Parametric study on mixing process in an in-plane spiral micromixer utilizing chaotic advection

Recent advances in the field of microfabrication have made the application of high-throughput microfluidics feasible. Mixing which is an essential part of any miniaturized standalone system remains the key challenge. This paper proposes a geometrically simple micromixer for efficient mixing for high-throughput microfluidic devices. The proposed micromixer utilizes a curved microchannel (spiral microchannel) to induce chaotic advection and enhance the mixing process. It is shown that the spiral microchannel is more efficient in comparison to a straight microchannel, mixing wise. The pressure drop in the spiral microchannel is only slightly higher than that in the straight microchannel. It is found that the mixing process in the spiral microchannel enhances with increasing the inlet velocity, unlike what happens in the straight microchannel. It is also realized that the initial radius of the spiral microchannel plays a prominent role in enhancing the mixing process. Studying different cross sections, it is gathered that the square cross section yields a higher mixing quality. [Display omitted] •A high-throughput micromixer is proposed and numerically characterized.•The investigated micromixer has a simple, in-plane structure.•The studied micromixer is energetically efficient; it causes a rather small pressure drop.•Different parameters such as Reynolds number of flow, the curvature and cross-section of the microchannel are investigated.•The dominant mixing mechanism of the spiral micromixer is chaotic advection which makes it high throughput and rapid.