Fig. 10. Microfluidic single emulsion transfer. a| Schematic of microfluidic droplet transfer assisted by a triangle post. The triangular post skimmed the oil flow and deflected the preformed W/O droplets along its hypotenuse into the extracellular aqueous phase (AQex). As droplets traverse the interface, a second lipid monolayer is coated and GUVs are formed (micrograph scale bar = 100 μm). Reproduced from ref. 151 with permission from the American Chemical Society, copyright [2011]. b| 2D schematic of microfluidic droplet transfer assisted by micro-step. The W/O droplets were transformed from the oil channel into a wider and deeper aqueous channel, where they picked up a second lipid monolayer from small vesicles in the Aqex. Reproduced from ref. 153 and 154 with permission from the Royal Society of Chemistry, copyright [2015 and 2016]. c| Schematic of microfluidic droplet transfer assisted by hydrodynamic traps (left). W/O droplets were generated by focusing flow, travelled through the delay line, and trapped by an array of cups. Schematic of layer-by-layer assembly (right (i)–(viii)) new phase boundaries were successively driven over the trapped droplets, and new lipid monolayers were deposited (micrograph scale bar = 100 μm). Reproduced from ref. 152 with permission from Springer Nature, copyright [2013]. d| Formation and analysis of droplet-stabilized GUVs. The copolymer-stabilized W/O droplets (dsGUVs) were separated at a T junction by a tributary oil flow containing 20 vol% destabilizing surfactants. The passive trapping structures drained the oil phase into adjacent outlets, and GUVs were released as the droplets entered the aqueous phase. Scale bars, 20 μm. Reproduced from ref. 155 with permission from Springer Nature, copyright [2017].
