. 11474241).
Reference:
1. W. Xu, L. B. Huang, M. C. Wong, L. Chen, G. X. Bai, J. H. Hao, Environmentally Friendly Hydrogel Based Triboelectric Nanogenerators for Versatile Energy Harvesting and Self Powered Sensors. Adv. Energy Mater., 2016, 1601529.
9:00 PM - ES4.11.19
Utilization of Magnetic Assisted Noncontact Triboelectric Nanogenerator for Energy Harvesting
Long-Biao Huang 1 , Wei Xu 1 , Gongxun Bai 1 2 , Man-Chung Wong 1 2 , Zhibin Yang 1 2 , Jianhua Hao 1 2
1 Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong China, 2 , The Hong Kong Polytechnic University Shenzhen Research Institute, Shen Zhen China
Show AbstractEnergy harvesting from solar, wind, water wave and ambient mechanical energy has drawn extensive attentions due to the increased carbon emission from limited fossil fuel in the past decades. Recently, triboelectric nanogenerator (TENG) has been used to harvest the wind energy and blue energy. Herein, a novel strategy of wind and blue energy harvesting based on magnetic-assisted noncontact TENG has been demonstrated.1,2,3 Through the combination of magnetic responsive composite with TENG device, the wind and water forces could be converted into the contact separation action between Al/Ni electrode and PDMS film. The influence of the relevant parameters (contact separation frequency, wind speed and humidity, etc.) on the performances of the fabricated TENG has been systematically investigated. The results show the robust potential of magnetic-assisted noncontact TENG for wind and blue energy harvesting applications. The research was financially supported by the grants from Research Grants Council of Hong Kong (GRF No. PolyU 153004/14P), PolyU Internal Grant (1-ZVGH), National Natural Science Foundation of China (Grant Nos. 11474241).
Reference:
1. L.B. Huang, W. Xu, G. X. Bai, M-C, Wong, Z. Yang, J. Hao, Wind Energy and Blue Energy Harvesting Based on Magnetic Assisted Noncontact Triboelectric Nanogenerator, Nano Energy, 2016, 30, 36-42
2. L.B. Huang, G. Bai, M-C. Wong, Z. Yang, W. Xu, J. Hao, Magnetic-assisted noncontact triboelectric nanogenerator converting mechanical energy into electricity and light emission, Adv. Mater., 2016,28,2744-2751
3. W. Xu, L. B. Huang, G. X. Bai, M. C. Wong, Z. Yang, J. H. Hao, Environmentally Friendly Hydrogel Based Triboelectric Nanogenerators for Versatile Energy Harvesting and Self Powered Sensors. Adv. Energy Mater., 2016, 1601529
9:00 PM - ES4.11.21
Strain Modulation in Graphene/ZnO Schottky Junction for Enhanced Photosensing Performance
Zheng Zhang 1 , Shuo Liu 1 , Yue Zhang 1
1 MSE, University of Science and Technology Beijing, Beijing China
Show AbstractStrain modulation in flexible semiconductor heterojunctions has always been considered as an effective way to modulate the performance of nanodevices. In this work, two types of graphene/ZnO Schottky junction have been constructed. They both show considerable responsivity to the UV illumination. Through utilizing the piezopotential induced by the atoms displacement in ZnO under strain, 17% enhanced photosensing property is achieved in the photovoltage type photosensor while 46% improvement in the photoconductive photosensor. This performance improvement can be ascribed to the Schottky barrier height modification by the strain-induced piezopotential. The enhancement mechanism is different in these two photosensors. In the photovoltage type photosensor, the raised barrier height by negative piezopotential facility the electron-hole pairs separation, resulting in performance enhancement. While in the photoconductive photosensor, the improved photocurrent is due to the lower barrier height by positive piezopotential, promoting the electron injection from ZnO to graphene. An energy band principle as well as a finite element analysis is proposed to understand this phenomenon. Our results provide a facile approach to boost the optoelectronic performance of graphene/ZnO heterostructure, which may be also applied to other Schottky junction based hybrid devices.
References
[1]Y. Zhang, X. Yan, Y. Yang, Y. Huang, Q. Liao, J. Qi, Advanced materials, 2012, 24, 4647.
[2]Z. Zhang, Q. Liao, Y. Yu, X. Wang, Y. Zhang, Nano Energy, 2014, 9, 237.
[3]Q. Yang, X. Guo, W. Wang, Y. Zhang, S. Xu, D. H. Lien, Z. L. Wang, ACS Nano, 2010, 4, 6285.
9:00 PM - ES4.11.22
Sustainable Triboelectric Nanogenerator with Pulsed Output—Converting Rotating Energy via Water Electrification
Taehun Kim 1 , Sangmin Lee 1
1 , Chung-Ang University, Seoul, SE, Korea (the Republic of)
Show AbstractThe recent energy crisis has resulted in numerous energy-harvesting methods receiving significant attention in the past decades. To overcome this crisis, we successfully develop a first-ever rotating water triboelectric nanogenerator (TENG) based on water-electrification and rotating device. The proposed TENG is a fully packaged design composed of arrayed devices and mechanical systems for increased efficiency. To the best of our knowledge, the correlation of fluid motion and electrical voltage output performance using fluid dynamics analysis is demonstrated for the first time. In addition, we propose guidelines for optimum design and operation of a TENG using a non-dimensional factor, which is based on the angular velocity of the cylinder and the area of arrayed devices. In addition, a multiphase fluid flow simulation is introduced to demonstrate fluid dynamic motion and the electrical potential based on instantaneous water motion. The power output of a single unit rotating water TENG is 19.1 μW, which can be increased by connecting multiple TENGs. Furthermore, the device combined with a gear train that can light 30 LEDs instantaneously is introduced to demonstrate the wide applicability of the proposed TENG. In addition, we proposed the possibility of a DC power source for small electronics created by connecting a multiple-patterned water TENG to a rectifier. This simple, compact-design triboelectric-nanogenerator could be applied easily everywhere, and this new type of TENG will be able to improve energy-harvesting methods in the future. Thus, our study supports a simple model where a rotating cylinder is filled with water and can be used effectively to expand new types of energy-harvesting methods.
9:00 PM - ES4.11.23
Self-Powered Stretchable Triboelectric Fiber
Hyeon Jun Sim 1 , Duck Won Lee 1 , Seon Jeong Kim 1
1 , Hanyang University, Seoul, SE, Korea (the Republic of)
Show AbstractKinetic sensing system have enormously attractive attention in past decade in accordance with growing industry with wearable electronics and ubiquitous healthcare. Some kinetic sensing system are based on the resistance, capacitance, electromagnetic interaction, optical sensing, piezoelectric and triboelectric effect. Among the various kinetic sensing system, the triboelectric sensor which is the energy converter from mechanical energy to electrical energy, is studied as self-powered sensor which is sensor without external energy source to operate the sensor due to their advantage of high energy converting efficiency, low cost and sensitivity. Recently, 3 dimension (3D) or 2 dimension (2D) triboelectric sensor is transformed into 1 dimensional (1D) fiber structure to make wearable textile or cloth type energy harvester. However, high stretchability of triboelectric fiber is demanded to satisfy human motion strain. Here, we introduce a new type of high stretchable triboelelctric fiber that is based on Poisson ratio difference between buckled structure of PVDF-TrFE electrospun mat/CNT sheet and silver coated nylon wrapped polyurethane fiber of inner electrode during stretching. We designed the new type stretchable electrode and the stretchable triboelectric fiber showed sensitive and stable performance. Furthermore, our device can woven into textile and the textile detected the displacement of strain, frequency and direction by combined between resistance change and triboelectric performance. This study indicate that the fiber has potential as application in future self-power sensor textile of human motion detecting.
9:00 PM - ES4.11.24
Reversibly Wavelength Tunable Laser Based on Single Band-Gap-Graded Semiconductor Nanowires
Minghua Zhuge 1 , Zongyin Yang 2 , Chenlei Pang 1 , Pengfei Xu 1 , Xu Liu 1 , Haifeng Li 1 , Tawfique Hasan 2 , Qing Yang 1
1 State Key Laboratory of Modern Optical Instrumentation, Department of Optical Engineering, Zhejiang University, Hangzhou China, 2 Cambridge Graphene Centre, University of Cambridge, Cambridge United Kingdom
Show AbstractSemiconductor nanowire (NW) lasers have huge potential applications in a lot of fields such as photonic circuits, biology, medicine and environmental monitoring etc. Wavelength tuning of NW lasers is extremely important for their practical applications and caused a lot of interests in recent years.
Utilizing AEA effect, combined with cutting the NWs step-by-step, continuously wavelength variation reaches up to 40 nm has been obtained on pure CdSe NWs. And in single band-gap-graded CdSSe nanowires, the range of wavelength variation could extend to more than 119 nm. Though this approach enables controlling wavelength in an easy way, the nanowire laser can be only used once as the homemade fiber taper has cut them off and the lasing wavelength can’t reverse to longer direction. Up to now, wavelength reversibly tuning lasers still stay a big challenge.
In this work, A reversibly wavelength tunable laser has been achieved on a single band-gap-graded CdSSe NW by introducing effective scattering points to form new oscillating FP cavity. The emitting laser wavelength of this kind of semiconductor NWs is strictly defined by the narrowest band-gap end rather than the wider band-gap. According to this rule, by the touching between the CdSSe NW and another semiconductor NW, the forming scattering point which scatters enough strongly combines the wide band-gap-end face to emerge the new FP oscillating cavity. The fiber probe sticking with the semiconductor NWs is fixed to the 3D-movable PZT modulator can be micro-manipulated automatically so that the lasing wavelength can be tuned reversibly and automatically over a wide visible range.The lasing wavelength from this new FP cavity is totally defined by the center wavelength of photoluminescence (PL) from the renewed scattering point. The reversibly tuning range of the lasing wavelengths from a single NW could cover more than 40 nm, which is limited by the range of photoluminescence (PL) from the nanowires’ band-gap’s variation. With further optimization of material growth and synthesizing condition, the wavelength tuning range can be expected to extend to more than 100 nm.
This reversibly wavelength tunable laser could be expected to have a big application in next-generation of optics intergraded field, multicolor display, optical communication, and so on.
(1) Lieber, C. M. MRS Bull. 2003, 28, 486−491.
(2) Ma, Y.; Guo, X.; Wu, X.; Dai, L.; Tong, L. Adv. Opt. Photonics2013, 5, 216−273.
(3) Yang, Z.; Xu, J.; Wang, P.; Zhuang, X.; Pan, A.; Tong, L. Nano Lett. 2011, 11, 5085−5089.
(4) Li, J.; Meng, C.; Liu, Y.; Wu, X.; Lu, Y.; Ye, Y.; Dai, L.; Tong, L.; Liu, X.; Yang, Q. Adv. Mater. 2013, 25, 833−837.
(5) Yang, Z.; Wang, D.; Meng, C.; Wu, Z.; Wang, Y.; Ma, Y.; Dai, L.; Liu, X.; Hasan, T.; Liu, X.; Yang, Q. Nano Lett. 2014, 14, 3135-3159.
9:00 PM - ES4.11.25
Factors Affecting the Bulk Photovoltaic Effect in LiNbO3
Nadupalli Shankari 1 2
1 Materials Research and Technology, Luxembourg Institute of Science and Technology, Belvaux, Luxembourg, Luxembourg, 2 Physics, University of Luxembourg, Luxembourg, Luxembourg, Luxembourg
Show AbstractWhen a ferroelectric is homogeneously illuminated with a specific wavelength range, a steady state photo current can be observed, even without any interfaces present in the system. This, so called Bulk photovoltaic effect (BPVE) relies on the non-centrosymmetry of the ferroelectric crystal. Iron doped lithium niobate (Fe: LiNbO3) is a prototypical material for the BPVE. The opto-electronic excitation originates from the donor-dopant center (FeLi) in LiNbO3 to the nearest NbNb5+ small free polaron, stimulating a non-thermalized ballistic transport of charge through the crystal, until it thermalizes in the span of 10-13 s. A model has been proposed [1] for Fe: LiNbO3 on non-isotropic excitation of Fe2+ to NbNb5+. However the contributions of factors that affect the BPVE and electron charge transport mechanism are not entirely understood.
The objective of this talk is to focus on identifying factors that are at the origin of the BPVE, i.e. donor center absorption, focusing more on the contribution of interatomic distances and polaronic charge transport both which are susceptible to mechanical stress. The contribution of the interatomic distances will be explained via stress modulation of BPVE constants which also reflect in the XRD spectra; and the NbNb5+ polaron charge transport will be discussed by understanding the shift of the polaron energy via Raman spectroscopy under uniaxial stress. The mechanism of electron transition probability in Fe:LiNbO3 will further be discussed based on the above results.
[1] O. Schirmer et al., Phys. Rev. B 83, 165106 (2011).
9:00 PM - ES4.11.26
Theoretical Study and Quantification of the Performance of Triboelectric Nanogenerator
Jun Peng 1 , G. Snyder 1
1 Materials Science and Engineering, Northwestern University, Evanston, Illinois, United States
Show AbstractTheoretical models for contact-model triboelectric nanogenerator (i.e., metal-metal, metal-insulator and metal-n type semiconductor) were constructed, and the triboelectric charge density generated during contact electrification were calculated based on these theoretical studies. The real-time output characteristics and the relationship between the optimum external resistance and testing parameters were derived. To quantify the performance of triboelectric nanogenerator, figure-of-merit was composed with respect to materials properties of surface charge density and conductivity (i.e., carrier density and mobility). This study is likely to establish the standards for developing triboelectric nanogenerator towards practical applications and inductrialization.
9:00 PM - ES4.11.29
A Universal Anti-Hacking Interface Based on Integration of a Novel Stretchable Keyboard Cover and Advanced Biometric Recognition
Wenbo Ding 1 , Changsheng Wu 1 , Ruiyuan Liu 1 , Jie Wang 1 , Shengming Li 2 , Zhong Lin Wang 1
1 , Georgia Institute of Technology, Atlanta, Georgia, United States, 2 Mechanical Engineering, Tsinghua University, Beijing China
Show AbstractWith the explosive development of Internet and hacking technology, password reveal has become a severe issue and huge threat to people’s privacy and assets. Unfortunately, in the existing human to machine interfaces, there are no effective ways for continuous authentication throughout the typing. Here, we design a novel anti-hacking interface by incorporating the biometrics hidden in the dynamic keystrokes. First, by utilizing a novel stretchable keyboard cover based on the triboelectric nanogenerator (TENG), many specific biometric features can be captured and recorded, including the typing force, surface roughness and etc. Then, the collected specific biometrics as well as the traditional keystroke dynamics are exploited together to realize continuous authentication with the help of advanced pattern recognition technology. In this paper, the emerging machine learning techniques are adopted, for the first time, to significantly enhance the accuracy of authentication. The prototype of this system has been implemented and can reach at least 80% accuracy with the moderate training. This system can greatly reduce the chance of the fake keystroke logging, even if the passwords are revealed by others, and can be added to any touching or knocking based interfaces as a security enhancement.
