A thermally and electrically conductive structure comprises a carbon nanotube (110) having an outer surface (111) and a carbon coating (120) covering at least a portion of the outer surface of the carbon nanotube. The carbon coating may be applied to the carbon nanotube by providing a nitrile-containing polymer, coating the carbon nanotube with the nitrile-containing polymer, and pyrolyzing the nitrile-containing polymer in order to form the carbon coating on the carbon nanotube. The carbon nanotube may further be coated with a low contact resistance layer (130) exterior to the carbon coating and a metal layer (140) exterior to the low contact resistance layer.