Symposium Organizers
Ji Su NASA Langley Research Center
Li-Peng (Leo) Wang TricornTech Corporation
Yasubumi Furuya Hirosaki University
Susan Trolier-McKinstry The Pennsylvania State University
Jinsong Leng Harbin Institute of Technology
V1: Magnetostrictives
Session Chairs
Monday PM, December 01, 2008
Commonwealth (Sheraton)
9:30 AM - **V1.1
Magnetomechanical Behavior of Iron-Gallium Alloys.
Jayasimha Atulasimha 1 , Alison Flatau 2
1 Mechanical Engineering, Virginia Commonwealth Univ., Richmond, Virginia, United States, 2 Aerospace Engineering, University of Maryland, , College Park, Maryland, United States
Show Abstract10:00 AM - V1.2
Magnetostrictive Fe-Ga Wires with <100> Fiber Texture.
Shannon Farrell 1 , Patti Quigley 1 , Kyle Avery 1 , David Bligh 1 , Allison Nolting 1 , Timothy Hatchard 2 3 , Stephanie Flynn 2 , Richard Dunlap 2 3
1 Dockyard Laboratory (Atlantic), Defence R&D Canada, Dartmouth, Nova Scotia, Canada, 2 Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada, 3 Institute for Research in Materials, Dalhousie University, Halifax, Nova Scotia, Canada
Show AbstractFe-based alloys that combine toughness, formability, and mechanical strength with large magnetostriction are becoming increasingly more popular for use as magnetostrictives. In particular, Fe-Ga alloys, that exhibit approximately 20 % of the strain of traditional rare earth element-based giant magnetostrictive alloys (ex., Terfenol-D), are more robust, less expensive and more versatile (may be employed in tension). Fe-Ga magnetostrictives hold promise for energy harvesting applications that supplement battery power to alleviate strain put on current power storage media.Recently, low-cost processing approaches that produce textured thin bodies have engendered interest as a cost-effective approach for fabrication of Fe-Ga alloys. In particular, wire-forming methods that strictly control the solidification direction could lead to some measure of crystallographic texture control that is required for the development of large magnetostriction. The Taylor wire method for processing Fe-Ga alloys is similar to other non-equilibrium techniques (melt spinning, mechanical alloying, etc.) and is both interesting and promising for preparation of magnetostrictive wire. In this paper, the Taylor wire method will be discussed relative to other non-equilibrium techniques for production of textured Fe-Ga magnetostrictive alloys. The influence of parent material (form and composition), experimental drawing techniques and annealing/quench approaches to wire development will be discussed in terms of the resultant microstructure, crystallographic texture and magnetostriction. Results show that the Taylor wire method is an effective and versatile means to draw 1-3 mm diameter textured Fe-Ga wire. Modification of the parent material, temperature and drawing speed led to a variety of wire morphologies while quench conditions had a profound effect on texture development. In the absence of quenching, the 2-3 mm diameter wires showed no indication of a preferred fiber texture. Experimentation with quench conditions on texture development resulted with the production of a strong <100> fiber texture. Preliminary magnetostriction measurements, in the absence of prestress, indicated a maximum magnetostriction of ~160 ppm in a saturation field less than 0.2 Tesla. Magnetostriction values were similar to that expected for oriented Fe-Ga bulk materials with similar composition (up to 170 ppm strain along <100>) and are considered a significant strain for bulk polycrystalline alloys without a pre-stress or a stress-annealing treatment.
10:15 AM - V1.3
Rapid-solidified Magnetostrictive Polycrystalline Strong-Textured Galfenol (Fe-Ga) Alloy and its Applications for Micro Gas-valve.
