FLOW VISUALIZATION STUDIES ON TWO-PHASE FLOWS IN MICROFLUIDICS

摘要

Microfluidics has attracted considerable attention for the past few decades with the advance of microdevices in many areas of applications, including lab-on-a-chip, printing, power generation, etc. In designing such microdevices, flow visualization studies play a major role, which are mainly associated with transport phenomena of solid-liquid, liquid-liquid (or bi-slug), and gas-liquid two-phase flows. As for solid-liquid two-phase flows, we extensively review the flow visualization studies regarding inertial-microfluidic lateral migration of particles, which provides a new tool for separation, sorting, extraction, and focusing of microparticles. The flow visualization studies on liquid-liquid two-phase flow will be discussed, which considers the velocity vector fields of the dispersed and continuous phases in microchannel platforms. The flow visualization studies on gas-liquid flows are briefly overviewed in conjunction with pressure drop, void fraction, bubble speed, etc.