Highly Sensitive Textile Pressure Sensors With Novel Hierarchical Architecture Based on Conductive Polymers, Silver Nanoparticles and Carbon Nanotubes

Abstract

Herein, we designed wearable, flexible, highly sensitive textile-based pressure sensor assemblies utilizing a piezoresistive working mechanism. The sensor assemblies were constructed using a composite of coated cotton woven or polyester knitted fabric encapsulated and stitched between two layers of polypropylene spunbond nonwoven fabric embroidered with stainless steel yarn serving, creating a robust and integrated sensing structure. As a component of the sensor assemblies, the cotton and polyester fabrics were subjected to a series of surface modifications involving coating with silver nanoparticles, a silica xerogel film formation through a sol-gel process, application of polypyrrole via chemical oxidative polymerization, followed by deposition of a layer of carbon nanotubes and polydimethyl siloxane utilizing a dip-coating method. The sensor assemblies employing conductive polyester knitting fabrics demonstrate remarkable sensing capabilities, including an extensive sensing range of 0 kPa-225 kPa, high sensitivity values of 30 kPa(-1), low detection limits of 125 Pa, fast response-recovery times of 120-80 ms and robust sensing stability exceeding 1000 cycles, respectively. Moreover, the sensor assemblies exhibited significant promise for real-time human motion monitoring, encompassing activities such as finger, wrist, elbow and knee bending; swallowing, walking and jumping. These sensor assemblies offer distinct advantages, including cost-effectiveness, ease of handling, straightforward production methods, and an environmentally friendly fabrication process.