A Conductive Bamboo Fabric with Controllable Resistance for Tailoring Wearable Sensors

ACS Appl Mater Interfaces. 2022 Jun 6. doi: 10.1021/acsami.2c04192. Online ahead of print.

Abstract

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 (ρs) is anisotropic with respect to the measuring directions and the warp, weft, and linear densities. The surface resistance (Rs) decreases rapidly under pulling force, especially in diagonal directions, making it available in designing strain sensors. The volume resistivity (ρv) decreases with increasing weft and linear densities, too. The vertical resistance (Rv) 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.

Keywords: anisotropic electric resistance; conductive bamboo fabric; contact resistance; fabric structure deformation; wearable sensor.