A wearable strain sensor for medical rehabilitation based on piezoresistive knitting textile

Abstract

Flexible sensors are attracting attention for their possible applications in the medical field. However, it often requires complex preparation processes and expensive materials, especially in the preparation of sensitive layers. This enables better sensing performance and a wider range of applications, but also limits its production. Here, we developed a flexible strain sensor based on piezoresistive knitted fabrics and polydimethylsiloxane (PDMS). The materials employed obviate the necessity for intricate preparation procedures and are cost-effective, holding the potential for achieving economies of scale in production. The knitted fabrics were made of conductive silver-plated nylon filaments and spandex-covered yarns, both with good stretchability, as the sensitive layer. The fabrics can be mass-produced in industrial facilities, and the curing process for PDMS is simple, increasing the producibility of sensors for applications. This strain transducer has a good sensing range (0 %-87 %) and Gauge Factors (10.6), while also exhibiting excellent durability (5000 cycles). The proposed sensor can successfully detect a range of human movements, demonstrating potential application in the areas such as smart wearable devices and medical rehabilitation.