Nanotechnology is quickly becoming one of the hottest buzzwords in science. Nanopods, nanoparticles, nanotubes, even the iPod Nano. The last one is a major pet peeve as it has nothing to do with the growing field of nanoscience. The aim of this blog is to try and sort the facts about nanotechnology from the sc ience fiction plotlines, ‘grey-goo’ apocalypse scenarios and wild fantasies of tiny robots. By exploring the latest research findings, cutting through the hype of the newspapers and letting the science speak for itself the true wonder of the ‘nanoworld’ becomes apparent.
So what is ‘Nano’?
Well, if you’re familiar with how much Coke is in a 330 millilitre can compared to a two litre bottle, or how heavy a kilogram of sugar is compared to a 5 gram sugar pack, then nano will be no problem. Like those examples, nano is a prefix used to describe very small fraction of (one billionth) of some quantity. The work of scientists often requires them to switch between the tiny scale of atoms and molecules to the vast sizes of galaxies. Scientists are also somewhat lazy, and it gets very tedious having to say one millionth of a gram or ten billion metres all of thye time. So we use prefixes, like nano, milli and kilo, to be able to avoid such mouthfuls.
The most fundamental quantity in nanoscience is the nanometre (nm), which is one billionth of a metre. To put that in perspective, it takes hundreds of thousands of nanometres to equal the width of one human hair. Also, whilst you read that sentence your fingernails grew by about one nanometre. Now compare those few seconds with often you usually cut your nails (which I would assume is best measured in weeks, assuming you’re not a nervous nail-biter). We’re talking a tiny tiny distance.
The flash applet linked below (from the University of Utah) is an excellent resource for putting this into more context. Use the slider at the bottom to explore the length scales. There is also more info on the prefixes scientists use for different length scales below the applet.
Nanotechnology involves the use and development of devices and materials whose properties originate in structures ranging from 1 nm to a couple of hundred nanometres. On the applet, that’s the size of the measles virus down to the phospholipid, that are both dwarfed even by bacteria.
A good next question would be: Why are scientists so interested in things of this size? After all, atoms and molecules are smaller still. I’ll try to answer that issue in more detail in my next post. However, the simple answer, for now, is that things act differently in the nanoworld. For example, at the sizes we’re used to gold glitters. A clear liquid, when filled with small gold nanoparticles turns blood red. If you use slightly larger particles, the liquid is yellow. This doesn’t sound all that remarkable but scientists are now studying how these gold nanoparticles can be used to treat breast cancer, all because of the science behind this colour change.
I’m getting this ominous sense that I’ll be using the words ‘Size matters’ a great deal in this blog. The truth is, in nanotechnology it really does. However, here all the excitement is in the small things.