AN ELECTRET ENERGY HARVESTER FOR KINETIC ENERGY AT ULTRA-LOW FREQUENCY

This paper proposes an electret energy harvester based on an inertial rotating structure to collect ultra-low frequency kinetic energy. The harvester can convert the low-frequency linear motion into the high-speed rotational motion to improve the power output. The main affecting factors on output performance have also been investigated, such as excitation frequency, pressing velocity, and number of fan-shaped blades. At 1 Hz excitation frequency and 250 mm/s pressing velocity, the harvester with 10 blades can generate an average output power of 146.8 mu W and a normalized power density of 8.3 mu W/cm2. Finally, a self-powered wireless sensing system based on the energy harvester has been successfully demonstrated.