Enhancement of microfluidic mixing using reciprocal flow over baffles

• Main Authors: I-Cho Tseng, 曾奕焯
• Other Authors: Chih-Yang Wu
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/70468428311125632620

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 94 === In this work, we investigate the effects of baffles and periodic infusion on the mixing in a simple “T” channel. We used the SU-8 thick film photoresist on the silicon wafer to fabricate the structure of the micromixers by photolithogrphy. Casting of polydimethysiloxane（PDMS）was followed to mold the SU-8 pattern. Another PDMS with three holes was used to bond the first patterned PDMS together. Then, we obtained the experimental micromixer. The fluid flow system consists of the micromixer, pipes and two micro-syringe pumps. The two pumps supply the two kinds of fluids to the micromixer at time variable rates. An image capture system, including an optical microscope, a CCD camera, an image capture card and a personal computer, was set up. The visualization of the mixing process and the grayscale level of the mixing fluids are obtained by the system. Mixing efficiency was evaluated by calculating grayscale level of the fluids flowing through the micromixer. We also study mixing flow by the CFD-ACE+. Study the effect of infusion mode, fluid velocity and period by experiment and simulation. The results show that (i) the baffles can make the fluid mixing better, (ii) the mixing effect of reciprocal flow is better then steady flow, (iii) the mixing efficiency of the infusion in which both inlets keep the same velocity in phase and time ratio of infusion to withdraw is 2:1 is superior to the other infusions, (iv) the dependence of the mixing effect on Strouhal number does not show a general trend for the different infusions considered.