Passive micromixer with baffles distributed on both sides of microchannels based on the Koch fractal principle

2019 ◽  
Vol 95 (3) ◽  
pp. 806-812
Author(s):  
Xueye Chen ◽  
Yue Tian
Author(s):  
Siyue Xiong ◽  
Xueye Chen

Abstract In this paper, We arrange the obstacles based on the Koch fractal principle (OKF) in the micromixer. By changing the fluid flow and folding the fluid, a better mixing performance is achieved. We improve the mixing efficiency by placing OKF and changing the position of OKF, then we studied the influence of the number of OKF and the height of the micromixer on the mixing performance. The results show that when eight OKF are staggered in the microchannel and the height is 0.2 mm, the mixing efficiency of the OKF micromixer can reach 97.1%. Finally, we compared the velocity cross section and velocity streamline of the fluid, and analyzed the influence of OKF on the concentration trend. Through analysis, it is concluded that OKF can generate chaotic convection in the fluid, and enhance the mixing of fluids by generating vortices and folding the fluid. It can effectively improve the mixing efficiency of the micromixer.


2019 ◽  
Vol 27 (05) ◽  
pp. 1950141
Author(s):  
XUEYE CHEN ◽  
YUE TIAN ◽  
SHUAI ZHANG

In this paper, we focussed on the processing power of CO2 laser systems and the impact of scanning speed, scanning power and number of scans on the quality of microchannels. We created microchannels which are based on the Koch fractal principle through a flexible and low-cost CO2 laser system. The processing and manufacturing method of Koch fractal micromixer on polymethyl methacrylate (PMMA) substrate was also studied. The microchannel structure based on the Koch fractal principle can increase the contact area and mixing time of the fluid and improve the mixing efficiency of the micromixer. In the experiment, our speed is 2, 4 and 6[Formula: see text]mm/s, the number of scans is 2/3/4 times and the power is 4, 8 and 12[Formula: see text]W. As the power and number of scans increase and the speed decreases, the width and depth of the microchannel are changed more clearly, which contributes to the successful thermal bonding of the Koch fractal micromixer and avoids thermal bonding due to overvoltage. By comparing the experimental data, we found that the width and depth of the channel are ideal when the speed is 2[Formula: see text]mm/s, the number of scans is 4 and the power is 12[Formula: see text]W. Because of the lower cost of PMMA, the use of CO2 laser systems to fabricate microchannels on PMMA substrates will have broad application value, reduce cost and be easier to manufacture.


2017 ◽  
Vol 24 (6) ◽  
pp. 2627-2636 ◽  
Author(s):  
Xueye Chen ◽  
Shuai Zhang

Author(s):  
Yue Tian ◽  
Xueye Chen ◽  
Xiangwei Zeng ◽  
Xiangyang Wang ◽  
Xingxing Yu ◽  
...  

Micromixer is a kind of microfluidic chip for fast mixing and analysis. Mixing in a micromixer is usually a micron scale. At low Reynolds number, the fluid in the channel is laminar flow, which mainly depends on molecular diffusion as the main mixing mode. Fluid mixing in microchannels is very difficult, especially when the viscosity of the fluid is high. In this paper, we design a novel passive micromixer. The effects of fractal number, Koch fractal channel spacing, microchannel depth and cross-section shape on mixing efficiency were studied. Through a large number of numerical simulations, we continue to optimize the structure of the micromixer and improve the mixing efficiency. Finally, through the continuous optimization of the structure of the micromixer, the mixing efficiency of the micromixer can reach more than 95%.


RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12860-12865
Author(s):  
Siyue Xiong ◽  
Xueye Chen ◽  
Jinyuan Wang

Mixing performance of micromixers. (a) The voltage value is 0 V. (b) The voltage value is 3 V. (c) The voltage value is 10 V.


Author(s):  
Siyue Xiong ◽  
Xueye Chen

Abstract In this paper, we have designed a Koch fractal electroosmotic micromixer (KFEM). A low-voltage electroosmotic micromixer. In order to optimize the electrode position, Koch microchannel is designed according to the Koch fractal principle and the electrode pairs based on the fractal are arranged. Then the effect of electrode voltage, electrode distribution positions, the number of electrode pairs, two kinds of Koch fractal structures, Reynolds (Re) number and the frequency of alternating current (AC) on the mixing performance are studied. The results show that the mixing efficiency can reach 99% in a short time when the AC voltage is 1 V, the AC frequency is 12 Hz and the electroosmotic micromixer has two sets of electrode pairs.


2011 ◽  
Vol 5 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Yuwadee Boonyasit ◽  
Thitima Maturos ◽  
Assawapong Sappat ◽  
Apichai Jomphoak ◽  
Adisorn Tuantranont ◽  
...  

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