Experimental observation of capillary instabilities of two phase flow in a microfluidic T-junction

Abstract

This paper discusses the experimental observation of capillary instabilities of two-phase flow in a microfluidc T-junction. These instabilities are analogous to the classical Plateau-Rayleigh instabilities. The experiments were carried out with mineral oil and water in a rectangular microchannel of 100 μm width and depth of 75 μm. The interfacial tension of the system was around 3 mN/m after addition of a surfactant in the oil phase. We report on the instabilities observed in three fluid inlet configurations in T-junctions under the same flow parameters. The inlet geometry was found to have limited influence on the behaviour of the flow while the flowrate of the water phase is considered more important