Chihiro Saito 1 , Teiko Okazaki 2 , Yasubumi Furuya 3
1 NJC Research Center , Namiki Precision Jewel Co.,Lt, Tokyo Japan, 2 Physical Science , Hirosaki University , Hirosaki Japan, 3 Intelligent Machines and System Engineering, Hirosaki University, Hirosaki Japan
Show AbstractPolycrystalline strong-textured Galfenol (Fe-Ga) alloy ribbon was fabricated by rapid-solidification melt-spinning method. Based on the characterization and discussion of the enhanced magnetostrion mechanism in the ribbon samples, the proto–type micro gas-valve was developed by using bimorph type Galfenol actuator. In recent, A.Clark found that the FeGa (Ga=17-19at%) single crystal showed considerably large magnetostriction of 400 ppm in low magnetic field. however, their fabrication process is not so easy and very expensive. As we know, the advantage of melt-spinning method is extension of solid solubility, grain refinement, reduction or elimination of micro-segregation, and formation of non-equilibrium metastable phase during one process. If the disordered A2 phase at high-temperature region can be frozen to room temperature without precipitating the ordered phases such as fcc ordered L12 as well as bcc ordered D03 phases, more large magnetostriction can be expected even in polycrystalline structure.The former part of this paper, the experimental results of the changes of magnetostriction in the rapid-solidified Fe-Ga system ribbons after heat treatment etc. are overviewed including their special unique microstructures. In fact, the melt-spun, rapid solidified Galfenol (Fe-Ga, (Ga=17-19at%) ribbon sample showed clear angular dependency on magnetostriction and large magnetostriction (=180-200ppm). This large magnetostriction is caused by non-precipitating of the ordered phases, the release of considerable large internal stresses in as-spun ribbon as well as the remained [100] oriented strong textures. These bring the materials improvement in strength toughness, hardness, wear resistance, heat resistance, and corrosion resistance and these seem worthy for engineering application for a actuator/sensor devices. Therefore, in the latter part of this paper, we will introduce the magnetically controllable micro gas-valve which is composed by the bimorph-type FeGa/Ni or FePd /Ni thin plates with the opposite value (FeGa(+), FePd(+), Ni(-)) of magnetostriction coefficient. Large displacement of opposite type could be obtained and their hysteresis curve changed depending on the volume fraction of the composite structure, The dynamic properties of the developed prototype magnetic micro-gas valve will be shown in more detail.
10:30 AM - V1.4
Development of Actuators and Motors Based on Giant Magnetostrictive Materials by a Modular Innovative Approach.
Nanjia Zhou 1
1 , Pittsburg State University, Pittsburg, Kansas, United States
Show Abstract10:45 AM - V1.5
Development of Fe-Ga-Al(Galfenol) System Alloys with Large Magnetostriction and High Strength by Precipitation Hardening of the Dispersed Carbides.
Toshiya Takahashi 1 , Teiko Okazaki 1 , Yasubumi Furuya 1
1 Science and Technology, Hirosaki university, Hirosaki Japan
Show Abstract While magnetostriction materials is observed in all ferromagnetic materials, new materials that exhibit large Joule magnetostriction, at low magnetic fields, are of interest for actual engineering use as acoustic sensors and generators, motors, actuator, damping devices, torque sensors, poisoning devices, transducer etc.. The earliest crystalline magnetostriction alloys used in transducer were Nickel based alloy (Ni-Co system alloys etc λmax=30ppm), and then, large magnetostriction values was obtained in RFe2 intermetallic compounds C15 structure(R=rare-earth elements) such as Terfenol-D alloy with a composition (Dy0.7Tb0.3) Fe2. These alloys show magnetostriction as large as 1000ppm. However, Dy and Tb are high costs, and C15 structure is brittleness, and high fields required for magnetic saturation. In recent work, Fe-Ga and Fe-Ga-Al alloy (Galfenol) produced by Clark et al. Fe-Ga system alloy have A2 structure with (1) high mechanical strength compared to Terfenol, (2) good ductility, (3) large magnetostriction value, (4) low saturation fields, (5) low material prices. However, a strength property is required for industrial application since various applications for actuator/sensor devices are required recently under severe environment, and component mass saving in the machinery etc. This study’s purpose is development of Fe-Ga-Al (Galfenol) system alloy with large magnetostriction and high strength by precipitation hardening effect of the dispersed carbides for application under severe environment and down-sizing. Three kinds of composition bulk samples with additional elements of Carbon, Zirconium, Niobium and Molybdenum to Fe-Ga-Al alloy, (Fe-Ga0.15-Al0.05) 99.0-X0.5-C0.5 (X=Zr, Nb, Mo) [at.%], were prepared. Those bulk samples were given heat treatment after the arc melting. Then, metallurgical characterizations, the magnetic characteristic, magnetostriction characteristic under a free-compressive stress condition and strength property were studied. As a result, (Fe-Ga0.15-Al0.05)99.0-Zr0.5-C0.5 [at.%] arc melted and annealed sample showed a maximum magnetostriction of λmax=90ppm and tensile stress σB=800MPa level, (Fe-Ga0.15-Al0.05)99.0-Nb0.5-C0.5 sample showed λmax=60ppm, σB=730MPa level, and (Fe-Ga0.15-Al0.05)99.0-Mo0.5-C0.5 sample showed λmax=90ppm and tensile stress σB=780MPa level. The compressive stress effect to magnetostriction in some alloy will also investigated. As magnetostrictive alloy with high tensile strength like an 800MPa was not yet reported up to the present, those materials developed here will have a potential of industrial applications such as actuator and sensor, for example, transducer, and force sensor under severe environment.
