A piezoelectric-electromagnetic hybrid energy harvester for low-frequency wave motion and self-sensing wave environment monitoring

Techniques for harvesting energy and environmental monitoring are crucial for the development and application of wave energy. Here, we propose a piezoelectric-electromagnetic hybrid energy harvester (PEHEH) for low-frequency wave motion and self-sensing wave environment monitoring. The PEHEH consists of an electromagnetic energy harvester (EMH) and two distinct types of piezoelectric energy harvesters (PEH-1 and PEH-2). The combination of piezoelectric power generation and electromagnetic power generation can effectively harvest low-frequency wave energy. Using the L-shaped piezoelectric cantilever can make it produce large deformation under low-frequency excitation to obtain better power output. The movement of the spherical magnet in the channel tube changes the magnetic flux in the coil to generate electricity. The PEHEH is designed to float on the surface of the water to harvest wave energy in multiple directions. According to the experimental findings, the PEHEH can obtain a power output of 32.58 mW with the optimal combination of parameters. The PEHEH can supply power to the LEDs and enable them to emit light properly. Meanwhile, using the PEH-1 and PEH-2 as the power supply part and the EMH as the self-sensing part, the PEHEH can realize the monitoring of wave amplitude in the actual wave environment. The above results verified that PEHEH has the functions of self-powering and self-sensing. This research provides a novel technical solution for the development and utilization of wave energy.