GLOBAL ROADMAP FOR CERAMICS 2006

Report of the 1st International Congress on Ceramics 25-29 June 2006, Toronto, Canada

A report prepared for the UK Ceramics community with the aid of support from the Engineering and Physical Sciences Research Council, September 2006

Edited by Robert Freer, School of Materials, University of Manchester

Robert.Freer@manchester.ac.uk

1

Contents Introduction 2 Reports of individual symposia 3 Electronics 3 Energy 10 Environment 16 Glass and Optical Materials 19 Multiple Applications 24 Consumer Products 32 Biology and Medicine 34 Transportation 38 Innovation and Invention 41 Common Messages from Symposia and Roadmapping 44 International Trends and Business Perspectives 44 Electronics 44 Energy 45 Environment 46 Glass and Optical Materials 47 Multiple Applications 47 Consumer Products 48 Biology and Medicine 48 Transportation 51 Innovation and Invention 52 Contributors to the Report 54

2

INTRODUCTION The full report of the 2006 Global Roadmap for Ceramics (to be published by the American Ceramic Society) will include the texts of the 63 invited and 11 plenary presentations given at the 1st International Congress in Ceramics, held in Toronto (25-29 June 2006). All speakers were asked to give a vision of the developments and status of their specialist area in the coming 10-20 years. It was clear that a number of presentations restricted their overview to past and current activities. It is possible that the final published versions of such papers may be more forward-looking and insightful. However, this report, prepared in the first instance for the UK ceramic community, is based on the oral presentations given in June. The meeting was structured around a number or core themes:

• Electronics • Energy • Environment • Glass and Optical Materials • Multiple Applications • Consumer Products • Biology and Medicine • Transportation • Innovation and Invention

Reports from each of the symposia are reported in sequence, including relevant plenary presentations. The final section brings together the common threads from the major symposia and the Roadmap highlights. The names and affiliations of the 10 contributors to this report are given on page 54. The support of the Engineering and Physical Sciences Research Council for the contributors is gratefully acknowledged.

3

ELECTRONICS ELECTRONICS I Duane Dimos (Sandia National Laboratory)– Integration and process strategies in advanced microsystems. It was argued that advanced ceramics have enabled the Information Age. With the coming of the second silicon revolution, with more responsive systems, there will be opportunities in: Microelectronics – high and low k dielectrics (ferroelectric BST and PZT films) MEMS – structural films and piezoelectric sensors Microelectronic Circuits –microwave dielectrics and superconducting components Integrated optics Microelectronics – Ferroelectric capacitors (FCAP) – currently 0.2µm x 0.2 µm; these are thin films with low temperature processing (following CMOS protocols); the complex topography means the need for conformal technology (MOCVD). There are opportunities for the volume production of smart cards. However as the processing technology becomes more complex (and expensive), there needs to be a compelling reason to move to a new material; back-end integration reduces the cost for the introduction of new materials. Hybrid Integrated Systems, for example

(i) (Ba,Sr)TiO3 (BST) capacitors, integrated and tuned, and (ii) Pyroelectric arrays with 50µm pixel elements.

Process control is the key to hybrid integration, eg pO2 adjustment to control point defect chemistry (in BST films etc). MEMS – the challenges include managing stress developments within the fabricated systems; opportunities exist for chemical sensors (microchemical laboratory) and these will need high quality mesoporous films as preconcentrators and for chemical selectivity. Multilayer Packages and Components The industrial trend for advanced electronics is towards multifunctional packages. The multilayer structure provides opportunities for functionality, but the challenges are predictable co-firing with substrate, assessing the effect of microstructural evolution and reaction on performance and the integration of passive components. Evolving technologies of importance to Low Temperature Cofired Ceramics (LTCC) include Direct Write for co-fired MCLL (via micropen), and Robocasting for slurry deposition. Nanoscale Materials Integration There are many opportunities for the exploitation of controlled nanoparticles and quantum dots in, for example, photonics, catalysis, street lighting, chemical/biosensing and energy storage. Taking examples of self-assembly processes (based on ZnO) it was shown that by varying the temperature or composition that the

4

geometry of the rods can be controlled. From the work in the laboratory, the obvious questions are (i) can the process be scaled? and (ii) at what price? Christian Hofmann, (EPCOS Austria), System in Package Solutions for LTCC In developing materials for the communications markets, a variety of fabrication technologies are employed for products intended for applications at frequencies in the range 10MHz to 10GHz. The baseline knowledge for such developments is an existing library of at least 400 formulations. In addressing the requirements for an LTCC Roadmap, the System in a Package (SIP) has a number of critical parameters including the linewidth (reducing from 75µm to 50µm; 2002 to 2007), the tape thickness (reducing from 30µm to 25µm) and the tape itself, changing to lead-free. The associated LTCC requirements are an increase in functionality combined with reduction in size. For RF applications the SIP requirements are: integration ability; materials compatibility and robustness. For the automotive sector a wide range of applications can be combined into a single module (electro-hydraulic module). For electromagnetic interference protection, there is a move to modules based on ZnO (replacing ZnO varistors). The ZnO grain boundaries control dielectric properties and protection properties. With an effective relative permittivity of 460, the modules provide both resistance and capacitance functions. The system in a package (SIP) approach needs materials know-how, needs system know-how and a combination of LTCC and electroceramics, yielding new SIP solutions. These can be tailored to give the requisite electrical, mechanical and thermal properties. For the future:

(i) Need to increase integration - this is limited by the current understanding of the materials

(ii) Need to increase functionality – this is commercially expensive if individual components and the systems fail

(iii) Will need new materials for some applications. Clive Randall (Pennsylvania State University) Multilayer Capacitors and Actuators: Materials Science Challenges Current multilayer capacitors (MLCs) have up to 800 ceramic layers (≥0.9µm thick) in a single product. In the laboratory MLCs with 1000 layers of 0.5µm thickness have been demonstrated. There is a continued move to higher capacitance and smaller volume to maximise the volumetric efficiency. This has resulted in reduction in layer thickness of typically 25% per year. Thus from 0.5µm in 2007, it is predicted that it will reduce to 0.2µm in 2010 (which will be difficult to achieve for X7R products), and to 0.1µm in 2013 (at this stage it will be necessary to relax the –55ºC performance specification for capacitors). The emerging submicron MLCs will need:

(i) Nanosize powder technologies for BaTiO3 based dielectrics (ii) Interface control between electrodes and dielectrics (iii) High reliability – new tools to aid development cycle

5

(iv) Revolutionary build-up technology at 100nm scale. There will be a move away from traditional fabrication technologies.

(i) Nanosize powder technologies for BaTiO3. In the first instance there is the oxalate route for the dielectric, but the nanosize nickel powder (for the electrodes) is close to the limit of the production technique. Possibly a self assembly molecule (SAM) route may be appropriate to lay down nickel layers.

(ii) Interface control between electrodes and dielectrics. In very thin layers the interface between the ceramic and the electrode will become unstable; there are tensile stresses in the Ni layers, and grain size incompatibly between BaTiO3 and the Ni. One way forward is to develop Ba-Ti-Ni alloys at the interface (4-15nm thick). However, this could lead to a catalytic effect with very different local pO2 values from that which is expected. It may be necessary to design new materials, for example including Cr component (to prevent formation of an interface layer), but these may break down at high electric fields. Inclusion of Pt or Ir would give greater oxidation resistance, but would be more expensive.

(iii) Reliability. Need specialist techniques to investigate MLCs at local level. For example voltage contrast facility in Focussed Ion Beam (FIB) instrument, to enable detailed local analysis.

PZT Actuators. Need 2µm electrode layers, fast response and cost of $6-10 per fuel injector actuator. This means reducing cost, and moving to Pd-Ag electrodes. Unfortunately low temperature electrodes (eg 850ºC) with flux will degrade the properties of the actuator. With Pd-Ag electrodes there will be a range of low fire effects; with Ag electrodes there will be significant interface problems. A second issue for PZT actuators is the need to understand fatigue/degradation effects. Important Issues for the future include:

• Interfacial interactions; defect chemistry; electronic/ionic migration effects; size effects.

• New characterisation techniques, for example FIB/voltage contrast for local investigations.

ELECTRONICS II Shunpei Yamazaki (Semiconductor Energy Laboratory Co. Ltd. Japan), RFCPU Substrates and Nonvolatile Memories In the first talk, by Shunpei Yamazaki of Japan’s Semiconductor Energy Laboratory, the audience was presented with a very personal view of the historical development of non-volatile “flash” electrically erasable programmable read-only (EEPROM) memories. The key to such technology is the floating gate metal-oxide semiconductor (MOS). Kang and Sze of Bell Labs in 1967 were the first to publish the design of a floating gate memory, but theirs was based on metal (Zr). Yamazaki’s contribution to the field was a Si floating gate structure with the control gate wrapped with an

6

insulating film, and devices made by SanDisk, Intel, Toshiba, Spansion, etc. are all based on his original patent of 1970. Challenges to be overcome in the future as these devices become ever smaller and the density of electrical components greater include the possibility of malfunction by capacitive coupling as the floating gates become too close to each other. The possibility of charge leaks due to the very thin insulating layers is also a problem, as is the size of the charge, which necessarily becomes smaller and smaller. The future combination of CPUs with non-volatile memories with an RF interface would, it was argued, open up new markets in the radio-frequency integrated circuit (RFIC) tagging industry as well as the non-volatile memory industry. Hiroshi Tamura (Murata Manufacturing Co. Ltd. Japan) Trends in Microwave Materials for Low-Temperature Co-Fired Ceramics The second talk, Hiroshi Tamura gave the audience an overview of low-temperature co-fired ceramics (LTCCs), which are used in both chip monolithic devices integrating passive elements (filters, duplexers, baluns, couplers…) as well as functional circuit boards (RF modules of mobile phones, automotive electrical control units…). LTCCs are composed of borosilicate glass and crystalline fillers. High-K and low-loss materials are desired for the miniaturisation of devices. First-generation materials included CaZrO3 (CZG, K = 25, Qf = 3500, TCC = 0) and BaO-Al2O3-SiO2 (BAS, K = 6.1, Qf = 1500, TCC = 100 ppm/ºC), developed in the early 1990s. The second generation of materials included MGC (K = 25, Qf = 3300), which consisted of MgAl2O4, glass, plus a secondary crystalline phase (Mg3B2O6 and/or Li2MgSiO4). An extra sintering step is required to devitrify the glass and thus increase Q. LTCC substrates for circuit boards are required to have ultra-flat surfaces and minimal distortion. In order to achieve these properties, a constrained sintering (or zero-shrink) technique can be used. Dupont and Matsushita developed an Al2O3-glass (AWG) material (K = 8.7, Qf = 1000, TCC = 140 ppm/ºC) whilst Murata reported an Al2O3-CaSiO3-glass material (K = 8.6, Qf = 1500, TCF = -70 ppm/ºC), both of which can be produced by constrained sintering, in which the green body is placed between two sheets of Al2O3 and fired. The Al2O3 prevents any shrinkage/distortion in the xy plane. Third generation materials (RWG) evolved by adding rare-earths to these compositions. The Al2O3-glass-BaSm2Ti4O12 material has K = 15.1, Qf = 2800, and TCC = -5 ppm/ºC and can be co-fired with Ag electrodes in air. Future challenges for LTCC development include producing them larger (20cm x 20cm), thinner (< 1mm), flatter (< 5µm in 4x4 mm), and stronger (> 300MPa). Making LTCCs with cavities is also desirable. New techniques allowing the co-firing of high-K and low-K materials, as well as both dielectric and magnetic materials and the embedding of chip components in substrates were also proposed for the future development of advanced multifunctional LTCC devices. Donald Bray (Poco Graphite, Inc., USA) Semiconductor Processing: The Use of advanced Ceramics In the talk by Donald Bray of Poco Graphite, Inc. the audience was presented with a view of the semiconductor industry with respect to the ceramics used in the

7

manufacture of wafers. Significant technological changes are sweeping through the semiconductor industry – the switch from 200mm to 300mm wafers and the ever increasing circuit density along with the ever decreasing line widths (current technology is 130nm, while on paper the industry has planned nodes at 65nm in 2007 and 45nm in 2009). Moore’s Law has held true for the past 40 years, and Intel’s new Italium chip contains 410 million transistors per cm2. As integrated circuit manufacturers strive to make their chips faster, smaller, and cheaper, semiconductor fabrication equipment companies become more reliant on advanced ceramic components. Wafer processing is becoming more advanced, with higher temperatures and more corrosive environments. The need for new materials is increasing. Indeed, an International Technology Roadmap for Semiconductors (ITRS) already exists; and the chief concerns as far as ceramics involved in semiconductor manufacturing include their extremely high purity (target of 1ppm or less), low particle generation, and tight control of electrical properties (dielectric constant, dielectric strength, and volume resistivity). Structural properties are of only secondary importance, although ceramics used in lithography must be very stiff (SiC is a good choice). ELECTRONICS III Brian Sunderlof (IBM, USA) Ceramics in Electronic Packaging The roles of packing in electronics are that it must be mechanically and thermally stable. Must match the thermal expansion coefficient of Si, and be thermally conductive. Multilayer packaging involves the co-firing of ceramic tapes with interconnects, such as Al2O3 with Mo and glass ceramics with Cu. The complexity and size of green sheets increases in line with the demand of the electronics. At present green sheets 215 x 215 mm, with up to 200,000 vias per sheet as small as 50 µm diameter. Sheets are 50 – 375 microns thick. The processing of the tapes along with the thermal treatment and sintering schedules must be optimised to ensure high throughput whilst maintaining yield and tolerance targets. At present, 200 W / cm2 thermal management is used. Connections are getting so small that alpha emission causes soft, non-permanent errors – leads to a driving force for purer materials with a lower concentration of metals which contribute to alpha emission. This has serious cost connotations. Roadmap 200 W / cm2 at present will have to rise to 800 W / cm2 by 2012 – may require fluid channels in order to remove heat. Fluid channels pose a huge technical challenge and are non-desirable. The speaker was asked how small can vias go – he replied that 37 µm was the limit for current technology. A certain cross section of metallization is required to carry the current to the electronics, and big problems with yield occur as things get smaller.

