Wallpaper Speakers - Flexible Piezoelectric

Piezoelectric materials (crystals like quartz) can be used inside microphones and speakers in order to convert incoming electricity to sound, but they are brittle and bulky. Material scientist, Michael Yu, at Johns Hopkins University in Baltimore has found and patented a way to make piezoelectric devices such that they are now so lightweight and flexible, they can be put into small devices - even wallpaper or folding speakers.

The invention is a rubbery, plastic-based material which is in turn based on a 2004 discovery of a polypropylene foam with piezoelectric properties. This is the first time a piezoelectric material can be flexible without losing its key characteristics.