Will the nanobots turn us into goo?

Nick Morrison tries to get to grips with nanotechnology.

WE'VE been talking for nearly an hour and my head is starting to swim. I have been trying to understand, really I have, but I fear the gormless expression on my face is a bit of a giveaway. Richard Carter has tried flipcharts and computer slides, but it might as well have been in Oybukh*, and I fear he is starting to get frustrated, although he is far too polite to show it.

Then, all of a sudden, a light goes on, and what previously seemed so far above my head it was in orbit, now seems perfectly plain. I think it was the rope bridge what did it. Of course, writing this article is the first real test. If, when you're finished reading, you don't understand it, then I probably didn't either. But if it all seems fairly straightforward and you're wondering what the fuss is about, then feel free to relocate your contempt in a rather intimate manner. I sweated for this, I'll have you know.

The 'it' in question is nanotechnology, the latest thing, the scientific plat du jour. Just to show how 'in' it is, it forms the basis of the new book, Prey, by Michael Crichton, who forecast genetically modified germs in The Andromeda Strain, and taking DNA out of amber in Jurassic Park. Prey tells how a swarm of microscopic robots escape from a laboratory, breed with awesome speed, and devour everything in their path, turning us into copies of themselves, a mass of grey goo.

"It is a great way of helping the public visualise what nanotechnology could be, but it is also slanted. It is a worst-case scenario," Richard says. "You could say that about any technology: it is the application and the people using that technology, not the technology itself." Phew, we're OK then. Although it might be worth pointing out that this scenario has been given a name by scientists: the grey goo problem.

Richard is the business development manager at Newcastle University's Institute for Nanoscale Science and Technology. In other words, he's not a boffin and isn't going to blind me with science, but does know about nanotechnology and is used to explaining it to non-experts, so he should be up to the challenge of explaining it to me.

And it isn't just a theoretical exercise. Nanotechnology is already improving the effectiveness of sun creams, may make hip replacements longer lasting and could see tiny machines implanted in our bloodstreams to keep us healthy. Not to mention these man-eating robots.

Nano, Richard tells me, comes from the Greek, meaning dwarf, and just as centi, as in metre, means a hundredth, so nano means a billionth. A nanometre - you're ahead of me here - is a billionth of a metre, or a millionth of a millimetre. "It's bloody small, when you look at it, really," says Richard, which seems fair enough. Just to give you an idea of the scale, a single blood cell is about 50,000 nanometres big. Nanotechnology itself is concerned with things between one and 100 nanometres in size.

Nanoparticles, crystal structures usually in the shape of a sphere, are not new: they existed long before we knew they were there and occur naturally. When you light a barbecue, it gives off carbon nanotubes and the pigments used in Ming vases are nanoparticles.

But in 1981, IBM developed a special microscope which was able to show individual atoms and molecules, and it was after that that scientists realised these nanoparticles existed.

The reason it is taking off now is the result of two factors. Firstly, the continuing drive to miniaturise things, seen most obviously in the computer industry, where pentium chips are getting smaller and smaller. Secondly, there is the ability to see these tiny particles. Combine the two, and scientists have got new tools to play with things they've just discovered. Bingo - nanotechnology is born.

And it has already been put to good use. For example, scientists have added nanoparticles into tubes of sun cream. The result is a cream which is more efficient at absorbing UV rays and is longer lasting.

The reason nanoparticles are so useful is that their size and shape - think very tiny footballs - means they have a lot of surface area for their volume, making them very good at absorbing and being absorbed, ideal properties for cosmetics. It's no wonder that L'Oreal is one of the biggest investors in nanoparticles.

Another use is in adding nanotubes to plastic, making it harder than steel. This proves useful in car body parts, which are not only tougher, but are also lighter, and so make cars cheaper to produce and more economical to run. As a result, General Motors is replacing its steel compounds with these modified plastics.

And it's the reason why this is the case that the rope bridge - remember that? - comes into play. One of Richard's many analogies, he says that if you imagine that even the most solid of objects are composed of atoms which have a fair amount of space between them, then the nanoparticles are filling in the gaps between these atoms. Because nanoparticles are small, lots of them can fit in these gaps, making the whole thing more solid.

"If you have ropes missing in a rope bridge, then it is weaker, but if there are more ropes there, the harder and stronger it will be," he says. "You are changing the structure of that material. It's like if you've put too much liquid into a curry and you then add cornflower to thicken it." Nanoparticles = cornflower, what could be simpler?

Not to be outdone, the Japanese are looking at a number of potentially startling uses of nanotechnology. In one, tiny patches could be attached to your skin, taking samples of DNA, which allows you to go through coded doors, for example, programmed only to let someone with approved DNA through.

The Japanese are also looking at the possibility of attaching computers to tiny organisms which swim in the blood and can diagnose what's wrong with you.

"The benefits of that are potentially massive, but that is very, very far off, and personally I don't think it is going to go anywhere," says Richard. "But it will significantly build up our body of knowledge, and the more understanding we have, the better we can diagnose conditions and diseases."

And there are lots of other uses, either now or in the future. Artificial hips can be made smoother with a coating of nanoparticles, so they last longer; sensors to detect the presence of chemicals given off shortly before a heart attack can warn of impending danger; computer chips can store much more information than at present; nanoparticles can deliver a more accurate dosage of a drug to a specific area, making treatment more effective - if the list were in nanometres, it would be, oh, very long indeed.

Newcastle University has one of the few nanotech centres in the country, and one of the areas it is looking at is changing the structure of human cells so new tissue of any type can be grown from someone's DNA cells, meaning the tissue will be perfectly matched for them, since it comes from their body in the first place, and won't be rejected.

Where Crichton's vision comes into it is in molecular manufacturing, the possibility of creating tiny little machines, nanobots, which can, in turn, make more sophisticated tiny machines, which can, in turn... you get the picture.

The idea, which is the principle running through nanotechnology is of building things up from the very smallest and most raw ingredients. It's a more efficient use of resources and results in less waste than having to use the materials previously at our disposal. You just have to hope these machines know when to stop.

"In terms of what could happen, it is absolutely unlimited, and that is what Crichton has picked up on," says Richard. "From the simple premise of molecular manufacturing he was able to devise these man-eating nanobots, because in theory, yes you could. It is the application that is lethal, not the technology itself."

So, eventually, in their thirst to create more little machines, these nanobots could turn on us and reduce us all to a mass of grey goo, but that's a way off yet.

*Oybukh: a Crimean language with 82 consonants and three vowels, once used by around 50,000 people, but now with no living speakers. So you have learned something, after all.