8

The speaker was also asked what fundamental materials science would improve packaging, to which he replied that many studies have been carried out, such as the use of catalysts to reduce the burn out time by 30 % Danilo Suvorov (Institute Jozef Stefan, Ljubljana Slovenia) Designing Materials for Glass-Free LTCC Modules LTCC (low temperature co-fired ceramics) allow for the development of complex devices on one chip, such as the R-, C- and L components for microwave antennae, and are able to reduce the number of manufacturing steps required to make a device out of discrete components – an entire system can be fabricated in one firing step of around 4 hours. A number of challenges present themselves, however, due to the potential incompatibilities (chemical, thermal and mechanical) of the various material types which encompass the LTCC device. In order to increase microwave frequency of operation (up to 30 GHz) improved dielectric properties must by realised. The size of a component scales with the permittivity, so as a device gets smaller, the permittivity must increase. In addition, it must be possible to limit the variation of properties (such as the resonant frequency in a microwave device) as a function of temperature. A large drawback in LTCC devices in the shrinkage which occurs during sintering, which is greatest in the thickness direction. With tight processing control, however, this may be kept within a narrow window. Glass phases are often used in order to broach the low sintering temperatures required to densify ceramic components, whilst maintaining the integrity of metal interconnects (< 850 °C). The introduction of a glass increases the level of interaction types, which inevitably increases defect levels. The speaker described a Bi-based ceramic with a tailored thermal expansion coefficient, whereby he intentionally generates multiple polymorphic Bi2O3 phases to provide the goal. The effect of the introduction of multiple non-glass phases on the defect levels is not discussed. Speaker was asked about humidity problems in his system - replied that there isn’t one. Ungya Paik (Hanyang University, Korea) Nanoparticle Engineering for Next Generation Chemical Mechanical Planarization in ULSI Process Described a Chemical Mechanical Planarization (CMP) whereby a chemical attack makes a surface softer and therefore more susceptible to mechanical processing – a corrosive colloidal system may be used. Conventional grinding mechanisms may fail in ULSI device fabrication due to the introduction of scratches, and topography on the surface due to the different hardness / toughness of the materials used. Flatness requirements must be better than 65 microns. Care must be taken to avoid delamination and other interfacial failures using CMP due to the corrosive nature of the chemicals used. In ULSI fabrication, it is necessary to provide selective material removal. In this paper, polymers (containing methyl, vinyl or amine groups) are also used to cohere to various surfaces to increase the grinding selectivity between poly-Si and oxide to 30:1. After grinding, it must be straightforward to remove the polymer. In addition to

9

Si / SiO2 there are a number of materials for which selectivity is required, such as Cu, noble metals and low-k (insulators) materials. Roadmap The resultant processed surface must have low levels of scratching, flatness better than 4.4 Å, and a low concentration of polishing material. By 2015, transistors will have 8 nm features.

ENERGY ENERGY I Katsutoshi Komeya (Yokohama National University, Japan) Silicon Nitride Ceramics for Bearing Applications, Background and Progress, The benefits of silicon nitride and sialon ceramics for wear resisting applications were outlined highlighting the importance of microstructure on properties for engineering applications. Key innovations included the use of sintering aids such as Y2O3-Al2O3 in the 1980’s then Y2O3-Al2O3 with TiO2 and AlN. The AlN lowers the sintering temperature and the TiO2 reacts with nitrides to form nanodispersed TiN in situ which improve wear behaviour significantly. More recent development of seeded structures to control texture and carbon nanotube (CNT) – silicon nitride composites was emphasised. CNT’s improve wear and increase electrical conductivity reducing dust adsorption by static electricity. A timeline of applications from diesel engine glow plugs in the 1960’s through hot chambers, turbocharger rotors, cutting tools, jigs for Al die casting, Milling media, heaters and engine wear parts, was presented. Problems to solve include even dispersion of TiN nanoparticles, densification of CNT composite systems, development of more reliable composites, reduction in cost. Potential future applications include hybrid ceramics with multifunctions, as cricket ball sized bearings in next generation wind turbines and in aerospace. Keith A. Blakely (NanoDynamics Inc., USA) Ceramic Revolution May Yet Arrive – Ushered in by Nanotechnology,

The chequered history of the promise of ceramics was outlined: ceramic heat engines and turbocharger rotors for automotive, high Tc superconductors for energy transmission, ceramic matrix composites for sporting goods, armour, electronic packaging and heat exchangers and the Lanxide process. Nanoscale powders including clays, carbon black and fumed silica are well known to ceramists and nanoplanar structures such as multi layer ceramics in capacitors and packages also well developed. Major challenges remain however in affordable and renewal energy and clean water. In Energy, nanoscale ceramics will impact in: energy production in fuel cells, thermoelectrics and photovoltaics; in energy storage in batteries, ultracapacitors and hydrogen separation and storage; and in energy transmission and conservation in high

10

Tc superconductors, catalysts, thermal fluids and photonics. In the last 5 years specific geometries of Solid Oxide Fuel Cells (SOFC’s) have started to be economically competitive e.g. microtubular SOFC’s based on nanotechnology. In photovoltaics nanomaterials are impacting in Si-based and flexible substrates (high volume production techniques) and in quantum dot sensitised cells. Nanostructured core-shell thermoelectric materials such as PbTe-PbSe hold promise for conversion of industrial waste heat to electricity. Potential applications include car cooling systems, fridges and supplemental industrial power generation. Advanced storage systems evolving based on Li ion batteries and Sn-doped CNT’s and ultracapacitors based on nano thick layers of dielectrics and conductors may store electricity generated by wind and solar means. In Water are developing filtration membranes and systems for remediation based on chemical sorption and photocatalysis. As we go lower in the water table the water is less pure. Direct opportunities include use of nanoporous filters and membranes, low pressure membranes for desalination, monitoring devices (water level and purity) and remediation by containment-specific treatments. Indirect opportunities include microclimate control via nanoenhanced fertilisers and reflective coatings to reduce evaporation; antimicrobials and photocatalysts for biofilm reduction in filters, dry laundry processes and photocatalytic and hydrophobic (always clean) surfaces. ENERGY II The focus of this session was on superconducting materials. J. Daley (US DOE) Ductile Ceramics that Carry High Electric Current The focus of this presentation on ductile ceramics was concerned with superconducting wires with the aim of the work being the production of a high temperature superconducting wire with 100 times the capacity of conventional Cu wires. A secondary aim of developing electric power equipment that is half the size of conventional power equipment was also identified. The materials of interest were identified as those of the common superconductors (Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O) which undergo a superconducting transition at 92 K and 110 K respectively. In terms of the development of the wires the discussion started with an outline of the status of 2nd generation wires that are produced by thin film deposition techniques and epitaxial growth. These materials have higher performance in magnetic fields and a lower cost. However many challenges remain including grain misorientation, grain boundaries, anisotropy and mechanical properties of the films. For the 2nd generation wires several goals were identified: 300 A/1 cm wide/100m by 2006, 200 A/4mm wide/100m/3T/65K by 2008 and 1000 A /1000m/0T/77K by 2010. A property variation of less than 5% over the length of the wire was also included. Whilst optimisation of the electrical performance was highlighted the strength and ductility of the wires was also identified as a focus. Two main architectures for the superconducting wires were discussed. The first is a multilayer structure proposed by Los Alamos laboratory which uses both PLD and e-beam evaporation. The second

11

architecture was proposed by Oak Ridge laboratory and is again a multilayer structure but using MOCVD rather than PLD. Considerable progress has been made by both groups with Los Alamos working with SuperPower and Oak Ridge working with AmericaSuper. The Los Alamos Ion Beam Assisted Deposition (IBAD) design has achieved a wire of 104A and 97m in 2005 and 219A and 322m in 2006. Oak ridge, using a Rolling Assisted Biaxially Textured Substrate (RABITS), achieved wires of 186 A and 34m in 2005 and 160A and 85m in 2006. Each group aims to get a wire of length 1km. D.E. Petersen, (Los Alamos National Laboratory) High Temperature Superconducting Tapes, Ceramic processing In this presentation the author claimed that superconductivity was a key technology for the 21st Century. Currently there are greater than 100,000km/yr of superconductors produced at a cost of $3/kA.m generally using liquid helium technology and used in MRI, maglev trains etc. For higher temperature superconductors one of the main issues is the deposition of the multilayer structures required for wire production. There are two main competing technologies: IBAD and RABITS. In each case one of the issues is the substrate used – currently Ni with an Al2O3 barrier layers is the best option. However, this introduces extra layers and hence complexity to the design. Thus one of the main challenges is the reduction of the number of layers in the structure. It was also highlighted that the deposition temperature of the layers can affect the critical current achieved by a factor of 3. There is also a thickness dependence of the current density and one of the possibilities is to use a CeO2 barrier layer. A further two main challenges were outlined – the first being the improvement of the magnetic flux pinning of the films and identifying differences in the films deposited by different technologies with the second being to bridge the gap between processing and commercialisation. In summary three main technical barriers to the development of high temperature superconductors were identified. These were the chemistry, physics and power engineering. Chemistry is concerned with the control of the film deposition, physics with the optimisation of the superconducting properties and power engineering with the production of coils, cables and devices. ENERGY III Pavadee Aungkavattana (National Science and Development Agency, Thailand) Solid oxide fuel cells: The future of power generation The speaker gave an overview of the advantages of fuel cell technologies over conventional fossil fuel power generation, which are:

1. A theoretical maximum efficiency of 85 % cf. < 50% for conventional means 2. Near zero emissions 3. No moving parts

12

4. Quiet The fuel cells work by oxygen diffusion through a solid electrolyte, for example a modified zirconia. This can only be achieved using temperatures between 600 and 1000 °C, which leads to serious engineering and safety considerations in order to prevent charge leakage and explosion. The speaker reported on a large review of academic and industrial bodies, on what are the most important drivers in fuel cell technology. Of these it was felt that political drivers were the most important, mainly energy diversity. I was surprised to find that it was considered that such drivers were more important that environmental drivers, such as Kyoto protocol. Roadmap The speaker proposed enormous markets for fuel cell technology. The US has committed $1.7 B over the next 5 years, and by 2011, it was suggested that the global demand would reach $46 B p.a. Predicted that by 2050, hydrogen based fuel cells be predominant energy source. The questions related to verification of the drivers, and that materials issues relating to the electrolyte were the largest hurdle. Martin Stelter (Fraunhoffer IKTS, Germany) Ceramic materials and systems for the commercialisation of SOFC fuel cells The speaker gave an overview of fuel cells plus the system surrounding it and the materials involved. In addition to the fuel cell, a vapouriser and reformer is used to generate a H2 rich gas from the fuel. The speaker also discussed the processing and materials issues of the fuel cell system, and the importance in maintaining a coalition between porosity, the electronic conductor (Ni) and the oxygen conductor (stabilised zirconia) in order to generate high power densities. Also, it was discussed that the most active materials are not necessarily the most mechanically sound, especially with high porosity levels. The most important engineering advances in the future were described to be:

1. Higher tolerances. Variations in area, size of individual cells in a stack lead to variation in voltage output.

2. Higher power densities required 3. Externally supported structures 4. Single cell failures can lead to failure of entire stacks – generate solutions 5. Match thermal expansion mismatch of various materials 6. More robust sealing solutions

Roadmap Required costs need to be 1000 – 2000 Euro / kW to compete with other solutions Large improvements can be made with existing materials using engineering solutions

13

The only question was why did the speaker think that planar cells were the way forward – the speaker considered that in the long term, the cost would be the lowest as it is compatible with other fabrication technologies. David Richerson (Richerson and Associates, USA) Fuel Cells: Has their time finally come? The speaker discussed requirement for fuel cells driven by increasing yearly energy demand, with a number of stunning examples: Primitive man requires 8 MJ / day – modern US citizen 96 MJ of which 26 MJ transportation The developing nations share of global consumption: 23% in 1996 and 43% by 2020. Since 1950, US energy consumption has tripled. 1 in 2 people in US have car; only 1 in 640 in China at present. Requirements from fuel cells comes about from (a) requirement for more distributed and therefore reliable energy, and (b) efficiency.

