ENGINEERING PHYSICS

Big discoveries on a small scale

Robert Carpick and Wendy Crone

Robert Carpick and Wendy Crone (Large image)

ASSOCIATE PROFESSORS Rob Carpick and Wendy Crone could place hundreds of thousands of nanoparticles onto the period at the end of this sentence. And while the materials they study are on a tiny size level called the nanoscale, the potential for their application is huge — in everything from denser computer memory to more efficient engines.

Carpick studies friction, adhesion and wear of nanoscale materials. With Department of Energy (DOE) funding, Carpick, Professor Mike Plesha and researchers at Sandia National Laboratories are investigating the fundamental issues of friction in micromachines, which fail prematurely due to friction and wear. In another project funded by the Air Force Office of Scientific Research (AFOSR), Carpick, Assistant Scientist Anirudha Sumant, Research Professor Kumar Sridharan, Physics Professor Gelsomina De Stasio and colleagues at Sandia and Argonne National Laboratory are focusing on novel forms of diamond. “We're finding that with nanostructured diamond, nanoscale friction and adhesion can be far lower than silicon, and that makes it a promising material for nanotech applications,” says Carpick.

Crone is working with Materials Science and Engineering Professor John Perepezko and Chemistry Professor Arthur Ellis to develop methods to create active components and materials for microscopic structures and miniaturized devices, and experiments to characterize, understand and optimize their behavior. With support from the AFOSR and DOE, they build new nanostructured materials particle by particle. To make their work easier, members of the research group devised a method that enables them to easily manipulate nanowires magnetically. In a related project, they are developing nanostructured materials — in particular, shape-memory alloys — and trying to understand how their particle or grain size is affected by the nanoscale.

Together, Carpick and Crone share teaching duties in a new course for undergraduate and graduate students devoted entirely to micro- and nanotechnology and have been instrumental in creating a vision for the nanoengineering specialty area of the department's new bachelor of engineering physics degree.

Burning issue:
New organization energizes plasma researchers

THE U.S. DEPARTMENT OF ENERGY Office of Fusion Energy Sciences has named Steenbock Professor Ray Fonck head of a group that will rally burning-plasma researchers around the country.

With plans progressing for ITER (the international thermonuclear experimental reactor), the U.S. Burning Plasma Organization will coordinate and establish teams of American scientists to work in burning-plasma research areas of focus, says Fonck. In addition, it will position those scientists to compete for research time at the international level.

The United States' share of ITER's construction cost will be about $1 billion. Not only will the new organization involve and integrate researchers from around the country, but it also demonstrates the country's scientific ownership of burning-plasma research, says Fonck.

Divisions within the U.S. Burning Plasma Organization will help organize research in specific scientific topic areas, suggest research directions, and bid for time on the U.S. experiments. Frequent communication among participants will help identify the highest-priority activities and then relay those judgments to funding agencies. The result, says Fonck, will be a virtual laboratory of burning-plasma scientists working toward common goals.

Fuel for the future:
Finding the best materials for Gen IV reactors

USING SOME CURRENT NUCLEAR REACTOR MATERIALS in the high-temperature, high-pressure reactors of tomorrow is a little like trying to cook a steak with a flamethrower. The operating environments are so extreme that both the reactor materials — and your dinner — would fail.

One reactor concept under a new U.S. Department of Energy (DOE) nuclear energy initiative is the supercritical water reactor (SCWR), which combines high pressure and high temperatures to convert water into its supercritical state. This super-heated water drives a turbine and a generator that convert the heat into more electricity with the same amount of fuel as current reactors.

But the high temperatures and pressures also pose materials challenges. With funding from the DOE Office of Nuclear Energy, Science and Technology, Assistant Professor Todd Allen and Research Professor Kumar Sridharan are studying ways to improve materials for fuel containment and other components in SCWRs.

They have identified ferritic martensitic steels and austenitic steels as good prospects. For the ferritic martensitic steels, they are trying to find ways to make the oxide (rust) layer thinner, yet keep it stable; for the austenitic steels, they hope to keep the oxide layer thin, yet make it more stable. They are also testing a variety of chemical and physical surface treatments to find the right combination of oxide layer and stability.

These materials also are candidates for other proposed reactors, including lead-cooled and molten-salt reactors. The researchers' new laboratory, the Extreme Environment Laboratory, built in part by Associate Scientist Mark Anderson, will give them the unique capability to study how materials perform across the proposed reactor systems.

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