An Electromechanical Power Law in Sustainable Thermally Drawn Triboelectric Nanocomposite Fibers for Sensing in Continuum Robots

The development of self-powered and sustainable tactile sensors requires scalable materials that integrate electromechanical coupling, environmental compatibility, and high precision. Here, we report a universal electromechanical scaling law governing the voltage–force response in triboelectric nanogenerators (TENGs), established through sustainable SnO2 integrated polyvinylidene fluoride nanocomposite fibers fabricated via a thermal fiber drawing technique. The fibers exhibit enhanced crystallinity and interfacial polarization, yielding an open-circuit voltage of 37.2 V and a short-circuit current of 36.25 μA, with a corresponding peak power of 32.1 μW (243 mW m–2) under cyclic mechanical excitation. Beyond performance gains, the extracted force-dependent power law provides a transferable framework to benchmark and compare soft TENG fibers across loading conditions, addressing a major gap in standardized sensitivity metrics. Moreover, the resulting devices demonstrate long-term durability (>16,000 cycles) and exceptional sensitivity in robotic tactile and continuum actuation systems. Integration of the fibers into continuum robotic platforms enabled self-powered tactile sensing and rapid collision detection in free-space and in-pipe scenarios, achieving response times under 25 ms. This study establishes a physics-based framework for soft triboelectric systems, merging sustainable nanomaterials, scalable fiber processing, and universal electromechanical laws, paving the way toward self-powered, ecoconscious robotic and wearable interfaces.