You are browsing the archives of 2009 October.

Nanogenerator. (Credit: Georgia Institute of Technology)

Via press release from University of Wisconsin, we learn that a team of researchers has developed a piezoelectric nanogenerator and experimented with a variety of materials to power it.

The team found that zinc oxide nanowires, which have six-sided, column-like crystals, could produce 10 nanowatts per square centimeter by converting mechanical energy into electricity. The mechanical energy could come from environmental sources as varied as wind, car engines, human breathing, blood flow, body movements, or acoustic and ultrasonic vibrations.

Unfortunately, the zinc oxide nanowires had a low efficiency rate. Xudong Wang, associate professor at U-W, is tackling this challenge by researching a new material that could make the nanogenerator more efficient and powerful. An optimized nanogenerator could power small devices with a wide range of applications, such as LEDs, transistors and biomedical devices.

Wang is developing ferroelectric materials that could produce nanowires with 10 times the electric potential of the original zinc oxide ones. The increase occurs because the crystal of a ferroelectric material is made of spatially unbalanced atoms that produce automatic, permanent polarization in the material. When Wang introduces strain inside this unbalanced crystal, the polarization is enhanced, creating a significant amount of electric potential.

Wang’s theory is that very little mechanical energy would be needed to power the new nanogenerator because even a small amount of displacement has a larger effect on nanoscale materials.

“We are currently investigating how much potential can be generated by such nanowires when they are deflected using atomic force microscopy,” Wang says.

Wang’s ultimate goal is to make a real nanogenerator capable of powering a variety of small devices. Since the generator would require such a small amount of power from sources that are continuously providing energy, it could serve essentially as an eternal battery.

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A team of engineers at North Carolina State University has created a small chip that can hold 1TB of data. That’s over 50 times the capacity of today’s silicon-based chip.

Led by Jagdish “Jay” Narayan, director of the National Science Foundation Center for Advanced Materials and Smart Structures at NCSU, the team said that their nanostructured Ni-MgO system can store up to 20 high-definition DVDs or 250 million pages of text.

Working at the nanoscale, the engineers added metal nickel to magnesium oxide. The resulting material contained clusters of nickel atoms no bigger than 10 square nanometers. The discovery represents a 90 percent size reduction compared with today’s techniques, and an advancement that could boost computer storage capacity. Underlying this is the team’s discovery that under certain conditions the Ni-MgO system behaves as a perfect paramagnet.

“Instead of making a chip that stores 20 gigabytes, you have one that can handle one terabyte, or 50 times more data,” Narayan said.

This material might also open new doors for boosting vehicles’ fuel economy and reducing heat produced by semiconductors, with fuel economy potentially achieving 80 miles per gallon. The process would allow them to develop a new generation of ceramic engines able to withstand twice the temperatures of normal engines.

Narayan said that by using the process of selective doping, the engineers could introduce metallic properties into ceramics.

Selective doping also advances knowledge in the field of spintronics. The nanomaterial was manipulated so the electrons’ spin within the material could be controlled, which could prove valuable to harnessing the electrons’ energy. The ability could be important for engineers working to produce even more efficient semiconductors.

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MS&T’09 is 95 percent pure science. The other 5 percent is designed to be on the lighter side. For example, the student mug drop and putting contest are always big draws on the expo floor. Rustum Roy, too, has promised to bring “The ExperiMentalist” to the ACerS Annual Banquet.

And, this year there is some art being added the meeting events. Arun Wagh, chair of the ACerS Art Division, has organized a display at MS&T’09 featuring ceramic art pieces made by graduate students in the Alfred University Division of Ceramic Art. Various sculptures and ceramic vessels will be on display Tuesday, Oct. 27, and Wednesday, Oct. 28, in the Expo Hall at the Convention Center. Two MFA students from Alfred will be there to answer questions and talk about their work. Look for the display at the entrance to the Expo Hall. Please stop by to take a look and support the student art program as well as the Society’s Art Division.

