Jamming, plasticity and material failure

The constituents of jammed and glassy soft materials are so densely packed and/or so tightly bound that their microscopic dynamics are orders of magnitude slower than in dilute systems.

Examples of such materials include, among others, concentrated colloidal suspensions or emulsions, polymer or particle gels, surfactant phases, foams. Our research focuses on the spontaneous (e.g. due to thermal energy) dynamics of these materials, as well as on their behavior in response to an external drive, e.g. a mechanical or thermal forcing.

Fractures propagating in a dense corn starch suspension. The suspension is confined between two parallel plates separated by a thin gap. The fracture is caused by the fast injection of solvent, at a point about 3 cm from the field of view. The field of view is about 1 cm2. The sample is illuminated using laser light : the temporal fluctuations of the resulting speckle patter carry information on the microscopic dynamics and the velocity field. By Frederic Lechenault, Serge Mora and Luca Cipelletti.

We leverage on our expertise in the formulation of well-defined supramolecular systems with original properties, combined with home-designed devices allowing a thorough characterization of the structure and dynamics of the system and a fine control of the imposed drive.