Meniscus arrest during capillary rise in asymmetric microfluidic pore junctions

Area of Science:

• Physics
• Fluid Dynamics
• Materials Science

Background:

• Capillary rise in porous media is crucial for understanding fluid transport.
• Asymmetric channel geometries can lead to complex fluid behaviors like meniscus arrest.
• Elongated pores in materials influence imbibition front dynamics.

Purpose of the Study:

• To experimentally investigate meniscus arrest events in asymmetric Y-shaped microfluidic junctions.
• To quantify the duration of these arrest events.
• To compare experimental findings with theoretical predictions for fluid dynamics in porous materials.

Main Methods:

• Utilized a microfluidic setup to create controlled Y-shaped channel junctions.
• Experimentally induced and observed capillary rise and subsequent meniscus arrest.
• Systematically varied channel width ratios, liquid viscosities, and feeding channel lengths.
• Measured the duration of meniscus arrest events.

Main Results:

• Confirmed the occurrence of long-lasting meniscus arrest events in the wider branch of asymmetric Y-junctions.
• Demonstrated that the arrest duration is directly proportional to the time taken for the meniscus to reach the junction.
• Achieved excellent quantitative agreement between experimental measurements and theoretical predictions across varied experimental conditions.

Conclusions:

• Meniscus arrest in asymmetric channel junctions is a significant phenomenon affecting imbibition fronts.
• The duration of meniscus arrest is predictable and quantitatively aligns with theoretical models.
• Findings have implications for modeling fluid transport in porous materials with complex pore structures.