A nanotube material conducts heat in just one direction technologyreview.com

That means heat can spread to any other component that is also in thermal contact with the metal.
Enter Shingi Yamaguchi at the University of Tokyo in Japan and a group of colleagues, who have created a material out of carefully aligned carbon nanotubes that conducts heat in just this way.
Yamaguchi and co say the new material conducts heat in the direction of nanotube alignment with a thermal conductance of 43 W m-1 K-1.
Each jump that the heat has to make from one nanotube to the next reduces the thermal conductance.
“This suggests that the [thermal conductance in the direction of nanotube alignment] can be even greater with longer constituent carbon nanotubes,” they say.