clock menu more-arrow no yes

Filed under:

Circuit Breaker

Bouncing water droplets could be used to keep computer processors cool

New, 5 comments

The droplets bounce off super-hydrophobic surfaces, dissipating heat as they do

Video showing water droplets bouncing off a super-hydrophobic surface.
Image: Chuan-Hua Chen, Duke University

Scientists from Duke University and Intel have come up with a new mechanism for keeping high-performance electronics cool: fill their insides with bouncing water droplets. It sounds like a late April Fools’ joke, but the researchers say such a system could keep high-performance electronics running at full speed by organically targeting hot-spots.

The proposed technology, described in the journal Applied Physics Letters, was inspired by the super-hydrophobic wings of cicadas, which naturally repel water. When two small water droplets collide on a cicada’s wing, they join together to form a bigger droplet. This change releases a small amount of energy that’s enough to lift the water off the wing’s surface, taking dust and dirt with it. This means the wings are self-cleaning, but the engineers figured the same principle could be also used to remove heat.

Of course, no one wants to spill water on sensitive circuits, so the researchers created a sealed “vapor chamber” that can be installed within electronic systems. On one side of the chamber is a super-hydrophobic floor, and on the other, a sponge-like ceiling. As the chamber is heated by the surrounding electronics, the vapor condenses into tiny water droplets. These fall onto the super-hydrophobic floor, join together into bigger droplets, then ping off the surface, taking heat with them. The water is then soaked back up by the sponge-like ceiling and the whole process stars over.

An illustration of the vapor chamber, with its hydrophobic floor and sponge-like ceiling.
Image by Chuan-Hua Chen / Duke University

The clever thing about this system is that it automatically targets hot-spots, as those areas are where the water vapor will condense first. And, unlike existing cooling mechanisms, this system also works on two planes at the same time — vertical and horizontal — meaning the cooling happens more efficiently.

“Flat-plate heat pipes are remarkable in their horizontal spreading, but lack a vertical mechanism to dissipate heat,” said Chuan-Hua Chen, associate professor at Duke and co-author of the study, in a press statement. “Our jumping-droplet technology addresses this technological void with a vertical heat spreading mechanism, opening a pathway to beat the best existing heat spreaders in all directions.”

Chen says these vapor chambers are “comparable” to commercial cooling systems, but that a lot more work is needed to be to create systems that will continue to operate over time. “But now, for the first time, I see a pathway to beating the industry models.”