Ultrasensitive Strain Sensor Based on Pre-Generated Crack Networks Using Ag Nanoparticles/Single-Walled Carbon Nanotube (SWCNT) Hybrid Fillers and a Polyester Woven Elastic Band.

Yelin Ko,Jooyong Kim,Ji-Seon Kim,Chi Cuong Vu

doi:10.3390/s21072531

Abstract

Flexible strain sensors are receiving a great deal of interest owing to their prospective applications in monitoring various human activities. Among various efforts to enhance the sensitivity of strain sensors, pre-crack generation has been well explored for elastic polymers but rarely on textile substrates. Herein, a highly sensitive textile-based strain sensor was fabricated via a dip-coat-stretch approach: a polyester woven elastic band was dipped into ink containing single-walled carbon nanotubes coated with silver paste and pre-stretched to generate prebuilt cracks on the surface. Our sensor demonstrated outstanding sensitivity (a gauge factor of up to 3550 within a strain range of 1.5–5%), high stability and durability, and low hysteresis. The high performance of this sensor is attributable to the excellent elasticity and woven structure of the fabric substrate, effectively generating and propagating the prebuilt cracks. The strain sensor integrated into firefighting gloves detected detailed finger angles and cyclic finger motions, demonstrating its capability for subtle human motion monitoring. It is also noteworthy that this novel strategy is a very quick, straightforward, and scalable method of fabricating strain sensors, which is extremely beneficial for practical applications.

Highlights

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Flexible and stretchable strain sensors have seen a rapid rise in demand because of their roles in monitoring physical activities, as well as health-related variables, such as body motions [1], human expressions [2], breathing [5], and pulse [6]
Various types of novel strain sensors have emerged based on changes in their electrical characteristics in response to mechanical deformations, which can be described as resistive [1,6], capacitive [7], or piezoelectric [8]

Summary

Introduction

Wearable electronics have attracted tremendous attention for their potential applications in effective interactions between humans and smart systems, including personal healthcare, human–machine interfaces, and electronic skins [1,2,3,4,5,6,7,8]. Flexible and stretchable strain sensors have seen a rapid rise in demand because of their roles in monitoring physical activities, as well as health-related variables, such as body motions [1], human expressions [2], breathing [5], and pulse [6]. Various types of novel strain sensors have emerged based on changes in their electrical characteristics in response to mechanical deformations, which can be described as resistive [1,6], capacitive [7], or piezoelectric [8]

Methods

Discussion

Conclusion