Under the Skin of Ultra-Precision Manufacturing
Project Code: SCE_2023_01
Project Summery
This studentship will contribute to exciting research in advanced robotic manufacture of ultra-precision surfaces on glass materials. These are required for numerous applications in science, medicine and industry. Fine surface processing involves “rubbing” rather than cutting, and is still poorly understood at the fundamental level. The studentship is part of a £1.2m EPSRC-funded project involving four partners to deepen that understanding, by exploring challenging science at the interface between what happens at the atomic scale (molecular dynamics) together with the macroscopic interactions between fluid abrasive media and the tool and glass (computational fluid dynamics). The aim is, for the first time, to combine both types of computer modelling in a comprehensive model of the process, informed by controlled experiments with extensive real-time process-monitoring. The end-game is to combine modelling results with active control to keep processes ‘on track’, reducing manufacturing cost, time and defect-rate.
Background to the research area
The area of work concerns manufacture of precise optics such as lenses and mirrors that underpin a huge range of applications. These include remote-sensing from space, astronomy, photolithography of semiconductor chips, laser-physics, medical diagnostics, security & defense. In the future, energy from laser-fusion may require huge numbers of optics, with repeated refurbishment due to laser damage. A topical application for mass-produced optics is autonomous electric vehicles, requiring cameras, sensors and advanced lighting.
Today, corrective ultra-precise finishing of most glasses and similar materials relies on abrasive-slurry processes, due to sheer practicality and versatility. Given the underlying complexities, results are imperfectly predictable (even on CNC machines or robots), requiring repeated and costly iterations of polish ó metrology. Sometimes, surface quality regresses for no obvious reason, and unexpected artefacts are common. In attempting to resolve this, there is one key factor over which we have neither knowledge nor control:- the micro and macroscopic details of how abrasive slurry traverses the work-piece/tool interface, particularly for complex surfaces. Flow can be laminar or turbulent, slurry-starvation can occur, and at the other extreme, aqua-planing. These all affect speeds/trajectories of the individual slurry particles carried by the liquid medium through the interface with the part, and so the chemical and mechanical interactions with the glass. These in turn drive the instantaneous material removal rates and their inherent variability.
EPSRC has awarded major research grants to a Consortium led by Huddersfield’s Laboratory for Ultra Precision Surfaces at Daresbury. The other partners are the Computational Fluid Dynamics (CFD) group on-campus at Huddersfield led by Prof Mishra, the Molecular Dynamics (MD) group at Liverpool John Moores University, a glass expert at Sheffield Hallam University and the Hartree Supercomputer Centre at Daresbury. The objective is to create the world’s first multi-scale model of ultra-precision abrasive processes, demonstrating predictive capabilities that promise to be the key to improve the predictability and quality of robotic surface-finishing processes. The broad scope of the overall EPSRC project involves:-
Context for the student research – the new EPSRC-funded project
- Mechanistic understanding of the physical-chemical contributions to glass polishing
- CFD modelling to predict microscopic slurry-particle velocities and trajectories, as input to:
- MD modelling, to predict removal-rates at nano-scales
- Combined in development of a macroscopic model to predict removal in real-time
- Accommodating real-life processing-geometries (flat – to – complex surfaces)
- Supported by gathering extensive real-time process-data (forces, torques, acoustics, abrasive-slurry conditions) and post-process data (surface-metrology) on a range of sample parts processed under different conditions.
- With machine learning algorithms applied to the accumulated data-base to complement and reinforce modelling
Opportunities for the student’s research contribution
We are now seeking a student to work under the University of Huddersfield within the multi-institute, multi-disciplinary project team. The exact role of the student is very flexible, but needs to be an area of research that is relevant and useful to Huddersfield’s work on the project, of interest to the student, and within the student’s capabilities.
The preferred – but not the only acceptable – area of work would focus on the exciting opportunity presented by the interface between i) hands-on experimental work, data capture & interpretation, and ii) helping to develop and verify a process-model that can predict material removal, given real-time sensor data, modelling results and artificial intelligence.
Qualifications and background
We are considering candidates for a funded PhD Studentship, which is open to individuals meeting academic requirements who are eligible for UK home tuition fees. There is considerable flexibility in the specific area(s) in which the successful candidate will contribute to the EPSRC project described above, which in turn will influence the appropriate qualifications and experience. Overall, the project would suit a Mechanical Engineering or Physics graduate with computational, modelling or experimental skills. Degree course-content in Materials Science would be advantageous.
The project will include a significant element of adventure, and the successful candidate will be prepared to tackle unexpected problems, be inventive and willing to stretch beyond past fields of experience. Good written and verbal communication skills in English are essential. Computer literacy is a requirement, alongside a willingness to learn specific modelling codes depending on the detailed project. For the preferred area of work (as above) general competence in experimental technique is required, and training will be provided for safe and effective use of CNC and robot polishing platforms, supporting software and metrology instrumentation.
The studentship will be physically located within the stimulating environment of the National SciTech Daresbury Science and Innovation Campus (near Warrington). This where the Huddersfield Laboratory for Ultra Precision Surfaces is based, a few minutes’ walk from the Hartree Supercomputer Centre.
