Mechanical modulation wave energy harvesting for self-powered marine environment monitoring

Small-scale wave energy harvesting can be used for self-powered marine environmental monitoring, with the advantages of sustainability, convenience, and environmental protection. The low-frequency and strong random fluctuations of ocean wave motion are not conducive to electromechanical conversion. In this paper, we propose a mechanically modulated wave energy harvester embedded with interference-free triboelectric nanogenerators. The mass pendulum oscillates under irregular low-frequency wave excitation, and then the oscillation is mechanically modulated into a unidirectional high-speed rotation of four permanent magnet disks. The elastic parts on both sides of the mass pendulum are functionalized into multi-layered folding triboelectric nanogenerators, which neither increase the volume of the wave energy harvesting system nor affect the operation of the electromagnetic generator. The prototype was manufactured and the experimental results show that the sum of the average power of the prototype is 4.8 W under excitation at a frequency of 3 Hz and a inclination angle of 40°. The 0.47 F capacitor can be charged to 5 V in 80 s by the prototype under the wave excitation generated by push plate, and then used for self-powered marine environmental monitoring (illumination, temperature and pH) and wireless information transmission.