Nonlinear physics, complex fluids, and biophysics

This axis joins 5 research groups around non-linear physics, complex fluids, and biophysics. Experimental, numerical, and theoretical approaches are all used to tackle problems in these areas.

Complex fluids

Description

Our centers of interest focus on the surface and interface dynamics in hydrodynamics, in soft matter and in crystal growth. Our studies are based upon both experimental and theoretical investigations. The understanding of the fundamental mechanisms governing interfacial dynamics corresponds to important stakes in the modelling of natural phenomenon as well as in industrial applications. Our activities mainly concern:

The propagation of nonlinear waves:
i) At the free surfaces of liquids: experimental evidences for new types of large amplitude solitary waves.
ii) In grain piles or in solid cellular materials, direct visualization of the sound waves propagation by means of the induced birefringency.
iii) In soap foams, by direct visualization or by X-ray microtomography of the flow in the liquid films or micro-channels.

Dynamics of capillary objects (jets, drops and films):
i) Local study of the drainage in soap films in various configurations: impact of a liquid jet or film rotation.
ii) Dynamics of droplets, jets and elastic solids.
iii) Leidenfrost effect of droplets submitted to thermal or magnetic forcing.
iv) Condensation phenomenon and dew recovering in dry countries: covering and process optimisation (use of super-hydrophobic or absorbent surfaces).
v) Rearrangement of the bubbles in a flowing foam; use of fast X-ray microtomography. 

Dynamics of growth patterns:
i) Modelling of quantum dots via hetero-epitaxy in semi-conductors.
ii) Morphogenesis in basalt columns.

Team members

Argentina Médéric
Célestini Franck
D'Angelo Christophe
Fraysse Nathalie
Fu Li
Giombini Guillaume
Karamaoun Cyril
Medici Marie-Gabrielle
Raufaste Christophe – group leader
Sanchez-Rodriguez Jesus
Yoshikawa Harunori

Magnetorheology and nanomaterials

Description

New materials with specific properties are designed by assembling nano- or microparticles that are functionalized to improve their dispersion in a suspending medium and to impart them specific properties required for different applications. For example, magnetic nano- and microparticles are dispersed in a liquid in order to form a magnetorheological fluid whose viscosity can be strongly increased by application of a magnetic field. We also develop new applications of magnetic particles such as their functionalization for pollutant or biomolecule capture on their surface. Control over nanoparticle aggregation and over nanoparticle architecture is also an important aspect of our research dealing with reinforcement of mechanical properties of several composites.

Team members

Alves Marins Jessica
Baran Sumeyra-Seniha
Bossis Georges
Ciffréo Alain
Hurel Charlotte
Godeau Guilhem
Gonzales Garrido Manuel
Julien Alan
Kuzhir Pavel – group leader
Li Xin
Meloussi Mounir
Lomenech-Humbert Claire
Queiros Campos Jordy
Raboisson-Michel Maxime

Microfluidics, physical-chemistry and biology at interfaces

Description

The MIMIC team develops research at the interface between physics, chemistry and biology. The team focuses on physical interfaces as well (drops, bubbles, surfaces, membranes). Our approach combines experiments (fast imaging, microscopies, microfluidics…), theory (fluid dynamics, theoretical chemistry, applied math) and of numerical simulations (finite differences, pseudospectral methods, molecular dynamics…). Our research is genuinely interdisciplinary and part of our work is conducted in close collaboration with biologists. Our interests range from: i) Fluids and microfluidics, wetting and drops, cavitation bubbles dynamics and biomimetics. ii) Biophysics of fast motion and collective motion in plants and fungi, bacterial biofilms and fungal growth, collective behavior of swimming zoospores, physics of olfaction, intracellular pH regulation. iii) Granular and particular materials.

Team members

Betti Lorenzo
Bouret Yann
Cohen Céline
Lechantre Amandine
Noblin Xavier – group leader
Thomen Philippe

Out of equilibrium and nonlinear physics

Description

Nonlinear physics is a discipline that takes its roots from the work of Henri Poincaré in the 19th century. It has been developed in the 1960s through the observation, the development of dynamical systems theory and numerical experimentation. It is a multidisciplinary science that has many fields of application. A common denominator in these fields is the use of concepts of instability, bifurcations, excitability, chaos and the emergence of complex dissipative structures. Our research team is currently developing the following research topics: Biophysics, Optical-non-linear, hydrodynamic and Crystal growth.

Team members

Frisch Thomas
Gil Lionel
Krinski Valentin
Nazarenko Sergey – group leader
Seminara Agnese
Sepulchre Jacques-Alexandre
Simonnet Eric
Tissoni Giovanna
Zhu Ying
Zolesio Jean-Paul

Concentrated suspensions rheology

Description

Creeping flows of non-Brownian suspensions are ubiquitous in Industry or in nature. Even when the suspending fluid is Newtonian, these suspensions exhibit a complex rheology especially when the solid fraction is large (shear-thinning, shear-thickening, normal stress differences, shear-induced migration…). We aim to identify and to understand the mechanisms involved at the particle scale that are responsible for these complex behaviours. To this purpose, we use cross-linked numerical and experimental approaches. We develop continuous flow computation based on Finite Volume Method as well as discrete simulations based on Force Coupling Method. Experimental studies are carried out using conventional or non conventional rheometry (suspension imaging, particle stress measurement). At last we are interested in applications (fresh concrete and propergol rheology, sediment transport).

Team members

Blanc Frédéric
Gilbert Duncan
Lemaire Elisabeth – group leader
Lobry Laurent
Orsi Michel
Peters François