UK invests in the nano world

by Paula Gould

The Engineering and Physical Sciences Research The EPSRC has identified the ‘nano world’ as one of its Council (EPSRC) is one of seven agencies that priority areas for funding over the next few years. distributes funding for research and postgraduate This decision reflects the growth in investment that the Council has already pledged – or, indeed, spent – training on behalf of the UK government. The EPSRC on projects involving dimensions and tolerances in invests around £500 million ($800 million) each year, the range 0.1 nm to 100 nm (Table 1). Funds for with a view to sustaining and enhancing the UK’s nano-research are drawn from separate EPSRC science and technology base. The Council’s support Programmes, reflecting the underpinning and for nanoscience and nanotechnology has almost interdisciplinary nature of the subject (Table 2). The tripled over the past four years. This is partly the Materials Programme has played a particularly result of targeted funding schemes, but also the significant role in supporting this work. Today’s appearance of more ‘nano’ proposals in the standard research into areas such as molecular self-assembly, novel patterning techniques, precision metrology grant applications. The EPSRC now boasts a tools, nanostructured materials, and electro- substantial and diverse research portfolio in mechanical systems could form the building blocks of nanoscience and nanotechnology. tomorrow’s materials science and engineering. There are two main routes though which the EPSRC invests in nanoscience and technology: ‘strategic’ and ‘responsive mode’ funding. The distribution of strategic funding is in line with deliberate policies to support certain areas or activities, and generally follows a specific call for proposals. Candidates most likely to make good use of the money may also be encouraged to apply. The remaining portion, which accounts for the majority of the EPSRC’s investment in nano-oriented work, is allocated via the responsive mode. “We feel that it affords researchers the

For further information: greatest flexibility to develop their own innovative ideas and Engineering and Physical Sciences Research Council, address adventurous research challenges,” says Clive Hayter, Polaris House, North Star Avenue, EPSRC materials programme manager also responsible for the Swindon SN2 1ET, UK URL: www.epsrc.ac.uk coordination of nanotechnology activities within the Council.

