Performance comparison of PZT and PMN–PT piezoceramics for vibration energy harvesting using standard or nonlinear approach

This paper reports the performance comparison of two common piezoelectric compositions for energy harvesting purposes, using either a standard or a nonlinear technique. Unlike single crystals, piezoelectric ceramics are quite easy to obtain, and thus their application to realistic applications is feasible. This study focuses on two compositions: PZT + 1 mol% Mn and PMN–25PT, obtained from sintering piezoelectric powders, and highlights the advantages and drawbacks for each of them. Then the obtained samples are evaluated for energy harvesting purposes, either by connecting them directly to the harvesting stage or by adding a nonlinear interface that consists of inverting the piezovoltage synchronously with the structure motion, leading to an artificial increase of the conversion abilities. The piezoceramics show a significant difference in power generation ability when using the classical energy harvesting technique. However, it is demonstrated that the use of the nonlinear treatment on the output voltage of the transducers leads to a great reduction in this discrepancy in spite of the difference in ceramic compositions.