Nanotechnology refers to the construction and use of atomic machines—functioning consortia of atoms that are less than about 1,000 nanometers in size. A nanometer is one billionth of a meter. The technology is relevant to computer science as it could potentially be used to construct molecular computers, which could be smaller than the size of a bacterial cell and capable of performance exceeding technology currently in use.

Molecular machines are in the early developmental stages. Several reports have described the physical rearrangement of atoms into a desired configuration, such as the use of a scanning tunneling microscope by IBM (International Business Machine) researcher John Foster to push xenon atoms around to spell "IBM." Other reports have described the atomic assembly of crude interlocking gears. And, in 1999, a molecular electronic research team successfully constructed a "molecular wire" circuit based on a polyphenylene polymer and a functional molecular switch...