WG 4: Interfaces and Milli-Micro-Meter Fluid Mechanics
This work group focuses on phenomena at stake when fluids are manipulated at small scales, which is obviously commonly encountered in many industrial processes. The research interests comprise the physics of drops and jets, the properties of interfaces, which are free or stabilized by means of capillary adsorbed particles, various liquid encapsulation processes, as well as printing/coating using Newtonian as well as complex fluids.
The research group has been developing a strong expertise in both the experimental studies and the analytical modeling of drop formation and of drop evolution while subjected to impacts or collisions. A variety of configurations as already been studied in our group such as drop-drop collisions, drop-particle collisions, drop-jet collisions, drop impacts onto liquid films or onto pools. One of the main objectives is to predict the outcomes in terms of possible regimes such as fragmentation, coalescence, encapsulation or deposition. Driven by innovative applications, the group applies this basic knowledge to develop in air-microfluidics. A recent application is our patented method to continuously and regularly encapsulate micro-droplets into advanced fibers.
Further to classical liquid-liquid and liquid-gas interfaces, interfaces stabilized by capillary adsorbed particles are actively studied. Pioneer work is carried out on the properties of flat interfaces and drops coated by micro-particles - also called armored interfaces and liquid marbles, respectively. Of special interest are the mechanical responses of these interfaces when subjected to different forcing; and especially when strong strains and high shear rates are at stake, as these conditions often correspond to those of industrial processes.
Indeed, an important aspect of our work consists in applying our expertise developed via basic research to solve the challenges encountered in industrial applications. The latter comprise problems as diverse as the development of printing medicine, the coating of micro-textured surfaces, the efficient mixing of small quantities of complex fluids, the drying of isolated droplets or liquid films or the understanding of self-emulsification processes to enhance the bio-availability of poorly water soluble actives.