Carbon nanotubes are long, thin cylinders and large molecules that are unique in their shapes, size, and extraordinary physical and chemical properties. These intriguing structures have aroused enthusiasm in recent years and a great deal of research has also been dedicated to their understandings. Carbon nanotubes are less than 100 nanometres in diameter and can be as thin as 1 or 2 nm. They open an incredible range of applications in materials science, electronics, chemical processing, energy management and many other fields of engineering.