Charging smartphones by soundwaves

Finnish-based mobile technology giant Nokia and researchers at Queen Mary University of London are dreaming up a way to turn ambient noise into a power source for the cellphones of tomorrow. In a press release published Friday, the University describes how its team developed the experimental technology after observing performance boots in solar cells exposed to pulsing pop and rock music.

The key to converting sound into electricity, QMUL and Nokia found, is a particular application of zinc oxide — a water soluble, inorganic compound commonly used in plastics, ceramics and glass. Fibers coated in zinc oxide are particularly piezoelectric in nature, creating voltage when pressure is applied.

The team has manufactured a version of zinc oxide in the form of “nanorods” that can be applied to the surfaces of other materials. When exposed to the physical, vibrational energy that produces sound, the nanorods expand and contract, and that movement is converted into electricity. Researchers were able to create five volts of electricity, more than enough to charge a smartphone.