Design of MWCNTs and rGO co-decorated elastic core-spun yarn towards multifunctional flexible strain sensor with low detection limit and wide working range

In order to reduce the detection limit and improve the working range of flexible strain sensor, in this article, we reported a multi-walled carbon nanotubes (MWCNTs) and reduced graphene oxide (rGO) co-decorated multifunctional core spurn yarn flexible strain sensor (CGY FSS). It was found that the well lapping between MWCNT and rGO endows sensor with high working range (> 300%), while the helical structure of core-spun yarn makes it sensitive to very tiny deformation (0.1%). To improve its dynamic durability, polydopamine (PDA) was used to improve the interface bonding force between yarn and conductive materials, which ensures the sensor conduct stable electrical signals during 10,000 stretching cycles test at 10% strain. These features made it suitable for human motion detection and structural health monitoring. Moreover, due to the abundant carboxyl groups on the carbon material surface and the employment of polymer-based yarn, CGY FSS also showed good responsiveness to water vapor and acetone gas. It can be conceived that this as prepared strain sensor shows promising potential in smart device application with multiple response mechanism.