Harvesting weak vibration energy by integrating piezoelectric inverted beam and pendulum

Scavenging energy from weak ambient vibration is significant for powering wireless sensors and transducers. To harvest more energy from weak vibration, we proposed a rigid-elastic energy harvester composed of an inverted piezoelectric beam and a pendulum (IPBP). The finite element model was established, and corresponding simulations were performed. The results prove that the IPBP could exhibit different nonlinear characteristics at different resonance frequencies. Then, the experimental study was conducted. The experimental results are in good agreement with the simulation predictions. Furthermore, it is found that there exists mode coupling in the IPBP, by which the excitation at high frequency could excite the response at low frequency. Mode coupling is beneficial for the IPBP to trigger snap-through motion under weak excitation. The experiment proves that under stochastic excitation, the IPBP could execute snap-through motion through mode coupling and thus generate a large electrical output. This study may provide a new method to improve the harvesting performance of weak excitation.