A Stretchable, Highly Sensitive, and Multimodal Mechanical Fabric Sensor Based on Electrospun Conductive Nanofiber Yarn for Wearable Electronics

The development of highly sensitive, stretchable, and wearable electronic skin with multimodal mechanical-sensing performance is of great research value for applications in health monitoring, and wearable electronic devices. In this work, a fabric-like sensor with high flexibility and weavability that could detect the mechanical forces induced by pressure, strain, and flexion is designed. The fabric-like sensor is woven by composite yarns (GCNF@ECYs) formed by winding graphene oxide-doped polyacrylonitrile nanofiber yarns with in situ polymerized conductive polypyrrole on elastic yarns. The hierarchical structure of the fabric ranged from the macroscopic yarn to the submicron-scale fibers to the nanometer-scale particles as well as the wrapped structure constructed by winding conductive nanofiber yarn on elastic yarn. This offers more conductive pathways, larger deformation space, and multimodal mechanical-sensing capabilities. The GCNF@ECY sensor unit has high sensitivity (the gauge factor was ≈68), wide pressure-sensing range, excellent cycling stability, and good repeatability (over 10 000 cycles). The sensor can detect human respiration, facial expressions, pulse monitoring, and a full range of human motion. Moreover, the fabric sensor can be easily woven into textiles to produce electronic textiles with great potential in wearable human health monitoring electronics devices.