wow this sounds cool very exciting for the future worth keeping an eye on

"A battery for an electronic device is contained within a first frame that is coupled to a second frame by one or more piezoelectric elements. The second frame is coupled to a device chassis by one or more additional piezoelectric elements. In response to translation and/or rotation of the electronic device, portions of forces induced by the battery mass are transferred to the piezoelectric elements. Electrical energy output by these piezoelectric elements is received in a power controller and can be applied to the battery. Additional device components can also be contained within the first frame so as to increase the total mass that induces forces applied to the piezoelectric elements."

read on at US PATENT & TRADEMARK OFFICE