Theoretical physicists don't usually earn thank-yous from the parents of children with cystic fibrosis. But then Erik Luijten isn't your typical theoretical physicist.

Luijten and collaborator Gerard Wong are Beckman Institute researchers whose 2007 paper provided new insights into fighting bacterial infections in cystic fibrosis patients. In a Proceedings of the National Academy of Sciences (PNAS) paper, the pair demonstrated through a combination of experiments and computer simulations why long-term bacterial infections, a leading cause of death for those afflicted with cystic fibrosis, were able to resist current treatments while also describing a model for the possible future development of antimicrobials that would fight long-term infection.

Luijten, a member of Beckman's Computational Multiscale Nanosystems group and Associate Professor in the Department of Materials Science and Engineering and the Department of Physics, said that after news of their work was made public, he heard from parents of cystic fibrosis patients from across the country.

"It was interesting because when we do other, what I would call exciting projects, the feedback is limited or subdued," Luijten said. "Here I received e-mails after the press release came out from parents sending me pictures of their children, saying 'my child has cystic fibrosis and this (discovery) is so fantastic,' which of course never happens normally. They wrote 'if you're ever in my state stop by,' that sort of thing. In that sense it felt really good."

Luijten's contribution to the project was his expertise in the area of computer simulations of soft materials, specifically complex fluids. As he did in the cystic fibrosis project, Luijten takes the work of experimental researchers like Wong and adds the element of dynamic computer simulation in order to gain a better understanding of the workings of complex fluids. It was an area he was hardly familiar with before coming to the University of Illinois.

"When I came here seven years ago there were several people who were doing really exciting experimental research in this area," Luijten said. "So I was very intrigued by the results that they described and I thought, hey, with the sort of simulation techniques which I have mastered and used for a lot of different problems, I could also try to understand these types of systems."

So Luijten created a new research path for himself, based upon his knowledge of computer simulations and his excitement over the work of experimentalist researchers like Wong, and fellow Beckman colleagues Paul Braun, Jennifer Lewis, and Steve Granick.

"I try to find clever ways of using computer simulations to understand the systems that the experimentalists study," Luijten said. "Really, the second that I came here I got so much exposure to exciting topics and to colleagues who were excited about what they are doing.

"Coming here has stimulated me in so many ways - it completely changed my research focus. It is unrelated to anything that I did before. I am a person who likes change a lot; I always like to be stimulated. I don't like to make things easy for myself."

Luijten certainly didn't make things easier on himself by shifting his research focus or by taking a road-less-travelled approach.

"I was not truly aware of this type of research (on complex fluids) and I jumped into it not realizing how complicated the simulations would become," he said. "We try to understand from a mechanistic point of view what is going on in these systems, how can we explain the experimental results that are reported, given the ingredients or the components of these systems."

In order to do that, Luijten had to break some new ground in applying his computational methodologies to biological processes.

"In going this whole other direction with my research I realized that many of the existing simulation methods were just not adequate for studying these sorts of systems (complex fluids)," he said. "The ideas are correct but the systems are so complicated that it would take forever. So I always try to be smart about how to address a particular system or problem that I encounter. We developed several new simulation techniques that have turned out to be extremely powerful."

Luijten's approach is to create computer simulations that have the same components an experimentalist finds in a lab experiment. The goals, as his research summary states, are to "first, understand experimentally observed phenomena from the underlying microscopic features of a system, and second, to test the predictive value of analytic theories describing these systems. The insight thus gained allows the prediction of yet unknown properties of materials and the design of new materials."