Interfacial tension based on-chip extraction of microparticles confined in microfluidic Stokes flows

摘要: Microfluidics involving two immiscible fluids (oil and water) has been increasingly used to produce hydrogel microparticles with wide applications. However, it is difficult extract the out of microfluidic Stokes flows oil that have a Reynolds number (the ratio inertia viscous force) much less than one, where dominant force tends drive move together surrounding oil. Here, we present passive method for extracting in flow from into aqueous solution on-chip by utilizing intrinsic interfacial tension between microparticles. We further reveal thickness an “extended confining layer” next interface must be smaller radius effective extraction. This uses simple planar merging microchannel design can readily fabricated integrated fluidic system