Study on mirror-image rotating piezoelectric energy harvester

A mirror-image rotating piezoelectric energy harvester is proposed, and it can adapt to 2.8 m/s — 13.6 m/s wind speed. It is arranged by the mirror image of two piezoelectric elements, so it has multiple resonant frequencies. The multiple resonant frequencies make the bandwidth of the energy harvester be broadened. The force applied on the piezoelectric beam is aperiodic and an evaluable analytical model is established based on Fourier series and superposition principle. The influence of the system parameters on the piezoelectric beam is deduced by the Bernoulli beam formula of axial direction, and a prototype is made for experiment and application. The results show that when the distance between the two magnets is kept at 15 mm, the torsion angle of the blades is 15°, three blades are selected, and the height of each blade is 50 mm, the power generation effect is optimal, and the power can reach 12.5 mW. Under the optimal power, it only takes 100s to charge the capacitor of 220 μF to 15V, the prototype can directly power 98 light emitting diodes (LEDs) and make the calculator work. This technology can also be extended for harvesting water energy.