The Prince of Wales has warned of the possible risks of nanotechnology and called for the cutting edge science to be used "wisely and appropriately".
Charles does acknowledge nanotechnology's possible benefits
In the Independent on Sunday he quotes a retired university professor saying it would be "surprising" if it did not "offer similar upsets" to thalidomide.
Nanotechnology involves the manipulation of materials one-millionth the size of a pinhead.
Prince Charles' concerns about nanotechnology sparked a row last year.
Although his comments have been broadly welcomed by scientists, many feel his reference to thalidomide was "inappropriate and irrelevant".
In the paper he writes: "My first gentle attempt to draw the subject to wider attention resulted in 'Prince fears grey goo nightmare' headlines."
He says he never used the expression "grey goo", adding: "I do not believe that self-replicating robots, smaller than viruses, will one day multiply uncontrollably and devour our planet.
"Such beliefs should be left where they belong, in the realms of science fiction."
The Prince acknowledges nanotechnology is a "triumph of human ingenuity".
"Some of the work may have fundamental benefits to society, such as enabling the construction of much cheaper fuel-cells, or new ways of combating ill-health," he says.
But he adds: "How are we going to ensure that proper attention is given to the risks that may... ensue?
"Discovering the secrets of the Universe is one thing; ensuring that those secrets are used wisely and appropriately is quite another.
"What exactly are the risks attached to each of the techniques under discussion, who will bear them, and who will be liable if and when real life fails to follow the rose-tinted script?"
He expressed concern that only an estimated 5% of the EU's nanotechnology research budget is being spent on "examining the environmental, social and ethical dimension".
"That certainly doesn't inspire confidence," he writes.
Professor Ken Donaldson, professor of respiratory toxicology at the University of Edinburgh, welcomed the Prince's intervention.
He said: "I agree that more research needs to be done and that risk assessment must keep pace with commercial development."
The Royal Society, with which the Royal Academy of Engineering is conducting a study on nanotechnology, also welcomed the article but criticised the thalidomide reference.
It is difficult to make a direct comparison with thalidomide as nanotechnology is not a new drug
The tone of the Prince's article was not panic-inducing but sane and sensible, he added.
"However, there is no direct parallel with the thalidomide disaster," he said.
Executive secretary Stephen Cox said: "The Prince cites one piece of evidence that warns of the possible risks that can be associated with new technologies and the need to address public concerns and interests.
"It is difficult to make a direct comparison with thalidomide as nanotechnology is not a new drug, but rather a set of tools and methods for working with materials at the scale of millionths of a millimetre."