A highly sensitive, superhydrophobic fabric strain sensor based on polydopamine template-assisted synergetic conductive network

It is an enormous challenge to develop fabric sensors with wide sensing range, high sensitivity and stable sensing performance that can be employed to work in harsh conditions. Here, a superhydrophobic fabric strain sensor is successfully developed via constructing synergetic conductive networks (MWNTs (multi-walled carbon nano-tubes) and AgNPs (silver nanoparticles) on polydopamine (PDA) layer wrapped fibers, followed by poly-dimethylsiloxane (PDMS) coating. The synergetic conductive MWNTs/AgNPs networks render NWF/PDA/ MWNTs/AgNPs/PDMS (NPMAPS) strain sensor a wide sensing range of 120 % strain, high GF up to 527.1, minimum detection limit of 0.1 %, fast response time of 50 ms, and favourable sensing stability during stretching-releasing of 4000 cycles. PDMS with low surface energy combines with rough surface provided by MWNTs and AgNPs, which grants NPMAPS strain sensor satisfying superhydrophobicity (WCA = 156 degrees), self-cleaning ability and anti-corrosive resistance. Due to the high sensitivity and remarkable superhydrophobicity, the NPMAPS strain sensor can be utilized to detect small vibrations underwater (ultrasonic vibration and per-cussion) and joint motions even in humid or harsh environments. In addition, NPMAPS possesses low resistance of 1.55 omega cm-1, and thus exhibits a prominent electrothermal temperature (91.3 degrees C at 2.0 V). These significant performances demonstrate that the superhydrophobic NPMAPS is promising as waterproof wearable electronics.