Development of a low frequency electrostatic comb-drive energy harvester compatible to SoC design by CMOS process

A 3000 mu m x 3000 mu m x 500 mu m in-plane, gap overlap, electrostatic comb-drive operating in charge-constrained cycle is developed to harvest ambient vibration. This is the smallest vibration harvester resonating at 105 Hz, implementable by standard CMOS process and compatible to System-on-Chip (SoC) design. The 2000 mu m x 2200 mu m x 450 mu m (4.9 mg) vibrating mass is made of the CMOS handle layer so as to achieve low frequency operation. Design verifications show that, with the excitation input of 10 mu m amplitude at 105 Hz, the harvester can generate an average output power of 0.0924 mu W, or equivalent output density 0.021 mu W/mm(3). The design is the most area-efficient CMOS vibration energy harvester reported to date. (C) 2010 Elsevier By. All rights reserved.