Mighty mini

A computer illustration of a medical nanorobot, a microscopic robot whose uses could include targeted delivery of drugs. Picture / Photolibrary

The best things are supposed to come in small packages. In the future, this could be more true than ever. Thanks to nanotechnology - the manipulation of tiny elements - we could enjoy a host of new developments, including furniture that can think, cars that change colour, even mobile phones with breathalysers - no more will we drink and dial.

The official definition of nanotechnology is the design and control of things at a nanoscale (100 nanometres and below). To put this into perspective, 100nm is one thousandth of the width of a human hair, and about 500 times the size of an atom.

By this definition, we've been dealing with nano-sized particles for a long time. Intel's latest microchips have components measuring just 65nm across. Skin cream has used nanoparticles for years, and many polymers - large organic molecules formed by stringing lots of smaller elements together - are made up of nano-sized units.

What makes today's nanotechnology different is our ability to manipulate these tiny components more directly than ever before, along with the ability to drastically change their properties, says Philip Kuekes, a nanotechnology scientist at the Hewlett-Packard Laboratories in California.

Because of their size, nanoparticles can take advantage of quantum physics, where the traditional laws of physics break down.

"Those laws give you a lot more knobs to turn," Kuekes says, and although 100nm is the official threshold, many materials begin to experience quantum-physics effects only at smaller sizes.

"Some things change at 100nm, while other things only change at 3nm or 4nm."

Nanoparticles' diminutive size also means that their surface area relative to their interior is greater than that of larger particles. Because many chemical and other physical reactions happen at the surface of a material, this larger surface area can exaggerate a nanoparticle's properties. Sticky materials may be stickier, for example.

One of the most attractive propositions of nanotechnology is simply the ability to work in minute sizes. California Institute of Technology (Caltech) scientist Richard Feynman recognised this in 1959, when he gave a breakthrough speech on nanotechnology, titled Plenty of Room at the Bottom.

Feynman proposed using a mechanical tool to build a set of smaller tools, which could in turn be used to build even smaller tools. Eventually, scientists would be working on such a small scale that they could bolt atoms together in any configuration, which would theoretically enable them to build any substance from scratch, he postulated.

"Manipulating properties at a nanoscale has only been done for 20 years or so, following the invention of the scanning probe microscope," says Andy Garland, chief executive of the Technology Transfer Centre at the Institute of Nanotechnology at Stirling University.

This class of microscope, discovered in 1982, made it possible to "see" at the atomic level.

Since then, researchers have worked to refine nanotechnology and in 1991 discovered the carbon nanotube (CNT), a cylinder of rolled- up carbon atoms a couple of nanometres across, which is both flexible and hundreds of times stronger than steel.

CNTs can, theoretically, be strung together to create incredibly strong and light structures that could revolutionise the future of architecture. These, along with other molecules such as buckminsterfullerenes - spherical carbon molecules that could be used as nanoscale ball-bearings - are not created by physically placing atoms together but by using chemical self-assembly.

Even though we have not yet created atom-sized robots that can build other robots, the opportunities for chemical and other types of nanotechnology are immense, says Dr Andrew Maynard, chief science adviser for the Project on Emerging Nanotechnologies, based in Washington, DC, which examines the social effects of nanotechnology.

"Nanotechnology will make small but subtle changes in areas that will have profound implications," Maynard says. "People won't realise how important they are until they look back."

For example, using nanotechnology to give lithium ion batteries a much greater capacity and charge could get them into cars, thus affecting how we view automotive energy and the use of oil.

In that sense, Maynard believes that nanotechnology will be as pervasive a development as the industrial revolution, but take place over decades rather than centuries.

Small wonder that governments are interested. The United States Federal Government has invested the equivalent of NZ$10 billion in nanotechnology since the formation of its National Nanotechnology Initiative (NNI) in 2001.

Despite the funding, most developments are enhancing existing products. Nanoparticles already make sun-cream colourless, fuel last longer, and keep socks fresh. But Garland says we will have to wait three to five years to see products that would not previously have been possible, says Andy Garland.

Some nanotechnology will become even more exciting, but some experts advocate caution. Two years ago the Royal Society and the Royal Academy of Engineering recommended that more research be done into the potential health and environmental effects of nanoparticles.

The reinsurance company Swiss Re has also raised concerns about absorption of nanoparticles through the lungs and the skin into the blood and brain.

Nanotechnology will proceed in small steps over the next few years, so don't expect to see clothes that change colour in the stores this Christmas. Perhaps appropriately, given the nature of the technology, some of the developments won't be visible to the consumer at all.

Consumer Products

What's already there?

Nanomaterials are now used for self-cleaning windows, fabrics and anti-graffiti paint. Carbon nanotubes are reportedly used in the Nissan X-Trail car to strengthen its bumper.

What's coming soon?

Materials will gain new properties, including colour-changing abilities. Antibacterial surfaces will become more common (Motorola hopes to build phones with these surfaces in three years).

Stronger, lighter materials could change everything from architecture to transport. The US company LiftPort hopes to launch a "space elevator" by 2018 using a ribbon made of carbon nanotube composites, to ferry satellites 100,000km into space. Hewlett-Packard is working on electronic switches only a few nanometres thick. This could lead to computers with memories thousands of times greater. HP predicts the emergence of "smart objects" with built-in computers, including clothing.

Pipedream or possibility?

Work to build robots at nano level is still rudimentary. If it came to fruition, we might realise Richard Feynman's vision of molecular manufacturing - creating substances by building them out of atoms. In such a scenario, you could take an old car tyre, put it in your nanotech converter, press the button and turn it into a hamburger.

The Body

What's already there?

Researchers at Edinburgh University have moved a tiny droplet of water using light-sensitive molecules, which could lead to applications for "lab on a chip" technologies. At Stanford University, researchers have used heated carbon nanotubes to kill cancer cells.

The US firm EndoBionics has developed a micron-scale microsyringe for injecting drugs into the heart.

What's coming soon?

Companies, including QinetiQ, are developing an antiviral nanomaterial for masks that could protect people against bird flu. Another promising area is targeted medicine delivery, where an infected site would be magnetised so that magnetic nanoparticles would attach only to that tissue.

Pipedream or reality?

Some experts predict the use of nano-sized robots that will travel in the bloodstream, cleaning arteries and administering drugs and repairs.

The environment

What's already there?

Nanotechnology is already used in fuel enhancers. The British transport company Stagecoach uses Oxonica's Environ, a nanotechnology catalyst that helps to reduce emissions and increase fuel efficiency.

What's coming soon?

Nanotechnology could make water purification easier and cheaper, thanks to nano-engineered filters. With even worse water shortages on the horizon, desalination could be an important application within decades.

Batteries could be made more efficient using nanotechnology-based separator plates able to hold more energy than conventional ones and increase power density. Fuel cells could also be made smaller and more efficient.

The Royal Society and the Royal Academy of Engineering has predicted the distribution of power production closer to the point of use, which could have big effects on energy policy. Iron nanoparticles could be used for land remediation, breaking down organic chemicals in the environment and rid it of some pollutants.

But some experts are concerned about releasing nanoparticles into the environment without sufficient research on their broader effects.

Pipedream or possibility?

Smart nanotechnology-based sensors could be placed in the environment to measure a plethora of conditions, reporting on temperature and vibration, and watching for chemical or biological content.

- INDEPENDENT