Controllably Enhancing Stretchability of Highly Sensitive Fiber-Based Strain Sensors for Intelligent Monitoring

Abstract

Functional strain sensing is essential to develop health monitoring and Internet of Things. The performance of either narrow sensing range or low sensitivity restricts strain sensors in a wider range of future applications. Attaining both high sensitivity and wide sensing range of a strain sensor remains challenging. Herein, a cluster-type microstructures strategy is proposed for engineering high stretchability of highly sensitive strain sensor. The resistance change of the strain sensor is determined by the deformation of the cluster-type microstructures from close arrangement to orderly interval state during being stretched. Because of the unique geometric structure and conductive connection type of the sensing material, the strain sensor achieves a considerable performance that features both high sensitivity (gauge factor up to 2700) and high stretchability (sensing range of 160% strain). Fast response time and long-term stability are other characteristics of the strain sensor. Monitoring of multiple limb joints and controlling of audible and visual devices are demonstrated as the proof-of-concept abilities of the strain sensor. This study not only puts forward a novel design thought of strain sensor but also offers considerable insights into its potential value toward burgeoning fields including but not limited to real-time health monitoring and intelligent controls.

Application-Based Production and Testing of a Core–Sheath Fiber Strain Sensor for Wearable Electronics: Feasibility Study of Using the Sensors in Measuring Tri-Axial Trunk Motion Angles

“…The slower strain rate of 0.1 Hz did not show this phenomenon. Piezoresistive sensors have been reported that are able to track at higher strain rates, although they do not utilize polymer composites and rely on crack formation and decreased contact as the mechanism of piezoresistivity, avoiding this effect from the polymer mechanical properties [78]. If fast strain rates are required, the use of capacitive sensors are more appropriate, since they do not depend on the piezoresistive mechanism susceptible to rate-dependent hysteresis, and can sense accurately at strain rates upwards of 50% s −1 [79].…”

Human Motion Recognition of Knitted Flexible Sensor in Walking Cycle

“…Extracting the characteristic value by fitting the linear function or matrix and using calculus is relatively complicated and difficult. [9,11,15] In this work, the characteristic range value of the resistance, the calculation function of the peak value and the time comparison of the peak and valley point were used for evaluation.…”

“…Every material has its own conductivity; however, their working strain range is small and thus limits their practical application [8,13,14]. In the design of a strain sensor corresponding to human movement, the following key factors must be considered-large strain range, fast recovery deformation and high sensitivity [15][16][17]. Some special sensors (such as electromyographic signal) can be used to sense the activity of muscle and have great potential for human movement detection [5,18,19].…”

“…Strain sensors are one of the key components of the interface between human motion and electrical signals. Some highly sensitive strain sensors made of nanomaterial and graphene materials can detect small movements, such as vocal cord vibration detection, pulse detection and respiratory monitoring [15,19,24]. Conductive fabrics are a promising material due to their high flexibility, comfort to human skin and ease of weaving and integrability with other wearable sensors [25,26].…”

Wearable strain sensor for real-time sweat volume monitoring

“…Recently, by combining traditional textile technology with electrical engineering, e-textile has become an attractive candidate for wearable sensors ( Afroj et al., 2019 ; Hu et al., 2019 ; La et al., 2018 ; Wang et al., 2021 ; Zhao et al., 2019b ). Specifically, fiber strain sensors, known as the convergence of strain sensing materials (conductive materials) and textile platforms, have been used to monitor various human activities ( Gupta et al., 2018 ; Li et al., 2017 ; Liao et al., 2019 ; Yao et al., 2019 ).…”