First on-chip cooling system?

From ZDnet:

Researchers at the University of Washington (UW) have developed a cooling device small enough to fit on a computer chip. This tiny ion pump uses an electrical charge 'rather than liquid or fans to create a cooling air jet right at the surface of the chip.' This research project looks so promising that even a company like Intel has been involved in it. But if there is a working prototype today, don't expect to work with a silent computer anytime soon. But read more…

Apparently, the idea is not new, but it's the first time that it has been physically demonstrated.

"With this pump, we are able to integrate the entire cooling system right onto a chip," said Alexander Mamishev, associate professor of electrical engineering [at UW] and principal investigator on the project. "That allows for cooling in applications and spaces where it just wasn't realistic to do before." The micro-pump also represents the first time that anyone has built a working device at this scale that uses this method, Mamishev added.

Here are two infrared images showing how the new UW micro-pump cools a heated surface. On the top image, the air pump is off, while it is on in the bottom image. (Credit: University of Washington)

But how this pump works? Here are some details given by UW — but remember that Intel is working on it, so don't expect thorough explanations.

The device utilizes an electrical field to accelerate air to speeds previously possible only with the use of traditional blowers. Trial runs showed that the prototype device significantly cooled an actively heated surface on just 0.6 watts of power.

The prototype cooling chip contains two basic components: an emitter and a collector. The emitter has a tip radius of about 1 micron – so small that up to 300 tips could fit across a human hair. The tip creates air ions, electrically charged particles that are propelled in an electric field to the collector surface. As the ions travel from tip to collector, they create an air jet that blows across the chip, taking heat with it. The volume of the airflow can be controlled by varying the voltage between the emitter and collector.

Some of this research work has been shown at the 9th AIAA/ASME Joint Thermophysics and Heat Transfer Conference, which was held in June 2006 in San Francisco. The paper presented there was named "Coupled-physics modeling of electrostatic fluid accelerators for forced convection cooling," and is available in the Conference Proceedings for $850 ($750 for AIAA members). Oooch!

Anyway, you can keep your habits of opening your laptops and desktops to clean the dust around the fans for several years. According to the researchers, several challenges remain before their device can be used by semiconductor companies.

Sources: University of Washington news release, via EurekAlert!, August 23, 2006; and various web sites.