High-throughput production of satellite-free droplets through a parallelized microfluidic deterministic lateral displacement device

We present a parallel numbering-up device for microfluidic production of satellite droplet-free emulsions. The device consists of two stacked layers made of polydimethylsiloxane (PDMS). The bottom layer combines eight parallel sets of a microfluidic droplet generator (MFDG) and deterministic lateral displacement (DLD) array for size-based separation of main and satellite droplets. The top layer has input reservoirs to supply both the disperse and continuous phases evenly to the eight channels of the bottom layer. We employed 3D flow simulations to find the reservoirs most suitable for equal inflow distribution. Water-in-oil (W/O) droplets comprised of main droplets (∼67 μm in diameter) and satellite droplets (1–20 μm) were generated in the parallelized MFDGs, and they were then completely separated through the DLD arrays having a critical diameter of D_c = 37.1 μm. Thus, we confirmed production of satellite droplet-free emulsion droplets at 0.2 ml/h, eight times the processing throughput of single device (= 0.025 ml/h) without decrease in performance.