Fullerenes are known as football-shaped molecules. They are a new material discovered in 1985 by scientists who were awarded the Nobel Prize as a result. A fullerene is made up of 60 carbon atoms linked in such a way as to create a hollow sphere of 0.7 nm in diameter.

In carbon nanotubes, carbon atoms are joined together in a tube-like structure, hollow like fullerenes, with a diameter of from one to several dozen nanometers.

Carbon atoms can also combine to form nanosheets and nanobelts, which are membrane-like structures a few nanometers in thickness.