2006 MRS Spring Meeting Scene - Day 3

MRS Meeting Scene
Day 3 — Wednesday, April 19, 2006
Daily dose from San Francisco. Bringing you the very best of MRS.

The third day of the 2006 MRS Spring Meeting was a busy one for attendees, and was highlighted by the Plenary Session in the evening that included the plenary presentation by Craig Barrett, CEO of Intel. Other significant events included the Outstanding Young Investigator talk by Ju Li, the second day of poster presentations, the Science as Art competition, and the second day of the exhibit.

"The world is always ready to receive talent with open arms."
Chef Chu Restaurant, Los Altos, CA, circa 2000
Fortune cookie message, quoted by Dr. Craig Barrett, Plenary Speaker, who carries it in his wallet

"There is a world of wonder and a bright future for students of mechanics and physics of materials."
Ju Li, 2006 MRS Outstanding Investigator Award recipient

Plenary Session

The major event of the day was the Plenary and awards session held in the evening. 2006 MRS President Peter Green welcomed attendees to the session and stated that the current meeting was very successful on many levels, including a 10% increase in the number of attendees (over 3,300) compared to last year, which is a record for an MRS spring meeting. Past-President Dave Eaglesham acknowledged and thanked the meeting Chairs J. Charles Barbour, Paul S. Drzaic, Gregg S. Higashi and Viola Vogel for their efforts.

Secretary Cynthia Volkert then announced the Graduate Student Gold and Silver Award winners. The students had presented their research to a panel on Tuesday. Finally, President Green presented the Outstanding Young Investigator award to Ju Li (Ohio State University).

Plenary Talk

The Digital Evolution
Craig Barrett, Chairman of the Board for Intel Corporation, gave an extraordinary Plenary talk to an 800 plus-strong audience on how technology continues to impact our evolving digital world. Barrett, who holds a Ph.D. in materials science and engineering from Stanford University, described the tremendous impact that the digital revolution has had in the past four decades, and will continue to have in the foreseeable future. It has become an engine of change from a global perspective, and over the past ten years has brought 3 billion people from emerging economies of the world into its fold. He demonstrated how Moore's law continues to hold true after 40 years and will likely do so over the next 15 years at least. However, newer technologies and paradigms are emerging, such as nanotechnology and molecular electronics, that will lead the path away from the traditional CMOS technologies used in silicon microelectronics.

Barrett described how the ever-growing computational power will transform our lives, and new applications will be able to use this power, thereby enriching our lives. New emerging areas include user-aware computing wherein a computer will be better able to sense our thoughts and needs, and respond accordingly. He showed a video of the recent DARPA grand challenge car race, wherein the cars had to travel 200 miles entirely under the control of computers and with no human intervention. A car from Stanford Univ. won, and four other cars completed the course successfully. He also described a new techology called Claytronics that can create snynthetic reality.

Finally, Barrett spent some time discussing the K-12 education system in the United States. In the U.S., data show that students fall behind their peers in other countries particularly in science and math at the high school level. This does not bode well for technological progress in the country. He concluded by reiterating that nothing beats investing in good people and ideas for successful organizations such as Intel. Rules can and should be changed, and the industries that resist change will be in trouble. Barrett then participated in a lively question & answer session with the audience.

OYI Talk: The Mechanics and Physics of Defect Nucleation

Earlier, Ju Li presented his OYI presentation as part of symposium Z on the Mechanics and Physics of Defect Nucleation. Defect nucleation plays a critical role in the mechanical behavior of materials, especially if the system size is reduced to submicron scale. At the most fundamental level, defect nucleation is controlled by bond breaking and reformation events, driven typically by mechanical strain and electronegativity differences. For these processes, atomistic and first-principles calculations are uniquely suited to provide unprecedented level of details. Several connecting threads incorporating notions in continuum mechanics and explicit knowledge of interatomic energy landscape can be identified, such as homogeneous versus heterogeneous nucleations, cleavage versus shear-faulting tendencies, chemo-mechanical coupling, and the fact that defects are singularities at the continuum level but regularized at the atomic scale.

Li presented a number of examples chosen from nanoindentation, crack-tip processes, and grain boundary processes. Besides identifying candidate mechanisms, ideal strength, activation energy and activation volume are quantitative information that the calculations can provide to validate against experiments. One example described by Lee was stress corrosion cracking of silica by water, wherein at low stress levels, chemical attack leads and mechanical effects follow. At intermediate stress levels, mechanical and chemical effects are similar and neither dominates. At high stress levels however, mechanical effects lead while chemical effects follow. Finally, Li reiterated that there are a number of things to be discovered in mechanics and physics of materials, and there is a bright future for students in this field.

