Autoparametric resonance in a piezoelectric MEMS vibration energy harvester

This paper reports for the first time the achievement of autoparametric resonance in a piezoelectric MEMS energy harvester without compromising transducer strain energy optimisation, in order to enhance the efficiency of vibration energy harvesting. The autoparametrically driven energy harvester in excess of a two-fold increase in power output than the same device driven into direct resonance at the same acceleration level, and about an order of magnitude higher in power density normalised to acceleration squared relative to the state-of-the-art.