ARTICLE ARCHIVE
Practical nanotechnology
Nanotechnology is constantly finding itself in the headlines. But are microscopic machines an inevitable part of our future, or just another hype-heavy get-rich-quick ruse?
August 2002
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As comments like Chase's make clear, the concept of nanotechnology has been getting increasing visibility over the past few years. Long a staple of science fiction, references to nanotechnology are now just as likely to appear in company prospectuses or courtroom transcripts. In the same way that vague visions of e-business drove
Western economies in the late 1990s, nanotechnology has become an early candidate to define our views of science, technology, and business in the next century. Is that outlook justified, or will the nanotechnology hype prove to be so much hot air?
Nanotechnology 101
In its most basic form, nanotechnology refers to the manipulation of materials at the atomic or molecular level. The name derives from the nanometre, a scientific measurement unit representing a billionth of a metre. To use an oft-quoted comparison, a human hair is between 100,000 and 200,000 nanometres thick, while a typical virus can be just 100 nanometres wide. Atoms themselves are typically between one-tenth and half of a nanometre wide. Because of the difficulties involved in working at this scale, activities involving manipulation of items as "large" as 100 nanometres are generally included in the concept of nanotechnology.
Most discussions about nanotechnology race fairly quickly away from the intricacies of molecular manipulation itself and onto the sexier futuristic concept of nanomachines or nanobots: microscopic devices that can themselves carry out tasks at the atomic or sub-atomic level.
A Time overview of how the next century will progress gives a typical vision: "They will be building our cars one molecule at a time, invading our bloodstream to declog our arteries, and replicating themselves thousands of times over."
A frequently used point of reference is the 1966 film Fantastic Voyage, in which a team of scientists (including Raquel Welch) are miniaturised, placed in a tiny submarine and injected into a sick man's bloodstream. Given that nanotechnology invariably involves work on a much smaller scale than the average blood cell, we suspect the popularity of the reference has a lot to do with the widespread desire to have Raquel Welch anywhere in your body. It also reflects one of the trickier elements involved in nanotechnology: the imaginative leap required to envisage something that damn small.
It's important to note that this kind of atomic construction isn't a particularly new concept. Physicist Richard Feynman first raised the idea of building machines out of individual atoms in 1959 when he famously observed: "The principles of physics, as far as I can see, do not speak against the possibility of manoeuvring things atom by atom." Feynman's paper, There's Plenty of Room at the Bottom, is a classic text for nanotechnology, alongside Eric Drexler's 1986 book Engines of Creation, which examined the ethical issues associated with this rapidly evolving field. (After that, you're plunged fairly quickly into the impenetrable world of scientific journals.)
Advances in technology since Feynman's and Drexler's work have made nanomachines a more realistic prospect, particularly the development of electron microscopes capable of basic (if slow) molecular manipulation. However, the fundamental concept hasn't yet changed. If you can construct objects at the molecular level, you can theoretically build anything, since all objects are made up of molecules.
Translating from concept to practice is trickier. While many plans have been drawn up for simple nanomachines such as gears and motors, actually building them is still fiendishly difficult and rather expensive. The most famous "working" nanomachine is probably the nanoguitar constructed by Cornell University researchers in 1997.
Just 10,000 nanometres wide, the nanoguitar has six strings, each just 50 nanometres wide. Of course, without a nano-ear to listen to its 10MHz output, the guitar is fairly useless, but it demonstrates that simple machines can be constructed on a nanometric scale.
Producing nanomachines on a commercial basis will undoubtedly prove more challenging, since atomic manipulation, while not theoretically contrary to the laws of physics, is still extremely slow and costly.
Nanomachines are also built using a "bottom up" process, unlike most current manufacturing processes, which use "top down" processes to make changes to existing materials. As such, researchers are working in largely uncharted territory.
The most widely discussed long-term solution is to make the nanomachines self-replicating; what better way to build a microscopic machine than have a microscopic machine do it?
Control mechanisms for such systems (how does a machine know how to build a copy of itself, and how does it know when to stop doing so?) are still in their very early stages, and once again theory is a fair way ahead of practical reality.
Another major issue is the question of whether nano-constructed objects will actually behave in the same way as their natural equivalents. Some nanotechnology research is explicitly designed to produce objects that differ from natural ones, such as glass that is transparent but shatters less easily. Unlike the glass, it is far from clear whether an object built molecule by molecule will have equivalent characteristics to its real-world double, especially since most objects we recognise and understand are massively complex in molecular terms.
"We are just beginning to understand how to use nanotechnology to build devices and machines that imitate the elegance and economy of nature," Charles Vest, the president of MIT, observed recently. "The gathering nanotechnology revolution will eventually make possible a huge leap in computing power, vastly stronger yet much lighter materials, advances in medical technologies, as well as devices and processes with much lower energy and environmental costs.
