Abstract
This study investigated micromixers formed by a T-junction and a mixing channel consisting of serial modules formed by appropriately arranging the subsections with right shifted T-shaped, left shifted T-shaped and square cross-sections. The T-shaped cross-sections are constructed by protrusions and indentations on the channel wall. The variation of shape and size of the channel cross-section may induce a strong swirl structure of flow to enhance fluid mixing. Four parameters (the lengths of the three aforementioned subsections and the sequence of modules) were selected to optimize the micromixer, and computational fluid dynamics (CFD) together with Taguchi method was applied to select the values of the parameters. Then, the micromixer was fabricated by a lithography process and the mixing of pure DI water and a solution of Rhodamine B in DI water in the micromixer was observed by using a confocal spectral microscope imaging system. The numerical and experimental results, compared to those of a straight channel with the same hydrodynamic diameter, show that the novel micromixer with the deliberately designed geometry with a hydrodynamic diameter equal to 120 μm enhances fluid mixing efficiently at relatively low Reynolds numbers (0.01–10), corresponding to the mean velocities from 0.000081 to 0.081 m/s. The effects of the four parameters on fluid mixing in the proposed micromixer are examined by CFD simulation.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Boss J (1986) Evaluation of the homogeneity degree of a mixture. Bulk Solids Handl 6:1207–1215
Chen H, Meiners J-C (2004) Topologic mixing on a microfluidic chip. Appl Phys Lett 84:2193–2195
Chen JJ, Lai YR, Tsai RT, Lin JD, Wu C-Y (2011) Crosswise ridge micromixers with split and recombination helical flows. Chem Eng Sci 66:2164–2176
Cheng YP, Qu ZG, Tao WQ, He YL (2004) Numerical design of efficient slotted fin surface based on the field synergy principle. Numer Heat Transfer A 45:517–538
Engler M, Kockmann N, Kiefer T, Woias P (2004) Numerical and experimental investigations on liquid mixing in static micromixers. Chem Eng J 101:315–322
Hossain S, Ansari MA, Kim KY (2009) Evaluation of the mixing performance of three passive micromixer. Chem Eng J 150:492–501
Hsiao K-Y, Wu C-Y, Huang Y-T (2014) Fluid mixing in a microchannel with longitudinal vortex generators. Chem Eng J 235:27–36
Kim DS, Lee SH, Kwon TH, Ahn CH (2005) A serpentine laminating micromixer combining splitting/recombination and advection. Lab Chip 5:739–747
Lee SW, Lee SS (2008) Rotation effect in split and recombination micromixing. Sens Actuator B Chem 129:364–371
Lee C-Y, Wang W-T, Liu C-C, Fu L-M (2016) Passive mixers in microfluidic systems: a review. Chem Eng J 288:146–160
Liu K, Yang Q, Chen F, Zhao Y, Meng X, Shan C, Li Y (2015) Design and analysis of the cross-linked dual helical micromixer for rapid mixing at low Reynolds number. Microfluid Nanofluid 19:169–180
Nguyen N-T, Wu Z (2005) Micromixers—a review. J Micromech Microeng 15:R1–R16
Park J-Y, Kim Y-D, Kim S-R, Han S-Y, Maeng J-S (2008) Robust design of an active micro-mixer based on the Taguchi method. Sens Actuators B Chem 129:790–798
Rani SA, Pitts B, Stewart PS (2005) Rapid diffusion of fluorescent tracers into Staphylococcus epidermidis biofilms visualized by time lapse microscopy. Antimicrob Agents Chemother 49:728–732
Schönfeld F, Hessel V, Hofmann C (2004) An optimised split-and-recombine micro-mixer with uniform ‘chaotic’ mixing. Lab Chip 4:65–69
Simonnet C, Groisman A (2005) Chaotic mixing in a steady flow in a microchannel. Phys Rev Lett 94:134501
Stroock AD, Dertinger SKW, Ajdari A, Mezic I, Stone HA, Whitesides GM (2002) Chaotic mixer for microchannel. Science 295:647–651
Taguchi G, Yokoyama T, Wu Y (1993) Taguchi methods: design of experiments. ASI Press, Tokyo
Viktorov V, Nimafar M (2013) A novel generation of 3D SAR-based passive micromixer: efficient mixing and low pressure drop at low Reynolds number. J Micromech Microeng 23:1–13
Xia HM, Wan SYM, Shu C, Chew YT (2005) Chaotic micromixers using two-layer crossing channels to exhibit fast mixing at low Reynolds numbers. Lab Chip 5:748–755
Yang JT, Huang K-J, Lin Y-C (2005) Geometric effects on fluid mixing in passive grooved micromixers. Lab Chip 5:1140–1147
Yoo W-S, Go JS, Park S, Park S-H (2012) A novel effective micromixer having horizontal and vertical weaving flow motion. J Micromech Microeng 22:1–9
Acknowledgments
We sincerely appreciate the Center for Micro/Nano Science and Technology and the University Center for Bioscience and Biotechnology in National Cheng Kung University for the accesses of fabrication and experimental equipments.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Huang, SW., Wu, CY., Lai, BH. et al. Fluid mixing in a swirl-inducing microchannel with square and T-shaped cross-sections. Microsyst Technol 23, 1971–1981 (2017). https://doi.org/10.1007/s00542-016-2952-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00542-016-2952-x