Internal zoom in a carbon nanotube.

From a 1 to 5 nanometers section for a few micrometers length, carbon nanotubes are a cylindrical crystal structure of carbon. Discovered by SumioIjima in 1991 after the discovery of fullerenes in 1985 by Harold Kroto, Robert Curl and Richard Smalley (1996 Nobel prize in Chemistry).

Mono-partition or multi-partitions, they have both an excellent rigidity (comparable to that of steel), while being extremely mild. From an electrical and optical point of view, the single-walled nanotubes have the quite outstanding peculiarity that they can be either metallic or semiconductor depending on their geometry.