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Last Updated: Wednesday, 28 July, 2004, 23:16 GMT 00:16 UK
Myths and realities of nano futures
By Jo Twist
BBC News Online science and technology staff

Ever since John Dalton convinced the world of the existence of atoms in 1803, scientists have wanted to do things with them.

Micro-submarine in an artery, Science Library image
Machines in the blood: Still science fiction
Nanotechnology takes that ability on to a new plane and opens up all kinds of futuristic imaginings.

Essentially, nanotech is manipulation at the molecular scale - distances that may cover just a few millionths of a millimetre.

But its potential is not just about being able to miniaturise things. Indeed, scientists and engineers recognise that there are fundamental limits to pure miniaturisation.

Working at a scale a million times smaller than a pinhead allows researchers to "tune" material properties, making them behave in different ways to normal, large-scale solids.

This behaviour can be exploited in quite ground-breaking ways.

Geckos do it

Nature has been doing nanotechnology for a long time, and it has become expert in it. Consider the super-fine hairs on a gecko's feet which allow it to stick to walls and even hang upside down on a glass sheet.

How nanotechnology is building the future from the bottom up

Learning from nature, nanotechnology promises humans ways of making systems that are smaller, lighter, stronger, more efficient, but cheaper to produce.

"Nanotechnology is not a technology in its own right," explained Professor Mark Welland, head of the University of Cambridge Nanoscale Science Laboratory.

"It is an enabling technology, so it will appear in many different products.

"It is already appearing in flash memory, computer chips, and it will increasingly be an enabling technology in other products like coatings, new types of sensors, especially in the medical area."

It is expected to transform the performance of materials, like polymers, electronics, paints, batteries, sensors, fuel cells, solar cells, coatings, computers and display systems.

In five years' time, batteries that only last three days will be laughable, said Professor Welland. Similarly, in 10 years' time, the way medical testing is done now will be considered crude.

To say that in five years, an iPod will have 10 times its current storage capacity will be conservative, he said.

In the not-so-distant future, a terabit of data - equivalent to 10 hours of fine quality uncompressed video - will be stored on an area the size of a postage stamp.

Clearly, the devices themselves will not be nano-sized. But nanotechnology will play its part in shrinking components, and making them work together a lot more efficiently.

Although nano-devices can be built atom by atom, it is not realistic as a manufacturing option because it is slow and expensive, thinks Professor John Ryan, head of the Bionanotechnology Centre at Oxford University.

"One of the major scientific challenges in the years ahead is to understand the fundamental biological principles and apply them to produce new types of nanotechnology," he said.

"Armed with these design rules it may then be possible to make new types of nano-device using materials that are more robust than bio-materials."

Future fears

Proponents say misconceptions and misrepresentation of nanotechnology's potential have fuelled many dystopian scenarios. Some are frightening, others are impossible.

The Royal Society and the Royal Academy of Engineering has looked at current and future developments in nanotechnology and has reported on whether it will require new controls.

It is hoped that the report grounds some unrealistic scenarios, while recognising that real concerns need to be addressed with regulation.

"The one fantastical idea that has dogged nanotechnology is the self-replicating machine, the 'grey goo', scenario," said Professor Welland.

"That is simply too far off. I think anyone who is worrying about self-replicating machines should not be looking at nanotechnology for that.

"The complexity of designing a molecular machine is bad enough, but if you try to imbue that with self-replication, you could not even put a toe in the water to design it."

SOME SHORT-TERM NANO USES
Carbon nanotubes (Image courtesy of Institute of Nanotechnology)
Medical diagnostic tools and sensors
Solar energy collection (photovoltaics)
Direct hydrogen production
Flexible display technologies and e-paper
Composites containing nanotubes
Glues, paints and lubricants
New forms of computer memory
Printable electronic circuits
Various optical components
Source: Inst of Nanotechnology
The scenario sees swarms of self-replicating robots, smaller than viruses, multiplying uncontrollably and devouring Earth.

Eric Drexler, who many consider to be a "father of nanotechnology", has distanced himself from the idea, saying such self-replicating nanomachines are unlikely to be widespread.

Similarly, fears over "green goo", the concern that self-replicating, nano-sized biological particles will move into human bodies and do unpredictable things, is scaremongering, thinks Professor Welland.

