Development of a double-torque driven piezoelectric-electromagnetic energy harvester with see-saw structure

Rotating energy harvesters are used to convert mechanical energy into electrical to power sensor devices. However, as the number and variety of sensors increases, there is a growing need for energy harvesters to achieve higher output power. This paper proposes a novel piezoelectric-electromagnetic energy harvester for harvesting rotational energy from the environment. It is particularly well-suited to outdoor wind turbines and vehicle wheel energy harvesters. The main structure uses a see-saw structure passing through closed coils, incorporating two piezoelectric cantilever beams to achieve a compact design and high output. The see-saw structure is torqued with an attractive force on the one side and a repulsive force on the other. By synergizing the magnetic attraction force on one side with the magnetic repulsion force on the other side, a double torque effect is achieved, which enhances the speed at which the magnet cuts through the coil. Under load, compared with the single-torque harvester, the double-torque driven energy harvester exhibits a 19% and 25% increase in maximum output power and voltage, with maximum output power at 5.76 mW. The prototype can successfully illuminate 60 LEDs; it offers a new and effective way to collect energy and improve efficiency in the future.