Controlled retention of droplets and the enhancement of mass transfer in microchannel with multi-groove structure

Abstract

Abstract A simple and novel droplet-based microfluidic device with multi-groove structure has been developed to achieve stay-collision-transfer process of droplets. After summarizing the scaling law of droplet diameter and formation frequency with two phase flow rates, we got the optimum operating range of continuous phase flow. During the retention of droplet in groove, the existence of internal vortex was observed, which lead to the homogeneity of internal concentration field. For the process of solvent-microextraction with high phase ratio, due to multi-groove structure, the actual volume phase ratio in microchannel can be much smaller than injection phase ratio to improve extraction efficiency. And two-phase acid-base reaction and fluorescence extraction experiments further validate the enhancement of mass transfer process by this kind of microchannel.