Nanotechnology is becoming the new eldorado, promising, among many other things, to combat climate change, provide renewable energy and clean water, and to cure cancer.
With the help of new tools like scanning tunnelling microscopes and atomic force microscopes scientists can now see and even manipulate materials at unthinkably minute scales, that of atoms and molecules.
A nanometre is 10-9 metre - a billionth of a metre or about 1/100,000th the width of a human hair.
Although there is no official international definition, nanotechnology is often described as dealing with objects from 1 to 100 nanometres in size.
According to microbiologist Dr Stephen Sowerby, of the University of Otago, nanotechnology is the fabrication of devices and materials to give control over the fundamental structure of matter.
He has been working with it since the early 1990s, when Prof George Petersen imported the first scanning tunnelling microscope in the southern hemisphere, making the university one of the leaders in the field.
"It's the move from working on molecules, where there's gazillions of them in one space, to working on them one at a time.
That is the real transition that's been made in the last 15 to 20 years," he says.
In one sense, nanotechnology is a scientific innovation, but living systems effectively manipulate atomic-scale matter in a very directed and concerted way, he said.
Nanotechnology offers an exciting opportunity to study how primitive living systems might have assembled themselves from the chemical building blocks available on Earth 3.6 billion years ago, he said.
Nanotechnology ranges broadly across many disciplines: physics, medicine, biology, chemistry - anything that deals with matter.
Scientists and engineers see it as a toolkit to develop new technologies and materials or make old ones work better.
Claims are made that these technologies may address some of the biggest challenges facing humankind, such as helping combat climate change by efficiently producing and storing cheap solar energy that will replace fossil fuels; providing potable drinking water by filtering polluted water with nanofilters; feeding the world with more efficient agriculture; developing more effective medical treatments, such as drugs delivered directly to specific cells by transporters like modified viruses, or the targeted destruction of cancer cells; even creating new life-forms and manipulating the inner workings of living cells - as well, of course, as generating jobs and money.
Some estimate that the value of products that use nanotechnology in some way will be worth more than $US3 trillion in the next five years.
The same sorts of promises were made a decade or more ago for genetically modified organisms (GMOs), and we are still waiting for their delivery.
Not only has there been a public backlash against that heavily patented technology, it is used mainly in developed countries, as poorer countries cannot afford it.
There are concerns that access to nanotechnology will follow the same trajectory and further divide the rich and the poor.
According to Assoc Prof Andrew Moore of Otago University, chairman of the National Ethics Advisory Committee, in the early stages of any new technology there are diverse speculations on both sides - that the technology will solve the problems of humanity, and also on the other, "Frankenstein" side.
Although little tends to be said about it, like all technologies, nanotechnology can be used in malevolent ways, such as in weapons or surveillance devices that preclude personal privacy.
David Berube in his book Nanohype: The truth behind the nanotechnology buzz (2006) claims almost everyone involved in nanotechnology has an ulterior motive for overstating how revolutionary nanotechnology is going to be, whether it is to attract research funding or venture capital, or bolster their reputations or those of their institutions.
The idea of directly manipulating individual atoms was mooted in 1959 by physicist Richard Feynman in a now-famous lecture, "There's Plenty of Room at the Bottom", at an American Physical Society meeting.
However, the nanotechnology drive was kick-started about 1986, with Eric Drexler's book, Engines of Creation, according to Dr Sowerby.
"It suggested that nanotechnological devices that are very similar in their behaviour to biological organisms might one day be available to manipulate matter in much the same way a living thing does, to build the devices and instruments," he said.
Drexler introduced the term "grey goo" to describe what might happen if a hypothetical self-replicating molecular nanotechnology went out of control.
More recently, Michael Crichton's thriller, Prey (2002), featured self-reproducing, intelligent swarms of killer nanorobots.
Thankfully, these scenarios seem to be in the realms of science fiction - at least for the time being.
Dr Sowerby says the fantasy and hype about the risks and the promises of nanotechnology tend to ignore some of the fundamental properties of atoms and molecules, which limit the degree to which they can actually be manipulated.
"What people are fantasising about in terms of building machines that are capable of building all sorts of nasty stuff, that is so far away I'm not going to see it in my lifetime.
"What I'd be more concerned about, myself, is if people tinker with biological systems and leverage off them," Dr Sowerby said.
Nanotechnology offers an alternative method of construction to the regular top-down method in which material is cut or shaped as required.
Bottom-up approaches aim to construct things from self-organising or self-assembling molecules, he explains.
"You can use the principles of crystallisation and the same principles organisms use to manipulate living matter and place the granules of matter in very discrete positions."
At present, much of the nanotechnology in commercial applications is based on nanoscale particles of materials already in use, rather than sophisticated nanorobots which appear to be some years away.
Their properties often differ from their conventionally sized counterparts and they behave in strange new ways because of their larger relative surface area and quantum effects which can change their usual optical, electrical and magnetic behaviour.
Opaque substances like copper may become transparent; stable material like aluminium oxide, commonly used in dentistry, turns combustible at nanoscale and is being investigated as rocket fuel; gold, which is normally inert, becomes soluble.
These different properties also mean there may be unexpected effects and risks to health and the environment.
An unexpected effect has already emerged in Australia.
From mid-2006, precoated steel roofing was found to be rusting prematurely, but the rust occurred in shapes like handprints or fingerprints.
It turned out that the nanoparticles of zinc oxide or titanium dioxide in sunscreen worn by the roofers were acting as a catalyst for the corrosion.
