Design and study on micromixer based on splitting and recombination mixing unit

XIE Haibo, ZHAO Xinbo
（State Key Laboratory of Fluid Power Transmission and Control, Zhejiang University, Hangzhou 310027, China）

Abstract: In order to realize quick and uniform mixing of micro scale, a splitting and recombination (SAR) mixing unit based on principle of fluid splitting and recombination was designed. Its branch angle θ was optimized by fluent and θ=70° was chosen as the optimized structure parameter. The SARmicromixer and compoundSARmicromixer(CSARmicromixer) were fabricated by a standard photolithographic technique which is much easier than the fabrication of some 3D micromixer. SARmicromixer, CSARmicromixer and slant block micromixer(SBM) were tested under Re=0.052~20, using the mixture of glycerol and water with volumetric ratio 5 ∶ 95(0.000 97 Pa·s). The test results show that, mixing length of SBM is larger than 20 mm when Re≥1.23, in contrast, maximum mixing of SARmicromixer is only 7.6 mm and CSARmicromixer which is the most efficient is about 5.4 mm. SARmicromixer and CSARmicromixer can be easily realized and integrated to microfluidic systems.
Key words: microfluid; passive micromixer; splitting and recombination(SAR)