Engineering a motion-enhanced tri-stable hybrid energy converter for capturing low-frequency wave energy

This paper presents a new design concept of incorporating a multi-stable nonlinear system with speed amplification designed for a hybrid-based low-frequency wave energy converter (WEC). The design features a tri-stable nonlinear, array-type electromagnetic generator paired with a conveyor belt-style, grating-structured, freestanding triboelectric generator. A roller-belt mechanism can increase the relative speed between the oscillator and translators of the hybrid WEC by a factor of two. The combination of the array magnet and speed amplification also enables the generation of voltage frequency in the electromagnetic generator. The mechanical and electrical characteristics of the fully integrated WEC are assessed through both experimental measurements and numerical calculations. Experimental results show that the designed WEC operates effectively within a frequency range of 0.1–2 Hz, achieving a peak power output of ∼311 mW at 2 Hz under an acceleration of 0.25 g. Ultimately, a capacitor charging experiment carried out in a wave environment shows that the power supply is sufficient for powering small electronic devices.