V2: Multfunctionals and Multiferroics
Session Chairs
Hiroshi Asanuma
Yasubumi Furuya
Monday PM, December 01, 2008
Commonwealth (Sheraton)
11:30 AM - V2.1
Investigation of Surface und Bulk Properties of Ni2MnGa via X-ray Absorption Spectroscopy (XAS) and X-ray Magnetic Circular Dichroism (XMCD).
M. Kallmayer 1 , P. Poersch 1 , T. Eichhorn 1 , G. Jakob 1 , H. Elmers 1 , C. Jenkins 2 , C. Felser 2 , R. Ramesh 3 , M. Huth 4
1 Institut für Physik, Johannes Gutenberg-Universität Mainz, D-55128 Mainz Germany, 2 Institut für Anorganische und Analytische Chemie, Johannes Gutenberg-Universität Mainz, D-55128 Mainz Germany, 3 Department of Materials Science & Engineering, University of California, 94720 Berkeley, California, United States, 4 Physikalisches Institut, Goethe-Universität Frankfurt/Main, D-60438 Frankfurt/Main Germany
Show Abstract11:45 AM - V2.2
Growth and Structure of Epitaxial Ni-Mn-Ga Magnetic Shape Memory Films.
Gerhard Jakob 1 , Tobias Eichhorn 1 , Catherine Jenkins 1 2 3 , Peter Poersch 1 , Hans-Joachim Elmers 1 , Claudia Felser 2 , Ramamoorthy Ramesh 3 , Michael Huth 4
1 Institute of Physics, University of Mainz, Mainz Germany, 2 Institute for Anorganic and Analytical Chemistry, University of Mainz, Mainz Germany, 3 Department of Materials Science & Engineering, University of California, Berkeley, California, United States, 4 Physics Institute, University of Frankfurt, Frankfurt Germany
Show AbstractNew perspectives for magnetically induced actuation have been opened by the discovery of huge magnetic field induced strain in Ni2MnGa and related compounds. An alignment of the crystallographic axes with respect to the magnetic field direction is required in order to achieve maximum strain. As thin films are clamped to the substrate, epitaxial free standing films are finally required. We prepared Ni2MnGa films by sputtering from compound targets onto heated single crystalline substrates. As target materials we used the stoichiometric compound Ni2MnGa, delivering films with the martensite transition below room temperature, and a manganese rich target (Ni1.96Mn1.22Ga0.82). Sputtering from the latter resulted in martensite temperatures above 100°C. Epitaxial growth was achieved on a variety of substrates among them MgO(100), Al2O3(11-20), and BaF2(111) yielding films with different out of plane orientations switching from (100) to (110) to (111), respectively. In all cases four circle diffractometry proved the epitaxial in plane orientation. Temperature dependent x-ray diffraction was used to correlate the structural transition with anomalies in the temperature dependent magnetization and electrical transport. High substrate temperatures were beneficial in order to achieve high saturation magnetization. Four circle diffraction showed the films being in the martensite state at room temperature to possess a 7-fold superstructure. This is evident by superlattice lines in x-ray diffraction. The splitting in different variants can also be reconstructed from the intensity distribution in reciprocal space.With respect to free standing films we prepared highly textured films on water soluble single crystalline NaCl substrates. The in-plane orientation shows two epitaxial variants to coexist. Another way to free standing cantilevers was using a focussed ion beam system to cut free standing cantilevers. With optical microscopy and atomic force microscopy we observed the martensite twinning structure and its evolution during the transition. A partial magnetic field induced movement of the twin boundaries in the free standing cantilevers was observed using atomic force microscopy. Annealing experiments to release the blocking stress are in progress.
