Micromachined piezoelectric energy harvester with low vibration

In this paper, a piezoelectric MEMS energy harvester was investigated and evaluated to scavenge power from ambient vibration source. It was optimally designed to generate the electrical power from low level ambient vibration via the piezoelectric effect. In order to generate the electricity at low vibration, the proposed energy harvester was fabricated by patterning platinum electrode into inter-digital geometry on top of the sol-gel-spin coated Pb(Zr,Ti)O₃ thin film for d₃₃ piezoelectric mode operation on the silicon cantilever with proof mass by using bulk micromaching technique. The fabricated energy harvester has a 1.1 uW of output power to 2.2 MOmega of load resistance with 4.4 V_peak-to-peak from a vibration of 0.39 g acceleration at its resonant frequency of 528 Hz. The corresponding power density was 2.8 mWmiddotcm^-3middotg^-1.