Related papers: The microfluidic Kelvin water dropper
The Kelvin Water Dropper was discovered by Lord Kelvin in 1867 and it works on the principle of electrostatic induction. A working model of Kelvin Water Dropper is fabricated in the workshop facility of Physical Research Laboratory,…
Recently, our group reported that an any aqueous droplet dispensed from a pipette tip has considerable amount of electrical charge. This natural electrical charge of a droplet could cause undesired, unfamiliar experimental results. Since…
Charged water drops are more widespread than commonly acknowledged. For example, raindrops typically carry charges of order Q ~ 1 pC, while routine pipetting in the laboratory produces drops with Q ~ 50 pC. Here, we show that such modest…
Surface charging is a ubiquitous phenomenon with important consequences. On one hand, surface charging underpins emerging technologies such as triboelectric nanogenerators; on the other, uncontrolled charging can damage delicate…
Fluid triboelectrification, also known as flow electrification, remains an under-explored yet ubiquitous phenomenon with potential applications from material science to planetary evolution. Building upon previous efforts to position water…
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…
We present a microfluidic platform for two-dimensional manipulation of water droplets immersed in bulk oil-based ferrofluid. Although non-magnetic, the droplets are exclusively controlled by magnetic fields, without any pressure-driven…
This paper considers the interaction between two droplets placed on a substrate in immediate vicinity. We show here that when the two droplets are of different fluids and especially when one of the droplet is highly volatile, a wealth of…
A vertical connection of water is formed when a high voltage electrode is dipped in and pulled out of a container of deionized water. We considered the formation and dynamical characteristics of this vertical water bridge. For the first…
The process of drop formation from a nozzle can be seen in many natural systems and engineering applications. Here, we investigate the formation of a liquid droplet from a wettable nozzle. The behavior of a drop is complicated due to an…
We report an easy-to-implement method that allows the direct generation of water-in-water (w/w) single emulsions. The method relies on direct perturbation of the pressure that drives the flow of the dispersed phase of the emulsions. The…
It is well-known that liquid and saturated vapor, separated by a flat interface in an unbounded space, are in equilibrium. One would similarly expect a liquid drop, sitting on a flat substrate, to be in equilibrium with the vapor…
The design of artificial microswimmers is often inspired by the strategies of natural microorganisms. Many of these creatures exploit the fact that elasticity breaks the time-reversal symmetry of motion at low Reynolds numbers, but this…
This study investigates the hydrodynamics of droplet formation in a T-shaped cylindrical microfluidic device using micro-PIV experiments and CFD simulations. Devices of 150 micro-m internal diameter were fabricated from PDMS via a…
We studied how to charge droplets by induction and how to maximize this charge. In order to aim this objective, we developed an innovative device that avoids non-linear effects and that is able to charge liquids of different nature. The…
Weakly conducting dielectric liquid drops suspended in another dielectric liquid and subject to an applied uniform electric field exhibit a wide range of dynamical behaviors contingent on field strength and material properties. These…
We present a technique to locally and rapidly heat water drops in microfluidic devices with microwave dielectric heating. Water absorbs microwave power more efficiently than polymers, glass, and oils due to its permanent molecular dipole…
Introducing controlled fluid motion inside a droplet turns out to be of outstanding scientific importance. In this work, we suggest a new method of flow manipulation inside a sessile droplet by simply deploying a static charge produced by…
An electric field applied to a droplet impinging on a hydrophobic surface has an extensive variety of applications, including ant-icing, heat transfer enhancement, self-cleaning, droplet manipulation, and electrostatic spraying. The present…
Motivated by recent experiments on biomimetic membranes exposed to several aqueous phases, we theoretically study the morphology of a membrane in contact with a liquid droplet formed via aqueous phase separation. We concentrate on membranes…