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Table 1 EPSRC expenditure to date on nanoscience and technology* on directly relevant and underpinning research (data provided by EPSRC). Glasgow, York, Cambridge, Nottingham, and Southampton, as Year Directly relevant Underpinning well as the National Institute for Medical Research. 1997-1998 £11.4 m ($18.2 m) - The Cambridge-led nanotechnology IRC will similarly 1998-1999 £11.5 m ($18.4 m) £107.7 m ($172.3 m) foster interactions between researchers from the university’s 1999-2000 £11.7 m ($18.7 m) £117.1 m ($187.4 m) 2000-2001 £12.8 m ($20.5 m) £133.5 m ($213.6 m) departments of engineering, physics, chemistry, materials 2001-2002 £20.2 m ($32.3 m) £152.8 m ($244.5 m) science and metallurgy, as well as in the life sciences, while 2002-2003 £32.2 m ($51.5 m) £147.1 m ($235.4 m) working in partnership with University College London (UCL) *Note: annual expenditure figures do not necessarily reflect all funds committed to projects. and the University of Bristol. An additional £5 million ($8 “It is the research community itself determining research million) deal has also been signed with the Japanese Funding strategy. But where we identify national priorities, we then Agency to allow IRC members to engage in a five-year act in a strategic manner.” collaboration with the Nanomaterials Institute of Tsukuba. Hayter explains how the Council identified one such As director of the Cambridge-led IRC, Mark Welland is national priority during the late-1990s, following an responsible for its budget, about 30% of which will be assessment of the EPSRC’s strengths and weaknesses in directed towards ongoing ‘core projects’. The projects will nanoscience and nanotechnology. The exercise revealed that focus on nanofabrication, characterization techniques based UK researchers had particular expertise in extreme on scanning probes, theoretical modeling, and smart nanotechnology, nanofabrication, and molecular biomaterials. nanotechnology, he says. However, the assessment noted The remaining 70% will be allocated to shorter-duration how few projects involved cross-disciplinary research. Since ‘exploratory projects’, lasting from a few months to up to the nano realm cuts across subject boundaries, a decision three years. Though precise areas for these exploratory was taken to set up two Interdisciplinary Research projects have yet to be defined, proposals should mesh with Collaborations (IRCs) to facilitate innovative research the IRC’s four main objectives: to fabricate complex three- through collaboration. dimensional structures with molecular precision; to A call for IRC proposals in nanotechnology went out in determine the mechanical and electronic properties of 2000. After much consideration, the panel eventually nanoscale interfaces; to control the growth and self-assembly selected two: a nanotechnology IRC led by the University of of soft layers (such as human tissue) by directed self- Cambridge and a bionanotechnology IRC at the University of assembly on patterned substrates; and to produce . Each received a promise of £10 million ($16 million) architectures for new devices in biomedicine and information to support a six-year programme of research. The EPSRC technology (IT). Attainment of these aims is expected to pledged the majority of the funding, with additional involve a truly interdisciplinary approach, combining ‘hard’ investment from two other UK funding agencies (the inorganic materials with ‘soft’ organic materials, and drawing Biotechnology and Biological Sciences Research Council and on the expertise of all participants. the Medical Research Council) and the UK government’s IRC researchers have already identified a number of Ministry of Defence. possible novel structures and associated applications that might result from the work. These include photovoltaic Pulling together Table 2 Breakdown of funding directed towards the ‘nano world’ from Both IRCs are expected to draw on a critical mass of EPSRC programmes (data provided by EPSRC). researchers, offering a concentration of advanced Materials 52% instrumentation and promoting excellence through research IT and computer science 19% and training in an interdisciplinary environment. Physics 14% Chemistry 6% The bionanotechnology IRC in Oxford will foster links Basic technology*5% between the university’s physics, chemistry, biochemistry, Life sciences interface 2% Other 2% engineering science, physiology, and materials departments, *A joint research councils initiative. while also drawing on expertise from the universities of

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Fig. 1 Scanning tunneling microscope images of (a) a Si surface (where red represents the atoms and green the chemical bonds) and (b) a crystal of titanium disilicide growing on a silicon surface. (Courtesy of Mark Welland, IRC in Nanotechnology, University of Cambridge.)

devices that are reliant on molecular chemistry and nanoscale fund a project in 24 hours,” Welland says. “If somebody patterning to engineer charge separation, peptide-based approaches the management committee and says: ‘I want to coatings that are capable of controlling cell adhesion to start this project and I have an exceptional person who can implants, and photonic devices that are grown from directly begin next week,’ we can make a decision right away. And we assembled block copolymers. The list is deliberately have done this already.” incomplete, reflecting the IRC’s desire to pursue promising Despite being envisioned as a virtual center of excellence, research trends and exploit as yet undiscovered phenomena. the nanotechnology IRC has a physical home in a new “We need to place the money very carefully, and we need to purpose-built nanoscience facility in Cambridge. The EPSRC place it in areas that build on our strengths and give us a funding has also helped UCL and Bristol secure additional competitive edge,” Welland says. “Being flexible lets us do investment for new laboratories and offices. These state-of- this. It’s more work, but it does mean we can target areas the-art premises will help enormously in realizing the effectively.” underpinning vision of collaborative working, Welland says. The informality of the funding process and relative “We made sure our facility was designed as something that absence of bureaucracy allows fast decisions to be made. The all departments could have access to,” he says. “This is an IRC can invest in rapidly emerging areas of research, which is interdisciplinary research collaboration. You really do have to essential in such a fast-paced area. The high level of mix chemists, physicists, materials scientists, and engineers, investment in the US, Korea, and Japan, for example, is especially at the postgraduate and postdoctoral level.” generating an intensely competitive research arena. “We can John Ryan, director of the Oxford-led bionanotechnology IRC, agrees that the cross-departmental aspect is an important part of the IRCs. Research at the interface between scientific disciplines can be a lonely enterprise without proper support, but has the potential to make significant advances in science and technology, he says. Projects funded under the bionanotechnology IRC will consequently bring together scientists from the life sciences and physical sciences, maximizing opportunities for sharing different skills and approaches. The Oxford-led collaboration aims to investigate biomolecular systems from the level of single molecules to complex systems, establish their functionality, and apply the new-found knowledge to the production of useful devices for Fig. 2 Biomolecular electronic device: cytochrome c molecules attached to a single- walled carbon nanotube. (Credit: Jason Davis, .) a range of industries and applications. The IRC will meet

