Electret based vibration energy harvester for sensor network

Energy harvesting is an enabling technology for wireless sensor network and low-power-consumption wearable devices. Among various energy sources in the environment, structural vibration and human motion are most abundantly distributed. Since kinetic energy of the vibration is mainly concentrated in the low-frequency range, electrostatic induction generator using electrets attracts much attention. Here, recent progress of electret materials, charging methods, and device technologies are discussed for further developments of MEMS electret energy harvesters.