A paper on the catalytic effects of these nanoparticles on precoated steel showed that it depended on the structure of the nanoparticles - not all sunscreens containing them affected the steel coating to the same extent.
Andrew Maynard, science communicator, who reported this on his website (2020science.org), also reported the findings on the safety of such sunscreens by the Environmental Working Group (EWG), a US-based non-profit organisation committed to using public information to protect public health and the environment.
Unexpectedly, they found, on balance, zinc oxide and titanium oxide nanoparticle-based sunscreens were safer and more effective than many conventional sunscreens which exposed wearers to more UV radiation and a greater number of hazardous ingredients.
Zinc oxide and titanium dioxide have been used in sunscreens for years, as they filter both UVA and UVB light, but in normal forms they leave a white coating on the skin, whereas in nanoform they are transparent.
Nanoscale materials are already in use in a wide range of consumer products.
The Project on Emerging Nanotechnologies website (www.nanotechproject.org) lists about 800 products from many countries, including a few from New Zealand, which claim to use the technology.
Silver nanoparticles act as an antimicrobial agent in many things from clothing and disposable nappies to cooking utensils, food wrapping and appliances like fridges; incredibly light and strong, molecule-thick carbon nanotubes are used in sporting goods like tennis rackets or aeroplane construction; some cosmetics contain nanoscale particles like liposomes that deliver nutrients deep into the skin; nano coatings are used on self-cleaning windows and in electronics, where ever-smaller components store more information and process it faster.
The ability to machine materials to high precision could lead to benefits in many industries such as information and communication technology, automotive and aerospace.
Although some nanoparticles occur naturally in soils, and in the atmosphere from the sea, agriculture, traffic fumes and volcanic activity, their increasing use in products gives cause for concern.
Carbon nanotubes, if inhaled, may have similar cancer-causing effects to asbestos and some countries, such as Japan, have introduced health and safety regulations for people working with them.
A study published this week may be the first on the clinical toxicity in humans due to long-term exposure to nanoparticles.
It links the technology to two deaths and five additional cases of an unusual lung disease among workers in a Chinese factory. Although ineffective industrial health and safety practices are also implicated, it may mean "the emerging technology of the ultra-small could be in for a rough ride" according to Andrew Maynard.
Silver nanoparticles are intended to kill bacteria on food containers or prevent odour in clothing, but what happens when they get washed into sewage plants or waterways where they may affect fish and frogs and other life forms?
According to Prof Moore, one of the main ethical ideals is that you should do no harm to others, but there is little knowledge of the safety profile of nano substances or the toxic or other effects they may have on humans or the environment.
Some of the same issues that concerned GM, which is a form of nanobiotechnology, arise with other forms of nanotechnology, as they do whenever big companies, big investment, big research funds and big reputations, not to mention national competitiveness, are at stake.
These range from labelling which is not mandatory, the consumer's right to choose, and intellectual property rights, to the ethics of some of the proposed applications.
While some manufacturers claim they are already controlled under various existing safety regulations, such as those for food and drugs, the fact that nanoscale particles often behave differently from their normal-scale counterparts brings both advantages and risks.
Some of these, like the catalytic effect on rusting of titanium dioxide and zinc oxide nanoparticles in sunscreens, will be completely unexpected.
Many countries, including New Zealand, are looking towards regulating the use of nanoparticles, but it is a difficult task, especially in a global environment.
Unesco has published several reports on the ethics and politics of nanotechnologies in the past few years and it is five years since the British 2004 Royal Society/ Royal Academy of Engineering seminal report, Nanoscience and nanotechnologies: opportunities and uncertainties.
A recent review of that report by the Responsible Nano Forum reveals that not much has been done since to implement the recommendations on regulation, safety and toxicology, or even public engagement, although there were various attempts to hold focus groups about public opinion.
In New Zealand in April this year, a workshop sponsored by the MacDiarmid Institute of Advanced Materials and Nanotechnology, the Ministry of Research, Science and Technology, the Ministry for the Environment, the Bioethics Council and the Royal Society of New Zealand, discussed opportunities and challenges associated with nanotechnologies in this country, and how they should be handled.
According to an evaluation of the workshop by Bruce Small and Erin Smith, from AgResearch, some of those attending noted concerns that scientists did not want outside governance of nanotechnology, but neither did they want to take ethical responsibility, preferring to leave that to the market.
Because of the broad sweep of applications of the technology, it is not clear which department should co-ordinate the governance of nanotechnologies, according to Simon Wright, senior science analyst for the Ministry for the Environment.
There are high tech and multidisciplinary implications as well as socio-political ones, both positive and negative.
The unknowns are huge and normal risk assessment does not work, he said.
Nano in a nutshell
> Nanotechnology deals with objects from 1 to 100 nanometres in size.
> A nanometre is 10-9 metre - a billionth of a metre or 1/100,000th the width of a human hair.
> Scientists and engineers see nanotechnology as a toolkit to develop new technologies and materials or make old ones better.
> Nanotechnology is currently used in electronics, cosmetics and clothing as well as many other consumer goods.
> Possible future uses include producing and storing cheap solar energy; filtering polluted water with nanofilters; medical treatments, such as delivering drugs directly to cells using tiny transporters.
> Possible problems include risks to health and the environment due to unexpected behaviour of substances in nano form.
Useful websites
> www.morst.govt.nz/current-work/roadmaps/nanotech/workshop-2009/
> http://2020science.org
> www.nanotechproject.org
> www.crnano.org
> www.nanowerk.com
> www.goodnanoguide.org
> www.responsiblenanoforum.org/
