Swing-Translational Hybrid Triboelectric–Electromagnetic Water Wave Energy Harvester

Wave energy is a promising source of green renewable energy. However, its inherently low frequency results in poor energy harvesting efficiency, and its intermittent and unstable characteristics pose considerable challenges to effective energy collection. To overcome these limitations, this study proposes a hybrid triboelectric–electromagnetic generator (HTEG) that converts the swing motion of devices into the translational sliding of sliders through an inverted-triangle structural design. Sliders are mounted on the three surfaces of the inverted triangle and interconnected by a pulley system, enabling the integration of five triboelectric nanogenerator (TENG) modules and three electromagnetic generator (EMG) modules within a confined space, thereby significantly improving spatial utilization. Magnets are embedded inside the primary slider located at the top surface of the inverted triangle, serving both as counterweights to increase sliders velocity and as components of the EMG module. The lateral surfaces adopt a double-layer structure, with magnets placed at the upper layer, while the secondary sliders incorporate embedded coils and fluff-covered upper surfaces. By optimizing fluff length and magnet arrangement, the volumetric power density of the device is substantially enhanced. Under a simulated wave environment with a frequency of 0.5 Hz, the HTEG achieves a maximum volumetric power density of 24.1 W·m–3, sufficient for continuously powering small electronic devices.