Micro Fabrication Development of a Vibration-based Sputtered PZT Thin Film Micro Energy Harvester

We developed a micro fabrication process of vibration-based sputtered PZT micro energy harvester with a proof mass. A PZT film as a piezoelectric material is formed on a cantilever by using sputtering. An electric power is generated because of piezoelectric effect when the cantilever is bended and stressed. The device is fabricated on a Si substrate by MEMS techniques. The cantilever had 1200 mu m in length, 600 mu m in width, and 50 mu m in thickness on the Si substrate. Also, a PZT thin film free standing cantilever was successfully fabricated. A proof mass with 0.42 mg in weight was fabricated on both top of Si substrate cantilever and PZT thin film free standing cantilever. Dynamic and static frequency characteristics and output power generation were experimented by using a shaker and a network analyzer for characterizing the device. The resonant frequency of the Si cantilever was 8.81 kHz. We achieved 418 pW output power at the resonant frequency.