In the first stage of every big new technology, the world seems boundless. In the 1960s, for example, everyone imagined that the space programme would herald the beginning of space tourism and colonies on the Moon. Even cable television promised a better world - or at least home banking and distance learning - while early developments in biotechnology suggested a revolution that would extend to nearly every product imaginable.

Today, however, space remains a dangerous place for humans, cable television has settled into a one-way source of entertainment, and biotech really only applies to agriculture and medicine. The question facing us now is whether nanotechnology will suffer the same fate.

Well, the answer is yes, and no. While the space programme didn't bring colonies on the Moon, it did enable global positioning systems, improved weather forecasting and other technologies that have had a substantial impact on society. At the same time, the capabilities that were promised by cable television are now being delivered by the Web, and biotech has simply become more refined.

Nanotechnology will be much the same, but in this case the commercial applications will be less apparent. That's partly because a nanoparticle coating is a lot less obvious than a rocket, but also because of the deceptive meaning of nanotechnology itself.

Nanotechnology: what's in a name?

First of all, let's define what nanotechnology is. Most people in the field would agree that it should involve something that is 100 nm or less in size. However, if the definition stopped there, it would include nanoparticles of carbon black, a century-old material widely used in industry. It would also include much of semiconductors - indeed, former Intel chairman Craig Barrett claimed that everything Intel does is nanotechnology.

As a result, we insist that nanotechnology should also be novel and multidisciplinary. This excludes carbon black. It also excludes even the most advanced lithography techniques, since these are "just" a matter of making things smaller, in the same way as we have been doing in semiconductors for decades.

So what is sufficiently novel to be considered nanotechnology? At the top of the list are quantum phenomena, which includes not only quantum dots of various kinds, but other localization effects. Many of these stem from the large surface area of small particles compared with their volume, which affects properties such as melting temperatures and charge concentrations. Fluid mechanics also changes from being dominated by inertial forces to becoming dominated by surface charge and particle flow.

Quantum effects also enable light to be manipulated with sub-wavelength optics or through surface plasmon effects. Nanosized particles can even pass right through cell walls, perhaps for efficient drug delivery, perhaps as a dangerous toxin. And then there is the possibility of "bottom up" assembly - such as the way that DNA is copied or quantum dots are assembled - that opens up entirely new ways to fabricate and structure both materials and devices.

At Strategies Unlimited, we have been tracking the technologies and markets that are specifically related to nanophotonics products, which typically incorporate a number of the unique effects mentioned above. For example, companies such as Quantum Dot Corporation and Evident Technologies are working on colloidal quantum dots for applications ranging from medicine to the taggants that are used to prevent counterfeiting.

Other businesses, including LightSmyth, Luminus, Photonic Lattice and NanoOpto, are working on integrated holography and photonic crystals that require nanometre control of sub-wavelength structures, which could be used in filters and isolators, and for improving LED efficiencies. Meanwhile, Farfield Sensors, Nanofluidics and others are working on sensors for biomedical and biohazard detection, while companies like Konarka and Nanosys are working on novel photovoltaic structures that are more like photosynthesis than semiconductor solar-cell devices.

Research drives development

In the research arena, there is no doubt that the "nanotechnology" term will continue to appear in funding proposals and research papers for many years to come. One reason is the money on offer. Public spending on nano-related research projects in the US jumped in 2001 following President Clinton's nanotechnology initiative, and other countries and states have followed suit (figure 1). Although the growth in spending is now slowing, governments worldwide spend some $4 bn per year on nanotech projects. Corporate spending and private investment could bring the total to as much as $8 bn per year.

This spending may slow, or even decline, but will not disappear altogether. This is because unique effects emerge in the nano realm, and these must be better understood for organizations and countries to compete in future global markets.

Another, perhaps more important, reason is that policy makers, university departments, and professional organizations recognize the value - and also the complexity - of merging disciplines in order to exploit nanotechnology. Investment and patience are needed to cultivate a new way of thinking, and this is one of the most important challenges for nanotechnology: getting people from different disciplines to learn to solve problems together.

Products, not markets

However, the future of the term "nanotechnology" is slightly more complicated when it comes to the commercial world. First of all, customers buy products, not markets, and there is no single market for nanosized materials and devices. That said, the products are falling into three categories: nanomaterials, nanobiotechnology and nanoelectronics.

