Scaled-up droplet generation in parallelised 3D flow focusing junctions

Monodispersed organic phase droplets with an average diameter from 20 to 200 µm were produced at the rate of up 20,000 per second in a glass microfluidic chip composed 7 parallel 3D flow focusing junctions 100 µm-deep channels. The continuous was 2 wt% polyvinyl alcohol solution, while dispersed dichloromethane, n-dodecane, and polydimethylsiloxane 10 cSt fluid corresponding dispersed-to-continuous-phase viscosity ratio 0.2, 0.8 6.1, respectively. Four different droplet generation regimes observed, dripping, squeezing, jetting, threading. regions where each these stable mapped using Weber number capillary phase. transitions between formation governed by phase, indicating that inertial forces more relevant than viscous controlling transition. Stable dripping regime junction maintained for least 6 h. coefficient variation sizes individual all combined < 3% under optimal conditions. size variations greater those within junction. Liquid plugs squeezing dispersed-to-continuous one. This study is first investigation multiple flow-focusing potential applications production drug microcarriers emulsification solvent evaporation, especially encapsulation controlled delivery lipophilic drugs. • CV could be formed junctions. over h regime. Plugs high rates. Dimensionless increased linearly ratio. Higher throughput achieved less