Piezoelectric Promise: Charge a Touch-Screen by Poking It With Your Finger

Imagine a day in the future when you can charge your cell phone using your sneakers, or charge a touch-screen device merely by rolling up the flexible screen. New devices that take advantage of the piezoelectric effect--the tendency of some materials to generate an electrical potential when they're mechanically stressed--are taking us one step closer to that reality. Ville Kaajakari of the Louisiana Tech University harnessed this effect by developing a tiny generator that can be embedded in a shoe sole.