9:00 PM - ES4.11.30
The Smart Actuation System Based on Triboelectric Nanogenerator
Xiangyu Chen 1 , Zhong Lin Wang 1
1 Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing China
Show AbstractSelf-powered systems have tremendous applications in the fields of portable/wearable personal electronics, wireless health, remote and mobile environmental sensors. The core element of the self-powered system is a packaged energy harvester that can collect energy from ambient environment to realize various functions. For the last decade, the nanogenerator technique has been considered as one of the most promising techniques to serve as the energy harvester for the self-powered system. Ever since the first report on the triboelectric nanogenerator (TENG) in 2012, the performance of this kind of device has been improved dramatically and the energy conversion efficiency reaches up to 50%–85%. The rapidly development of the efficiency of the TENG makes it possible to drive or control various microelectronic devices and even to drive some micro-mechanical systems.
On the other hand, using dielectric elastomer actuators (DEAs) as artificial muscles for soft robotics or soft electronics has attracted considerable interests in the last decade. The dielectric elastomers have similar mechanical properties as human skin, namely a low elastic modulus and a large strain capability, and their deformation can be actuated and controlled by applying an external electric voltage. However, the driving voltage is usually a few thousand volts, which means the high-voltage power supplier may add extra volume/weight for the practical applications of the device. Alternatively, TENG has a unique advantage is that its output voltage is typically high even its volume is rather small, which can be advantageous for driving the dielectric elastomers.
In this study,by directly applying the output voltage from a single-electrode TENG to the DE films, we have demonstrated a novel self-powered TENG-DEA system to provide controllable and notable actuation motion. The separation motion of a Kapton film with the size of 100 cm2, can induce the expansion strain of 14.5% for the DEA samples (electrode diameter of 0.6 cm). The separation distance of TENG can be used to regulate the deformation, while the system can also work stably within a velocity range from 0.1 cm s-1 to 10 cm s-1. The repeatability and persistence studies of this system suggest that the TENG device can provide reliable and constant driving force to DEA devices. Finally, an intelligent switch and a self-powered clamper based on the TENG-DEA are fabricated to demonstrate the application perspective of this system. The flexibility of the DE materials can also open various possible applications in the field of electronic skin or some other soft electronics devices. Together with the self-powered capability of TENG, this actuation system could also potentially be used as a self-powered soft robotic or driving element in the Micro-Electro-Mechanical System. Plenty of important and novel applications based on this working principle are expected to be explored in the near future.
9:00 PM - ES4.11.32
Harvesting Simultaneous Sliding and Vertical Contact-Separation Motion through Portable Triboelectric Nanogenerator
Jihoon Chung 1 , Sangmin Lee 1
1 , Chung-Ang University, Seoul Korea (the Republic of)
Show AbstractTriboelectric nanogenerator (TENG) is an spotlighted energy harvesting method for potential stand-alone energy harvesting device and power source for portable electronics due to its cost-effectiveness and sustainability. This device generates electrical output through contact electrification which is induced by friction between two dielectrics with triboelectric property. However, TENG had limitations for portable applications due to its required size during contact-separation and sliding motion in previous studies. In this work, we introduce TENG with compact design which can harvest simultaneous sliding and vertical contact-separation motion together when external mechanical input is applied. The combination of sliding and vertical contact-separation motion inside the TENG device generate multiple electrical power peaks in single input. The mechanism of simultaneous sliding and vertical contact-separtion TENG is done by high-speed photography and waveform of output power. In addition, the efficiency of the TENG is improved by analysing the motion and controlling the dimensional parameter of TENG substrate and operating parts. Furthermore, hand-held type TENG is demonstrated for portable applications. The portable type TENG have shown to operate commercial LED array independently. This new design can be easily integrated with portable electronics and is a potential solution for hand-held electric generation for practical use.
9:00 PM - ES4.11.33
Dielectric Design for Enhancement of Triboelectric Nanogenerator via Enhanced Electron Trapping and Storage Effects
Jae Won Lee 1 , Hyejin Cho 1 , Changduk Yang 1 , Jeong Min Baik 1
1 , Ulsan National Institute of Science and Technology, Ulsan Korea (the Republic of)
Show AbstractWidespread energy harvesting, generating self-sufficient power from the surrounding environment, such as wind, solar and geothermal, have attracted increasing attention in the past decade due to the energy crisis and global warming. Generally, mechanical energy converted into electricity, namely, by using electromagnetic, electrostatic, and piezoelectric effects. Most recently, a new type of power generating device, named as triboelectric nanogenerator (TENG) based on triboelectric effects coupled with electrostatic effects have been demonstrated as powerful means of harvesting mechanical energy from living environment. Here, the PDMS-grafted polymer was synthesized by using styrene or pentafluorostyrene to control dielectric properties and work functions. We report a new PDMS graft copolymer based TENG for effective dielectrics, resulting in 2 times higher output voltage and current of 72 V and 75 μA at PDMS-H-Styrene based TENG compared to general PVDF based TENG due to the increase of dielectric constant of negatively charged layer and surface potentials on the triboelectric surfaces. Therefore, grafted copolymer shows a great promise in controlling dielectric properties of negatively charged layer in TENG and tuning the performance of polymer-based triboelectric devices for effective mechanical energy harvesting.
9:00 PM - ES4.11.34
Self-Polarized Polyvinyldifluoride-Trifluoroethylene P(VDF-TrFE) Film for Wide Range Pressure Detection
Kaushik Parida 1 , Venkatswarlu Bhavanasi 1 , Pooi See Lee 1 , Jiangxin Wang 1
1 , Nanyang Technological University, Singapore Singapore
Show AbstractPrecise and wide range pressure detection are extremely important for health monitoring, sensor networks, smart robotics and sports applications. However, most of the dynamic pressure sensors fail to sustain a high sensitivity for a wide-range of pressure. In this work, we fabricated a pressure sensor based on a Polyvinyldifluoride-trifluoroethylene (PVDF-TrFE) film, which can detect a wide-range of pressure (0.05 kPa to 600 kPa) with high sensitivity of 0.104 VkPa-1 (range = 0.05 - 5 kPa), 0.055 VkPa-1 (range = 5 - 60 kPa) and 0.049 VkPa-1 (range = 60 - 600 kPa). The wide range pressure detection can be attributed to piezoelectric polarization and triboelectric surface charges of the polymeric sponge. Considering the wide-range and the sensitivity, the fabricated device shows the best performance compared to that of all the dynamic pressure sensors reported so far. This work also addresses the pivotal problem of saturation pressure in a triboelectric nanogenerator and delineates the fundamental role of surface charge for a piezoelectric polymer when used as a triboelectric nanogenerator. Additionally, the self-polarized polymeric sponge addresses the difficulty of electrically poling porous piezoelectric polymers and eliminate the costly and tedious annealing and poling processes. The wide-range pressure detection was demonstrated in a broad spectrum of applications ranging from simple human touch to heavy object manipulation.
9:00 PM - ES4.11.35
Self-Powered Artificial Electronic Skin for High-Resolution Pressure Sensing
Mingyuan Ma 1 , Qingliang Liao 1 , Yue Zhang 1
1 , University of Science and Technology Beijing, Beijing China
Show AbstractElectronic skin (e-skin) comprises a network of tactile sensors, which has broad application prospects in prosthetics, advanced robotics and continuous health monitoring. Here, a self-powered artificial e-skin is fabricated in a simple and cost-effective method for high-resolution pressure sensing. No external power supply is needed for the e-skin owing to the triboelectric mechanism. The response time of pressure sensing is approximately 68 ms and the sensitivity is 0.055 nA KPa-1. With excellent flexibility, the device can be adhered on most curved surfaces for pressure sensing purposes. The 9 × 9 pixelated e-skin with the pixel resolution as high as 127 is capable of mapping the 2D tactile trajectory of a tip. The resolution can proceed to be improved with the enhancement of the pixel density. Furthermore, the unique construction brings about a significant reduction in the number of the test channels from N2 to 2N, which greatly decreases the measurement costs. This work offers an effective step for e-skin, with superiorities of self-powered, high resolution, simple fabrication and low-cost.
9:00 PM - ES4.11.37
Spring-Assisted Triboelectric Nanogenerator for Efficiently Harvesting Water Wave Energy
Tao Jiang 1 , Yanyan Yao 1 , Zhong Wang 1 2
1 , Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences; National Center for Nanoscience and Technology (NCNST), Beijing China, 2 School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
Show AbstractOcean waves are one of the most abundant energy sources on earth, but harvesting such energy is rather challenging due to various limitations of current technologies. Recently, networks formed by triboelectric nanogenerator (TENG) have been proposed as a promising technology for harvesting water wave energy. In this work, a kind of spring-assisted triboelectric nanogenerator was designed and prepared, in which two acrylic blocks covered by Cu-FEP film and connected by a spring can collide with the Cu electrodes anchored on two internal walls of a box. This TENG structure can serve as a basic unit of the TENG network. The electric outputs was studied and optimized by adjusting the motor acceleration, spring rigidity, and spring length. The results indicate that there exists an optimized spring rigidity or spring length to make the TENG unit produce the highest output performance. Moreover, the connected spring can store the energy and further act on the TENG, leading to more electric signal peaks and generating more electric energy. Therefore, the spring-assisted design can more effectively convert the low-frequency mechanical energy (water wave energy) into electricity. Then a device composed of four TENG units in parallel was fabricated to harvest the water wave energy, and it produces high output, which is dependent on the unit number. The present work could provide an approach to improving the output performance and efficiency of TENGs in harvesting water wave energy toward the dream of large-scale blue energy.
9:00 PM - ES4.11.38
In Vivo Self-Powered Wireless Transmission Using Biocompatible Flexible Energy Harvesters
Dong Hyun Kim 1 , Keon Jae Lee 1
1 , KAIST, Yuseong-gu Korea (the Republic of)
Show AbstractThe possibility of practical using of the biomechanical energy was demonstrated with a flexible single crystal PMN-PZT energy harvester. we demonstrate self-powered wireless data transmission enabled by in vivo biomechanical energy derived from cardiac motions in large animal model, using flexible piezoelectric energy harvester realized by a single-crystalline PMN-PZT. From the contraction and relaxation of a porcine heart, the single-crystalline flexible energy harvester generated open-circuit voltage of 17.8V and short-circuit current of 1.74μA which are higher by 4.45 and 17.4 orders of magnitude than that of previously reported in vivo piezoelectric energy harvesting. The various cell viability test and the histological manners were also performed to show the biocompatibility of PMN-PZT flexible energy harvester, which revealed no sign of biological damage and inflammatory reaction. Finally, we could wirelessly transmit communication data using the self-powered system driven by harvesting porcine heartbeat energy. It was also proved visually by repeatedly switching on and off a light bulb in long distance about 5m without any other power source. This successful self-powered wireless data transmission shows the possibility of powerful application to implantable biomedical devices directly using biomechanical energy.
9:00 PM - ES4.11.39
Self-Powered Hybrid Ionic Microdevices by Flexible Energy Harvester
Daniel Joe 1 , Erik Gabrielsson 2 , Jae Hyun Han 1 , Daniel Simon 2 , Magnus Berggren 2 , Keon Jae Lee 1
1 , KAIST, Daejeon Korea (the Republic of), 2 , Linköping University, Norrköping Sweden
Show AbstractElectrochemical devices based on conjugated polymers such as biosensors and ion transistors have received significant attention in bioelectronic applications. In particular, conjugated polymers have been known to be suitable for integration with biological systems since they can be soft, flexible, biocompatible, and both electronically and ionically conductive. In order for successful demonstration of the integrated bioelectronic systems, in vivo implementation of a battery is essential to supply electric power necessary for each iontronic component. Recently, flexible energy harvesters have emerged as a promising alternative to the batteries as they generate sufficient electrical energy to operate such devices.
In this work, we demonstrate a high-performance flexible piezoelectric energy harvester consisting of a large-area PZT thin film on a plastic substrate to operate self-powered iontronic devices. A 2 μm thick crystalline PZT film on a rigid sapphire substrate, which was annealed at 650 °C in air for 45 minutes, is successfully transferred onto a flexible polyethylene terephthalate (PET) substrate via laser lift-off (LLO) without any structural damages or material degradation. The flexible PZT energy harvesting devices typically generate an open circuit voltage of ~200 V and a short circuit current of ~8 μA transduced from small mechanical deformation. The electrical output produced from slight bending and unbending motions by human hands charge capacitors and turn on more than 200 commercial blue LEDs.
Finally, a self-powered hybrid ionic circuit is implemented with PZT energy harvesters, full-wave bridge rectifiers, energy storage elements, and iontronic devices, such as organic electronic ion pumps (OEIP) and ion bipolar junction transistors (IBJT). During the rectification followed by the energy storage, AC output of the harvester is converted into the DC to charge a 100 μF capacitor up to 5.3 V within ~25 minutes. The stored energy provides electrical current of ~150 nA to the OEIP lasted for ~20 minutes. The self-powered OEIP made of a biocompatible material known as PEDOT:PSS is utilized to precisely deliver acetylcholine (Ach), a neurotransmitter that regulates neuronal cell signaling and controls amyloid reactions, with a rate of ~10 pmol/μC. In addition to the passive components as OEIPs, the stored energy also successfully operates nonlinear components as IBJTs to examine addressability of the substance delivery. With a square wave emitter-base voltage of +/- 1 V, a small ionic base control signal actively modulates a relatively much larger ionic collector output signal.
9:00 PM - ES4.11.40
MoS2 Hybrid Nanocomposites for Flexible Thermoelectric Nanogenerators with Enhanced Performance
Yannan Xie 1 , Zong-Hong Lin 2
1 College of Energy, Xiamen University, Xiamen, Fujian, China, 2 Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu Taiwan
Show AbstractIn this work, MoS2-Graphene and MoS2-Te naocomposites are synthesized by a facile hydrothermal method. The structural properties of the nanocomposites are characterized by X-ray diffraction, Raman spectrometry, and scanning electron microscope. Thermoelectric nanogenerators are fabricated by depositing the nanocomposites onto flexible ITO coated PET substrates and using Ag as top electrodes. The nanocomposite devices show enhanced thermoelectric performance, compared with that based on pure MoS2 nanosheets, which may due to the enhanced electrical conductivity resulting from the graphene acting as charge transfer channel in the composites. This work indicates that MoS2 hybrid nanocomposites are promising thermoelectric materials for harvesting environmental thermal energy.
9:00 PM - ES4.11.41
Triboelectric Energy Harvester with an Ultra-Thin Tribo-Dielectric Layer by Initiated CVD and Investigation of Underlying Physics in the Triboelectricity
Daewon Kim 1 , Eunkyoung Byun 2 , Eun Sang Jung 3
1 Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States, 2 IT&E Materials R&D, LG Chem Research Park, Daejeon Korea (the Republic of), 3 Bioenvironmental Energy, Pusan National University, Miryang Korea (the Republic of)
Show AbstractA thickness effect of a tribo-dielectric layer (TDL) made of ultra-thin polymer in a triboelectric energy harvester (TEH) is experimentally and comprehensively studied. The TDL was deposited by the initiated chemical vapor deposition (i-CVD) method and its thickness was precisely controlled to analyze the thickness effect. The correlation between the thickness of the TDL and the output performance is experimentally determined and analytically understood with the aid of the dynamic contact-separation model. In contrast to the conventional static contact-separation model, in this case the output performance increases as the thickness of the TDL increases owing to the dynamic behavior of the electron, which includes drift and recombination phenomenon in the TDL.
