Highly stretchable strain sensor with tunable sensitivity via polydopamine template-assisted dual-mode cooperative conductive network for human motion detection

Abstract

Incorporating conductive fillers into the fabric structure as the strain sensor for wearable smart devices has attracted considerable attention recently. However, the cooperative work between textiles and conductive materials is still a huge challenge, with particular reference to the development of stable strain sensors based on rGO-decorated polyester fabrics with the superb balance between tunable sensitivity and subtle- and large-scale workable strain ranges. In this study, a proposed strain sensor with the laminated structure containing a co-conductive network comprising reduced graphene oxide (rGO)@ polydopamine (PDA) and silver nanoparticles (AgNPs)@carboxylated carbon nanotubes (CNTs-COOH) composite layers was fabricated via a facile layered generating technique. Interestingly, rGO and AgNPs@CNTs-COOH were successfully grown onto the PDA-templated poly (ethylene terephthalate) (PET)/polyurethane (PU) fabric (PPPF) respectively. Furthermore, it demonstrated impressive performances in terms of tunable sensitivity (0–549.78), suitable stability under various strain ranges, superb electrical conductivity, wonderful durability over 2000 cycles, broad workable strain range (0–240%), and remarkable electrical heating property. Importantly, the proposed strain sensor was investigated to be used for human motion detection including tiny human movements and robust body motions, as well as temperature detection, implying its further favorable application in flexible wearable devices.

Keywords

• Polydopamine
• Flexible strain sensor
• Dual-mode cooperative conductive network
• PET/PU fabric
• Electrical heating property
• Human motion detection