Tiny buoy-immense wisdom: Self-powered and self-sensing sundae cup-shaped wave energy harvester for smart oceans

The piers of the sea-crossing bridges have been submerged and eroded for an extended period, presenting a significant safety hazard. Therefore, unmanned monitoring equipment is urgently needed in the waters near the pier. Waves can be harnessed as an abundant renewable energy source. Furthermore, because of the bridge pier's diversion effect, the primary direction of water flow is comparatively stabilized, whereas the pendulum's continuous movement necessitates input excitation in a specific direction. Consequently, this study proposes the development of a self-powered and self-sensing intelligent buoy, employing an inertial pendulum and TENG (Triboelectric nanogenerator) monitoring system to facilitate long-term monitoring of hydrological conditions. The intelligent buoy is divided into two modules based on their respective functionalities: the self-powered module located in the lower section and the self-sensing module positioned in the upper section. The self-powered module comprises three elements, including a wave energy capture part, a motion conversion part, and an electromagnetic energy conversion part. The signal processing part serves as the centerpiece of the self-sensing module. After experimental testing, the maximum power of a single prototype can reach 12.11 mW, and the accuracy of abnormal monitoring can exceed 90%. The Six-DOF (six-degree-of-freedom) shaker experiments and LSTM (Long Short-Term Memory) algorithm-based processing show that the dual-function intelligent buoy is an innovative feasible scheme to realize the IoTs.