A low-frequency piezoelectric wave energy harvester based on segmental beam and double magnetic excitation

Wave energy is a source of clean energy with huge reserves, but its application is limited owing to the low frequency of the waves. This paper proposes a low-frequency piezoelectric wave energy harvester (L-PWEH) based on segmental beam and double magnetic excitation. The L-PWEH uses a combination of mechanical and magnetic frequency tuning to achieve an improved output performance in low-frequency wave environments. The natural frequency of the segmental beam is effectively reduced by using the mechanical tuning method of the segmental beam structure. With the introduction of the tuning magnet, a double magnetic excitation of the segmental beam is formed to make it more susceptible to deformation. Multiple magnets on the rotor for excitation can obtain a better broadband effect. Through theoretical and simulation analysis, the primary variables influencing the output performance of the L-PWEH are discovered. Under ideal testing conditions, the L-PWEH can produce a peak power of 31.21 mW when the external resistance is 30 kΩ. The thermohygrometer can function effectively and be illuminated by 142 light-emitting diodes (LEDs) thanks to the L-PWEH. These findings confirm that the L-PWEH can supply low-power electronic devices with electricity.