Material selection and performance optimization strategies for a wearable friction nanogenerator (W-TENG)

With developments in science and technology, wearable electronic products are increasingly used in daily lives. The growing demand for energy highly necessitates developing new energy sources. As a modification of traditional friction nanogenerators (TENGs), wearable friction nanogenerators (W-TENGs) can convert mechanical energy from human movements into electricity. The working principle and primary working mode of the W-TENG are elucidated in this paper. The triboelectric materials commonly used for W-TENGs are selected based on the type of friction materials to achieve a better triboelectric output. To improve the triboelectric output, some optimization suggestions for triboelectric materials are put forward: increasing the surface charge density and reducing the decline in triboelectric charge to enhance the output performance of the W-TENG fundamentally. Finally, the prospects and challenges of the W-TENG are analyzed, and it is hoped that this review can promote the development of the W-TENG and provide clean and sustainable energy solutions for wearable bioelectronic systems. This review summarizes the research progress of wearable friction nanogenerators (W-TENG). Its perspective comprehensively covers the friction layer, the electrodes, and strategies for improving the triboelectric output of the W-TENG.