In applications like drug delivery, it’s often desirable to encapsulate one or more liquid droplets in an additional immiscible fluid. These drops-within-drops, called double emulsions, are typically a multi-step process, created from the innermost drop outward. In this new microfluidic technique, though, researchers are able to create multi-component emulsions in a single step. A double-bored capillary tube creates the two inner droplets (both water, dyed different colors) while oil flows down the outside of the injection tube to encapsulate the droplets. The multi-component double emulsions then flow as one to the right in the outer carrier fluid. The spacing of the capillary tubes is critical to prevent the inner droplets from coalescing with one another. (Video credit: L. L. A. Adams et al.)
Encapsulating Droplets
