April 2011

successful seminar – ‘Using lasers to modulate biological cell response’

Paul Stewart
Dr David Waugh giving an open seminar

Summary
Wed 6th April 2011 @ 2:00p.m. – 3:00p.m. Lincoln School of Engineering Open Seminar Series. Dr. David Waugh gave an open seminar about ‘Using lasers to modulate biological cell response’ in one of Lincoln:Engineering’s seminar rooms.

Abstract

With an aging population there is an ever growing demand on medical facilities, especially with regard to biological implant technology. Laser surface treatment offers a unique way of tailoring surfaces to manipulate cell response in order to reduce and predict clinical failure. This open seminar will give you an insight into the multidisciplinary research carried out by Dr. Waugh, a Research Fellow in the Lincoln School of Engineering. The seminar will discuss work in the field of laser-modified wettability characteristics and how they can be employed to determine the biofunctionality of a given material. Furthermore, the future for this research will be discussed including potential use of this technology in stem cell growth and manipulation.

Dr. David Waugh Ph.D., MSc. MPhys, MIET, AMInstP is currently a Research Fellow at the Lincoln School of Engineering. He is currently undertaking a feasibility study modelling and simulating a number of techniques to harness the kinetic energy from landing aircraft, under the supervision of Prof. Paul Stewart.

In addition, Dr. Waugh is furthering his Ph.D. research into the application of lasers in life sciences. This involves the laser surface treatment of biomaterials, specifically polymers, to modify the surface topography and surface chemistry to enhance biological cell growth. This is carried out in the endeavour to counter the failure rates of biological implants so that the need for unnecessary corrective surgery is considerably reduced.

Dr. Waugh has also carried out significant studies into the modification of wettability characteristics of laser surface-modified polymeric materials. With this in mind, he endeavours to quantitatively link the wettability characteristics of a material to its bioactive nature in the hope to give clinicians a platform from which tailored biomaterials can be produced. This would allow clinicians to have the ability to confidently predict cell response to a specific material.

His Ph.D. entitled “Laser surface treatment of nylon 6,6 for the modification of wettability characteristics and subsequent enhancement of osteoblast cell response” was carried out in the Wolfson School of Engineering at Loughborough University, under the supervision of Dr. Jonathan Lawrence. His MPhys. and MSc. in Physics with lasers and optics was carried out at the University of Hull.

Dr. Waugh actively publishes his work through books and international journals. In addition, he has attended and presented at a number of national and international conferences such as the International Congress on the Applications of Lasers and Electro-Optics (ICALEO). Furthermore, he has been a reviewer for a number of academic journals such as Lasers in Engineering, Surface and Coatings Technology and the Institution of Mechanical Engineers, Part C; Journal of Mechanical Engineering Science.

The Lotus Free Piston Engine project story part I

Paul Stewart
Graham Smith, Technician in Aeronautical and Automotive Engineering at the University of Loughborough brings in the new engine

The idea to develop a free piston engine has a long history, mainly focusing on two-stroke designs with a combustion chamber at each end of a linear motor generator. the main idea is to remove the physical constraints imposed by conventional crankshaft based engines, reduce the mechanical losses to improve the engine efficiency, and to introduce elements of piston trajectory control to allow advanced combustion control.

As if that wasn’t challenging enough, Jamie Turner of Lotus Engineering and I had the idea of pushing the envelope even further, to create a single combustion chamber, four-stroke design. This developed from the fact that two-ended designs are generally constrained to operate via an oscillating principle akin to simple harmonic motion for increase efficiency. In our view, we wanted to push the technology of the possible even further, and design what was originally called the Lotus Active Crank Train (ACT) and eventually became the Zero Constraint Free Piston Energy Converter.

We originally applied to the EPSRC ‘Adventure Fund’, but the application was rejected on the grounds that the proposal was ‘too adventurous’! The EPSRC however invited us to re-submit, and the project became…

EPSRC Grant: GR/S97507/01 ‘Zero Constraint Free Piston Energy Converter‘
PI: Paul Stewart. Co-Investigator: D. Howe. (University of Sheffield) Collaborating University: Dr Rui Chen, Dept. Aeronautical and Automotive Engineering, University of Loughborough UK. Collaborating Company: Lotus Engineering, Consortium Project Manager: Paul Stewart.

P. Stewart: £326,00, R. Chen £260,000, Lotus Engineering Contribution: £330,000

Rui Chen wondering what he has got himself involved with!

I was a Junior Lecturer at the time in the Electrical Machines and Drives Group at Sheffield University. I needed an engines/combustion collaborator, and since I had worked at Loughborough as a Post-doc, searched their web-site and approached Dr Rui Chen who was then also a Junior Lecturer (now Professor of Low Carbon Power Engineering) in the Department of Aeronautical and Automotive Engineering at the University of Loughborough. This was the start of a research relationship and friendship which lasts to this day.

In order to ‘de-risk’ the project, the free-piston was originally tethered to the crankshaft of a General Motors 1.8l engine so that we could conduct our initial development in relative safety. The engine as delivered from lotus is pictured above, the free-piston part (nick named the ‘rocket launcher’) is the tube and cylinder head sticking up from the GM crankcase. In the next part of the story, we get it running, and discover we can look at some hitherto unattainable fundamental aspects of combustion.

Modifications to Lotus Free-Piston engine complete

Paul Stewart
The free-piston engine at Lotus waiting for collection

Our free piston engine has had it’s major modifications completed by Lotus and is now ready for one of us to go over to Norwich and pick it up. The engine has had a new 25kW linear motor/generator fitted. When we get it back to our labs in Lincoln, Control Techniques will be coming over to re-commission the electrical system and load dynamometer. After this we will be continuing our research into novel combustion strategies and power plants for hybrid electric vehicles.

A controlled migration genetic algorithm operator for hardware-in-the-loop experimentation

Paul Stewart

Lotus free-piston experimental engine

A controlled migration genetic algorithm operator for hardware-in-the-loop experimentation

D. Gladwina, P. Stewartb, , and J. Stewartb

a Department of Electronic and Electrical Engineering, University of Sheffield, Mappin St. Sheffield S1 3JD, UK

b School of Engineering, University of Lincoln, Lincoln LN6 7TS, UK

Engineering Applications of Artificial Intelligence
Volume 24, Issue 4, June 2011, Pages 586-594

doi:10.1016/j.engappai.2011.01.006

Abstract

In this paper, we describe the development of an extended migration operator, which combats the negative effects of noise on the effective search capabilities of genetic algorithms. The research is motivated by the need to minimise the number of evaluations during hardware-in-the-loop experimentation, which can carry a significant cost penalty in terms of time or financial expense. The authors build on previous research, where convergence for search methods such as simulated annealing and variable neighbourhood search was accelerated by the implementation of an adaptive decision support operator. This methodology was found to be effective in searching noisy data surfaces. Providing that noise is not too significant, genetic algorithms can prove even more effective guiding experimentation. It will be shown that with the introduction of a controlled migration operator into the GA heuristic, data, which represents a significant signal-to-noise ratio, can be searched with significant beneficial effects on the efficiency of hardware-in-the-loop experimentation, without a priori parameter tuning. The method is tested on an engine-in-the-loop experimental example, and shown to bring significant performance benefits.

Keywords: Genetic algorithms; Hardware-in-the-loop; Migration; Response surfaces; Engines