Design and testing of piezoelectric energy harvesting devices for generation of higher electric power for wireless sensor networks

This paper reports our design and testing results on the electric output performance of a vibration-based piezoelectric energy harvesting device (PEHD). The PEHD is a cantilever with a sandwich structure and seismic mass attached to the tip. The geometric parameters of the device are based on optimization design with a volume of around 1cm3 and at a targeted resonant frequency of 80-100 Hz. A maximum output power of 370μW at 15.5 volts into a 325kΩ resistive load is generated at the resonant frequency of 87Hz and under an acceleration of 0.23g. Quite remarkably, this power is a very encouraging power figure that gives the prospect of being able to power a wider range of applications than is currently possible in wireless sensor networ