A Conductive Bamboo Fabric with Controllable Resistance for Tailoring Wearable Sensors

Force-sensitive textile sensors are becoming a research hotspot as a part of wearable devices. The core research topic is the method to obtain the sensing property, which decides the sensitivity and service performance of the sensors. Here, we introduce a new sensing mechanism based on a statistical change of contact resistance that exhibits an exponential decay upon strain or pressure, where a novel conductive bamboo fabric is prepared and the dependence of electric conductivity on the fabric structure is discovered. The fabric surface resistivity (ρ_s) is anisotropic with respect to the measuring directions and the warp, weft, and linear densities. The surface resistance (R_s) decreases rapidly under pulling force, especially in diagonal directions, making it available in designing strain sensors. The volume resistivity (ρ_v) decreases with increasing weft and linear densities, too. The vertical resistance (R_v) decays exponentially under pressure, and the rule is retained even if the fabric is coated with a polymer, leading to diverse possible pressure sensors with a good service performance (e.g., waterproof). Finally, the conductive fabric could be facilely tailored to various wearable sensors with a fast response time, e.g., sensing finger sleeves and sensing insole, which could be used to operate the manipulator's fingers or to monitor human walking gestures, respectively.