Major concerns in the development of wearable textile electronics are exposure to moisture and contamination. The exposure can cause electrical breakdown of the device and its interconnections, and thus continuous efforts have been made to fabricate textile electronics which are free from moisture and pollution. Herein, we developed a highly conductive and waterproof fiber with excellent electrical conductivity (0.11 Ω/cm) and mechanical stability for advanced interconnector components in wearable textile electronics. The fabrication process of the highly conductive fiber involves coating of a commercial Kevlar fiber with Ag nanoparticle-poly(styrene- block-butadiene- block-styrene) polymer composites. The fabricated fiber then gets treated with self-assembled monolayer (SAM)-forming reagents, which yields waterproof and self-cleaning properties. To find optimal SAM-forming reagents, four different kinds of reagents involving 1-decane thiol (DT), 1 H,1 H,2 H,2 H-perfluorohexanethiol, 1 H,1 H,2 H,2 H-perfluorodecyltrichlorosilane, 1 H,1 H,2 H,2 H-perfluodecanethiol (PFDT) were compared in terms of their thiol group and carbon chain lengths. Among the SAM-forming reagents, the PFDT-treated conductive fiber showed superior waterproof and self-cleaning property, as well as great sustainability in the water with varying pH because of nanoscale roughness and low surface energy. In addition, the functionality of the conductive fiber was tested under mechanical compression via repeated washing and folding processes. The developed conductive fiber with waterproof and self-cleaning property has promising applications in the interconnector operated under water and textile electronics.
Keywords: E-textile; conductive fiber; self-assembled monolayer; self-cleaning; superhydrophobic; washable; waterproof; wearable device.