Molecular dynamics simulation of nanoindentation in aluminum thin film demonstrates the nucleation and evolution of dislocations that mediate plastic deformation in crystalline solids. In this image, dislocations nucleated under the nanoindenter first entangle, which under further applied load emit highly mobile prismatic dislocation loop gliding through the crystal. The correlation of these simulations with actual experiments enables prediction of the exact location and character of homogeneously nucleated defects under large strain, an issue of fundamental importance for understanding incipient plasticity, phase transformation and fracture in materials. (Courtesy Ju Li, Ohio State Univ.)

Symposium X - Frontiers of Materials Research

Risk Assessment of Nanotechnology
The three-part forum of Wednesday’s Symposium X featured a cell biologist, a physiologist, and a chemist speaking about various aspects of the risks of nanotechnology to humans.

Harald F. Krug of the Forschungszentrum Karlsruhe in Germany spoke first on “Health Aspects of Nanoparticles: In Vitro Testing of Toxicity.” He pointed out that many products containing nanoparticles already exist on the market, including sunscreens, cosmetics, pharmaceuticals, copier cartridges, and additives for polymers and scratch resistant coatings. In contrast to such mundane applications, the media presents nanotechnology in terms of fantastic visions, such as molecular robots crawling through our bloodstreams and killing all the germs.

As a cell biologist, Krug is concerned with toxicological risk assessment. There are two prerequisites for a risk: there must be (1) an exposure and (2) a hazard. But identifying hazards is not easy. The questions include whether the substance makes it into the food chain, whether it can accumulate in our bodies, whether it has surface reactivity, whether it is metabolized, and whether it interacts with the ecosystem, among others. To answer these questions requires research into nanoparticle uptake by cells, accumulation of nanoparticles in cells or organs, effects of inhalation of nanoparticles into the lungs, etc.

Studies using an in vitro system called the 3D Cell Model, which combines an aerosol of nanoparticles in a container with macrophages, epithelial cells, and endothelial cells in a biological medium, have shown that nanoparticles can invade epithelial cells, pass through a membrane, and then attack the endothelial cells on the other side. While other research efforts in both in vitro and in vivo systems are taking place around the world, Krug said that they are being done with nanoparticles of varying properties, making them difficult to compare. Standards processes and materials are needed to make significant advances in the field.

Vincent Castranova, a physiologist from the National Institute for Occupational Safety and Health (NIOSH), presented details of research on “Pulmonary Toxicity of Single Walled Carbon Nanotubes.” The research studied laboratory mice that had aspirated a drop containing single walled carbon nanotubes (SWCNTs) into their lungs. They were examined for lung damage, inflammation, oxidation stress, and the presence of fibrosis over the course of 1 to 60 days. Initial results showed dose-dependent levels of damage, oxidation stress, and inflammation that peaked within a few days of exposure, then returned to normal. From this assessment, Castranova said, it appeared that inhaled SWCNTs were non-toxic to mice. However, further studies showed significant fibrosis occurring even in the absence of inflammation—an unusual pattern. Also, SWCNTs aggregated in clumps in the lungs. Control mice which had aspirated carbon black showed no such fibrosis, indicating the SWCNTs were the source of the damage.

Finally, chemist Stefan Engel of the Hazardous Chemicals Management division of BASF in Germany spoke on “Occupational Hazards Dealing with Nanomaterials.” While his studies show that dermal exposure to engineered nanoparticles in the workplace is probably not hazardous, inhalation exposure clearly can be, depending on the chemical, physical, and geometric properties of the dust. He detailed the major initiatives being carried out in Europe and the rest of the world to better understand the effects of nanoparticles on human health. At BASF, he said, the policy is to communicate to workers openly and in a well-balanced way the possible risks and hazards they may face in the workplace.

Poster Award Winners

P8.23
Electronic Interface Between Nanowires and Neurons
Brian P. Timko¹, Fernando Patolsky¹, Guihua Yu¹, Andrew B. Greytak¹ and Charles M. Lieber¹,² ; ¹Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts; ²Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts.

