A flexible humidity-resistant nanofiber-based triboelectric nanogenerator with high electrical output stability as self-powered sensors for motion monitoring

Abstract

Triboelectric nanogenerators (TENGs) have been widely used to harvest irregular mechanical energy generated by human activities to power low-power wearable electronic devices due to their excellent electrical output performance, simple structure, high portability, and low cost. However, ambient humidity can significantly affect the surface charges of triboelectric materials and the electrical output stability of TENGs, which greatly limits their application. Herein, we designed a flexible humidity-resistant TENG with excellent electrical output stability based on zinc oxide nanorods@polyacrylonitrile (ZnO@PAN) nanofiber membrane modified with 1H,1H,2H,2H-Perfluorooctyltriethoxysilane (POTS). ZnO nanorods and POTS modification enhanced surface friction and the electrical output performance of the TENG in high humidity environments. The power density of as-prepared TENG reached 270.6 μW/cm² at the load resistance of 3.5 MΩ. Moreover, compared with the ZnO@PAN-based TENG, this humidity-resistant TENG showed lower electrical loss and shorter recovery time in the humidified state. It also exhibited excellent electrical output stability under the influence of continuous humidification. The pulse electrical signal generated by this humidity-resistant TENG could intermittently light up 54 LEDs at a relative humidity of 80 %. Furthermore, the POTS/ZnO@PAN-PDMS TENG was used as a self-powered sensor for motion monitoring and haptic sensing in an environment with a relative humidity of 70 %, which exhibits good electromechanical conversion performance and motion monitoring capability in high humidity environments, greatly broadening the application range of TENGs.