The next generation of chips are gonna need some major coolin’, perhaps as much as 1000 Watts of cold per square centimetre. We’re talkin’ high-speed microprocessors, optoelectronics, micro- and millimeter-wave power electronics and power conditioning transistors for electronic motor control in hybrid vehicles power converters etc. These are machines that will generate significant heat.
Ordinary coolin fans ain’t gonna work for those kindsa fluxes so alotta engineers have been thinkin’ about phase change systems in which a liquid absorbs heat, boils into a gas and carries the energy away.
The trouble is that a vapor layer tends to form over the surface of a chip and this acts as an insulator preventing further heat transfer.
So Ari Glezer and pals at the Georgia Institue of Technology in Atlanta have come up with a way of dislodging the vapor by bombarding it with sound. It’s just a pump for pushing the liquid round with a piezovibrator to create an acoustic field.
They reckon it works well and at relatively low power. In their set up, they achieve a colling rate of 165W per square cm. But with acoustic zapping they can raise this to 338 W per square cm. That’s an improvement of 150%.
Ref: arxiv.org/abs/0801.0785: Acoustically Enhanced Boiling Heat Transfer
165 to 338 is an 105% increase.