Alert over the march of the 'grey goo' in nanotechnology Frankenfoods

Some critics have talked of the threat of the creation of a "grey goo" of tiny particles with hidden harmful properties.

Prince Charles has said it would be "surprising" if the technology did not "offer similar upsets" to thalidomide - the morning sickness drug that caused children to be born with deformed limbs.

Professor Vicki Stone, Professor of Toxicology at Napier University in Edinburgh, is concerned about unforeseen side effects.

"We know very little about the ability of nanoparticles to move around the body, to accumulate or to be excreted, or their potential to cause toxic effects in organs," she said.

However, nanotech advocates have remarkable claims for the technology. For example, foods are in development that are said to stave off the aging process.

On a more trivial level, they suggest it would be possible to create a fizzy drink that changes flavour according to the number of times the can is shaken.