Nanotechnology – Hype, Hope or Hell?

Duncan Graham-Rowe

March 2004

In the last few years, nanotechnology has risen from relative obscurity to become one of the most hyped and talked about areas of science. And, one of the most controversial. Nanotechnology, we are told, will bring us stronger, lighter and smarter materials, and enable the creation of tiny devices to repair our bodies from the inside out. Seduced by such possibilities, governments and industry are investing millions in this frontier. Some companies, wising up to the opportunities, have even added 'nano' to their names to ensure they get a slice of the action.

But for every voice extolling the virtues of nanotechnology there are others condemning it. Nanotechnology has attracted the criticism of high profile environmentalists, such as Prince Charles. As a result of concerns raised about its safety, organisations, like the Royal Society, are trying to gauge the likely impact of nanotechnology on humanity.

So what's all the fuss about? If you cut through the hype, is nanotechnology really the Pandora's box that some media reports make it out to be, or will it prove to be a useful science that improves our quality of life?

Small stuff

One nanometre is one billionth of a metre (the average human hair is 100,000 nanometres wide). So as the name suggests, nanotechnology is about small stuff. To the average human brain, the scale is wholly unimaginable. But if you consider that 10 hydrogen atoms lined up will measure one nanometre across, it should become clear that nanotechnology is about making things on an atomic scale.

In many respects, nanotechnology is the ultimate convergent technology, pulling together skills and knowledge from just about every area of science: quantum physics, chemistry, biology, genetics, engineering and electronics.

The basic principle is to be able to fashion atoms and molecules to do what we want. But unlike chemical engineering, which traditionally looks at the properties of chemicals and then tries to figure out how they can be useful, nanotechnology seeks to manipulate molecules to perform specific tasks.

Molecular manipulation

In 1990, researchers at IBM in California, painstakingly manipulated 35 xenon atoms to spell out the IBM logo on a nickel crystal surface. At this scale it would be possible to write the entire contents of Encyclopaedia Britannica on the head of a pin.

Although of little practical value, this display of nanotechnology demonstrated its ability to see, manipulate and assemble individual atoms. It was a powerful message, because with these capabilities, and an understanding of how atoms and molecules interact with each other, it should be possible to build tiny molecular machines.

Indeed since 1990, other groups have managed to assemble molecular 'machines'. In another display of nanotechnology potential, Carlo Montemagno of Cornell University built a biomolecular motor one-fifth the size of a red blood cell.

Unlike the big machines we're used to, the traditional rules of physics rules don't apply to nanotechnology. Instead of crankshafts and pistons, Montemagno's motor consists of a protein from the bacterium Escherichia coli attached to a nickel spindle and propeller that's just a few nanometres across. Power comes from ATP (adenosine triphosphate), the biological fuel found in every living cell.

Grey goo

One of the first thoughts many people have when they consider nanotechnology is 'grey goo'. This refers to the nightmare scenario of self-replicating nanobots engulfing the world, laying waste to everything in their path. Like a swarm of locusts they would consume everything; except rather than eating plants, they would assimilate atoms and molecules to make new nanobots. Everything, all matter, would become one homogenous mass – a grey goo.

This fantastic scenario was first laid out by Eric Drexler in his 1986 book Engines of Creation, where he claims to have first coined the term 'nanotechnology'. The idea has since been popularised, at least in part, by Michael Crichton in his sci-fi book Prey, which describes self-replicating nanoparticles developing a swarm intelligence that leads them to assimilate all matter, including people. But as provocative as these depictions are, they still firmly belong in the realm of science fiction.

However, like all good caricatures there is an element of truth to the grey goo theory. Assembling devices on a molecular scale is, to say the least, a fiddly job that can be extremely costly. Some nanoparticles cost $750 a gram, 70 times more than gold. Given this, it's understandable why the idea of making self-assembling nano machines seems so attractive; although little progress has been made in achieving this yet. But self-assembling and self-replicating are two very different beasts. The former involves component molecules that connect together by themselves, whilst the latter implies changing atoms from one type into another.

It's perhaps because of this misconception that nanotechnology has acquired a reputation for being a kind of modern day alchemy. But with scientists' current capabilities, the prospect of turning water into wine is as far away from a reality as it's ever been.

Nanoparticles

Given the recent amount of attention nanotechnology has been getting in the media, it's easy to believe that it's a new phenomenon. But in fact we've been using nanotechnology for decades, centuries some would argue, in the form of nanoparticles.

Carbon black, a very fine carbon powder, has been used since the 1920s by tyre manufacturers to give them their black appearance and make them more resistant to wearing. Of course, the manufacturers had no idea they were using 'nanotechnology' and had no control over the size of the carbon nanoparticles.

