Hydrodynamic influences of artificial cilia beating behaviors on micromixing

In microfluidic applications, the beating behaviors of artificial cilia determine the efficacy of artificial cilia-based micromixers. The same is especially true when the rapid mixing of two fluids with artificial cilia actuation is highly demanded in many biomedical and analytical chemistry contexts. The transient hydrodynamics induced by the diversely dynamic motions of artificial cilia and the associated interactions with surrounding flow fields engender speculation for identifying an ideal trajectory of artificial cilia in an effective micromixing process. Intrigued by this motive, we selected four distinct beating behaviors for comparing micromixing performance. The tangled interactions between the induced flow by artificial cilia and the imposing flow through syringe pump actuation were also documented. A parametric study was performed via a micro-particle image velocimetry technique to elucidate the synergic effects contributed by dominant parameters, such as the beating speed and patterns of artificial cilia. Depth-resolved induced flow patterns through artificial cilia actuation were provided using a computational fluid dynamic method to elucidate how micromixing was achieved in a whole-field point of view. A new microscale flow mixing concept was therefore initiated and demonstrated in this work to extend the current practices related to artificial cilia-based micromixers for highly viscous flow manipulation applications. (C) 2015 Elsevier B.V. All rights reserved.