Radial-Grating Pendulum-Structured Triboelectric Nanogenerator for Energy Harvesting and Tilting-Angle Sensing

A radial-grating pendulum-structured triboelectric nanogenerator (RP-TENG) is demonstrated for energy harvesting and tilting-angle sensing. By employing the pendulum structure, the RP-TENG is applied to capture biomechanical energy from human motion or harness the energy in acceleration or deceleration processes of moving vehicles. The electrical performance of the RP-TENG is systematically studied by simulating the repetitive movement of human arms and legs during walking at different repetition frequency. At the resonance frequency of 1.5 Hz, the open-circuit voltage (V_OC) and short-circuit current (I_SC) produced are 83.6 ± 0.5 V and 8.46 ± 0.08 µA, respectively, and the maximum instantaneous power density is 35.2 mW m⁻² at a load resistance of 10 MΩ. Through parallel-connecting 4 pairs of triboelectric layers, the I_SC can be increased from 4.45 µA for one pair of triboelectric layers to 12.83 µA. Furthermore, owing to its high sensitivity to minor changes from the vertical level (the lower detection limit of the RP-TENG is 0.25°), a RP-TENG integrated tilt sensing alarm system is developed, which can be applied in security or seismic monitoring systems.