Billion-pound atoms

CALIFORNIA futurist Eric Drexler has a utopian vision of a future so small it cannot be seen by the naked eye. Taking the trend towards miniaturisation to its ultimate extreme, he argues that in the next century mankind will manipulate individual atoms like Lego blocks. The tools he envisages are so wondrous they will introduce an era of plenty while curing many, if not all, of our greatest problems. Sub-microscopic robots will crawl through our arteries to scrape away the fatty deposits that cause heart attacks, test for toxic chemicals, or hunt down cancer cells. Others will build diamonds simply by arranging carbon atoms in crystal patterns. More practically, armies of them will erect whole buildings under instructions relayed by radio from computers. And people will have computer chips embedded in their heads to aid their memory.

It sounds a bit like 1940s predictions that, by now, everyone would have a personal aeroplane for commuting to the office, or clanking robots to do the housework. Arterial robots in particular conjure up images of the 1966 film Fantastic Voyage, in which miniaturised people were injected into a human body. But nano-technology is more than science fiction. Scientists have been exploring the physical limits of miniaturisation for a decade, and already some applications are beginning to make it to the market. Over the next 10 to 20 years, the field seems likely to grow dramatically. For canny companies and investors, there will be fortunes to be made.

Two unpublished studies, one commissioned by the European Commission, the other by a private think-tank, suggest nano-technology will be the second largest manufacturing sector in the world by the end of the next decade, topped only by the computer chip industry itself. A draft of one of the studies says the nano-tech market will be worth pounds 40bn by 2010. Multinational corporations from IBM to BAe, GEC and even Thorn EMI are showing interest. But the most innovative firms are likely to be those that will be spun off from university research programmes. "In Europe, there are expected to be 10,000 companies that will participate in, use and prosper from this technology," said a British scientist involved in both studies.

Exactly how much is being invested in nano-tech development in Britain is impossible to say. The Government has been funding research since 1988 through several different bodies, including the Engineer- ing and Physical Sciences Research Council. The European Commission has set up a network to link research projects with interested business, but scientists with corporate grants are cagey about revealing the amounts. Some, such as Ron Lawes, the head of the central microstructure facility at the Government's Rutherford Appleton Labs, worry that Britain will be left behind commercially as it was after inventing the micro-chip. Others say UK companies have learned their lesson and will be prepared to invest more as launch dates approach. It will be, say some, the next bio-tech stock market boom. Yet it is a subject little understood by executives in companies that might benefit from it.

One exception to that generalisation is John Searson, a director at Brook Corporate Finance, which is advising on the flotation of a pounds 15m investment fund that has taken an interest in some of the nano-tech projects at Birmingham University. While the fund's board may yet decide to back other projects, the nano-tech work is a promising candidate because there are potential commercial spin-offs starting right away. "Some of the instruments they develop may be sellable, which makes investment much more attractive," he says.

In its purest sense, nano-tech - derived from the Greek word for dwarf - applies only to things that can be measured in nano-metres, one-billionth of a metre. At that level, individual atoms can be discerned and manipulated. But between the atomic level and one half of a millionth of a metre (0.5 micron ) level of present day computer-chip technology lies a huge grey area where materials behave strangely. Even if the building blocks are made out of individual atoms, any working nano-device would likely be approaching the micron scale. So most experts use the term loosely to describe anything that size or smaller.

Nano-tech was first proposed by American quantum physicist Richard Feynman in a 1959 lecture. He challenged his audience to do two things, build a motor the size of a thumbnail, and write the entire Encyclopaedia Britannica on the head of a pin. The first was accomplished in less than a year; the second was only demonstrated after his death in 1988. Colin Humphreys, the Goldsmiths' Professor of Materials Science at Cambridge, used a scanning electron microscope to carve one page of the 29-volume set to the right scale, but the process took so long that the rest will have to wait. The project was not entirely frivolous. Professor Humph- reys suggests the technique could be used for storing the tonnes of records collected by governments and corporations that must be stored for years, but which are unlikely to be ever read again. "You could hold the British Library in the palm of your hand," he said.

Despite the ground-breaking Feynman lecture, the subject languished until Dr Drexler's book The Engines of Creation was published in 1986. Critics charge that he does more proselytising than research, but attendance at scientific conferences organised by his San Francisco-based Foresight Institute has been steadily growing. Most of the research is being done in the US and Japan, but Europe, including Britain, is still in the game. In the UK, scientists are working on nano-projects at several facilities, including Cambridge, Oxford, the Rutherford Appleton Labs and the universities of Glasgow and Birmingham.

Four techniques are currently in use by nano-technologists. At the larger end are the computer industry's traditional photo-lithography, which uses a chemical process to cut materials. At the other end is the Scanning Tunnelling Microscope, which uses a tip as fine as one atom across to "feel" atoms, and sometimes to push them out of the way. "The STM is pushing things around like a cue hitting billiard and snooker balls," says Richard Palmer, at the nano-scale physics research laboratory at the University of Birmingham. IBM scientists used an STM to make the first truly nano- scale structure in 1989, when they carved the company's logo by moving 35 Xenon atoms individually.

Scanning electron and X-ray microscopes have been reversed so that instead of magnifying a surface, they focus a tight beam able to cut into it like a laser. The microscope techniques are slow (carving IBM took 22 hours), cumbersome and expensive to use, leading some researchers to believe that the most practical production techniques will involve so called self assembly - using templates that take advantage of the natural tendency of atoms to arrange themselves in particular patterns. For example, Professor Palmer says one combination of copper and copper nitrite being used at the University of Birmingham naturally forms a nano-chess board pattern.

