Development of Piezoelectric MEMS Vibration Energy Harvester Using (100) Oriented BiFeO3 Ferroelectric Film

Abstract

Piezoelectric vibration energy harvesters (VEHs) with unimorph structure have been developed using Si micro-electrical mechanical systems (MEMS) technology. Since we revealed that (100) epitaxial BiFeO3 (BFO) piezoelectric films have high figure-of-merit on energy conversion, (100)-oriented BFO films have been prepared on (100)-oriented LaNiO3 bottom electrodes by the sol-gel method. We fabricated the piezoelectric VEHs using BFO films with resonance frequencies of ~100 Hz. The maximum output power density of these VEHs was determined to be 10.5 μWmm−3G−2 (G=9.8 ms−2) at a load resistance of 1 MΩ, which exceeds or is comparable to those of the best-performing VEHs using other piezoelectric films.