The effect of vortex and injection position on the efficiency of micromixers

• Main Authors: Ching-Feng Wu, 吳青峰
• Other Authors: Zhi-Yang Wu
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/63900930997960465177

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 93 === 　In this thesis, we investigate a novel passive micromixer for better efficiency of mixing by tuning the structures of microfluidic channels with baffles and side injection. Furthermore, simulating the situation of the flows by software CFD-ACE+ provides the forecast of the mixing efficiency of the micromixer. 　In fabrication, SU-8 thick film photoresist is used to fabricate the mold of the micromixers on the silicon wafer by photolithography. Then, we transfer the mold structure of the micromixer to polydimethysiloxane (PDMS), and bond it with a cover layer of PDMS. Finally, the mixing performance has been demonstrated with an image analyzing software to quantify the gray value distribution in the exit section. 　To study the effect of structure on mixing, we change the size of baffles, the injection positions, the speed of the injected liquid and the length-width ratio of mixing rooms. Then, we compare the effect of those variables on the mixing efficiency of the micromixer. The numerical simulation and the experimental results show that the number and height of baffles dominates the mixing efficiency. Compare with other micromixers, the novel micromixer’s structure is simple and easy to fabricate. Thus, we may conclude that the present micromixers have better performance than others for the cases with Re＜50.