| Abstract Scope |
Axially continuous graphene-copper (ACGC) composite wires–microscale copper wires coated with high-quality graphene–are high-performance conductors with ultrahigh conductivity. For practical applications, ACGC must undergo considerable mechanical deformation; however, their electromechanical response remains largely unexplored. This work investigates size-dependent electromechanical properties of ACGC. Using a customized tensile testing method, we characterize ACGC wires of 80, 25, and 10 μm diameters, showing 2.9%, 9.6%, and 13.8% reduced resistivity compared to pure copper wires, respectively. In addition, ACGC exhibits 31% higher ultimate tensile strength and 21% higher failure strain. Advanced materials characterizations using XRD, Raman spectroscopy, and SEM techniques reveal that damage to graphene occurs within localized plastic deformation regions. This highly localized damage preserves overall integrity of graphene and, therefore, maintains enhanced electrical conductivity up to fracture. Owing to the combined mechanical and electrical enhancement, ACGC wires show great potential for applications in flexible interconnects, wearable electronics, and high-power microchip transmission. |