A novel design for 3D passive micromixer based on Cantor fractal structure

In this paper, we design a three-dimensional micromixer based on Cantor structure. According to the principle of enhancing chaotic advection and folding fluid, it can produce better mixing performance. First we design the fractal obstacle based on the Cantor structure. We combine the obstacle with the T type microchannel. And we get multiple combinations of microchannel. We use multi-physics field simulation software COMSOL 5.2a to simulation, which is based on finite element theory. Then we analyze the mixing performance of the Imitate Cantor structure micromixer, x stands for the height of the micromixer (ICSM_x) in the Re of 0.01–100 and explain the mechanisms of mixing enhancement in each structure. We compare the effect of the height of the obstacles, the effect of the spacing between the obstacles, and the effect of fractal obstacles series. By comparison, when Re is more than 50 or less than 0.1, the mixing efficiency of all micromixer can reach above 90%. Finally, we obtain a best micromixer, called Imitate Cantor structure micromixer with height 600 µm (ICSM₆₀₀). The minimum mixing efficiency of ICSM₆₀₀ can reach 85%, so the mixing efficiency of ICSM₆₀₀ is clearly better than others.