ZnO-nanowires based power generation from low frequency vibration

This paper presents the fabrication and test of a low-frequency ZnO-Nanowires (NWs) based energy harvesting device. The vertically aligned ZnO NWs are grown by hydrothermal method of low temperature and low cost. A flexible PDMS cantilever of low resonance is employed to be the mechanical vibration carrier of a top electrode. The periodic impact between the top electrode and a bottom ZnO NWs substrate is introduced by the PDMS cantilever. The impact-induced bending of the NWs produces a maximum output rms voltage of 4.8 mV at the resonant frequency of 39.2 Hz and the acceleration of 2.5g. The design has demonstrated wide bandwidth characteristics. The full width at half maximum (FWHM) increases from 16.8 Hz to 20.5 Hz as the acceleration increases from 1g to 2.5g.