Wednesday, November 01, 2006

Self-Cooling Microchips

Silicon ion pump creates a breeze.

By Kate Greene

An "ion pump" (dark purple square) sits atop a microchip. Cooler regions show up in purple when the pump is turned on. (Credit: Larsen, University of Washington)

As computer chips are crammed with more and more transistors, they run hotter, and traditional cooling mechanisms--heat sinks and fans--are having trouble keeping up. But future chips might cool themselves with a special ­gadget that uses ionized air and an electric field to create a tiny breeze. In a so-called ion pump, a high voltage across two ­electrodes strips electrons from molecules of ­oxygen and nitrogen in the air, creating positively charged ions. These ions flow to the negatively charged electrode, dragging along surrounding air molecules and cooling the chip. Researchers from Intel, the University of Washington Seattle, and ­Kronos Advanced Technologies of Redmond, WA, say a prototype can cool a two-­square-­millimeter spot on a ­surface by 25 ºC. Since the ion pump is made from silicon, it can be constructed as part of the chip-making process. Project leader Alex Mamishev, an electrical engineer at the University of Washington, says he expects the technology to be incorporated into commercial chips within two years.