Effect of surface topology on contact line motion in open microchannels – A numerical study

The passive transport of liquid through micro-channels is the basis for building many microfluidic devices for biomedical applications. Surface topology of the micro-channel influences the motion of liquid-gas interface and the sudden change in cross-sectional area may result in pinning the macroscopic contact line. In this study, we presented detailed numerical simulations of liquid transport in micro-channels to study the effect of surface topology. Numerical results indicate that the topology change influences the liquid transport and pinning according to its macroscopic geometry, while other effects such as gravity inclination have no effect on liquid transport.