Fig. 6.
Interfacial analysis of air bubbles in microfluidic system. (a) 3-D schematic and (b) 2-D schematic of an air bubble spanning the entire cross-section of a liquid-perfused microchannel. The receding (θrec) and advancing (θadv) contact angles at the front and back of air bubble meniscus, respectively. (c) The air bubbles in a microchannel have the same pressure resistance regardless of their length/volume. Schematics showing air bubbles being removed by (d) conventional hydrophobic venting membrane and (e) wettability-contrast enabled microfluidic interconnect.