Related papers: How Spontaneous Electrowetting and Surface Charge …
We study the deformation of soft solid layers in the presence of sessile droplets or capillary bridges. By incorporating the surface tension balance at the contact line, we examine the rotation of the wetting ridge and the corresponding…
When a droplet gently lands on an atomically smooth substrate, it will most likely contact the underlying surface in about 0.1 s. However, theoretical estimation from fluid mechanics predicts a contact time of 10 to 100 s. What causes this…
The transport of small quantities of liquid on a solid surface is inhibited by the resistance to motion caused by the contact between the liquid and the solid. To overcome such resistance, motion can be externally driven through gradients…
We consider analytically and numerically head-on collision between two self-propelled drops. Each drop is driven by chemical reactions that produce or consume the concentration isotropically. The isotropic distribution of the concentration…
Gradient, chemically modified, flat surfaces enable directed transport of droplets. Calculation of apparent contact angles inherent for gradient surfaces is challenging even for atomically flat ones. Wetting of gradient, flat solid surfaces…
Liquid droplets usually wet smooth and homogeneous substrates isotropically. Recent research works have revealed that droplets sit, slide and spread anisotropically on uniaxially stretched soft substrates, showing an enhanced wettability…
The nature of adhesion of droplets to surfaces is a long pending scientific question. With the evolution of complex surfaces, quantification and prediction of these forces become intricate. Nevertheless, understanding these forces is highly…
Controlling the motion of non-Newtonian drops on surfaces is crucial for applications ranging from inkjet printing to biomedical devices and food processing. While the macroscopic behavior of viscoelastic drops sliding on tilted hydrophobic…
We report an experimental investigation of the spontaneous motion of liquid droplets on soft gels with a crosslinking gradient. By systematically adjusting the spatial difference in crosslinking density, we observed that millimeter-sized…
Although realizing wetting transitions of droplets spontaneously on solid rough surfaces is quite challenging, it is becoming a key research topic in many practical applications which require highly efficient removal of liquid. We report…
Fast contact-line motion of a droplet spreading on a solid substrate under the electrowetting effect generates strong capillary waves on the droplet's surface. The capillary waves may be strong enough to induce ejection of a satellite…
Superrepellency is a favorable non-wetting situation featured by a dramatically reduced solid/liquid contact region with extremely low adhesion. However, drop impact often brings out a notable extension of the contact region associated with…
Gas-phase microdroplets have recently demonstrated exceptional chemical properties via suspected mechanisms such as contact electrification and surface charge pinning, producing high surface electric fields. Here, microdroplets are injected…
Nanodroplets residing near wedges or edges of solid substrates exhibit a disjoining pressure induced dynamics. Our nanoscale hydrodynamic calculations reveal that non-volatile droplets are attracted or repelled from edges or wedges…
We derive a model for voltage-induced wetting, so-called electrowetting, from the principle of virtual displacement. Our model includes the possibility that charge is trapped in or on the wetted surface. Experimentally, we show reversible…
Water-in-oil emulsions and droplets exhibit completely different physico-chemical properties compared to oil-in-water emulsions and droplets. Thus, directly applying a standard theoretical model to water-in-oil systems cannot describe these…
When a liquid drop impacts on a heated substrate, it can remain deposited, or violently boil in contact, or lift off with or without ever touching the surface. The latter is known as the Leidenfrost effect. The duration and area of the…
The impact of a jet of droplets upon surfaces of varying hydrophobicity is studied via high-speed imaging. Microstructures on silicone surfaces consisting of cylindrical pillars of varying sizes and spacings are utilized to enhance…
In nature, high-speed rain drops often impact and spread on curved surfaces e.g. tree leaves. Although a drop impact on a surface is a traditional topic for industrial applications, drop-impact dynamics on curved surfaces in natural…
When micrometric drops coalesce in-plane on a superhydrophobic surface, a surprising out-of-plane jumping motion was observed. Such jumping motion triggered by drop coalescence was reproduced on a Leidenfrost surface. High-speed imaging…