This new approach to energy harvesting uses electrets, materials with special electrical properties that already are used in microphones and in tiny MEMS devices. This latest application, developed by researchers at Disney Research, Pittsburgh and at Carnegie Mellon University, could make possible new types of interactive applications involving books, posters and other printed materials that require no batteries or external power.
The design of a Paper Generator is simple: one approach is to sandwich a thin, flexible sheet of polytetrafluoroethylene, or PTFE – best known by the brand name Teflon –between two conductive layers, such as sheets of metallized polyester, that serve as electrodes. Electrical charge accumulates on the PTFE sheet when paper is rubbed against it. Then, if the electrodes are made to move relative to each other against the PTFE, a tiny, alternating electrical current is generated. This electrical current can be used to power a broad variety of devices such as LED arrays, e-ink displays, sound buzzers and infrared communication devices.
Read more at: Phys.org