Various RCUK funded projects at Loughborough University over the years have delivered significant foreground intellectual property and technology know-how related to the fabrication of nanostructured materials with outstanding properties, surpassing some of the commercial counterparts, relevant to the energy, electronic security and in particular healthcare sectors. Specifically it has been demonstrated that the hydrothermal ageing (HTA) resistance of zirconia based ceramics can be enhanced significantly by retaining a nano grain size below 180 nm even at low density components. This is highly relevant to the ~$5B hip replacement market where concerns about the toxicity / wear debris in metal and polymer components renders all-ceramic solutions increasingly attractive. HTA degradation (the unwanted conversion of tetragonal zirconia to a weaker monoclinic form in an aqueous environment) is the Achilles-heel for the use of zirconia ceramics in biomedical sector and was the reason behind the well-publicised failure of zirconia hip replacements around 2000. Thus, when HTA is countered, new opportunities open up. The proposed technology (involving novel nano-suspension control, granulation and then microwave assisted hybrid heating as well as flash sintering regimes; zirconia toughened alumina and zirconia ceramics will be considered) aims to deliver very small zirconia grain sizes that will both assist current compliance (e.g. ISO 13356, ISO 633-3) and open up novel all-ceramic hip replacements via multi-fold enhancement in HTA-resistance of porous and dense graded zirconia based structures. The methodology will be applicable to ceramic-metal graded implant structures also with suitable modifications. The retention of nano-size throughout all stages of ceramic component production is critical to delivering the target end properties that will assist the health and quality of life in a growing ageing population. This will be achieved via the development of implant structures (applicable for hip/knee prosthesis, finger joints and jaw & skull repairs) that deliver improved mobility over a longer time period thus reducing reliance on repeat surgery and in some cases confinement to use of wheelchair.

Ceramic materials are used in a wide range of applications including motion sensors, for energy storage in electric vehicles, dental replacement, hip and knee implants, cutting blades, and body and vehicle armour. They are exceptionally durable, even at high temperatures and in corrosive environments, and can be reused or recycled at the end of their life. However the high cost of manufacturing is a major barrier to the use of ceramic materials. Producing a dense strong ceramic material with minimal porosity requires heating to very high temperatures well over 1000 deg.C typically for many hours. Recently scientists have discovered that the temperature and duration of the ceramic densification process (sintering) can be significantly reduced by passing an electric field through the ceramic during the heating process. This "flash sintering" process, so-called because the material densifies extremely rapidly within a few seconds and often with the simultaneous emission of light, has potential to significantly reduce energy use in industrial-scale ceramic manufacturing and reduce emissions of greenhouse gases from the process by up to 40%. The flash sintering technique may revolutionise the ceramic manufacturing industry by reducing the cost and environmental impact of producing ceramic materials. In this research project a detailed investigation of the flash sintering method will be undertaken to establish the viability of this technique for use with a wide range of ceramic materials and particularly to understand the underlying mechanisms which cause the flash sintering effect. A flexible flash sintering facility will be established which can be used to flash sinter a wide range of ceramic materials. Composite materials with varying electrical conductivity will be flash sintered under different conditions. The results will used to understand the effect of both the material properties and the variables involved in the process (e.g. electric field strength, current, voltage, and temperature) on the observed flash sintering behaviour. Materials will be characterised by measuring their density, imaging using scanning electron microscopy and mapping the chemical composition, and using X-ray diffraction to determine any changes to the phase composition of the materials caused by the flash sintering process. New insights will be gained by flash sintering for the first time a structure made of layers of ceramic composite materials graded by composition and examining how the flash sintering behaviour changes compared to samples containing each individual composition. The results of this project will be used by our industrial project partners Lucideon and Morgan Advanced Materials in the industrial development and application of flash sintering technology.

Energy demand is growing and our society faces a challenge to find sustainable sources with minimal environmental impact. Existing technologies such as solar, wind and geothermal have been deployed and effort to improve their physical and cost effectiveness is ongoing. Another source of renewable energy available which has not been harvested to its full potential so far is "waste" heat. It arises from a variety of sources, from household boiler to large scale power plant, and a striking example is the conventional combustion engine in which 60 % of the energy produced is lost in the form of heat. The possibility to design a semiconductor device made of p-n junctions which when exposed to a temperature gradient will output electrical power is an attractive solution for the automotive industry to improve fuel efficiency, lower the carbon foot print and end-user costs. This device, called a thermoelectric generator has been successfully used for aero-spatial application or in its converse form as Peltier cooler, contributes to all component of the energy trilemma. The major barrier for a widespread dissemination of this technology as energy harvester is the high raw material costs and a lack of material for high temperature operation. This research will investigate new classes of inorganic oxide composed of earth abundant elements presenting electrical and thermal properties suitable for integration in a high temperature thermoelectric generator. Efficient thermoelectric materials possess high electrical conductivity and low thermal conductivity which, in a standard semiconductor picture, are antagonistic properties. Focusing on the high temperature spectrum, oxides materials will display the chemical stability required for the device to function reliably. Since the majority of these materials are electrically insulating, the concept is based on identifying structure patterns that have hidden electronic lattice which could act as conducting channel. Similar concept has been successfully applied on layered oxides where only competitive p-type thermoelectric materials where produced. The project aims to explore the possibility to use the strong correlation between electronic, thermal and magnetic lattice to circumvent the limitations encountered in this class of materials and expand our understanding of this complex compounds. A specific objective of the project is to prepare poly- and single crystalline layered oxides derived from the trirutile structure, measure the high temperature conductivity and thermopower and optimise the thermoelectric property using chemical doping to obtain both p and n type compounds. The layered structures of the proposed compounds are conducive to exotic magnetic properties and more complex phenomena such as Nernst-Ettinghausen effect and spin Seebeck effect will be investigated.

