A group led by Jillian Buriak has found a rapid and cost-effective method of forming tiny particles of high-purity metals on the surface of advanced semiconductor materials such as gallium arsenide. While the economic benefits alone of such a discovery would be good news to chip manufacturers, who face the problem of connecting increasingly tiny computer chips with macro-sized components, the group has taken their research a step further.
The scientists also have learned how to use these nanoparticles as a bridge to connect the chips with organic molecules. Biosensors based on this development could lead to advances in the war on terrorism.
"We have found a way to connect the interior of a computer with the biological world," said Buriak, associate professor of chemistry in Purdue's School of Science. "It is possible that this discovery will enable chips similar to those found in computers to detect biohazards such as bacteria, nerve gas or other chemical agents."
The research, which appears in today's (Wednesday, 12/11) issue of Nano Letters, sprang from the team's desire to attach metals to semiconductors in precise locations.
Computer chips, commonly made of silicon, contain circuits that are far smaller than those made from metal wires. But for an impulse from a keyboard or mouse to reach the microchip, the electronic signal must pass from a large wire onto the chip's surface. The delicate interface between the macro and micro world is often accomplished by a tiny connection made of gold, chosen frequently over alternatives such as copper or silver, because it does not corrode in air. Gold's advantages have made it the first choice for designers, though until now such advantages have come at a steep economic price.