An airflow-driven system for scalable production of nano-microfiber wrapped triboelectric yarns for wearable applications

Nanofibers, with their large aspect ratio, high specific surface area, and high porosity, hold great promise for applications in textile materials, biomedicine, and smart wearables. Currently, the primary method for producing nanofibers is electrospinning. However, this method carries operational risks due to the use of high-voltage electrostatic fields, and it is not suitable for large-scale production due to low efficiency. To address these challenges, we propose an air-driven spinning system that combines solution blow spinning and vortex tubes for the scalable production of polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) nano-microfiber wrapped conductive yarn. The airbrushing machine allows for high-speed production of PVDF-TrFE nano-microfibers through solution blow spinning, with a maximum production rate of approximately 36 ml/h. The vortex tubes apply rotation and twist to the core yarn using high-speed airflow to bond the nano-microfibers to core yarn. By optimizing the process, we achieve a tight integration between the outer layer of nano-microfibers and the inner layer of conductive core yarn, imparting water repellency, flexibility, washability, air permeability, and a certain level of abrasion resistance to the resulting yarn. We demonstrate the applications of this yarn as triboelectric nanogenerators, including energy harvesting and self-powered sensing. Furthermore, we employ this method to prepare stretchable self-generating triboelectric yarn. This air-driven spinning system overcomes the limitations of electrospinning, providing a scalable and efficient method for the production of nano-microfiber-wrapped yarns with various functional properties.