Composite breakthrough: nano-coating boosts electrical and thermal conductivity

A nano-coating that is claimed to enhance the thermal and electrical conductivity of composites has been developed in a project involving academia and industry.

The collaboration between Bombardier and the Universities of Surrey and Bristol demonstrates that growing carbon nanotubes at high density - via chemical vapour deposition - on the surface of carbon fibre composites allows electrical transport throughout the material.

Dr Ian Hamerton, reader in polymers and composite materials in the University of Bristol’s Advanced Composite Centre for Innovation and Science (ACCIS), said: “This will have wide-reaching benefits in the aerospace industry, from enhancing de-icing solutions to minimising the formation of fuel vapours at cruising altitudes.”

For years, the application of composites in aerospace has been hindered by inherently poor electrical and thermal conductivities.

“The aerospace industry still relies on metallic structures, in the form of a copper mesh, to provide lightning strike protection and prevent static charge accumulation on the upper surface of carbon fibre composites because of the poor electrical conductivity,” explained Dr Thomas Pozegic, research associate at ACCIS. “This adds weight and makes fabrication with carbon fibre composites difficult.”

The new research, conducted at the University of Surrey’s Advanced Technology Institute (ATI) and the ACCIS, is said to show off the potential of carbon fibre reinforced plastics to be made multifunctional, while still maintaining structural integrity. Using this technique, sensors, energy harvesting lighting and communication antennae can now be integrated directly into the structure of the composite material.

Professor Ravi Silva, director of the ATI said: “In the future, carbon nanotube modified carbon fibre composites could lead to exciting possibilities such as energy harvesting and storage structures with self-healing capabilities. We are currently working on such prototypes and have many ideas including the incorporation of current aerospace/satellite technology in automotive design.”