Synergetic effects of channel size and liquid properties on capillary-driven flow

Abstract

We conducted experiments to investigate the synergetic effects of the channel size and liquid properties on capillary-driven flow in open rectangular microchannels. Pure water, 20 wt% glycerol solution and 20 wt% ethanol solution were used as the working fluids in the Si superhydrophilic microchannels. We found that a larger ratio of surface tension to viscosity of the working fluid results in a greater imbibition rate. The optimal channel size was obtained when the aspect ratio of channel width to height was 2, in spite of the discrepancy in the working fluids. The experimental results were consistent with the theoretical model proposed in this work.