Step-emulsification in nanofluidic device
Abstract
In this paper we present a comprehensive study of the step-emulsification process for high-throughput production of (sub-)m-size monodisperse droplets. The microfluidic device combines a Hele-Shaw nanofluidic cell with a step-like outlet to a deep and wide reservoir. The proposed theory based on Hele-Shaw hydrodynamics provides the quasi-static shape of the free boundary between the disperse liquid phase engulfed by the co-flowing continuous phase prior to transition to oscillatory step-emulsification at low enough capillary number. At the transition the proposed theory anticipates a simple condition for critical capillary number as a function of the Hele-Shaw cell geometry. The transition threshold is in excellent agreement with experimental data. A simple closed-form expression for the size of the droplets generated in step-emulsification regime derived using simple geometric arguments also shows a very good agreement with the experimental results.
Cite
@article{arxiv.1405.1923,
title = {Step-emulsification in nanofluidic device},
author = {Z. Li and A. M. Leshansky and L. M. Pismen and P. Tabeling},
journal= {arXiv preprint arXiv:1405.1923},
year = {2014}
}