A Machine-Braided Iontronic Pressure-Sensing Yarn for Wearable Sensitive Pressure Detection and Human Movements Monitoring

While fiber-shaped pressure sensors are promising for wearable electronics owing to their lightweight and high integrability, developing a simple and large-scale fabrication strategy to achieve their ideal performance remains a key challenge. In this work, a high-performance, yarn-shaped capacitive (YSC) pressure sensor is developed through a continuous fabrication technique, during which process a bilayered composite yarn with a “nanofiber dielectric sheath and conductive core” structure is braided around conductive yarn to construct a capacitive pressure-sensing structure. The sensing performance of the YSC pressure sensor are improved by an ionic-liquid-doped P(VDF-HFP) nanofiber dielectric layer, which creates an iontronic sensing mechanism, yielding high sensitivity, fast response, wide detection range, and reliability. The sensor demonstrates its capability for developing intelligent textiles for wearable sensitive tactile detection and human motion monitoring, as well as, notably, for strain-insensitive pressure detection under stretching.