Two stories on Ostwald ripnening in microfluidic devices

I will first discuss the mechanical resistance of an armoured bubble, as a microscopic model of a pickering emulsion. In particular I will show measurements that contradict the classical elastic models of particle shells. Instead we find scalings that show that the shell behaves in a plastic way, which has important implications on the stability of Pickering emulsions. Next I will discuss the transition of how a highly monodisperse population of bubbles reaches the self-similar regime of ripening foams. The transition is found to take place through two successive dynamical regimes; the first corresponds to the nucleation and growth of disordered regions, followed by a second period that sees the increase in the polydispersity within these regions.

** References **

-- Taccoen, N., Lequeux, F., Gunes, D. Z. & Baroud, C. N. Probing the Mechanical Strength of an Armored Bubble and Its Implication to Particle-Stabilized Foams. Phys. Rev. X 6, 11010 (2016).

-- Dangla, R., Kayi, S. C. & Baroud, C. N. Droplet microfluidics driven by gradients of confinement. Proc. Natl. Acad. Sci. 110, 853–858 (2013).


Bio: Charles Baroud was trained as a physicist and engineer at MIT, then received a PhD at the University of Texas at Austin. Since then he has founded and now leads the microfluidics group at Ecole Polytechnique in Paris. The group has performed fundamental fluid dynamics research on multiphase flows in complex geometries, as well as developing a variety of technological approaches for droplet microfluidics. This has led to a scientific production of over 50 articles and 8 patents. In 2012 Charles Baroud received an ERC starting grant to develop applications of the microfluidic technologies for cell biology. This transition has now been completed with projects now exploring the drug resistane of bacteria, the 3D culture of mammalian cells, or the exploration of single-cell behavior. He is also co-founder and scientific advisor to Stilla Technologies, a spinoff from the Polytechnique lab that now commercialises a digital-PCR platform.