Soft matter interfaces

Dans ce cours, nous introduirons les concepts clef de la matière dite "molle" (soft matter), vus sous l’angle de ses interfaces. La matière molle pourrait être définie comme l’ensemble des problématiques qui s’intéressent aux "formes complexes et à la structuration multiéchelle de la matière". Dans ce domaine il s’agit de comprendre et mettre au point des matériaux aux propriétés paradoxales ou ambiguës : ainsi le mélange de deux phases aussi fluides que l’eau et l’air peut-il produire le quasi-solide qu’est, à certains égards, une mousse à raser.

Soft Matter Physics

Soft Matter refers to diverse materials such as polymers, colloids, granular materials or liquid crystals, that display complex features, as showing fluid or solid like properties depending on the external solicitation, anisotropic mechanical properties or the appearance of yield stresses

Physics of multicellular systems

The development of animals, starting from a single cell to produce a fully formed organism, is a fascinating process. Its study is currently advancing at a rapid pace thanks to combined experimental and theoretical progress, yet many fundamental questions remain to be answered.

This course will address the fundamental theoretical concepts underlying the self-organization of multicellular systems, from gene regulation to the mechanics of active biological materials. The course will be based on various concepts from theoretical physics: dynamical systems, soft and active matter, the mechanics of continuous media, numerical modeling, etc.

Algorithms and computation

Computational physics plays a central role in all fields of physics, from classical statistical physics, soft matter problems, and hard-condensed matter. Our goal is to cover the basic concepts underlying computer simulations in classical and quantum problems, and connect these ideas to relevant and contemporary research topics in various fields of physics. In the TD’s you will also learn how to set, perform and analyse the results of simple computer simulations by yourself, covering a wide range of topics. We will use Python, but no previous knowledge of this programming language is needed.

Transfers in complex fluids

This course deals with transfers in complex fluids, which are ubiquitous processes in everyday life and industrial applications, as well as in geological or biological systems. Different types of transfers will be examined : first, drying and dissolution and, in a second part, wetting of a solid surface. The specificities of the drying of complex fluids will be highlighted, and associated phenomena such as glass transition, Marangoni effects, etc. will be described quantitatively in the light of recent literature. The mechanisms of the reverse process of dissolution will also be detailed. Then, starting from the description of the wetting of a solid by a simple liquid, we will see how introducing complexity in this multiphase problem (viscoelasticity, surface-volume exchanges, intermediate characteristic length scale, activity…) modifies the contact between media. The related challenges posed in industrial applications will also be detailed.

 
Active matter and collective behaviour

The lectures offer a statistical-physics perspective on active matter, which encompasses systems whose fundamental constituents dissipate energy to exert forces on the environment. This out-of-equilibrium microscopic drive endows active systems with properties unmatched in passive ones. From molecular motors to bacteria and animals, active agents are found at all scales in nature. Over the past twenty years, physicists and chemists have also engineered synthetic active systems in the lab, by motorizing particles whose sizes range from nanometers to centimeters, hence paving the way towards the engineering of active materials.

The lectures will rely on the modern tools of statistical mechanics, from stochastic calculus to field theoretical methods, using both theoretical models and experimental systems to illustrate the rich physics of active matter.