Symmetric and asymmetric capillary bridges between a rough surface and a parallel surface

Area of Science:

• Physics
• Materials Science
• Surface Science

Background:

• Capillary bridges between surfaces are crucial in many scientific and industrial applications.
• Existing research primarily focuses on symmetric capillary bridges between smooth surfaces.
• Understanding asymmetric and rough surface capillary bridges remains a challenge.

Purpose of the Study:

• To extend analytical solutions for capillary bridge shapes to asymmetric and rough surfaces.
• To experimentally verify the extended analytical solution for various liquids and surface topographies.
• To develop a protocol for predicting capillary bridge profiles from volume and height.

Main Methods:

• Development of an instrument to form capillary bridges by squeezing liquid drops.
• Extension of an analytical solution using elliptical integrals to account for asymmetry and surface roughness.
• Experimental verification using water, Kaydol, and dodecane on smooth and rough surfaces.

Main Results:

• The extended analytical solution accurately describes both symmetric and asymmetric capillary bridges on smooth and rough surfaces.
• Experimental data showed good agreement with predicted profiles for small drops, where gravity effects are minimal.
• A reliable protocol for determining capillary bridge profiles from volume and height was established and validated.

Conclusions:

• The developed analytical solution provides a robust framework for understanding capillary bridge phenomena beyond idealized smooth surfaces.
• The findings have implications for controlling liquid behavior in complex interfaces, relevant to fields like printing and coating.
• The validated protocol offers a practical tool for researchers and engineers working with capillary phenomena.