12:00 PM - V2.3
Magnetostriction in Fe-Co Binary Probed Using the Thin Film Composition Spread Technique.
Dwight Hunter 1 , R. Takahashi 1 , R. Suchoski 1 , J. Hattrick-Simpers 1 , S. Lofland 2 , M. Wuttig 1 , I. Takeuchi 1
1 Department of Materials Science and Engineering, University of Maryland, College Park, Maryland, United States, 2 Department of Physics and Astronomy, Rowan University, Glassboro, New Jersey, United States
Show AbstractPrevious investigation of the Fe-Ga binary system using the combinatorial approach showed that this technique can be used successfully to capture bulk trends of magnetostriction as a continuously changing function of composition [1]. Here, the combinatorial technique was applied in the study of magnetostriction in Fe-Co thin film samples. The films with continuously varying composition were deposited at room temperature using a magnetron co-deposition system onto a micro-fabricated array of cantilevers on a Si wafer. Using an optical high-throughput measurement system, the change in magnetostriction across the Fe-Co phase diagram was obtained by systematically monitoring the deflection of each cantilever. The values of magnetostriction as a function of composition mirrors the bulk trend [2] in which the striction rises to two maxima, one at Fe50Co50 composition and the other spanning over the range between 19 and 27 atomic % of Fe. Microstructural analysis of synchrotron microdiffraction data indicates that the nanocrystal grains are randomly oriented polycrystalline films. In conjunction with annealing experiments, [3] the results suggest that the maximum striction observed in the Co-rich region might be due to a structural transition occurring close to the bcc/(hcp+fcc) phase boundary. It may be suspected that the peak of the magnetostriction in the Co-rich region is of similar origin as the one reported in Fe-Ga [4] where the maximum striction occurs at the bcc/DO3 and DO22/DO19/ L12/bcc boundaries. Results of mapping of magnetostriction for other systems will also be discussed. [1] Hattrick-Simpers, et al., “Combinatorial Investigation of Magnetostriction in Fe-Ga and Fe-Ga-Al”, to be published.[2] Y. Masiyama, Sci. Rpts. of Tohoku Imperial U., 21, 394 (1932).[3] M. Wuttig and L. Dai, Scripta Mat., to be published.[4] G. Petculescua, et al., J. Appl. Phys. 97, 10M315 (2005).This project was funded by ONR-MURI N000140610530.
12:15 PM - V2.4
Magnetoelastic Material as a Biosensor for the Detection of Salmonella Typhimurium.
