Micro Seismic Electret Generator for Energy Harvesting

Abstract

Evaluation of a micro electret generator for energy harvesting applications is presented. MEMS-friendly perfluoropolymer, CYTOP is adopted as high-performance electret material. In power generation experiments using a prototype seismic generator, maximum power output of 0.278 mW has been obtained with 1.2 mm p-p in-plane oscillation at 20 Hz. Electrostatic force is calculated using one-dimensional electrostatic field model. It is found that the electrostatic force in the in-plane direction is almost constant irrespective to the direction of motion. When two separate generators with a 180 ˚ phase difference are inte-grated on a single chip, the horizontal force becomes smaller by two orders of magnitude, but exhibits different trends from velocity-damped or coulomb-damped resonant generators.