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Nanotechnology in the media


What is nanotechnology?

Nanotechnology involves the study and use of extremely small substances, often called nanoparticles.

Nanoparticles are very small, less than 100 nm across, but just how small is that?

The word ‘nano’ comes from the Greek word which means ‘dwarf’.

A nanometre (nm) is 0.000 000 001 metre (or 10-9 m). That’s one millionth of a millimetre.


How small is nanotechnology?


When did nanotechnology start?

Nanotechnology is not a new idea. Nanoparticles have in fact been used by people for thousands of years.

The Egyptians used ink containing nanoparticles of black pigment.

Nanoparticles of gold and silver have also been used since the 10th century to colour ceramics and stained glass.

Nanoparticles of lead sulfide were used by the Romans to dye their hair black.


Are there nanoparticles in nature?

Natural nanoparticles also exist. For example:

Nanotechnology scientists try to copy natural nanoparticles to make new materials that are useful.

Insects and lizards are able to stick to walls because of the nanostructures on their feet.

Butterflies’ wings contain shiny reflective nanocrystals.

Spiders’ webs are made of super-strong nanofibres.

Chloroplasts in plant cells are nanofactories that harness the Sun’s energy to make glucose.


When did modern nanotechnology start?

The idea of nanotechnology was suggested in 1959 by Richard Feynman, an American physicist.

The prize was claimed just a year later by Bill McLellan, a scientist working in California.

He offered a $1000 prize for the first working motor less than 1/64th of an inch across (smaller than a pinhead).

Scientists have since made structures smaller and smaller. This work is now called nanotechnology, a term first used in 1974 by Norio Taniguchi, a materials scientist in Japan.


How has nanotechnology developed?

As scientists have steadily made things smaller, they have needed new pieces of equipment to help them.

In 1989, an STM was used to move 35 xenon atoms onto a tiny piece of nickel.

In 1981, the scanning tunnelling microscope (STM) was invented and allowed scientists to see the nano-world.

Using an STM, it is possible to see individual atoms and even move them around.

The atoms spelled the name of the company that the scientists worked for. What was it called?


Properties of nanoparticles – movement

Forces affect nanoparticles more because of their small size.

Imagine being the size of a nanoparticle and going for a swim!

Swimming would feel like being in treacle because it is hard for such tiny particles to move through water molecules.

Nanoparticles are so small that gravity has much less effect on them. So if you tried to jump into the pool, you might not go in the direction expected.

Walking to the pool would be difficult because air particles would bump into you and knock you all over the place.


Properties of nanoparticles – appearance

Nanoparticles also interact differently with light.

Normally, gold metal appears gold in colour. However, nanoparticles of gold in solution appear red and blue in colour.

Different-sized nanoparticles of gold give different coloured solutions.

Smaller nanoparticles appear red in solution, while slightly larger nanoparticles appearblue.


Properties of nanoparticles – surface area

Nanoparticles have a much bigger surface area to volume ratio than larger particles.

Nanoparticles have more atoms or molecules nearer the surface than larger particles.

low surface area to volume ratio

high surface area to volume ratio

This is very useful for substances such as catalysts.

In reactions, nanoparticles are able to react more quickly. This is because more atoms in a nanoparticle can be in contact with the reactant, than in a larger particle.


Nanotechnology – true or false?


How are nanoparticles made?


Using nanoparticles – health

Nanoparticles are already used in various ways.

Plasters and bandages can contain nanocrystals of silver, because it is toxic to bacteria. Silver can even be woven into athletes' socks to kill the bacteria that makes socks smell.

Sunscreen contains nanoparticles of zinc oxide and titanium oxide, which absorb and reflect harmful UV rays from the Sun.

These particles are so small that they are invisible on the skin. Before nanoparticles, the oxide particles were big enough to be seen, so the sunscreen looked white on skin.


Using nanoparticles – cleaning

Nanoparticles can also help to keep things clean. Could dirty football shirts be a thing of the past?

Fabrics have been developed with nano-coatings, which repel liquid and resist stains.

Windows that are self-cleaning have been developed by British scientists. How could self-cleaning windows work?

Spillages on treated fabrics will not soak into the fabric, but form beads of liquid, which can simply be wiped away.


Using nanoparticles – glass


Methods of making nanoparticles


What are fullerenes?

The element carbon can exist in different structural forms, which are known as allotropes.

Carbon can also exist in other forms, collectively called fullerenes.

Diamond and graphite are the two most common allotropes of carbon.

The first of these, buckminsterfullerene, was discovered by accident, in 1985, and its discovery opened up a whole new area of chemistry.


