“…1,2 Notable advances in product control through droplet microreactors have been demonstrated for a wide range of synthesis applications, including the production of functional nanoparticles, 3,4 microcapsules 5,6 and biomaterials. 7,8 Generally, reactants are pre-dissolved in solvents injected into a confined microgeometry as dispersed phases divided into independent droplets via an immiscible carrier fluid, then reactions are triggered by the droplet fusion into uniform droplet microreactors that travel through the microchannel. 9,10 The majority of droplet-based microfluidic research on materials synthesis to date involves single-phase droplet microreactors, in which reagent streams are miscible.…”