An effective passive micromixer with shifted trapezoidal blades using wide Reynolds number range

In this paper, a novel micromixer design, called the shifted trapezoidal blades (STB) micromixer, has been designed and fabricated to provide high mixing efficiency even at low Reynolds number (Re) based on the combination of several mixing principles, including vortices, transversal flows and chaotic advection. Although the STB micromixer has 3D geometrical structure, it can be easily fabricated by one-step photolithography technique, using only one mask and two inclined exposures and an aluminum base with 15 inclines. We conducted intensive numerical study to evaluate the performance of the proposed STB micromixer using COMSOL Multiphysics package with a wide range of Reynolds number from 0.5 to 100. We have fabricated STB micromixers for testing and verification. Both experiment and simulation results demonstrated that the STB micromixer had stable mixing efficiency of 80% or above for Reynolds number values in the range from 0.5 to 100. The most effective mixing performance was achieved at Re=40 in which the STB micromixer had the highest mixing efficiency value (95%) and a moderate pressure drop Delta P=30.27 kPa. The proposed STB micromixer provided better mixing performance and smaller footprint compared to the previous micromixers presented in literatures. With a high mixing efficiency and the advantage of being easy to fabricate, the STB micromixer can be utilized in various microfluidic, point-of-care, point-of-need, central automatic diagnosis, and pre-treatment systems including sensor control systems. (C) 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.