During my PhD, I am interested in the dynamics of liquids near solid surfaces. I use molecular dynamics to probe the friction Lennard-Jones fluids on a model wall as the liquid becomes supercooled. I also study the slip and friction of polymer solutions on ideal substrate combining rheology, photobleaching techniques and neutron reflectivity. In particular, I am focusing on the dynamics of polymer chains near the wall as the chains are cooled down near their glass transition temperature.


  • Polymer physics
  • Rheology
  • Molecular Dynamics
  • Neutron reflectivity
  • Interfaces


  • Master ICFP in Soft Matter, 2019, Ecole Normale Supérieure de Paris
  • Bachelor in fundamental physics, 2017, Ecole Normale Supérieure de Paris
  • Classe préparatoire PCSI-PC*, 2013-2016, Lycée Joffre, Montpellier

Material Science – TD L3

Sept 2022 – Jan 2023

Science of measurement – TP IUT 2nd year

IUT Jan 2021 – Jun 2022

Introduction to Python language – TD/TP L1

Paris Diderot University Sept 2020 – Dec 2020

Quantifying liquid/solid friction with a rheometer

Using a novel approach, we quantify the friction between a viscous polymer solution and a smooth surface. In particular, we look at the shear-rate and temperature dependences of the friction coefficient.

Slip of polymer solutions: effect of temperature

Using a home-made velocimetry technique, we quantify the friction between polymer solutions and solid surfaces as a function of temperature. Coupling our measurements with bulk rheology, we can extract a lot of information about local friction between polymer chains and the wall.

Friction of a Kob-Andersen fluid

We use Molecular Dynamics simulations to study the role of temperature on the friction at the liquid/solid interface with a model system. In particular, we show that at high temperatures, both the viscosity and friction are well-described by activated processes while in the supercooled regime, there is a strong deviation from the usual Arrhenian law, leading to giant slip lengths.

See https://doi-org/10.1103/PhysRevE.107.025101 for more information.

Depletion and adsorption in polymer solutions probed by neutron reflectivity

We use neutron reflectivity to probe the interface between polymer solutions and solid substrates. We observe and quantify a depletion of polymer near the solid substrate. Interestingly, we show that depletion does not prevent adsorption of polymer chains on the wall.

See for more information.

Adsorption kinetics of PDMS melts

We study the temperature effect on the adsorption kinetics of polymer melts on silicon wafers. We show that PDMS melts adsorb in a peculiar way compared to other polymer melts, and this is likely to be due to its strong interaction with the silicon surface.

  • Simultaneous depletion and adsorption in polymer solutions near a solid wall“, S. Lafon, T. Outerelo-Corvo, M. Grzelka, A. Hélary, P. Gutfreund, L. Léger, A. Chennevière, F. Restagno, submitted, 2023,
  • Giant slip length at a supercooled liquid-solid interface“, S. Lafon, A. Chennevière, F. Restagno, S. Merabia, L. Joly, Phys. Rev. E, 2023, 107, 025101, https://doi-org/10.1103/PhysRevE.107.025101 (arxiv version:
  • Confinement effect on poly(ionic liquid) interfacial structure“, T. Outerelo-Corvo, S. Lafon, A. Hemmerle, E. Drockenmuller, F. Restagno, A. Chennevière, in preparation, 2023
  • Flow driven control of pulse width in excitable media“, A. Misselwitz, S. Lafon, J.-D. Julien, K. Alim, Phys. Rev. E., 2023, 107, 054218, (arxiv version:
  • Interaction between proteins and cellulose in a liquid crystalline media: Design of a droplet based experimental platform“, H. Voisin, E. Bonnin, M. Marquis, C. Alvarado, S. Lafon, T. Lopez-Leon, F. Jamme, I. Capron, International Journal of Biological Macromolecules, 2023, 245, 125488,
  • Reversible photocontrol of DNA coacervation“, S. Lafon, N. Martin, Methods in Enzymology, 2021, 646, 329-351,
  • The dual role of viscosity in capillary rise“, J. Delannoy, S. Lafon, Y. Koga, E. Reyssat, D. Quéré, Soft Matter, 2019, 15, 2757-2761,


You can find a curriculum below.


PhD Student

Paris-Saclay University

Oct 2020 – Present Orsay, France. As a PhD, I joined both the group Soft matter at interfaces in Laboratoire de Physique des Solides in Orsay and the group Biophysics and Soft Matter in Laboratoire Léon Brillouin in the CEA Saclay.        


Ecole Normale Supérieure d’Ulm

Sep 2016– Aug 2020 Paris, France. I’ve been studying fundamental physics and chemistry for four years at the Ecole Normale Supérieure d’Ulm. During this time, I’ve done five interships in academia in Paris, Bordeaux and Göttingen.