Rapid Patterning of PDMS Microfluidic Device Wettability Using Syringe-Vacuum-Induced Segmented Flow in Nonplanar Geometry.

We present a simple and rapid method to spatially pattern the surface wetting properties of PDMS microfluidic devices by layer-by-layer (LbL) deposition of polyelectrolytes using syringe-vacuum-induced segmented flow in nonplanar geometry. Our technique offers selective surface modification in microfluidic chips with multiple flow-focusing junctions, enabling production of monodisperse double- and triple-emulsion drops.