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these goals by drawing on its existing strengths in biological molecular motors, functional membrane proteins, and biomolecular electronics and photonics, says Ryan. For example, researchers may mimic the way proteins convert electromechanical energy into mechanical work, using hybrid constructions of existing biological motors or wholly synthetic materials. Such machines could eventually be used to power nanoscale devices or transport materials. Detailed investigation of the structure/function relationship of ion channels, hormone receptors, and photoreceptors at an atomic level is also planned, using X-ray diffraction and solid- state nuclear magnetic resonance (NMR) techniques. Membrane proteins show considerable potential for photonic applications, while carbon nanotubes (CNTs) and DNA Fig. 3 A high-resolution transmission electron micrograph showing intergranular film in a oligomers may prove to be suitable molecular wires for silicon nitride ceramic. Researchers at the University of Oxford are investigating how the structure of such thin films affects the ceramic’s properties. (Courtesy of Markus electronic devices. Considerable emphasis will be placed on Doeblinger, University of Oxford.) self-assembly mechanisms in these systems, according to Ryan. “There is little propensity for inorganic materials to use applications; the University of Sheffield, for exploration of self-assembly, but the things biology comes up with by using soft nanotechnology; and the University of Oxford, for self-assembly are quite remarkable,” he says. “This has projects in the nanocharacterization and nanofabrication of opened up a huge area of research.” materials. Work is currently under way to recruit at both the For example, the materials department at the University of postdoctoral and postgraduate level. On the latter front, the Oxford is using its platform grant to develop existing IRC will benefit from a new EPSRC-funded doctoral training strengths in electron microscopy and microfabrication center at Oxford, established with a £5.3 million (Fig. 3). Researchers are currently engaged in a number of ($8.5 million) grant. The center will support 50 students projects to characterize nanostructured materials using high- over a five-year period, and house facilities for postgraduate resolution transmission electron microscopy (HRTEM). The training in all interdisciplinary research areas. work is expected to further the understanding of the unique properties of novel nanostructures, such as CNTs, which could Sharing skills potentially be exploited in the future. Collaboration and communication, both within and between In one such project, researchers are performing structural research groups, is being promoted explicitly through the characterization and spectroscopic evaluation of halides EPSRC’s series of ‘platform grants’. The grants are linked to grown within single-walled CNTs. The team has already generic areas of research, rather than specific projects, and shown that this extreme spatial confinement causes the cover a longer time period than standard research grants. This crystals to grow into a one-dimensional rather than a three- enables recipients to adopt a broad outlook towards scientific dimensional structure. The work will also push the boundaries and technological problem solving, build more flexibility into of TEM to the limit. HRTEM images generally contain the ongoing investigations, and retain critical expertise. imprint of the microscope itself, and these aberrations need Platform grants are awarded, after a competitive review to be removed, explains David Cockayne, professor of process, to groups that have already demonstrated proven, materials at the University of Oxford. The researchers will world-leading expertise in one of the EPSRC’s priority areas. have access to a state-of-the-art TEM, designed to their own To date, the EPSRC has awarded four such grants in specifications, which is expected to produce aberration-free nanotechnology to: the University of Birmingham, for images of the nanoscale crystal structures. The high- research into nanostructured surfaces; Cranfield University, resolution structural data will be compared with theoretical for work on thin film ferroelectrics for nanotechnology models and atomic-scale electron energy-loss spectroscopic