Ramji Lakshmanan 1 , Rajesh Guntupalli 4 1 , Shichu Huang 1 , Michael Johnson 1 , Leslie Mathison 1 , I-Hsuan Chen 3 , Valery Petrenko 2 , Zhong-Yang Cheng 1 , Bryan Chin 1
1 Materials Engineering, Auburn University, Auburn, Alabama, United States, 4 Department of Anatomy, Physiology and Pharmacology, College of VetirinaryMedicine, Auburn University, Auburn, Alabama, United States, 3 Department of Biological Sciences, Auburn Unviersity, Auburn, Alabama, United States, 2 Department of Pathobiology, College of VetirinaryMedicine, Auburn University, Auburn, Alabama, United States
Show AbstractMagnetoelastic materials are amorphous, ferromagnetic alloys that usually include a combination of iron, nickel, molybdenum and boron. Magnetoelastic biosensors are mass sensitive devices comprised of a magnetoelastic material that serves as the transducer and bacteriophage as the bio-recognition element. By applying a time varying magnetic field, the magnetoelastic sensor thin films can be made to oscillate, with the fundamental resonant frequency of oscillations depends on the physical dimensions and properties of the material. The change in the resonance frequency of these mass based sensors can be used to evaluate the amount of analyte attached on the sensor surface. Filamentous bacteriophage specific to S. typhimurium was used as a bio-recognition element in order to ensure specific and selective binding of bacteria onto the sensor surface. The sensitivity of magnetoelastic materials is known to be dependent on the physical dimensions of the material. An increase in sensitivity from 159Hz/decade for a 2mm sensor to 770Hz/decade for a 1mm sensor and 1100Hz/decade for a 500micron sensor was observed. The sensors were characterized by scanning electron microscopy (SEM) analysis assayed biosensors to provide visual verification of frequency responses and an insight into the characteristics of the distribution of phage on the sensor surface. The magnetoelastic sensors immobilized with filamentous phage are suitable for specific and selective detection of target analyte in different media. Certain modifications to the measurement circuit resulted in better signal to noise ratios for sensors with smaller dimensions (L<1mm). This was achieved by tuning the circuit resonance close to that of the sensor. According to models and preliminary tests, this method was anticipated in about a 5 times increase in signals for a 200×40×6microns. This technique and further studies into the design and modification of the measurement circuits could yield better, sensitive responses for sensors with smaller dimensions. The magnetoelastic materials offer further advantages of potential miniaturization, contact-less nature and ease of operation.
V3: Sensors and Novel Processing
Session Chairs
Shanyi Du
Frederic Dumas Bouchiat
Atulasimha Jayasimha
Jinsong Leng
Monday PM, December 01, 2008
Commonwealth (Sheraton)
2:30 PM - V3.1
Fabrication of Gas Nanosensors and Microsensors via Local Anodic Oxidation.
Braulio Archanjo 1 , Guilherme Silveira 1 , Alem-Mar Goncalves 1 , Diego Alves 1 , Andre Ferlauto 1 , Rodrigo Lacerda 1 , Bernardo Neves 1
1 Physics, UFMG, Belo Horizonte Brazil
Show AbstractA new nanosensor, and microsensor, fabrication method, employing scanning probe microscopy (SPM) and local anodic oxidation (LAO), is demonstrated. Two different metal oxides (MoOx and TiOx) are employed as proof-of-concept materials, producing sensors with suitable response and sensitivities down to low concentrations of both reducing and oxidizing gases. Using conventional optical lithography, a thin metal track (Mo or Ti), with electrical contacts, is patterned. The active region of the sensor is directly fabricated onto the track via SPM-assisted LAO, creating nano- and micro-scale metal oxide (MoOx or TiOx) structures, finalizing the sensor fabrication. Two distinct LAO routes, a slow (conventional) and a fast (unusual) one, are employed to produce nano- and micro-sensors, respectively, which are tested at different temperatures using CO2 and H2 as test gases. Sensitivities down to ppm levels are demonstrated and, in principle, this methodology, including both slow and fast LAO routes, could be applied to any desired metal or metal alloys, further extending sensing possibilities of designed nano- and micro-devices. Finally, this novel sensor design and fabrication concept is proposed on a way that it could be readily implemented in conventional industrial microfabrication processes.
2:45 PM - V3.2
Controlled Assemble and Microfabrication of Zeolite Nanoparticles on SiO2 Substrates for Potential Biosensor Applications.
