Smart materials behave differently depending on conditions. (eg. temperature). A good example is nitinol - a shape memory alloy. Its a metal alloy but when ts cool you can bend it like rubber. And when you heat it, it goes back to the remembered shape.
Its really handy for glass frames. If you accidently bend them, you can just pop them into a bowl of hot water and they'll jump back into the shape. Nitinol is also used for dental braces. In the mouth it warms and tries to go back to its remembered shape, and so it gently pulles the teeth with it.
New materials 2
Really tiny particles, 1-100 nanometres across, are called nanoparticles. Nanoparticles contain roughly a few hundred atoms. Nanoparticles include fullerenes. These are molecules of carbon, shaped like hollow balls or closed tubes. They are arranged in hexagonal rings. A nanaoparticle has very different properties from the 'bulk' chemical that its made from.
Using nanoparticles is called Nanoscience. Many new uses for them are being developed:
- They have a very large surface area to volume ratio, so they could help make new industrial catalysts
- They can be used to make stronger, lighter materials
- You can use them to make lubricant coatings for artificial joints and gears.
- Nanotubes can conduct electricity, so they can be used in tiny electric circuits.