9:00 PM - ES4.11.42
Service Behavior of Tailorable Multifunctional Triboelectric Nanogenerators
Qian Zhang 1 , Qijie Liang 1 , Qingliang Liao 1 , Yue Zhang 1
1 Materials Science and Engineering, University of Science and Technology Beijing, Beijing China
Show AbstractTriboelectric nanogenerators (TENGs) or TENG-based self-charging system harvesting energy from ambient environment is a promising power solution for wearable electronics and other electronics. The stable and highly efficient running remains a key consideration in view of potential complex application environment. In this work, we developed a textile-based multifunctional TENG and studied its service behavior and analyzed the mechanism of performance retention when damaged or cut. As a self-powered human body motion sensor, the T-TENG can work well when it was cut. As an energy harvester, the T-TENG is capable of scavenging mechanical energy from water efficiently even it was cut partly. Besides, by integrating with textile-based supercapacitor (SC), an all textile-based flexible self-charging system was also demonstrated and its service behavior was systematically investigated. The T-TENG took a longer time after removing the damaged part to charge the T-SCs, and the charged T-SCs lightened a blue LED successfully. The investigation on service behavior of T-TENG and flexible TENG-based self-charging system will push forward the development of highly reliable energy system and is a guide for other nanodevices and nanosystems.
9:00 PM - ES4.11.43
PVDF-TrFE Electroactive Polymer Mechanical-to-Electrical Energy Harvesting—Experimental Bimorph Structure
Bill Kaval 1 , Robert Lake 1
1 , Air Force Institute of Technology, Wright Patterson AFB, Ohio, United States
Show AbstractResearch of electrostrictive polymers has generated new opportunities for harvesting energy from the surrounding environment and converting it into usable electrical energy. Electroactive polymer (EAP) research is one of the new opportunities for harvesting energy from the natural environment and converting it into usable electrical energy. Piezoelectric ceramic based energy harvesting devices tend to be unsuitable for low-frequency mechanical excitations such as human movement. Organic polymers are typically softer and more flexible therefore translated electrical energy output is considerably higher under the same mechanical force. In addition, cantilever geometry is one of the most used structures in piezoelectric energy harvesters, especially for mechanical energy harvesting from vibrations. In order to further lower the resonance frequency of the cantilever microstructure, a proof mass can be attached to the free end of the cantilever. Mechanical analysis of an experimental bimorph structure was provided and led to key design rules for post-processing steps to control the performance of the energy harvester. In this work, methods of materials processing and the mechanical to electrical conversion of vibrational energy into usable energy were investigated. Materials such as PVDF-TrFE (polyvinyledenedifluoride-tetrafluoroethylene) copolymer films (1µm thick or less) were evaluated and presented a large relative permittivity and greater piezoelectric β-phase without stretching. Further investigations will be used to identify suitable micro-electro-mechanical systems (MEMs) structures given specific types of low-frequency mechanical excitations (10-100Hz).
Symposium Organizers
Wenzhuo Wu, Purdue University
Christian Falconi, University of Tor Vergata
Rusen Yang, University of Minnesota
Junyi Zhai, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences
ES4.12: Piezoelectric Materials and Devices
Session Chairs
Thursday AM, April 20, 2017
PCC North, 200 Level, Room 229 A
9:00 AM - *ES4.12.01
Flexible Piezoelectrics for Energy Harvesting and Sensing
Massimo De Vittorio 1 2
1 , Center for Biomolecular Nanotechnologies - Istituto Italiano di Tecnologia, Arnesano Italy, 2 Dip. Ing. Innovazione, Università del Salento, Lecce Italy
Show AbstractFlexible piezoelectric technology has a huge potential for harvesting kinetic and mechanical energy from the environment and for advanced and smart sensing, with form factor and compliance impossible with their currently available rigid counterparts.
One of the most interesting application of flexible piezoelectrics is in powering and sensing of remote sensors and IoT nodes in civil and industrial environments, in robotics, automotive, health (e.g. IoHT) and wellness. For real world applications, however, good electric and piezoelectric properties need to be accompanied by effective mechanical properties such as flexibility, compliance, durability, reliability, which are often difficult to be obtained in fully organic and/or polymeric piezoelectric materials.
In this presentation it will be shown a comparison of properties of piezoelectrics with both inorganic, organic and hybrid structure and how their technology and (piezo)electric and mechanical properties affect the application of flexible piezoelectrics in MEMS transducers for both sensing and mechanical energy harvesting.
9:30 AM - ES4.12.02
High Throughput Piezoelectric Discovery
Shyam Dwaraknath 1 , Kristin Persson 1
1 , Lawrence Berkeley National Laboratory, Berkeley, California, United States
Show AbstractDespite prolific use in consumer products, energy efficiency, high tech research, and many other industries, piezoelectric are still dominated by lead based materials, and the overall catalog of known piezoelectrics is very small. We have developed a high throughput screening methodology to identify potential next generation piezoelectrics by first classifying the most promising materials based on structural and chemical motifs. High throughput DFT based workflows are then used to calculate the piezoelectric and elastic tensor for the most promising candidates. Once a suitably predicted candidate is found based on metrics of performance, material cost and classifiers of toxicity, we characterize its synthesizability using thermodynamics, the metastable window for that chemical system, and relative phase stability in heteroepitaxial conditions. All of this is performed within the Materials Project ecosystem which provides tools for the necessary calculations, data management, analyses as well as a convenient interface to present to collaborators.
9:45 AM - *ES4.12.03
Non-Resonant and Low Frequency Piezoelectric Energy Harvesters
Hong Goo Yeo 1 , Xiaokun Ma 1 , Tiancheng Xue 2 , Shad Roundy 2 , Christopher Rahn 1 , Susan Trolier-McKinstry 1
1 , The Pennsylvania State University, University Park, Pennsylvania, United States, 2 , University of Utah, Salt Lake City, Utah, United States
Show AbstractPiezoelectric energy harvesting from human motion, in combination with low power electronic devices, has lately attracted considerable attention for wearable sensors. (001) textured lead zirconate titanate (PZT) thin films on flexible Ni foils are useful in this application because the possess a combination of a high energy harvesting figure of merit with a flexible substrate that facilitates preparation of low frequency harvesters. Using PZT films on Ni foils in a compliant mechanism energy harvester with a resonant frequency of 6 Hz, for a excitation of 0.09 g acceleration, 141 microWatts could be achieved. A power density (normalized to the resonant frequecy) of 617 microWatts/(Hz cm2 g2) was achieved.
Non-resonant harvesters for scavenging energy from human motion have also been designed, fabricated and measured. Power levels during walking of about 40 microWatts have been achieved in wrist-watch-like devices.
10:15 AM - ES4.12.04
Scalable Self-Assembled Diphenylalanine Nanotube Bio-Piezoelectric Energy Harvesters
Ju-Hyuck Lee 1 2 , Kwang Heo 1 2 , Ju Hun Lee 1 2 , Seung-Wuk Lee 1 2
1 , University of California, Berkeley, Berkeley, California, United States, 2 , Lawrence Berkeley National Laboratory, Berkeley, California, United States
Show AbstractPiezoelectric materials are excellent generators of clean energy as they can harvest the ubiquitous vibrational and mechanical forces. Although various inorganic piezoelectric materials are practical for energy generation, their fabrication often requires environmentally harmful components and/or energy intensive conditions. Recently, diphenylalanine (FF) has been reported to form nanotubes with strong piezoelectric property comparable to conventional piezoelectric materials. However, the difficulty of fabricating scalable unidirectionally polarized structures that can translate external mechanical force to electric energy has been a major impediment to the realization of a practical piezoelectric device. We developed large-scale unidirectionally polarized, aligned FF nanotubes and fabricated peptide-based piezoelectric energy harvesters. We first used the meniscus driven self-assembly process to fabricate horizontally aligned FF nanotubes. The FF nanotubes exhibit piezoelectric properties as well as unidirectional polarization. In addition, the asymmetric shapes of the self-assembled FF nanotubes enable them to effectively translate external axial forces into shear deformation to generate electrical energy. The fabricated peptide based piezoelectric energy harvesters can generate voltage, current and power of up to 2.8 V, 37.4 nA and 8.2 nW, respectively, with 42 N of force and power multiple liquid-crystal display panels. These novel peptide-based energy harvesting materials will provide a compatible energy source for biomedical applications in the future.
10:30 AM - *ES4.12.05
Integration of Freestanding Piezoelectric Films in Biosensors and Photodetectors
Wei Wu 1 , Ceyhun Kirimli 5 , Wan Shih 5 , Golam Haider 2 3 4 , Yang-Fang Chen 2 , Wei-Heng Shih 1
1 Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania, United States, 5 School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, Pennsylvania, United States, 2 Physics, National Taiwan University, Taipei Taiwan, 3 , National Tsing-Hua University, Hsinchu Taiwan, 4 , Academia Sinica, Taipei Taiwan
Show AbstractFreestanding piezoelectric films are versatile materials for sensing and optoelectronic devices. The first example is a piezoelectric plate sensor (PEPS) which is a new type of biosensor made of a highly piezoelectric lead magnesium niobate-lead titanate (PMN-PT) freestanding film. Real-time detection of a target analyte is achieved by immersing receptor-coated PEPS in the analyte containing liquid and monitoring the PEPS resonance frequency shift due to the binding of analytes to the receptors on the PEPS surface. PEPS exhibited unprecedented sensitivity in real-time quantification of cells, viruses, proteins, and DNA in various liquid environments including patient’s sera using all-electrical measurements. For example, PEPS was shown to specifically detect KRAS mutant DNA in situ with 60 copies per mL analytical sensitivity in a background of clinically-relevant 1000-fold more wild type in 30 min without DNA isolation, amplification, or labeling.1 The high sensitivity is due to the self-sensitivity-enhancing mechanism of binding-induced crystalline orientation switching of the PMN-PT layer which was borne out by direct X-ray diffraction observation on a PMN-PT surrogate made of the same thickness about 1 cm in length and width. The result indicated that each binding step caused the crystalline orientation of the PMN-PT thin layer to switch from the vertical (002) orientation to the horizontal (200) orientation. As a result, the relative resonance frequency shift, Df/f, was enhanced by more than 1000 times as compared to with no crystalline orientation shift through the change of the lateral Young’s modulus of the PMN-PT layer as a result of the crystalline orientation change.2
The second example is to use a piezoelectric Pb(Zr0.2Ti0.8)O3 (PZT) sheet as a substrate to form an ultrasensitive photodetector over a wide range of illumination power. Here, we combined the transparent and conductive properties of graphene with graphene quantum dot (GQD) to create a composite photodetector on PZT. Under a 325 nm UV light illumination, the device shows sensitivity as high as 4.06 × 109 A W-1, which is 120 times higher than reported sensitivity of the same class of devices.3 The enhancement is attributed to the intrinsic electric field provided by the polarization of the piezoelectric substrate that helped maintain the spatial separation between the photo-generated electrons and holes and increase the hole concentration in the graphene to enhance the photoconduction.
References
Ceyhun E. Kirimli, Wei-Heng Shih, and W. Y. Shih, Analyst, 141, 1421 (2016)
Wei Wu, Wei-Heng Shih, and Wan Y. Shih, Journal of Applied Physics 119, 124512 (2016)
Golam Haider, Prathik Roy, Chia-Wei Chiang, Wei-Chun Tan, Yi-Rou Liou, Huan-Tsung Chang, Chi-Te Liang, Wei-Heng Shih and Yang-Fang Chen, Adv. Funct. Mater. 26, 620–628 (2016)
ES4.13: Piezotronics—2D Materials
Session Chairs
Thursday PM, April 20, 2017
PCC North, 200 Level, Room 229 A
11:30 AM - *ES4.13.01
Coupled Acousto-Optical Phonons in Bulk Semiconductor and 2D PiezoelectricMaterials
Morten Willatzen 1
1 , Technical University of Denmark, Kgs. Lyngby Denmark
Show AbstractInteraction of electrons with optical and acoustic phonons governs to a large extent dissipation mechanisms
of bulk and 2D structures and determine their mechanical, thermal, and electrical properties. Usually electron-phonon
interactions lead to performance degrading of devices but they may also open up possibilities to tune
device characteristics by virtue of material and geometry design.
Some cases of phonon tuning applications have been demonstrated in the context of population inversion in
piezoelectric InGaAs quantum dot systems [1]. Other recent phenomena where phonon interactions are central
include dissipation mechanisms in 2D-based electronic and optical devices [2]. Determination of phonon fields
and dispersion relations in many of the important semiconductor materials (3D GaAs, GaN, ZnO and 2D MoS2 and
BN) requires a full accountance of crystal anisotropy and inversion-asymmetry effects including piezoelectricity.
We present a self-contained and combined continuum elastic description of the couplings between acoustic
and optical phonons in general piezoelectric materials and then discuss the differences between phonon properties
in hexagonal 2D non-piezoelectric graphene and 2D piezoelectric MoS2 materials.
The simplest example is a cubic piezoelectric slab and it is demonstrated that phonon modes always involve
coupled acoustic and optical fields except when the phonon in-plane wavenumber component vanishes. This
coupling between acoustic and electric fields also implies that acousto-optical phonons cannot exist at the LO
phonon frequency where the dielectric constant vanishes. Finally we show that confined acousto-optical phonon
modes cannot exist at any frequency in a piezoelectric cubic slab. The model analysis is then extended to hexagonal
2D structures. The 2D materials are treated as 3D materials with an atomic-thin dimension perpendicular to the 2D
plane. Near the Γ point it is shown that one predominant acoustic mode displays parabolic dispersion while two
(predominant) acoustic modes display linear dispersion in agreement with density functional theory calculations.
The equation framework is the elastic equations for the appropriate material and the Maxwell-Poisson equation
supplemented by boundary conditions. Upon solving the full set of differential equations and boundary conditions
the lattice displacements ux, uy, uz and the electric potential φ are determined.
References
[1] J. H. Quilter, A. J. Brash, F. Liu, M. Glässl, A. M. Barth, V. M. Axt, A. J. Ramsay, M. S. Skolnick, and A. M. Fox, Phys. Rev. Lett.
114, 137401 (2015).
[2] F. D. Natterer, Y. Zhao, J. Wyrick, Y.-H. Chan, W.-Y. Ruan, M.-Y. Chou, K. Watanabe, T. Taniguchi, N. B. Zhitenev, and J. A.
Stroscio, Phys. Rev. Lett. 114, 245502 (2015).
[3] M. Willatzen and Z. L. Wang, Phys. Rev. B 92, 224101 (2015).
