A Bimorph Multi-layer Piezoelectric Vibration Energy Harvester

This paper reports a bimorph piezoelectric vibration energy harvester incorporating multiple PZT layers. The advantage of a multi-layer generator is that it produces a higher power than a single-layer generator having the same total thickness. In addition, a lower voltage is required to polarize a multi-layer generator reducing the risk of breakdown during polarization. Moreover, the optimum resistive load of a multi-layer generator is much lower than that of a single-layer generator, which makes it easier to couple to the electrical domain. In this work, it was found, experimentally, that a double-layer generator produces 41.5% and 19.4% more power than a singlelayer generator with the same total thickness of PZT and resonant frequency. This was verified theoretically. The generators have been fabricated by screen printing which is attractive for low cost mass production.