A Piezoelectric Energy Harvester Based on Amplitude Amplification and Multidirectional Beam Frequency Modulation

Piezoelectric energy harvesters hold great potential in the field of energy conversion. In this article, a piezoelectric energy harvester based on amplitude amplification and multidirectional beam frequency modulation (PEH‐AMF) is proposed. Converting wave energy into electricity using a floating buoy is a conventional approach. Wave energy has the limitations of low frequency and insufficient amplitude, so the seesaw magnetic coupling method is adopted to achieve amplitude amplification. By tuning the nonlinear stiffness coefficient, the first‐ and second‐order natural frequencies can be shifted cooperatively, leading to improved electrical output. Based on the coupling dynamic model of Lagrange dynamic equation and piezoelectric constitutive equation, the different model responses of L‐beam is investigated by simulation modeling. Combined with the theoretical research, the influence of the main structural parameters of the device on the overall energy output conversion is explored. The feasibility of PEH‐AMF is confirmed by comparing the theoretical analysis, simulation and experimental data verification. Under optimal structural variables and experimental conditions, the PEH‐AMF achieves 8 mw power output under the excitation frequency of 2 Hz. This research provides a new idea and method for water surface energy capture.