P8.27
Strained Silicon Nanowire Field Effect Transistors by Bottom-up Device Integration
Rongrui He¹, Alvaro San Paulo², Di Gao³, Carlo Carraro³, Roya Maboudian³, Jeffrey Bokor² and Peidong Yang¹; ¹Chemistry, Univ. of California, Berkeley, Berkeley, California; ²Electrical Engineering and Computer Sciences, Univ. of California, Berkeley, Berkeley, California; ³Chemical Engineering, Univ. of California, Berkeley, Berkeley, California.

U7.36
Integration of Single-Walled Carbon Nanotubes with III-V(110) Surfaces
Laura Ruppalt¹,² and Joseph W. Lyding¹,² ; ¹Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois; ²Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois.

Technical Talks

Controlled Growth of Oxide Nanostructures
Nanobelts, nanosprings, nanorings, nanobows, nanohelices, and nanospirals: all these morphologies can be grown in a catalyst-free, single-step thermal evaporation process from ZnO, as reported by Zhong Lin Wang of the Georgia Institute of Technology. The driving force behind the formation of these shapes is the polar surface of ZnO; curling into circular or helical structures reduces the dipole moment of the structure. Simultaneously, the elastic energy of the system competes with the dipolar energy to determine the equilibrium structure.

Courtesy Z.L.Wang (Georgia Tech)

Of particular interest are the nanohelices, which can adopt left or right handed conformations. Wang reported that these helices contain superlattices consisting of two stripes of the same material with different ordering parameters. One stripe has a polar surface and the other a non-polar one. This superlattice forms spontaneously when mismatch dislocations appear in the crystal.

These shapes are grown in a freestyle mode, with no catalyst present; a gold catalyst would selectively nucleate nanorods or nanowires. By controlling the pressure of the system during crystal growth, Wang and his colleagues can substantially control the yield of a desired morphology. Such control could prove to be significant in future applications of these ZnO nanostructures, which are optically transparent, piezoelectric, pyroelectric, and biocompatible.

Breaking the Nanometer Barrier in Single Molecule Studies—or—How a Biophysicist Watches DNA Transcription
In a very entertaining and important symposium AA talk entitled “Breaking the Nanometer Barrier in Single Molecule Studies—or—How a Biophysicist Watches DNA Transcription,” Steven M. Block of Stanford University detailed his group’s work in understanding the operation of the RNA polymerase enzyme in reading and transcribing DNA. The work has been so successful that they can read the DNA sequence as fast as transcription takes place. Block and his colleagues designed an ultra-low noise optical trap for the work. This involved replacing the air in the system with helium to reduce laser distortion due to refraction, and designing a novel force clamp that permits angstrom-level measurements to be made with confidence.

Using this new optical trap, the researchers were able to watch RNA polymerase “walk” along a DNA molecule at 1 angstrom per second in real time in an aqueous solution at room temperature. They could see in previously-impossible detail each base-pair step the RNA polymerase made along the DNA molecule, including the pauses and the backtracking that occur periodically when the RNA polymerase makes a mistake in transcription and goes back to fix it. The accuracy of the real-time sequencing of DNA was confirmed by an experiment in which 29 of 30 DNA bases were correctly identified in about a minute of data collection time.

Self-Assembly of Biomimetic and Bioactive Nanostructures
One-dimensional nanostructures are important because they can be used to connect points by self-assembly, they may align in external fields, and they can form fibrils and networks to mimic biological extracellular matrices. In his presentation entitled “Self-Assembly of Biomimetic and Bioactive Nanostructures,” Samuel I. Stupp of Northwestern University said that we need to develop “codes” to control the shape and function of such nanostructures.

One such code that his group has developed is for helix formation. Helices occur extensively in nature over a range of scales, from DNA strands down to viruses. While we are not sure why they are so prevalent, it is clear that learning to control the properties of self-assembled helices is a necessary step in biomimetic engineering. Stupp and his group have learned how to control the pitch of a helix by controlling the torque on a molecular cylinder through addition of chemical substituents to amphiphiles. Starting with a peptide lipid cylinder, they substituted increasingly bulky organic functional groups for hydrogen atoms. These substituents create steric hindrance, and the axis of the cylinder coils to minimize elastic energy. Using benzophenone as a terminal substituent, the researchers were able to produce a helix with a pitch of 90 nm. Adding another methyl group to the benzophenone reduced this to 60 nm—a tighter spiral. Stupp showed how his group could produce helices having pitches from 160 nm down to 24 nm by judicious choice of bulky organic groups. This type of structural control has not been demonstrated before.

