Imagine that one day you could charge your mobile phone or other low-consumption devices just by placing them in noisy areas or by yelling at them. South-Korean scientists from the Sungkyunkwan University in Seoul, are now studying a type of zinc oxide-based device that could do just that.
Just as speakers turn electricity into sound, the reverse is also possible, thanks to an effect called “piezoelectricity.” Sound of about 100 decibels could as well get transformed into electrical impulses that could be fed into a battery.
Strands of zinc oxide sandwitched between two electrodes are compressed and released by a sound-absorbing membrane on top. In fact, this principle is already being used in piezoelectric microphones like the one you’re carrying in your phone, but now researchers are aiming for something much more efficient.
They even envision millions of these zinc oxide strips mounted nearby motorways, to gather the noise produced by rush-hour traffic and transform it into usable electricity. This could have another beneficial side effect, as it could absorb the energy otherwise dissipated into homes near to the road.