Robust Electrical Contact with Low Interface Resistance Using Embedded Co-cured Electrodes in Carbon Fibre Composites

Achieving robust low-resistance electrical contact with carbon fibres embedded in polymeric matrices is a challenge, and different electrode fabrication methods mostly post-curing the composite have been examined in the literature. This paper investigates the use of metallic foils co-cured on the top surface of carbon fibre reinforced polymer (CFRP) composites to form stable electrodes. The effects of different electrode materials and their geometric variations on the interface resistance (IR) between CFRP and electrodes are studied experimentally. Finite element (FE) analysis is used to estimate the spread resistance (SR), providing a reliable measure of IR for various electrode–CFRP configurations. Copper is found to be the optimal electrode material and has a low IR per unit electrode area ranging from 2.5 × 10 ⁻⁴ Ωmm ⁻² to 1 × 10 ⁻³ Ωmm ⁻² independent of geometric parameters. Pull-off tests demonstrate that the co-cured electrodes exhibit acceptable mechanical bonding with the composite layer. Compared to other electrode fabrication methods, the co-curing technique is significantly easier, less invasive and more cost-effective, as it eliminates the need to alter or induce surface damage in CFRP specimens.

Graphical Abstract