Seckin Ozturk 1 4 , Kubra Kamisoglu 2 , Rasit Turan 1 3 , Burcu Akata 1 4
1 Micro and Nanotechnology, Middle East Technical University, Ankara Turkey, 4 Central Laboratory, Middle East Technical University, Ankara Turkey, 2 Chemical Engineering, Middle East Technical University, Ankara Turkey, 3 Physics, Middle East Technical University, Ankara Turkey
Show AbstractThe development of new fabrication methods of organized nanoparticles on surfaces is important for electronic, optoelectronic, biological, and sensing applications. Usually chemical modification of SiO2 substrates with silanization techniques are used for potential biosensor and electronic applications where the targeted biological components are assembled onto the modified substrates. By combining silanization methods with microfabrication technology, surfaces can be patterned with functional groups, making it possible to attach cellular structures such as microtubules or cells in specific locations.In such components, there is a great need to increase the sensitivity level of the fabricated device, and one way to achieve this can be done via further assembly of nanoparticles on the modified substrates which show promising characteristics for the immobilization of the targeted chemical/biological compounds. Zeolite nanoparticles were shown to display good interactions with biological molecules. They have remarkably large surface area that is available for the immobilization of different molecules, tunable surface properties for controlled variation of surface charge and hydrophilic/hydrophobic characteristics. The zeolite monolayers are suggested to be used as ideal media for organizing semiconductor quantum dots and nonlinear optical molecules in uniform orientations.In the current study, zeolite nanoparticles were organized into functional entities on silanized SiO2 substrates and microfabricated using the electron beam lithography (EBL). The effect of different silanization compounds and different techniques for zeolite assembly on the silanized surfaces were investigated. For that purpose, different experimental procedures and parameters were investigated to efficiently assemble zeolite crystals on SiO2 substrates. Spin-coating (SC) and ultrasound aided strong agitation (US) methods were tested using silanized zeolite micron- and nanoparticles. Both methods were facile in terms of experimental approach. Full coverage of the substrate was obtained after both methods, however strong agitation (US) leads to better organization of zeolite micro and nanocrystals. Furthermore, the obtained zeolite micropatterns formed on the Si wafer substrate were more fully covered upon using the silanized zeolite nanoparticles.
3:00 PM - V3.3
Growth of One-Dimensional Metal Oxide Nanostructures and Nanowire-based Devices.
Sanjay Mathur 1 2 , Sven Barth 2 , Francisco Hernandez-Ramirez 3 , Joan Daniel Prades 3 , Albert Romano-Rodriguez 3
1 Institute of Inorganic Chemistry, University of Cologne, Cologne Germany, 2 Department of CVD-Technology, Leibniz-Intitut für Neue Materialien, Saarbrücken Germany, 3 IN2UB and EME-Department of Electronics, University of Barcelona, Barcelona Spain
Show AbstractMonday 12/1New Presenter V3.3 @ 2:00 PMGrowth of One-Dimensional Metal Oxide Nanostructures and Nanowire-based Devices. Sven Barth
3:15 PM - V3.4
Catalyst-based Solid State Sensor Schemes for Wide Temperature Range Hydrogen Leak Detection.
Claudiu Muntele 1 , Sandra Sadate 1 , Malek Abunaemeh 1 , Cydale Smith 1 , Daniel McElhaney 1 , Jonathan Gardner 2 , Abdalla Elsamadicy 2 , Daryush Ila 1
1 , Alabama A&M University, Normal, Alabama, United States, 2 , University of Alabama in Huntsville, Huntsville, Alabama, United States
Show AbstractSilicon carbide based non-linear electronics devices (MOSFET, metal-semiconductor, or p-n junctions) are promising candidates for hydrogen detection schemes if used in conjunction with a good catalyst from the platinum group of elements. For the past decade, the emphasis was mostly on high temperature applications in the automotive (for hydrogen-fueled engines) and in the aerospace industry (for jet engines), but now the focus is broadening to include auxiliary systems such as storage tanks, fuel lines, fuel production systems, all operating in a wide range of temperatures, from ambiental (RT – room temperature) to cryogenic. Hydrazine is a particular hydrogen-containing chemical of interest, as is widely used as a fuel in rocket propulsion systems, fuel cells, pesticides, dyes etc. It is also a neurotoxin, causing damage to most organs in the human body. Therefore sensors able to detect hydrazine leaks at sub-ppm level at RT (anhydrous hydrazine melts at 2 °C and evaporates at 113.5 °C) and in a wide humidity range (hydrazine is fully miscible in water) are highly desirable. Sensitive analytical methods have been developed for the determination of hydrazine in air, water, food, drugs, and cigarette smoke. However, all these methods involve complicated analytical instrumentation generally available only in a specialized laboratory environment. From the variety of detection schemes available for portable devices, two seem of being the most commonly used: color-changing paper readers (e. g. MDA 7100 and newer) and fuel cell-based detectors (e. g. products of PureAire Monitoring Systems, Inc.).While high temperature operation is completely characterized for catalyst-based sensors, low temperature operation presents catalyst-related challenges (such as catalyst “poisoning” due to surface passivation), some of them little understood, some well characterized but without a functional solution. In this paper we are addressing, on a comparative basis, solutions to challenges associated with using catalysts as active agents in capacitive, non-linear (p-n structures), and linear (resistors) hydrazine and hydrogen detection schemes in a temperature range from 77 K (liquid nitrogen) to 400 K. We used e-beam deposition and low energy ion implantation for preparing our samples, and current vs. voltage electrical measurements to monitor the devices’ response to hydrazine and hydrogen. Raman spectroscopy was used for investigating the surface chemistry of the devices exposed to hydrazine at various temperatures.