12:00 PM - ES4.13.02
PSS-Induced Sulfur Vacancy Self-Healing for MoS2 Homojunction and Piezotronics
Xiankun Zhang 1 , Zheng Zhang 1 , Yue Zhang 1
1 , University of Science and Technology Beijing, Beijing China
Show AbstractDue to its reduced dimensions, chemical stability, proper direct band gap, highly efficient light absorption and piezoelectricity1,2, two-dimensional (2D) molybdenum disulfide (MoS2) has the potential in developing next-generation flexible, transparent and wearable nanodevices. As an example, many researchers have focused on creating MoS2 homojunction, the fundamental building block of modern electronics. Due to its identical crystal structure and continuous band alignments in the interface, the MoS2 homojunctions display ideal current rectifying behavior and highly efficient photoresponse than those of heterojunctions. In the homojunction construction, it is the key issue to control the carrier concentration and work function in MoS2. However, by utilizing the conventional methods of chemical doping and thermal annealing, the monolayer MoS2 homojunction shows instability and poor performance3,4,5.
Here, a novel homojunction construction strategy is proposed, in which the sulfur vacancies are healed spontaneously by the sulfur adatom clusters on MoS2 surface through a poly(styrenesulfonate) (PSS)-induced hydrogenation process. The electron concentration of the as-healed MoS2 dramatically decreased, leading to work function enhancement up to ~58 meV. This strategy is then employed to fabricate a high performance lateral monolayer MoS2 homojunction, which presents an ideal current rectifying behavior. Distinguished with previous unstable chemical doping, the lattice defects induced local fields are eliminated during the process of the sulfur vacancy self-healing, which largely improve the performance of MoS2 homojunction. These claims are all supported by the experimental results, including X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), Kelvin probe force microscopy (KPFM) and the photodetection performance. Our findings demonstrate a promising strategy in 2D materials electronic structure modulation for the development of the next-generation electronics and optoelectronics. Besides, no sulfur vacancy monolayer MoS2 has less local field introduced by the defects and also will produce the better piezoelectricity effect than the natural monolayer MoS2.
Reference
1. Qi J, et al. Piezoelectric effect in chemical vapour deposition-grown atomic-monolayer triangular molybdenum disulfide piezotronics. Nat. Commun. 6, 7430 (2015).
2. Wu W, et al. Piezoelectricity of single-atomic-layer MoS2 for energy conversion and piezotronics. Nature 514, 470-474 (2014).
3. Li HM, et al. Ultimate thin vertical p-n junction composed of two-dimensional layered molybdenum disulfide. Nat. Commun. 6, 6564 (2015).
4. Choi MS, et al. Lateral MoS2 p-n junction formed by chemical doping for use in high-performance optoelectronics. ACS nano 8, 9332-9340 (2014).
5. Jin Y, Keum DH, An SJ, Kim J, Lee HS, Lee YH. A Van Der Waals Homojunction: Ideal p-n Diode Behavior in MoSe2. Adv. Mater. 27, 5534-5540 (2015).
12:15 PM - *ES4.13.03
Piezoelectric Characterization of Free-Standing, Monolayer TMDC Materials
S Shiva P Nathamgari 1 , Siyan Dong 1 , Ehsan Hosseinian 1 , Horacio Espinosa 1
1 , Northwestern University, Evanston, Illinois, United States
Show AbstractAtomically thin, two dimensional (2D) materials possess exceptional mechanical, optical and electrical properties and have received great attention in the recent past. Compared to their 1D counterparts (like silver nanowires), complex nano-electronic devices are relatively simpler to fabricate using 2D materials – the most extensively studied material being graphene. Graphene has two major limitations for use in next generation nanoelectronics, viz., the lack of a sizeable band gap and piezoelectricity. Recently, a new category of two dimensional materials, namely, transition metal dichalcogenides (TMDC) have been reported to possess a sizeable, direct band gap that makes them ideally suited for electronic applications. Furthermore, density functional theory (DFT) calculations have predicted TMDCs to possess giant piezoelectric coefficients in monolayer form. In the rapidly emerging field named piezotronics, electronic devices such as field-effect transistors, piezoelectric-gated diodes, and sensors are fabricated by using the inner-crystal piezopotential as a gate voltage to tune/control the charge transport behavior. Experimental characterization reports of piezoelectricity in these materials are few and limited to MoS2. Other 2D TMDC materials such as MoSe2 and MoTe2 are predicted to have larger piezoelectric coefficients- for instance, the piezoelectric coefficient of MoTe2 is predicted to be three times greater than that of MoS2.
Here, we report our work on the fabrication and experimental characterization of piezoelectricity in different monolayer TMDCs – viz. MoSe2, MoTe2 and WTe2. Free-standing monolayer TMDCs clamped by Au electrodes were fabricated using a combination of mechanical exfoliation, PMMA/HSQ bilayer e-beam lithography process, electron-beam evaporation and subsequent lift-off. Characterization of the monolayers was performed through a combination of Raman and photoluminescence spectroscopy, while the crystal orientation was determined using Second Harmonic Generation (SHG) microscopy. Piezoelectric characterization of the suspended monolayers has been performed using a dual-laser interferometric setup that makes use of the membrane-like behavior of monolayers. The piezoelectricity-induced change in the pre-stress of monolayers manifests itself as a change in the vibrational frequency of the membrane and allows determination of the piezoelectric coefficient e11. Furthermore, the intrinsic piezoelectricity can be used to modulate the pre-stress and in turn, the coupling strength between the vibrational modes in these monolayers, with potential for application in phononic devices and ultrasensitive mass sensing. The cavity-monolayer architecture of the fabricated devices also allows exploration of interesting opto-mechanical studies such as laser-induced side-band cooling and parametric amplification.
12:45 PM - ES4.13.04
Piezo-Catalytic Effect on the Enhancement of the Ultra-High Degradation Activity in the Dark by Single- and Few-Layers MoS2 Nanoflowers
Jyh Ming Wu 1 , Wei En Chang 1 , Yu Ting Chang 1 , Chih-Kai Chang 1
1 , National Tsing Hua University, Hsinchu Taiwan
Show AbstractPhotocatalysis has been reviewed extensively and studied for more than half a century because of its critical applications in environmental purification and renewable energy conversion. There have been many studies on the enhancement of the degradation activity by impurity doping, heterojunction structure formation,and loading co-catalysts,which attempts to extend their absorbance in the range from ultraviolet (UV) to visible-light. However, one of the most important issues for blocking the commercial applications of the photocatalysis is still the low efficiency of the degradation activityThe single-layer MoS2 has received considerable attention in recent years because of their unusual properties in electronic, optical, photocatalytic, and piezoelectric properties. The pristine MoS2 nanostructures do not show beneficial photocatalytic properties under a UV or visible-light illumination. In this work, the MoS2 nanoflowers (NFs) are discovered for the first time to have a highly efficient piezo-catalyst effect, which can dramatically improve their degradation activity for destructing the organic dyes by imposing an ultrasonic wave in the dark. The piezoresponse force microscopy (PFM) revealed that a significant amount of piezoelectric potential generated on the edge sites of the abundantly single- and few-layer MoS2 NFs. The measured potential created from the MoS2 NFs explained how the ultra-fast degradation rate of the RB dye reaches 40336 ppm L mole-1s-1 (~93% degradation ratio within 60 sec) under the ultrasonic wave in the dark. This is the fastest degradation rate among the reported values, and is the first description of an ultra-high degradation activity through the piezo-catalytic enhancement effect of the MoS2 NFs under the ultrasonic-wave assistance in the dark.
Reference:Jyh Ming Wu, Wei En Chang,Yu Ting Chang , and Chih Kai Chang, Advanced Materials 28, 11(2016).
ES4.14: Piezophototronics II
Session Chairs
Thursday PM, April 20, 2017
PCC North, 200 Level, Room 229 A
2:30 PM - *ES4.14.01
Piezotronic and Piezo-Phototronic Effect in GaN
Weiguo Hu 1 , Zhong Wang 2
1 Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing China, 2 School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
Show AbstractThanks to the adjustable direct bandgap, high electron mobility, and excellent chemical/physical stabilities, III-nitrides exhibits great potentials in the solid-state lighting, display, power device, photovoltaics and so on. Due to a lack of the crystal lattice symmetry, III-nitrides also have the strong piezoelectric property, semiconducting properties and photo excitation properties. Many attempts (for example such as, nonpolar/semi-polar devices) have been done to eliminate or weaken the piezoelectric effect to improve the internal quantum efficiency. Prof. Wang hold that the piezo-potential can be used as a gate to tune/control the carrier generation, transport, separation and/or recombination via external strain, and thus tuning the device performances [1].
Recently, we systematically studied the carrier transportation in polar and nonpolar GaN under various external stress. Our theoretical and experimental results provided a solid evidence for clarifying the difference between piezotronic effect and piezoresistive effect [2]. And then, within the framework of the piezoelectric band engineering, we adopted the various strain to control 2DEG density in AlGaN/GaN heterojunction and studied strain tuned HEMT [3]. In piezo-phototronic effect, with the quantum perturbation theory and constitutive equations, we studied optical excitation in InGaN/GaN quantum well under the various external stress field [4]. This model was further developed to study the carrier dynamic process and was verified with the time-resolved photoluminescence. The piezoelectric field was partly “canceled”, which increased the overlap of wavefunctions to decrease the carrier decay time. This strain compensation mechanism was used to achieve the ultra-high speed visual light communication system. As a result, the maximum speed of a single chip was increased from 54 MHz up to 117 MHz in a blue LED chip under 0.14% compressive strain.
These researches deepen our understanding on carrier’s excitation and transportation under external strain filed, and exhibits potential applications in electronic device, lighting communication, and human-machine interaction.
REFERENCES
1.X. Wang, J. Song, J. Liu, Z. L. Wang, Science 316 (2007), 102
2.Zhenfu Zhao, Xiong Pu, Cangbao Han, Chunhua Du, Linxuan Li, Chunyan Jiang, Weiguo Hu*, Zhong Lin Wang*; ACS Nano; 2015, 9(8):8578-83
3.Xin Huang, Chunhua Du, Yongli Zhou, Chunyan Jiang, Xiong Pu, Wei Liu, Weiguo Hu, Hong Chen, and Zhong Lin Wang, ACS Nano, 2016, DOI: 10.1021/acsnano.6b00417
4.Wang, X., Yu, R., Jiang, C., Hu, W., Wu, W., Ding, Y., Peng, W., Li, S. and Wang, Z. L. Adv. Mater. 2016, 28(33): 7234–7242
3:00 PM - *ES4.14.02
Kilometers-Long Piezoelectric Polymer Nanoribbon Arrays for Sensing and Energy Generation
Mehmet Bayindir 1 , Mehmet Kanik 2 , Mehmet Say 1
1 UNAM, Bilkent University, Ankara, NA, Turkey, 2 , Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
Show AbstractPiezoelectric materials are widely used in modern electronics in the design of smart materials, and especially in the transformation of mechanical energy into an electronic signal. Typical piezoelectric materials used in device production do not inherently display piezoelectric properties, and must be processed through costly and complex fabrication steps prior to use. We demonstrated a novel fabrication route for producing PVDF and PVDF-TrFE micro and nanostructures, which does not require any post processing for obtaining functional piezoelectric structures with superior properties. Required energy for piezoelectric phase transformation is provided during fiber drawing by applied high temperature and stress, which spontaneously triggers molecules in a polar conformation. Our results show that we can obtain record-high piezoelectric coefficient from our PVDF and PVDF-TrFE nanoribbons. Using our polymeric materials, we have already designed a high-sensitivity tapping device and an energy-harvesting mechanism with enough power-generation capacity to run small devices such as pacemakers. In addition, we developed a new generation, transparent, passive matrix artificial skin with 20x20 pixel and a replica of a human palm with 21 pressure nodes and 17 angular motion sensitive points. The devices requires no external power sources and generates the self-requires-energy. Similar to the human skin, the artificial skin can detect temperature changes, shear force, high and low frequency pressure stimulations with different intensities. The artificial palm and electronic skin is promising for developing human-like shape and temperature sensing robots.
3:30 PM - *ES4.14.03
Hybrid Piezoelectric-Semiconductor Quantum Devices
Armando Rastelli 1
1 , Johannes Kepler University Linz, Linz Austria
Show AbstractElastic strain affects the physical properties of practically any material. In semiconductor-based devices, "strain-engineering" is being massively used for enhancing performance, by tailoring specific properties of the involved materials. However, most of the current devices rely only on static strain fields, while device operation relies on variable electromagnetic (EM) fields.
What if we would be able to dynamically reconfigure the strain-state of a device, so as to change its behavior during operation? In this talk I will show how the properties of classical III-V semiconductors, featuring relatively poor piezoelectric properties, can be dramatically modified by integrating them onto actuators made of materials featuring giant piezoelectricity. The potential of hybrid piezoelectric-semiconductor devices will be illustrated by focusing on epitaxial quantum dots (QDs) embedded in semiconductor nanomembranes [1]. In this field, tunable strains allow accomplishing tasks which cannot be tackled by EM fields alone. After discussing the general effects produced by strain on QDs [2], I will present the first wavelength-tunable QD-sources of single photons [3] and of entangled photon pairs [4]. The latter is obtained by moving from a scalar to a tensorial control of strain fields, which is achieved by microstructured piezoelectric actuators [5]. Finally first results towards ultrafast strain control will be illustrated.
References
[1] A. Rastelli et al., Physica Status Solidi (b) 249, 687 (2012)
[2] Y. Huo et al., Nature Physics 10, 46 (2014)
[3] R. Trotta et al., Advanced Materials 24, 2668 (2012); J. Zhang et al., Nano Lett. 13, 5808 (2013)
[4] R. Trotta et al., Nature Communications 7, 10375 (2016)
[5] J. Martín-Sánchez et al., Advanced Optical Materials 4, 682 (2016)
ES4.15: Piezoelectrics—Theory and Technology
Session Chairs
Yongsheng Leng
Junyi Zhai
Thursday PM, April 20, 2017
PCC North, 200 Level, Room 229 A
4:30 PM - *ES4.15.01
The Piezoelectronic Family of Devices, from RF Switches to Fast Low Power Transistors
Glenn Martyna 1
1 , IBM Research, Yorktown Heights, New York, United States
Show AbstractA transduction based family of devices based on a piezoelectrically driven metal insulator transition is described [1]. An input voltage pulse activates a piezoelectric element (PE) which transduces input voltage into an electro-acoustic pulse that in turn drives an insulator to metal transition (IMT) in a piezoresistive element (PR); the transition effectively transduces the electro-acoustic pulse to voltage. Using the known properties of bulk materials, we predict using modeling that the devvice achieves multi-GHz clock speeds with voltages as low as 0.1 V and a large On/Off switching ratio (≈10^4) for digital logic. The switch is compatible with CMOS-style logic. At larger scale the PET is predicted to function effectively as a large-area low voltage device for use in sensor applications and as a RF switch for applications in communications. Given PR materials with a hysteric insulator metal transition, the memory component of the technology is realized.