Method Efficiency / % Coal fired power station 30-33

Car 28-35 Fuel cell 40-70

Fuel cell with waste heat collection 80-85 If fuel cell used in car, can achieve 79-97 mpg using petrol, and 101-128 mpg using H2. Roadmap Speaker suggested that two biggest problems were cost and durability. Speaker also suggested that a roadmap was unsuitable as five year roadmap set five years ago was a long way off realisation at present. The speaker outlined that fuel cells over the next couple of decade would provide a huge challenge for the ceramics industry – far more than just the electrolyte. ENERGY IV John Marra (Savannah River National Lab., USA) Role of Ceramics in a Resurgent Nuclear Industry, World energy demand is expected to double by 2050. Given the potential of nuclear power to provide energy without greenhouse gas production a substantial new build programme is envisaged. Ceramics can influence how these facilities are designed, constructed and operated via their impact on safety, waste disposal and proliferation resistance. Glass, cements and ceramics are key enablers with major applications in fuel and target materials and waste forms. Roadmap Markers (near term):

• Within the next year significant advances in use of Mixed Oxide (MOX) Fuel, which uses Pu left over from military programmes, and development of Inert Matrix Fuels (IMF’s), which incorporate Pu into e.g. ZrO2 matrices and

14

burn the Pu, will be made. These have inherent proliferation resistance which is key to peaceful application of nuclear power. In reactor testing of promising compositions is planned or underway.

• Significant progress will be made to address difficult legacy waste materials from both weapons production and civilian nuclear power applications. Legacy facilities will be decontaminated and decommissioned at an increasing rate. To safely and efficiently accomplish this closure, advances are needed to make current waste stable using simple, cheaper and transportable processes – bring remediation to the waste.

Roadmap Markers (mid term):

• Nuclear renaissance will hit full stride. Several new reactor projects will be underway within the USA and dozens underway in developing economic markets (notably India and China). IMF’s will come to the forefront of materials research to support nuclear power in stage-wise development via initial deployment in light water reactors and subsequent deployment in advanced fast and burner reactors.

• Advancements in waste stabilisation processes will focus largely on increasing waste loading in HJW forms. This will involve improved efficiency of facilities (i.e. increased production) and attempts to minimise the volume of material slated for geological repository.

Roadmap Markers (long term):

• Significant advancements in advanced reactor (both fission and fusion) technology. This will include further fuel form developments for Generation IV reactors and solving high temperature materials problems for the ITER fusion reactor project in Cadarache France.

• Demonstration of advanced nuclear fuel reprocessing flowsheets to generate limited liquid effluent.

G Sundararajan (International Advanced Research Centre for Powder Metallurgy and New Materials, Hyderabad, India) Hidden Ceramics in Energy and Transport Systems: Current Status and Roadmap for the Future Hidden, as hidden from the publics view, but performing important functions. Ceramics important in Energy generation (photovoltaics, nuclear, wind etc.), storage (rechargeable batteries, supercapacitors) and saving (thermal barrier coatings [TBCs] etc). Ceramics important in Transport in automobile (catalytic converters, engines and power train, sensors etc), railways, marine and aerospace. Energy materials discussed included thermoelectric materials, structural ceramics, supercapacitors, superconductors, SOFC ceramics and Li ion batteries. In SOFC’s mentioned developing glass and glass ceramic cathode seals, ZrO2 based and Ba/Sr pyrochlore electrolytes, CuO2/CeO2/YSZ anodes and stack design options using microtubes, thin film electrolytes and honeycomb configurations. Use of ceria nanocomposites was envisaged. In thermoelectrics mentioned Bi-Te compounds, Pb-Te, Si-Ge and Co-Sb but toxicity problem so also looking at complex oxides and metal borides, boron carbides. Expect nanocomposites and nanoscale oxide ceramics to be important. In TBC’s nanolayered refractory oxides being examined e.g. BaNd2Ti3O10, systems will also become multifunctional with e.g. sensing aspect. In Li

15

ion batteries problems as LiCoO2 is expensive and toxic. Spinels are being examined and nanomaterials hold promise including Li/Ti oxides and ordered LiNiMn oxides.In supercapacitor systems use C-based electrodes with RuO2 and IrO2 metal oxides and conducting polymers.

ENVIRONMENT ENVIRONMENT I W. Kelly (Unifrax Corporation, USA) Product stewardship: Another Tool for Driving Business Excellence The first presentation of this session was given by the Chairman and Past President of Unifrax and concerned the products produced by Unifrax and also of product stewardship in general. As background the talk introduced the company and its products, being mainly high temperature insulating fibres and refractory ceramic fibres (RCF). Many adverse impacts of the production and use of these products were highlighted, such as the well known health hazards associated with asbestos. The main thesis of the talk was that a risk free society is unattainable and therefore it is desirable to identify and manage risk. It is in this framework that product stewardship was discussed, being defined loosely as greener design and waste minimisation. To achieve this Dr Kelly proposed that responsible management practices had to be applied at every stage of the life cycle of a product to minimise all forms or risk. This is counter to the conventional viewpoint in which the responsibility for a product passed from the producer to the consumer. To enable this alternative to be introduced the company had to engage with representatives from a number of sectors including government, unions, industry and NGOs. An example of the RCF product stream was used to illustrate the challenges that had to be addressed. Due to the classification of RCF as a possible carcinogen in 1987 significant health monitoring programmes were implemented and extensive consultation with employees, customers and regulatory bodies undertaken. This directly led to the Product Stewardship Programme (PSP) from which several key lessons were learned, e.g. top management input was essential. Fourteen key lessons were outline along with unexpected benefits to the company such as improved employee morale and closer ties to government. Dan Perera (ANSTO Australia) Geopolymers: Low Energy and Environmentally Sound This presentation focussed on inorganic polymers with structures similar to Portland cement. An initial overview of what a geopolymer is and how they are produced was given, including the use of fly ash, a waste product, which involves calcinations of materials at temperatures of ~750oC. Once calcined these materials can be cast and cured. The work described focussed on some fundamental studies of the materials. An initial result of in-situ heating and TEM of metakaolinite at temperatures up to 500oC indicated that nanoparticles were formed that were amorphous, with no crystallisation

16

of heating. Further discussion was directed at the physical properties of the geopolymers and the potential for the dissolution of tri-and tetra-valent ions within the polymer, forming poly(sialate-siloxo) species in which tetrahedra of Si4+ and Al3+ coexist. Solid state NMR was discussed as a method to investigate the structure of these X-ray amorphous materials, enabling local coordination information to be gleaned. This was also combined with XANES studies. The possibility of immobilising 137Cs and 90Sr in these materials was also discussed. A more extensive discussion of what defines a geopolymer then followed: four main criteria were identified i) inorganic, ii) polymerisable iii) sets like an organic resin and iv) develops strength faster than ordinary Portland cement (OPC). Several advantages were highlighted such as the applicability of ordinary concreting techniques to these materials and the ability to produce steel reinforced structures. Roadmap milestones: Impact within one year:

Building products with acid and fire resistance. Impact within 1 – 5 years: Immobilisation of low/intermediate level waste (Cs, Sr)

Reduction of CO2 production through use of geopolymers in concrete production

Refractory castables Impact within 5 – 10 years: Potential biomaterials for bone replacement Nanoporous materials Replacement of OPC in buildings ENVIRONMENT II. SW Lee (Sun Moon University, South Korea) Development and Commercialisation of Photocatalysts 90% of commercial photocatalysts are TiO2 which has a 3.2eV bandgap so that when exposed to UV light with wavelength less than 380nm it produces electron/hole pairs with the electron reacting with oxygen to produce radicles. Historically, photocatalysis was a problem for paint manufacturers who tried to suppress it as it led to oxidative degradation of the polymer resins used. In 1970 Fujishiu produced hydrogen from water using a titania electrode leading to understanding of the photocatalytic effect. Developed in the early 1980’s for air cleaning (removal of NOx), water purification and self cleaning anti-bacterial surfaces. Most of the current market is in Japan but is spreading rapidly. Three case studies of commercialisation were described:

• Self cleaning TiO2 surfaces. UV light interacting with TiO2 kills bacteria. Photo induced wettability arises as the hole reacts with lattice oxygen forming vacancies which bond to surface OH groups causing a hydrophilic state.

17

• Ti HAP (Ti hydroxyapatite) photocatalyst overcomes some problems of TiO2 which has high refractive index, low adsorption capacity and is unsuitable for use on hydrophobic materials. TiHAP does not degrade polymer resins and so is good in paints and has potential in dental applications. It is not a semiconductor so the mechanism of photocatalysis is unclear.

• Plasma Crystallisation Processing. Thin film deposition by sputtering on different ceramic substrates and can crystallise at low temperature (40oC).

WE Lee (Imperial College London, UK) Current and Potential Contribution of Ceramic Technology to Achieving Sustainable Development, The present high level of waste production and limited recycling was described along with types of solid, liquid and gaseous hazardous and radioactive wastes. The ability of the ceramics industry to not only generate but also reuse and recycle high volumes of oxide/silicate waste was highlighted. Current reuse of wastes in cements and glasses and potential for reuse in other high volume vitreous ceramics and refractories was mentioned. A toolbox of wasteforms for waste immobilisation is under development including polycrystalline ceramics, cements, glasses and glass composite materials (including glass ceramics derived from waste). Difficult radioactive wastes such as graphite, pertechnatate and iodine still need wasteform development. Other radwaste opportunities include the need for multiscale modelling, life cycle analysis and more multipartner international collaborations on the lines of the Generation IV future fission and the ITER (international tokamak experimental reactor) fusion programmes.

Roadmap Markers 1-5 years: • Increased legislation to drive reuse and recycling of waste and immobilisation

of hazardous and radioactive wastes. • Increased inventory and public desire for products made from “secondary

materials” especially in construction and high volume ceramics. • Cementation. Room temperature ceramics (e.g. geopolymers). Carbon

negative cement systems. Mobile facilities. • Vitrification for hazardous and difficult HLW radwastes. Cold crucibles,

plasma technologies. Mobile facilities. • In nuclear industry. Use of Pu in Mixed Oxide (MOX) and Inert Matrix fuel’s.

Use of ceramic wasteforms for immobilising Pu and I. • Reduced reliance on heavy metals especially in electroceramics. Roadmap Markers 5-10 years: • Increased globalisation of research into and implementation of sustainable

development. • International research programmes (ITER, EC, Gen IV, GNEP). • Start of construction of radwaste repositories. • Application of particulate nanotechnology to environmental clean up (e.g.

SAMMS) Evolution of multiwaste recycling centres with ability to convert to useful materials on site (incineration, separation and sorting, vitrification, cementation etc.).

18

T. Watanabe (University of Tokyo, Japan) Photocatalyst Materials for Environmental Protection: Science, Technology and Market Road Mapping,

While TiO2 dominates other photocatalysts include CdS, SnO2, WO3, SiO2 and ZnO. Have many applications including self cleaning surfaces (decomposition of oily dust), air cleaning (decomposition of aldehyde, NOx removal), water purification (decomposition of organics), bactericidal (kill bacteria and virus e.g. MRSA), deoderising and self sterilising. Used in paints, in air filters, keeping lights clean in tunnels, agriculture/hydroponics, decomposing pesticide residues, Pilkington ActivTM self cleaning glass. TiO2 powder and coatings used to degrade organic and inorganic pollutants in water as well as toxic gas. For high surface area use nanoparticles or sol gel or plasma sprayed coatings. Anatase best polymorph for photocatalysis. If redox potential of substance is less than or greater than that of TiO2 it is oxidised or reduced in UV light. Enhance photocatalytic behaviour by TiO2 grain size, doping with noble metals (Fe3+, Ru3+, Cr3+) and composites CdS/TiO2, ZnO/TiO2, PbS/TiO2 etc. Roadmap Markers 1-5 years:

• ISO standards for water purification, deodorising activity, light sources. Roadmap Markers 5-15 years:

• Enhanced photoreactivity. • New low cost materials (TaN, perovskites). • Visible light photocatalysts (TiON, TiOF, TiOFN but currently too

expensive).

GLASS AND OPTICAL MATERIALS GLASS AND OPTICAL MATERIALS I D. L. Morse (Corning Inc., USA ) Advances in Technical Glasses

Corning has a long “history of innovation”, stretching back to 1908, when its first laboratory was established. The development of Pyrex glass in 1929, the ribbon machine for light bulb manufacture, the updraw process, high temperature aluminosilicate glasses in the 1930’s and a host of other innovations have been attributed to Corning over the past century. More recent developments have included dental ceramics and diesel particulate filters in the 1980’s, and continued development and improvement of optical fibres and display technologies since the 1990’s.

In this presentation the evolution of display technology was charted from cathode ray tubes through the development of active matrix liquid crystal diodes in the late 1960’s, to organic l.e.d.’s in more recent times. These materials require no backlight, are faster, thinner, give wider viewing angles and require less electrical current than their predecessors. However, their costs are currently high as may be expected for a newer technology. Display technology and digital light projection are fields which will continue to grow in the future.

Corning has developed glasses for CRT applications; their glass fusion process allows the production of glasses for l.c.d and l.e.d substrates. Next-generation substrate glasses are currently under development, a recent launch being Eagle XG

19

(2006). Corning now has the ability to produce a sheet of this material in sizes larger than a person. Eagle XG is free of As and Sb, which are environmentally damaging. In the speaker’s opinion, future technologies include:

• Display technologies: image capture and displays for cellphones, and image projection rather than conventional displays.

• Forecast rapid growth in l.c.d / l.e.d market • Large plasma displays • L.c.d for televisions, desktops, cameras • Polymeric l.e.d. devices • Rear-and-front image projection • Flexible displays – thin glass / waveguides? • Wearable displays, pocket PC’s and virtual reality devices • Transparent organic l.e.d. (OLED) devices.

