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In search of the very, very small

I spent three days last week in Basel being taken around to see various pieces of research the research outfits around there are doing into nanoscience, courtesy of the European Union of Scientice Journalists' Associations (my affiliation is with the Association of British Science Writers). All very interesting stuff, and difficult to summarize intelligently in a few hundred words, though I made a stab at some of the medical stuff. The thing that most struck me immediately, though, was how different it all was from the image of nanotechnology I'd half-formed from odds and ends I'd read or heard about in the media.

I probably just don't read enough.

The first time I ever heard of nanotechnology, though I'm not sure they used the name, was in a three-part 1988 documentaryTV series called What is Truth?: Seeing is Not Knowing. It was produced by the distinguished science producer and writer Karl Sabbagh, and looked at how we know what we know about things we can't examine directly, such as the contents of memory, the very large (space) and the very small (molecules). Two enduring images stick with me all these years later: a guy riding a bicycle through the CERN particle accelerator to cover the distance to the bit that needed repairs, and their mock-up of what a nanofactory might be like. By then people were already talking about the idea that we could have machines in our homes into which you put ingredients and instructions and out of which you later take whole devices or whatever. The machine was played by a dishwasher and the emerging device by a boom box, and the whole thing looked pretty hokey, but still: molecular manufacturing.

But that's not what the people in Basel were doing at all; at no point in the three days did anyone talk about building consumer devices or the grey goo that belongs in a horror movie. Instead, what kept reappearing was various types of microscopes - atomic force, scanning probe, even a synchrotron. From those, we saw a lot of highly detailed images of really tiny things, such as collagen fibers waiting to cause havoc in the human bloodstream and three-dimensional images of rat brains.

I think everyone's favourite presentation was that of Marc Creus, from the Institut de Microtechnique in Neuchâtel, who said cheerfully he was there to talk about a hole. Actually, a nanopore, 25 nanometers in diameter. The idea is to build on a technique created by the engineer Wallace H. Coulter, who created a simple device – essentially, a box with two chambers divided by a membrane (in its first prototype, the cellophane off a pack of cigarettes) with a small hole in it (originally, melted with the heated point of a sewing needle) – to count microscopic particles suspended in a fluid. A solution passes through the hole simultaneously with an electric current; when a particle goes through, the current shows a change proportional to the size of the particle. The particle, in other words, briefly partially blocks the hole.

The way Creus told it, Coulter had been experimenting with paint, but one night left the paint open. The next night, finding it had dried out, he looked around for another liquid – and wound up using blood. The Coulter Principle, as it's now known, is used all over the world for analyzing blood samples ("complete blood cell" counts). He had trouble getting a patent on it, by the way; the examiner thought it was too simple, and anyway you can't patent a hole. He eventually got his patent in 1953 and became quite wealthy from his device.

Creus is trying to shrink the Coulter Principle with the idea of exploring the nanoscale: nanopores should make it possible to count protein molecules. You could, for example, test for the presence of a particular protein by adding them to a device that already contains its antibodies. The protein bound to the antibody will be a bigger molecule than either on its own.

Even weirder, Urs Staufer, from the same institute, is using nanoscience to explore…Mars. There's something very strange about the notion of using something tiny to study something really large. But the deal is that one of these scanning proble microscopes, specially adapted, will be on the first Mars Scout mission, due to launch in August. A robot arm will go along scooping up samples of…what do you call it when it's Mars? It can't be earth, can it? Anyway, the robot arm pours the sample on a wheel that rotates in front of the microscope, and the images are sent to Tucson and everyone has four hours to decide if they want to look at it more closely and compile the commands to send for the next go-round. The hope is that they'll find ice underneath the surface and will be able to dig down and investigate it.

I suppose all this makes sense. You can't really manufacture anything, at any scale, until you understand how it all works, just as you can't colonize anywhere until you've explored it. If they get down the nanoscale far enough, will they plant a tiny Swiss flag?

Wendy M. Grossman’s Web site has an extensive archive of her books, articles, and music, and an archive of all the earlier columns in this series. Readers are welcome to post here, at net.wars home, at her personal blog, or by email to netwars@skeptic.demon.co.uk (but please turn off HTML).


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