Rupture of liquid bridges on porous tips: Competing mechanisms of spontaneous imbibition and stretching

TL;DR

This paper investigates how capillary effects influence liquid transfer during rupture of liquid bridges on porous tips, proposing a theoretical model to predict liquid retention considering geometry, porosity, and wettability.

Contribution

It introduces a novel time scale ratio R_T to compare spontaneous imbibition and external drag, advancing understanding of liquid transfer mechanisms on porous tips.

Findings

Theoretical model estimates liquid retention ratio based on tip properties.

Capillary effects significantly influence liquid transfer during rupture.

The approach aids in precise control of microfluidic liquid transfer.

Abstract

Liquid bridges are commonly encountered in nature and the liquid transfer induced by their rupture are widely used in various industrial applications. In this work, with the focus on the porous tip, we studied the impacts of capillary effects on the liquid transfer induced by the rupture through numerical simulations. To depict the capillary effects of a porous tip, a time scale ratio, R_T, is proposed to compare the competing mechanisms of spontaneous imbibitiona and external drag. In terms of R_T, we then develop a theoretical model for estimating the liquid retention ratio considering the geometry, porosity and wettability of tips. The mecahnism presented in this work provides a possible approach to control the liquid transfer with better accuracy in microfluidics or microfabrications.