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A “carbon nanotube" is a tube-shaped material, made of carbon, that has a diameter measuring on the nanometre scale. A nanometre is one one-billionth of a meter, or about one ten-thousandth of the thickness of a human hair. The graphite layer appears somewhat like a rolled-up chicken wire with a continuous unbroken hexagonal mesh and carbon molecules at the apexes of the hexagons. |
Carbon nanotubes have many structures, differing in length, thickness, type of helicity, and number of layers. Although they are formed from essentially the same graphite sheet, their electrical characteristics differ depending on these variations, acting either as metals or semiconductors.
Carbon nanotubes typically have a diameter ranging from below 1 nm up to 50 nm. Their length is typically several microns, but recent advancements have made them much longer in the centimetre range.
