title: Simulating the dynamic behavior of immiscible binary fluids in three-dimensional chemically patterned microchannels.
abstract: Using computer simulations, we investigate the behavior of an immiscible binary AB fluid that is driven to flow through a microchannel, which is decorated with a checkerboard pattern of chemically distinct A- and B-like patches on the top and bottom walls. We isolate conditions where the coupling between the imposed flow field and thermodynamic interactions yields a rich interfacial behavior between the A and B fluids and complex velocity patterns over the checkerboard domains. In effect, the A and B fluids undergo extensive mixing in specific regions of the channel, even for low Reynolds number flow. Decreasing the height-to-width ratio of the patterned microchannel enhances the extent of mixing between these two components. On the other hand, the length of the A/B interfaces is optimized in microchannels that have a square cross section. The results provide guidelines for designing microfluidic devices that can be used to effectively intermix multicomponent fluids.
authors.affiliation: Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
authors.forename: Olga
authors.initials: O
authors.lastname: Kuksenok
authors.forename: Anna C
authors.initials: AC
authors.lastname: Balazs