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Nanotechnology is already all around you

You may think the use of nanotechnology may lie somewhere in the future, but you are probably already putting the science to work when you use sunscreen, or any number of other consumer products on the market.

No, nanotechnology does not have anything to do with Apple iPod Nano music player, which has taken the name in a bid to cash in on the technology's growing trendiness.

We are talking something way smaller here. Nanotechnology is the science of manipulating matter in dimensions as small as the atomic level or as single molecules to create a specific behaviour.

The science is based on the principle that at the microscopic level materials behave in very different ways than at the macroscopic. Due to consumer concerns over the safety of the science, companies generally do not hype the fact that they are using the technology for their products.

A new report by Nanoforum found that in general the products claiming to contain nanotechnology do indeed exploit nanoscale effects, primarily interface effects but also a few quantum effects.

Closer to the skin is the incorporation of zinc oxide (ZnO) or titanium dioxide (TiO2) nanoparticles into sunscreen. The metals have long been known to be effective UV absorbers and have been used for decades.

However as large particles, these materials appear as white pastes which limits their aesthetic appeal. By making the particles smaller than the wavelength of light they no longer absorb visible light, and therefore the sunscreen appears transparent, while still absorbing dangerous UV light from the sun.

Both zinc oxide- and titanium dioxide-containing sun lotions are available from different manufacturers, Nanoforum found.

Another approach based on tiny particles can be found in special toothpastes for sensitive teeth. Teeth consist of a hard protective enamel covering the more sensitive softer dentine. The dentine itself is covered with tiny holes of 2-3 microns in diameter called dentin tubuli, which form a connection to the underlying pulp and thus to the nerve itself.

Problems can occur when the gum recedes and the cementum wears down, leading to an increase in tooth sensitivity.

Now toothpastes are being designed containing nanoscopic crystals of hydroxyl apatite, the main ingredient in natural dentin. The hydroxyl apatite acts to seal the dentin tubuli, stopping the pain.

The toothpaste induces a crystallisation of calcium phosphate from saliva using a biocomposite of hydroxyl apatite and protein molecules, forming a protective layer on the teeth. Incredible!

Meanwhile Carter-Wallace has used a nanotech-based approach to create a new type of home pregnancy test. The company made use of the unique optical properties of gold nanoparticles resulting from surface plasmons.

The Carter-Wallace home pregnancy test, called "First Response", uses conventional micrometre-sized latex particles in conjunction with gold nanoparticles (less than 50 nm diameter) to produce a pink colour when exposed to certain hormones produced by pregnant women.

Nanotechnology also appears in the light emitting diode (LED), widely used for displays. White LEDs can be found in flashlights where they have replaced incandescent bulbs because they give a much longer battery lifetime.

White LEDs generate their light in very well defined regions, called quantum wells, which are manufactured with "atomic" precision and with thicknesses of about 10 nm. A similar technology is used in certain laser diodes, where the movement of charge carriers is restricted to semiconducting nanocrystals referred to as quantum dots, primarily used in medical diagnostics and biotech industries for molecular recognition.

Numerous product innovations rely on the incorporation of nanoparticles in an organic matrix, often referred to as nanocomposites. For example ultrafine carbon particles, called carbon black, are widely used as a reinforcing filler material in rubber products such as automobile tyres and as a pigment in printer toners.

Other carbon black uses include skiing wax ("nanowax") and ultra light bicycles for the Tour de France.

At least four different companies worldwide offer tennis rackets reinforced with carbon nanotubes. By making use of a stronger material, the overall weight of the racket can be reduced while the stiffness is maintained or even increased.

Other sporting goods which make use of carbon nanotubes reinforcement include baseball bats from Easton, badminton rackets from Yonex and hockey sticks from Montreal Hockey.

Tennis balls from InMat and golf balls from NanoDynamics and Nano-S Inc. are also on the market, claiming to have nanotechnologically improved properties.

While Nanoforum's scientists say the claims about the increase to lifespan for tennis balls is credible, they are sceptical about the golf balls.

"However, the golf ball claims to fly "straighter" and to roll better due to a hydrophobic surface are a little more doubtful," they note.

Other consumer products include a self-cleaning sheet glass based on titanium dioxide particles. The self-cleaning layer of the Pilkington Activ activates itself after being exposed to UV light, and results in the breakdown of organic compounds.

The same photocatalytic principle has been used to produce self-cleaning clay roof-tiles by Erlus. All this goes to show that nanotechnology is here to stay.

And there is more. As I've said before in this space, let's make sure the regulation is there to deal with the new science, before we are caught unawares by some unexpected side effect.

The full report can be found on www.nanoforum.org.

Ahmed ElAmin is a former Royal Gazette business reporter who writes on technology. E-mail him at elamin.ahmedgmail.com