10.11.11 - Gérard Gremaud has been awarded the Zener medal. This distinction recognizes important contributions in the study of solid deformations.

Anelasticity… behind this strange term hides a simple physical concept: it’s the characteristic of an elastic object that, after having been stretched and then released, returns to its original form, but with a small time lag. The Zener medal is awarded in this field of study once every three years by the International Conference on Internal Friction and Ultrasonic Attenuation in Solids (ICIFUAS). Gérard Gremaud, a researcher in EPFL’s Complex Matter Physics Laboratory, now belongs to the short list of laureates. His original measurement technique based on sound waves, called mechanical spectroscopy, and his theoretical models have led to considerable progress in the field. Here’s an interview with this unusual physicist.

How did you come up with this new observation technique based on sound waves?

I’ve always liked to build things, but I’ve never really liked using what I’ve built or designed. I don’t really like to make measurements. What I really enjoy is understanding things. That’s what motivates me: curiosity. I am so curious about matter that I almost became a sculptor. In the case of mechanical spectroscopy, it’s about finding a way to probe a material in depth, to understand how it behaves at the small scale. To do this, we applied several kinds of acoustic vibrations. Low frequencies to create microscopic phenomena associated with deformations, and ultrasound, which, like sonograms, give us information on these mechanisms. The challenge is to bring several different sub-fields of physics together: acoustics, electronics, cryogenics, solid-state physics, etc.

What value does this medal have for you? Do you consider it an important achievement?

It has above all a personal value. It’s the culmination of the ideas and the approach that I contributed to the study of anelasticity. By studying the behavior of materials at the microscopic scale with my new technique, and by developing theoretical models for understanding the observations, it was possible to comprehend and confirm the mechanisms behind many internal friction phenomena that play an important role in the deformation of an object.

Isn’t it hard to combine interdisciplinary studies, teaching and research?

Keeping an open attitude is critical. Integrating various disciplines and points of view allows one to discover new, promising directions for research. Sharing this knowledge is just as important. I think that as long as you haven’t taught a subject, you cannot completely understand it. (NDLR: Gremaud does physics experiments once a month for the general public). I’m also continuing in this direction by writing a series of books that offer a new approach to the physics of deformable environments.


Author:Nicolas GuérinSource:Institute of Condensed Matter Physics