Multi-cantilever piezoelectric MEMS generator in energy harvesting

In this paper, we present the development of a multi-cantilever piezoelectric MEMS generator, which has the ability to scavenge mechanical energy of ambient vibrations and transforms it into useful electrical power. The generator comprises four cantilever type devices, two d₃₁ mode devices and two d₃₃ mode devices, which were made by a silicon process in a single die. We developed a PZT deposition machine which uses an aerosol deposition method to fabricate the PZT thin film efficiently. The four cantilever devices can be connected in series or in parallel so as to possess different output characteristics. The measurement results show that our prototype device possesses resonance frequencies between 237 Hz and 244.5 Hz.