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(EELS) measurements gathered using the TEM’s optimally projects might not have known about or realized were monochromated electron source. This will build up a possible.” complete, real-time picture of the unusual one-dimensional Another EPSRC platform grant at the University of crystal structure. Sheffield is focusing on soft nanotechnology. The funding is The same techniques will also be used to investigate the supporting two research assistants, one with expertise in behavior of single atoms placed inside buckyballs. EELS will polymer chemistry and the other with a background in reveal important information about the atom’s state, says physics, who will play an integral part in a joint Cockayne. The project may have implications for the design physics/chemistry department effort to engineer soft, smart and development of quantum computers if atoms trapped in materials that mimic the structure of biological organisms. molecules are chosen as the quantum bits, or The materials’ softness is an integral part of the project, ‘qubits’. Quantum operations and read-out from such a explains Richard Jones, who is a professor of physics at the computer would be performed by electron spin resonance of University of Sheffield and co-responsible for managing the the encapsulated atoms. Knowledge about any electron loss grant. Nanoscale structures operate in an environment where from trapped atoms is consequently crucial. “We want to strong surface forces dominate. These forces, under the know when we put the atom inside the buckyball what its influence of Brownian motion, can be used to manipulate a state is like,” he says. “Does it lose some of its electrons to soft material and guide it into a certain position, but might the surrounding buckyball or not?” have no effect on a rigid structure. Hard materials are also The researchers are also trying to develop precision unlikely to react to changes in their surroundings, whereas a nanofabrication techniques using a focused ion beam system. flexible nanostructure may change shape according to its ‘Top down’ nanofabrication beyond the optical domain is temperature. This responsive change in shape is the regarded as a first step towards advanced manufacturing mechanism behind biological motors, explains Jones. processes and the production of novel materials with “Our soft nanotechnology programme is an attempt to sub-100 nm dimensions. Scanning a Ga ion beam across a take those general principles about having very responsive material cuts the surface, just like a laser saw, says Cockayne. materials, exploiting self-assembly, exploiting the The critical difference is that the ion beam is capable of environment that exists at the nanoscale, and trying to etching patterns with nanoscale dimensions, which can, in reproduce them,” he says. “Obviously nature is very turn, manipulate materials’ properties in hitherto unexplored sophisticated and has had billions of years of evolution to get ways. Focused ion beam patterning of thin magnetic films it right, so we’re trying to do very crude things in can be used to produce so-called anti-dot arrays, a possible comparison, but still in the same spirit.” future information storage medium. The ion beam can also For example, the Sheffield researchers have been working help researchers to extract very small volumes of materials, with weak polyacids, which react differently to acidic and for example semiconductors, to provide samples for further basic conditions. A lump of gel made from such a material characterization. shrinks in acid and swells in bases. Studying the same The EPSRC’s platform grant is supporting these projects by behavior at the nanoscale will reveal the mechanism for funding two research assistants with specific skills in the shape-change, hope the researchers. To do this, the team techniques that underpin the two areas. These individuals must first grow a single molecular layer of these responsive play an important role in directing research, and effectively polymers, which is a complex task in itself. Atomic force enabling the department to make the most out of its existing microscopy (AFM) and neutron reflectivity techniques will be intellectual and physical resources, says Cockayne. “We have used to characterize the polymer chains. “The chemistry is really excellent instrumentation here for microscopy and difficult, it’s not trivial, and requires a lot of different skills. related techniques, and we wanted it to be used and On the physical side, we need to find techniques to make developed at the highest level,” he says. “You really need sure these layers really do swell and collapse in response to skilled people who not only know how to use the instruments their environment,” says Jones. “The platform grant allows us themselves but can see how they can be used in specific to perform these technologies that we need to put these projects. They can suggest ideas that the people running the visions into practice.”

