Optimising the visibility of polyethylene biomaterials for X-ray imaging

Summary
The chosen PhD candidate will investigate and optimise the material properties of a novel polyethylene composite biomaterial for medical implant applications.

Background
Polymers are one of the fastest growing areas in biomaterials, and polyethylene is one of the most commonly used polymers for medical implants and devices. Over 100,000 polyethylene hip and knee replacement operations are performed in England and Wales each year. Polyethylene is also used for porous facial reconstruction implants, surgical sutures and ligament replacement implants.
Polyethylene implants can be hard to see on a standard X-ray because polyethylene does not readily absorb X-rays. Consequently, positioning of polyethylene implants during surgery can be difficult, and after surgery the implant position and condition cannot be easily determined.
A novel method to modify polyethylene has been invented which can overcome these limitations, but the work is at a very early stage. The process needs to be optimised for medical use and its impact on the material properties of the polyethylene fully understood.

Why apply?
We are looking for a highly motivated candidate with a strong background in materials, engineering, chemistry, or related area to research this exciting new biomaterial. The project will involve a combination of laboratory testing and mathematical modelling work.
By the end of the doctorate the candidate will:
• have extensive knowledge of biomaterial safety and design
• have been trained in a wide range of materials characterisation techniques
• be able to develop numerical models to represent polymeric materials and perform computational simulations to predict behaviour
• be an expert in polyethylene biomaterials
• have presented their work at, at least, one international conference and built up a network of contacts
The candidate will have the opportunity to work with researchers within the medical device industry in the later stages of the project, as well as collaborating directly with surgeons and clinical staff throughout. Furthermore, the University of Bath provides a wide range of training courses, teaching opportunities, and career support for PhD students.

Research centre
Centre for Orthopaedic Biomechanics within the Department of Mechanical Engineering at the University of Bath.

Industrial collaboration
Opportunities to collaborate with the medical devices industry and create contacts internationaly.

Research questions/methods
This research project aims to answer the following questions:
1. What is the influence of different processing parameters on the material properties of the polyethylene composite?
2. How does the processing method work chemically and can this be represented with numerical modelling
3. What is the chemical safety of the polyethylene composite for clinical implant use
4. What is the physical safety of the polyethylene composite for clinical implant use
5. How do manufacturing processes, such as sterilisation, influence the properties of the polyethylene composite