Interaction of elastocapillary flows in parallel microchannels across a thin membrane

We report the interaction of counter elastocapillary flows in parallel microchannels across a thin membrane. At the crossing point, the interaction between the capillary flows via the thin membrane leads to significant retardation of capillary flow. The drop in velocity at the crossing point and velocity variation after the crossing point are predicted using the analytical model and measured from experiments. A non-dimensional parameter J, which is the ratio of the capillary force to the mechanical restoring force, governs the drop in velocity at the crossing point with the maximum drop of about 60% for J = 1. The meniscus velocity after the crossing point decreases (J < 0.5), remains constant (0.5 < J < 0.6), or increases (J > 0.6) depending on the value of J. The proposed technique can be applied for the manipulation of capillary flows in microchannels.