Design and fabrication of a flexible woven smart fabric based highly sensitive sensor for conductive liquid leakage detection

Abstract

A woven fabric based sensor is fabricated for detection of conductive liquid leakage at trace levels. The working principle of the sensor is based on the structure of the fabric. The fabric's body is mainly composed of nonconductive yarns, and two groups of conductive warp yarns are arranged in the same selvage of the fabric. Furthermore, the fabric has many conductive weft yarns, which interlace with one of the two groups of conductive warp yarns and are separate from the other one. When the conductive liquid is absorbed by the fabric, nonconductive yarns will become conductive, and an electrical connection will be formed between adjacent conductive weft yarns and the two groups of conductive warp yarns. With this structure, the fabric based sensor could quickly detect as little as one drop of liquid (about 0.05 mL). Moreover, the fabric could be cut along its warp or weft direction without damaging its detection function, which allows it to be tailored flexibly for practical use. Besides, investigations on the selection of yarns revealed that chemical multifilament selected as the nonconductive yarn could bring about faster response due to its better wicking property. The fabric based sensor could become one part of an online detecting system for industrial leakage and medical monitoring.