Nanotechnology

On December 29, 1959, the American physicist Richard Feynman gave a seminal lecture to the American Physical Society entitled “There’s Plenty of Room at the Bottom”. In this he discussed the benefits to society that would accrue if we were able to manipulate matter and manufacture artefacts with precision on a scale of a few atoms across, which corresponds to a dimension of about 1 nanometre. He correctly foresaw, for example, the impact that miniaturization would have on the capabilities of electronic computers; he also predicted the development of the methods that are now used to make integrated circuits and the emergence of techniques for writing extremely fine patterns with beams of electrons. He even mooted the possibilities of making machines at the molecular scale, which would enable us to manipulate chemical and biological molecules. Forty years on from this lecture, technologists working in the field of nanotechnology are starting to realize some of the ideas originally propounded by Feynman, and many others that were not foreseen at that time.
In order to grasp the scale of a nanometre length, consider a human hair. This is typically about 100 micrometres (µm) in diameter. (A micrometre is one millionth of a metre, or 40 millionths of an inch). A typical bacterium is about 100 times smaller than this, or about 1 µm in diameter. A common-cold virus is approximately one tenth of this size, or about 100 nm across. A typical protein unit making up the coating of such a virus is typically 10 nm thick; a distance of 1 nm is equivalent to about 10 atomic diameters, or the size of one of the amino acid groups making up that protein molecule. It can thus be seen that 1 nm is an exceedingly small dimensional tolerance to work to, but a...

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