More recently, nanoparticles have been used in sunscreens because of their ability to cover the skin so thoroughly. Manufacturers claim this makes the sunscreen more effective.

Other nanoparticles have been used to create paints that mop up smog by absorbing harmful nitrogen oxides from the surrounding air. Even car manufacturers, like Mercedez, have taken to adding nanoparticles to their paint to make it three times more resistant to scratches, so the companies claim.

One of the most studied types of nanoparticle are carbon nanotubes. Their unique cylindrical cage-like structure make them up to 150 times stronger than steel, yet just four times as light. Because of their unusual properties, scientists have claimed that nanotubes will be useful for a wide range of applications, from replacing silicon as the semiconductor of choice to generating electricity within the human body for medical advantages.

Nano medicine

But there is far more scope for nanotechnology than simply developing innovative nanoparticles. Although nano robots, or nanobots, still belong only in sci-fi books, there has been some significant work in making nano devices.

For example, some scientists have been working on implantable medical devices which, although larger than the nano scale, use nanotechnology to achieve their end.

Researchers at the University of Illinois have developed an implantable capsule for people with diabetes. Inside are pancreatic cells from a pig, which monitor glucose levels and produce insulin when required. Normally these foreign cells would be attacked by the patient's immune system, but a cleverly nano-engineered cage prevents this from happening. It's been designed with holes large enough to allow glucose and insulin molecules to pass through, but too small for the larger molecules of the immune system, such as antibodies and complement proteins.

The University of Michigan has worked on smart multi-purpose nano tools that can fight infection and damage within the body. Carefully chosen molecules, known as dendrimers, can deliver a drug inside a cell, measure its effectiveness and report back on the success of its mission.

Friend or foe?

Every so often there's a new enemy in science. Whilst genetic modification appears to be public enemy number one at the moment, it's probably fair to say that nanotechnology has already earned its place as runner-up, largely due to the grey goo scenario. But now there is concern that fears of the grey goo are distracting attention away from what could be real issues.

For example, what are the health implications of using nanoparticles in cosmetics and sunscreens? It's still not known whether the titanium dioxide nanoparticles used in sunscreens are able to work themselves deeper into the body or what the health consequences would be if they did. Studies have shown that other nanoparticles can have undesirable effects on living tissue. For example, nanotubes can produce an immune reaction in the lungs of mice, causing scarring of the lung tissue.

What might appear harmless in bulk form might not be so harmless in a nano-powder form. Indeed a Royal Society report has even suggested that nanoparticles and nanotubes should be treated as new chemicals under UK and European legislation, so that appropriate safety tests and labelling can be carried out on them. They should also be approved separately from chemicals in a larger form by an independent scientific safety committee before being permitted for use in consumer products, although such approval has already been granted for titanium dioxide nanoparticles used in sunscreens.

Some people are worried about the impact of nanotechnology on the environment, calling for a ban of nanotechnology until it can be proved safe. They point to a lack of regulation and toxicological information on nanoparticles. The figures might well justify their worries. Of the $700,000,000 spent on nanotechnology as part of the US Nanotechnology Initiative in 2003, a mere $500,000 was spent studying the environmental impact.

US researchers at the Center for Biological and Environmental Nanotechnology have suggested that the field is moving too quickly. They've expressed concern over the consequences of carbon nanotubes getting into groundwater. Nanotubes have a relatively large surface area and as a result other molecules have a tendency to stick to them. If nanotubes are able to spread far in groundwater, there is a danger they could assist with the spread of other pollutants that would normally not permeate very far.

With the objections raised to nanotechnology, it seems likely that it's in for a bumpy ride in the coming years. But given the difficulties in answering these questions over its safety, it may be some years before we know, once and for all, whether nanotechnology is indeed a safe science.

Find out more

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Websites

Biocapsule Provides Steady Insulin Supply
www.e4engineering.com/item.asp?id=43870&pub=ci&type=News
Article on an implantable capsule that releases a steady supply of insulin, which has been developed by biomedical engineer, Tejal Desai. There are links to the websites of the University of Illinois and the National Science Foundation.

Environmental Group Researchers Square off in Pollution Debate
www.smalltimes.com/document_display.cfm?document_id=4572
Canadian environmental organisation ETC has called for a ban of nanotechnology until it can be proved safe. This article looks at the arguments for and against.

