Direct dip-coating of carbon nanotubes onto polydopamine-templated cotton fabrics for wearable applications

Simple and facile fabrication techniques to load conductive components onto textiles for wearable applications are highly demanded. In this work, highly conductive cotton fabrics were fabricated by dip-coating of single-walled carbon nanotubes (CNTs) after polydopamine (PDA) templating. The coated fabrics were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy and energy dispersive X-ray spectrum. The introduction of PDA enhanced the adhesion between fiber surface and the loaded CNTs, resulting in a conductivity of 41.5 Ω/sq for the coated fabrics. The CNT-PDA-cotton fabric showed great durability against repeated mechanical deformation (bending, folding) or multiple washing cycles. The excellent strain sensing performance of the coated fabrics granted them the application potential in real-time monitoring of different human motions such as speaking, drinking, walking, bending of finger and knee etc. Furthermore, the composite fabrics showed outstanding electric heating performance with a rise in the surface temperature to about 120 °C within 20 s at 6 V. The fabrication of CNT-PDA-cotton composite fabrics provides a novel and simple way of developing textile-based wearable electronics and heaters.