Monday, January 9, 2012




(a) Schematic of a microfluidic double emulsion-maker unit, not to scale. Insets: top view and side view schematics showing angled junctions and height step. (b) Micrograph of a unit producing double emulsion drops; the scale bar denotes 100 μm. (c) Schematic of a parallelized double emulsion chip, comprising rows of microfluidic double emulsifier units that are connected through vertical through-holes to a layer of much larger distribution/collection channels, with each integrated row connected to another layer of yet larger distribution/collection channels. Channels marked light blue carry the core fluid, red the shell fluid, dark blue the continuous phase fluid, and gray the double emulsion product. (d) Photograph of an integrated chip; the coin (a US penny) is 19 mm across.

Double emulsions are useful templates for microcapsules and complex particles, but no method yet exists for making double emulsions with both high uniformity and high throughput. We present a parallel numbering-up design for microfluidic double emulsion devices, which combines the excellent control of microfluidics with throughput suitable for mass production. We demonstrate the design with devices incorporating up to 15 dropmaker units in a two-dimensional or three-dimensional array, producing single-core double emulsion drops at rates over 1 kg day−1 and with diameter variation less than 6%. This design provides a route to integrating hundreds of dropmakers or more in a single chip, facilitating industrial-scale production rates of many tons per year.

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