Comb-structured triboelectric nanogenerators for multi-directional energy scavenging from human movements

A triboelectric nanogenerator (TENG) is an emerging energy harvesting technology utilizing multi-directional, wasted mechanical energies stemming from vibrations, winds, waves, body movements, etc. In this study, we report a comb-structured TENG (CTENG) capable of effectively scavenging multi-directional motions from human movements, which include walking, jumping, and running. By attaching CTENG to a person’s calf, we obtain a root-mean-square (RMS) power value of 5.28 μW (i.e. 13.12 V and 0.4 μA) for 1 s during mild running action (~5 m/s), which is sufficient for powering 10 light emitting diodes (LEDs). We integrate a CTENG with a simple hand-held pendulum (HHP) system with a natural frequency of 5.5 Hz. The natural frequency and input energy of our HHP system can be easily controlled by changing the holder mass and initial bending displacement, thus producing different output behaviors for the CTENG. Under the optimal HHP-based CTENG system design, the maximum output reaches 116 V at 6.5 μA under 0.1 kg mass and 4 cm bending displacement conditions. The corresponding output energy is 52.7 μJ for an operation time of 10.8 s. Our HHP-CTENG system can sufficiently power 45 LEDs and shows different output performances by varying the driving velocity of a vehicle, thus demonstrating the possibility for a self-powered velocity monitoring system.

摩擦纳米发电机（triboelectric nanogenerator, TENG）是一种新兴的能量收集技术，可利用振动、风能、波浪能、人体运动等来源的多方向废弃机械能。本研究报道了一种梳状结构摩擦纳米发电机（comb-structured TENG, CTENG），其能够有效收集人体运动产生的多方向机械能，涵盖行走、跳跃与奔跑等动作。将该CTENG附着于人体小腿处，在时速约5 m/s的轻度奔跑动作下，1秒内可获得5.28 μW的均方根（root-mean-square, RMS）功率值（对应输出电压13.12 V、电流0.4 μA），足以驱动10个发光二极管（light emitting diodes, LEDs）。我们将CTENG与固有频率为5.5 Hz的简易手持摆（hand-held pendulum, HHP）系统进行集成，通过改变配重质量与初始弯曲位移，可灵活调控该HHP系统的固有频率与输入能量，从而使CTENG产生不同的输出特性。在基于HHP的CTENG系统最优设计下，当配重质量为0.1 kg、初始弯曲位移为4 cm时，其最大输出可达116 V、6.5 μA，在10.8 s的工作时长内对应输出能量为52.7 μJ。本HHP-CTENG系统可稳定驱动45个发光二极管，且通过改变车辆行驶速度可实现差异化输出性能，从而验证了其应用于自供电速度监测系统的可行性。