Dr Nathan Quinlan, a senior lecturer in mechanical engineering at NUI Galway, discusses his attempts to unlock the secrets of fluid dynamics.
Last month, a Galway-founded company called Aerogen announced that it was going international with the opening of a German commercial headquarters in the town of Ratingen, in what was another sign of the west coast’s medtech prowess.
Aerogen is a major player in the aerosol drug-delivery sector, with around 5m acute-care patients worldwide using its technology.
Working with the company for the past 15 years is Dr Nathan Quinlan, a senior lecturer in mechanical engineering at NUI Galway and an investigator at the Cúram centre for research in medical devices.
After picking up his degree in mechanical engineering and a master’s in aerodynamics of advanced aircraft engines at NUI Galway, he went on to develop a computational model to predict the performance of a propfan, a highly efficient hybrid of a propeller and jet engine.
His breakthrough into medical devices came following his doctorate at Oxford University working on an “extraordinary” device for a needle-less injection, which uses a gas flow to carry powdered drugs.
What inspired you to become a researcher?
I remember a specific moment, sitting in a lecture about the dynamics and mathematics of rockets. It’s a problem that seemed hard at first, but unravelled when approached the right way. It hit me with great clarity that Newton’s laws can tell you everything about motion. Using these very simple fundamental rules, you could build up a model or a prediction of almost anything that moves.
From there, research seemed to be a way to spend time understanding those fundamental building blocks and putting them together. Research is constant learning, and the results of that work could help to make useful things.
Can you tell us about the research you’re currently working on?
At the Cúram centre for research in medical devices, I work on unique technology developed by Aerogen, a Galway company that leads the world in aerosol drug delivery.
The key to its success is its capability to generate huge numbers of very small droplets of liquid drug very consistently. Because the droplets are small, they can travel deep into the lung. Droplets are formed at microscopic holes in a plate that vibrates 128,000 times per second. We are creating computational models of the liquid medication flowing at scales of microns and microseconds.
This will give us insights into the operation of the technology, and help it to develop in future. For example, we can simulate design changes to predict their effects before they are implemented.
In your opinion, why is your research important?
‘Fluid dynamics’ is the single phrase that best summarises what I do. Fluid dynamics – including both liquids and gases – is everywhere.
Often it’s invisible, but it’s vital to the flow of blood in the human body, keeping aircraft in the air, keeping computers cool and wind turbines spinning. Many medical devices exploit it, from artificial organs to lab-on-chip systems.
On the negative side, however, it plays a role in some cardiovascular disease, accounts for a lot of the energy consumed by transport, and can be destructive in storms and other forces of nature.
Fluid dynamics is vital to life and ubiquitous in engineering, but it still holds mysteries.
What commercial applications do you foresee for your research?
Our collaboration with Aerogen is an example of a project with direct commercial application.
Our work will feed into the design of future versions of the technology for the delivery of novel therapeutics. The computational methods that my groups develop for flow simulation have applications in simulation of biological processes and medical devices, and many other fields of engineering.
In the longer term, the software that we develop will be exploited either as a commercial or open-source release.
What are some of the biggest challenges you face as a researcher in your field?
The need to master the tools (computing and experimental techniques), and sometimes to make the tools to answer the research problem. Sometimes, the tools themselves become an avenue of research.
Finding the time, and the self-discipline, to really finish off a piece of work and write it up before moving on to the next shiny, new thing.
As problems go, these are really nice problems to have!
Are there any common misconceptions about this area of research?
Engineering in general is not well understood as a profession, perhaps because its variety is so hard to sum up in a single sound bite or picture.
We have to keep shining a light on the diverse things that engineers do. An engineering education isn’t a training for any one career, but a way of thinking, of using scientific understanding to create amazing things.
Most of all, we have to shake off the insidious notion that engineering isn’t for girls. We’ve looked at the numbers in NUI Galway and found that although women make up a smaller part of the engineering student population, they get proportionately more of the high grades and study higher degrees.
What are some of the areas of research you’d like to see tackled in the years ahead?
There are still huge questions about what happens in turbulent blood flow. True turbulence is a hard problem in ordinary fluids because it’s chaotic at large scale and all the way down the microscale. When viewed at everyday scales, blood acts like a slightly more viscous version of water – however, it’s made of highly flexible cells, suspended in liquid but closely packed.
If we could understand how turbulence works in that environment, and how cells respond to it, it would be a big step forward in the understanding of cardiovascular disease and the design of implants such as stents and ventricular assist devices.