Looks like all that heat generated by your laptop may finally be useful for something other than frying eggs -- a group of grad students led by professor Orest Symko at the University of Utah has unveiled an array of "thermoacoustic" engines that turn heat into sound, which can be directed at a piezoelectric mechanism to produce electricity. The US Army-funded research seems promising but is obviously still in its infancy -- one of the designs the researchers demonstrated is half the size of a penny but pumps out 120dB of noise (about the same as a siren), while another bumped out over 135dB, (which is roughly equivalent to a jackhammer). The team expects that future, smaller designs will work at ultrasonic frequencies outside the range of human hearing. Although we're not expecting hybrid-siren-powered laptops to hit anytime soon, you Utes out there may want to invest in some earplugs -- Professor Symko says they'll be testing these designs at the University's water-heating facility in the next year.

It would be funny to hide these on cars.