The author was asked by the Roadmap co-ordinator to list the 3 most important ceramic developments which would be required to meet these future challenges:

1) Polysilicon substrates – high probability of success 2) OLED sealing materials – this is applied research, strong chance of success 3) Silicon-on-glass, still under development but with good chance of success

H. Arribart (Saint-Gobain, France) Basic research that will benefit the glass industry

This presentation took the form of a review of the current state of glass science and questions which remain unanswered, concluding with a discussion of academic / industrial collaboration. Neutron and x-ray diffraction techniques, coupled with numerical simulation methods, have provided great improvements in glass science; in understanding of structure and cation environments, surfaces, glass transition, plastic deformation and the physics of glass fracture. Unusual coordination numbers, such as [5]Ni, have been documented, and glasses for solar control have been developed, for example by replacing Mg by Ca in soda-lime-silica glasses and utilising the effects on absorption peak wavelengths and iron coordination. Understanding of cations as modifiers or charge compensators has also improved, for example Li2O in Li2O-SiO2-Al2O3 glasses. A key comment made by this speaker was that this type of fundamental research and the knowledge which it provides is essential for the design of new glasses and to take glass technology forwards.

Controversy and discussion still exists on cation ordering in glasses, for example heterogeneities on scales of 1-3 nm. Are we dealing with polynanocrystalline structures or not? We are still unable to answer these questions with confidence. Recent theories such as Greaves’ modified random network theory could perhaps be used to study ionic conduction and aqueous corrosion mechanisms. There has been good recent progress in surface studies – adhesion, surface functionality, using techniques such as AFM and numerical simulation.

The speaker outlined 5 “questions for the future” as follows: • Accelerated melting and fining. Reaction kinetics, improved mixing and

develop new fining chemistry and technologies • Homogeneity. How to measure it? A reference “equilibrium” structure needs

to be established. Improved statistical methods are needed, as is improved correlation of inhomogeneity with properties.

• How to screen unexplored glass compositional domains? The use of combinational chemical methods was suggested.

20

• Nanoparticles to improve toughness, either by in-situ precipitation or by use of nanopowders – which is best?

• Prediction of structural evolution below Tg. During the question & answer session the following issues were noted:

• The need for greater collaboration was stressed • Must emphasise compositional dependency of heterogeneity / homogeneity • We cannot yet say to what scale structural sensitivity reaches • Polishing mechanisms are not yet understood and should be on the Roadmap • Batch modification has not received sufficient consideration. Academic / industrial collaborations in France has led to work on glass-polymer

adhesion, inorganic films, subcritical flaw analysis, fracture of heterogeneous media, surface mechanics and the plasticity of glass. Participation with other French glassmakers and academic institutions has provided a link between all French labs working on glass, providing conferences, summer schools etc. Global collaborations are also sought.

The author was asked by the Roadmap co-ordinator to list the 3 most important developments required to move glass technology forward:

1) Glass toughness 2) Homogeneity 3) Glass chemistry

I. A. Aksay (Princeton Univ., USA) Biologically Inspired Ceramics This presentation began with the question – why are ceramics not used for boats, planes, etc, if they are so strong? One answer is because they are too dense. The speaker went on to observe that biological materials are far less dense than ceramics, with a lower percentage of ceramic material, but the key difference is the work of fracture in biological materials. As an example the structure of enamel was considered – layers of calcium phosphate over a nanocomposite, porous outer shell Sea urchins and pearl possess laminated, tabular structures, with “healing adhesives” holding the layers together. It was noted that the best form of mechanical testing of such materials is the bend test, tensile type I, and tests which provide homogeneous stretching of the whole sample rather than local stretching. So how do we make these kinds of very strong, lightweight, self-healing materials? We need to follow the same assembly mechanism as nature uses. Self-assembly is the key to this, however to date we have only been able to make it work on the nanometre scale. The future challenge is to increase the scale, one possible method being electric-field restructuring. Application could include optical waveguides, ultra-light weight aerogel materials, 3-D optical storage media, and water vapour accumulation.

The speaker was asked by the Roadmap co-ordinator to list the most important developments in this field for the next 10 years:

• Self-assembly, particularly its’ practical, “nuts & bolts” aspects and the need to move to larger scales.

• The speaker also commented that he did not feel that the American Ceramic Society was moving in quite the correct direction, and that the ceramics community needs to reach out to other interested or related research disciplines more effectively. A suggestion was made to change academic curricula in order for the ceramics community to help achieve this.

21

GLASS and OPTICAL MATERIALS II C. R. Kurkjian (Rutgers University, USA) Use of early “maps” to guide us along the road to a stronger glass of the future

Griffith was the “father” of modern strength research in glasses, working at RAE Farnborough in the 1920’s. He was followed by workers including Otto (1955) Cameron (1962) and Lower / Mazur (2005). It is critical to understand the fundamentals of composition / strength relations. Indent testing has had many years of use, beginning in 1921, through the 1960’s and 1970’s when workers such as Shand and Baikova demonstrated that damage patterns of SiO2 and SiO2-Na2O-CaO (SLS) glasses were dissimilar. The brittleness index varies substantially with composition and density.

• Cracking of SiO2 glass is much more complex than SLS glass. Why? The answer is not yet known. Newer techniques such as AFM are being used to study this behaviour. This is currently hot topic and will, in the speaker’s opinion, continue to attract research interest in the future.

• However, throughout the history of strength and indentation of glasses, there have been a number of significant time delays between steps forward – between ideas and their implementation. What are their reasons? A lack of concentrated effort on glass strength studies. Mechanical properties of glass require a more concerted effort by the scientific community. Comments regarding the Roadmap were that there has never been enough sustained effort in this field. Scientists know what must be done, but not necessarily how best to go about doing it. Collaborations have been past successes, and more effort must be put into forming new collaborations.

J. Brown (GMIC, USA) Glass: introducing our society to a new material age; clues to aid glass in approaching full strength

The only quality of glass, which has remained relatively unchanged throughout its historical development, is its strength (or lack thereof), i.e. its brittle nature. Commercial soda-lime-silica glasses typically attain 0.005% of their theoretical strength. The strength of glass, and how to increase it, therefore remains one of the key issues facing glass researchers. Glass strength has been repeatedly demonstrated to depend primarily on surface condition. The speaker gave details of a recent student competition, the object of which was to increase glass strength by 50 times. This produced several positive outcomes, and the drive for this kind of practical interaction with the researchers of tomorrow produces clear benefits. A new competition was also announced.

Developments in glass formation were discussed briefly, including low temperature glass processing, for example sol-gel glasses. However, the need for a fully transparent material with no residual porosity means that further investigations are required for low temperature glass formation and properties. Developments utilising polymers and glass together may present further opportunities in the future, despite the fact that this technology has been developing for many years. The fundamental requirement for improved strength of glass remains central to its continuing development: possible mechanisms of achieving this include alternative glass formation mechanisms such as sol-gel, and also the utilisation of coatings, for

22

example polymeric coatings, to protect the vulnerable glass surface. Opportunities for the future therefore include research at boundaries with other materials, to produce what are essentially hybrid material, such as glass composites. H. Schaeffer (International Commission on Glass, Germany) Challenges and future of glass melting technology

Utilisation of energy in glassmaking is now of critical importance to the survival and evolution of the glass industry. Detailed information is required to enable reliable process management. This includes glass property information, for example viscosity, optical properties. “Hidden” parameters such as redox, OH content and cullet utilisation are all of critical importance. Foreign cullet recycling has an overall rate of 63% at this time. However its quality in terms of chemical composition and impurities is crucial. One example of an early mistake causing problems through years of recycling is heavy metals. Early recycled glass contained high levels of toxic components, particularly Pb originating from lead crystal glass. Detection and separation technology is required to remove ferrous and non-ferrous metals, ceramics and glass-ceramics, organics and other glass types, such as borosilicates, ovenware, and lead crystal. Combustion issues remain of paramount importance to glassmakers – for example gas solubilities and fuel types. In-situ sensors for glass melting are now becoming more widely used. These include online and ultrasonic measurements of factors such as gas composition of the furnace atmosphere, and for use in optimising combustion efficiency. Problems, however, arise in separating thermal and compositional effects in some cases. Emission spectroscopy and voltammetry can also provide useful on-line process information.

• Current and future requirements are for more sensors and better process control. This should lead to better efficiency and reduced environmental impact. Modelling and process automation can aid in solving these and other problems and, in the speaker’s opinion, should be involved in future research and development efforts.

• During the question & answer session, the issue of addressing environmental concerns by making batch and glass alterations to reduce emissions and lower glass viscosity was raised. To the disappointment of this observer, and, it subsequently emerged, others who were present, this suggestion received little discussion, support or affirmation during the Q&A session, and it appeared unlikely that this area of research will appear on the Roadmap.

GLASS AND OPTICAL MATERIALS III R. Clasen (Saarland University, Germany) E-Field Enhanced Processes for the Preparation of Nanomaterials A purely technical presentation that reviewed work in his own laboratory on making nanostructured ceramics. Starting with flame hydrolysed powders (primarily SiO2 produced by Degussa), the underpinning theme was the use of electric fields, for example, electro spraying and electrophoresis deposition as green forming routes through to microwave and SPS sintering. The bulk of the presentation focuses on the EPD work, including the production of dental crowns (in ≤ 1 minute).

23

M.R. Pascucci (Cera Nova Corp., USA) Transparent Polycrystalline Ceramics There is a wide range of applications for transparent ceramics, including laser hosts, scintillators, advanced lighting, transparent armour, infrared windows and domes and electro-optic devices. What is required is better performance (mechanically and optically) at lower cost (e.g. via faster and near net shape processing). The main focus is on cubic ceramics (AlON, spinel, Y2O3, MgO etc.) but Al2O3 can also be reasonably transparent if processed correctly. Transparency can generally be achieved via having very large grain sizes or very fine grain sizes (≤ 0.3 µm); the focus is on the latter to achieve superior mechanical performance. Transparent armour was identified as potentially the largest market; requirements are transparency in the visible spectrum and good ballistic performance. Alumina is a major focus although spinel and AlON are also ballistically good. These materials offer weight savings (improving fuel efficiency) though at the expense of higher initial costs. Large and curved windows are a challenge as is multi-hit capability. A 100% α = Al2O3 nanopowder is a necessity. Infra-red transparent windows are largely focussed on single crystal sapphire (expensive), AlON, spinel and Y2O3 – the latter having the widest wavelength window (3-8 µm). The biggest market is sensor protection for aggressive environments. Challenges include near net-shape forming, densification with minimal grain growth and improved surface finishing.

MULTIPLE APPLICATIONS MULTIPLE APPLICATIONS I Teruo Kishi (National Institute of Materials Science, Japan) Fine Ceramics R & D – Roadmaps in Japan and Strategies at NIMS J-B Li (Tsinghua University China) Advanced Materials R & D in China Julie Yeomans (University of Surrey UK) UK Structural Ceramics Network DW Freitag (Bayside Materials Technology, USA) US Advanced Ceramic’s Industry Roadmaps and Initiatives The four talks in this session covered current activities in Japan, China, the UK and the USA, with little input directly relevant to the roadmapping exercise. The Japanese presentation was concerned with the activities in the National Institute for Materials Science and in particular the projects underway in the area of nanotechnology (novel nanotubes and nanosheets, nano-scale semiconductor devices, nanostructured materials for fuel cells etc.). Likewise the Chinese presentation focussed on research in nanotechnology (nanospinels for water electrolysis) against a background of increased ‘urbanisation’, the social pressure created by 20 million people looking for employment each year and a culture that viewed ceramics as art objects. The presentation on the UK’s structural ceramic network (SCERN) outlined the approach to roadmapping that is being taken. The final presentation was an update on the ‘Advanced Ceramics Technology Roadmap’ that was produced by American government/industry (i.e. with virtually no input from the academic community) in 1999 and was updated in 2004, concentrating on manufacturing requirements The drivers for change were identified as:

• Unrealised market expectations (ceramic matrix composites)

24

• Threats (ceramic armour) • Rising cost of petroleum-based goods • Aging infrastructure • Growing and aging population

Cross-cutting areas requiring attention were:

• Databases (standardisation) • Design and life prediction • Non-destructive evaluation • Optimisation of fabrication • Need to produce demonstrator components

MULTIPLE APPLICATIONS II A.P. Katz (Air Force Research Laboratory, USA) Ceramic Matrix Composites: Opportunities and Challenges The USAF wants to be able to go anywhere, any time, fast and cope with any threat when they get there. As a result the AFRL deal with all types of materials, including their manufacture. Katz’s group deals mainly with structural ceramics; they have 18 people and a budget of $11m per year of which 75% is spent outside the AFRL. With respect to CMCs, they want materials with the toughness and density of aluminium but capable of withstanding 1350+°C for up to 30,000 hours. They are focusing particularly on turbine engines (e.g. to reduce cooling air requirements by 20%); hot exhaust structures (to achieve up to x4 longer operational life); brakes and clutches (to reduce mass and achieve performance stability with respect to temperature and moisture) and space applications, e.g. liquid rocket engine nozzles (40% less mass) and thermal protection tiles (4 x impact resistance). A particularly powerful driver currently is reducing fuel costs; the Dept. of Defence spent $4.7b in 2004, rising to $7.4b in 2005. The USAF dominates this expenditure. So lightweight aerostructures are a high priority. The wish list put forward included: cheaper materials; greater reliability; better design approaches (specifically based on ceramics and CMCs); improved modelling and lifing and better NDE. It was indicated that the US is moving away from an isolationist stance and Katz’s group is pro-actively looking for collaboration with overseas universities, industries and Government labs. They have existing links with the UK and other countries. Seed funding is available for projects, US$10-30k typical, $50k occasionally. R.B. Cass (Advanced Cerametrics inc., USA) Innovative Products and Processes based on Ceramic Fibre Forming Technology A fascinating paper on the use of piezoelectric active fibre composites for harvesting energy from ambient sources of vibration. ACI have produced flexible (can be bent in a complete circle), sintered fibres from PZT. These are already finding applications in helicopter blades, tennis rackets, skis and snowboards amongst others where they act to dampen vibrations. However, they are now also being developed for ‘energy harvesting’. Essentially, power can be extracted from the fibres as piezoelectric elements as a result of vibrations; this holds out the potential for the elimination of batteries. Examples quoted include mobile phones that are powered simply by being carried; sensor nets (e.g. for defence, transport etc.) that do not need connecting to a mains supply or having requirements with respect to battery

