Highly Sensitive Hybrid Triboelectric Nanogenerator with Ferris-Wheel-Like Structure for Ocean Wave Energy Harvesting

Ocean wave energy represents a widely distributed and abundant clean, renewable energy source. However, its efficient harnessing remains a challenge. In this study, a triboelectric-electromagnetic hybrid generator of a Ferris-wheel-like structure (FWS-TEHG) with magnetic repulsion assistance is proposed to effectively enhance the collection of low-frequency and low-amplitude water wave energy. The Ferris-wheel shell and the internal rotator are designed with a phase difference to heighten the swing amplitude, while the introduction of magnetic repulsion augments the motion frequency. The device has demonstrated excellent performance in low-frequency conditions, from laboratory to ocean wave tests. Operating at a frequency of 0.5 Hz and a swing angle of 12° on a six-freedom platform, it lights up 64 LEDs with a power rating of 2 W. Triggered by simulated water waves with a frequency of 1 Hz, the FWS-TEHG charges a 19 mF capacitor at an average charging rate of ≈0.58 W h⁻¹, powering a water-level alarm. In oceanic conditions, the FWS-TEHG effectively harvests energy from water waves by exhibiting an output frequency approximately four to five times higher than that of the primary frequency of ocean waves, thus enabling it to power electrical devices such as temperature–humidity meters efficiently. This study provides a valuable reference for advancing the practical application of nanogenerators in natural ocean environments.