YU

The Fellow and his team are seeking to develop a ground-breaking electronic device named the multimodal transistor. Arising from more than a decade of experience in unconventional device design, it allows for entirely new applications such as hardware learning, analog computation and control, while being energy efficient and easy to fabricate. News headlines in electronic devices usually hail developments in nanoscale billion-transistor chips, yet there are major opportunities for innovation in display screen technologies, in which the requirement of fabricating circuits at low cost over large areas, and not ultimate miniaturization, is prevalent. Existing fabrication facilities are now partly being repurposed for emerging large area electronic (LAE) applications: microfluidics, lab-on-a chip, ubiquitous sensors or wearable electronics. LAE usually contain large arrays of relatively simple circuits with few transistors, as areal performance variations impede the fabrication of complex circuits. Incremental progress in LAE is constantly achieved through processes and equipment improvements, and by using new materials with superior properties, both with large capital investment. The Fellow proposes a major step in LAE development, a radical new device design: the multimodal transistor (MMT). The MMT enables new ways of designing electronic circuits for efficient analog operations (amplification, data conversion, analog computation), control and feedback, and ultimately, LAE circuits capable of learning (hardware AI), so far impractical with conventional devices and techniques. Functionality is achieved using energy-efficient circuits of minimal complexity, allowing environmentally friendly fabrication at low cost. By greatly expanding the design possibilities, while being entirely compatible with conventional LAE fabrication, MMT circuits extend the usable lifetime of current manufacturing technologies, maximising the return on investment, and can accelerate the uptake of emerging processes such as 2D semiconductors and spatial atomic layer deposition. The Fellow's team will leverage our long experience in device design and the complementary capabilities of our international partners to design, fabricate and test devices and circuits using vacuum processing and additive manufacturing in conventional and emergent semiconductor systems, supported by state-of-the-art numerical simulation. The team will use their extensive collaborator networks to seed the development of a new electronic design paradigm. As this is an enabling technology, its applications span fields from disposable medical diagnostics and crop monitoring to autonomous vehicle control, new forms user interfaces and immersive entertainment environments, with substantial long term economical and public benefits for the UK and the world. The implications of the novel functionality, such as hardware AI and autonomy, will be a constantly considered. Stakeholders will be involved in shaping the research through cross-disciplinary workshops, online engagement and science festival participation. The focus on people will further include: continuing a decade-long tradition of training, mentoring and involving school students in the Fellow's research; supporting a strong start to the careers of young researchers involved through mentoring, independence and due to the ground-breaking nature of the work; and incorporating the findings into Surrey's teaching curriculum to increase our graduates' employability. The Fellowship will accelerate the Fellow's growth as an international technical and thought leader, while retaining valuable skills, intellectual property and know-how in the UK at a time of global uncertainty. A Fellowship is the optimal funding route, allowing full commitment to advancing this trailblazing design paradigm, within a robust structure and collaborative environment which includes world-leading research facilities and support networks.

Disordered networks are at the heart of a multitude of materials with functional properties where examples range from the glasses used in optical communications technology to the role of water in geological processes. Establishing the network structure, and its relation to a system's physico-chemical and opto-electronic properties, is a prerequisite for making new materials through the principle of rational design. Here we tackle this issue by using an integrated approach to investigate the fundamentals of basic networks, using pressure to manipulate the bonding and network topology. Oxide and chalcogenide glasses along with water will be investigated, the systems chosen to be exemplars of network forming materials with different bonding mechanisms. The contrasting bonding schemes confer the networks with different characteristics and have the potential for making modified materials with tailored functional and structural properties. Applications include the recovery to ambient conditions of materials with novel characteristics, sequestration of the green house gas CO2 by geological fluids, and the effect of rare-earth clustering on the photonic properties of glass. The inherent disorder of liquid and glassy network structures is a blessing, in delivering materials of unique scientific and technological importance, but is also a curse, in providing complexity on the atomic scale. The method of neutron diffraction with isotope substitution (NDIS) has played a pivotal role in unravelling the mysteries of disordered materials since it allows access to the so-called partial structure factors i.e. to the maximum information that can be extracted from a diffraction experiment. Over the last 3 years, Bath has led an initiative to develop the techniques for measuring accurate neutron diffraction patterns for glasses and liquids at high pressures using the Paris-Edinburgh press. Thus, the time is now ideal to exploit the NDIS method to make in situ high pressure and temperature investigations of structurally disordered materials. We intend to investigate the mechanisms of structural collapse in three classes of system with different bonding schemes and concomitant network properties, namely oxide glasses (GeO2), chalcogenide glasses (e.g. GeSe2, As2Se3, AsSe) and water. These particular systems are chosen because they are archetypical materials for the study of disordered networks e.g. they either show or are anticipated to show polyamorphic phase transformations in which there is an abrupt change in their structure and physical properties with change of pressure and/or temperature. In the case of the chalcogenide glasses, the large structural variability leads to the possibility of recovering new materials with novel functional properties to ambient conditions. The structure of two types of adapted networks will also be considered, namely salty water and rare-earth alumino silicate glasses. In the former, the experiments will be made under the high pressure and temperature conditions relevant for geological fluids where applications include the sequestration of CO2. In the latter, the phenomenon of rare-earth clustering will be investigated with a view to controlling the separation of nearest-neighbour ions and hence the optical properties of these materials. Complementary information will be provided, where applicable, by NMR (Warwick), high energy x-ray diffraction, EXAFS spectroscopy and other experimental techniques. The NMR work will include well established nuclei (27Al and 29Si for the alumino silicates) but will extend the boundaries of the method by using 17O, 73Ge and 77Se. A combination of isotopic enrichment and NMR enhancement schemes will maximise the amount of structural information that can be extracted by using these nuclei as probes. Importantly, the experimental work will be enriched and complemented by molecular dynamics simulations made in collaboration with groups in Oxford, Cambridge and Strasbourg.