Multifunctional CNT and nylon hybrid fibers for thermal artificial muscles and self-sensing without bias voltage

Abstract

We present a thermo-driven coiled CNT@nylon fiber that combines actuation and self-sensing without external power. The coiled nylon core drives thermal contraction, while the CNT sheath converts deformation into electrical signals, producing open-circuit voltage variations up to 132.8 mV that directly indicate muscle motion. Under thermal stimulation at 60 degrees C, the fiber exhibited reversible contraction-relaxation with real-time monitoring. This multifunctional design integrates actuation and sensing at the material level, enabling compact, self-powered applications in soft robotics, wearable systems, and biointegrated electronics.