Thermal drawing of MoS₂ integrated PVDF triboelectric fiber for continuous respiration monitoring

Abstract

Triboelectric nanogenerators (TENGs) are environmentally sustainable energy harvesting devices that can convert mechanical and biomechanical energy into electrical output through the synergistic process of triboelectrification and electrostatic induction. Incorporating polyvinylidene fluoride (PVDF) and its copolymers into flexible TENG is particularly advantageous because of the abundance of highly electronegative fluorine ions and high dielectric constant. MoS₂ can interact with PVDF dipoles to improve PVDF's β phase content, thereby improving the triboelectric property of the polymer nanocomposite fibers. In this study, thermally drawn PVDF TENG fibers are fabricated, incorporating various concentrations of $MoS_2$ for the first time. The enhanced β phase property in the nanocomposite fiber improves the triboelectric output where 3 wt.% $MoS_{2-}$ PVDF fiber demonstrates a maximum peak power output of 17.64 µW, exhibiting a threefold increment compared to 0 wt.% $MoS_{2-}$ PVDF fiber. Simultaneous integration of multiple nanomaterials ($MoS_2$ and graphene) is also investigated to analyze the triboelectric fiber's β phase formation and electrical performance. Harnessing the superior sensitivity of the $MoS_2$ integrated triboelectric fiber, a self-powered wearable mask is designed for continuous human respiration monitoring.