One-step microfluidic approach for controllable production of gas-in-water-in-oil (G/W/O) double emulsions and hollow hydrogel microspheres

Here we introduce a one-step microfluidic device for the controllable generation of gas/water/oil (G/W/O) double emulsions. The structure of the double emulsions can be tuned easily by the three phase flow rates and the dimensional range of the encapsulated microbubbles can be expanded by integrating CO2 adsorption. The G/W/O double emulsions were successfully in situ photo-polymerized to fabricate hollow hydrogel microspheres with tunable structures.