Thermal Drawing of Graphene-Integrated PVDF Fiber for Improved Performance in Wearable Triboelectric Nanogenerator

Triboelectric nanogenerators (TENG) exploit the phenomenon of triboelectrification enabling energy harvesting from low-frequency mechanical and biomechanical energy. Flexible ferroelectric polymers such as polyvinylidene difluoride (PVDF) are excellent candidates for fabricating a TENG device due to its high triboelectric charge density. Embedding 2D materials that have a high specific surface area into the PVDF matrix has proven to be an efficient strategy to affect surface morphology and friction property to improve the performance of TENG. Graphene and its derivatives have become a desired multi-functional material for fabricating high-performance TENGs. In this study, we demonstrate the successful fabrication of continuous PVDF graphene nanocomposite fiber via scalable thermal drawing process. Fibers were fabricated with varying concentration of graphene in the PVDF matrix (1 wt%, 3 wt% and 5 wt%) by optimizing the fiber drawing parameters. The 5 wt% graphene integrated PVDF TENG fiber generates peak power up to 12.08 µW, which is more than two times higher compared to pristine PVDF TENG (5.80 µW). This research will further expand our understanding on the dynamics of 2D nanomaterials into the polymer matrix of a thermally drawn fiber, leading to the performance optimization of wearable triboelectric devices and sensors.