Enhanced electromechanical resilience and mechanism of the composites-coated fabric sensors with crack-induced conductive network for wearable applications

Conductive composites-coated fabric sensors are favorable sensing elements for wearable applications. However, rheology of composites ingredients has been causing inaccuracy due to high hysteresis and low instantaneity in real-time measurements. To address this problem, a composites-coated fabric-based strain sensor was fabricated and studied. A physical pretreatment scheme was designed to produce cracked surface morphology on the conductive composites film, yielding a stable conductive network. Results showed that this scheme can significantly lower the electrical hysteresis of the sensors by about 35% and effectively reduce electrical and mechanical relaxation, hence notably improved electromechanical resilience of the sensors. It is also found that the linear strain-resistance property of the sensors was largely retained after pretreatment. Sensing mechanism of the cracked sensors was further derived to understand the results. Through all the observations and application prospect demonstrated by two sensing belts, it is suggested that cracking can be considered to improve sensing performance for other coated fabric flexible sensors.