High-performance flow-focusing geometry for spontaneous generation of monodispersed droplets†
Abstract
A high-performance flow-focusing geometry for spontaneous generation of monodispersed droplets is demonstrated. In this geometry, a two-phase flow is forced through a circular orifice integrated inside a silicon-based microchannel. The orifice with its cusp-like edge exerts a ring of maximized stress around the flow and ensures controlled breakup of droplets for a wide range of flow rates, forming highly periodic and reproducible dispersions. The droplet generation can be remarkably rapid, exceeding 104 sā1 for water-in-oil droplets and reaching 103 sā1 for oil-in-