The performance of our device is enabled by the properties of two materials, a relaxor piezoelectric for the PE and a rare earth chalcogenide piezoresistor for the PR - provided the materials exhibit bulk properties at the nanoscale. Thus it is critical to investigate materials scaling using a combined theoretical/experimental approach. The development of thin film piezoresistive and piezoelectric materials and patterned structures, and associated characterization tools is presented, along with the theoretical models that yield insight into their behavior [2-4]. Integration of these novel materials into 3 evolutionary generations of PET devices, and device characterization, is given [5] to show that a proof of concept has been achieved.
References
1. “High Response Piezoelectric and Piezoresistive Materials for Fast, Low Voltage Switching: Simulation and Theory of Transduction Physics at the Nanometer-Scale”, G.J. Martyna, et al Adv. Mat. 24, 3672 (2012); “The piezoelectronic stress transduction switch for very large-scale integration, low voltage sensor computation, and radio frequency applications”, Appl Phys. Lett. 107, 073505 (2015).
2. “Giant Piezoresistive On/Off Ratios in Rare-Earth Chalcogenide Thin Films Enabling Nanomechanical Switching”, G.J. Martyna et al, Nano Lett. 13, 4650 (2013).
3. “Anisotropic strain in SmSe and SmTe: implications for electronic transport G.J. Martyna et al, Phys. Rev. B. 90, 245124 (2014).
4. “Lateral scaling of PMN-PT thin films for piezoelectric logic”, G.J. Martyna et al J. Appl. Phys. 115, 234106 (2014).
5. “Pathway to the PiezoElectronic Transduction Logic Device”, Nano Lett. 15, 2391 (2015).
5:00 PM - ES4.15.02
Asymmetric Ion Pairing Effect on Triboelectric Power Generation
Hanjun Ryu 1 , Sang-Woo Kim 1
1 , Sungkyunkwan University, Suwon Korea (the Republic of)
Show AbstractMultifunctional sensor nodes distributed in the form of wireless sensor networks (WSNs) can greatly benefit our daily life, in terms of health care, environmental and structural monitoring, safety and security, nanorobotics, etc. Though the capacity of batteries has greatly increased over the years, they have a limited life time therefore, replacement of a huge numbers of batteries can be an almost impossible task. Triboelectric nanogenerators (TENGs) have been introduced for harvesting the abundantly available mechanical energy in the environment for the sustainable, self-powered operation of WSNs. They make an excellent choice for self-powered smart technologies and can adapt well to various mechanical energy types by different modes of operation such as vertical contact-separation mode, lateral sliding mode, single electrode mode and freestanding mode.
The power output of TENGs strongly depends on the selection of the contact materials. For high output, the two contact layers of a TENG should preferably be on opposite sides of the triboelectric series. Due to the highest electron affinity, fluoroplastics such as polytetrafluoroethylene (PTFE) are the most suitable for the negative contact layer for TENGs. On the other hand, though some dielectric materials such as nylon are relatively more positive than metals like gold (Au) and aluminum (Al), metals are the best candidates for the positive contact layer as they have sufficient free electrons to transfer during contact electrification. In addition, various kinds of surface modifications are utilized to enhance the performance of TENGs, but they typically have limited durability.
Here, we introduce a new ionic doping strategy which adding electrolytes with asymmetric ion pairing to polymer contact layers of TENGs in order to enhance their triboelectric property with a stable operation. Indeed, Kelvin probe force microscopy (KPFM) measurements show that an addition of H3PO4, an electrolyte with more cations than anions, to polyvinyl alcohol (PVA) can make it the most negative triboelectric material itself; whereas, an addition of CaCl2, an electrolyte with more anions than cations, to PVA can make it the most positive triboelectric material itself. Due to these unique features, solid polymer electrolytes (SPEs) are promising triboelectric materials for realizing high performance TENGs for self-powered small electronics.
5:15 PM - ES4.15.02.5
Hybrid Monolithic Nanomanufacturing of Liquid-Solid Heterojunction Devices for Self-Powered Smart Skin
Ruoxing Wang 1 , Wenzhuo Wu 1
1 , Purdue University, West Lafayette, Indiana, United States
Show AbstractThe seamless and adaptive interactions between functional devices and their environment (e.g. the human body) are critical for advancing emerging technologies, e.g. wearable devices, consumer electronics, and healthcare. Although non-electrical signals such as mechanical stimuli are inherent in these applications, electrical control of device operation dominates existing technologies. This scheme of operation not only requires a complex integration of heterogeneous components but also lacks a direct interface between the (opto)electronics and the working environment. Moreover, all existing technologies require a power source, which complicates the system design and limits operation schemes.
The state-of-the-art electronics/optoelectronics are based on planar and rigid structures, limiting their integration with three-dimensional soft biological systems. Mechanically deformable devices incorporating confined liquids present an ideal platform for enabling the conformal coverage of electronics on curved and soft surfaces in related applications. However, to date, liquid-based devices have been limited to merely incorporate liquid components as the passive electrodes given the difficulty in the fabrication of liquid-based heterojunctions. The heterogeneous interfaces between functional materials are the central constituents in the state-of-the-art electronics and optoelectronics. Moreover, there is a lack of the fundamental understanding and technological capability of monolithically integrating liquid structures (e.g. electrodes) with functional materials, in particular, the inorganic semiconductors that offer desired electronic and optoelectronic properties in the anticipated applications.
Here, we demonstrate for the first time a versatile platform for the monolithic integration of liquid-solid heterojunction devices through the hybrid manufacturing of self-assembled inorganic semiconductor nanostructures on additively-manufactured liquid electrodes. This presents a significant advancement towards the realization of liquid-solid hybrid functional systems. The device architecture and fabrication scheme we present are generic for different “functional” liquids, enabling devices responsive to various kinds of stimuli. Moreover, owing to the thin structure, this new class of wearable devices are conformable to human skins and can sustainably perform non-invasive physiological functions, e.g. detection of pulses and vocal vibration, by harvesting the operation power from the human body. The fundamental components that carry out the sensing and interfacing functions, e.g. transistor, can also be directly controlled by the environmental stimuli such as mechanical signals. This research is expected to have a positive impact and immediate relevance to many societally pervasive areas, e.g. biomedical monitoring, consumer electronics, and human-machine interface.
5:30 PM - ES4.15.03
Triboelectric Nanogenerators and Power-Boards from Cellulose Nanofibrils and Recycled Materials
Chunhua Yao 1 , Alberto Hernandez 1 , Yanhao Yu 1 , Zhiyong Cai 2 , Xudong Wang 1
1 , University of Wisconsin-Madison, Madison, Wisconsin, United States, 2 , USDA Forest Products Laboratory, Madison, Wisconsin, United States
Show AbstractThis work reports the implementation of renewable, biodegradable, and abundant cellulose nanofibrils (CNFs) in triboelectric nanogenerator (TENG) development. Flexible and transparent CNF thin films are triboelectric positive material with nanoscale surface roughness. They are paired with FEP (fluorinated ethylene propylene) to assemble TENG devices, which exhibit comparable performance to the reported TENG devices built on synthetic polymers. CNF-based TENG is further integrated within a fiberboard made from recycled cardboard fibers using a chemical-free cold pressing method. The fiberboard produces up to ~30 V and ~90 μA electric outputs when subjected to a normal human step. This development shows great promises in creating large-scale and environmentally sustainable triboelectric board for flooring, packaging and supporting infrastructures from CNF and other natural wood-extracted materials.
ES4.16: Poster Session III: Nanogenerators and Piezotronics
Session Chairs
Friday AM, April 21, 2017
Sheraton, Third Level, Phoenix Ballroom
9:00 PM - ES4.16.01
Wireless Autonomous Self-Propelled Flexible Micromotor
Eswaran Murugasen 1 , Jalal Ghilane 1 , Hyacinthe Randriamahazaka 1
1 , Université Paris Diderot - Paris 7, ITODYS CNRS 7086, Paris France
Show AbstractThere is considerable effort devoted to the development of artificial autonomous micro/nanoscale machines by mimicking living systems and using ambient energy. Micro/nanomotors represent a fundamental step toward the realization of these devices. A micro/nanomotor is a device that converts energy into movement and force. For the practical realization of micro/nano devices in which movement is a desirable property for applications such as drug delivery, the chemically powered, autonomous and self-propelled micro/nano devices are highly needed. Among a variety of micro/nanomotors, particular attention has been given to chemically powered micromotors. The self-propulsion is mainly due to the conversion of chemical energy into mechanical force (such as bubble propulsion). The propulsion by an external energy source (energy harvesting) provides possibilities for the application of micromotors in vivo. There are several self-propelled micromotors made up of Pt, Ag and enzymes etc., but they suffer from either economical or environmental point of view.
In this work, we will present a wireless self-propelled flexible micromotor based on nickel deposited on Nafion. The nickel flexible electrode is fabricated by polymer assisted metal deposition process. Onto this flexible electrode, interpenetrated composite networks containing a conductive polymer, polyaniline, and manganese oxide MnO2 layer were deposited electrochemically. We show that in the presence of H2O2 in the medium the micromotor exhibits a self-propulsion process. The self-propulsion results from the bubble generation at the electrode surface due to the chemical and electrochemical reactions between H2O2 and MnO2 layer. Bubble propulsion is due to the decomposition of H2O2 to oxygen in pH-5.5 citrate buffer solution. The oxygen evolution of nickel flexible electrode in H2O2 solution produces enough bubbles on its surface that propels the electrode. The simple and cost effective preparation methods and the movement in pH near to physiological conditions make this system attractive for development of autonomous chemotaxis devices.
9:00 PM - ES4.16.02
A Self-Powered Long-Term Sterilization System Based on Water Driven Triboelectric Nanogenerator
Hongqing Feng 1 , Tian Jingjing 1 , Ling Yan 2 , Han Ouyang 1 , Yiming Jin 1 , Wen Jiang 1 , Hu Li 2 , Guang Zhu 1 , Zhou Li 1 , Zhong Lin Wang 1 3
1 , Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing China, 2 School of Biological Science and Medical Engineering, Beihang University, Beijing China, 3 School of Materials Science and Engineering,, Georgia Institute of Technology,, Atlanta, Georgia, United States
Show AbstractWe provide an effective and self-powered water sterilization system consisting of a wave-driven triboelectric nanogenerator (TENG) and two nanobrush electrodes made of Ag-nanoparticles (Ag-NP) integrated ZnO-nanowires (ZnO-NW). The sterilization efficiency was very high for various organisms including microbes in natural river water. The colony forming units (CFU) were reduced from 106 to 0 within 20 sec of electrical field (EF) treatment for Gram-negative bacteria. In addition, the bacteria annihilation ability was sustained for at least 20 min after withdrawing the EF. The mechanism lay in the synergetic work of electricity and nanomaterials, which not only produced electroporation during EF treatment, but also induced sustained intracellular reactive oxygen species (ROS) to do long-term sterilization after EF application. Meanwhile, the releasing of metal ions was very low, making this approach safe and environment friendly. Our wave-driven hybrid system proves itself as an advantaged solution for practical natural water sterilization with its self-powered ability and superiority in conditions of uncontinuous power supply.
9:00 PM - ES4.16.03
Self-Activated Luminescence Textile through Mechanical Strain and Static by Tribo
Hye-Jeong Park 1 , JeongHwan Lee 1 , Sung Kyun Kim 1 , Sang-Woo Kim 1
1 , Sungkyunkwan University, Suwon Korea (the Republic of)
Show AbstractWearable energy devices have received an increasing attention for a variety of flexible electronic devices such as smart textiles, flexible displays, artificial skin, sensor, and radio frequency identification patches. Though the flexibility has been demonstrated in displays, sensors, and light-emitting diodes, the use of typically rigid and bulky batteries as a power source is a major issue in the progress of the flexible electronics. In order to overcome the challenge, here, we demonstrate a self-activated luminescence textile which does not require any external power source. Mechanoluminescence (ML) is the trapping of the drifting charge carriers in the presence of a piezoelectric field produced by mechanical deformation and metal-doped zinc sulfide (ZnS) is one of the candidate materials for ML. Recently, ZnS microparticles embedded polydimethylsiloxane (PDMS) composite (ZnS:PDMS) was reported as an one of the promising ML structure because it shows high durability and tunability under various mechanical deformations. Here, for the first time, we found that the luminescence can also be generated by triboelectrification of ZnS:PDMS composite independently of mechanical deformation. The triboelectrification causes discontinuous electrostatic field like alternating current of the alternating-current electroluminescence device. Therefore, we designed a self-activated luminescence textile comprised of ZnS:PDMS composite and teflon weaving structure. We successfully demonstrated luminescence from the smart textile by triboelectrification and strain without any external electric power source. The self-activated luminescence textile is a step toward the development of flexible and wearable devices for monitoring the human motion.
9:00 PM - ES4.16.04
High Performance Piezoelectric Power Generation from Atomic-Layered MoS2 via Sulfur Vacancy Passivation
Tae-Ho Kim 1 , Sang-Woo Kim 1
1 Advanced Material Science and Engineering, Sungkyunkwan University, Suwon Korea (the Republic of)
Show AbstractThe piezoelectric characteristic of two-dimentional materials are of great interest as high-performance piezoelectric potential applications. In order to practical applications, CVD based large area monolayer MoS2 is essential. However CVD based MoS2 has the intrinsic defect such as sulfur vacancy during the growth process and those defect plays and important role in screening the peizoelectric potentail. So only small peizoelectric potential induced power output observed from CVD grown MoS2. Here we demonstrate high performance piezoelectric nanogenerator using CVD based MoS2 by additional sulfur treatment process during MoS2 growth. The measured piezoelectric coeffecient (d11) of CVD grown large area monolayer MoS2 is 3.73 pm V-1 using lateral PFM methods, and it generates a peak power density of a 0.8 pW which is 10 times higher than that of as-grown MoS2. Also to improve the reason why additoinal sulfur treated MoS2 shows enhanced piezoelectric characteristics, XPS, PL and KPFM anylysis was performed.
9:00 PM - ES4.16.05
Largely Improving the Robustness and Lifetime of Triboelectric Nanogenerators through Automatic Transition between Contact and Noncontact Working States
Shengming Li 1 2 , Sihong Wang 3 , Zhong Lin Wang 2
1 Department of Mechanical Engineering, Tsinghua University, Beijing, Beijing, China, 2 School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States, 3 , Stanford University, Palo Alto, California, United States
Show AbstractAlthough a triboelectric nanogenerator (TENG) has been developed to be an efficient approach to harvest mechanical energy, its robustness and lifetime are still to be improved through an effective and widely applicable way. Here, we show a rational designing methodology for achieving a significant improvement of the long-term stability of TENGs through automatic transition between contact and noncontact working states. This is realized by structurally creating two opposite forces in the moving part of the TENG, in which the pulling-away force is controlled by external mechanical motions. In this way, TENGs can work in the noncontact state with minimum surface wear and also transit into contact state intermittently to maintain high triboelectric charge density. A wind-driven disk-based TENG and a rotary barrel-based TENG that can realize automatic state transition under different wind speeds and rotation speeds, respectively, have been demonstrated as two examples, in which their robustness has been largely improved through this automatic transition. This methodology will further expand the practical application of TENGs for long-time usage and for harvesting mechanical energies with fluctuating intensities.
