A pendulum-based nanogenerator for high-entropy wave energy harvesting

As a fundamental component of marine technology development, the energy supply for unmanned oceanic equipment faces constraints imposed by traditional power generation methods. In-situ wave energy harvesting has recently garnered increasing attention. Here, we present a chaotic pendulum-based energy harvesting mechanism designed to efficiently capture high-entropy and broadband wave energy. This approach departs from the conventional reliance on resonance to enhance wave energy converter performance, instead enabling the conversion of disordered wave energy into regular mechanical energy. The tower-integrated generator design, combined with a charge-excitation circuit, enhances wave energy capture, achieving peak power densities of 56.7 W/m³·Hz for the triboelectric nanogenerator and 192.3 W/m³·Hz for the electromagnetic generator. A wireless monitoring system is developed and validated through water tank experiments and open-sea trials. This work offers strong support for extending the operational endurance of unmanned marine equipment and facilitating the advancement of oceanic energy solutions.