25

replacements. Devices that can be left and will operate indefinitely without maintenance. These vibration-based ‘power supplies’ are 70% transducer efficient and cheap, $10 was quoted for a current system. Miniaturisation is underway; a (very low power) system the size of a grain of rice was quoted. L. Saiber (Du-Co Ceramics, USA) Perspective from the Association of American Ceramic Component Manufacturers Formed in 1992, the AACCM currently has 17 companies. The aims of the AACCM are to increase public awareness, direct end-users to the right company and to improve productivity. Meetings are held with guest speakers and consortia put together to get funding for research. The website (www.aaccm.org) contains success stories from the members. The members report growth and increased collaboration as a result of joining the AACCM. The major threats reported included costs, including salaries and benefits. MULTIPLE APPLICATIONS III J Vecchiarelli (United Technologies Research Centre USA) Prospects for Ceramic Technology in United Technologies Corporation UTC and its corporate research centre was reviewed. The global corporation has 7 divisions including Pratt and Whitney (aerospace), Sikorsky (helicopters), UTC Power (fuel cells and microturbines), OTIS (lifts/elevators) and UTC Fire and Security (Chubb and smoke detectors). Products include ceramics for SiC/mullite/BSAS brakes in lifts, armour, heat exchangers and power electronics. Their research program examines nonoxides such as SiC and Si3N4 in structural applications. Both need environmental protection in gas turbines since the presence of water volatilises the protective silica coating resulting in material loss (recession). Environmental Barrier Coatings, EBCs were developed including functionally graded barium strontium aluminosilicates (BSAS) and strontium aluminosilicates (SAS) with NASA and GE in the 1990’s. Applications include gas turbine components (EBC on SiC CMC’s) for higher combustor liner wall temperatures, reduced CO and NOx and improved durability and EBC coated Si3N4 components for auxiliary power units, microturbines for combined heat and power (CHP) systems, and engines for unmanned air vehicles (Albo Hummingbird). Working on ultra high temperature coatings for use on CMC’s such as C/SiC for hypersonic and access-to-space vehicles. Refractory carbides, diborides derived from preceramic polymers and polymer impregnation pyrolysis (PIP) techniques for thermal protection. Also, erosion resistant leading edges for helicopter rotors, and some functional ceramics for SOFC’s and thermoelectrics. K Niihara (Nagaoka University of Technology, Japan) Future Perspectives of Nanocomposites – from Mono to Multifunctionality This was an enormously confusing and badly presented talk which tried to cover far too broad an area. Prof. Niihara found improved wear resistance of SiC/Al2O3 “nanocomposites” in which only the SiC was at the nanoscale in the 1980’s and has since developed the nanocomposites concept to include some functionality with limited success. Many systems were mentioned including: TZP(Ce)/Al2O3 nanocomposites for hip joints, dental crowns and hair cutters; Si3N4/BN for thermal shock resistance and superplastic behaviour; AlN/BN composites for good thermal

26

conductivity. Discussed electrically multifunctional composites such as Si3N4 with ionically conducting glass at the grain boundaries and optically multifunctional systems. A Bellosi (CNR.ISTEC, Italy) Development and Properties of Ultra High Temperature Ceramics Ultra High Temperature Ceramics (UHTC’s) operate at temperatures >1600oC, are self passivating, radiation resistant, heat sink materials that are stable at extreme temperatures in extreme environments are envisaged for applications in aerospace (use in access-to-space vehicles which take off from the planet surface and return through the atmosphere), energy, nuclear, refractories, wear parts, nozzles, armour and electronic devices (heaters). Examples include nitrides, borides, oxides and ternary borides and carbides e.g. ZrB2, ZrC, ZrN, HfB2, HfC, HfN and TaC. Can be fabricated by Electrical Discharge Machining (EDM) due to their high electrical conductivity. A Roadmap for their development was presented from materials selection (guided by thermodynamics) to life cycle optimisation. The main technological barrier is their low sinterability so that pressure assisted sintering is usually needed at temperatures > 2000oC in controlled atmosphere making it difficult to control the microstructure and achieve good properties. Innovative processing is needed include use of sintering aids (e.g. AlN, Ni metal, MoSi2 and Si3N4), new synthesis routes including spark plasma sintering (SPS), self propagating high temperature synthesis (SHS) and reactive hot pressing. Composites are made with reinforcements including SiC, HfC, B4C and MoSi2. With 5-20 vol% MoSi2 can get fully dense composites from ZrB2, HfB2, ZrC and HfC by pressureless sintering while retaining > 500MPa strength at 1800oC. Problems limiting progress include lack of thermodynamic data and phase diagrams > 2500oC, difficulty of making/buying raw powders, property testing above 1500oC is limited. MULTIPLE APPLICATIONS IV Thomas Coyle (University of Toronto) Thermal Plasma Deposition of Ceramic Coatings. Gave an overview of the primary current techniques. With the industrially important DC Air Plasma Torch technique (APS) the splats are typically 150µm in diameter, 1-10µm thick with 2-5% residual porosity. VPS employs a higher splat velocity than APS, but the product contains lower porosity; VPS is good for non-oxides. High Velocity Oxy Fuel (HVOF) givers lower porosity levels; suitable for deposition of Al2O3 and lithium chromate etc. Applications include: zirconia for turbine engines; alumina for electrical insulation, automotive, paper making machinery (Al2O3-TiO2); Co-WC for wear and corrosion resistance; hydoxy-apatite for dental, and hip joint implants. In 2004 the global market for thermal plasma coated products was $5.2B (US market $1.8B per year) growing at 8% per year, largely due to the increased demand for aircraft in Asia.

27

New Developments (i) Cold Spray. Enables dense metal coatings at low temperature; materials

need some ductility (ceramics not ideal as they tend to grit blast the surface); fabrication technology needs high velocity.

(ii) DC arc Guns. Combining three arc guns in a single spray unit to enable high throughput.

(iii) Real Time Diagnosis. Sensors to monitor critical parameters during the spraying process (temperature, velocity, diameter and energy) in real time.

(iv) Numerical Simulation. Incorporation of heat transfer and particle temperature and velocity in the Monte Carlo simulation models yields realistic simulation models of deposition process, including roughness of the final coating.

(v) Refinement of coating by changing the feedstock. Agglomeration of nanoparticles leads to agglomeration and bimodal distribution. Need dispersion of submicron particles. Use precursors and spray the solutions; gives significantly better products than conventional techniques.

Roadmap for 1-5 Years

• Process diagnostics – feedback information • Improved performance through microstructural development • New applications for APS based on functional properties at finer scales

(including sensors and solid oxide fuel cells Roadmap for 5-10 Years

• Process simulation leading to predictions of structure and properties • Thermal spray alternatives to sintering • New net spray forming of composites and graded structures comparable to

cast and sintered materials Rakesh Kapoor (Saint-Gobin High Performance Materials, USA) Multi-Functional Ceramics: An array of opportunities for Saint-Gobin High Performance Materials. Saint-Gobin was founded as a glass manufacturer, and is a leading producer of glass for architectural applications, but now utilises combinations of materials and combinations of processes for a range of high performance products. A series of case studies were presented to highlight the philosophy for product development. Case Study – Igniter Products Existing material systems operate at 1200-1350ºC, with 12-230V range, and generate spark in 3-5s. Roadmap Markers in the development process:

Customers will demand longer life (10X), faster ignition (< 1 sec), and wider voltage ranges (6V to 240V).

Is it possible to develop composite materials with tailored electrical properties?

Need to develop coatings (to minimize oxidation at 1350C + mechanical shock + thermal shock).

Need to understand and model the coupled phenomena (ternary diffusion in a coupled electrical, thermal and chemical gradient).

28

How is it possible to predict electrical properties for ternary and quaternary systems (use percolation theory extension?).

In response developed SiC/AlN/MoSiC three-phase composite and successfully modelled igniter behaviour. Case Study – Products to combat electrostatic discharge (ESD) events Rapidly increasing need for ESD control as microelectronics dominate more aspects of human life. ESD is increasingly critical for hard disc drive manufacturing.

Objective is tighter control of ESD properties (resistivity, dissipation, voltage decay); materials need to have good wear and optical properties for robot operations in wafer fabrication plants.

The solution was CERASTART TM, a CeO2 based ceramic having the resistivity tuned at the final processing stage. A wide range of materials is emerging to address ESD problems at the nano and micron scales. Case Study – Hi – end Abrasives Market for wheels and abrasives is worth €100M/year. Developed new product based on better control of porosity and change of shape of the abrasive grains. By adjustment of product density and permeability, the wear resistance was increased by 3-30 times. Key Trends / Messages (Specific)

• Rapidly increasing demand for multi-functionality in ceramics (and all high performance materials).

• Locally tailored - Structural, electrical, chemical, catalytic, functionality now emerging.

• Increasing need for tailoring electrical / ionic properties of ceramics. • Tailored coatings (mixed materials), locally applied, are growing. • Rapid growth of activity in ceramic/polymer nano-composites. • Next generation of abrasive products (highly wear resistant) is rapidly

emerging. Key Trends / Messages (General)

• There is an exploding number of opportunities for high performance ceramics, providing a rich source of scientific research problems.

• Many opportunities are driven by environmental or quality of life issues: medical imaging, homeland security, clean alternative energies, and cleaner water.

• New materials depend on mastering structure-properties-performance criteria • Engineering materials at the systems level is vital.

29

T Ishikawa (Ube Industries Ltd, Japan) Progress in Advanced Ceramic Fibres and their Future Perspectives Many types of continuous inorganic fibres have been developed over the past 30-40 years. The main target was to establish composite materials, which were light in weight and exhibited high fracture toughness. Carbon fibres are well established and have clear markets. Small diameter oxide fibres based on alumina and silica (such as Nextel) retain good properties up to 1200ºC, but at higher temperatures they degrade rapidly. It is expected that these existing materials and markets will mature in the coming 10 years. Two-phase oxide fibres were developed to provide a higher temperature capability; such eutectic fibres have not been commercialised because of the large diameters and low production levels. A range of SiC-based fibres has been developed with excellent heat resistance and high temperature oxidation resistance. In the next 5-10 years it is anticipated that one or two fibres will achieve bulk manufacture at low cost enabling them to be exploited in jet and gas turbine applications. Whilst the drive in fibre technology was primarily for high strength materials, there is growing interest in the functional properties that can be incorporated. For example silica fibres with a surface layer of titania-silica exhibit valuable photocatalytic activity and mechanical strength. Similarly, SiC fibres with a graded ZrO2 coating provides both good alkali resistance and mechanical strength. Roadmap Markers - 2010

• Oxide fibres – overcome high wall resistance and consolidate effective production processes

• SiC based fibres – development of effective processes to achieve large scale production at low cost

• Si-B-C-N type fibres – development of new functional fibres with photo-catalytic/semiconducting/piezoelectric properties

Roadmap markers - 2015

• Oxide fibres – establish single crystal fibres • SiC based fibres – stable supply of range of fibres; high strength, both initial

and after service; good creep and stress-rupture properties over wide temperature range; good through thickness properties; extended applications in aerospace and land based applications including jet engine components and gas turbine engine hot section components

• Si-B-C-N type fibres – development of new very high temperature fibres based on borides + SiC

MULTIPLE APPLICATIONS V Hongie Luo (Shangai Institute of Ceramics, Chinese Academy of Sciences SICCAS) Advanced Inorganic Materials and Their Applications in SICCAS In the first talk of this session, Hongie Luo told the audience of the four main research fields within SICCAS. Firstly, biomaterials research there has produced dental implants with bioactive glass coatings, hollow mesoporous SiO2 spheres for drug

