Polymer Energy Harvester
Converting the kinetic energy of human movement into electrical energy has become an attractive approach to powering wireless electronic devices in recent years. The combination of energy harvesting and portable body-worn electronics forms a self-sufficient system that finds application, for example, in fitness gadgets for tracking temperature, speed and position data. Based on novel electroactive polymers, an innovative energy harvesting system has been developed that is small enough to be integrated into a shoe sole. The element, which converts mechanical energy into electrical energy, is based on thin polymer films with high relative permittivity. Compared to traditional piezoelectric concepts, this element operates non-resonantly and can be optimized for energy harvesting from mechanical energy sources even at low frequencies.
A first demonstrator of a polymer energy harvester integrated into a shoe is available. It is capable of generating a few µWs of energy when subjected to mechanical deformation by pressure and frequency range typical of human gait. In this case, the transducer circuit is tuned to supply an RF transmitter module. The harvester system (element and circuit) can be adapted for other applications such as powering a variety of application-specific electronics.