Most of the nano-tech that is likely to leave the laboratories in the near future will have little in common with Dr Drexler's vision of sub- microscopic robots. One company, Domino Printing Sciences near Cambridge, has used nano-tech to develop particles of ink so fine that they will not clog the tiny ink-jets used to print the sell-by dates on small packages. Bosch, the German automotive parts maker, is working on nano-tech sensors that will

provide accurate information about what each wheel on a car is doing in three dimensions. An existing application in the motor industry is the tiny sensor that releases air bags when it detects rapid deceleration. Probably the most lucrative area, however, is medicine.

At the University of Glasgow, cell biologist Adam Curtis and Chris Wilkinson, who holds the James Watt Chair of Electrical Engineering, are using nano- technology to develop new medical treatments. Their most advanced experiments - in conjunction with Ethicon, a subsidiary of Johnson & Johnson that makes sutures and implants - is a polymer that helps to repair severed tendons. Professor Curtis says a third of tendon surgery fails because the wounded tissue attaches to the channel in which it is supposed to move. Using photo-lithography - the technique used to make computer chips - the team is etching lines as shallow as 11 nanometres on to a polymer, which the surgeons would pack around the damaged tendon ends. Tendons in laboratory animals have found it easier to grow along the grooves than through the sides of the polymer, sharply increasing the chance of successful healing.

The team is also experimenting with other etched polymers to see how cells react to them. One goal is a material that would encourage cells to migrate to wounded areas and reduce the amount of collagen they secrete, thus reducing scarring.

Another medical application is being developed by Professor Lawes to help surgeons perform cataract operations. On an atomic level, even the finest scalpels work like chain saws, so Professor Lawes has developed a nano-tech turbine, powered by pressurised water. "Instead of hacking, it would rotate and gently mill away the effected part of the iris," he says.

There are also attempts being made to develop the sensors, valves and pumps need to build so-called smart pills, says Professor Lawes. These could be embedded in patients to release a precisely measured dose of drugs exactly when it is needed. For example, one of these pills could detect the amount of insulin in the patient's blood stream minute by minute and release exactly enough insulin to keep it in balance.

These components and others, such as the miniature steam piston demonstrated by America's Sandia lab recently, are likely to play an important role in building more complicated devices, such as Dr Drexler's nano-bots. Around the world, research teams are racing to develop ever smaller levers, cogs and switches. Richard Jackman, senior lecturer in electrical engineering at University College London, grew a diamond crystal on a template, then whittled it down with a laser to create a cog wheel 200 microns across. He figures that using his technique he could get it down to a diameter of one micron, but going any smaller would require techniques that are too slow to be commercially practical. While most research to date has used silicon because it is already common in the computer industry, he argues that diamond is a more durable substance for future nano-devices.

The other field where nano-tech is likely to have a large impact is optics and optical computing. Very precise lenses can be made by etching nano- patterns on to a transparent surface, much like the rings on a lighthouse lens. They can also be used to stop reflections and glare. One possible application, Professor Wilkinson says, is on spectacles.

Perhaps the most active nano-tech research is being conducted by the US and Japanese computer-chip makers. Professor Humphreys thinks that, like him, they are delving into one of the more unusual effects noticed on a nano scale with an eye on using them in optical computers. Silicon, from which semi-conductors are made, normally gives off heat - infra-red radiation - when a current passes through it. But at smaller sizes it emits a burgundy red light. "There is interest in this among the big chip makers, but it's going on behind the scenes," said Professor Humphreys. "There's an American organisation called Sematech set up by the US government to compete with the Japanese. I know they're working on this, and there's a huge effort at companies like NEC, but nothing's being published."

Professor Humphreys' work may be at the cutting edge of the new technology, but he fears there is little chance of it being commercialised by indigenous British companies. "The problem is that the UK no longer has an electronics industry that can exploit this work. We lost out in the silicon race. Now America controls microprocessors and Japan controls memory chips. It would require a government commitment to get back in to the mass market. You're looking at 10 years and billions of pounds."

One of the problems - and great advantages - with working on a nano scale is that materials do not behave normally. Stained glass windows possess their rich colours courtesy of nano-sized flecks of gold and silver which have lost most of their metallic properties. Substances that conduct electricity when in filaments half a micron in diameter, will not do so as individual atoms, says Peter Edwards, a professor of inorganic chemistry at the University of Birmingham. Another problem is that nano-tech devices tend to be fragile. They also lack power, said Professor Lawes. When the size of a motor is halved, its power ouput is reduced to one quarter of the original.

While there is little doubt that nano-tech will be a booming opportunity for business in the next decade, nobody is entirely sure what direction it will take. "There are a lot of exciting ideas, many of which won't happen and a few of which will be wild successes," says Dr Jackman. But will nano-tech lead to sub-microscopic robots, as predicted by Dr Drexler? While experts are agreed that it will result in a flood of new products, there is a division of opinion about this. "My advice is to be very cautious about some of the predictions," Professor Palmer says.

Malcolm Gower, a member of the EPSRC's Panel on the Nanotechnology Initiative, is more optimistic. "I would think in 20 years people will have nano-devices inside them monitoring and correcting problems," he said.

Professor Wilkinson takes the middle road, arguing that nano-robots are feasible but impractical. Given the time needed to make nano-components, a nano-robot could be as expensive as a private plane today.

There may be large amounts of money to be found in the tiny nano-tech world, but the routes to them are unlikely to be glamorous.