3-D woven triboelectric nanogenerators with integrated friction, spacer, and electrode layers for wearable energy harvesting and mechanical sensing

Textile-based triboelectric nanogenerators (T-TENGs) inject new vitality into smart wearable electronic textiles (e-textiles) with low power consumption and high flexibility due to their excellent shape adaptability. However, most t-TENGs are fabricated using physical or chemical processes to give the materials specific properties, with the disadvantages of high material requirements, complex and time-consuming fabrication processes, and impact on the comfort of the textiles. In this study, a three-dimensional woven triboelectric nanogenerator (3DW-TENG) with integrated friction, spacer, and electrode layers was fabricated by using a three-dimensional weaving technology. By combining experimental testing and theoretical analysis, the study investigated the impact of the arrangement of friction materials and the number of friction layers on the performance of the 3DW-TENG. At a frequency of 1 Hz and under an external force of 30 N, the open-circuit voltage, short-circuit current, and peak power density of the 3DW-TENG reached 9.38 V, 31.65 nA, and 2.16 × 10^-2 mW/m². The three-dimensional fabric structure gave it better integrity and stability. In addition, the 3DW-TENG exhibited excellent flexibility and sensitivity, which allowed for better integration with textiles. It was capable of converting mechanical energy into electrical energy and powering micro-devices. It could also sensitively detect the bending and changes in the motion state at important joints. When placed at the sole of the foot, it could serve as a self-powered pressure sensor to identify changes in foot pressure. This work provides greater development space for the potential applications of flexible self-powered textiles in the fields of wearable electronics and personalized healthcare.