A Synergistic Strategy through Microstructuring and Graphene Doping for High-Output Silk Fibroin-Based Triboelectric Nanogenerators toward Self-Powered Systems

The pursuit of sustainable and high-performance energy harvesters has driven growing interest in triboelectric nanogenerators (TENGs), yet challenges remain in balancing output enhancement, material biocompatibility, and fabrication simplicity. Herein, we report a high-efficiency silk fibroin–PTFE TENG engineered through finite-element simulations, structure optimization and graphene-assisted conductivity modulation. Biocompatible silk fibroin films were microstructured with well-defined pyramid and arch arrays in different microstructure densities, significantly increasing surface charge density and contact area. The optimized TENG with micro-arch silk fibroin achieved a peak-to-peak open-circuit voltage of 224 V and a short-circuit current of 12.74 μA, corresponding to over sixfold and threefold improvements, respectively, over TENGs without microstructure. Moreover, reduced graphene oxide (rGO) incorporation further enhanced the output performance of the TENG, with the peak-to-peak open-circuit voltage and short-circuit current reaching 288 V and 20 μA, respectively, resulting in additional improvements of 28.57% and 56.99%. Leveraging these advances, a 3 × 3 self-powered digital recognition array based on the silk fibroin/graphene-PTFE TENG demonstrated a recognition accuracy of 96.05%, validating its applicability in intelligent human-machine interfaces. This work presents a scalable and environmentally benign route to fabricating flexible TENGs with superior electrical performance and robust operational stability, bridging sustainable materials and advanced self-powered electronics.