Figure 3. Characterization of microdroplets production with on-the-fly nozzle exchange.
(a) Coaxially flowing water in oil using nozzles with different inner diameters enabled the formation of droplets with diameters spanning more than an order of magnitude. (b) Switching between two stable droplet production size regimes by exchanging the nozzle was achieved within one minute. (c-e) Per nozzle, the droplet size was fine-tuned by tuning the flow rate and thereby the capillary number of the continuous phase. (f) All nozzles were compatible with the production of monodisperse (CV <5%) droplets. Scale bars indicate 350 μm.