Capillary Forces between Two Spheres with a Fixed Volume Liquid Bridge:  Theory and Experiment

Langmuir ◽  
2005 ◽  
Vol 21 (24) ◽  
pp. 10992-10997 ◽  
Author(s):  
Yakov I. Rabinovich ◽  
Madhavan S. Esayanur ◽  
Brij M. Moudgil
Keyword(s):  
Liquid Bridge ◽  
Capillary Forces ◽  
Fixed Volume ◽  
Theory And Experiment

Electrohydrodynamic stability: Taylor–Melcher theory for a liquid bridge suspended in a dielectric gas

2002 ◽  
Vol 452 ◽  
pp. 163-187 ◽  
Author(s):  
C. L. BURCHAM ◽  
D. A. SAVILLE
Keyword(s):  
Surface Tension ◽  
Dielectric Constant ◽  
Electric Fields ◽  
Liquid Bridge ◽  
Numerical Solutions ◽  
Specific Conductivity ◽  
Axisymmetric Deformation ◽  
Aspect Ratios ◽  
The Stability ◽  
Theory And Experiment

A liquid bridge is a column of liquid, pinned at each end. Here we analyse the stability of a bridge pinned between planar electrodes held at different potentials and surrounded by a non-conducting, dielectric gas. In the absence of electric fields, surface tension destabilizes bridges with aspect ratios (length/diameter) greater than π. Here we describe how electrical forces counteract surface tension, using a linearized model. When the liquid is treated as an Ohmic conductor, the specific conductivity level is irrelevant and only the dielectric properties of the bridge and the surrounding gas are involved. Fourier series and a biharmonic, biorthogonal set of Papkovich–Fadle functions are used to formulate an eigenvalue problem. Numerical solutions disclose that the most unstable axisymmetric deformation is antisymmetric with respect to the bridge’s midplane. It is shown that whilst a bridge whose length exceeds its circumference may be unstable, a sufficiently strong axial field provides stability if the dielectric constant of the bridge exceeds that of the surrounding fluid. Conversely, a field destabilizes a bridge whose dielectric constant is lower than that of its surroundings, even when its aspect ratio is less than π. Bridge behaviour is sensitive to the presence of conduction along the surface and much higher fields are required for stability when surface transport is present. The theoretical results are compared with experimental work (Burcham & Saville 2000) that demonstrated how a field stabilizes an otherwise unstable configuration. According to the experiments, the bridge undergoes two asymmetric transitions (cylinder-to-amphora and pinch-off) as the field is reduced. Agreement between theory and experiment for the field strength at the pinch-off transition is excellent, but less so for the change from cylinder to amphora. Using surface conductivity as an adjustable parameter brings theory and experiment into agreement.

Capillary forces on wet particles with a liquid bridge transition from convex to concave

2020 ◽  
Vol 363 ◽  
pp. 59-73 ◽  
Author(s):  
Fei Xiao ◽  
Jiaqiang Jing ◽  
Shibo Kuang ◽  
Lu Yang ◽  
Aibing Yu
Keyword(s):  
Liquid Bridge ◽  
Capillary Forces ◽  
Wet Particles

Squeeze Effects in a Flat Liquid Bridge Between Parallel Solid Surfaces

2006 ◽  
Vol 128 (3) ◽  
pp. 575-584 ◽  
Author(s):  
Marie-Hélène Meurisse ◽  
Michel Querry
Keyword(s):  
Analytical Model ◽  
Liquid Bridge ◽  
External Load ◽  
Normal Force ◽  
Capillary Forces ◽  
Solid Surfaces ◽  
Capillary Suction ◽  
Capillary Effects ◽  
Liquid Lubricant ◽  
Normal Forces

When a liquid lubricant film fractionates into disjointed liquid bridges, or a unique liquid bridge forms between solid surfaces, capillary forces strongly influence the action of the fluid on the solid surfaces. This paper presents a theoretical analytical model to calculate the normal forces on the solid surfaces when squeezing a flat liquid bridge. The model takes into account hydrodynamic and capillary effects and the evolution of the geometry of the liquid bridge with time. It is shown that the global normal force reverses during the squeezing motion except in the case of perfect nonwetting; it is attractive at the beginning of the squeezing motion, and becomes repulsive at small gaps. When the external load is constant, capillary suction tends to accelerate the decrease in gap dramatically.