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Next generation optical nanometrology. The majority of current optical Jones has also been involved in setting up a Masters course in microscopy techniques are unable to resolve structures nanoscale science and technology. The one-year course, smaller than the wavelength of light, limiting resolution to organized together with the University of Leeds, is one of the order of 300 nm. The ultimate goal, says Richards, is to four such courses that have been initiated under the EPSRC’s develop optical microscopy with true nanometer spatial targeted promotion of nanotechnology Masters Training resolution. Such a technique would open the way for Packages. As the name suggests, these courses are intended complete characterization, via optical spectroscopic analysis, to train up the next generation of scientists and engineers of a biological or nanostructured material. with interests in the nano world, and prepare them for future Richards’ work, which is looking specifically at Raman work in academic or industrial R&D. scattering as a nanoscale characterization tool, is supported The Sheffield/Leeds Masters course is now in its third year by a three-year EPSRC research grant. Raman spectroscopy and is going from strength to strength. A total of 13 physical provides a ‘chemical fingerprint’ of materials, but is many science graduates enrolled for the first year. Numbers orders of magnitude weaker than normal fluorescence, says expanded to 20 for the 2002-2003 academic year, and 26 Richards. This rules out approaches to nano-optical candidates started this year’s course, Jones says. The course microscopy, where light is directed through a tiny hole at the got off the ground thanks to the EPSRC’s financial support of end of an optical fiber, he explains. Instead, the researchers studentships, although the course now attracts self-funding have opted for ‘apertureless scanning’, using a probe tipped and externally sponsored students too. Many opt to pursue with a Ag or Au nanoparticle. Moving the nanoparticle probe further research in nanotechnology at the end of the course, tip across CNTs or thin-film polymers, for example, should Jones says. “It’s our experience that they’re genuinely very induce enhanced Raman scattering in surface molecules, enthusiastic about the pace of science and technology they’re hence producing an image of that surface. exposed to on this course,” he says. “Once the basics are understood we can go forward and Nick Quirke, professor of physical chemistry at Imperial actually start to think about developing the technique College London, notes a similar enthusiasm among students further, so ultimately it could be used in the same way that a on Imperial’s new nanomaterials Masters course. Organizers scanning confocal microscope or AFM is used routinely now expected eight students to enroll when the course started by nonspecialist users,” Richards says. “But that point is last September, but they ended up with 50% more. The certainly a long way away. We are still trying to understand course comprises a mix of theory and practice, with time set the underlying physics of the problem and what needs to be aside for lectures and hands-on training in experimental and done to make this approach realizable.” computer simulation techniques. “The students we have He notes that the realization of many nanoscience taught have found it challenging, but very rewarding,” says applications is first going to require robust measurement Quirke. techniques. After all, how can you exploit the properties of a new material or device if you can’t quite see what you have Breadth and depth created or how it’s behaving? “AFM is great for telling you Most of the EPSRC’s investment in nanoscience and what you’ve got in terms of surface relief, but it won’t tell technology is delivered through responsive mode funding as you about chemical properties. Scanning tunneling standard research grants. This is an ongoing process – microscopy provides phenomenal resolution but only of applicants may submit a proposal at any stage throughout conducting systems, and electron microscopy requires that the academic year – and projects vary widely in nature and you put your system in a vacuum, which may not be scope, reflecting the huge diversity of nano-oriented research desirable. So my feeling is that the development of optical being pursued in UK universities and research institutions. tools that can also probe these length scales is important in “We support a complete spectrum of activity, from helping to provide feedback for the development of fundamental research to more applied projects,” says Hayter. nanotechnology,” he says. For example, David Richards of the department of physics In contrast, Adrian Leyland, senior research fellow in the at King’s College London is working towards the ‘holy grail’ of engineering materials department at the University of

