Design and performance of hybrid piezoelectric-electromagnetic energy harvester with trapezoidal beam and magnet sleeve

Abstract

At present, piezoelectric energy harvesters are disadvantaged by their low efficiency and high operating frequencies. To address these shortcomings, we propose herein a hybrid piezoelectric-electromagnetic energy harvester (HPEH) for the low-frequency vibration environment, which is composed of a piezoelectric part featured with a double-clamped trapezoidal beam and an electromagnetic part featured with a magnet sleeve and plane coils. The modeling and experiment of the HPEH were carried out to optimize the structure and performance. We find experimentally that the proposed device not only increases the piezoelectric output but also highly improves the electromagnetic output. At the excitation acceleration 2 m/s2, the average output power of the piezoelectric part and the electromagnetic part is increased by 30.5% and 20 times, respectively. The total output power of the HPEH is increased by 52.4%, reaching 0.637 mW. The results show that the proposed HPEH can efficiently use vibration energy to improve its output performance, which has the potential to power wireless intelligent sensor network and wearable electronic devices.