Driven by the advancement of the "lab-chip" concept, a new beating behavior of artificial cilia was identified to meet the demands on rapid and complete fluid mixing in miniaturized devices. This beating behavior is characterized by an in-plane asymmetric motion along a modified figure-of-eight trajectory. A typically symmetric figure-of-eight motion was also tested for comparison. Results showed that with this new beating behavior, the mixing efficiency for complete mixing is 1.34 times faster than that with the typical figure-of-eight motion. More importantly, the required beating area was only approximately two-thirds of that in the typical figure-of-eight motion, which is beneficial for more compact designs of various "lab-chip" applications. The unique planar asymmetric motion of the artificial cilia, which enhanced the magnitudes of the induced three-dimensional (3D) flow, was identified by micro-particle image velocimetry (μPIV) measurement and numerical modeling as a major contributor in enhancing microscale mixing efficiency. Quantitatively, 3D vortical flow structures induced by the artificial cilia were presented to elucidate the underlying interaction between the artificial cilia and the surrounding flow fields. With the presented quantification methods and mixing performance results, a new insight is provided by the hydrodynamic advantage of the presented micromixing concept on efficiently mixing highly viscous flow streams at microscale, to leverage the attributes of artificial cilia in the aspect of microscale flow manipulation.
All Science Journal Classification (ASJC) codes
- Computational Mechanics
- Mechanics of Materials
- Physics and Astronomy(all)
- Fluid Flow and Transfer Processes