Substitution and Sustainability in Functional Materials and Devices

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.

People: PDRAs will be involved in a multidisciplinary team spanning experts in materials engineering, functional device architecture & manufacture, and supply chain modelling. They will benefit from the involvement of a number of industries, exposing them to work practices and time-scales outside of academia. These partnerships will lower the barriers to future collaboration and provide an invaluable source of contacts for the researchers, allowing them to make informed decisions about their future careers. The impact on younger, recently appointed staff will be to enhance their management experience and help create a track record in large collaborative research grants, thereby creating opportunities for additional research funding from national or transnational bodies. PDRAs will become skilled advocates for UK science and technology by engendering the skills to act as future research leaders who will facilitate the next generation of British scientific endeavour.

Knowledge: The senior management team will benefit from closer collaboration with industry and colleagues in adjacent departments, facilitating cross-disciplinary research initiatives and resulting in research going in hitherto unknown directions. The inclusion of modelling (lifecycle, atomistic and finite element) will itself be an important method of interdisciplinary integration of the different technical work packages , allowing dialogue across disciplines and cementing the working relationship across three departments. Postgraduates and staff will gain a better understanding of developments in the field, thus, we will have a direct impact on undergraduate teaching within UoS. The different challenges identified by the research programme will be an opportunity to share both internally and externally new developments and best practice and will introduce non-affiliated scientists to the work of group.

Economy & Society: Industrial partners will benefit from access to facilities and expertise they lack internally, and the involvement of leading UK research groups will give them insight into emerging trends and scientific developments internationally. The aim is to develop new products or processes of commercial value, leading to increased revenue and profits. The process of collaboration de-risks the innovation process, thereby attracting private investment and advancing basic research up Technology Readiness Levels, whilst the knowledge accumulated during and after the funding period will ensure innovation and a strong impact on industrial sectors utilising FMDs. The specific needs of industrial partners will help focus the efforts of the research in an industrially relevant direction, paving the way for future materials research and stronger bonds between research institutions and industry. The use of Life Cycle Analysis and Supply Chain Modelling will give assurance that alternative materials and processing routes offer an environmentally and commercially sustainable route to manufacture, thereby increasing the likelihood of up-scaling and commercialisation.

Our research may impact: i) the electronics sector by funding substitutes for Rare Earths used in Multilayer Ceramic Capacitors; ii) industries such as the automotive sector that would benefit from waste heat reuse via from thermoelectric materials that are less costly and have a greater operational temperature range than existing materials; iii) sustainability of raw materials by eradicating the use of toxic elements (Se, Te ,Pb) and rare earths in functional materials; iv) expanding the 'internet of things' by creating smaller and more performant antennas; v) the environment by improving and simplifying manufacturing, reducing wastage and environmental concerns (e.g. additive manufacturing of FMD) and vi) Commercialisation of A+++ magnetic cooling domestic fridges, by reducing the RE content by >95%, thus reducing the overall manufacturing costs.