Numerical Simulation and Experimental Investigation of Three-dimensional (3-D) Vortex Micromixer for Rapidly Mixing Performance

• Main Authors: Nhat-vinh Bui, 裴日榮
• Other Authors: Jhih-long Lin
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/70896702472314468470

碩士 === 義守大學 === 機械與自動化工程學系碩士班 === 98 === Micromixers have been commonly employed in chemical or biological analysis for micro-total-analysis-systems (μ-TAS) applications. The mixing performance is a fundamentally important aspect of these devices since it is this mixing which generates the biochemical reactions necessary for their successful operation. This study investigates a three-dimensional (3-D) vortex active micromixer which utilizes pneumatic-driven membranes to generate a swirling flow in a mixing chamber for rapidly mixing performance. The vortex micromixer chip can be easily micromilled by CNC machine and fabricated by using MEMS technology. Computational fluid dynamics (CFD) simulations were also employed to investigate the mixing mechanism and to investigate the flow parameters. The swirling phenomenon in the active micromixer was predicted by the computational simulation of the microfluidic dynamics. Besides, a mixing index for quantifying the mixing performance was introduced to demonstrate the advantages of the vortex mixer. The 3-D vortex type micromixers are employed to induce the swirling flow field and to demonstrate a significant mixing performance. The mixing efficiency can be achieved as high as 95.0% in a short period of time. Meanwhile, the effect of the actuated frequency was also investigated. Numerical simulations and experimental observations indicated that the mixing efficiency increases with the increasing the driving frequency and completely mixing time drastically decrease with the increasing driving frequency. These results show that the proposed vortex micromixer chips can completely mix two samples. The simulated results were in reasonable agreement with the experimental results. Finally, the development of 3-D vortex active mixer may provide a powerful tool to integrate onto the microfluidic system.