How was buckminsterfullerene discovered?


What are the physical properties of C60?

It is a black solid at room temperature which does not conduct electricity.

The physical properties of buckminsterfullerene are:

It is insoluble in water but dissolves in petrol to form a deep red solution.

Its molecules are strong and hard, but elastic, like a football. They can be squashed to 70% of their normal size, but bounce back.


What are the chemical properties of C60?

The chemical properties of buckminsterfullerene include:

The molecules can be used as cages to trap atoms and smaller molecules inside them.

The molecules can be joined together to make bigger fullerene structures.

The surface of C60 molecules can be coated with other atoms. For example, coating with hydrogen makes a smooth substance that is even more slippery than Teflon.


More about fullerenes

C60 molecules are also known as ‘buckyballs’.

C70 molecules, which are shaped like a rugby ball.

Buckybabies, with less than sixty carbon atoms.

Fuzzyballs, with a coating of hydrogen atoms.

Giant fullerenes, with many more than sixty carbon atoms.

Since the discovery of this first fullerene, other types of fullerenes that have been made include:


What are the uses of fullerenes?

Non-stick slippery coatings for machinery, which act like miniature ball bearings.

Some of the uses of fullerenes that scientists are currently working on include:

Cages to hold drug molecules that can be delivered directly into the body.

Molecular sieves, which traps large particles like viruses while allowing smaller, healthy particles to pass through.

Chemical sponges to soak up toxic substances in the body.


What are nanotubes?

Nanotubes are another form of fullerene. They are tubes of carbon hexagons, like sheets of graphite rolled into cylinders.

Nanotubes have many useful properties, including:

very high tensile strength unique electrical properties good heat conductance.

Multi-walled nanotubes exist. In these, several tubes can rotate and slide within in each other, almost without friction.

Metal atoms can be attached to the outer surface of the tubes.

With these properties, what might nanotubes be used for?


What are the uses of nanotubes?

The properties of nanotubes make them useful in many ways.

Thinner, lighter TV screens.

Strong, light waterproof fabrics.

Smaller, thinner optical fibres.

Smaller, lighter electrical circuits.

Stronger building materials.

Some examples include:


Missing words on fullerenes


Future uses of nanoparticles

How might nanotechnology be useful in the future?


Future uses of nanoparticles – medicine

There are many possible medical uses of nanotechnology.

Nano-capsules of drugs that will target cancer cells only.

Nano-electronic implants in the retinas of blind people, which communicate with cells, making it possible for them to see.

Nano-coatings on hip and joint replacements to prevent rejection.

Nano-scaffolds will be able to support the growth of new skin and body tissue.

Nano-sensors inside clothes, or even inside our bodies, that will be able to run health checks or deliver medicine.


More future uses of nanoparticles

Other future uses of nanotechnology include:

Nano-scale microchips and wires for smaller electrical devices.

Nano-scale solar cells to trap solar energy, mimicking photosynthesis.

Nano-size containers to store hydrogen, being used as a fuel.

Paints and glues containing nanoparticles will be lighter, stronger and need less solvents.

Composite materials made from nanostructures, which are stronger, harder and lighter.


Using nanoparticles: current or future?


Is nanotechnology safe?

As nanotechnology becomes more commonplace, how careful do we need to be?

What problems might be associated with nanotechnology?

Do you think this is a realistic possibility?

In 1986, a researcher called Eric Drexler made a prediction about nanoparticles in the future.

He suggested that because nanoparticles can build themselves into molecules by self-assembly, self-replicating nano-robots will consume the atoms of the world as they replicate, eventually turning everything into a “grey goo”.


People’s opinions on nanotechnology


Nanotechnology – harmful or beneficial?


Is nanotechnology worth developing?


Glossary (1/2)allotrope – A structurally different form of an element,

which has different physical properties.

bottom-up – A method of building up nanoparticles one atom at a time.

buckminsterfullerene – The hollow, spherical fullerene molecule made up of 60 carbons atoms.

fullerenes – The family of carbon allotropes, in which the atoms are joined together to make hollow spheres or tubes.

nanometre – A measurement equal to 0.000 000 001

metres.


Glossary (2/2)nanoparticle – A particle which measures less than 100

nanometres in size.

nanotechnology – The study of nanoparticles and their uses.

nanotubes – Fullerene molecules made of carbon atoms arranged into hollow cylinders.

self-assembly – A method of building nanoparticles in which atoms and molecules arrange themselves.

top-down – A method of making nanoparticles by starting with larger particles and shaping them into smaller pieces.


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