A MEMS-based piezoelectric cantilever patterned with PZT thin film array for harvesting energy from low frequency vibrations

A piezoelectric energy harvesting cantilever integrated with Si proof mass has been presented to realize a low resonant frequency of 35.8 Hz. This paper describes the design, microfabrication and measurement of such device for harvesting energy from low frequency environmental vibrations. Instead of deposition of PZT bulk film, ten PZT thin film patterns (PZT patterns) are parallel arrayed and electrically isolated on the supporting beam of the cantilever. The performance of output voltage and power of PZT patterns in series and in parallel connections are studied based on the experimental and simulation results. It is shown that PZT patterns in series and in parallel connections produce the same level of power in the corresponding matched load resistance, but PZT patterns in parallel connection is preferred because of lower matched load resistance required.