Massive generation of tailored double emulsions

Uniform double-emulsion drops provide versatility in the membrane properties and microcapsule functions, which have advanced many natural sciences. However, the low throughput to the current microfluidics hinders their widespread use in further applications. Herein, we present a piezoelectric flow focusing (PFF) platform for rapid production of uniform double emulsions with tailorable sizes and morphologies. In this platform, the outer phase of the dispersed jet was subjected to a programmable piezoelectric signal and vibrated synchronously. Subsequently, the perturbation with specific frequency propagated along the jet surface and dominated the breakup processes. Finally, emulsion droplets with controllable size and morphology were then well achieved in controllable jetting regime with high throughput. More attractively, the platform enables preparing elaborate designs of more complex emulsions by easily modifying the channel topologies. We believe that this PFF platform opens an avenue for high-throughput generation of complex emulsions with controllable structures, and would be highly applicable in material science, energy applications, and environmental areas.