30

delivery, macroporous CaSiO3 on which osteoblasts have been grown, and hydroxyapatite-CaSiO3 composites on which bone-like hydroxyapatite was formed in a simulated body fluid. Secondly, organic-inorganic bionic nanocomposites made of layered structures (shell, crab cuticle, bone, etc.) have been made and are promising candidates for various biomaterial as well as functional materials applications. Thirdly, nanocomposites are made by either an in-situ spark plasms processing (SPS) technique, by which micropowders can yield nanoceramics, or else a microwave assisted ionic liquid (MAIL) method. Composites have also been made with carbon nanotubes, just 0.1 wt% of which added to Al2O3 can increase its fracture toughness by 32%. Fourth, a great deal of work is continuing on energy materials, particularly materials for solid-oxide fuel cells (SOFCs). Such work began at SICCAS in 1995 and has mostly focussed on intermediate-temperature SOFCs based on an anode-supported film. One of these has successfully been able to use CH4 directly as a fuel at 800ºC without reforming or carbon deposition on the anode surface. The future research directions of SICCAS, as dictated by priorities identified by the Chinese government, especially include both biomaterials and energy materials. Any roadmap for China must consider its large ageing population. Such a population will certainly need the benefits of biomaterials in the not-to-distant future. Problems to be overcome include low mechanical strength, low bioactivity, and uncontrollable degradation. Moreover, the strength of the Chinese economy means that factories require ever more energy and the Chinese people expect an increasing standard of living. In addition, traditional power generation is far too polluting (not to mention exhaustible) to be sustainable in China; therefore, energy materials are another priority for China. One problem still to be overcome is the low catalysis at the anode when using hydrocarbon fuels. Setsuro Ito (Asahi Glass, Japa) Challenges for Overcoming Brittleness in Glass In the second and last talk of this session, Setsuro Ito presented the current state of the art in toughening glass, as well as a reminder of history. In 1995, 5000 people died in the Kobe earthquake. Hundreds of buildings were completely destroyed, yet rescuers found that some windows were actually still intact. This presentation tried to explain why some glasses are tougher than others. For many applications (automotive, container, display, etc.) the demand for lightweight glass continues to rise. Typically, to obtain such lightweight and still maintain the required area dimensions, the thickness of glass must be reduced; however, microcracks caused by contact damage cause a decrease in strength by a few orders of magnitude from the theoretical strength of glass (24 GPa), according to Griffith Theory. For very thin glass, this decrease in strength becomes a serious problem. The traditional way to toughen glass is to ensure that the surface is under a residual compressive stress, which would tend to close any microcracks that happen to form. Tempering (physical or chemical) or surface crystallisation are the usual methods employed. Unfortunately, tempering cannot always be used for low-α or thin glasses, and other methods are inappropriate for large areas. Brittleness is defined as HV/KC, where HV is the Vickers hardness and KC is the fracture toughness. In order to understand brittleness, it is necessary to understand the structural changes which take place under stress on a nm scale. It was found that by

31

reducing the amount of CaO in window glass (and making other subtle changes to its chemistry), a slower and larger deformation before fracture was achieved by the re-arrangement of the glass network. This result was an interesting suggestion for further development, although no roadmap as such was offered for the future.

CONSUMER PRODUCTS Herberto Balmori-Ramirez (National Polytechnic Institute Mexico) Impact of High-Energy Milling on the Production of Traditional and Advanced Ceramics Herberto Balmori-Ramirez gave a review of the effects of attrition milling on the microstructure of finished ceramics. Such high-energy milling is not only a more efficient use of input power, but also can yield highly reactive submicron or nano-powders with high surface areas, multiple microcracking, and high defect densities. Dr. Balmori-Ramirez used their own work on Al2SiO5 (kyanite, andalusite, and sillimanite) to demonstrate these effects. These minerals, which each have the same composition, were chosen because they are inexpensive, relatively abundant, and can be obtained with high purities. In addition, they each decompose at a different temperature into mullite plus silica. The decomposed products have unique microstructures that consist of a mixture of submicron mullite particles dispersed in a glassy matrix. With such a microstructure, it is possible to create mullite-glass ceramics. Mixing the attrition-milled sillimanites with Al2O3, MgO, or Mg3Si4O10(OH)2 (talc), they produced mullite, mullite-alumina, and forsterite-spinel composites, as well as cordierite ceramics. Attrition milling accelerates the decomposition kinetics, improves the sinterability, and changes the final microstructure, resulting in dense, equiaxed, micron-sized grains. Future considerations included establishing the minimum particle size/milling time required to produce noticeable effects in the microstructure and thermal decomposition, a comparison of the properties of ceramics produced this way as opposed to a more traditional way, an exploration into the possibility of producing other minerals in this way, and an analysis of the economic/energy consumption factors involved. Somnuk Sirisoonthorn (National Metal and Materials Technology Center Thailand) The Future for Ceramics for Consumer Products This talk presented a highly statistical overview of the global traditional ceramics and glass market, worth US$20 million/year. This market is comprised of 45% sanitary ware (1-5 pieces/person/year), 35% tiles (1-2m2/person/year), and 20% tableware (10-20 pieces/person/year). Indeed, 6.8 billion m2 of tile alone were produced in 2005 worldwide. The global production of glass is 115 million tonnes/year (29 million tonnes from Europe, 22 million tonnes from the USA, 19 million tonnes from Japan, and 45 million tonnes from other places). Major changes in consumer habits have been caused by a reduction of glass prices and changes in social lifestyles away from luxury brands to cheap and fashionable ones. Porter’s Diamond Model for the Competitiveness of Nations was used to make comparisons of the relative positions of the UK, Germany, Thailand, China, and

32

Indonesia (the USA was inexplicably left out of these comparisons). On the whole, Germany topped the list in most categories, helped by their entry into the euro zone (while the UK’s strong pound hindered its competitiveness). Five Forces Analysis was used to explain some of the findings, and these forces included the continual entry of new competitors into the market, substitutions (e.g., plastics vs. glass), the bargaining power of suppliers, the bargaining power of buyers (Ikea, Tesco, etc.), and traditional competition. It was concluded that the critical factors for competitive success were not the best raw materials resource or lowest labour costs, but rather process control capabilities and a skilled labour force; however, the UK has lately been losing market share heavily and continuously to China, which will be at the top of the global ceramics industry within the next ≈10 years. There is a demand for oven-safe tableware which could reach 500ºC, and the ceramics used must be both highly resistant to thermal shock and have low thermal expansion coefficients. Indeed, a future opportunity for the traditional ceramics industry is the development of such tableware. In addition, a roadmap for the future might also include self-cleaning tiles and antibacterial tiles as well as reducing the amount of energy used to produce glass or ceramics. Yoshito Nakanishi (National Centre of Metrology, Mexico) Importance of the Ceramic Industry in Mexico Yoshito Nakanishi gave a particularly Mexican perspective of the ceramics industry. Mexico has a well-established traditional ceramics industry, especially dynamic in the cement, flat glass, glass containers, bathroom furniture, and tableware sectors. It has virtually no presence in the advanced ceramics sector, although growth is foreseen in the application of advanced ceramics in electricity, biomedicine, and thermal materials. A great emphasis was also placed on the importance of measurement standards and the comparability of data. Although the Mexican ceramics industry also suffers from competition from plastics and cheap imports from China and elsewhere, since the introduction of the North American Free Trade Agreement (NAFTA) in 1994, production and especially exports (mainly tiles and cement to the USA) have greatly increased. The expansion in the cements industry may be particularly buoyed by the current explosion of house building brought on by the acute housing shortage in Mexico. The government has plans to build 23 million new homes over the next 30 years. For this reason, the cement industry is the most valuable ceramic sector for Mexico. The National Council of Science & Technology of Mexico commissioned a study in 2002 to produce a roadmap of technological goals through to 2015. This roadmap included the development of new technology to reduce the operational temperature of cement, to reduce the setting time of cement and increase its mechanical strength, to develop coatings to alter the surface properties of cement, and to reduce the ecological impact of ceramic production

33

BIOLOGY AND MEDICINE Larry L. Hench (Imperial College London, UK): Challenges for Bioceramics in the 21st Century Larry Hench began by stating that we are outliving the lifespan of our body parts and current surgical procedures use synthetic joint replacement material that have a lifetime of 15-25 years. This is unsatisfactory as our life expectancy increases. An alternative are transplants that are in short supply and have many risks.

He emphasised the need to shift from tissue replacement to regeneration. Hench reviewed his discovery of Bioglass®, the first material that was found to bond to bone, which launched the field of bioactive ceramics and how bioactive bioceramics such as bioactive glass and synthetic hydroxyapatite (HA), have been used as bone defect fillers in the clinic.

He then discussed recent important results that imply that the reason that bioactive glasses stimulate new bone growth is that the dissolution products of the glasses stimulate bone cells at the genetic level. This was discovered using cell and molecular biology techniques.

Hench stated that there are 5 challenges for bioceramics in the near future: 1. Development of scaffolds for bone tissue engineering strategies. E.g.

Bioactive porous glass scaffolds that bond to bone and dissolve; releasing ions that signal cells to lay down new bone

2. Scaffold development for soft tissue engineering, which requires the design of pliable resorbable nanocomposites.

3. Cell sourcing is an important challenge. The scaffold or the culture conditions should stimulate stem cells to differentiate into a pure and required lineage.

4. Delivery of antibacterial agents from scaffolds to surgical sites and help in wound healing applications.

A further challenge is for the regulatory bodies. A category is required for the

approval of bioactive materials that are implanted and then dissolve over time. Hench was emphatic in his plea that engineers and materials scientists must

work very closely with cell and molecular biologists and surgeons in order to understand the real science and mechanisms behind cell responses to biomaterials and for ideas to become real healthcare products.

Materials development will occur within the next 5 years, but the biological testing and approval for use will take 5-10 years. G. White (NIST, USA): The future of photonic applications of ceramics for Healthcare has already begun

This talk described the applications of photonics in diagnostics, imaging and as optical tools for treatment of tumours and discussed the limitations of techniques for these applications. Photonics is an analogue for electronics but using photons rather

34

than electrons. The main objective in this area is to allow early diagnosis and treatment and thus to offer treatments that are less invasive. The major aims are for the miniturisation of detectors involving the field of Materials Science (nanotechnology) and Biology (biological tags). However, most optical techniques are limited by resolution and penetration into tissue. The speaker described a number of different techniques and their advantages and disadvantages including. Fluorescence, Optical coherence tomography (OCT), Raman spectroscopy, Fibre optics, Solid state lamps, Optical traces and fluorophores, Quantum dots (currently these require the use of toxic materials) and Fluorescence Resonance Energy transfer (FRET) The use of Photodynamic Therapy (where toxins are attached to particles and are delivered to tumours) was also described, during which the particles could be activated by heating process to kill local, diseased tissues. Wolfram Hoeland (Ivoclar Vivadent AG): Future of Glass Ceramics as Biomaterials, Prof. Hoeland described the importance of control of nucleation and growth in glass ceramics to control microstructure and therefore the properties of the materials and thereby influence their potential applications in the dental field. He gave a review of the current status of the dental ceramics field and stated that Dicor had been the first glass ceramic developed for dental applications and had the major advantage that it is machinable. He summarised that there are now three types of applications for glass ceramics in dentistry 1 Glass ceramic on a metal framework (i.e. a bridge) leucite +apatite 2 Glass ceramics as single units (Leucite) – metal free 3 Glass ceramics as multi unit bridge (higher mechanical strength) lithium

disilicate glasses. Leucite apatite glass ceramics offer the potential for good colour matching while Leucite glass ceramics include the material marketted under the trade name“Empress”. This is a moldable materials and currently 30 M single units are used Worldwide Future technologies might include:

(i) Leucite apatite glass ceramic – contain rod –like crystals to provide the correct optical properties in the replacement tooth. Currently 60M units are produced worldwide.

(ii) Opal leucite glass ceramic surface nucleation and crystallisation Surface crystallisation – dendritic growth of leucite grains from surface. In the bulk, phase separation (nanometre scale) occurs to give an opalescent effect.

35

(iii) a) Lithium disilicate and b) Apatite glass ceramic He also detailed the potential for CAD / CAM technology using which the patient can have a restoration machined within one dental session. The current market is 3M units but it is growing very rapidly. The main problem has been the lack of adequate technology to produce a precise inlay. Lithium disilicate also shows the potential to be a machinable glass ceramic. The material exhibits volume nucleation and crystallisation. Using HTXRD reveals that the phases grow very quickly and then phase transform. Li2SiO3 can reach 700MPa biaxial flexure strength. He proposed that ideally, the future would allow us to be able to machine dental bridges directly: the framework could be machined and then glass ceramics as veneers on high strength engineering material substrates (sintered ceramics) e.g. zirconia He summarised that there is a good future for glass ceramics in dental applications in restoration but that there is also potential for the materials in terms of their bioactivity for implantology. Mike Swain (University of Sydney, Australia): Advanced Ceramics for Dental restorations: are stronger ceramics better?(delivered by L Hobbs) Prof. Hobbs summarised the structure of tooth enamel and dentine and suggested that dentine is an ultra smart nanostructured composite material. He stated that one of the issues in the treatment of carious lesions is how much dentine and enamel should the surgeon remove? He also questioned whether material should be removed at all. He described the repetitive cycle of restoration and that each time material is removed a new interface forms and bacteria can get in again to cause new problems. Each procedure requires more tissue to be removed until the root of the tooth is damaged and root canal filling is required. Prof. Hobbs discussed the issues that are driving the ceramics in dentistry for the future and summarised the various areas of research including further development of traditional cements based on acid base reactions – ZnO, silicate, GICs including novel cements, mineral trioxide, and bioglasses. Revolutionary technologies identified include:

(i) CAD / CAM - however, all ceramic crowns can cause large stresses building up at the margins.

(ii) Y-TZP endodontic posts (where some tooth root is available into which to anchor the prosthetic. However, the populairty of this material is declining – it is too rigid (E too high ) and there has been concern about tetragonal to monoclinic transformation.

