Design and evaluation of a 3D multi-manifold micromixer realized by a double-Archimedes-screw for rapid mixing within a short distance

Abstract

Recent developments in 3D micromixers promise to accomplish satisfactory mixing for applications in microchemical process, biomicrofluidic analyses, μ-TAS, etc. However, the complicated 3D architecture employed to ensure thorough mixing might reduce fluid circulation due to the space for fluid flowing becomes narrow. In this study, we developed a single 3D multi-manifold micromixer composed of a double-Archimedes-screw for rapidly mixing within a short distance. Archimedes screw is well known for its fluid circulation under stable flow. The mixing strategy is based on split-and-recombination for increasing the interfacial area, and the 3D flow rotation for generating omnidirectional momentum-changes during the fluid propagation. With the spiral conformation, the Archimedes-screw micromixer (ASM) can substantially enhance fluid circulation. Numerical simulations used to help to design the optimal screw-turn show that satisfactory mixing efficiency can achieve at the distance of approximately twice the microchannel width. The ASM characteristics, such as pressure loss, ratio of cross-sections, and Reynolds number (Re) were evaluated. Experimental demonstration by an ASM fabricated by two-photon stereolithography showed mixing result in good agreement with the simulation findings.