Related papers: Why is surface tension a force parallel to the int…
A type of super-hydrophobic surface consists of a solid plane boundary with an array of grooves which, due to the effect of surface tension, prevent a complete wetting of the wall. The effect is greatest when the grooves are aligned with…
Microfluidic devices offer unique opportunities to directly observe multiphase flow in porous media. However, as a direct representation of flow in geological pore networks, conventional microfluidics face several challenges. One is that…
We investigate the dynamics of micron-scale drops pushed across a hydrophobic or superhydrophobic surface. The velocity profile across the drop varies from quadratic to linear with increasing height, indicating a crossover from a sliding to…
We present a fluid dynamics video showing how capillary rafts sink. Small objects trapped at an interface are very common in Nature (insects walking on water, ant rafts, bubbles or pollen at the water-air interface, membranes...) and are…
We consider the behaviour of a dielectric fluid-fluid interface in the presence of a strong electric field from a point charge and line charge, respectively, both statically and, in the latter case, dynamically. The fluid surface is…
In recent years, there has been a considerable interest in the mechanics of soft objects meeting fluid interfaces (elasto-capillary interactions). In this work we experimentally examine the case of a fluid resting on a thin film of rigid…
We study both diffuse and sharp liquid-vapor interfaces. The equilibrium equation of fluids is derived by using the principle of virtual work in a domain including the interfaces. For diffuse interfaces, the surface tension coefficient…
A comprehensive review of current analytical models, experimental techniques, and influencing factors is carried out to highlight the current challenges in this area. The study of fluid-solid boundary conditions has been ongoing for more…
Particles embedded in a fluctuating interface experience forces and torques mediated by the deformations and by the thermal fluctuations of the medium. Considering a system of two cylinders bound to a fluid membrane we show that the…
Deformation of a fluid interface caused by the presence of objects at the interface can lead to large lateral forces between the objects. We explore these fluid-mediated attractive force between partially submerged vertical cylinders.…
Tangential interactions between particles play a central role in suspension rheology. We show theoretically that these interactions, often attributed to contact friction, are a direct consequence of fluid flows between rough particles in…
Experiments over the last 50 years have suggested a tentative correlation between the surface (shear) viscosity and the stability of a foam or emulsion. We examine this link theoretically using small-amplitude capillary waves in the…
A concentration gradient along a fluid-fluid interface can cause flow. On a microscopic level, this so-called Marangoni effect can be viewed as being caused by a gradient in the pressures acting on the fluid elements, or as the…
When a water jet impinges upon a solid surface it produces a so called hydraulic jump that everyone can observe in the sink of its kitchen. It is characterized by a thin liquid sheet bounded by a circular rise of the surface due to…
Surface charge controls many static and dynamic properties of soft matter and micro/nanofluidic systems, but its unambiguous measurement forms a challenge. Standard characterization methods typically probe an effective surface charge, which…
The inhomogeneity of the plasma pressure near a conducting electrode is a cause for introducing the surface tension associated with the plasma-electrode interface. We evaluate the dependence of the surface tension on the density of the…
The effective capillary interaction potentials for small colloidal particles trapped at the surface of liquid droplets are calculated analytically. Pair potentials between capillary monopoles and dipoles, corresponding to particles floating…
Starch solutions, which are strongly non-Newtonian, show a surface instability, when subjected to a load. A droplet of the fluid is sandwiched between two glass plates and a weight varying from 1 to 5 kgs. is placed on the top plate. The…
An evaporating droplet is a dynamic system in which flow is spontaneously generated to minimize the surface energy, dragging particles to the borders and ultimately resulting in the so-called "coffee-stain effect". The situation becomes…
Hydraulic jumps in thin films are traditionally explained through gravity-driven shallow-water theory, with surface tension assumed to play only a secondary role via Laplace pressure. Recent experiments, however, suggest that surface…