A groove engineered ultralow frequency piezomems energy harvester with ultrahigh output voltage

Abstract

In this paper, for the first time, a new design for a MEMS cantilever-based energy harvester (EH) has been proposed which takes advantage of two engineered piezoelectric layers. The output voltage of the EH has been increased by the aid of making grooves in the piezoelectric layers. By application of the grooves in the piezoelectric layers, the sensitivity of the cantilever as the vibration sensor or the EH has been improved. Results have shown that these grooves can increase the output voltage and decrease the resonance frequency which are desired changes in designing EHs. The single and double groove bimorph cantilevers have been compared and discussed. The position, length and depth of the grooves have been used as optimization parameters and consequently an optimal design has been proposed at the end of the paper. In the optimal design the top and the bottom piezoelectric layers have not covered the entire beam and have different lengths to produce maximum voltage. By means of groove engineering, we could rise the voltage from 5.395 V to 28.35 V which is considered a great improvement compared to other structures reported previously.