3:30 PM - **V3.5
Guided Self-assembly of Nanostructured Titanium Oxide.
Baoxiang Wang 1 , Min Zhou 1 , Zbigniew Rozynek 1 , Jon Otto Fossum 1
1 Department of Physics, Norwegian University of Science and Technology, Trondheim Norway
Show AbstractElectrorheological fluid (ERF), as a smart materials, are suspensions of polarized dielectric particles in a nonconducting liquid and exhibit drastic changes in their rheological properties, which include a large increase in apparent viscosity and the formation of reversible suspension microstructures. Application of an electric field can induce polarization of the suspended particles. As a result, a chainlike structure can be formed along the electric field direction in a few milliseconds.1-5 So the shape and surface of particle may play a very important role to for the assembly of chainlike structure. Titanium oxide nanowires and nanorods are synthesized by a simple wet chemical method and characterized by the SAXS, AFM, and thermal analysis. Firstly, Tetrabutyl titanate (TBT) precursor was added to ethylene glycol (EG) and heated to form TiOx nanowires.6 Furthermore, TiOx nanorods with high rough surface can be got by hydrolysis of TBT with the help of Cethyl-Trimethyl-Ammonium Bromide (CTAB) as surfactant in EG solution. AFM results show that the nanowires are easy aggregating each other to form boudles and high rough TiOx nanorods is formed by the self-assembly of TiOx nanospheres. The electrorheological (ER) effect is investigated with the suspension of titanium oxide nanowires or nanorods dispersed in silicone oil. Oil suspensions of titanium oxide nanowires or nanorods exhibit a dramatic assembly when submitted to a strong DC electric field and aggregate to forms chains like structures along the direction of applied electric field. We have used small angle X-ray scattering to get insight into the nature of the titanium oxide nanowires and nanorods in the chains. The two-dimensional SAXS images from chains of anisotropic shape particles exhibit a marked anisotropy SAXS patterns, reflecting the preferential guided selfassembly of the particles in the field.
4:30 PM - **V3.6
Development Of Multifunctional Structural Material Systems By Innovative Design And Processing.
Hiroshi Asanuma 1
1 Mechanical Engineering Course, Chiba University, Chiba-shi Japan
Show AbstractInnovative designing concept and fabrication process to realize smart and robust structural material systems, (1) without using sophisticated functional materials (Type A) and (2) using them in a metallic matrix as a protective environment (Type B), respectively, are introduced in this paper. The Type A route can be explained as follows: There exist a couple of competitive structural materials which normally compete with each other because of their similar and high mechanical properties, and they tend to have another property which is different from each other or opposite among them. So if they are combined together to make a composite, the similar property, normally high mechanical property, can be maintained, and the other dissimilar property conflicts with each other, which will successfully generate a functional property without using any sophisticated functional materials. As successful examples of this type, Ti fiber/Al multifunctional composites and CFRP/aluminum active laminates have been developed. The second one (Type B) can be realized by embedding fragile functional fibers in an aluminum matrix by the interphase forming bonding method developed by the author, and piezoelectric ceramic fiber/aluminum composites and optical fiber sensor/aluminum composites have been successfully fabricated.
5:00 PM - V3.7
Nanoimprinting using Anodic Porous Alumina as a Mold.