9:00 PM - ES4.16.06
Triboelectric Nanogenerator and Its Application in Sensor
Chang Bao Han 1 , Xiaohui Li 1 , Zhong Lin Wang 1
1 , Chinese Academy of Sciences, Beijing China
Show AbstractRecently, triboelectric nanogenerator (TENG)], which can effectively convert different types of mechanical energy from ambient environment into electricity directly, has been successfully explored to fabricate various types of self-powered systems and sensor, including artificial intelligence systems, gas sensor, liquid sensor, temperature sensor, skin sensor, speed sensor, and so on. In this work, we will some progress about TENG with high power and its application in sensor. For example, a 2-D velocity and trajectory tracking sensor (VTTS) was fabricated by an ingenious electrode design based on an array of single-electrode TENGs. When an object moves on a 2-D plane, it can be regarded as a plane rectangular coordinate system and whatever it locates in, as characterized by corresponding coordinates, (x, y). Conversely, provided that we had detected the coordinates of the object in real time, its velocity and trajectory was able to be obtained by X-Y data at the corresponding time. In addition, a bearing-structure based triboelectric nanogenerator (B-TENG) with interdigital-electrodes was developed that can not only collect energy from rotational kinetic energy, but also serve as a self-powered and multifunctional sensor.
9:00 PM - ES4.16.10
Piezostrain-Enhanced Photovoltaic Effects in BiFeO3/La0.7Sr0.3MnO3/PMN-PT Heterostructures
Haiwu Zheng 1
1 , Henan University, Kaifeng China
Show AbstractBiFeO3 (BFO) is a unique multiferroic material that shows interesting but rather weak photovoltaic effect. Here, we report the first integration of Pt/BFO/La0.7Sr0.3MnO3(LSMO) photovoltaic devices on piezoelectric 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-PT) single-crystal substrates and realized a piezo-photovoltaic effects in the BFO/LSMO/PMN-PT heterostructures through in situ dynamical strain engineering. Upon the application of an electric field of +10 kV/cm, an in-plane compressive strain was induced in the PMN-PT via the converse piezoelectric effect, which was effectively transferred to the BFO film through the LSMO, leading to a change in the in-plane strain and bandgap of the BFO film by ~0.12% and ~22 meV, respectively. As a result, the power conversion coefficiency (PCE) h was dramatically enhanced by ~218%, corresponding to a large gauge factor (Dh/h)/dexx~1817. These results demonstrate that the dynamic strain engineering of photovoltaic properties using the converse piezoelectric effect is an effective and unique approach for realizing enhanced PCE of ferroelectric thin film-based photovoltaic devices.
9:00 PM - ES4.16.11
The Output Power Management of Triboelectric Nanogenerator Based on Pulsed Method
Gang Cheng 1
1 , Henan University, Kaifeng China
Show AbstractThe triboelectric nanogenerator (TENG) usually gives a high output voltage but low output current. Also, the output power decreases hugely with lower load resistance. In addition, when the TENG is used directly to charge capacitor or battery, the charging efficiency is extremely low.
Here, we developed a pulsed mode based method to manage the output power of TENG. Using this method, the instantaneous output current and power can largely enhanced. And, several different self-triggered switches have been design to obtain pulsed discharging. Also, the pulsed TENG with multi-layer structure has been developed to decrease output voltage and enhance collected charges. In addition, the pulsed TENG has been combined with an inductor to charge capacitor, and an overall charging efficiency more than 65% has been obtained. The pulsed mode based TENG has promising application in the output power management of TENG.
9:00 PM - ES4.16.12
Asymmetrical Triboelectric Nanogenerator with Controllable Direct Electrostatic Discharge
Zongming Su 1 , Mengdi Han 1 , Haixia Zhang 1 , Liming Miao 1
1 , Peking University, Beijing, Beijing, China
Show AbstractContact electrification, originating more than 2500 years ago, is one of the ubiquitous scientific phenomena in our daily life, such as hair sticks to rubbed balloon and lightening between clouds. The innovative device of TENG can be effectively utilized to convert mechanical energy into electricity or as self-powered active sensor, which has changed the negative attitude of contact electrification. However, ESD phenomenon has neglected in TENG, although it is obvious in contact electrification and normally known as the sparks in atmosphere.
Here, we presents a novel asymmetrical triboelectric nanogenerator (A-TENG) to produce, detect and analyze contact electrification and electrostatic discharge (ESD) in atmosphere. Compared to traditional symmetrical TENG (S-TENG), which easily reaches saturation after several contact-separate cycles in the early beginning, the asymmetrical structures introduce an unstable state into TENG. The contact pairs overcharge a certain region and improve spatial electrical field until air breakdown illustrated by Paschen law. During the air breakdown, the charges on contact pairs conduct to each other by the ionized air channel and a light signal can be detected. The loss of surface charges leads to the abrupt and obvious output decline of TENG.
By continuous contact-release cycles of friction pairs, the contact electrification and ESD phenomena appear alternately, which is named as “ESD transition processes”. Based on their different features of output patterns, ESD transition processes are divided into four parts. In the first part, named as Charge Accumulation Region (CAR), the tribo charges increase continuously with contact-release cycles. No ESD phenomenon appears in this part. The second part, named as Intermittent Discharge Region (IDR), starts from the first ESD phenomenon when the electric field of over-charged region overpasses discharge threshold. The frequency of ESD remains less than 100 times per minute and increases with time. In the third part, which is called Accelerated Discharge Region (ADR), the “double-layer output” feature indicates the rapid increase of the discharging frequency. In the end, the ESD becomes stable in Uniform Discharge Region (UDR), the final region of the ESD processes. The influence of some key factors, such as contact materials, contact pressure, tilted angle and surface morphology, have also been systematically analyzed to control and analyze ESD transition processes. Meanwhile, the necessary premises to produce ESD can also be avoided to improve stability of TENG, which is of great importance in self-powered sensing system.
In conclusion, the asymmetrical structure has proved TENG as a powerful and real-time analytical equipment to explore fundamentals of contact electrification and ESD. Meanwhile, three necessary premises for ESD in TENG can be selectively avoided for the improvement of the stability of TENG.
9:00 PM - ES4.16.13
High Piezoelectric Perovskite-Structured Nanomaterials and Its Applications to Flexible Energy Harvesters
Kwi-Il Park 1
1 , GNTECH, Jinju-si Korea (the Republic of)
Show AbstractEnergy harvesters which can convert electrical energy from vibrational and mechanical energy sources are very promising tools to realize the sustainable energy generation in isolated, inaccessible or indoor environments and even in human body condition. To harvest electrical energy from ambient mechanical energies created by natural sources or from human movements, piezoelectric energy harvesting devices called a nanogenerator (NG) have been proposed and developed by many researchers. Among piezoelectric materials, perovskite-structured ceramic materials have drawn considerable attention due to their excellent inherent ferroelectric and piezoelectric characteristics. Herein, we will describe high-performance and flexible energy harvesting devices fabricated using various fabrication processes with perovskite-structured piezo-ceramic materials such as BaTiO3/PMN-PT nanowires, BCTZ nanoparticles, and BaTiO3 nanotubes.
9:00 PM - ES4.16.14
Stretchable Thin-Film Generator with Dual Working Modes for Body Motion Energy Harvesting
Xuexian Chen 1 , Yu Song 1 , Haotian Chen 1 , Haixia Zhang 1 , Liming Miao 1
1 , Peking University, Beijing China
Show AbstractThe advancement of wearable electronic devices brings increasing demand on power supply. Flexible and sustainable energy source are of urgent demand for solving this problem. TENG is a promising solution for it can sustainably harvest energy from ambient environment. However, present wearable TENGs are not stretchable and with the weakness of low power generation.
We developed a novelty stretchable thin-film generator (TFG) based on electrification for effectively harvesting body motion energy. The TFG has two working modes, the folding mode and the contact-separation mode (C-S mode), under the same circuit connection. Electrospinning PU nanofibers are employed as a component of electrodes, making it not only flexible but also highly stretchable up to 100%. By modifying the two electrodes with different electron affinity materials and integrating it into thin film structure, the device is much more convenient to be attached onto cloth or skin as a wearable energy harvester. Compared with wearable single electrode TENG, the instantaneous peak power density of the two electrode device can be greatly improved to 336.4 μW/cm2.
The device adopts two pieces of conductive AgNWs/CNT/PU nanofibers embedded into flexible PDMS thin film as electrodes. One of the electrode is coated with micro-patterned PDMS as a friction layer and the other is directly used as another friction layer. The two friction layers are in parallel structure and have a large gap of electron affinity ability. When other materials such as cotton cloth, skin and plastic etc. contact with the device, charges with different polarities are generated on the two surfaces and thus driving electrons flow through external circuit. Otherwise, the device can be folded allowing the two friction layers directly contact and generate charges, which enables the device to be mounted on the joint of the body to harvest body motion energy as well.
The stretch ability test shows that the device can be elongated to 100% of its original state after packaging with PDMS while keeping the resistance change within 250 Ω. When working at folding mode, 670 V peak voltage and 29.3 μA current are obtained under the trigger of vibrator at 5Hz. The output instantaneous power achieves maximum of 3.875 mW at the load resistance of 180 MΩ and a 1 μF capacitor can be quickly charged to 10 V in 100s. To demonstrate its application in real situations, the TFG was attached on cloth and joint of arm to harvest different body motion energies. When people touch the cloth or bend the elbow, the TFG can generate peak voltage of 26.1 V and 27.9 V, respectively.
In summary, we have fabricated a wearable and stretchable thin-film generator based on electrification for effectively harvesting body motion energy. The device has versatile and flexible working modes and have the advantage of high power generation.
9:00 PM - ES4.16.15
Ultrasensitive and Multifunctional Tactile Sensor Based on Overhang Structured Electrode
Hak-Jong Choi 1 , Jeong Hwan Lee 2 , Daihong Huh 1 , Soomin Son 1 , Sang-Woo Kim 2 , Heon Lee 1
1 , Korea University, Seoul Korea (the Republic of), 2 , Sungkyunkwan University, Suwon Korea (the Republic of)
Show AbstractSince increased demand for human-machine interactive electronics, tactile sensors to mimic human sensing organ have a lot of attentions due to their diverse applications from electronic skin (E-skin) to health care monitoring system. Many research groups have demonstrated for tactile sensor using various technologies such as capacitive, piezoelectric, resistive, and optical method. Several methods can achieve the performance with high sensitivities that are possible to mimic the tactile sensing of the human skin. In addition, tactile sensing for multiple spatiotemporal tactile stimuli such as pressure, temperature, and vibration is also demonstrated in previous reports. Although there have been several reports on the development of multifunctional e-skins, these approaches typically require the integration of multiple sensors and sophisticated layouts of interconnected line on the substrate.
In this study, we demonstrate the ultrasensitive and multifunctional tactile sensor using Poly(vinylidenefluoride-co-trifluoroethylene) (P(VDF-TrFE)) as active materials for pressure and temperature sensing and overhang structured 3D electrode for improved pressure sensing and roughness sensing. In brief explanation, P(VDF-TrFE) was spin-casted on bottom electrode and baked at certain temperature. Then, intermediate electrode, passivation layer, top electrode were continuously deposited on P(VDF-TrFE) layer. Patterned template for selective electrodeposition was transferred on top-electrode and residual layer was removed using reactive ion etching process. Subsequently, overhang structured Ni electrode was selectively deposited on top electrode and patterned template was removed using chemical etchant. Then, overhang structured 3D electrode was obtain on the substrate. The overhang structured tactile sensor was investigated for their morphology and sensing properties of pressure, temperature, and roughness. Then, we confirm that overhang structured tactile sensor can improve the sensitivity up to 3 times compared to flat tactile sensor due to overhang structure. In addition, pressure, roughness and temperature are easily distinguished for each other. In these results, overhang structured tactile sensor is potentially possible to apply the electronic skin application in near future.
9:00 PM - ES4.16.16
Towards High Power Density Self-Charging Power Cell
Ganesh Kumar Veerasubramani 1 , Nagamalleswara Rao Alluri 2 , Ananthakumar Ramadoss 2 , Saravanakumar Balasubramaniam 1 , Karthikeyan Krishnamoorthy 1 , Sang-Jae Kim 1
1 Mechatronics Engineering, Jeju National University, Jeju, Jeju, Korea (the Republic of), 2 Mechanical Engineering, Jeju National University, Jeju, Jeju, Korea (the Republic of)
Show AbstractThe advent of modern times and increasing demand in the need of global energy due to rapid deterioration of fossil fuels drives the development of alternate energy conversion and storage systems for the progress of mankind including residential, transportation, industry, military and space exploration. Similarly the rapid growth of nanotechnology have enabled device miniaturization and lowered their operating power requirements; this has encouraged the development of self-powered wearable and portable devices. Among the energy harvesting devices, nanogenerator is an effective tool to harvest the low frequency mechanical energy through piezoelectric and tribo-electrification processes. On the other hand, energy storage devices are just as main as energy harvesters in terms of energy technology in modern society. In particular, electrochemical capacitor is one of the most promising alternative energy storage devices to the conventional batteries because of its high power density, longer cyclic stability and fast charging-discharging capability. These technologies enable us to utilize energy to drive electronic devices/systems. Hence, the integration of energy harvesting and storage devices is the ultimate purpose following the rapid growth of devices and technology, which provide a viable solution. We developed a piezoelectric driven self-charging power cell which contains the PVDF-ZnO as energy harvester and separator with MnO2 as both the positive and negative electrodes using polymer gel electrolyte. Based on this strategy, we now utilized the bio-waste derived honeycomb-like porous carbon as an active electrode material with a novel piezoelectric separator to fabricate self-charging power cell. This will be a low-cost and sustainable approach for the development of self-powered systems.
Acknowledgement:
This work was supported by the Jeju Sea Grant College Program 2016 Funded by the Ministry of Oceans and Fisheries (MOF) and by the National Research Foundation of Korea (NRF) funded by the Korea Government GRANT (2016R1A2B2013831).
Keywords: Self-charging, energy storage, energy harvesting, separator, porous carbon
9:00 PM - ES4.16.18
Layered Tungsten Ditelluride and Its Piezoelectric Property
Srinivaas Masimukku 1 , Isung Kuo 2 , Jyh Ming Wu 2
1 Chemical and Material science Engineering, National Tsing Hua University, Hsinchu, Hsinchu, Taiwan, 2 Material Science and Engineering, National Tsing Hua University, Hsinchu, Hsinchu, Taiwan
Show AbstractLayered transition metal dichalcogenides (TMDS) possess enormous attention in the field of catalysis, optoelectronic devices, sensors, and piezotronics owing to its wide range of chemical, electrical and mechanical properties. Numerous efforts have been made to develop nanostructured TMDS in solution-based methods. Here, we successfully synthesized nanostructured WTe2 in solution phase approach. We further characterized WTe2 and evaluated the piezoelectric properties using atomic force microscopy. The layered nanostructured WTe2 exhibited significant piezoresponse which may result due to its non-centrosymmetric structure. The unique piezoelectric property of the layered WTe2 is opening up the new field applications such as low-power consumption devices, ultrasensitive sensors, and piezoelectric nanogenerators.
