Dr Marion McAfee
PEM Principal Investigator
Lecturer in Engineering Dynamics and Control
Area of Expertise: Sensing, Modelling, Optimisation and control Systems particularly in Manufacturing
Dr McAfee has been a lecturer in the fields of Engineering Dynamics and Control since 2006. Her research interests are in sensing, modelling, optimisation and control of systems, particularly in manufacturing. She has a particular interest in the development of soft sensing technologies. She is a Principal Investigator in the Precision Engineering, Materials and Manufacturing Strategic Research Centre (PEM SRC) and the Mathematical Modelling Research Group.
As a researcher in engineering, many of Dr McAfee’s research projects have involved industrial collaboration – particularly in the manufacturing domain. Selected industrial research projects which have led to process improvement or new industrial products are outlined below.
Development of Next Generation Injection Mould Tooling (AbbVIE, Sligo). This project is currently ongoing and aims to develop smart, 3D printed injection mould tools with embedded sensors for medical device manufacturing. This will greatly enance process QA and process control. I-Form Spoke Project
Medical Implant Research
If you have a clogged artery or a damaged joint, your body may need some help to fix it. And if that help comes in the form of an artificial implant, wouldn’t it be ideal if the implant could simply break down over time and get safely absorbed by your body?
Bioresorbable materials have been used for a whole host of different devices, such as stents, and they are increasing in popularity. Over time, the material breaks down into carbon dioxide and water and lactic acid and are excreted through natural biological processes.
Implanted materials can be used to deliver drugs in hard-to-reach places, such as inside arteries or in the eye, and they can also be used in bone-fixation screws. However, the manufacturing of such devices is difficult as they tend to degrade under the temperature and pressure conditions required to form the product. Dr McAfee led a collaborative European project to accelerate the development of process monitoring and control technology for the production of bioresorbable medical implants. This led to the development of a novel production process for a bioresorbable tissue scaffold which had production rates six times higher than their existing process and with reduced scrap rates. This enabled the company to develop a new, larger implant which had previously been too expensive to produce. Finally, novel formulations for future products were developed which had better biocompatibility properties and are significantly cheaper to produce. (https://cordis.europa.eu/project/rcn/111051/)
The €1m project, which IT Sligo co-ordinated, involved several partners, including Scaffdex, which makes resorbable ‘spacer’ devices to implant into joints in the hands and feet of people with arthritis – the device is gradually replaced by the patient’s own cells and tissues.
UV-Vis technique for on-line monitoring of additive particle dispersion in polymer extrusion (Innovative Polymer Compounds, Westmeath). Dr McAfee was Principal Investigator (PI) for the development of on-line process monitoring tools for production of medical polymer compounds. Her team developed a UV-Vis spectroscopic method for detecting micro-scale particle agglomeration in production of medical polymer compounds. The method was tested in situ in a commercial medical polymer compounding plant (Innovative Polymer Compounds Ltd.) and found to be sensitive to even small changes in the average size of additive particles. The ability to detect particle agglomeration on-line is a major step-forward for the company who previously had to do this off-line by preparing a sample of extrudate for optical microscopy.
Multi-lumen medical tubing made from filled polymers
Development of an industrial control system for the regulation of polymer viscosity in processing of recycled HDPE (Cherry Pipes Ltd, NI). Dr McAfee led two work packages in the EU FP7 UltraVISC project (2009-2011) which involved the development of technology to control the production of pipes made from recycled HDPE (Cherry Pipes Ltd.). She was the PI responsible for the technology for monitoring and regulating the melt viscosity and the product dimensions. Variations in the raw material mean the process is difficult to control and prior to the project there was a scrap rate of 7% due to unacceptable variations in pipe diameter, in part caused by variable polymer viscosity during processing. A novel instrumented hopper design (TSM Controls) was implemented together with a novel viscosity monitoring and control system. This was installed in the plant in 2012 with a significant reduction in scrap rates.
Internal Cooling System for Rotational Moulding Process (SPI Play Ltd. and Balmoral tanks Ltd. UK) Dr McAfee was coPI on an industrial project (FP6 Research for SMEs Associations programme) to reduce cycle times in the rotational moulding process. She co-supervised a PhD student to develop a controlled water-spray internal cooling system which used the latent heat of vaporisation to rapid cool the parts without warping or otherwise damaging the product. The system also improved the impact properties of the device and was installed in commercial production facilities.