Carbon Nanofiber-Regulated PVDF/PMMA Electrospun Nanocomposite Tribonegative Membranes for Enhanced Triboelectric Output and Flexible Self-Powered Sensing

Abstract Electrospun tribonegative membranes are essential components of flexible triboelectric nanogenerators because their fiber morphology, surface composition, and interfacial contact strongly affect device output. Here, a flexible contact–separation TENG was constructed using an electrospun PVDF/PMMA/CNF membrane as the tribonegative layer and an electrospun TPU membrane as the tribopositive layer. Although PVDF is widely used as a tribonegative material, its fibrous contact interface still requires structural regulation. PMMA was introduced to improve network continuity, while CNF loading regulated the fiber morphology and dielectric response without compromising membrane integrity. At 20 N and 0.5 Hz, the optimized PPC-3 TENG, fabricated using a PVDF/PMMA/CNF membrane containing 3 wt % CNF as the tribonegative layer, generated approximately 101 V and 40 nC, compared with 40 V and 17 nC for the PVDF/PMMA-based TENG, corresponding to increases of approximately 153% and 135%, respectively. Its maximum open-circuit voltage reached 180 V at 30 N, and the device successfully lit multiple commercial LEDs. The optimized PPC-3 TENG maintained a stable output after 10,000 contact–separation cycles under an applied force of 20 N and after 4 weeks of storage. It also generated distinguishable signals during arm bending, hand pressing, and foot stepping. This work provides a simple strategy for regulating electrospun tribonegative interfaces and developing flexible self-powered motion sensors.