Freshly arrived from Brown this summer, Bill Curtin, the new director of the Institute of Mechanical Engineering, is a multi-talented scientist. A physicist by training, during his career he has been just as comfortable working in mechanics or in materials science. His goals are to encourage synergies within his institute and to take risks.
Restricting oneself to only one discipline is definitely not Curtin’s motto. The new director of EPFL’s Institute of Mechanical Engineering (IGM) is a staunch defender of multidisciplinarity. He states: "When you immerse yourself in a discipline other than your own, you have a different outlook to that of the experts, and this can enable the emergence of new ideas." This is a principle that the physicist has already tested and which he continues to apply for his research, which concerns multi-scale modelling – from atomistic to continuum scales – for various mechanical problems, like fracture and fatigue of materials. (see technical description further down)
From Brown to Virginia Tech, via BP
His career path is a testament to his tendency towards multidisciplinarity. After gaining a BS and an MS in Physics at Brown University, then a PhD in theoretical physics at Cornell University, he left the academic world for industry, working in the Applied Physics Group of BP (British Petroleum). There he addressed hydrogen storage in amorphous metal alloys and the mechanics of fiber-reinforced composites, to guide development of materials with enhanced performance. After seven years at BP, he came back to the academic world, but with less focus on physics. He settled down at Virginia Tech and for five years held a position as professor attached to two engineering departments: materials science and engineering mechanics.
He joined the solid mechanics group at Brown in 1998. "Brown had an international reputation in solid mechanics. It was the best place for the type of research I wanted to conduct", explains the professor. At that point, he had the necessary skills to study the behaviour of materials at all levels. "I had studied phenomena at the atomic and quantum levels during my PhD and at BP, I had modeled composites on the continuum scale. When I arrived at Brown, I was able to leverage these competences and work on multi-scale modeling."
Analyzing, predicting and creating
Curtin is now concentrating on several paths of research that combine physics, materials science, and mechanics: understanding how materials deform, fracture, and fatigue, improving existing materials and also predicting properties of new materials: metal alloys and composites containing carbon nanotubes.
1.Fatigue and Fracture
"Fractures and fatigue happen for pretty much everything. Take the paper-clip, for example," explains the professor. "If you bend it a number of times, you notice that, at the bend, the metal becomes faded, and then eventually breaks. First there is the metal fatigue, and then final fracture. These are the phenomena that we are studying at different levels. To understand why the paper-clip breaks, it’s important to observe not only the phenomena at the continuum scale, but also the behaviour of the atoms at the crack tip," he notes. And what happens in the paperclip is happening in metal components used in industries ranging from cars to aircraft, from machinery to turbine, from generators to watches.
"New nanocomposite materials could be interesting for the aerospace industry, the production of jet engines, or in designing the leading edges of wings in high-speed aircraft, where the heat is intense."
2. New materials
In parallel, Curtin is studying the possibility of modeling the creation of new materials, and precise predictions of the robustness of the new materials, as well as determining the moment when they will break."We call it ‘computational alchemy’," comments the professor. "Basically, we are looking to improve existing materials, by studying questions such as: if we add an element from the periodic table to Aluminum, does it enable us to strengthen the material, without altering its ability to deform easily into complex shapes?" This research is supported by the car manufacturer General Motors, who would be very interested in using such a material for the production of doors, hoods, and other components.
3.Create new materials for aerospace industry
Professor Curtin is also working on the development and control of the behavior of nanocomposites – the assembly of materials on a nanometric level – using carbon nanotubes, which have unusual properties, such as very high hardness. "The goal is to find out whether the properties of these nanotubes will enable us to obtain more damage-resistant materials. At the moment, such nanocomposites don’t exist. Therefore, this is theoretical research: simulating the behavior of such nanomaterials, suggesting strategies to experimental scientists for creating these new materials. The work we are doing at the nanometric level could result in the development of materials that are resistant to very high temperatures, which would be interesting for the aerospace industry, the production of jet engines, or in designing the leading edges of wings in high-speed aircraft, where the heat is intense."
A new approach
Curtin did not leave his research group behind at Brown – they will join him at EPFL. The professor is also going to begin working in a new area of research, with the idea of combining computational modeling, applied mechanics, and mechanical concepts for influencing and controlling different chemical reactions relevant, for example, to the creation or conversion of fuels.
As Director of the Institute of Mechanical Engineering, he intends to encourage strongly interactions between laboratories, putting emphasis on problems associated with energy, i.e. generation, conversion, and management, where the Institute already has significant strengths. "I would like the faculty members to actively exchange new ideas, in the hope that new concepts can take shape," he notes. "EPFL is a very stimulating place, with the resources that enable researchers to pursue, and achieve, exciting and challenging goals, in science and engineering."