Rupture of a Liquid Bridge between a Cone and a Plane

Abstract

In this work, a systematic experimental study of the rupture of an axially symmetric liquid bridge between a cone and a plane was performed, with focus on the volume distribution after break up. A model based on the Young-Laplace equation is presented and its solutions are compared to experimental data. Cones and conical cavities with different aperture angles were used in our experiments. We found that this aperture influences the potential pinning of the contact line, the meniscus shape and therefore the liquid transfer. For half aperture angles α < 70°, where no pinning was observed, the liquid bridge slips off from the cone and almost no transfer to the cone is observed. However, at α > 70°, contact line pinning on the cone induces a net liquid transfer to the cone at rupture. In the case of conical cavities, a maximum of liquid transfer is observed for at α =110°. The distance at which the rupture of the liquid bridge occurs is also discussed. The model can fairly predict the transfer ratio and the rupture height of the liquid bridge.

Rupture of Liquid Bridges on Porous Tips: Competing Mechanisms of Spontaneous Imbibition and Stretching

“…Notably, our estimation of 𝐿 𝑟 can keep consistent with the conclusion for solid tips (i.e., 𝑅 𝑇 = 0) reported in Ref 8 , whilst the proposed empirical equation can capture the additional contribution from the porous substrates. This study on rupture of liquid bridges suggests another potential way to accurately control liquid transfer and manipulate droplets required by microfluidics and microfabrication.…”

“…As suggested in reference 8 , with the contact line movement on the solid surface, the liquid bridge finally break up and part of liquid will be left on the tip, and the volume of the leftover is a function of tip geometry and surface property. However, for a porous tip, the imbibition inside the porous zone and outside stretching, as two competing factors, together impact the rupture of capillary bridges and liquid retention furtherly, as shown in Figures 3 and 4.…”

“…Many existing works mainly focuses on the simple geometries, i.e., plane to plane 26 , sphere to sphere [27][28] or sphere to plane [29][30] . A recent work by Tourtit et al 8 suggests that the surface geometry is another controlling condition for the quasi-static regime, and the relationship between the tip angle of a gripper and its liquid retention has been established. In many applications, substrates for liquid transfer are often porous.…”

Liquid Transfer for Viscoelastic Solutions

“…The truncated sphere method 17 is implemented to calculate the volume of the solution pools: V T,B = πh T,B 3R 2 0 + h 2 T,B /6. So, the transfer ratio, T r , is defined in the same way as previous authors 16,17,20,38,39 as: T r = V T /(V T + V B ), In the following, every T r data point and the associated error bar symbolise the average of five experiments and their dispersion, respectively,…”

Capillary Forces between Concave Gripper and Spherical Particle for Micro-Objects Gripping

“…The effects of the particle radius ratio, the contact angle, and the liquid bridge volume on the liquid transfer ratio were examined in detail. Furthermore, Tourtit et al [21] focused on the experimental study of the rupture of an axially symmetric liquid bridge between a cone and a plane. The capillary force applied on a tilted cylinder was measured using a customized atomic force microscope (AFM) probe to investigate the relationship between the capillary force and the dipping angle [22].…”