This proposal is a Platform Grant renewal. Our previous grant allowed us to develop the key characterisation facilities and enabled us to understand fully the materials that were the study of the grant. These materials were low loss microwave dielectrics, ferroelectric materials and thin films of these materials. The Platform renewal will build upon some remarkable discoveries that the team, including the key PDRAs, has made over the last 4 years and centre around functional materials for devices operating from microwave to millimetre wave or from MHz to THz. First it is important to explain the Materials Science progress that forms the underpinning technologies that will enable us to use the Platform grant to build new devices. At the heart of microwave devices are resonators that require low dielectric loss or very high Q factor and the target is to aim for very high Q dielectrics. Our previous Platform grant and indeed prior support from EPSRC allowed us to discover very low loss, high Q materials. This culminated in two significant discoveries. 1 First we were able to use low loss resonators as sensors for liquid sensing 2 Second, we demonstrated that by using a very high Q resonator we could achieve maser action at room temperature and in Earth's field - published in Nature 2012. This platform grant will enable us to build upon these discoveries. 1) Advanced Characterisation: In the first theme the aim will be to carry out a series of qualifying experiments to determine the best possible conditions and materials for sensing over the wide range of frequencies available to us (Hz to THz) 2) Microwave and mm wave sensors: The third theme takes the science to application. We will use the resonators for analysis of ions, biomolecules, proteins and cells. The sensitivity of the resonators allows nanolitre quantities to be analyzed very rapidly for possible cancer cell detection in blood and bacteria in water. 3) "UMPF" and "HEP" Cavities: In the second theme we aim to make UMPF (Ultrahigh Magnetic Purcell Factor) and "HEP" (High Electric Purcell) cavities. These are small resonant cavities with a very high Q given the very small mode volume and success here will enable us to improve electron paramagnetic sensing dramatically and enable single cell detection. Success in these new themes for the Platform would represent a remarkable step-change in technology.

Functional Materials and Devices (FMD) is a rapidly evolving subject which underpins many aspects of modern life such as antennas, energy storage devices, multicomponent sensors and smart materials. At a segment size of ~£3Bn p.a., the UK represents ~25% of the total EU production. However, the FMD sector in the EU and UK relies heavily on raw materials which have geopolitical, geological and environmental constraints. The response to materials scarcity and environmental restrictions depends on the industry, but companies indicate that resource efficiency, R&D, and innovations for substitution are necessary. Our vision is to utilise materials engineering, multiscale modeling, advanced manufacturing, supply chain/life cycle analysis and industrial partnerships to establish an holistic response to substitution and sustainability within the UK FMD sector. 6 mission-critical projects have been identified by the investigators which will be the initial focus of the programme. Follow on projects will be developed during the grant in collaboration with an expanding portfolio of industrial partners. i) Elimination of expensive RE-oxides from the fabrication of multilayer ceramics capacitors (MLCC): Currently, the lifetime of an MLCC is enhanced by the use of ~2wt% of RE-oxide (RE = Dy, Ho). Dy is the number one most endangered element according to the US government. Eradicating Dy and Ho from the fabrication MLCC is thus an urgent priority ii) RE substitution in magnetocalorics for energy efficient refrigeration: Dy is also a critical element in magnetocalorics for energy efficient refrigeration. RE-free strategies to enhance the giant magnetocaloric effect will be explored so that this highly efficiently refrigeration technology can be made commercial. iii) Replacement of RE based oxides in dielectrically loaded satellite receive antennas: Ultra small GPS microstrip patch antennas utilize ceramics based on barium RE titanates (BRET, RE = Nd and Sm) since these are the only currently available high permittivity (80-90) materials with the required properties. We will explore new multilayer antenna designs on RE free, low cost dielectric substrates such as BaTi4O9. iv) Manufacture of actuators using PbO-free piezoelectric oxides: Environmentally friendly, PbO-free piezoelectrics) have been developed over the last decade as potential replacements for Pb(Zr,Ti)O3 (PZT). Device fabrication and characterization will be studied along with an investigation of critical issues concerning direct integration into end-user applications. v) Replacing exotic compounds with robust oxide ceramics in thermoelectric generators Currently, the best thermoelectric materials (Figure of Merit, ZT > 1) for waste heat harvesting are based on tellurides, antimonides and germanides. Not only are these compounds toxic and in short supply but they are also unstable at the proposed operating temperatures. Thermoelectric generators based on equally performant, more abundant and less toxic oxide materials will be developed vi) Manufacturing routes to sustainability in light emitting diodes (LEDs) Energy efficient LEDs have the capacity to replace completely conventional W based filament light sources but scaling up this technology results in critical thermal management problems which are alleviated by conductive Ag paste, too expensive to meet the envisaged market. New strategies to dissipate heat will therefore be explored so that W based high powered lighting can be replaced by LED energy efficient equivalents. All projects will be make use of multiscale modelling in device design, materials development and understanding physical properties. In addition, a Supply Chain Environmental Analysis Tool (SCEnAT) will be utilized on all projects. SCEnAT is coded based on the state-of-the-art methodology in carbon and has been used by leading industry such as TATA, Rolls-Royce and Sheffield Forgemasters International.