A Highly Robust Out-of-Plane Electrostatic Vibration Energy Harvester with Wide Bandwidth

This article presents a highly robust and wide-bandwidth out-of-plane electrostatic vibration energy harvester using end-stop impacts. Metal plates and insulated frame were used to assemble the energy harvesters for application environment with extremely high vibration acceleration. An insulated stopper-plate was used to generate the impact effect to broaden the bandwidth along with the improvement of robustness. The electrostatic energy harvester was measured without any structure broken in a vibration test with maximum acceleration up to 6.0 g. Mathematical model and experimental results indicate that the bandwidth can increases to 49.16 Hz along with a stable output voltage 0.6 V when an external vibration of 1.5 g and 95 V bias voltage were used. It is suggested that the piecewise-linear stiffness caused by the stopper-impact effect and the spring softening nonlinearity induced by the strong electrostatic force play important role in broadening the bandwidth.