Multidirectional Vortex Micromixer Utilizing a Curved Channel with Variable Cross-Sectional Circular Arc Mixing Chambers

Abstract

A planar passive multidirectional vortex micromixer with a simple geometry and easy fabrication has been proposed and developed. The design of the microchannel structure integrates the flow impact, Dean flow, and vortex mixing effect by periodically arranging jet channels and variable cross-sectional circular arc mixing chambers. The complex vortex flow facilitates the breaking of the original laminar barrier of the fluid, which leads to efficient mixing by increasing the contact area of fluid mediums and reducing the diffusion distance of fluid molecules. The micromixer has been fabricated using precision micromilling technology, and the fluid mixing process was observed using a microscope imaging system. The fluid mixing process was simulated using commercial software, and the obtained numerical simulation results are consistent with the experimental results. At a flow Reynolds number of 70, the mixing index of the micromixer with a radius ratio of 2.66 is about 72% at the end of the first mixing module, and after completion of the flow of three mixing modules, the mixing index of its outlet channel cross section can reach more than 95%. This micromixer's simple and reliable performance makes it ideal for flexible applications in micro total analysis systems.