Séminaire 22.01.2018 – 14h00

Publié le : 22/01/2018

Sophie Marbach (Laboratoire de Physique Statistique, ENS) présentera le lundi 22 janvier 2018 à 14h, dans la salle Levisalles (T42-43, 1er sous-sol, salle 04), un séminaire intitulé :

Non-equilibrium separation : from biomimetic kidney-on-a-chip to active sieving


Filtering specific molecules is a challenge faced for several vital needs : from biomedical applications like dialysis to the intensive production of clean water. The domain has been boosted over the last decades by the possibilities offered by nanoscale materials. Filtration is however always designed according to a sieving perspective : a membrane with small and properly decorated pores allows for the selection of the targeted molecules. This inevitably impedes the flux and transport, making separation processes costly in terms of energy.

Here we investigate several radically innovative approaches to separation and filtration. We draw inspiration from biological systems (human kidney, aquaporins) and rationalize some new concepts for sieving, based on simple models. All these principles could be readily mimicked using existing technologies to build artificial dialysis devices or alternatives for advanced water recycling.

Teaser figures : (left) Principles of the central unit of the human kidney : salt is pumped on the right side to the central réservoir, increasing osmotic pressure, and driving water out. As a result only urea is left in the U-shaped tube. (right) Active sieving can be thought of in terms of a door that is mechanically opened and closed by some “crazy” Maxwell Demon and impacts the transport of particles through the door according to their dynamical properties. Active sieving can also be thought of in the longitudinal direction, for instance in puffy vibrating nanotubes.