Title: Elastic waves in soft tissues

Speaker: Michel Destrade, Professor

School of Mathematics, Statistics and AppliedMathematics, NUI Galway, Ireland.

Venue:A322, An-Zhong Building

Time:10:00-11:30Nov. 28. (Tuesday)

Abstract:

Biological soft tissues and soft gels are difficult to study and model mathematically. Bioengineers often see tissues as engineering materials and try to evaluate their mechanical properties by relying on standard testing protocols, such as tensile testing, simple shear, torsion, etc. These processes take place in the laboratory, where a sample is cut out of a cadaver and placed into a testing machine. But the mechanical properties of living tissues are highly sensitive to their environment and the destructive testing protocols only give a rough indication of their order of magnitude.

To test soft tissues properly, non­destructively, and non­invasively, we can rely on the propagation of elastic waves. Just like a piano tuner can infer some information simply by tapping a cord while changing its state of stress, we can study the influence of pre­stress on the speed of elastic waves traveling in a soft solid. This idea forms the basis of the theory of acousto­elasticity, which can be dated back to early works of Brillouin, and has been used successfully in the past for hard elastic solids such as rocks and metals.

With this talk, we will explore the extension of acousto­elasticity to soft elastic solids, which can be subjected to large deformations in service. We will look at theoretical, numerical, experimental, and even clinical results, generated in particular on gels, brain, breast, and skin.

Short bio:

Michel Destrade is the Chair of Applied Mathematics at NUI Galway, and Adjunct Professor of Mechanical Engineering at University College Dublin, Ireland. Previously, he worked as a Marie Curie Fellow at University College Dublin; as a Visiting Assistant Professor at Texas A&M University; and as a Chargé de Recherche at the Institut D'Alembert, Université Pierre et Marie Curie.

His research interests are in nonlinear elasticity, in the stability of elastomers and biological soft tissues, and in linear, linearized, and non­linear waves. In those fields, he has co­ authored 3 invited book chapters and 110 publications in refereed international journals. He is currently Reviews Editor for Proceedings of the Royal Society A and Contributing Editor in Solid Mechanics for International Journal of Non­Linear Mechanics. His research has been supported by several competitive grants awarded, among others, by the European Commission; Royal Society; British Council; Agence Nationale pour la Recherche; CNRS; Science Foundation Ireland; Enterprise Ireland and the Irish Research Council.