Reference
Wenzhuo Wu, Lei Wang, Nature, 514, 470-474.
Symposium Organizers
Wenzhuo Wu, Purdue University
Christian Falconi, University of Tor Vergata
Rusen Yang, University of Minnesota
Junyi Zhai, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences
ES4.17: Piezotronics II
Session Chairs
Friday AM, April 21, 2017
PCC North, 200 Level, Room 229 A
9:00 AM - *ES4.17.01
Luminescent Ions in Composites and 2D Layered Semiconductor Nanosheets for Piezophotonics Applications
Jianhua Hao 1 2
1 , Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong China, 2 , The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen China
Show AbstractPiezophotonics is based on a two-way coupling effect between piezoelectricity and photoexcitation properties. The utilization of a broad range of luminescent ions, including lanthanide and transition metals can be considered for a wide variety of applications. In our works, various composite materials have been prepared, which can sense or harvest broad mechanical energy, including stretch, vibration pressure, handwriting and mechanical friction. A new class of luminescence, namely magnetic-induced luminescence (MIL) has firstly been realized in luminescent ions doped composite laminates by coupling magnetic field to piezophotonics. Differing from conventional magnetic sensors, the MIL-based devices enjoy competitive advantages, including real-time visualization, remote sensing without making electric contact, nondestructive and noninvasive detection. Most recently, we further demonstrate full-color emissions through piezophotonic process by dynamical control. On the other hand, the ultimate goal of making atomically thin electronic and optoelectronic devices greatly stimulates the research two-dimensional (2D) materials, such as transition metal dichalcogenides (TMDs). Luminescent ion doped TMDs, such as MoS2 samples are achieved and their structural and optical properties are investigated. The study opens the possibility for realizing novel 2D luminescent device. Our works imply that luminescent ion-doped material can play important roles as a platform for both fundamental studies and potential applications in the research field of piezophotonics. The research was supported by the grants from Research Grants Council of Hong Kong (GRF No. PolyU 153281/16P), NSFC (11474241), and PolyU (4-BCCA and E-RD50).
Reference:
1. G. Bai, M.-K. Tsang, and J. Hao, Adv. Funct. Mater. 26, 6330 (Feature Article) (2016).
2. M.-C. Wong, L. Chen, M.-K. Tsang, Y. Zhang, and J. Hao, Adv. Mater. 27, 4488 (2015).
3. G. Bai, S. Yuan, Y. Zhao, Z. Yang, S. Y. Choi, Y. Chai, S. F. Yu, S. P. Lau, and J. Hao, Adv. Mater., 28, 7472 (2016).
9:30 AM - ES4.17.02
Strontium-Doping Effects in Solution Derived Lead-Free Ferroelectric K0.5Na0.5NbO3 Thin Films
Barbara Malic 1 2 , Katarina Vojisavljevic 1 , Tanja Pecnik 1 , Hana Ursic 1 , Aleksander Matavz 1 2 , Vid Bobnar 1 2
1 , Jozef Stefan Institute, Ljublijana Slovenia, 2 , Jozef Stefan International Postgraduate School, Ljubljana Slovenia
Show AbstractPotassium sodium niobate, K0.5Na0.5NbO3 (KNN) is an environment-friendly lead-free alternative to highly efficient lead-based piezoelectrics. The poor functional properties of the KNN thin films prepared by chemical solution deposition are frequently related to the volatilisation of alkali species during processing, which hinders control over the stoichiometry, contributes to formation of secondary phases and deterioration of the microstructure. The problem can be overcome by adding alkalis in excess and/or by partial substitution of the A- and B- site atoms, such as in the case of the solid state synthesized KNN ceramics. Therefore, in this contribution, the influence of the alkaline-earth A- site dopant, Sr2+ on the microstructure, structure, and functional properties were examined for the solution-derived KNN thin films with alkaline excess.
Liquid precursors of (K0.5Na0.5)1-ySryNbO3 (KNN-ySr) thin-films, where the Sr- dopant content was set at y = 0, 0.005, 0.01, were prepared from potassium and sodium acetates and niobium ethoxide in 2-methoxyethanol solvent with 5 mol% of potassium acetate excess. Strontium was introduced as acetate or nitrate. The approximately 250 nm thick KNN-ySr thin films on Pt/TiOx/SiO2/Si substrates were obtained by rapid thermal annealing at 650 oC.
According to X-ray diffraction analysis, all synthesized KNN thin films crystallize in pure perovskite phase with random orientation. The surface and cross-section microstructure analysis, performed by the field emission scanning electron microscopy, reveals that the KNN-ySr films consist of equiaxed grains, the average size of which gradually decreases from about 90 nm to a few tens of nm by increasing the Sr-dopant content. In the contribution we discuss the influence of the chemical modification on the functional response, i.e., dielectric properties versus frequency and temperature, polarisation – electric field dependence, leakage current and piezoelectric response of the as-prepared films.
9:45 AM - *ES4.17.03
ZnO Varistor Based Piezotronic Material
Till Froemling 1 , Peter Keil 1 , Nikola Novak 1 , Juergen Roedel 1
1 , Technical University of Darmstadt, Darmstadt Germany
Show AbstractIn recent years, the research field piezotronics gained a lot of attention. It has been shown to have huge potential for applications like nanogenerators, gated field effect transistors and sensors [1]. Zinc oxide nanowires that allow extensive deformation were the focus of many investigations of metal-semiconductor Schottky-barriers. However, ZnO is also well known for polycrystalline varistor materials. In this case, the potential barriers at grain boundaries inhibit electrical transport until breakdown at high voltages. Therefore, ZnO is often used for surge protection or for voltage regulation. The piezoelectric contribution to varistor properties has so far only been discussed with respect to the decrease of the onset of the non-linear current-voltage relationship and increase of leakage current due to possible potential barrier lowering. Hence, it is considered an unwanted effect in varistor applications.
In this work, the possibility of using varistor materials for piezotronic applications (e.g. as pressure sensor) will be discussed. Our investigations show a large impact of mechanical stress on the linear leakage current in polycrystalline ZnO varistor samples [2] and varistor bicrystals. Extensive conductivity changes could be induced in this low voltage region via application of uniaxial pressure. Hence, very high possible gauge factors (figure of merit for the use in strain/stress sensors) around 1000 can be obtained. Commercial sensors can reach only a factor of 200 so far. A physical model will be introduced to explain the observed behavior [3] and the results are compared with single crystal metal-ZnO Schottky barrier investigations. Evidence will be provided for varistor boundaries showing enhanced piezotronic properties compared to metal-ZnO Schottky barriers.
[1] Z.L. Wang, Nano Today, (2010), 5, 540-552
[2] R. Baraki, N. Novak, T. Frömling, T. Granzow, J. Rödel, Appl. Phys. Lett., (2014), 105, 111604
[3] R. Baraki, N. Novak, M. Hofstätter, P. Supancic, J. Rödel, T. Frömling, J. Appl. Phys., (2015), 118, 085703
10:15 AM - ES4.17.04
Temperature Dependence of the Piezotronic and Piezophototronic Effects in A-Axis GaN Nanobelts
Xingfu Wang 1 , Ruomeng Yu 1 , Zhong Lin Wang 1
1 , Georgia Institute of Technology, Atlanta, Georgia, United States
Show AbstractUpon mechanical straining, piezoelectric polarizations are created in materials lacking inversion symmetry or having polarization domains. By utilizing the strain-induced piezo-charges to tune/control the electronic transport and/or optoelectronic processes is known as the piezotronic and/or piezo-phototronic effect, respectively. In this work, the temperature dependence of both the piezotronic and piezo-phototronic effects is investigated in GaN nanobelts synthesized along the non-polar a-axis orientation. As cooling the system from 300 K to 77 K, the piezotronic effect in a-axis GaN is enhanced by over 440% owing to the increased effective piezoelectric polarizations resulted from the reduced screening effect. Two independent processes are discovered to form a competing mechanism through the investigation of the temperature dependence of the piezo-phototronic effect in a-axis GaN. Theoretical simulations are conducted to systematically analyze the energy band diagrams and explain the working mechanism. This study presents in-depth understandings about the temperature dependence of the piezotronic and piezo-phototronic effects in a-axis GaN and provides guidance for their potential applications in electromechanical/optoelectronic devices.
10:30 AM - *ES4.17.05
Nonvolatile Memory and Optoelectronic Properties of Ferroelectric/Semiconductor Heterostructures
Tom Wu 1
1 , King Abdullah University of Science and Technology (KAUST), Thuwal Saudi Arabia
Show AbstractFerroelectric thin films with symmetry-breaking spontaneous polarization naturally offer nonvolatile device operation, but their wide bandgap often limits their charge transport and photo response. On the other hand, ferroelectric/semiconductor heterostructures feature a switchable depletion layer; thereby their current-perpendicular-to-plane transport can be effectively modulated by both electrical voltage and light illumination. To illustrate this device concept, we will first discuss a nonvolatile memory made of ferroelectric Sm0.1Bi0.9FeO3 and semiconductor Nb-doped SrTiO3, where a tunnelling electroresistance as large as 105 is achieved, which is accompanied by a tunable photovoltaic effect. Next, we will discuss a colossal persistent photoconductivity observed at room temperature in such thin-film junctions, where the junction conduction is enhanced by six orders in magnitude under X-ray illumination. Overall, such epitaxial ferroelectric/semiconductor junctions offer a viable platform to explore non-volatile memory and optoelectronic functionalities in artificial heterostructures.
ES4.18: Smart Flexible Electronics
Session Chairs
Friday PM, April 21, 2017
PCC North, 200 Level, Room 229 A
11:30 AM - *ES4.18.01
Using Silicon-Based Anisotropic Piezoelectricity for Robust Design of Ultrathin Bendable ICs and Sensors
Luigi Occhipinti 1
1 , University of Cambridge, Cambridge United Kingdom
Show AbstractThin-film, organic, printed and large-area electronics is a new way of making electronics enabling bendable and conformable systems-in-foil. These capabilities cover a wide range of applications, from wearable electronics for medical, sport and wellness, to ultra-thin, lightweight, and rollable displays, light sources or large-area sensors, up to miniaturized and energy autonomous smart sensors, with analogue sensor front-end, data processing and communication abilities, as needed in future IoT devices.
A silicon die thinned down to 50 microns or less becomes bendable to the same level of the plastic foil substrate, providing the system with key benefits of high speed logic, accurate analogue electronics, high density data storage, RF and mechanical energy harvesting [1].
This is advantageous e.g. in electrochemical sensors and bioelectronic devices that go into implantable and conformable devices, including soft substrates, elastomers, etc. [2]
However, as opposite to non ceramic-based materials commonly adopted in printed and flexible electronics, crystalline silicon shows multiple piezoeffects, both on passive and active devices [3].
Starting from the observation that silicon piezoeffects depend on its crystalline orientation, this talk will explore ways of using the anisotropic piezoelectric behavior of integrated silicon-based passive and active devices to make sensors of mechanical stress and compensation networks for robust design of bendable silicon ICs.
Bonding a small IC, after post-processing of the IC pads in order to obtain metallic bumps or pillars, and after singulation, by conventional flip-chip approaches so that the full system can be thin and bendable, with the exception of a relatively small area where the (rigid) silicon die is mounted and connected.
The talk will also review assembly techniques of thinned and ultrathinned dice on flexible substrates, and propose a way to control the stress and strain and to adapt modelling and simulation parameters in such a way that both yield and reliability of hybrid flexible electronic systems are optimised by using thinned silicon ICs custom designed for bendability.
This latter aspect is relevant in mechanical sensors that use bendability as part of their transduction mechanism. It is the case of relatively small strain gauge sensors connected to a silicon IC and possibly antenna to perform as a wireless autonomous sensor module.
References
[1] L. Occhipinti et al. “Flexible and conformable strain gauges for smart pressure sensors systems: static and dynamic characterization”, Proceedings of the 15th IEEE International Conference on Nanotechnology July 27-30, 2015, Rome, Italy
[2] R.F. de Oliveira et al. “Water-gated organic transistors on polyethylene naphthalate films”, Flex. Print. Electron 1 (2016) 025005
[3] Fabiano Fruett, “The piezojunction effect in silicon, its Consequences and Applications for Integrated Circuits and Sensors” master in electrical engineering, dissertation thesis, 2001
12:00 PM - ES4.18.02
Hybridized Nanogenerator for Simultanously Scavening Solar, Thermal and Mechanical Energies
Ya Yang 1
1 , Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, None Selected, China
Show AbstractHybridized nanogenerator for simultanously scavening solar, thermal, and mechanical energies
Ya Yang*
*E-mail:
[email protected]Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, China
Abstract: Scavenging biomechanical energy from human motions as a mobile power source has potential applications for driving some personal electronics, especially in the remote areas. A critical issue is how to obtain high efficient electric energy from one human motion. We report a hybridized electromagnetic-triboelectric nanogenerator for high efficient scavenging of biomechanical energy from human motions. The hybridized nanogenerator exhibits the much better conversion efficiency and charging performance than that of the individual energy-harvesting unit (triboelectric nanogenerator or electromagnetic generator). The produced energy by using the hybridized nanogenerator to scavenge the biomechanical energy can be utilized to sustainably power some electronic devices such as a commercial globe light, a temperature sensor and a wireless pedometer to realize self-powered systems. These works push forward a significant step toward energy harvesting from human motions and the potential applications in sustainably powering wearable electronics.
Refs:
(1) Shuhua Wang, Zhong Lin Wang*, and Ya Yang*. "A one-structure-based hybridized nanogenerator for scavenging mechanical and thermal Energies by triboelectric-piezoelectric-pyroelectric effects", Advanced Materials, 2016, 28, 2881-2887.
(2) Shuhua Wang, Xiaojing Mu, Ya Yang*, Chengliang Sun, Alex Yuandong Gu, and Zhong Lin Wang*."Flow-driven triboelectric generator for directly powering a wireless sensor node", Advanced Materials, 2015, 27, 240-248.
(3) Kewei Zhang, Zhong Lin Wang*, and Ya Yang*. "Conductive fabric based stretchable hybridized nanogenerator for scavenging biomechanical energy", ACS Nano, 2016, in press.
(4) Shuhua Wang, Xue Wang, Zhong Lin Wang*, and Ya Yang*."Efficient scavenging of solar and wind energies in smart city", ACS Nano, 2016, in press.
(5) Xue Wang, Shuhua Wang, Ya Yang*, and Zhong Lin Wang*. "Hybridized electromagnetic-triboelectric nanogenerator for scavenging air-flow energy to sustainably power temperature sensors", ACS Nano, 2015, 9, 4553-4562.
