A lower-volume approach to liquid cooling, however, may be forthcoming from Cooligy, based in Mountain View, CA. The company is developing a microchannel-based cooling technology licensed from Stanford University. The technology is a smaller, on-chip version of the pump-and-pipe method of circulating liquids. In Cooligy's device, cooling liquid circulates through tiny channels carved into a silicon layer that sits on top of a computer chip.

Girish Upadhya, director of applications engineering at Cooligy, has cautious praise for ion-breeze cooling, which he calls "a unique approach which may have specific applications in spot cooling." But he suspects that the Purdue device could prove difficult to incorporate into computer chips. "The hard part is to come up with a specific product using such an approach," Upadhya says.

Intel, which collaborated with the Purdue researchers, is keeping its options open. The company has also worked on a similar ion-pump approach with researchers at the University of Washington, in Seattle. (See "Tiny Pump Cools Chips.")

But Garimella is confident that the Purdue device will yield practical applications. First, however, the researchers will have to make it smaller and more rugged. "The device is at the millimeter scale, and we are working on reducing it to the scale of tens of micrometers," Garimella says. A smaller device, he says, can achieve the same cooling effect with lower voltages. And that, he adds, "would make the technology commercially viable."