Functional Fabric with Strain Sensing Based on Foam Finishing

Abstract
Strain sensing is one of the core parts of smart fabric which can be expressed by electrical signals affected by external forces. In this paper, the strain sensing functional fabric was prepared by using the acidified carbon nanotubes (a-CNTs) as the conductive layer and the waterborne polyurethane (WPU) as the adhesive based on foam finishing method. The results showed that many hydroxyl and carboxyl groups were introduced into the surface of CNTs through acidification, which improved their dispersibility in aqueous solution. The blended film of a-CNTs and anionic WPU had excellent conductive properties. When the ratio of a-CNT to WPU was 9:1, the fabric had the smallest resistivity, about 0.13 Ω⋅m, and the corresponding tensile sensing sensitivity up to 55.2.