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ACerS member Jeffrey Wadsworth has just been named the winner of the National Materials Achievement Award from the Federation of Materials Societies (of which, ACerS is a member).

Wadsworth, president and CEO of Battelle Memorial Institute, will receive the award in formal ceremonies at the National Press Club in Washington, DC, on Dec. 9, 2009.

But, ceramists and others in the materials science community will get a chance to hear Wadsworth next Monday (Oct. 26) when he delivers the keynote address at the opening session at MS&T’09 taking place in Pittsburgh, Pa. His presentation is titled, “Forging the Solution to the Energy Challenge: The Role of Materials Science and Materials Scientists.”

Besides being an expert in superplasticity in materials, Wadsworth has long been a major player in national science and technology policy, particularly in how materials science and engineering can further national goals, particularly in energy, defense and security, and workforce development for the 21st century.

Under Wadsworth, Battelle has continued to be a leading research and development organization with a $5 billion R&D portfolio and a workforce of 21,000. Before joining Battelle, Wadsworth managed a number of federal labs and programs including a stint as the director of Oak Ridge National Laboratory and deputy director for science and technology at the Lawrence Livermore National Laboratory. Wadsworth also worked as department manager at Lockheed Missiles & Space Company. He has also taught at Stanford University, the University of California Davis, University of Tennessee and The Ohio State University.

Wadsworth has been the author or co-author of nearly 300 peer reviewed scientific articles. He holds four patents and has authored one book, Superplasticity in Metals and Ceramics. He is an active member of the National Academy of Engineering and also serves the National Competitiveness Council. Besides ACerS, his professional memberships include TMS, ASM International, American Association for the Advancement of Science and Materials Research Society.

Besides ACerS, FMS members include the American Association for Crystal Growth, American Chemical Society, American Physical Society, American Welding Society, ASM International, The Electrochemical Society and The Minerals, Metals & Materials Society.

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Team Germany's window louvers with integrated thin-film CIGS cells. (Credit: Stefano Paltera/DOE Solar Decathlon)

Team Germany!

Team Germany won first place in the 2009 Solar Decathlon by applying photovoltaics to every available surface. I had been rooting for Virginia Tech for their use of aerogel as insulation that allowed natural light to shine through, but it only ranked 13 out of 20 competitors.

Team Germany’s Cube House was considered the most technologically advanced.

On the roof: a 11.1 kW photovoltaic system of 40 monocrystalline silicon panels. On the sides: 250 thin-film panels that look like glossy clapboards. The thin films used copper-indium-gallium-diselenide layers.

The combination system was expected to produce 200 percent of the energy needed by the house. The thin film panels, while less efficient than conventional silicon, were projected to perform better in cloudy weather than silicon.

Team Germany got its proof on the competition’s fifth day when skies turned slate gray and a cold rain splattered the solar village. By late afternoon, as federal commuters started streaming home and electricity demand throughout the city began climbing, the Team Germany house was producing 12.68 kW and consuming 12.33 kW, for a net export of .35 kW. Net production also occurred on two other rainy days.

Team Illinois’ house finished a close second, emphasizing energy efficiency over power production.

“Team Germany built a gingerbread house packed with solar panels,” said Richard King, DOE Solar Decathlon director. “In the rain, the thin-film panels were making electricity. It made the difference.”

Each team actually was graded on 10 criteria:

• Architecture
• Market Viability
• Engineering
• Lighting Design
• Communications
• Comfort Zone
• Hot Water
• Appliances
• Home Entertainment
• Net Metering

Team Germany was the only team to score a perfect 150 points out of a possible 150 in the net metering category, for having produced more electricity over the entire two-week testing period than it consumed. The DOE gave the Net Metering the highest weight in the contest, and each of the other categories received 75-100 possible points each.

The University of Minnesota entry was winner in the Engineering category and ranked 5th overall.

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