Carbon nanotube coatings for thermal control

Materials based on carbon nanotubes (CNT) with their high thermal conductivity, the high aspect ratios as well as their mechanical strength, provide innovative materials for thermal control applications such as improved thermal interfaces. We demonstrate the feasibility of carbon nanotube based systems for use in thermal control applications, e.g. as a contact layer between two thermally connected materials. Multi-wall carbon nanotube (MWCNT) arrays of different density and length have been grown on silicon and copper surfaces using chemical vapor deposition. Measurements of the heat flow across different surfaces demonstrates that a CNT array as a contact layer will improve the thermal transport in vacuum, with a significant improvement over thermal grease designed for this purpose. An important application for this technology is in a thermal switch, where the contact between the two surfaces is not static and conducting epoxies or thermal grease cannot be used.