IN-plane gap-closing mems vibration electret energy harvester on thick box layer

In this report, an improved in-plane electret energy harvester with gap-closing comb drives has been developed with a single-mask SOI process. By using 150 μm-thick device layer for increasing the seismic mass and 15 μm-thick buried oxide layer for reducing the parasitic capacitance, up to 5.3 μW output power has been obtained at 503 Hz, which is equivalent of five times higher power output than our previous prototype. In addition, the power output reaches as high as 45% of the Velocity-Damped Resonance Generator (VDRG) limit.