Evaluation of Breakdown Current Density of Carbon Nanotube Sheets and Their Composites for Lightning Strike Protection

Abstract

A combination of the high electrical conductivity, excellent mechanical properties and low density of carbon nanotubes (CNTs) suggests the potential of CNT-based materials to replace existing lightning strike protection technologies based on metal meshes. This study focuses on the development of a screening test method using the current carrying capacity (CCC) to evaluate CNT-based films and their composites. The method simultaneously provides breakdown current density (J ) and breakdown temperature. The testing setup consists of bowtie shaped coupons connected to a power source and carrying electricity until degradation of the sample causes a current drop. Normalization of J values to the volumetric mass density (specific J ) enables consideration of the potential weight savings with each material. The higher specific J of CNT-based films in comparison to existing standard materials based on metallic meshes suggests the advantage of CNT-based films for future development of a lighter protective layer against lightning strikes.