LONG TERM POSSIBILITIES

You may have read in the popular press of an imminent future, with tiny submarines patrolling our bodies, stitching up damaged tissue, zapping an occasional cancer cell or invading virus or switching off an errant gene; nanorobots weaving extensions to our brains to enhance our intelligence; desktop machines that can make you a diamond ring; a table that will transform into a chair at the flick of a remote control; and even immortality. These examples represent the sensationalism and distortion of the popular press but are based on some seriously made predictions of possible futures. Still, it's just so much science fiction, surely?

Not necessarily. While some of the wilder visions of nanotech-enabled futures are extremely speculative, they stem largely from quite straightforward ideas founded in solid science, and generally referred to as molecular nanotechnology (MNT). However, it is important to distinguish between MNT, the potential benefits of which are long term, and the mainstream applications of nanotechnology, which are of more interest to investors in the near and medium terms. There is big difference between molecular assemblers and the use of nanoclay particles as additives in the plastics industry. Failure to distinguish between what is available now and what is theoretically possible at some point in the future has been the cause of many of the misconceptions about nanotechnology. It should be noted that MNT has attracted little interest from the business community, owing to its long timescales, and has not, rightly or wrongly, been accepted by the scientific community at large.

The core idea of MNT is that of making robotic machines, called assemblers, on a molecular scale, that are capable of constructing materials an atom or a molecule at a time by precisely placing reactive groups (this is called positional assembly). This could lead to the creation of new substances not found in nature and which cannot be synthesized by existing methods such as solution chemistry. Molecular modeling has been used to support the potential existence and stability of such materials.