Multiscale Dynamics of Bubbles and Droplets in Microfluidic Networks

Abstract

Understanding the flow of confined bubbles and droplets within natural or man-made microchannel networks is crucial to a broad range of technologies ranging from enhanced oil recovery to microfluidic chip-based chemical analysis, synthesis and discovery. The traffic of droplet or bubble ensembles through even elementary microchannel networks is complex and nonlinear ? this makes it challenging to both design and engineer new networks and to predict the dynamical behavior of a known network. This thesis broadly aims to advance the current understanding of such phenomena by conducting rigorous and detailed experiments in simple yet prototypical microchannel topologies. Specifically, this thesis studies bubble/droplet-scale hydrodynamics, in terms of the pressure drop across confined bubbles and droplets translating through microchannels of rectangular cross-section, and how such local phenomena dictate the global behavior of trains of monodisperse bubbles or droplets as they flow through prototypical network components such as junctions.