Jet-wiping is a hydrodynamic method for controlling the liquid film thickness in a coating process. In industrial conditions, the jet is generally turbulent. When the jet wipes a liquid film, it usually induces violent film instability called splashing. The instability is characterized by the ejection of droplets from the runback flow. Consequently, it can degrade the final coating quality sinc...

Using a density functional method, we investigate the properties of liquid 4He droplets doped with atoms (Ne and Xe) and molecules ( SF6 and hydrogen cyanide). We consider the case of droplets having a quantized vortex pinned to the dopant. A liquid-drop formula is proposed that accurately describes the total energy of the complex and allows one to extrapolate the density functional results to ...

We report magnetic field tuning of the structure and Whispering Gallery Mode lasing from ferromagnetic nematic liquid crystal micro-droplets. Microlasers were prepared by dispersing a nematic liquid crystal, containing magnetic nanoparticles and fluorescent dye, in a glycerol-lecithin matrix. The droplets exhibit radial director structure, which shows elastic distortion at a very low external m...

A versatile microreactor protocol based on microfluidic droplets has been developed for on-line protein digestion. Proteins separated by liquid chromatography are fractionated in water-in-oil droplets and digested in sequence. The microfluidic reactor acts also as an electrospray ionization emitter for mass spectrometry analysis of the peptides produced in the individual droplets. Each droplet ...

Mercury metal dispersed spontaneously into the aqueous solution as micro-droplets when it came in quiescent contact with the solution. The self-dispersion was observed by means of the dynamic light scattering method, thermogravimetry and voltammetry. The mercury microdroplets generated in water had ca. 0.3 m in diameter. The diameter and the concentration of the droplets were stable. The conce...

We present a novel microfluidic approach for the generation of monodisperse oil droplets in water with ultra-low interfacial tensions. Using an oil-water-surfactant formulation under conditions close to the microemulsion phase transition, we actively controlled the surface tension at the liquid-liquid interface within the microfluidic device in order to produce monodisperse droplets. These drop...

Several applications exist for transiting liquid droplets through the near-Earth space environment. Numerical results are presented for the charging of liquid droplets of trimethyl pentaphenyl siloxane (DC705) in three different plasma environments: ionosphere, auroral, and geosynchronous Earth orbit (GEO). Nominal and high geomagnetic activity cases are investigated. In general, high levels of...

Here we demonstrate a novel concept of liquid-in-gas droplet microfluidics by using gas flow as the continuous phase for the production of liquid droplets. Within a specially configured co-flow microfluidic tubing device, a flow of liquid phase has been continuously dispersed into another outer stream of gas phase, producing discrete and monodisperse microdroplets. This process is robust and we...

The droplet dynamics and collisions after a liquid jet breakup have been experimentally studied in low gravity conditions. An experimental setup was designed in order to be used at the I.N.T.A. Drop Tower, which allows for 2.1 seconds of microgravity. The dynamics of distilled water jets injected into a rectangular tank was recorded by means of a high-speed video camera. Observations of the dro...

This paper describes a concept of concentration and binary separation of particles and its experimental confirmations for digital microfluidics where droplets are driven by the mechanism of electrowetting-on-dielectric (EWOD). As a fundamental separation unit, a binary separation scheme is developed, separating two different types of particles in one droplet into two droplets, one type each. Th...