Atmospheric Pressure Plasma for Surface Engineering Applications

This project will build on the knowledge and capabilities obtained in the Surface Engineering and Precision institute (SEPi) over the last decade, in close collaboration with industrial supervisors from the MTC. To achieve the project aims stated above the following objectives will be fulfilled:
Identification of the optimised plasma delivery system and best chemistry for metal processing: A comprehensive literature review and consultations with industrial practitioners will help to decide upon specific characteristics of the plasma delivery system such as; the type of nozzles, the targeted metal materials (e.g., Ti), reactive gas composition (e.g., CCI4) and flowrate. Once these basic choices have been made, key operational parameters, such as power and surface distance, will be optimised. The results will be compared to those obtained for optical substrates, to assess the effects on the metal work-piece.
Metal-etching footprint characterisation: The cross sectional profile of etched trenches on a sample surface and the factors affecting this profile will be investigated. As etching is expected to follow Arrhenius equation, particular attention will be paid to the effect of the surface temperature. Measurement techniques such as pyrometry and fibre Bragg grating will also be studied for the characterisation of the sample surface temperature exposed to the plasma plume. Following these assessments, investigations will focus on the effects of overlapping trenches (PSD analysis).
Modelling the thermodynamic and aerodynamic properties of the radio-frequency induction coupled plasma and the metal-etching process: Previous Cranfield University PhD projects from Drs. Yu and Castelli have established numerical modelling of the plasma and the description of the etching profiles for Si-based samples. The same methodolo,:y will be applied to the metal-etching process in order to obtain in-depth understanding of the plasma processing for metal surface engineering.
Design of experiments of Plasma metal etching: Based on the results in (2) & (3), correlations between input parameters and output quality will be established. Consequently, dwell-time algorithms and motion tool-path design will be implemented to achieve a deterministic machining process. Finally, surface qualifiers such as form accuracy, roughness and processing time will be characterised and compared to those of alternative methods.

The major beneficiaries of the research outputs from the Centre for Doctoral Training in Ultra Precision (CDT-UP) include UK manufacturing companies (especially SMEs), the University partners, including the two primary universities, and the wider UK universities engaged in Ultra Precision research, in addition to society in general. Benefits will be realised in terms of:- increased economic activity in the field of UP through spin-out companies, licensed technology outputs, and the realisation of new products made possible with the application of UP manufacturing capabilities; greater knowledge of and a wider appreciation of the technical capabilities of UP systems; the provision of highly trained PhD level personnel for UK industry to spearhead new ultra precision competencies; and the creation of new products for the market based on UP competencies and technologies, which have the potential for significant societal impacts in areas such as health-care, transport, energy generation, and communications.
The importance of ultra precision manufacturing to the UK economy and the key issues and barriers to economic success are highlighted in the main proposal which demonstrate the central role of ultra precision manufacturing technology in ensuring economic growth. Many emerging sectors and next generation products will demand ultra precise components (nanometre, and sub-micron-level tolerance). To date semiconductor systems, and microsystems (optical, mechanical, or electrical) use complex expensive process steps in their production. Such extensive process chains are needed to create even initial pre-production prototypes. This issue has become a significant barrier to SME's realising their innovative products requiring UP. We aim to develop ultra precision manufacturing technologies that will offer precision capabilities, with a reduced level of capital investment compared to traditional semiconductor fabrication routes. These include:- wide area roll-to-roll printing of electronic devices, optical films, and structured surfaces; novel micro machining technologies for the production of 3-dmensional components such as micro-mechanical elements, embossing and injection mould tools, and micro-embossing tools.; direct writing and accretion of nanoscale features of semiconductor materials for low cost prototyping of micro and nano systems.
Manufacturing success requires not only the generation of new knowledge, it also requires people with the ability to invent and innovate. The education and research training of the CDT-UP will be developed in partnership with the new EPSRC centre for Ultra Precision, a wide range of industrial collaborators, and other UK universities working in the field of UP. This leading educational centre will respond to both the industrial need of UK companies, and the educational development strategies of UK universities, in developing the people with the technical capabilities necessary to move from the inventive steps to innovation platforms, thereby increasing the potential for wealth creation in the UK. We ensure that UK manufacturing can meet the future technical and business challenges needed to compete globally. The potential of the UK's innovation capacity to create new high-end manufacturing jobs is significant. Maximising this wealth generation opportunity within the UK will however depend on successfully realising next generation innovative production systems. Without relevant production research, r&d infrastructure, and an effective technology supply chain, there will be a limit to the UK's direct employment growth from its innovation capacity, leading to a constant migration of UK wealth creation potential into overseas economies. CDT-UP will develop a significant number of highly trained manufacturing engineers who will be essential to provide the leadership necessary to drive UK high value manufacturing forward and provide the vision for future prosperity.