Effect of Contact Angle Hysteresis on Liquid Bridge while Sphere Particles are in Relative Movement

2013 ◽  
Vol 634-638 ◽  
pp. 2945-2948
Author(s):  
Song Yang ◽  
Jun Hua Wu ◽  
Xin Wang
Keyword(s):  
Contact Angle ◽  
Liquid Bridge ◽  
Capillary Force ◽  
Contact Angle Hysteresis ◽  
Capillary Forces ◽  
Hysteresis Effect ◽  
Liquid Volume ◽  
Liquid Bridges ◽  
Relative Movement ◽  
Important Impact

Hysteresis effect of contact angle has an important impact on liquid bridges between sphere particles. This effect is not limited to increasing liquid volume of fixed particles. The hysteresis effect of contact angle is expressed by fixed liquid volume while the two sphere particles are in relative movement. The hysteresis effect of contact angle on the liquid bridge is also significant. In this paper, the hysteresis effect of contact angle on capillary forces of liquid bridges is analyzed when the two sphere particles are in relative movement. Results indicate that contact angle hysteresis effects on capillary force are significant.

A Scheme of Micromanipulation using a Liquid Bridge

2003 ◽  
Vol 782 ◽  
Author(s):  
Kenichi J. Obata ◽  
Shigeki Saito ◽  
Kunio Takahashi
Keyword(s):  
Stability Analysis ◽  
Liquid Bridge ◽  
Capillary Force ◽  
Capillary Forces ◽  
Target Object ◽  
Liquid Volume ◽  
Target Point ◽  
The Stability

ABSTRACTThis paper presents a scheme of micromanipulation with a liquid bridge and an analysis of the capillary forces involved. The following procedure is considered in this article: (a) PICK UP: a probe, with liquid in the tip, approaches the target object. (b) A liquid bridge forms between the object and the tip of the probe. (c) The object is picked up by means of the capillary force of the liquid bridge. (d) TRANSPORT: The probe ascends, moves to the target point, and descends towards a substrate. (e) PLACEMENT: At a given height, a second liquid bridge made from a drop previously applied at the target point on the substrate, forms between the object and the substrate. (f) The probe ascends and the probe-object bridge collapses.The collapse can be predicted through the stability analysis of the bridge and its condition can be controlled by the regulation of the liquid volume. The liquid volumes required for the manipulation, in the first and second liquid bridge, are calculated in this paper.

CAPILLARY FORCES BETWEEN TWO PARALLEL PLATES CONNECTED BY A LIQUID BRIDGE

2015 ◽  
Vol 18 (3) ◽  
pp. 179-188 ◽  
Author(s):  
Morteza Dejam ◽  
Hassan Hassanzadeh ◽  
Zhangxing Chen
Keyword(s):  
Liquid Bridge ◽  
Capillary Forces ◽  
Parallel Plates

Analysis of the capillary forces between two small solid spheres binded by a convex liquid bridge

2010 ◽  
Vol 198 (2) ◽  
pp. 211-218 ◽  
Author(s):  
David Megias-Alguacil ◽  
Ludwig J. Gauckler
Keyword(s):  
Liquid Bridge ◽  
Capillary Forces ◽  
Solid Spheres

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

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 285
Author(s):  
Zenghua Fan ◽  
Zixiao Liu ◽  
Congcong Huang ◽  
Wei Zhang ◽  
Zhe Lv ◽  
...  
Keyword(s):  
Spherical Particle ◽  
Liquid Bridge ◽  
Capillary Force ◽  
Numerical Procedure ◽  
Capillary Forces ◽  
Radius Ratio ◽  
Solid Surfaces ◽  
Capillary Bridge ◽  
Half Filling ◽  
Significant Attention

The capillary action between two solid surfaces has drawn significant attention in micro-objects manipulation. The axisymmetric capillary bridges and capillary forces between a spherical concave gripper and a spherical particle are investigated in the present study. A numerical procedure based on a shooting method, which consists of double iterative loops, was employed to obtain the capillary bridge profile and bring the capillary force subject to a constant volume condition. Capillary bridge rupture was characterized using the parameters of the neck radius, pressure difference, half-filling angle, and capillary force. The effects of various parameters, such as the contact angle of the spherical concave gripper, the radius ratio, and the liquid bridge volume on the dimensionless capillary force, are discussed. The results show that the radius ratio has a significant influence on the dimensionless capillary force for the dimensionless liquid bridge volumes of 0.01, 0.05, and 0.1 when the radius ratio value is smaller than 10. The effectiveness of the theorical approach was verified using simulation model and experiments.

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