Nanotechnology may well rival the development of the transistor or telecommunications in its ultimate impact."
While we wait for that revolution, nanotechnology is already producing useful results. It may be a while before nanoguitar-toting micro-bands are shooting up the chart, but some research projects are demonstrating real-world usefulness right now.
Many of the more recent practical applications of nanotechnology don't actually involve full development on a nanometric scale, even though they draw heavily on the theories involved with the field. Much recent development has been in the area of materials research, but scientists believe that transistors could also eventually be built in this way, paving the way for computational technologies which don't depend on silicon and which can pack even more circuitry into microscopic spaces.
Nanotechnology of this type is also being explored for potential medical applications, although we're unlikely to see these in Raquel Welch's lifetime.
Real world uses
One nanotechnology-based development which has been widely discussed recently is IBM's Millipede storage technology. Millipede can achieve a storage density of up to one trillion bits per square inch. This is 20 times larger than the best storage densities that can be achieved with conventional magnetic media. IBM achieved this feat by using thousands of 10-nanometre tips to punch data onto a plastic recording surface treated with a nanometres-thin silicon coating.
"Since a nanometre-scale tip can address individual atoms, we anticipate further improvements far beyond even this fantastic terabit milestone," said IBM Fellow and Nobel laureate Gerd Binnig "While current storage technologies may be approaching their fundamental limits, this nanomechanical approach is potentially valid for a thousand-fold increase in data storage density." IBM hopes to release a more substantive commercial prototype based around Millipede technology in 2003.
Nanotechnology is also impinging on processor design. Recent linked studies by Harvard in the US, Delft University in Norway, and Lucent's Bell Labs division have constructed working molecular logic circuits using a variety of methods. Harvard built its circuits by overlaying nanowires (thin ridges comprising just a few atoms) to create simple connections. Delft concentrated on using nanotubes capable of conducting electricity to build the circuit, while the Bell team built its circuit organically by applying a chemical to a silicon surface. Although the circuitry built so far is fairly simple in each case, these first steps make it more likely that a practical means of building processors at the atomic level will eventually appear.
Whether that will be necessary in the near future is debatable. Intel has demonstrated processors that work on a nanometric scale still being designed using traditional silicon-based methods. With models already boasting structures just 20 nanometres in size, the processor giant argues that change won't be needed any time soon. "We still have not found a fundamental limit for making silicon transistors smaller," Intel Fellow Dr Robert Chau declared last year. "The pace of silicon development is accelerating, not decelerating."
Other uses continue to emerge in materials science. Research by the University of Texas has uncovered a method of purifying natural gas using "nano-sand", a specially developed polymer membrane.
Conventional purification methods use large amounts of energy, making the new technology more environmentally friendly and cheaper to implement. General Motors in the US has already begun using a "nano-clay" thermoplastic olefin (TPO) composite, including flakes that are just one nanometre thick, to build a step used on some new model vehicles released in 2002. Compared to conventional plastic, the nano-clay version is lighter, more resistant to cold and easier to recycle, and costs about the same to manufacture.
"Although the step-assist is a simple, low-volume part, we see this as a significant and exciting first step that opens the door to increased use of TPO-based nanocomposites in future vehicles," says Alan Taub, executive director of science for GM Research and Development.
On a more personal level, a company known as Nano-Tex is working with "molecularly engineered textiles" that, for example, minimise wrinkling, or absorb sweat particles and don't release them until they come in contact with a detergent. The practical upshot?
You can wear the same clothes to go jogging for a week without stinking up the neighbourhood. Potentially, such fabrics could also make use of nanoscale circuitry to measure your heart rate while you jogged.
Perhaps the most commercially successful example of nanotechnology in action has been the development of nano zinc oxide, used to produce see-through sunscreen and other healthcare products. Developer Nanophase credited the product with boosting its revenues by 172 percent when it introduced the product in 2000, and it continues to be a strong seller for the company.
Whether driven by an urge to minimise BO, cut sunburn, or store more data, nanotechnology is already starting to attract significant investment dollars. The NanoBusiness Alliance, an industry association, estimates that US nanotechnology startups will receive US$1 billion in funding this year alone, while the US government will pour US$1.3 billion into nanotechnology research over the next two years. The Japanese government is even keener, assigning US$14 billion for nanotechnology efforts to help bolster its key electronics industries.
Those nanotechnology dollars are on top of the sums spent by major technology vendors such as IBM, Hewlett-Packard, and Intel, all of whom have recently announced innovations and research based on nanotechnology concepts. Even Microsoft has distracted itself from legal woes and .NET spruiking to explore the potential applications of nanotechnology. Oddly, Microsoft research sociologist Marc Smith is exploring the potential impact of medical nanobots, sagely predicting: "We will be eating a lot of computers in the future." (Whether Windows causes people to vomit remains to be seen.)
