A Piezoelectric Electromagnetic Composite Energy Harvester for Collecting Pedestrian Walking Energy

Abstract

A piezoelectric‐electromagnetic composite energy harvester (PECEH) has been designed, to mainly study the relationship between the length and angle of piezoelectric cantilever beams and their power generation performance, and the analysis of dynamic models in magnetic levitation systems and the impact of magnet size on power generation performance. In this device, piezoelectric energy harvester (PEH) and electromagnetic harvester (EMH) are used as powered and sensing, respectively. The PEH collects vibration to generate electricity and supplies energy to the EMH, which then transmits the wireless signal. EMH adopts a magnetic levitation device with higher sensitivity, while PEH uses a direct contact strike piezoelectric plate to increase power generation. The paddles are made of flexible materials, which increase the durability of the device. The prototype was tested at different excitation frequencies. Research has shown that at a frequency of 1.4 Hz, the optimal voltage and power are 126.28, 4.04 V, and 4.9 mW and 0.57 μW. 60 light emitting diode can be lit when pedestrians are walking. Therefore, PECEH can be used to collect the vibration energy of pedestrians while walking, providing power to sensors and microstructure.