(iii) Hydroxyapatite coatings on posts and stems. (iv) The development of a whole system using Y-TZP. Completely metal free

(tool kit required to be supplied to implant posts)

36

Threats to Ceramics in Dentistry • Failure of zirconia base structures with (this has been an issue with yttria-

stabilised TZP femoral heads) • The use of therapeutics which would eliminate caries diesases • Social security medical insurance failing to pay for the procedures • Reduction in sugar consumption Julian Jones (Imperial College, London, UK): Bioactive Glass Tissue Scaffolds and their 3-D Characterisation Dr Jones discussed the need to move from the replacement of damaged tissues to regeneration. His strategy is to use materials that can stimulate the body’s own regenerative (healing) mechanisms. He focused on bone tissue engineering and related how bone can heal itself if the defect is small but requires a template or scaffold to guide and stimulate bone growth if the defect is above a critical size. He concentrated his talk on scaffold design and characterization. The criteria for an ideal scaffold for bone tissue engineering are that the material is biocompatible and has an interconnected porous network with interconnects large enough to allow tissue to populate the scaffold in 3D. Scaffolds should resorb as the tissue repaires and provide signals to bone cells to stimulate matrix production. The scaffolds should also be sterilizable and be easy and cheap to produce to FDA standards. Dr Jones’ materials of choice are based on bioactive glasses, which bond to bone because they form a hydroxycarbonate apatite ( HCA) layer on their surface on contact with body fluid, which forms a bond to the bone mineral. Bioactive glasses also stimulate new bone growth (osteoproduction) because their dissolution products stimulate the genes in the osteoblasts, as shown in gene microarray studies. This activation is dose dependent. The Bioglass® composition has been used in powder form for many years but it is difficult to produce scaffolds from this composition as the glass crystallises on sintering. However sol-gel derived bioactive glasses have been foamed to produce scaffolds suitable for tissue engineering. Advantages over melt-derived glasses are; the ability to form a porous scaffold, enhanced bioactivity, controlled resorbability, nanoporous texture (diameters 2-20nm) that enhances bone cell response and a wide range of compositions. Recent studies by Jones and colleagues have found that within 14 days of growth on phosphate free glass scaffolds, primary human osteoblasts lay down mineralised bone matrix, without the addition of growth factors and hormones(w/o dexamethasone or glycerophosphate). This is unique to bioactive glasses. He then discussed the characterisation tools available for scaffolds. Percentage porosity is not sufficient to describe the structure of scaffolds, pore size and interconnectivity that are most important. X-ray microtomography (µCT) is required to obtain 3D images of pore interconnectivity. However, the structures must be

37

quantified. This can be done by applying computer algorithms to the µCT data. Dr Jones showed how similar the scaffold pore networks were to trabecular bone. In order to obtain good population of the scaffold with cells, a bioreactor must be designed. The µCT data can be input into finite element models that can determine optimum flow rate for fluid through the scaffold, which can be fed into bioreactor design. Mechanically, the bioactive glasses can match cancellous bone for compressive strength (5 MPa), but not in tension, therefore in vivo applications are limited. Ideally, a scaffold would be developed that would have the toughness of bone while maintaining the bioactive properties of bioactive glasses. This may be possible by developing bioactive inorganic/ organic hybrid scaffolds via the sol-gel foaming process. The future (Road map)

(i) There is a need to obtain in depth knowledge of cell response mechanisms as a function of atomic, nano and macrostructures of scaffolds.

(ii) Bioreactors must be designed for best 3D tissue growth (iii) 3D image analysis Improved algorithms for complex structures (iv) Materials must be developed that combine the properties of bioactive

ceramics and glasses with the toughness of polymers. This can be achieved by developing inorganic/ organic nanoscale composite scaffolds, however the chemistry is complex and it will take time to develop ideal scaffolds for in situ bone regeneration. If direct implantation into load bearing sites can be achieved, the complex issues of cell sourcing and bioreactor design may become irrelevant, if the cells in the body are utilized and the body becomes a natural bioreactor.

Away from research, the FDA / EU regulations need to be improved. At present, there is no approval system for a material that acts as a device, is bioactive and dissolves over time; scaffolds are neither devices nor drugs. The regulatory bodies are working on this problem.

TRANSPORTATION Tokuyuki Takahashi, (Toyota Motor Corporation, Japan): Materials Innovation for Forthcoming Automobiles Currently thee are 0.8 billion automobiles in the world; expect 1.6 billion by 2030. Accepting the contribution of vehicle emissions to the problem of global warming and the fact that there will be a peak in global oil production in 2020, Toyota has developed the following R & D principles for future automobiles:

(i) Zeronise (no accidents or pollution or congestion) and (ii) Maximise (the enrichment of the individual)

38

The ultimate Eco vehicle will have (i) high efficiency, (ii) lower emissions, and (iii) fossil-free fuel. Existing hybrid cars can achieve 60 mpg, typically twice that of conventional petrol cars. Developments require improvements in the battery (lower price materials whilst maintaining safety), and in the inverter (improved heat resistant materials to increase efficiency). For lower emissions, the vision is a car that makes the atmosphere cleaner the more it is driven; this require improvements in engine timing control and the greater use of catalysts to reduce pollution. For alternatives to crude oil as power source, possibilities include:

(i) Liquid bio fuel, to achieve carbon neutrality – there is current work on a range of plants in different parts of the world, but engine controls would need to change if implemented.

(ii) Fuel cells – since 1992 Toyota have worked on fuel cell stacks; for real progress need costs to be reduced to 1% of current values, and reliability to be improved.

The final aspect is a no-injury society. At present motor vehicle accidents involve 10/1000 of population in Japan, and 40/1000 in Europe and the USA. There should be significant reductions with the introduction of mm wave radar systems which can detect pedestrians and other vehicles so that the brakes could be applied automatically. A further vision is vehicles that can improve heath of the driver, by energising the heart and stimulating the brain. TRANSPORTATION I Mark van Roode (Solar Turbines Inc USA) Applications for Ceramics in Gas Turbine Engines Most ceramics in gas turbine are Si based such as SiC, Si3N4 and SiAlONs. Gas sintered Si3N4 fabricated with 300 MPa creep limit and 700 MPa strength, and tested for 1000’s of hours. Limitations of ceramics are: low fracture toughness (compared to metals) of 6 – 9 MPa m1/2; size limitation – 30 cm approx; poor impact resistance – major cause of failure; corrosion – require environmental barrier coatings which create thermal expansion problems. Big driving force is emissions – hot walls provide lower CO. Lean burn lowers NOx. Ceramic matrix composites have net shape capability but a maximum temperature of 1250 °C. Monolithic ceramics tested to 1400 °C but only for short times. Requirement: monolithic materials that will work above 1400 °C, and ideally above 1500 °C for 30,000 hours without thermal barrier coatings. Drivers for future: Cost is very important. Must be the same or less than metal alloys, which also continue to improve. Current cost of ceramic systems 2-6 x higher than metal.

39

Roadmap For the near-term roadmap, accumulation of hours on existing systems for ceramics, environmental and thermal barrier coatings 1 – 5 Year – First ceramic matrix composite in production by 2010 Design, manufacture and test small efficient (40%) ceramic turbine. 5 – 10 Year – Demonstrate 1200 °C and 1370 °C platforms. Requires: a major fundamental materials science revolution. Thomas Yonushonis (Cummins Inc USA) Ceramic Research and Successes in Diesel Engines Diesel engines are extremely important due to efficiency – 45% max compared to 25 – 30 % for petrol. Ceramics have formed a very important part of diesel industry for some time. Huge volumes for injector links, check ball and compressor brake pads. Used to improve durability and tribology. ZrO2 plunger in injector 50 x lifetime over metal. Drivers: Higher fuel pressures – above 2000 bar Lower lubricities – Sulphur removal from diesel increases wear Cost Durability Delivery Emissions Roadmap Improvement to emissions Provide high surface area ceramics which are good for 1,000,000 miles Improve high temperature wear resistance. Michael Readey (Catarpillar Inc USA) Materials Research at Caterpillar Large recent increase in fuel prices means that efficiency is more important than ever – 3 fold increase in 10 years. Efficiency of production diesel is around 45 %. 50+ %; possible but expensive. Key areas for ceramics:

• Thermal coatings: heat rejection (2% improvement in efficiency), reduce metal temperature, environmental protection

• Valves: Oxidation reduction, wear resistance, higher strength at higher temp. • Low mass turbos: Faster spin up can get air in faster when high demand

required. • Filters: Collect carbon. The filter is regenerated by heating – must be strong

and have high thermal shock resistance. Roadmap 10 years – Near zero NOx, particulates and hydrocarbons for large plant.

40

20 years – Zero CO2 – emerging energy such as fuel cell, solar and wind. The speaker was informed that the last big jump in efficiency occurred in the ‘70s as a result of fuel prices and asked whether the same would happen now, to which the speaker replied yes, using higher pressures and higher pressure turbos. The speaker was also asked to comment on the increasing use of Pt in such technologies as fuel cells and catalysts, and how it could be sustained to which he replied more efficient ways to use it must be developed.

INNOVATION AND INVENTION Rodney Miller (Kyocera USA) Kyocera’s Vision for the Future Kyocera Ceramic was established in Japan in 1959 to develop ceramic components to underpin TV Technology, in particular the operation of the electron gun. Two years later they opened the first manufacturing plant in the USA, making ceramic heaters for transistors, thereby helping the fledgling Silicon Valley developments in ICs. Today Kyocera is a market leader in ceramics with 10% pre-tax profits on a turnover of $10B. The core philosophy is “Do what is right as a human being”. Visions for the future: IT and communications sectors – significant expansion envisaged. The fact that 4.6 billion people do not yet have a cellphone means that there are still tremendous opportunities. In the USA, each household has typically 26 digital products; the average US household spends $1200 per year on digital products. Kyocera perceive expansion of organic materials for packaging, and substrates for mobile systems. In the Environmental sector, there will be further expansion of the use of piezoelectric ceramic common rail fuel injectors in diesel cars (currently 50% sales in Europe); the operating pressure will increase by 30 % to 2000 bars to enhance engine performance and a move into the petrol car market. Quality of Life Sector As the population grows older, there will be a 10x expansion in the number of hip joint and knee joint replacements providing significant opportunities for materials suppliers. The underlying philosophy of Kyocera is high added value and diversification. Henry Kressel (Warburg Pincus) The Global Business Model for Technology Companies The talk by Henry Kressel focussed on the requirements for High-Tech Ceramics industry for the future. The key factors identified included

• The ability to globalise very rapidly due to digital communications infrastructure and proper selection of logistics and locations

• Changes towards higher efficiency and cheaper production

41

In the Technology Sector and the area of Software Development there has been a tremendous growth in the number of scientific papers from Asia. Also there has been a move from industry to academia in the innovation of new technology and this is as a result of the changes from basic research to applications-led research. In the past then patenting was predominately carried out in the Western World and relatively little respect was given to the implications of these patents by developing economies, particularly in the Far East. However, patenting is now being viewed seriously across the World and the most important sectors include (in order of decreasing patent numbers per year):

• Japan - Telecommunications, IT and electronics • US - Chemicals, materials and instrumentation • South Korea - Automotive and transport • Germany - Energy and power • China – Pharmaceuticals and medical applications • Russia - Food and agriculture

The reasons for this global localisation of patent areas is related to the balance between labour costs, raw materials costs and the value of the product. For example in the automotive industry, the final assembly is often carried out by hand and this labour-intensive process leads to a balance in favour of production in the Far East. However, for products such as CMOS wafers however (a high value product) the cost of production in the US is similar to that in Taiwan and China with the requirement for highly automated plants. However, the main thesis of the lecture was that for many new products there may be competitive advantages in performing design operations, software coding and manufacturing in different parts of the world. This globalisation of development, manufacturing, distribution and sale of products is only possible because of the very rapid and effective communication links that are now available.

• Solid state lamps • Optical traces and fluorophores • Quantum dots (currently toxic materials ) • Fluorescence Resonance Energy Transfer (FRET)

Joel P. Moskowitz (Ceradyne Inc. USA) A Company’s Vision Moskowitz began with an amusing history of how he founded Ceradyne Inc from scratch in 1967, recognising the need for advanced technical ceramics. The focus was on non-oxide ceramics. Ceradyne’s hot pressed boron carbide has a uniquely high hardness to weight ratio. It is so hard and light that it can be used to stop bullets as body armour. Sintered reaction bonded silicon nitride is the basis of ceramic combustion engines (cams rollers and bearings) that can reduce particulate emissions. Ceradyne Thermo Materials division is a fully integrated manufacturer of ceramic radomes, or nose cones, for missile systems, using fused silica and silicon nitride based ceramics.

42

Ceradyne, utilizing its Transtar™ translucent aluminium oxide, has developed precision high volume fabrication techniques for their Clarity™ ceramic orthodontic brackets, which have been used in the treatment of almost one million patients. Ceradyne is ranked as a top growth company in the US, showing that advanced ceramic processing and design has a place in cutting edge products. The company strategy is to start with a material with novel properties, and to then go in search of an application for that material, with the US military being a high paying consumer. A mission for the next 5 years is to continue to develop boron nitride and titanium diboride ceramics and to be able to produce boron carbide on a mass scale more economically so that it can be used for widely as a protective material, for example to armour plate all military vehicles such as personnel carriers. Silicon carbide (SiC) and silicon nitride (Si3N4) are currently used, as they are cheaper to produce.

43

COMMON MESSAGES FROM SYMPOSIA AND ROADMAPPING

International Trends and Business Perspectives

Globalisation – important issues:

New markets, availability of talent, availability of raw materials, supply of energy, health and the environment, standardization, I.P. Must adopt a global view.

