Scientists from Finnish cellphone company Nokia and researchers from Queen Mary University of London have teamed up to develop technology that uses sound to charge mobile phones. The team used what is called a piezoelectric effect, in which zinc oxide nanowires convert sound vibrations into electricity.
The scientists sprayed a liquid zinc oxide coating onto a plastic sheet, before placing it in a mixture of chemicals to help the material grow into nanorods.
The researchers currently have one prototype device capable of harnessing sound for battery power. The device is about the size of a Nokia Lumina 925 and can generate up to five volts of power using everyday sounds such as traffic, music and voices. Five volts is generally enough to charge a mobile phone.