Isotropically\nPolarized Bipiezoelectric Polyacrylonitrile-Poly(vinylidene\nFluoride) Advanced Triboelectric Nanogenerator for Operation in High-Humidity\nEnvironments

Conventional\nhybrid piezo-triboelectric nanogenerators (PTNGs)\nhave potential applications as energy supply devices for microelectronic\ndevices, but their low power density and unstable performance under\nhigh-humidity conditions are challenges that need to be solved. Here,\nwe report a novel flexible hybrid bifiezo-triboelectric nanogenerator\n(Bi-PTNG) based on isotropic polarization design of piezoelectric\nPVDF and PAN nanofiber membranes, which greatly improves power density\nof devices and performances in high-humidity conditions. The performance\nenhancement mechanism of the Bi-PTNG was investigated by model analysis,\nexperimental measurements, and simulations. The results showed that\nthe power density output of Bi-PTNG increased by approximately 88%\ncompared to that of a depolarized PAN/PVDF-based triboelectric nanogenerator\n(TENG). The application studies demonstrated that a 2 × 2 cm<sup>2</sup> Bi-PTNG can be directly used to run more than 120 commercial\nLEDs, and this highly flexible and breathable all-fiber device can\nbe integrated into clothing or insoles to monitor human movement in\nhigh-humidity conditions. This work not only provides an effective\nstrategy for enhancing the power output of TENGs and advancing their\npractical applications but also offers robust guidance for the material\nselection and optimization of the polarization direction in such nanogenerators.