research
Summary of the Project:

The applications of micro- and nanofluidics are now numerous, including lab-on-chip systems based upon micro-manipulation of discrete droplets, microcapillary devices fabricating emulsions of interest in food and medical industries (drug delivery), analytical separation techniques of biomolecules, such as proteins and DNA, and facile handling of mass-limited samples. The problems involved contain diverse nano and microstructures with a variety of lifetimes, touching atomistic scales (contact lines, thin films), mesoscopic collective behaviour (emulsions, glassy, soft-jammed systems) and hydrodynamical spatiotemporal evolutions (droplets and interface dynamics) with complex rheology and strong non-equilibrium properties. The interplay of the dynamics at the different scales involved still remains to be fully understood. Also, many new and “unexpected” phenomena have been observed experimentally which still deserve a complete understanding needed to foster new applications.

The fundamental research I address in this project aims to set up the unified framework for the characterization and modelling of interfaces in confined geometries by means of an innovative micro- and nanofluidic platform. The expected outcome is to control the stability of micro- and nanodroplets, investigate complex flow properties of model and real emulsions, from mesoscales down to their nanometer behaviour connected to contact-line dynamics, emerging slip length and molecular-hydrodynamical couplings. The main challenging and ambitious questions I intend to address in my project are: How the stability of micro- and nanodroplets is affected by thermal gradients? Or by boundary corrugation and modulated wettability? Or by complex rheological properties of the dispersed and/or continuous phases? How these effects can be tuned to design new optimal devices for emulsions production? What are the rheological properties of these new soft materials? How confinement in small structures changes the bulk emulsion properties? What is the molecular-hydrodynamical mechanism at the origin of contact line slippage? How to realistically model the fluid-particle interactions on the molecular scale?

The strength of the project lies in an innovative and state-of-the-art numerical approach, based on mesoscopic Lattice Boltzmann Models, coupled to microscopic molecular physics, supported by theoretical modelling, lubrication theory and experimental validation. Lattice Boltzmann is a well-established method to deal with complex flows in complex geometries. Here I intend to push it beyond the state-of-the-art to achieve a realistic description of the above high-risk and high-gain problems at the frontier of nowadays technological and fundamental research. Beside the novel and outstanding scientific problems I intend to address and solve, a long-term goal of the project is also to start, develop and consolidate a group, in the Rome environment, focused on fundamental and applied problems on complex fluids.