OK OK don’t get too excited yet because it’s still theoretical.
But Cagin (a professor in the Artie McFerrin Department of Chemical Engineering at Texas A&M University) and his partners from the University of Houston have found that a certain type of piezoelectric material can covert energy at a 100 percent increase when manufactured at a very small size.
Cagin says: Even the disturbances in the form of sound waves such as pressure waves in gases, liquids and solids may be harvested for powering nano- and micro devices of the future if these materials are processed and manufactured appropriately for this purpose.
Which means that you could charge your phone while you are talking on it. Imagine a self-powering cell phone that never needs to be charged because it converts sound waves produced by the user into the energy it needs to keep running.