Design and experimental study of magnetically excited variable cross section bending beam piezoelectric energy harvester

This paper proposes a novel magnetically excited variable cross section bending beam piezoelectric energy harvester (ME-VCB-PEH) to overcome the limitations of current piezoelectric energy harvesters, such as narrow bandwidth and single-directional collection. Firstly, a nonlinear distributed parameter model of the ME-VCB-PEH is established based on Hamilton's principle, and the optimal distance between magnets is derived, providing a theoretical basis for subsequent research. Secondly, through simulation and experimentation, the optimal structural parameters of the ME-VCB-PEH are determined. Finally, an energy harvesting test platform is constructed to test its output performance and application effectiveness. The results show that compared to rectangular and trapezoidal beams, the VCB structure exhibits lower frequency, wider bandwidth, and higher output voltage. The designed ME-VCB-PEH effectively harvests vibration energy in three axial directions below an external frequency of 80 Hz, effectively meeting the auxiliary power supply needs of temperature sensors and wireless transmission modules for the roadheader under normal operating conditions. This technology provides an important technical reference for self-powered wireless sensing technology and plays a significant role in IoT and sensing applications.