Researchers Build Prototype Ion Pump to Cool Chips

Published: September 5, 2006

by Timothy Prickett Morgan

Chips are too hot these days, and fans are not a terribly efficient means of cooling them. While having air-cooled computers is much-preferred compared to the water-cooled past of mainframes (or the present of extreme PC users who over-clock their boxes and who have revived a variant of water cooling for the PC), air is nonetheless a relatively poor conductor of heat and you have to use a lot of energy and make a lot of noise to move cold air to computers and hot air away from them.

Researchers at the University of Washington, Intel, and Kronos Advanced Technologies have collaborated to create a nanoscopic ion pump that can be integrated on the surfaces of chips to electrically and directly create air currents that can take heat away from chips as they run.

Alexander Mamishev, an associate professor of electrical engineering at the university, is the principal investigator behind the miniaturized ion pump, says that the idea has been around for years, but no one built a working prototype.

The pump has two basic parts: an emitter, which is a 1 micron wire that ionizes air, and a collector, a device that, as its name suggests, is a wire a few microns away that collects the ionized air. The electric field between these two devices causes the air to move, and at speeds comparable to that of air that is moving because a fan is whirring. If you want to move a lot of air, you create a chip package with a lot of emitters and collectors on it, much as you pack a lot of transistors on a chip to make a memory cell, and you program the wires to move air in stages across the chip, or you aim air flow at hot spots on the chip as different chip features are being used. (This is one of the tough problems that researchers are still trying to work out.). If you want to move a lot more air, you can also jack up the voltage. The important thing is that an ion pump that has an area of a few tens of square microns can cool an area of several square millimeters. The prototype cooled a chip that was running hot on just 0.6 watts.