Revealing Extrusion Thermal Boundary Conditions for Additive Biomanufacturing

About the project

About the Project Nozzle choice in 3D printing is currently made on cost and durability, not on heat behaviour, even though a nozzle's material governs how much heat reaches the melt during printing. This project treats nozzle material and geometry as design variables for heat and builds the first tool that predicts a material's internal thermal history directly from those choices, before a single layer is printed. A thermal camera can only see the surface of an extruded filament, not its core. In any cylindrical filament, the core stays hotter and cools more slowly than the surface, since heat must conduct outward before it escapes. Recovering the internal temperature from a surface reading alone is a recognised challenge known as the Inverse Heat Conduction Problem. This project develops a novel estimation tool that combines what physics predicts, through the governing conduction equation, with what the thermal camera measures, to produce an accurate estimate of internal temperature. It uses the same operating principle as a phone smoothing a jumpy GPS signal into a steady moving dot on a map, updating frame by frame so the reconstructed temperature is available in real time as the filament cools. The project creates a feedback loop between manufacturing engineering, thermal physics, and polymer science. The rate and extent of cooling set the microstructure and residual stresses within the part, so the reconstructed thermal history is anchored to a defined microstructural state via thermomechanical materials characterisation, validating a mechanistic link between predicted temperature and observed microstructure. The main aim of this project is to reconstruct the internal thermal history of extrusion-based 3D printing and link it to the crystal structure of the finished part. Objectives are to: (a) develop an estimator that reconstructs a filament's internal temperature in real time; (b) quantify the influence of nozzle material and size on the resulting thermal history; (c) establish the mechanistic link between thermal history and microstructure; and (d) explore strategies for thermal process design for biomedical performance. The student will work within the process design for additive biomanufacturing lab, with access to Material Extrusion (ME) technologies, high-speed and thermal imaging, and laser systems, alongside formulation, structure, and process suites available through the University's shared facilities. Training covers manufacturing, formulation, characterisation, scientific writing, and presentation, alongside the practical skills to design, build, and validate printed structures, preparing the candidate for research or industrial careers. This project is based in the Department of Mechanical and Aerospace Engineering (MAE), within a research group working on process-first, design-driven biomanufacturing. Eligibility Applicants should have, or expect to achieve, at least a 2.1 honours degree or a master's (or international equivalent) in a relevant science or engineering related discipline. We are looking for a candidate with a background in mechanical, materials, physics, or a closely related field with an interest in instrumentation, inverse problems, heat transfer, or state estimation. Hands-on experience with thermal imaging, control systems, or DSC is an advantage but not essential. Funding This 3.5 year PhD is for self-funded or externally funded students. The preferred start date is January or April 2027. At Manchester we offer a range of scholarships, studentships and awards at university, faculty and department level, to support both UK and overseas postgraduate researchers applying for competition and self-funded projects. For more information, visit our funding page or search our funding database for specific scholarships, studentships and awards you may be eligible for. Before you apply We strongly recommend that you contact the supervisor, Dr Abdalla Omar ( abdalla.omar@manchester.ac.uk ), for this project before you apply. Please include details of your current level of study, academic background and any relevant experience and include a paragraph about your motivation to study this PhD project. How to apply Apply online through our website: https://uom.link/pgr-apply-2425 When applying, you’ll need to specify the full name of this project, the name of your supervisor, if you already having funding or if you wish to be considered for available funding through the university, details of your previous study, and names and contact details of two referees. Your application will not be processed without all of the required documents submitted at the time of application, and we cannot accept responsibility for late or missed deadlines. Incomplete applications will not be considered. After you have applied you will be asked to upload the following supporting documents: Final Transcript and certificates of all awarded university level qualifications Interim Transcript of any university level qualifications in progress CV Supporting statement: A one or two page statement outlining your motivation to pursue postgraduate research and why you want to undertake postgraduate research at Manchester, any relevant research or work experience, the key findings of your previous research experience, and techniques and skills you’ve developed. (This is mandatory for all applicants and the application will be put on hold without it). Contact details for two referees (please make sure that the contact email you provide is an official university/work email address as we may need to verify the reference) English Language certificate (if applicable) If you have any questions about making an application, please contact our admissions team by emailing FSE.doctoralacademy.admissions@manchester.ac.uk . Equality, diversity and inclusion is fundamental to the success of The University of Manchester, and is at the heart of all of our activities. We know that diversity strengthens our research community, leading to enhanced research creativity, productivity and quality, and societal and economic impact. We actively encourage applicants from diverse career paths and backgrounds and from all sections of the community, regardless of age, disability, ethnicity, gender, gender expression, sexual orientation and transgender status. We also support applications from those returning from a career break or other roles. We consider offering flexible study arrangements (including part-time: 50%, 60% or 80%, depending on the project/funder).

Research areas