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 for after composites are cured 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. Different electrode materials and the effects of their geometry variation on the CFRP to electrode interface resistance (IR) are studied experimentally. Finite element (FE) analysis is used to estimate the spread resistance (SR), providing a reliable estimation of the interface resistance between different electrodes and CFRP specimens. Copper is found to be the optimal electrode material and has a low interface resistance per unit electrode area ranging from 2.75×10 ^− 4 Ωmm ^− 2 to 1×10 ^− 3 Ωmm ^− 2 independent of geometry parameters. The mechanical bonding between the electrodes and the composite has been examined using pull-off tests and the obtained results show that the electrodes have an acceptable mechanical bonding with the composite layer. In comparison to other electrode fabrication processes, the co-curing technique is significantly easier, less invasive and more cost-effective as it eliminates the need for altering or introducing surface damage to CFRP specimens.