Professor Ryan agrees: "These science fiction scenarios have not only diverted attention away from the real advantages of nanotechnology, but also from issues that do raise concern."

Inhaled nanoparticles found in the bloodstream which have dispersed throughout the brain is a concern, he says. Whether this poses a health risk is not known.

"If you look around at the moment in a big city, a significant proportion of material that you breathe in is already particulates - and a proportion of that is nano-sized, like diesel emissions," said Professor Welland.

Range of impacts

Nano-materials exploit unusual electrical, optical and other properties because of the very precise way in which their atoms are arranged.

This means fabrics could change colour electronically. Exposing an army uniform to ultra-violet light could activate changes without undressing.

But it is in medicine that nanotechnology offers the most remarkable advances, according to Professor Ryan.

"Nanomedicine will provide earlier and better diagnostics and treatment will combine earlier and more precisely targeted drug delivery," he said. The possibility of individualised therapy is also on the horizon.

Nanotechnology in the form of flexible films containing miniaturised electrodes is expected to improve the performance of retinal, cochlear and neural implants.

And it could lead to the miniaturisation of medical diagnostic and sensing tools, said Professor Ryan, which could drive down costs of such kits for developing countries.

In this respect, nanotechnology could enable developing nations to leapfrog older technologies, in the way that copper wire and optical fibre telephony were superseded by mobile phones.

Material changes

Industrial giants like GE are heavily involved in developing nanotechnology.

"We think that the biggest breakthroughs in nanotechnology are going to be in the new materials that are developed," said Troy Kirkpatrick at GE Global Research.

These include corrosion-resistant coatings to make hydro-electric turbines more efficient in heavily-silted waters, and nano-membrane water filters to make for faster filtration.

SOME LONGER-TERM NANO USES
Miniaturised data storage systems with capacities comparable to whole libraries' stocks
PCs with the power of today's computer centres
Chips that contain movies with more than 1,000 hours of playing time
Replacements for human tissues and organs
Cheap hydrogen storage possibilities for a regenerative energy economy
Lightweight plastic windows with hard transparent protective layers
Source: Inst of Nanotechnology
GE is also studying the properties of nano-ceramics, which can offer extreme strength, while still being lightweight.

Because of the molecular structure of such materials, nano-ceramic coatings on aircraft could make them 10% more efficient, so less energy is used, producing fewer emissions.

GE Global Research is also looking to the electronics industry.

"If you look at the chip makers of the world, the challenge they have is not to figure out how to make them faster.

"The problem is they run so fast, the chips generate too much heat and melt. They need better materials for heat management," said Mr Kirkpatrick.

Using materials which exploit properties of nanoparticles, GE has developed chip adhesives that can transfer heat out of the processor system more efficiently.

"It is a start, and it is to show nanotechnology is finding its way into production and is changing the way we are doing science," said Mr Kirkpatrick.

Uncertainties and worries

Whatever nanotechnology does for the future, it will be an evolutionary process.

One certainty is that there remains a plethora of uncertainties in the emerging field of nanotechnology.

"Medical sensing is very attractive to everybody, but there could be a downside," explained Professor Welland.

"If medical sensors become ubiquitous, our physical state could be monitored 24 hours a day, and if someone hacked into that data, there could be concerns."

Which is indeed why regulation has to be addressed, but must not stifle nanotechnology's potential.

"One of the important things for me is that it ultimately means the most efficient use of materials and processes, which means it does not have to benefit just the G8 nations," argued Professor Welland.

"These sorts of materials, if they are able to do their job using less energy, should be available to everybody."

SOME POTENTIAL USES OF NANOTECHNOLOGIES
Nanotechnology in our lives
1 - Organic Light Emitting Diodes (OLEDs) for displays
2 - Photovoltaic film that converts light into electricity
3 - Scratch-proof coated windows that clean themselves with UV
4 - Fabrics coated to resist stains and control temperature
5 - Intelligent clothing measures pulse and respiration
6 - Bucky-tubeframe is light but very strong
7 - Hipjoint made from biocompatible materials
8 - Nano-particle paint to prevent corrosion
9 - Thermo-chromic glass to regulate light
10 - Magnetic layers for compact data memory
11 - Carbon nanotube fuel cells to power electronics and vehicles
12 - Nano-engineered cochlear implant




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