To integrate efficient mixing functions inside small chips with variable Reynolds numbers, this study developed a strategy for designing micromixers by increasing the concentration difference through matching contact surfaces based on Fick's law and Einstein's equation for Brownian motion. Subsequently, the Coanda effect was extended by analyzing the flow direction of the fluid over the channel surface and abstracting four functions from specific microchannel modules. These functions were used to predict and modulate the concentration gradient and construct the micromixer. Two three-dimensional structures of passive micromixers were designed using four functional modules to rotate and adjust the fluid interface. A three-dimensional Navier-Stokes system of equations was used for numerical analysis, and a micromixer was constructed via soft lithography for experimental verification. The experimental and simulation results showed that the designed micromixer consistently exhibits a mixing efficiency of 94%-99% at 3.3 mm, which is 22 times the hydraulic diameter length, for Reynolds numbers ranging from 0.1 to 100. This demonstrates a clear advantage over existing methods at an equal hydraulic diameter. Furthermore, the structure is easy to integrate on a chip, indicating the superiority of the modular design.
关键词
微流控微混合器分裂合并旋转效应片上实验室
Keywords
microfluidicsmicromixersplit and recombinationrotation effectlab on a chip
references
JAHN A, STAVIS S M, HONG J S, et al. Microfluidic mixing and the formation of nanoscale lipid vesicles[J]. ACS Nano, 2010, 4(4): 2077-2087. doi: 10.1021/nn901676xhttp://dx.doi.org/10.1021/nn901676x
BAYAREH M, ASHANI M N, USEFIAN A. Active and passive micromixers: a comprehensive review[J]. Chemical Engineering and Processing-Process Intensification, 2020, 147: 107771. doi: 10.1016/j.cep.2019.107771http://dx.doi.org/10.1016/j.cep.2019.107771
OH K W, LEE K S, AHN B, et al. Design of pressure-driven microfluidic networks using electric circuit analogy[J]. Lab on a Chip, 2012, 12(3): 515-545. doi: 10.1039/c2lc20799khttp://dx.doi.org/10.1039/c2lc20799k
ZHAO S G, HUANG P H, ZHANG H Y, et al. Fabrication of tunable, high-molecular-weight polymeric nanoparticles via ultrafast acoustofluidic micromixing[J]. Lab on a Chip, 2021, 21(12): 2453-2463. doi: 10.1039/d1lc00265ahttp://dx.doi.org/10.1039/d1lc00265a
AZIMI N, RAHIMI M, ZANGENEHMEHR P. Numerical study of mixing and mass transfer in a micromixer by stimulation of magnetic nanoparticles in a magnetic field[J]. Chemical Engineering & Technology, 2021, 44(6): 1084-1093. doi: 10.1002/ceat.202000030http://dx.doi.org/10.1002/ceat.202000030
DING H H, ZHONG X T, LIU B, et al. Mixing mechanism of a straight channel micromixer based on light-actuated oscillating electroosmosis in low-frequency sinusoidal AC electric field[J].Microfluidics and Nanofluidics, 2021, 25(3): 1-15. doi: 10.1007/s10404-021-02430-1http://dx.doi.org/10.1007/s10404-021-02430-1
MONDAL B, MEHTA S K, PATOWARI P K, et al. Numerical study of mixing in wavy micromixers: comparison between raccoon and serpentine mixer[J]. Chemical Engineering and Processing-Process Intensification, 2019, 136: 44-61. doi: 10.1016/j.cep.2018.12.011http://dx.doi.org/10.1016/j.cep.2018.12.011
FERNÁNDEZ-MAZA C, FALLANZA M, GÓMEZ-COMA L, et al. Performance of continuous-flow micro-reactors with curved geometries. Experimental and numerical analysis[J]. Chemical Engineering Journal, 2022, 437: 135192. doi: 10.1016/j.cej.2022.135192http://dx.doi.org/10.1016/j.cej.2022.135192
HARRSON S, SANTANA, CALVO P V C, et al. Design, optimization and scale-up of a new micromixer design based on plate column for organic synthesis[J]. Chemical Engineering Journal, 2022, 446: 137159. doi: 10.1016/j.cej.2022.137159http://dx.doi.org/10.1016/j.cej.2022.137159
ZHANG H, YANG SH, CHUAI R Y, et al. Performance optimization of chaotic flow micromixer[J]. Opt. Precision Eng., 2022, 30(3): 286-295.(in Chinese). doi: 10.37188/OPE.20223003.0286http://dx.doi.org/10.37188/OPE.20223003.0286
RAZA W, HOSSAIN S, KIM K Y. Effective mixing in a short serpentine split-and-recombination micromixer[J]. Sensors and Actuators B: Chemical, 2018, 258: 381-392. doi: 10.1016/j.snb.2017.11.135http://dx.doi.org/10.1016/j.snb.2017.11.135
HASHMI A, XU J. On the quantification of mixing in microfluidics[J]. SLAS Technology, 2014, 19(5): 488-491. doi: 10.1177/2211068214540156http://dx.doi.org/10.1177/2211068214540156