Flexible and wearable strain sensing fabrics

Flexible electronic devices have attracted considerable attention in recent years. Textile fabrics have been widely used to fabricate flexible strain sensors owing to their high flexibility. However, the elasticity of ordinary textile fabrics is low, which limits their strain sensing range. In this article, we used a simple method to fabricate flexible strain sensing fabrics (FSSFs) through the coating of graphene oxide (GO) nanosheets on elastic nylon/polyurethane (nylon/PU) fabric, followed by reduction of GO with sodium borohydride. The reduced graphene oxide (RGO) nanosheets were adsorbed on the elastic fabrics to impart electrical conductivity to the fabrics. The coated fabrics were characterized with scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Raman scattering spectroscopy. The electromechanical performance and strain sensing properties of the FSSF were investigated. The fabricated strain sensor exhibited high sensitivity, a large workable strain range (0–30%), fast response and great stability. The mechanical property of fabrics did not change remarkably after the treatment with RGO. The surface resistance of the RGO/nylon/PU only increased from ∼112 KΩ/m² to ∼154 KΩ/m² after 8 washing cycles, exhibiting good washability. Furthermore, real-time monitoring of human motions, such as bending of finger and rotation of wrist, was achieved by the as-prepared FSSF. The RGO/nylon/PU fabrics as flexible strain sensors have potential applications in wearable electronic devices.