Few scientists are willing to turn away scarce research dollars, but some are concerned that the growing interest in nanotechnology (especially where it overlaps with trend-hungry Silicon Valley) may ultimately cause more problems than it solves. Just as Internet companies frequently took themselves public without establishing a clear market for their products, nanotechnologists are facing pressure to form public companies and explore commercialisation opportunities well before their research is completed.
Indeed, many newly developed degrees in nanotechnology explicitly include a business component, moving the emphasis clearly from scientific advancement to commercial potential. The concern amongst researchers is that over-eager scientists may take funding and fail to produce results, thus reducing the available pool of capital for future research. "We all hope we can avoid the painful foolishness of the Dot Boom cycle," Vic Kley, president of General Nanotechnology, wrote recently.
Where does Australia sit?
Ever since the US government allocated US$500 million to its National Nanotechnology Institute in 2000, pressure has been growing in Australia for similar initiatives to develop our national nanotechnology resources. While such funding levels are unlikely to be matched given current Federal spending priorities, Australia does have a fairly well developed capacity in nanotechnology.
A 2001 conference hosted by the CSIRO to assess Australia's nanotechnology strengths identified three main areas of existing research strength: nanoparticle research, nanotubes, and biometrics. The existence of national research organisations such as CSIRO was also seen as a potential benefit.
"The field is still open and the potential for Australia to lead in this area is very strong because of its existing science strength areas and its multi-disciplinary organisations and links which are already in place," the conference concluded.
Many Australian universities now boast dedicated nanotechnology degrees. Flinders University in Adelaide offers a Bachelor of Science in Nanotechnology, the first such course anywhere in the world, and has a dedicated chair in nanotechnology.
Similar degrees are also offered by the University of New South Wales and Curtin University of Technology in WA, while the University of Technology in Sydney boasts a Bachelor of Science in Nanotechnology Innovation.
Research centres have been established in many tertiary institutions. These include the University of Queensland's NanoMaterials Centre (specialising in industrial materials), the University of Wollongong's Intelligent Polymer Research Unit, and UTS' Institute for Nanoscale Technology (specialising in biomedicine and energy efficient particles).
Recent government initiatives have encouraged some prominent nanotechnology researchers return to Australia. Last year's Federation Fellowships scheme, designed to ensure skilled researchers are not forced offshore due to lack of resources, saw a number of nano-scientists take up $225,000 a year grants.
On the medical front, Dr Frank Caruso returned to Australia from Germany to continue his research into nanoscale engineered bioparticles, which could be used for delivering medications to highly specific locations in the body. In materials research, Professor Yiu-wing Mai took up a fellowship at the University of Sydney to study polymer nano-composites, which could be used to develop new manufacturing materials. University of NSW Professor Robert Clark received a fellowship to continue research into quantum computing, which could eventually lead to nanoscale computing devices.
What comes next?
Just as the popular image of nanotechnology is in the still largely theoretical realm of nanomachines, popular fears about where nanotechnology might take us tend to centre on the hackneyed notion of self-reproducing robots roaming out of control. "It may be that the world will end up needing a nanotech immune system, with police nanobots constantly at microscopic war with destructive bots," Time reporter Michael Lemonick speculated (with no obvious evidence) in 2000.
While that problem may not arise, the potential social impact of widespread nano-manufacturing is a topic that's rarely discussed. The potential threat to employment represented by the late twentieth-century shift to computerisation seems small compared to the possibility of a manufacturing process that requires human planning, but no human involvement. As nanotechnology becomes more advanced, discussions of its potential medical impact are also likely to increase involvement.
For now, the reality is a little more prosaic. Even the most ardent supporters of nanotechnology believe it will be decades before most of these ideas are practical, and some observers take an even more sceptical view. "While researchers are making steady and incremental progress in many areas, there have been no epochal nano-breakthroughs," Wall Street Journal columnist Lee Gomes noted recently. "In other words, nothing analogous to the 1974 discovery of gene splicing, which launched the biotech industry."
The biggest challenge is to develop the fundamental research underpinnings of nanotechnology, which will be an expensive task without immediate commercial reward, even if the long-term impact is immense. Further research may also throw up further roadblocks. For instance, nanotechnology enthusiasts are fond of pointing out that nanomachines don't contradict existing laws of physics, but tend to forget that those laws have undergone some radical shifts in the past century.
"There are many applications envisaged for nanotechnology," says Professor Jani Matisons, nanotechnology professor at Flinders University. "But if we don't understand some of the fundamental principles that govern nano-structures, the accurate placement of such precise structures, and the interactions of such structures in a very confined environments, we will not get applications beyond the initial simple ones that are already out there."