Periodic Droplet Formation in Chemically Patterned Microchannels

Abstract

Simulations show that when a phase-separated binary AB fluid is driven to flow past chemically patterned substrates in a microchannel, the fluid exhibits unique morphological instabilities. For the pattern studied, these instabilities give rise to the simultaneous, periodic formation of monodisperse droplets of A-in-B and B-in-A. The system bifurcates between time-independent behavior and different types of regular, non-decaying oscillations in the structural characteristics. The surprisingly complex behavior is observed even in the absence of hydrodynamic interactions and arises from the interplay between the fluid flow and patterned substrate, which introduces non-linearity into the dynamical system.

References in corpus (3)

• Theory of Phase Ordering Kinetics
• Coarse-grained description of thermo-capillary flow
• Interface and contact line motion in a two phase fluid under shear flow

Cited by in corpus (6)

• Physics of Active Emulsions
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• Rayleigh and depinning instabilities of forced liquid ridges on heterogeneous substrates
• Capillary filling with wall corrugations] Capillary filling in microchannels with wall corrugations: A comparative study of the Concus-Finn criterion by continuum, kinetic and atomistic approaches
• Controlling drop size and polydispersity using chemically patterned surfaces
• Geometry-induced pulse instability in microdesigned catalysts: the effect of boundary curvature