UI Researchers Miniaturize Mechanics, Materials in Nanodevices

Released: 8/25/2004 9:10 AM EDT
Source Newsroom: University of Idaho
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Newswise — Nanoparticles and nanodevices -- a thousand times smaller than a human hair (about a millionth of a meter) -- are becoming part of such commonplace products as stain-resistant fabrics, sunscreen, tennis balls and bathroom tile cleaner. Just around the corner will be the use of nanotechnology for air purification systems, medical sensors, imaging devices, processed foods, fuel cells, electronics and other such modern tools.

While microchips and nanochips now are manufactured by the millions for computing use, lesser-known applications of nanomechanisms and materials are in the making as well. A cluster of University of Idaho researchers now lays the groundwork for Idaho and the nation to bring these miniscule technologies to industry and the marketplace. They are perfecting wires, rods and springs of nanoscale proportions (approximately one-billionth of a meter) and are developing processes to fabricate electronic, optical, biological and magnetic nanomaterials.

Their research is funded by the federal government, non-profit foundations and the private sector. The National Science Foundation's Experimental Program to Stimulate Competitive Research (EPSCoR) and the Keck Foundation are major supporters of advancing nanoscience and its commercial applications in Idaho.

"The University of Idaho has developed a focal research group to address nanotechnology and its capabilities for faster, cheaper, more efficient and environmentally friendly engineered products," said Charles Hatch, UI vice president for research. "UI researchers now can fabricate tiny tubes that self-assemble and can be coated in metal to form highly conductive wires and springs smaller than 100 nanometers."

Other UI products:

· Nanowires and nanorods are ready for industrial use as catalysts, in sensors and semiconductor devices, or as contrast agents in magnetic resonance imaging and xerography. The mini-shapes are grown by a process called "supercritical fluid (SCF) methods," by which multi-walled carbon nanotubes are used as templates, and the resulting metallic nanowires take the form of the inner cavity. The process produces more uniform and homogenous nanoparts faster. It enhances permeation, diffusion and penetration of small areas, complicated surfaces and drier substrates. Also, some SCFs, such as supercritical carbon dioxide, leave no solvent residue and are recyclable. Contaminants can easily be removed from the system leaving purer products.

· Nanosprings, a form of coiled nanowires with potential application in nanoelectronic and nanomechanical systems, have been produced by UI researchers using boron carbide, silicon carbide and silicon dioxide. They are grown by a process in which a liquid metal droplet (catalyst) absorbs material from a vapor. Once the concentration of the building block material becomes supersaturated, the excess material is expelled from the base of the catalyst where it solidifies into a nanowire, which can be coiled.

· Nano-composite catalysts are formed using metals and alloys deposited as nanoparticles on nanotubes and nanowires or are dispersed in a polymer or plastic. The nanoparticles are stabilized to prevent lumping and thereby reduce the need for expensive platinum group metals. These catalysts can be used in a variety of chemical processes including hydrogenation, oxidation and fuel cell applications. The high catalytic activities of nanometer-sized metal particles appear promising for many industrial and environmental applications. Catalytic activity, recyclability, and ease of separation from the catalyst improve the process and performance.

· Pac-Man, a new magnetic nanotool, will play a critical role in magnetic random access memory (RAM) products, magnetic sensors, recording heads and patterned high-density magnetic recording media. The Pac-Man tunneling junctions are formed by such materials as cobalt, nickel or iron, among other materials, and their design overcomes the limitation to size reduction; particularly, the loss in performance when the technology shrinks to the nanoscale for the purpose of increasing memory size.

The researchers and the Idaho Research Foundation can assist Idaho's industries with nanoscience materials development and troubleshooting. The above patent-pending technologies also are available for commercial licensing.
The research teams include David McIlroy, physics professor who discovered a process for synthesizing nanosprings; Chris Berven, physics expert in advanced nanodevice fabrication; and Eric Aston, chemical engineering professor and expert in mechanics at the nanoscale.

Professor Gregory Bohach, microbiologist, focuses on the biological applications of nanoscience; Pamela Shapiro, is an expert in chemical bridges between nanowires and biological sensors. Chien Wai, chemistry professor, and his team invented nanocatalysts for reactions in supercritical carbon dioxide. Yang-ki Hong, materials science engineer, is involved with semiconductor fabrication and nanopartical deposition.

For more details, contact the Idaho Research Foundation, Inc., (208) 885-4550, irf@uidaho.edu.


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