A planar labyrinth micromixer
Document Type
Conference Proceeding
Date of Original Version
12-1-2010
Abstract
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.
Publication Title, e.g., Journal
2010 14th International Heat Transfer Conference, IHTC 14
Volume
4
Citation/Publisher Attribution
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.