Silicon is the most investigated material, and because of our thorough knowledge, silicon is not only the basis of electronics, but also of micromechanics. Carbon has been mainly studied in the context of organic chemistry. But in the last few years the various modifications of pure carbon have attracted the attention of materials scientists. In the form of diamond, carbon is the hardest material known, and diamond also has the highest thermal conductivity. Graphite, on the other hand, is a good electrical conductor.
Carbon nanotubes are very thin and long tubes.
Their diameter is only one or a few nanometers, which means that they are not thicker than typical molecules, and their length can be several micrometers and even millimeters. In electronics, these nanotubes are discussed as quantum wires and quantum dots. They can be used as components of nanostructured field effect transistors and single electron transistors. Their mechanical strength enables applications in nanocomposite materials and, because of the large surface area per weight, nanotubes are good candidates for all sorts of gas adsorption, including hydrogen storage for sustainable energy supplies. From X-ray investigations of graphite we know that the honeycomb lattice expands if the graphitic sheets are electrically charged.