Beyond helices, Stupp showed how the self-assembly of peptide amphiphiles with a hydrophobic tail and a bioactive head group could lead to the spontaneous formation of bioactive nanofibers with signal displays on the surface. In one case they produced a nanofiber with the IKVAV epitope on the surface, which caused neurons to sprout neurites in a biological system. Other bioactive fibers succeeded in promoting blood vessel growth in the eyes of laboratory rats. Finally, Stupp demonstrated how self-assembled nanofibers might also be used as biological sensors. By creating a molecule with a hydrophobic tail made of a conductive polymer and a head made of peptides, a nanofiber with a conductive polymer core and a protein-sensitive surface might be produced. Such a fiber could possibly transmit minute electrical changes through its conductive core caused by surface changes due to adsorption of target molecules, thus making it an effective biological sensor.

Women in Materials Science & Engineering Breakfast

Women in Science and Engineering Careers: Harnessing Our Strengths for the Long Haul
“If you are miserable, it’s not you . . . it’s where you are.”
Find a different job that fits. That was Merrilea Mayo’s advice to the crowd of mostly woman and some men at the Women in Materials Science and Engineering breakfast. Currently, Mayo is a director of the Government–University–Industry Research Roundtable at The National Academies. As a person interested in everything, but often bored with anything in 5–7 years, Mayo calls herself an expert at how to move from one thing to the next. She moved from metallurgy to ceramics, and now to policy. Indeed, she even said she is good at firing, because she can see when someone else does not fit and would be in a better situation doing something else. The session focused on Women in Science and Engineering Careers: Harnessing Our Strengths for the Long Haul. Mayo gave humorous and insightful hints into how to avoid bad jobs and find a dream job. She said, “If you wouldn’t want to have lunch with your interviewer, run the other way, but more importantly make sure your values match those of the people and institution you are joining.” If it is not the right match, wait for the next one, or create it, she said.

Nancy Yang, Distinguished Member of the Technical Staff at Sandia National Laboratories in California, said that it is not necessary for women to act like their male counterparts in order to succeed. Women need to emphasize their own strengths. Instinct, common sense, and attention to detail are some talents Yang had found can be a benefit in team-building. Having entered the field in mining and metallurgy at a time when she was not allowed in the mine pit because it was considered bad luck for a woman to be there, she said, “We have come a long way.”

While a significant fraction of people in the audience still felt they were treated differently because of their gender, several audience members said that now gender seemed like less of a problem than cultural differences due to misunderstandings about customs and expectations. Mayo said that facilitators can help with such cultural differences.

Linda Vanasupa of California Polytechnic State University moderated the panel, which was sponsored by the MRS Public Outreach Committee, FEI Company, and Sigma-Aldrich.

Nanoscale Informal Science Education (NISE) Activities

The S2006 Meeting was the first to play host to a set of activities to publicize the Nanoscale Informal Science Education (NISE) Network. The NISE project is a $20M NSF funded outreach effort to help shape the national public discourse and understanding of nanotechnology. It is led by three of the Nation's leading science museums: Museum of Science in Boston, the Exploratorium, and the Science Museum of Minnesota.

MRS has the lead responsibility for building a network of research scientists who will serve as subject area experts for the science museums. These experts will review scientific content, provide technical oversight and advice on NISE projects and activities. They may also participate in the NISE products, such as tools for Informal Science Education (ISE) training.

The focus of NISE during the first two years of the project will be on developing the best approaches to engaging public audiences in understanding and discussing nanoscale science and engineering themes and perspectives. This will be accomplished through the development of a wide variety of prototype exhibits, programs, media, and professional development activities. The focus during subsequent years will be on the production, implementation, and dissemination of educational and professional development activities and materials.

At S2006, NISE activities were located near the other MRS outreach venues and included:

• The very popular Visualization Lab area, led by an Exploratorium team, where scientific artists brainstorm with MRS meeting attendees to develop visual renderings of nanoscale landscapes
• Exhibit prototype elements from the Exploratorium , Oregon Museum of Science & Industry, Children’s Museum of Houston and the University of Wisconsin-Madison MRSEC
• A video on NISE Network and ISE produced by the Science Museum of Minnesota
• The MRS NISE functional area at which bookmarks and fact sheets to publicize the Network program were distributed
• An on-line science advisor registration survey to build an MRS volunteer database for NISE
• Sign-up table for the Nanoscale Education Outreach program, an ISE tool development program designed for graduate students, post docs and research center education directors
• An MRS NISE Subcommittee meeting also attended by members of the Exploratorium

In addition, presentations about the NISE network were given as part of Symposium KK, at the University Chapters Luncheon, and immediately following the Tuesday evening presentation by the NSF.

