An electro-coalescence chip for effective emulsion breaking in droplet microfluidics.

Breaking of an emulsion under an ac electric field.

By using microfluidic chips, we investigate the stability regarding coalescence of droplet pairs under an electric field as a function of drop separation and ac field intensity. Three different regimes are found: stable, coalescence, and partial merging. From this, we identify the two breaking scenarios of a one dimensional train of droplets: in one case the coalescence front propagates; in the...

A microfluidic method to study demulsification kinetics.

We present the results of experiments studying droplet coalescence in a dense layer of emulsion droplets using microfluidic circuits. The microfluidic structure allows direct observation of collisions and coalescence events between oil droplets dispersed in water. The coalescence rate of a flowing hexadecane-in-water emulsion was measured as a function of the droplet velocity and droplet concen...

Electro-Coalescence of an Aqueous Droplet at an Oil–Water Interface with an Investigation of Secondary Droplets Formation

A novel surgery-like strategy for droplet coalescence in microchannels.

We report an innovative and efficient surgery-like strategy for achieving the coalescence of surfactant-stabilized droplets in microchannels. As pairs of preformed droplets flow across a micro-lancet, with a suitable surface wettability, in a converging microchannel simultaneously, their surfaces are scratched by the micro-lancet, which causes temporarily local scattering of surfactants, and th...

Reactions in double emulsions by flow-controlled coalescence of encapsulated drops.

We demonstrate a microfluidic method to first generate double emulsion droplets containing two different inner drops, and to then control the internal coalescence of the encapsulated drops. The advantages of the core-coalescence method are illustrated by fabricating high viscosity particles and by demonstrating the dissolution of cell membranes.