Nanoscience

‘Nano’ means small, right? Sort of. To scientists, ‘nano’ doesn’t just mean small. It means almost unimaginably small. A nanometre (nm) is a billionth of a metre, so when scientists refer to things as nano, they are talking about things a few billionths of a metre in size.

Nanoscience or nanotechnology means the study of chemical and physical changes that happen at the nanoscale. By nanoscale, we mean in the region of 1–100 nm, where properties of substances differ from those at a larger scale. Nanotechnology makes use of these nanoscale properties to develop new materials and devices.

Nature of science

Nanotechnology is often seen as a trendy new science that will change our future. It is new, in the sense that new techniques and instruments are used, and new materials and devices are developed, but it is based on knowledge gained over many years, in many fields of science.

The word ‘nano’ originally meant ‘dwarf’, and it has been around a long time. Sometimes people have used ‘nano’ to label something small. In 1877, a dinosaur only a metre long was named Nanosaurus. Recently we have names such as the iPod nano, a small media player.

Nanotechnology new and old

The idea of nanotechnology started in the 1950s, though the name wasn’t invented until 1974. In a way, though, nanotechnology has been around for centuries. After all, a lot of chemistry is about controlling nanoscale objects – atoms and molecules – and since ancient times, artists have used the special properties of gold and other metal nanoparticles to colour glass, but without knowing about ‘nanoparticles’.

What makes nanotechnology new is the way that scientists and engineers are learning to see, understand, measure and manipulate matter at the nanoscale.

Early pioneers of nanotechnology saw a world where everybody would have a personal machine that could assemble anything they wanted, atom by atom. No more growing food, no more factories – no more work! Nanoscale, self-replicating robots would keep our bodies healthy and long-lived. The whole structure of society would change.

Many scientists believe that this vision of a future based on nanotechnology will never happen, not only because they think the technology dreamed about is impossible, but because society won’t let it happen. But some changes are already taking place. Instruments have been invented that let us see and manipulate atoms. Nanotechnology products are all around us.

You can already buy sunscreens and skin creams based on nanoparticles, new paints, stain-repellent clothes, and many other things. Nanotechnology is helping us switch from non-renewable fuels to fuelcells and solar power. There are smart materials like new computer screens and self-tinting windows. An iPod makes use of nanotechnology to store and read huge amounts of data.

Nanotechnology is also creating new problems, and causing scientists to think of new ways of doing things. The components of computers are now becoming so small that they have different properties to larger components. This means that the computers of the future need to be reinvented.

The future of nanotechnology

Imagine thousands of tiny man-made bits of silicon injected into your body. They’re only a few billionths of a metre across. They track down cancer cells and kill them with drugs they are carrying. You can see where the nanoparticles are because they give off coloured light. Far fetched? You may think so, but scientists in Wellington are already well on the way to making it real.

All over the world, nanotechnologists are developing materials and devices that have the potential to change our lives. Nanoscale pumps, switches and motors exist, but the tiny, self-replicating machines seen by nanotechnology pioneers are a long way off, if they happen at all. But we know they work. After all, the DNA of living organisms is a successful nanoscale, self-replicating molecular machine that builds up structures molecule by molecule. And life depends on it.

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