Abstract
This paper presents design and experimental characterization of a vibration electret energy harvester with vertical electrets. The electromechanical optimal design of the in-plane energy harvester with comb electrodes was made to maximize the mass and the capacitance variation in a given area and thus to maximize the output power. A MEMS electret energy harvester is microfabricated using the SOI technologies without any assembling processes. Soft X-ray charging is employed to implant electrons into the vertical electrets with narrow gap opening. Uniform surface potential is obtained up. to the depth 10 times of the gap opening. An output power of 0.4 μW has been obtained at 300 Hz and 2g, which corresponds to the effectiveness as high as 14.8 %.
