High performance piezoelectric MEMS energy harvester based on D33 mode of PZT thin film on buffer-layer with PBTIO3 inter-layer

In this paper, a MEMS energy harvester was investigated to scavenge power from ambient vibration source. It was designed to convert low level vibration to electrical power via the piezoelectric effect. The proposed energy harvester was fabricated by patterning Pt electrodes into inter-digital geometry on top of the sol-gel-spin coated Pb(Zr, Ti)O₃ thin film for d33 mode on silicon cantilever with proof mass. In order to obtain well grown PZT thin film, PbTiO₃ seed-layer was newly applied as an inter-layer between PZT and ZrO₂ layer. The fabricated energy harvester generated 1.1 uW of electrical power to 2.2 MOmega of load with 4.4 V_peak-to-peak from a vibration of 0.39 g acceleration at it resonant frequency of 528 Hz. The corresponding power density was 2.8 mWmiddotcm^-3middotg^-1.