12:15 PM - *ES4.18.03
Triboelectric Composite Generators and Impact Sensors via Soft Material 3D Moulding
Lucia Beccai 1 , Majid Taghavi 1 , Massimo Totaro 1
1 , Istituto Italiano di Tecnologia, Pontedera Italy
Show AbstractTriboelectricity has been recently intensively investigated as a simple and cost-effective approach for mechanical energy harvesters and self-powered sensors [1-4]. At the same time, today in the robotics field the use of soft and deformable technologies represents a new approach to build soft robots and wearable systems that will have an effective interaction with real-world environment and humans [5]. We have introduced a totally new generation of triboelectric composites, which can be built with simple processes in any 3D shape, and can be adopted as multi-directional pressure sensors or energy harvesters [6]. In a first stage, a sponge rubber containing conductive disordered wire was addressed. The output power was around 60nW when applying a force with frequency of 2Hz and a produced strain of 45%. In a second stage, the generated power was enhanced of nearly hundreds of times, when creating a suitable air gap only between the embedded metal wire and the rubber matrix. Hence, bulk rubber was used instead of the previous sponge PDMS material, and this aspect contributed to an increase of the surface contact area between rubber and metal. Moreover, the applied mechanical energy is transferred to the wire/rubber interface, rather than being wasted in the sponge. Also, robustness is enhanced with respect to the preliminary solution [6]. Therefore, we built a composite integrating rubber, a conductive wire having small air gaps trapped around, and a reference electrode still placed in the composite and fully in contact with the rubber matrix. Such basic features bring unique properties, i.e. external mechanical stimulations have no need of a preferred surface or direction of application. The reference wire can also be external to the composite or connected to ground. Like in the previous case, the generated power was relative to the strain, stress and frequency. Specifically, we studied how contact-release speed affects triboelectric energy harvesting [7]. We will give an overview of the cited works, and then report on our current investigations about the development soft triboelectric effect-based pads that can be used to measure impact force. The presented approach can be used in a broad range of inexpensive energy harvesting and/or sensing applications, mainly addressing the wearable and soft robotics fields.
[1] B. Zhua, et al., Nano Energy, 14 (2015), 126.
[2] C. Laschi and M. Cianchetti, Frontiers in Bioengeneering and Biotechnology 2 (2014) 3.
[3] Z. L. Wang, et al., Energy & Environmental Science, 8 (2015) 2250.
[4] M. Taghavi, et al., Applied Surface Science, 323, (2014) 82
[5] M. Taghavi, et al., Nano Energy, 13, (2015) 92.
[6] M. Taghavi, et al., Advanced Energy Materials, 4 (2014).
[7] M. Taghavi, et al., Nano Energy 8 (2015).
12:45 PM - ES4.18.04
Liquid Metal Droplet Based Tube-Shaped Electrostatic Energy Harvester
Haotian Chen 1 , Zongming Su 1 , Mengdi Han 1 , Dongmin Chen 1 , Haixia Zhang 1 , Song Yu 1
1 , PKU, Beijing China
Show AbstractWith the rapid increasing of portable electronics, scavenging ambient mechanical energy as sustainable energy is a promising way to power microelectronic devices. Triboelectric generators reported in recent years mainly use solid materials, so that the contact between triboelectric pairs can’t reach 100% considering the roughness of the surface. Therefore, a liquid metal droplet (LMD)-based electrostatic-based generator is reported for high power generation. Due to liquid metal’s unique property, the generator allow a total contact and guarantee large amount of charges transferring.
The generator consists of a LMD encapsulated in a polyethylene tube and double-helix copper electrodes around the tube outside. At first, there is no charge accumulated on the PE surface. Once the LMD is injected into the tube, according to their different ability in attracting electrons, the interface of LMD will carry positive charges and corresponding PE surface will carry negative charges. Then the LMD move inside the tube, all the inner PE surface will gain negative charges and the same amount of positive charge will distribute on the LMD surface. Initially, the LMD is located on the left electrode and negative charges accumulated on it due to electrostatic induction. When the LMD flows from left electrode to the right electrode, the moving droplet affect the charges distribution driving electrons moving from left electrode to right electrode and generate a transient current. With double-helix-structured electrodes, when flowing along the tube, LMD drives electrons transferring between two electrodes several times, which up-convert output frequency and enhance efficiency dramatically.
The device has two working conditions. The first one is that LMD moves in horizontal direction. In this condition, the output potential difference is large and the frequency is multiplied according to design of electrode. The second working condition is that LMD moves up-and-down, which is seldom because it is very easy for LMD to slip on PE surface. This condition generates smaller potential difference. Both of the working conditions benefit energy harvesting.
In the test, 30.6V peak-to-peak voltage and 298nA peak-to-peak current can be obtained. Alternative electrodes ensures to multiply frequency to increase the efficiency. The volume of liquid metal also influence the output. Larger volume decreases the output voltage because enlarged volume resulting in enlarged contact surface, which reduces the voltage potential difference between neighboring electrodes. The generator can charge a 1μF capacitance to 1.81V in 150s at 2Hz. Average power of 727nW can be obtained at 100MΩ load.
As copper electrode is double-helix-structured, the device can be bend with little influence on conductivity. In this way, the device can be wind up and connect two ends to form a hollow loop. With wearing this wristband-shaped generator, people can harvest his mechanical energy when he move his wrist.
ES4.19: Piezoelectric and Triboelectric Nanogenerators
Session Chairs
Friday PM, April 21, 2017
PCC North, 200 Level, Room 229 A
2:30 PM - ES4.19.01
High Performance Broadband UV/Visible Photodetector of ZnO/ZnSe Core/Shell Nanowire Array and Its Self-Powered Performance Based on Piezophototronic Effect
Shuke Yan 1 , Satish Rai 1 , Zhi Zheng 1 , Weilie Zhou 1
1 , University of New Orleans, New Orleans, Louisiana, United States
Show AbstractIn recent years, the piezo-phototronic effect, coupling of piezoelectric and optical properties in semiconductor materials, has attracted much attention due to its capabilities of boosting device performance significantly. In this paper, we report a broadband UV/visible photodetector based on ZnO/ZnSe type-II heterojunction core/shell nanowire array and its self-powered photodetection. The integrated photodetector based on the ZnO/ZnSe core/shell structure is capable of detecting the whole range of the visible spectrum as well as UV light, and it is further enhanced by three orders of magnitude in relative responsivity, by applying compressive load under different wavelength excitation sources. The significant increase is believed to arise from piezo-phototronic effect, in conjugation with abrupt interface between ZnSe and ZnO which promotes type-II charge carrier separation and also inhibits recombination loss. Moreover, the device exhibits self-powered photodetection behavior under UV/visible light illumination. This work is expected to generate broad interest in exploring the application using type II heterostructure for broadband UV/visible photodetection under both powered and self-powered conditions.
2:45 PM - ES4.19.01.5
Auxetic Foam Based Triboelectric Nanogenerator with Self Powered Strain Sensing Capabilities to Monitor Human Body Movement
Steven Zhang 1 , Ying-Chih Lai 2 , Xu He 1 , Ruiyuan Liu 1 , Yunlong Zi 1 , Zhong Lin Wang 1 3
1 , Georgia Institute of Technology, Atlanta, Georgia, United States, 2 , National Chung Hsing University, Taichung Taiwan, 3 , Beijing Institute of Nanoenergy and Nanosystems, Beijing China
Show AbstractFlexible, stretchable, highly sensitive, and low cost strain sensors are crucial devices in functional wearable devices, health monitoring systems, and human-machine interfaces. Recently, many types of different strain sensors devices were invented. However, most of them require a foreign rigid and boxy power supply, which hinders their practical applications in flexible electronics. In this study, we fabricated a self-powered flexible strain sensor triboelectric nanogenerator (TENG) by using an auxetic polyurethane foam, conductive fabric, and polytetrafluroethylene (PTFE) film. The auxetic polyurethane foam exhibits a negative Poisson’s ratio, which caused the foam to expand in all directions when a strain force was applied. The expanded auxetic polyurethane foam contacted the shell of PTFE film, which will produce the triboelectric charges. Due to a larger contact area between the PTFE film and the polyurethane foam as the foam was stretched, this device can function effectively as a strain sensor. The sensitivity of this method is explored, and this sensor has the highest sensitivity in all TENG devices that were used as a strain sensor. Different applications of this strain sensor were also demonstrated, including a human body monitoring system, a self-powered scale to measure different weights, and a seat belt to sense body movements inside a car seat.
3:00 PM - ES4.19.02
Self-Powered Electrochemical Sensors for Glucose and Lactate Detection
Zong-Hong Lin 1 , Ting-Wei Chang 1 , Chuan-Hua Chen 1
1 , National Tsing Hua University, Hsinchu Taiwan
Show AbstractElectrochemical sensors which utilize the direct redox reactions of biological samples have been demonstrated as efficient analytical approaches over the past decades. In recent years, several new sensing concepts and related devices have been proposed. For examples, wearable and flexible textile-based electrochemical sensors have shown their potential to detect lactate in sweat. In this study, we developed the self-powered electrochemical sensors for glucose and lactate detection by integrating triboelectric nanogenerator (TENG) with electrochemical cells. TENG was firstly developed in 2012 and now has become a good candidate as the power source for self-powered sensing systems due to its performance in converting mechanical energy into electricity. In our design, gelatin/glycerol and PTFE films were selected as the triboelectric layers of TENG due to their biocompatible properties. The output voltage and current generated from the TENG were 500 V and 45 µA, respectively. In the electrochemical sensing units, carbon fiber fabrics were adopted as the conductive substrates to assemble electrocatalytic nanomaterials. The results showed that the presence of bimetallic Au/Pd nanoparticles is crucial in self-powered electrochemical sensors as the overall sensitivity is significantly improved. The linear range for the detection of glucose and lactate were 0.2~2 mM and 0.1~10 mM, respectively. Now we are moving forward to fabricate all self-powered textile-based electrochemical sensors and believe they will help people to monitor their health status immediately.
References:
Lin, Z.-H.; Zhu, G.; Zhou, Y. S.; Yang, Y.; Bai, P.; Chen, J.; Wang, Z. L. Angew. Chem. Int. Ed. 2013, 52, 5065–5069.
Lin, Z.-H.; Xie, Y.; Yang, Y.; Wang, S.; Zhu, G.; Wang, Z. L. ACS Nano 2013, 7, 4554–4560.
Lin, Z.-H.; Cheng, G.; Yang, Y.; Zhou, Y. S.; Lee, S.; Wang, Z. L. Adv. Funct. Mater. 2014, 24, 2810–2816.
Chang, T.-H.; Peng, Y.-W.; Chen, C.-H.; Chang, T.-W.; Wu, J.-Y.; Hwang, J.-C.; Gan, J.-Y.; Lin, Z.-H. Nano Energy 2016, 21, 238–246.
Chang, T.-W.; Wang, C.-W.; Chen, C.-H.; Li, Y.-C.; Hsu, C.-L.; Chang, H.-T.; Lin, Z.-H. Nano Energy 2016, 22, 564–571.
3:15 PM - ES4.19.03.5
Electric Eel-Skin-Inspired Mechanically-Durable and Super-Stretchable Nanogenerator for Deformable Power Source
Ying-Chih Lai 1 2 , Jianan Deng 2 , Simiao Niu 2 , Wenbo Peng 2 , Changsheng Wu 2 , Ruiyuan Liu 2 , Zhen Wen 2 , Zhong Lin Wang 2 3
1 , National Chung Hsing University, Taipei Taiwan, 2 , Georgia Institute of Technology, Atlanta, Georgia, United States, 3 , Beijing Institute of Nanoenergy and Nanosystems, Beijing China
Show AbstractSoftness, body/shape compliance and the capability of producing electricity are salient and special features of electric eel skins. To pursue those attributes, we present the first intrinsically mechanically durable and resilient nanogenerator by using triboelectric effects; skin-like triboelectric nanogenerator (SLTENG). The SLTENG realized through composed of intrinsic stretchable components can generate electricity from touch regardless of various "extreme" deformation required from uses, such as extreme omnidirectional stretch of over 300 % strain, and multiple twists and folds. With the perfect flexibility, the nanogenerator can be fully conformal on various non-planar or irregular objects, including human bodies, spheres, and tubes, etc., to act as power sources for other components. Particularly, even experiencing severe tearing damages, the device can well retain its stretchability and function of generating electricity. These newly-designed features can greatly broaden the nanogenerators to produce electric energy whenever desired. Also, based on the exceptional tolerability, the nanogenerator can be highly conformable on various non-planar surfaces, promising immense applications in harvesting energy on arbitrary desired objects. The studies of the performance dependence on the thickness of dielectric layer, temperature, and applied forces have been included. And, the mechanisms about the influence on the performance at various kind of deformation have been suggested. The produced energy has been demonstrated to be able to sustainably drive a commercial smart watch. Based on the electric eel skin-like device, we further demonstrated the first fully self-sufficient and highly adaptive e-skin system that can map touch by responding with visual light-emitting diode (LED) signals without the need of external power supply. The presented results are timely and beneficial for the development of a wide range of deformable/wearable/biomedical electronics and self-powered human-interactive systems
3:30 PM - ES4.19.04
Electrospun Poly(L-Lactic Acid) Nanofibers for Nanogenerator and Diagnostic Sensor Applications
Kailiang Ren 1 , Gengrui Zhao 1 , Baisheng Huang 1 , Jianxiong Zhu 1 , Jinxi Zhang 1 , Aochen Wang 2 , Zhong Lin Wang 1
1 , Beijing Institute of Nanoenergy and Nanosystems, Beijing China, 2 School of Electronic Information, Tianjin University, Tianjin, Tianjin, China
Show AbstractIn this investigation, we show for the first time that the electrospinning can be used as a one-step method to produce piezoelectricity in PLLA (poly(L-lactic acid) nanofibers along the direction of the fiber axis. The characterized data shows that the super-critical CO2 treatment can greatly enhance the piezoelectricity of electrospun PLLA fibers. Further, the measurement results by a simple push-release testing process show that a single electrospun PLLA fiber can generate a current of 8 pA and a voltage of 20 mV, which is similar with the one generated from electrospun PVDF nanofibers. Finally, a single PLLA fiber-based blood pulse sensor shows around a 2 pA output for a blood pulse measurement. Due to easy fabrication and relatively simple structure, this device enables a broad range of promising future applications in the medical sensor area.
ES4.20: Piezoelectric and Triboelectric Materials and Devices
Session Chairs
Qingliang Liao
Yunlong Zi
Friday PM, April 21, 2017
PCC North, 200 Level, Room 229 A
4:15 PM - ES4.20
ES4.20.01 transferred ES4.10.03 Nan Pan
Show Abstract4:15 PM - ES4.20
ES4.20.02 transferred ES4.18.03 Beccai Lucia
Show Abstract4:15 PM - ES4.20
ES4.20.03 tranferred ES4.19.05 Yi Xi
Show Abstract4:15 PM - ES4.20
ES4.20.04 transferred ES4.8.04 Guanlin Liu
Show Abstract