PhD Studentship - SHARP-ID – Shape and Rigidity Profiling via Density-Induced Banding of Red Blood Cells

Dr Alexis Darras

Research Project

Centrifugation of Red Blood Cells (RBCs) in continuous density gradient has recently been suggested for detecting pathological alterations [1]. Interestingly, band patterns form along the gradient. This project builds on recent findings showing these patterns result from a balance between buoyancy and aggregation forces [2]. It aims to optimize detection of RBCs with altered mechanical properties by refining non-linear density gradients.

The goal is to improve reproducibility and sensitivity of band formation to detect mechanical changes: linear gradients are sensitive but poorly reproducible; sigmoidal gradients are stable but lack sensitivity. We aim to design custom gradients combining both advantages.

Programmable syringe pumps will generate arbitrary gradients from two density solutions. These will be tested on RBCs with controlled shape and rigidity variations, and quantified using confocal and atomic force microscopy. Band patterns will be analyzed via automated image processing and classified using AI trained on simulated and experimental data.

This approach offers a scalable, low-cost diagnostic tool for diseases like sickle cell anemia and malaria, with potential for treatment monitoring and early detection.

This project benefits from the interdisciplinary environment at UoB, drawing on expertise from Prof. Ash Toye and Dr. Jan Frayne in red blood cell biology. Clinical insight will be provided by Dr. Claire Rice and Dr. Sanne Lugthart, specialists in inherited blood disorders. The theoretical components will be supported through collaboration with Francesco Turci and Simon Hanna, and access to the Isambard-AI supercomputer. Overall, this environment offers scientific excellence and strong pastoral support within the vibrant research culture of the School of Physics and the EngBioCDT programme.

How do I apply?  

You will need (1) a CV, (2) a Personal Statement, which is a one- to two-page document introducing yourself and outlining your motivation for PhD research, and (3) a transcript of any qualifying degrees (completed and/or underway). 

Applicants will be assessed on merit, and interviews will be held for shortlisted applicants.

You need to apply through the University of Bristol application system at, the apply button above. Please select Physics PhD on the Programme Choice page. The School of Physics supports Diversity and Equality, and we invite all eligible candidates to apply. We encourage applications from under-represented groups. We hold a Bronze Athena Swan award and a Physics Juno Champion award.

What are the candidate requirements?

A first degree in physics or a related subject, normally at a level equivalent to at least UK upper second-class honours, or a relevant postgraduate master's qualification. Please see

English language requirements

If English is not your first language, you need to meet English Language Profile F. Further information about this can be found here: English language requirements | Study at Bristol | University of Bristol

Admissions Statement: PhD and MSc by Research Physics Admissions Statement

Contacts and further information

Please contact the Bristol Physics Graduate School 

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