Takashi Yanagishita 1 2 , Takahide Endo 1 , Kazuyuki Nishio 1 2 , Hideki Masuda 1 2
1 , Tokyo Metropolitan Univ., Tokyo Japan, 2 , KAST, Kanagawa Japan
Show AbstractThe preparation of nanometer scale structures has attracted much attention due to the utilization for various types of functional application fields. Nanoimprinting is a promising technique for the high-throughput preparation of ordered fine structures on a substrate. The molds used for nanoimprinting are usually fabricated by a combination of electron beam lithography and the dry etching. However, in these processes, it is difficult to prepare the molds with a pattern of high aspect ratios or large sizes. In our previous reports, we described the fabrication of polymer nanostructures with high aspect ratios by nanoimprinting using anodic porous alumina as a mold [1-4]. Anodic porous alumina, which is formed by anodization of Al in an acidic solution, is a promising for the molds to prepare the nanometer-scale structures with high aspect ratios and large sizes, because of its unique geometrical structures [5]. In the present report, we describe the preparation of ordered structures of inorganic materials with high aspect ratios by nanoimprinting using anodic porous alumina as a mold. In the experiment, ordered silica pillar arrays were prepared by nanoimprinting using a spin-on-glass solution. The diameter and height of silica pillars could be controlled by changing the geometrical structures of anodic porous alumina molds. The obtained silica nanopillar arrays will be applied to various types of functional nanodevices.[1] H. Masuda et al., Appl. Phys. Lett., 78, 826 (2001). [2] T. Yanagishita et al., Jpn. J. Appl. Phys. 45, L804 (2006). [3] T. Yanagishita et al., Vac. Sci. Technol. B, 25, L35 (2007). [4] T. Yanagishita et al., Appl. Phys. Exp., 1, 067004 (2008). [5] H. Masuda et al., Science, 268, 1466 (1995).
5:15 PM - V3.8
Multiple Duplication of Electroformed Nano-Ni Stamps from Si Mother Mold.
Si-Hyeong Cho 1 , Jung-Ki Lee 1 , Jung-Ho Seo 1 , Hyun-Woo Lim 2 , Jin-Goo Park 1 2
1 Bio-Nano Technology, Hanyang University, Ansan city, Gyeonggi-do, Korea (the Republic of), 2 Materials Engineering, Hanyang University, Ansan city, Gyeonggi-do, Korea (the Republic of)
Show AbstractNanoimprint lithography (NIL) is an alternative lithographic method that offers a sub-10 nm feature size, high throughput, and low cost. It requires a mold which has a low fabrication cost and long life time. A stamp is the material with various patterns to transfer on the plastic substrate. Materials such as Si, quartz, plastic and Ni have been widely used for micron or sub micron sized stamp fabrication depending on its pattern size and application. Si and quartz are very easy to be broken, and plastic can be deformed easily during process. However, Ni has high enough hardness and life time as a mold material and can be fabricated from on Si micro to nano sized molds with a seed layer by a simple Ni electro-deposition. After electro-deposition, the sample is usually dipped in KOH solution to remove Si from Ni. The consumption of Si mold is necessary step to produce a Ni stamp.In this study, a method was developed to fabricate a Ni stamp without the consumption of Si stamp. Vapor SAM (self assembled monolayer) method was used to deposit hydrophobic layer on Si mold. A low surface energy release layer on stamp surfaces not only helps to improve imprint qualities, but it also increases the stamp lifetime significantly by preventing surface contamination. Hydrophobic layer, which has a low surface energy, makes possible to separate Ni from Si substrate without causing any damages on Si stamp. The characteristics of deposited hydrophobic layer were analyzed by measurements of the contact angle, its hysteresis, surface energy, thickness and lateral friction force. The stiction of Ni on Si mold was observed when the separation of Ni from Si was tried without the SAM deposition.The multiple duplication of Ni stamps has been successfully developed without disposing costly Si mother stamp. Duplicated patterns on Ni stamp showed the same patterns as on Si mother mold when they were observed with optical microscope, FE-SEM, and AFM (atomic force microscope).
5:30 PM - V3.9
A Novel Technique for the Nano-fabrication of Diamond Stamp Structures.
Warren McKenzie