Analysis of Sensitivity, Linearity, Hysteresis, Responsiveness, and Fatigue of Textile Knit Stretch Sensors

Abstract

Wearable technology is widely used for collecting information about the human body and its movement by placing sensors on the body. This paper presents research into electronic textile strain sensors designed specifically for wearable applications which need to be lightweight, robust, and comfortable. In this paper, sixteen stretch sensors, each with different conductive stretch fabrics, are evaluated: EeonTex (Eeonyx Corporation), knitted silver-plated yarn, and knitted spun stainless steel yarn. The sensors’ performance is tested using a tensile tester while monitoring their resistance with a microcontroller. Each sensor was analyzed for its sensitivity, linearity, hysteresis, responsiveness, and fatigue through a series of dynamic and static tests. The findings show that for wearable applications a subset of the silver-plated yarn sensors had better ranked performance in terms of sensitivity, linearity, and steady state. EeonTex was found to be the most responsive, and the stainless steel yarn performed the worst, which may be due to the characteristics of the knit samples under test.

Smart Textile‐Based Personal Thermal Comfort Systems: Current Status and Potential Solutions

“…When considering wearable sensors, it is desirable that the sensors are highly sensitive (large change in the output signal with small change in the measurand), biocompatible, lightweight, and are capable of providing a large sensing range, low hysteresis as well as fast response and recovery times [316,317] meaning the sensor should respond quickly when there is a change in the stimuli of interest and return to baseline signal when the stimuli is no longer present. [318] Most importantly, it is necessary that the sensors are mechanically compatible with the body while also being highly stretchable in order to conform to biological tissues, including at high flexion points like joints. [305] This poses a serious challenge when it comes to creating wearable temperature and humidity sensors because most materials undergo a change in electrical conductivity when deformed.…”

Design of Textile Knitted Stretch Sensors for Dance Movement Sensing

“…We analysed the sensitivity, linearity, hysteresis, responsiveness, and fatigue of textile knit stretch sensors as described in [6]. Among the sixteen textile stretch sensors, a silver-plated sensor using conductive fabric material Technik-tex P130B met the sensor requirement for dance movement sensing the best.…”

“…To design and make a reliable stretch sensor that can integrate into a dance bodysuit for dance movement sensing, we compared the properties of different conductive materials [6] and tested the bonding technique and sensor's washability [7].…”

Fatigue Testing of Wearable Sensing Technologies: Issues and Opportunities

“…Disruption of electrical continuity or a 150% rise in the resistance over the initial resistance value constitutes failure [ 74 ]. While researchers are working to standardize testing methodologies for some internal wearable sensors [ 74 ], fatigue testing methods for external wearable sensors are not standardized [ 40 ], and a variety of testing methodologies, rates, and cycling regimes have been reported in the fatigue testing of proposed wearable sensors [ 6 , 11 , 12 , 13 , 20 , 21 , 30 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 ].…”