Concerns: Protection tariffs, IPR, raw materials and energy sources Key messages from successful companies:

• Driven by customer needs and challenges • Corporate based R & D aided by government support • Advancement of society and mankind

Today – many boundaries eliminated

• Location of talent shifting • Communications allows more diverse groups to interact • Availability of water and energy is critical

Education for the Future Need to educate students, employers, customers, politicians and general public Importance of Ceramics as an Enabling Technology. Needs:

• Level playing field (trade, IP, standards) • Education • Energy and water supplies

Electronics

Applications include: communications, Si packaging, and automotive industries. Needs

• Smaller packages/components; greater functionality • Components/systems made more rapidly at lower cost • Low temperature processing; materials compatibility • New materials (may take 7-10 years to develop). • Ability to sinter without grain growth

Issues for Packaging

• Integration, smarter package; is yield sufficient to improve complexity significantly?

44

• Greater complexity – need new manufacturing methods • Need interdisciplinary approach to develop new components/systems. • Increased local complexity • Consider microfluidics?

Issues for Thin Films

• Understand and control failure mechanisms in multilayer packages • Effects of strain and size • Need for new fabrication techniques?

Advanced Ceramics for Si Processing – expensive pure materials (SiC, BN, AlN) Issues for Ceramic Nanoparticles

• High surface area nanoparticles for sensors – how to produce powders without agglomeration.

• Procedures to scale up batches • Chemomechanical polishing • Increase in functionality • Need for standard nanotoxicity testing.

Energy Energy and environment are in many cases inextricably linked since energy often pollutes the environment (CO2 from hydrocarbons, waste from nuclear) so that there was some overlap in the Energy and Environment sessions. Energy is a key area for research worldwide and ceramics have an important role to play in both energy production, storage, transmission and conservation. Theme areas revealed by the Energy Session talks are:

• Energy production, storage and distribution • Energy conservation and energy efficiency • Impact of ceramic nanotechnology in e.g. fuel cells, thermoelectrics,

photovoltaics, nuclear fuels and superconductors. • Improved nuclear reactor and fuel designs which limit proliferation but

enable an expanded nuclear power programme. • Ceramics in fusion for first wall and tritium breeding. • Development and commercialisation of solid oxide fuel cells. • Improved energy saving devices such as high temperature ceramic based

engines. • Improved storage devices (supercapacitors, Li ion batteries). • Clean coal technology. • CO2 sequestration.

Challenges and barriers to commercialisation include:

• Performance and reliability • Hydrogen infrastructure

45

• Field testing and cost reduction

Other opportunities: • Thermoelectric materials • Long-distance energy transmission: reducing cabling losses

Environment Key environmental research topics for the next decade include use of ceramic technology in providing clean water, air and soil. Topics of international significance include

• Development of a range of nanoporous filtration membranes and nanoparticles for remediation of sites contaminated with both hazardous and radioactive species.

• Use of low temperature ceramics such as geopolymers for applications from radwaste immobilisation to bone prostheses.

• Clean air, water and self-cleaning surfaces by use of TiO2-based photocatalysts.

• Recycling and reuse of spent nuclear fuel and military Pu. • Increased recycling and reuse of high volume ceramics (cements, glasses,

refractories). • Reduced reliance on heavy metals in e.g. Pb in electroceramics, Hg in dental

fillings. • Development of sustainable raw materials • Focus on responsible manufacturing and higher process efficiencies • Reduction of energy costs and process gas emissions

Roadmap target with timescale less than 1 year

Building products with acid and fire resistance.

Roadmap - Impact within 1-5 years

Immobilisation of low/intermediate level waste (Cs, Sr) Reduction of CO2 production through use of geopolymers in concrete production

Refractory castables Roadmap - Impact within 5 – 10 years: Potential biomaterials for bone replacement Nanoporous materials Replacement of OPC in buildings

46

Glass and Optical Materials

Applications include display technology, I.T., biomedical implants, chemically resistant packaging, armour…. Issues to address

• Toughness of glass • Improved consolidation processes and manufacture • Homogeneity • Minimising defects in glass and transparent materials • Nano-powders for Nano-glass • Electrochemical methods to design glass • Environmental – chemical processes • Energy efficient processes • Communication at interface with other disciplines • Future workforce

Multiple Applications

Drivers

• Energy costs (examples: CMCs for turbine components, SOFCs) • Ageing population (example – bioceramics) • Environment (examples: particulate filters, photocatalysts) • Multiple demands (example – multifunctional materials, varying locally)

Ingredients for successful application

• Unique properties and combination of properties – the only solution • Unique expertise/innovative fabrication • Balance of cost/performance/reliability/demand

Ingredients for successful process innovation Produced faster, better at lower cost. Roadmap: 1-5 Years

• High temperature applications of CMCs • Energy harvesting of piezoelectric fibres • SiC-SiC brakes

Roadmap: 5-10 Years

• SOFCs provide heat and power to offices and buildings • New generation of bioceramic implants

47

Consumer Products The roadmap for the future of ceramic consumer products can be said to lead to higher-temperature tableware, better cement, and products with more functionality and less ecological impact. Specifically: Attrition Milling

• Establish the minimum particle size/milling time required to produce noticeable effects in the microstructure and thermal decomposition

• Compare the properties of ceramics produced this way as opposed to a more traditional way

• Explore the possibility of producing several minerals in this way • Analyse the economic/energy consumption factors involved

Traditional Ceramics

• Develop ceramics that are both highly resistant to thermal shock and have low thermal expansion coefficients for use in tableware which could reach 500ºC

• Develop self-cleaning and antibacterial tiles • Reduce the amount of energy used to produce glass or ceramics

Cement

• Reduce the operational temperature • Reduce the setting time • Increase mechanical strength • Develop coatings to alter the surface properties of cement • Reduce the ecological impact of ceramic production

Biology and Medicine

Three main areas were addressed:

Dental ceramics Bioactive Ceramics for Orthopaedic applications Diagnosis, imaging and treatment methods

Dental Ceramics Present The use of ceramics in dental applications includes:

• Restorations • Endodontic posts • Inorganic cements

The developments in bridges, restorations and crowns were discussed. The use of Glass ceramics is now well established to provide excellent aesthetic matching with natural tooth. Until now there has been wide use of metallic substrates for bridges and

48

this has led to problems with metal-tissue interactions leading to discolouration and tissue damage. Currently the patient needs to return several times to the dentist to be fitted with a crown – but the potential for rapid prototyping in the dental surgery was discussed. Future Next 5 years - Ceramics will be investigated for use for long span bridges. The use of structural (high strength and high toughness materials such as zirconia) need to be developed. These ceramic substrates may solve some of the problems associated with metallic bridge substrates. Glass ceramics are currently based on lithium disilicate and leucite glass ceramics and these may be combined with apatite-based glass ceramics for enhanced colour matching and opalescence. The future developments of glass ceramics will be at the compostional and microstructural level to improve the aesthetic properties further. Better marginal bonding between the ceramic filling materials and tooth. Currently marginal leakage can lead to bacterial-mediated attack of enamel and dentine around restorations. Improved marginal bonding using new / improved cements and adhesives will provide longer lifetimes for these restorations. The use of CAD/CAM in dental surgeries for rapid production of implants and prosthetics was discussed. It is likely that in-chair measurement and design of restorations and crowns will increase over the next few years. Next 5 – 10 years – No clear objectives appear to have been set in the dental ceramic field. However, it is recognised that the bond between bone and tooth root implants (e.g. the bridge-posts) is important. It is likely that these developments will move more into the maxillofacial research areas such that bioactive ceramics and ceramic coatings will be of increasing importance. Bioactive Ceramics for Orthopaedic Implants Present A wide variety of biomaterial scaffolds are being researched, and these are based on bioactive ceramics, glass ceramics and glasses. The requirement for porosity in these implants (to allow bone-ingrowth and bone bonding) has been recognised. However, there are problems associated with the mechanical performance of the materials and also their physical structure and the characterisation of this structure. Much of the current work is focussed on the chemistry of the materials being developed and the ability to match closely with the structure and chemistry of bone and bone mineral in particular. Future Next 5 years There is still the need for the development of improved scaffolds for implantation. This can be achieved through better understanding of the relevant biology at the cellular, molecular biochemistry and gene levels. However, the difficulties associated with animal experimentation were discussed and it was agreed that a concerted effort

49

is required to develop a human-based in-vitro cell model that can accurately predict the behaviour of materials in clinical use. The importance of understanding more deeply the effects of the bioactive implant or scaffold chemistry was acknowledged during the Road-mapping exercise and the effects of the structural-functional behaviour of implants and scaffolds. The US members of the Road-mapping session all agreed that it was essential that the US government ensures the provision of long-term funding to encourage multidisciplinary research. This has been recognised for many years by EPSRC, BBSRC and MRC – and is clearly a good model with which to continue! Next 5-10 years A number of important areas of work were identified for the development of improved implants through multidisciplinary research:

• Obtaining a better understanding of the relevant biology –e.g. molecular biochemistry, cell function and physiology

• Obtaining a better understanding of the interaction between the material and the biological system

• Avoiding simplistic paradigms – but developing accurate in-vitro cell models • Obtaining a better understanding of materials science and biological

interactions at the nanometre level. Diagnosis, Imaging and Treatment Methods Present: There are a number of potential biomedical applications in the field of photonics and many of these are currently being investigated. These include

• Drug delivery and release (nanoparticles) • Diagnostics (interrogation) • Imaging • The use of therapeutic irradiation.

However, most optical techniques are limited by resolution and penetration (into the tissue to be investigated or treated). Therefore there is a need for the improvement of the performance of existing equipment and devices and the development of new diagnostic and therapeutic applications. The Future In the area of Diagnostics there is a need for the development of improved photonic –based imaging lasers, solid state lamps and detectors optical and photonic-fibres (glass fibre optics). The intention is to allow early diagnosis and treatment and thus to offer treatments that are less invasive. In the area of Therapeutics, there is a need for improvements in the field of photo- based energy delivery –e.g. to kill tumour cells. Here the use of Photodynamic Therapy is proposed (where toxins would be attached to particles and which would be delivered to tumours and activated via a heating process to kill local tissues).

50

Next 5-10 years Beyond the next five years further developments of existing technology are proposed and these include the miniaturisation of detectors which would require advances in Materials Science in the area of nanotechnology and in Biology (for example in the use of biological tags) The current limitations in terms of penetration and resolution will need to be addressed and the use of in situ methods will be developed such as:

• Fluorescence • Optical coherence tomography (OCT) • Raman spectroscopy • Fibre optics

Transportation

Transportation needs were discussed with respect to gas turbine and automotive, to include large vehicles and plant. Automotive can be split into the near term, such as improvements to conventional diesel, and long term, such as fuel cell and alternative energy sources. Requirements for gas turbine

• Improved fracture toughness, strength and impact resistance • Increased size capability – 30 cm at present – long way off large blades • Remove the need for thermal and environmental barrier coatings • Higher temperature withstand – improve efficiency • Cost – must be comparable to metal alloys to compete • Further develop ceramic matrix composite

Roadmap: 1-5 years:

• First ceramic matrix composite system will see production • Develop small all-ceramic test platform

Roadmap: 5-10 years: • Demonstrate 1200 °C and 1370 °C platforms – v. high efficiency • Fundamental materials science revolution required to develop the required

mechanical properties Requirements for large diesel

• Higher durability of ceramic – lower sulphur leads to lower lubricity • Improve high temperature wear resistance, shock resistance and stability

Roadmap: 1-5 years:

• Improvements in efficiency and emissions. • Provide high surface area ceramics (for post combustion filters) which are

good for 1,000,000 miles.

51

Roadmap: 5-10 years:

• Near zero NOx particulates and hydrocarbons for large plant. Requirements for alternative energy systems No accidents, pollution or congestion Roadmap: 1-5 years:

• Cost reduction of fuel cells – will require large advances in ceramics • Development of accident prevention systems

Roadmap: 5-10 years:

• Further reduce cost – fuel cells must cost 1% of current • Improve hydrogen storage and infrastructure

Innovation and Invention

Common themes • Education of workforce (and future workforce) • Interdisciplinarity • Methodology for enhanced innovation • Development and applications of standards

Materials, particularly ceramics, requires interdisciplinary collaboration IT is essential; data needs to be accessible and reliable (need for standards). Information exchange must be respected and agreed. There are I.P differences around the world – need international agreement. Student numbers in materials programmes in USA and Europe is relatively static; PhD students in Asia is increasing exponentially. Some materials have become commodities – implications for manufacture/cost/energy Roadmap 1-5 Years

• Refinement of education curricula • Definition of dissemination strategy to meet global needs • Develop and disseminate property and performance standards • Foster Interdisciplinarity – develop new funding paradigms, joint meeting (but

less conferences) Roadmap 10 Years

• Assess whether we have become a ‘materials’ society • Stronger interdisciplinary alliances • Global integration

52

Suggestions • International accreditation of undergraduate and postgraduate programmes • Summarise I.P agreements in different global sectors - aim for standardisation.

53

Contributors to the Report

S Best, Department of Metallurgy and Materials, University of Cambridge

P Bingham, Department of Engineering Materials, University of Sheffield

J Binner, IMPTE, University of Loughborough

T Comyn, Department of Materials, University of Leeds

R Freer, School of Materials, University of Manchester

J Jones, Department of Materials, Imperial College, London

W.E.Lee, Department of Materials, Imperial College, London

S Skinner, Department of Materials, Imperial College, London

R Ubic, Department of Materials, Queen Mary, University of London

J Yeomans, School of Engineering, University of Surrey

54