Design of Efficient Electroosmotic Micromixer

Author(s):  
Yogendra M. Panta ◽  
Param C. Adhikari

Micro-bio/chemical applications in a μTAS (Micro Total Analysis Systems) require rapid and uniform mixing of a number of fluid streams that carries bio/chemical species in the solution. An electro osmotic mixer from COMSOL model library is taken as a main model from which other alterations are designed for optimization. The circular, square and elliptical mixers were modeled to see the variation in the mixing. We analyzed the mixing process by varying the mixing shape, concentration, mixing channel width and electrode pairs. Concentration variance at the outlet over time was studied to determine the extent of mixing.

Author(s):  
Yogendra M. Panta ◽  
Param C. Adhikari ◽  
Sanket Aryal

Micro Total Analysis Systems (μTAS) require rapid yet homogeneous mixing of a number of fluid streams that carry bio/chemical species in the solution. Current analysis has been continued from our previously published work [1]. New models were designed by rendering some particular fluid and geometric variables from the original design and then analyzed for the degree of mixing effectiveness. A careful placement of obstacles in the mixing zone of the model and the electrodes in it showed enhancement in mixing performance. In addition, models with varied geometrical parameters such as converging inlet and diverging outlet yielded even better mixing capabilities. Concentration variances over time at the outlet were simultaneously compared in all models for mixing. Also average concentration was tracked over time so as to confirm the uniformity in mixing. The concentration variances at the outlet have been dramatically observed to be reduced by a factor of at least 10 from our designs as reported earlier [1].


2021 ◽  
pp. 129859
Author(s):  
Tao Tang ◽  
Yapeng Yuan ◽  
Yaxiaer Yalikun ◽  
Yochiroh Hosokawa ◽  
Ming Li ◽  
...  

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Damena D. Agonafer ◽  
J. Yeom ◽  
M. A. Shannon

Microposts are utilized to enhance heat transfer, adsorption/desorption, and surface chemical reactions. In a previous study [Yeom et al., J. Micromech. Microeng., 19, p. 065025 (2009)], based in part on an experimental study, an analytical expression was developed to predict the pressure drop across a microchannel filled with arrays of posts with the goal of fabricating more efficient micro-total analysis systems (µTAS) devices for a given pumping power. In particular, a key figure of merit for the design of micropost-filled reactors, based on the flow resistance models was reported thus providing engineers with a design rule to develop efficient µTAS devices. The study did not include the effects of the walls bounding the microposts. In this paper, a three-dimensional computational fluid dynamics model is used to include the effects of three-dimensionality brought about by the walls of the µTAS devices that bound the microposted structures. In addition, posts of smaller size that could not be fabricated for the experiments were also included. It is found that the two- and three-dimensional effects depend on values of the aspect ratio and the blockage ratios. The Reynolds number considered in the experiment that ranged from 1 to 10 was extended to 300 to help determine the range of Re for which the FOM model is applicable.


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