‘New ways of turning heat into sound waves – and then into electricity – may be the next step toward a practical new source of alternative energy.
Scientists have known for decades that they can turn heat into sound using simple devices called acoustic heat engines. But this week a team of University of Utah researchers plan to show they’ve succeeded in miniaturising and optimising the devices, which then turn the sound into usable electricity.
If true, the advance could open the door to super-efficient power plants, cars, and computers, as well as a new generation of solar cells.
Acoustic heat engines usually use a copper plate to conduct heat to a high-surface-area material like glass wool, which then heats the surrounding air. The movement of the hot air generates a single frequency sound wave, rather like a flute. And this in turns vibrates a piezoelectric electrode, producing voltage.’