The Future and Fear of Nanotechnology
http://popularmechanics.com/technology/
tech_tuesday/2004/2/tech_tuesday_2_3_04/
index4.phtml
Excellent article that looks at the ways that nanotechnology is currently in use: from Eddie Bauer who sells trousers with nanofibres that keep stains from settling in, to sunscreens with ultraviolet-absorbing nanoparticles that are so small, they cannot reflect light, and are thus invisible.

Committee Meets to Investigate Nanoscience
http://education.guardian.co.uk/higher/
research/story/0,9865,1009029,00.html
Article on a July 2003 meeting of scientists, engineers, environmentalists, and consumer and health experts to discuss the implications of nanotechnology.

The Institute of Nanotechnology
www.nano.org.uk
The IoN actively pursues the promotion of education and training; the provision of information to the public; the exchange of information between scientists; the coordination of projects; and the dissemination of developments throughout industry.

Nanotechnology – A Brief Introduction
www.zyvex.com/nano
Dr Ralph Merkle gives a brief yet detailed overview of the core concepts of molecular nanotechnology. Includes an exhaustive list of further reading, related articles, journals and websites. It also has details on the upcoming Foresight Conference on Molecular Nanotechnology.

NanoLink – Key Nanotechnology Sites on the Web
http://sunsite.nus.edu.sg/
MEMEX/nanolink.html
The website project managed by Memex Research Pte Ltd and the Internet Research and Development Unit. It provides a comprehensive list of websites working in the field of, or providing information on, nanotechnology and related areas. Includes numerous links to sites and studies and features a web-search facility for further investigation.

There's Plenty of Room at the Bottom
www.zyvex.com/nanotech/feynman.html
An online transcript of the 1959 talk by Richard Feynman to the annual meeting of the American Physical Society. It provided a startling glance into a future that is now coming true.

Thinktank Predicts Nanotechnology Backlash
http://education.guardian.co.uk/higher/
research/story/0,9865,894755,00.html
In February 2003, experts at one of the world's leading medical ethics think tanks warned of a growing backlash against nanotechnology. Find out more about it here.

Books

	Nanotechnology: A gentle introduction to the next big idea by Ratner (Prentice Hall PTR, 2002) As the title suggests, this is an easy to read overview and introduction to what can be an immensely complex subject. It includes details on the background concepts through to ongoing research and innovation. A useful guide for the non-scientific amongst us, it, where possible, explains the core concepts without resorting to complex mathematics. Get this book
	Hacking Matter: Levitating chairs, quantum mirages, and the infinite weirdness of programmable atoms by Wil McCarthy (Basic Books, 2003) Investigating the not-too-distant future of programmable matter: the ability to engineer solid matter, to vary its electronic, optical, thermal, magnetic and mechanical properties. Research continues within organisations as large and diverse as the US Defence Department and Levi Strauss. Indestructible denim or indestructible military hardware – the boundaries are limitless. Get this book
	Understanding Nanotechnology by Michael L Roukes (foreword) and Sandy Fritz (compiler) (Little, Brown, 2003) A look into the multitude of areas that nanotechnology may influence. From the ingestion of 'smart' molecules into the human body to hunt and destroy cancer cells, via the future of space exploration, to the revolution of all aspects of manufacturing, no area of modern life will remain untouched. Get this book
	The Spike: How our lives are being transformed by rapidly advancing technologies by Damien Broderick (Forge, 2002) A look beyond the jargon and enthusiasm of our headlong pursuit for the next biggest, or indeed smallest, innovation. Asks how we can hope to retain our humanity once we have the technical ability to alter, amend and specify the very building blocks of our own species. Get this book
	Microsystem Technology in Chemistry and Life Sciences by A Manz and H Becker (Springer-Verlag Berlin and Heidelberg GmbH & Co. KG, 1997) An insight into the multidisciplinary field of micro-system technologies applied to problems in chemistry, biochemistry and biology. Get this book
	Clones, Genes, and Immortality: Ethics and the genetic revolution by John Harris (Oxford Paperbacks, 1998) Can the rampant advances in technology be married to a considered and long-term ethical stance? Covering issues such as embryo research, screening and discrimination and commercial exploitation. Get this book
	Engines of Creation by Eric Drexler (HarperCollins, 1996) First published in 1986, Drexler claims to have coined the term 'nanotechnology'. He addresses the consequences of new technologies and the coming revolution of machines a thousand times smaller than a microchip. Get this book
	Prey by Michael Crichton (HarperCollins, 2003) The idea of nanoparticles was popularised with this sci-fi book, which describes the swarm intelligence that leads them to assimilate all matter, including us! Get this book
	The Diamond Age by Neal Stephenson (Penguin, 1998) Visionary science fiction writer who imagines a future transformed by nanotechnology. Get this book

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