New 3D SAR micromixer based on 2D standard photolithographic technique

A splitting and recombination-type micromixer (SAR-micromixer) based on the principle of fluid splitting, rearranging and recombination was optimised by the computational fluid dynamics (CFD) technique, fabricated and tested experimentally. Based on the split ratio, the mixing efficiency and the average pressure gradient, the branch angle of 70° and the zero straight channel length were chosen as the optimised structure parameters for an SAR mixing unit. The SAR-micromixer was fabricated by a standard photolithographic technique that is much easier than the fabrication of some 3D micromixer. To comprehensively evaluate the SAR-micromixer, its performance was compared with the straight channel micromixer (SCM) and the slant block micromixer (SBM) at various Reynolds numbers using dyed glycerol−water mixture fluids with various viscosities. Mixing experiments indicates that the mixing length of SAR-micromixer is much smaller than that of SCM and SBM; it is robust and efficient from slight viscous (0.00097 Pa s) to highly viscous (0.3792 Pa s) fluids.