Carbon Nanotube

Carbon nanotubes are miniscule cylinders of pure carbon. They form a fourth variety of carbon after diamonds, graphite and fullerenes. Their diameter is of the order of a nanometre, that is to say a billionth of a meter and their length is in the order of a few dozen, or hundreds, micrometers (a micrometer is the equivalent of a millionth of a metre). They present themselves in the form of a black powder. They are elastic, hollow, twice as light as aluminium, have a resistance to pressure a hundred times greater than steel, and their electrical conductivity is superior to that of copper.