Probing mind

Oxford University Professor George Smith has the ear of academia, industry and government alike.

The government is clamping down on universities in a bid to get them to produce clear results and applications for their research. Academics are now asked to justify their aims, set out their plans and speculate on their likely conclusions — or their funding is pulled.

While on the surface this seems a sensible approach, Oxford University’s Prof George Smith views it as dangerous and damaging. Industry may benefit in the short term, he believes, but we will lose a whole generation of future technologies.

Sceptics might be tempted to dismiss Smith as an academic moaning from his ivory tower. But, as head of the university’s pioneering materials science department and chairman of an up-and-coming UK nanotech firm, his warnings should not be lightly dismissed. Smith’s Oxford materials department has an all-industry advisory panel made up of directors of technology from Rolls-Royce, Qinetiq, BNFL and Hewlett-Packard, and they back his researchers to seek out the materials that their engineers will use tomorrow, rather than the cautious research he believes the government is forcing.

‘Our work lies at the interface between basic science and engineering,’ said Smith. ‘It is often bold, risky and exciting but if it pays off it will bring enormous returns. We should be doing adventurous research not just incremental and minor tweaks to existing technology. The major new advances should come from us.’

Materials science has come a long way since the days of simply studying steels and alloys. Today, materials researchers solve problems such as how to deliver drugs to specific areas of the body with sticky polymers or creating computers that can store information on the nanoscale. ‘The subject has grown and diversified,’ said Smith. ‘Its roots are in metallurgy but now it has almost exploded into new areas.’

Oxford University’s research on fusion reactors is among its most exciting work. In October last year a team headed by Dr Steve Roberts embarked on a £2m project to find the materials for a reactor capable of containing a small star on Earth. The work is clearly timely with mega-projects in the pipeline like ITER, the first large-scale test of nuclear fusion as a source of clean energy.

Professor George Smith is Head of the Department of Materials at Oxford University.

‘There is an underlying, almost visceral feeling in the science community that fusion is now becoming feasible,’ said Smith. ‘The improved understanding of plasma physics has clearly persuaded the science community that it’s worth investing billions of pounds to demonstrate the next stage of scale up.

‘Now we’re going to actually build the reactors so we need to think of how to engineer a system and environment in which it will work,’ said Smith. ‘The only successful containment solution today is on the scale of the sun, which uses the force of gravity to solve the problem!

‘It’s incredibly hot and not far away from what’s going on in a star — there is an intense flux of neutron radiation,’ he said. ‘We need materials that won’t generate nasty and undesirable long-lived isotopes or degrade as a result of long-term exposure to neutrons. Also higher-energy neutrons yield things like hydrogen, which promotes crack propagation.’

The prime option for building a reactor is ‘low-activation’ steel, with fewer alloying elements that can become highly radioactive. The team will look at exotic materials like vanadium too. There are also regions of the reactor that need to cope with hot gases and plasma interactions, so the researchers are investigating thermal barrier coatings applied with a plasma spray.

Oxford is contributing a strong background knowledge of steels and how they degrade in radioactive environments, said Smith, and in the past the university defined and tested the materials used to build the Sizewell B nuclear fission reactor.

Elsewhere in the materials department researchers are working on quantum information processing, using nanoscale ‘qubits’ to build a computer that could theoretically solve problems in a fraction of the time taken today. One way to achieve this is by printing tiny silicon ‘quantum dots’ on to a semiconductor substrate.

The department is also awaiting a £4.5m funding announcement from EPSRC for a five-year project that could link solar power with hydrogen storage. The team plans to optimise polymer materials for solar cells and improve reversible electricity storage in hydrides so charged fuel cell energy can be released later in a cheaper and lighter manner than conventional batteries.

In parallel to co-ordinating his department’s research, Smith acts as a non-executive chairman to UK firm Polaron. The company focuses on more conventional technologies like lighting for most of its business, but Smith heads Oxford nanoScience, the dynamic nanotechnology wing of the group, which is now selling a device Smith and colleagues developed at the university. The 3D Atom Probe is an imaging tool that creates a picture of the atoms in a substance, allowing its nanoscale properties to be viewed in 3D. So, for example, metal degradation in a nuclear reactor could be spotted earlier.

‘The probe effectively peels off the atom layers and builds up a 3D image of a material like geological strata,’ said Smith. ‘The atom probe is a quantum leap in what we can do.

The earliest versions of atom probes only had a pinhole detector, unlike our wide-angled position detector, and so gave an image like a geological borehole in a single dimension.’

The device uses a 2,000V pulse to push the atoms off the surface of a sample, where they are picked up by a wide-angled detector. ‘It was very difficult to do. It’s like listening for the sound of a pin dropping shortly after a bomb has gone off. You’re listening for a very sensitive signal with all the echoes from the high-voltage blast in the background.’

The company plans to develop the technology further for semiconductors, which are not conductive enough to shed atoms with an electrical pulse, so the researchers will use a nano-pulse laser. The probe could map dopant atom distribution, for example. If dopants form clumps rather than disperse equally it can affect the electrical properties. X-rays are used to analyse electronics today, but further moves towards miniaturisation will require nanoscale devices like the atom probe.

The company has so far sold over 10 of the machines, costing £500,000 each. Customers include computer disk maker Seagate, which is using the probe to increase storage capacity, and Japanese steel giant Nippon, which intends to develop new materials using the device. Science minister Lord Sainsbury singled out the technology in a speech in January to promote research links between the UK and China, a country that Smith is also creating ties with in his department via seminars and tours to Beijing.

Developed by Professors George Smith, FRS & Alfred Cerezo at Oxford University, the Three Dimensional Atom Probe (3DAP) is capable of mapping the chemical identity and 3-dimensional position of individual atoms within a conductive sample with single atom depth resolution and sub-nanometer lateral resolution.

For the Atom Probe and other work Smith will this year be awarded one of the highest commendations in materials science: the 2005 Acta Materialia journal Gold Medal, given to those who make outstanding contributions to the field.

His experience and expertise also led to an invitation last year to speak to the Parliamentary and Scientific Committee, which briefs MPs on issues where science and politics meet. So his view that the government is pushing university research too hard is clearly taken seriously.

‘Industry wants the new and sometimes wacky ideas for the future to bring in new technology and different ways of thinking. The industrialists we speak to are emphatic about that,’ he said. ‘There is a dictionary definition of a material that says it is a “useful substance”. Well, materials science is a useful science.’