An Eco-friendly Porous Nanocomposite Fabric-Based Triboelectric Nanogenerator for Efficient Energy Harvesting and Motion Sensing

A wearable and effective tribopositive material, especially an economical and eco-friendly triboelectric fabric developed from biomaterials, is highly crucial for the development of green wearable triboelectric nanogenerators. In this work, we design a porous nanocomposite fabric (PNF) with strong charge accumulation capacity through a facile dry-casting method and use it as a tribopositive material to construct attractive wearable triboelectric nanogenerators (abbreviated as TENGs). Specifically, the porous nanocomposite is developed by the incorporation of nano-Al₂O₃ fillers into cellulose acetate networks. By adjusting the concentration of casting solution and the content of nano-Al₂O₃ fillers, we systematically engineer the physical properties of the PNF for obtaining a large triboelectric charge yield. When a 10 wt % solution concentration and 10 wt % nanofiller content are adopted for the PNF, the corresponding PNF-TENG can deliver an electrical performance of ∼2.5 mW/cm² on a 0.8 MΩ external resistor. This remarkable output can be ascribed to the synergistic effect between the appropriate porous network and improved dielectric properties of the nanocomposite. Moreover, the PNF-TENG also exhibits good reliable electrical outputs under multiple stain-washing measurements or after experiencing cyclical contact-separation 13,500 times. Also, the device is capable of charging various capacitors, lighting LED arrays, and driving commercial wrist watches and is proven to be an efficient and reliable green wearable power source. Furthermore, a PNF-TENG-based elbow supporter and a grip ball, as self-powered sensors, are proposed to realize real-time detection for human actions during sports exercise. This work proposes an eco-friendly nanocomposite fabric as an effective tribopositive material, verifies the feasibility of developing environmentally friendly wearable power sources and sensors, and provides new insights into the design of green wearable triboelectric nanogenerators.