Investigation of mixing characteristics in a novel SAR micromixer with locally overlapping V-shaped flow channels

Micromixers have been widely used in chemical reactions, drug testing, bio-analysis, and various other fields where achieving effective mixing is crucial for system performance. To enhance mixing efficiency, this study presents a novel micromixer design based on principles of separation diffusion and chaotic convection. It features a double-layer V-shaped channel and mixing chamber structure, along with an innovative approach of locally overlapping flow channels. The results demonstrate that this design induces fluid split and recombination within the flow channel, increasing contact areas between fluids. Furthermore, under the identical conditions, the overlapping of flow channels induces secondary flow separation, further enhancing mixing. Specifically, we observed a 9.39 % improvement in the mixing index when comparing before and after overlapping (when Re = 10). Moreover, when the Reynolds number exceeds 20, the mixing index at the outlet consistently surpasses 99 %, which is superior to most existing micromixers. These novel models significantly improve mixing efficiency at low Reynolds numbers and introduce a promising method for future research.