Abstract
Wave energy is a high-density clean energy source, but has not been widely applied due to ultra-low frequency and directional variability issues. Therefore, a bistable wave energy harvester with orientation-adaptive characteristics is proposed in this paper, which utilizing a driven roller and non-linear driving magnetic force, irregular, ultra-low frequency, arbitrary direction wave motion is converted into regular rotational motion of the driving magnet and high frequency vibration of the generator beam. Furthermore, a theoretical analytical model of the harvester was established, including a kinetic analysis of the driving magnet, an analysis of the nonlinear driving magnetic force, an analysis of the control equations of the system and the bistable properties of the generator beam. Finally, the harvester model was fabricated for studying the effect of key parameters on output performance, including magnetic distance, driving magnet diameter, wave direction, and external resistance. The maximum voltage RMS value is 1580.69 mV, and the maximum output power is 1.56 μW. The proposed harvester is capable of efficiently harvesting energy in a multi-directional ultra-low frequency wave environment.