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Sheffield, has been working on a project with more First, the researchers are assessing which of three immediate technological applications. His research into the promising nanotechnologies is most suitable for constructing production of metallic coatings, applied via physical vapor quantum computing circuitry. The three candidates are: a deposition (PVD), could be of great value to the automotive wholly molecular approach; an optical approach, which industry, among others. involves self-assembled quantum dots; and a single electron- Thin PVD ceramic films are currently used to improve the based approach using nanofabrication. The most promising wear resistance of cutting tools and, increasingly, engine and will then be used to construct a prototype circuit – a simple drive-train components in high-performance cars. Researchers logic gate that handles at least two qubits of information – on the three-year, EPSRC-funded project at Sheffield are as the basis for subsequent development into a quantum trying to develop nanostructured PVD coatings for similar computer. “There is certainly no prospect whatsoever of applications, but with improved performance. To do this, making a full quantum computer within the timescale of this Leyland’s team is mixing metallic components with ceramics, research programme,” says Andrew Briggs, professor of as well as testing wholly metallic films. “Ceramic coatings materials at the University of Oxford. But, he adds, “I think it exhibit high hardness, but metals with a lower elastic is essential for the health of the subject that there are modulus add toughness,” Leyland says. “The challenge is to experimental successes, because that will indicate the value manipulate the structure of predominantly metal coatings to of the theoretical work that has already been done and, of achieve adequate hardness while retaining sufficient course, act as a spur to further theory.” elasticity.” The team has found that many metallic nanocomposite Strong foundations coatings provide hardness in excess of 20 GPa, and in some The EPSRC’s strategic investment in nanoscience and cases approach ‘superhardness’ levels of 40 GPa, while nanotechnology – whether through establishment of IRCs, maintaining a low elastic modulus. This is especially instigation of enabling platform grants, ongoing responsive important for wear-resistant coatings that are deposited on mode funding, or sustained support for graduate training low-strength, low-modulus substrates such as low-alloy initiatives – has laid good foundations for future research in steels and light alloys. An elastic mismatch between coating the UK. So much so, says Hayter, that the need for targeted and substrate could cause the coating to fail prematurely funding schemes is now greatly reduced. “We have a very when under strain. vibrant portfolio of research activity now coming forward in “We do have applications in mind, but PVD is perceived as responsive mode, and there is a strong argument now that being an expensive process. It also requires a vacuum there isn’t a need for central coordination any more,” he says. chamber, which limits the size of component we can treat,” This ‘vibrant portfolio’ ranges from investigations into says Leyland. “Realistically, we are at a point where certain fundamental nanoscience through to highly applied niche applications exist, but in the longer term the key to nanotechnology. Topics cover top-down nanofabrication widespread exploitation will be in transferring know-how to techniques, precise nanomeasurement tools, nano- more traditional coating technologies, like thermal spraying electromechanical systems, molecular technology, and electroplating.” nanoparticulate technology, nanostructured materials, and In a bid to nudge nanoscale R&D closer to market, the bottom-up, self-assembly devices. EPSRC is helping UK researchers form collaborative The Council is hopeful that much of its investment in basic partnerships with commerce through Foresight LINK awards. research will help generate wealth for the UK, given a The EPSRC provides 50% of the funding, with industry picking suitable time frame for technological development. Both up the remainder. Seven nanotechnology Foresight LINK Welland and Ryan are optimistic that the Cambridge- and projects have been funded so far. One such award enables Oxford-led nanotechnology IRCs will spawn practical researchers from the universities of Oxford and Cambridge to applications as well, though perhaps not immediately. “We work with staff from Hitachi Europe to develop components want to see spin-out funding, and that’s already happening,” for a quantum circuit. The project’s aims are ambitious, but Welland says. “Our aim is to build a very strong nanoscience highly specific. knowledge-base, from which new technology will evolve.” NT

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