Exhibit Experience

New Type of Low Energy Electron Microscope (LEEM) Now Available at SPECS
A next generation Low Energy Electron Microscope with unsurpassed 5 nm resolution for dynamic LEEM Microscopy experiments is now available from SPECS GmbH, Berlin. With this instrument, based on the design of Dr. Rudolf Tromp, nanometer scale processes on surfaces can be made visible in real-time. Low Energy Electron Microscopy is a key technique for research in the field of surface dynamical processes. In a LEEM, electrons are slowed down to energies of not more than several ten eV before they interact with the sample. This allows in situ observation and analysis of surface processes. For more information, visit SPECS at Booth 335 and attend our talk at the Exhibitors Spotlight on Tuesday, April 18, at 5PM.

SURFACE presents the new HRLH-140 Laser heating system
This new heater concept works independent of it‘s environment--at any pressure, any gas and has an wide temperature range. The light fiber coupled optical head includes a single- or dual-wavelength pyrometer. A built in embedded RT-Linux PC is sampling the pyrometer with 10 kHz and handle datalogging, what allows high speed control to run temperature ramps extreme precisely up to 600°C/sec and higher, based on material. Stop by Booth 312 for additional information or contact us at www.surface-tec.com.

Varian's VS Series Leak Detectors: Press Test, Get Power
VS Series leak detectors combine the simplicity of two-button operation with advanced system intelligence. Start and Vent pushbuttons permit extremely simple day-to-day operation, while providing intuitive navigation, allowing easy access to vast system capabilities. Programmable test sequences minimize operator error, and maximize production efficiency. The high definition touch screen display offers the operator a wide range of languages and units of measure for worldwide usage. Contact Dave Nordquist at dave.nordquist@varianinc.com for more information. Please visit us at Booth #217 or on the Web at http://www.varianinc.com/vsseries/.

Veeco, Booth 407—The new GEN20 MBE System: application specific designs, optional unattended operation. This all-new model, in a proven platform, manufactures wafers up to 4” with multi-chamber processing capabilities. It seamlessly integrates application-specific design features for both existing and emerging materials, including nitrides and oxides. Available either in automated cluster tool or manual models, the GEN20 provides flexible solutions for R&D and pilot-production. For more information visit http://www.veeco.com/gen20 or call 1-888-24-VEECO.

WITec Introduces the Alpha300 Microscope Series
WITec has launched a new modular microscope generation, the alpha300 series featuring Confocal Raman Microscopy, NSOM, and AFM. The revolutionary system-on-a-chip concept of the new microscope’s control unit alphaControl enhances not only user friendliness but also speed, flexibility, accuracy and expandability. It enables various new features and automatic measurement procedures to be employed for the first time. The digital signal processing reduces noise to extremely low levels and significantly enhances data and image quality. Stop by Booth 512 for additional information or contact us at harald.fischer@witec.de or http://www.witec.de/company/archive_26.html.

miniDAWN TREOS Multi-Angle Light Scattering Detector
Wyatt Technology Corporation presents the miniDAWN TREOS Multi-Angle Light Scattering (MALS) Detector at Booth 425. The TREOS represents a major advancement in the sensitivity and dynamic range in measurements of multi-angle light scattering (MALS) for small molecules. It has over twice the signal-to-noise ratio and 100x the dynamic range of the previous generation of miniDAWN instruments, allowing measurements of smaller molecules at lower concentrations than ever before! For more information, email info@wyatt.com or visit www.wyatt.com.

Sonics and Materials introduces their latest Ultrasonics Catalog
This catalog contains valuable information on the theory of ultrasonic liquid processing, instrument selection criteria, and answers the most commonly asked questions about ultrasonic processing. These instruments can safely process a wide range of organic and inorganic materials, from microliters to liters. Typical applications include dissolution, sample preparation, extraction, homogenization, and particle size reduction. For more detailed information, please visit us at booth 322 or www.sonics.biz.

• Compiled and edited by Gopal Rao, MRS Web Science Editor with contributions from Betsy Fleischer, Tim Palucka, Ed Stiller, Kristin Wilson and Donna Watterson
• Comments and feedback are welcome
• To Subscribe or Unsubscribe, please visit the MRS e-newsletters/alerts page
• 2006 MRS Spring Meeting website

© Materials Research Society, 2006