Courtesy Sandia National Courtesy Sandia National Laboratories, Laboratories,

SUMMiTTM Technologies, SUMMiTTM Technologies,

www.mems.sandia.govwww.mems.sandia.gov

C2 2.5 NanoscienceWhat can we do with nanoscience?

Imagine a machine that can build a copy of itself…

Now imagine that the machine built a smaller copy of itself…

Now imagine that the smaller machine built a smaller copy of itself…

Now imagine that the smaller machine built a smaller copy of itself… And that one made a smaller copy…And … well you get the picture! How far could we go?Well, we don’t really know.

Technology working with tiny machines may seem like science fiction but this is exactly what nanotechnologists are doing today.At the moment they use simple ‘nanoparticles’ rather than machines but the principle is the same. This slide shows some of the existing projects.Click through to find out more.

Windows that clean Windows that clean themselves?themselves?

Chemistry labs on a piece of Chemistry labs on a piece of card?card?

Sticky tape that doesn’t need Sticky tape that doesn’t need glue?glue?

Socks that don’t smell?Socks that don’t smell?

Titanium oxide nanoparticles Self-cleaning class is covered with a thin titanium dioxide coating. Even on cloudy days, the layer allows ultraviolet light from the Sun to oxidize organic dirt and loosen it from the surface. Raindrops slide down normal glass, leaving dirt streaks and evaporated spots. Self-cleaning glass forces water to spread out evenly in a sheet, washing away dirt loosened by the photocatalytic action.

The smell in smelly socks come from the bacterial breakdown of oils released by your skin. We can’t stop the skin releasing these chemicals but we can stop the bacteria working. Nanoparticles of silver inhibit bacterial growth and so prevent the smell.Silver particles are also used in sticking plasters for cuts. Why?

Testing for some chemicals needs expensive laboratories and can take hours or days to produce a result.We have now developed ways to encapsulate chemical reagents onto cards. These react with the substances that would normally need a whole lab to detect. In this way simple tests can detect viruses or other chemicals in the field and guide doctors in treatment.

The hair on the feet of geckos are so small that they can stick to individual molecules! Nanotechnolog-ists can now coat a tape with sticky hairs of the same size. This means it sticks to anything - and needs no glue.

Human hair

So how big is a nanoparticle? One of the circles opposite is a grain of silver added to (non) smelly socks. Compare this to a human hair. Can you spot the silver grain?

Human hair

This is the correct size!