High-performance triboelectric nanogenerator based on natural silk fibroin and microstructured polytetrafluoroethylene for self-powered electronics and wearable sensing

Triboelectric materials and their surface morphology play a key role in improving the electrical output performance of triboelectric nanogenerators (TENG). Here, we reported a facile, low-cost, and eco-friendly TENG using silk fibroin (SF) and microstructured polytetrafluoroethylene (M-PTFE) as positive and negative triboelectric materials, respectively. SF is a natural, eco-friendly, and low-cost biopolymer and has a strong electron loss performance. Befitting its fluffy soft and biocompatible contact with human skin, it shows great potential for fabricating bio-TENGs. More remarkably, instead of adopting expensive lithography or complex etching techniques, microstructured PTFE (M-PTFE) is fabricated through a simple and cost-effective polishing technique using sandpapers with different meshes. The electrical output performance of TENG assembled by SF and M-PTFE was systematically evaluated, and the maximum peak-to-peak open-circuit voltage and short-circuit current to be 238 V and 12.6 μA could be achieved by TENG with 9 cm 2 area when polished with 40 meshes sandpaper. A relatively high output power density of 26.35 μW/cm 2 was obtained with an external 100 MΩ load resistor. Moreover, by introducing a rectifier bridge, TENG was employed to charge capacitors and drive portable electronic devices, such as clock, calculator and commercial light-emitting diodes (LEDs). Finally, TENG was successfully used to harvest biomechanical energy and realize human motion monitoring, demonstrating great potential as a self-powered multi-functional wearable sensing device.