Hybrid Triboelectric-Electromagnetic Nanogenerator with a Double-Sided Fluff and Double Halbach Array for Wave Energy Harvesting

Harvesting wave energy is challenging due to the waves' direction, randomization, and ultra-low vibration frequency limitations. Here, a double-sided fluff and double Halbach array structured hybrid triboelectric-electromagnetic nanogenerator (FH-HG) for harvesting ultra-low frequency wave energy is reported. The double-sided fluff fabricates three triboelectric nanogenerators (TENGs), which significantly enhance space utilization and volume power density. Meanwhile, the double Halbach array electromagnetic generator (H-EMG) provides the optimum counterweight in the double-sided fluff TENG (F-TENG) and transforms the mechanical energy into electrical energy. The optimal linkages of TENGs and EMGs are both specified as parallel, according to a series of theoretical analyses and experimental comparisons. As the result, the maximum volume power density of F-TENG and H-EMG is achieved at 2.02 and 16.96 W m(-3), respectively. The design of the double-sided fluff and the double Halbach array ensures the device's superior output at low frequencies while also increasing its endurance. Furthermore, the outputs of the FH-HG can power some small electronic devices and the Bluetooth transmission system to achieve the purpose of real time marine environmental monitoring. Overall, benefiting from the excellent structural design and distinctive operational mechanism, the FH-HG provides a remarkable candidate for harvesting wave energy on a large scale.