Numerical Research on Shape Optimization of Microchannels of Passive Micromixers

Abstract

This paper aims at shape optimization of microchannels of passive micromixers. Changing the microchannels shape is a very simple method to improve the species mixing efficiency in passive micromixers. Numerical analysis shows that the direction of flow velocity changes constantly due to the shape change of microchannels, which produces the chaotic convection and increases species mixing effectively. We have completed the simulation and analysis of six kinds of channel shapes, whose correctness is proved by several mixing experiments, and further numerically analyzed the advantages of the square wave micromixer. The simulation shows that square wave microchannels are the best for improving species mixing among six kinds of micromixers. According to adjusting the number of square wave units, a better mixing performance can be realized. It is a simple, flexible, and efficient method to improve the mixing performance of micromixers by shape optimization of microchannels. It can be demonstrated that the presented design method of shape optimization of microchannels is a simple, flexible, and efficient technology to improve species mixing in microfluidic devices. The shape optimization methodology has the potential for applications in system-level design of lab-on-a-chip.