Design, evaluation, and optimization of a new micromixer based on three-dimensional multilaminar flow

A micromixer is a crucial component in microfluidic systems, playing a significant role in achieving efficient mixing of fluids at the microscale. This paper introduces a three-dimensional multilaminar flow micromixer (MLFM) that enables perfect mixing across a wide range of Reynolds numbers from 0.1 to 50. The MLFMs effectively enhance the interfacial contact area between two mixed fluids by efficiently splitting and recombining, as compared to the conventional 3D E-shaped micromixer. This results in the formation of multiple layers of fluid that overlap under stable laminar flow, ultimately leading to superior mixing performance. Specifically, MLFM-1 with a wedge-shaped branching channel and a spatial structure at the separation point of two flows exhibits exceptional mixing performance exceeding 93 % mixing index across all Reynolds numbers in this work. Considering both the mixing effect and pressure drop comprehensively, three branching channels in each mixing unit have been proved as the optimal choice to enhance the quality of mixing. The type of multiple laminar flow micromixer has the potential for extension to achieve the necessary components of an integrated microfluidic chip system.