Nanotech is already a real commercial business in the materials industry. Existing products include nanoparticles of titanium oxide in cosmetics and sunscreens, while emerging applications include fuel cells with electrodes made from carbon nanotubes. Frankly, though, much - if not all - of the materials industry already deals with science at the nanoscale, so the arrival of "nano" is not a revolution. Nanomaterial science is just, well, material science.

Nanotech has also had some early commercial successes in biomedicine. Examples include the use of nanoparticles for drug delivery and for anti-microbial bandages, and the field is ripe for other novel ideas that can improve medical care and reduce costs. However, the biomedical industry also tends to think on an ionic or molecular scale, which means that the concept of "nano" doesn't impress anyone: nanobiotechnology is simply biotechnology.

Nanotech is certainly bringing novel ideas to the electronics industry, the most prominent examples being transistors and displays made from carbon nanotubes. Historically, carbon nanotubes have been closely identified with nanotechnology, so much so that any such transistors would certainly be considered "nanoelectronics". And a transition to nanotube transistors would be a monumental change - similar to the switch from germanium to silicon in the early days of electronics - since the semiconductor industry doesn't make major changes in its manufacturing process very often.

However, such a monumental development is unlikely. To succeed, the transition would need to be as seamless and painless as possible, since the semiconductor industry would not accept anything less. Even then, nanotube transistors would first only be used in a niche, such as in the central processing unit of a speciality microprocessor, or perhaps as a special type of memory. In fact, since nanotubes would need to enter so seamlessly, they would necessarily be regarded not as nanoelectronics, but simply as the contemporary incarnation of electronics.

Opportunities in photonics

Nanophotonic products are now emerging in each of these three categories. Two promising markets are high-brightness LEDs and solar cells, each of which are worth about $4 bn per year, with healthy year-to-year growth. A number of other products could also be attractive in smaller markets, especially for a company that can move up the supply chain to build a small system around its innovation.

Nanotechnology could also make a real impact in displays, by far the biggest market segment in photonics. Today, the total display market is worth almost $100 bn, several times larger than all of the other photonics markets combined. Remarkably, though, this huge market still does not have an ideal large-screen product. Even a small share in that important market would amount to a sizeable opportunity, and companies such as Motorola and NTERA are already working with large display manufacturers to develop screens based on carbon nanotubes and other novel structures.

Other nanophotonics opportunities are spread over a number of technologies and applications. If there is no real meaning to nanotechnology as a market, there is even less when applied to photonics, because of its highly diffuse nature.

The paradox of nanotechnology

This commercial reality means that the term "nanotechnology" will probably fade from discussions of the commercial market within the next 10 years. This is not because it has nothing to offer, but because any commercial developments will disappear into the myriad applications that they serve, rather than forming a monolithic "market".

The space programme and biotechnology were different. You may not think about Earth-orbiting satellites every time you switch on the television, but you are aware of the technology when the antenna is installed on your roof. And you may not know about the processes that make prescription drugs, or the way that your food is grown, but you can visualize an industry behind the innovations in these products.

Nanotechnology will not bring us the next space programme, or even a whole new industry built around nano-enabled products. But it might help us to develop the cure for cancer, more efficient fuel cells, or a better display technology. In other words, nanotech will improve the applications we already have, but in ways so subtle we probably won't realize that it's nanotechnology.

In general, these improvements will apply to the highest-end products - in other words, those products for which the suppliers can charge a higher price to justify the higher cost of introducing nanotechnology. This means that nanotechnology will first be used in small volumes of highly specialized products, many of which will be used by industry, not consumers. A few lucky companies might manufacture nanotech products in large volumes, provided that they are economical to manufacture. But nanotechnology does not usually come cheap.

The future of nanotechnology

In the future, research proposals and papers will continue to be peppered with the "nano" prefix. It is not a cynical ploy on the part of researchers to get recognition by using buzzwords. Nanotechnology is simply more tangible, more meaningful, in the R&D world, and the research world makes large shifts by organizing around central concepts.

At the same time, however, nanotechnology might not appear to be making any major commercial successes. But the successes will be there, it's just that customers won't need to know that they have been enabled by nanotechnology.

In short, nanotechnology will thrive as a unifying concept in the R&D world, but will get diffused seamlessly into commercial products. Remember, big new technologies do bring great things, but not how you may expect them to.