A smoke ring can be a pleasing thing to look at. At the Georgia Institute of Technology, Ari Glezer and Mark G. Allen are building devices that could boost the power of computer chips by blowing similar vortices of fresh air. Keeping chips cool is a crucial requirement in electronic design.
Fans are the traditional solution, but they are cumbersome and inefficient.
Glezer and Allen adapted the principle behind a smoke-ring generator to make a device that efficiently cools circuits and can be made small enough to chill individual chips. Vibrating the flexible wall at a suitable frequency causes cooling jets of vortices to emerge from the holes. Allen has made devices with holes as small as 100 microns in diameter. That makes it possible to think of micromachining such devices into a chip, Glezer notes. They need no external plumbing, and because the microjets are highly directional, they can be pointed where needed.