A conductive ternary network of a highly stretchable AgNWs/AgNPs conductor based on a polydopamine-modified polyurethane sponge

Abstract

A highly stretchable silver nanowires/silver nanoparticles (AgNWs/AgNPs) conductor based on a polydopamine (PDA) modified three dimensional polyurethane (PU) sponge was fabricated. The PU sponge skeleton was first modified by PDA to improve adhesion to the conductive nanomaterials. The conductive micro-network was fabricated by dip-coating of the PDA modified PU sponge into the solution of AgNWs, and AgNPs were further sputtered onto its surface to improve conductivity, resulting in a conductive ternary network structure. The resistance of the PDA–PU–AgNW–Ag–PDMS stretchable conductor decreased obviously with bending or stretching cycles initially, and then remained stable even up to 1000 cycles. The composites exhibit high electrical conductivity (exceeding 27.78 S cm⁻¹) and excellent electromechanical stability under high tensile strain (50%) owing to the combined effects from the ternary network. The significant electromechanical properties were also demonstrated by a simple stretchable circuit composed of a light-emitting diode (LED) and the stretchable conductor during bending, twisting or stretching.