Fig. 6: Droplet generation with two independently controlled dispersed phases.
From: Phase synchronization of fluid-fluid interfaces as hydrodynamically coupled oscillators
a Schematic diagram showing the two dispersed phases controlled independently in opposing branches of the double T junction. b–e In-phase synchronization of droplet generation through the independently controlled branches while the pressure applied to branch 1 (P1) is fixed, and only P2 is varied. Representative microscope images (P0 = 341 mbar and P1 = 301 mbar) are shown when (b) P1 = P2 with α = 0.98, and (c) when P1 ≠ P2 (bottom), which maintained the in-phase synchronization state with α = 0.93 despite the considerable difference in the sizes of droplets. d The difference in the volume of droplets from two branches (V1 from branch 1 and V2 from branch 2) and e the synchronization parameter α, is shown in relation to the difference between P1 and P2. For (d, e), each data points represent the average values of α and \(b_{{\mathrm{max}}}^ \ast\) measured from time-series data of the minimum 200 droplets; the error bars indicate standard deviations. f–h An example of droplet generation with different viscosities (Qo = 500 μL h−1, and Qw,1 = Qw,2 = 20 μL h−1). After three droplets are generated in the (f) out-of-phase mode, (g) two droplets are produced in the in-phase synchronization mode. h This 3:2 ratio of droplet generation from two branches is shown with the evolution of normalized volumes of each dispersed phase as a function of time. Blue arrows indicate the moment when the droplet breakups from the two interfaces coincide.
