Humidity sensing properties of multi-walled carbon nanotube/polyvinyl alcohol composite yarn

• 1、Textile School, Donghua University, Shanghai, 201620

Abstract：The research of flexible sensor gets more and more attention. It is easy to operate, light and has good biocompatibility, etc. A yarn-like switch-type humidity sensing material is fabricated by infiltrating hydrophilic water-swellable polyvinyl alcohol (PVA) into a multi-walled carbon nanotube (MWCNT) yarn. The electrical resistance of the virgin humidity sensing material remains almost constant at low relative humidity (RH), and then increases sharply as the RH increases above 75%, showing a good humidity switch characteristic. The sensitivity of the sensing material can reach up to 1.89 at 100% RH. Humidity sensitive characteristic is mainly result from the swelling of PVA of composite yarns at high humidity. The promising multi-functional material may be used for real-time RH switch monitoring in flexible electronic devices, such as in intelligent textiles and other industrial applications.

Keywords： Textile materials Carbon nanotube yarn Humidity switch material Flexible sensor Electrical resistance