Room-temperature self-healing elastomer-graphene composite conducting wires with superior strength for stretchable electronics

Stretchable conductive materials are essential to realize wearable electronic devices, soft robotics, and implantable electronics. However, developing high-performance conductive materials integrated with exceptional mechanical properties, large stretch ability, room-temperature self-healing is still a key challenge. Here, we demonstrate a novel design strategy to fabricate an amphiphilic copolymer elastomer with superior mechanical properties and room-temperature healing efficiency. The synergy of reversible hydrogen bonds and microphase-separated structures enables the resultant elastomer with excellent mechanical strength and high healing efficiency. Furthermore, self-healing and stretchable composite conducting wires are fabricated based on the coiled bilayer film, which is comprised of the elastomer matrix and the ultrathin wrinkled graphene layer. The optimum composite wires show superior strength of 9.3 MPa, high conductivity of 120 S cm⁻¹, large extensibility of 300%, healable efficiency of over 80%. Moreover, it is demonstrated that the composite wires can be used as a strain sensor to monitor tensile deformation and human motion. The strain sensor can maintain good stability under 20 cycles of stretching/releasing with 300% strain. This work may provide a facile approach to design tough self-healing conductive materials for next-generation wearable electronics.