title: Simple, robust storage of drops and fluids in a microfluidic device.
abstract: We describe a single microfluidic device and two methods for the passive storage of aqueous drops in a continuous stream of oil without any external control but hydrodynamic flow. Advantages of this device are that it is simple to manufacture, robust under operation, and drops never come into contact with each other, making it unnecessary to stabilize drops against coalescence. In one method the device can be used to store drops that are created upstream from the storage zone. In the second method the same device can be used to simultaneously create and store drops from a single large continuous fluid stream without resorting to the usual flow focusing or T-junction drop generation processes. Additionally, this device stores all the fluid introduced, including the first amount, with zero waste. Transport of drops in this device depends, however, on whether or not the aqueous drops wet the device walls. Analysis of drop transport in these two cases is presented. Finally, a method for extraction of the drops from the device is also presented, which works best when drops do not wet the walls of the chip.
authors.affiliation: Complex Fluids Group, Martin Fisher School of Physics, Brandeis University, Waltham, MA 02454, USA.
authors.forename: Hakim
authors.initials: H
authors.lastname: Boukellal
authors.forename: Seila
authors.initials: S
authors.lastname: Selimović
authors.forename: Yanwei
authors.initials: Y
authors.lastname: Jia
authors.forename: Galder
authors.initials: G
authors.lastname: Cristobal
authors.forename: Seth
authors.initials: S
authors.lastname: Fraden
mesh_terms: D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D009821:Oils / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D009821:Oils; D014867:Water