A planar labyrinth micromixer
Date of Original Version
Rapid mixing of two fluids in microchannels has posed an important challenge to the development of many integrated lab-on-a-chip systems. In this paper, we present a planar labyrinth micromixer (PLM) to achieve rapid and passive mixing by taking advantage of a synergistic combination of the Dean vortices in curved channels, a series of perturbation to the fluids from the sharp turns, and an expansion and contraction of the flow field via a circular chamber. The PLM is constructed in a single soft lithography step and the labyrinth has a footprint of 7.32 mm x 7.32 mm. Experiments using fluorescein isothiocyanate solutions and deionized water demonstrate that the design achieves fast and uniform mixing within 9.8 s to 32 ms for Reynolds numbers between 2.5 and 30. Compared to the mixing in the prevalent serpentine design, our design results in 38% and 79% improvements on the mixing efficiency at Re=5 and Re=30 respectively. An inverse relationship between mixing length and mass transfer Péclet number (Pe) is observed, which is superior to the logarithmic dependence of mixing length on Pe in chaotic mixers. Having a simple planar structure, the PLM can be easily integrated into lab-on-a-chip devices where passive mixing is needed. © 2010 by ASME.
2010 14th International Heat Transfer Conference, IHTC 14
Cogswell, Jeremy T., Peng Li, and Mohammad Faghri. "A planar labyrinth micromixer." 2010 14th International Heat Transfer Conference, IHTC 14 4, (2010): 677-681. doi:10.1115/IHTC14-22957.