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Microfluidic mixing: a review.

Lee CY, Chang CL, Wang YN, Fu LM - Int J Mol Sci (2011)

Bottom Line: In such devices, sample mixing is essentially achieved by enhancing the diffusion effect between the different species flows.Many mixers have been proposed to facilitate this task over the past 10 years.Accordingly, this paper commences by providing a high level overview of the field of microfluidic mixing devices before describing some of the more significant proposals for active and passive mixers.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Engineering, National Pingtung University of Science and Technology, Pingtung 912, Taiwan; E-Mail: leecy@mail.npust.edu.tw.

ABSTRACT
The aim of microfluidic mixing is to achieve a thorough and rapid mixing of multiple samples in microscale devices. In such devices, sample mixing is essentially achieved by enhancing the diffusion effect between the different species flows. Broadly speaking, microfluidic mixing schemes can be categorized as either "active", where an external energy force is applied to perturb the sample species, or "passive", where the contact area and contact time of the species samples are increased through specially-designed microchannel configurations. Many mixers have been proposed to facilitate this task over the past 10 years. Accordingly, this paper commences by providing a high level overview of the field of microfluidic mixing devices before describing some of the more significant proposals for active and passive mixers.

Show MeSH
Dimensions of the microfluidic system integrating a “Y” junction with channel width w, linear length of the periodic step s, and linear length of the zigzag microchannel L [64].
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f14-ijms-12-03263: Dimensions of the microfluidic system integrating a “Y” junction with channel width w, linear length of the periodic step s, and linear length of the zigzag microchannel L [64].

Mentions: Mengeaud et al. [64] presented a 100 μm wide zigzag microchannel integrating a “Y” inlet junction (Figure 14). The effect of the periodic step value s on the mixing efficiency was investigated in a series of experimental trials. The results indicated that for Re = 0.26, the mixing efficiency increased from 65% to 83.8% as the geometry ratio s/w was increased from 1 to 8. For low values of s/w, the number of angles increased, resulting in an increase in the effective width and a reduction in the effective length. For low Reynolds number flows, the most efficient zigzag configuration corresponding to s = 800 μm obtained a mixing efficiency of 83.8%. For Re = 267, the mixing efficiency increased rapidly to 98.6% as the geometry ratio was increased to 4, but reduced slightly to 88.1% as the geometry ratio was further increased, thus indicating the existence of an optimal zigzag geometry. In [65], Hong et al. presented a passive micromixer with a modified Tesla structure. In the proposed design, the species streams flowed close to the angled surface due to the Coanda effect, and this effect was used to guide the fluid streams to collide with one another. Mixing cells in opposite directions were then used to repeat the transverse dispersion caused by the flow impact. In the micromixer, one of the fluids was divided into two sub-streams and one of these two sub-streams was then merged with the second fluid stream from the main channel in the micromixer. The two streams were then mixed with the second sub-stream, resulting in a strong impact around the sub-channel of the micromixer. The results showed that the micromixer attained an excellent mixing performance at higher flow rates, and was characterized by a pressure drop of less than 10 kPa for flow rates of approximately 10 μL min−1. However, at lower flow rates, the mixer was constrained to the diffusive mixing regime, and hence the mixing performance was limited.


Microfluidic mixing: a review.

Lee CY, Chang CL, Wang YN, Fu LM - Int J Mol Sci (2011)

Dimensions of the microfluidic system integrating a “Y” junction with channel width w, linear length of the periodic step s, and linear length of the zigzag microchannel L [64].
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3116190&req=5

f14-ijms-12-03263: Dimensions of the microfluidic system integrating a “Y” junction with channel width w, linear length of the periodic step s, and linear length of the zigzag microchannel L [64].
Mentions: Mengeaud et al. [64] presented a 100 μm wide zigzag microchannel integrating a “Y” inlet junction (Figure 14). The effect of the periodic step value s on the mixing efficiency was investigated in a series of experimental trials. The results indicated that for Re = 0.26, the mixing efficiency increased from 65% to 83.8% as the geometry ratio s/w was increased from 1 to 8. For low values of s/w, the number of angles increased, resulting in an increase in the effective width and a reduction in the effective length. For low Reynolds number flows, the most efficient zigzag configuration corresponding to s = 800 μm obtained a mixing efficiency of 83.8%. For Re = 267, the mixing efficiency increased rapidly to 98.6% as the geometry ratio was increased to 4, but reduced slightly to 88.1% as the geometry ratio was further increased, thus indicating the existence of an optimal zigzag geometry. In [65], Hong et al. presented a passive micromixer with a modified Tesla structure. In the proposed design, the species streams flowed close to the angled surface due to the Coanda effect, and this effect was used to guide the fluid streams to collide with one another. Mixing cells in opposite directions were then used to repeat the transverse dispersion caused by the flow impact. In the micromixer, one of the fluids was divided into two sub-streams and one of these two sub-streams was then merged with the second fluid stream from the main channel in the micromixer. The two streams were then mixed with the second sub-stream, resulting in a strong impact around the sub-channel of the micromixer. The results showed that the micromixer attained an excellent mixing performance at higher flow rates, and was characterized by a pressure drop of less than 10 kPa for flow rates of approximately 10 μL min−1. However, at lower flow rates, the mixer was constrained to the diffusive mixing regime, and hence the mixing performance was limited.

Bottom Line: In such devices, sample mixing is essentially achieved by enhancing the diffusion effect between the different species flows.Many mixers have been proposed to facilitate this task over the past 10 years.Accordingly, this paper commences by providing a high level overview of the field of microfluidic mixing devices before describing some of the more significant proposals for active and passive mixers.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Engineering, National Pingtung University of Science and Technology, Pingtung 912, Taiwan; E-Mail: leecy@mail.npust.edu.tw.

ABSTRACT
The aim of microfluidic mixing is to achieve a thorough and rapid mixing of multiple samples in microscale devices. In such devices, sample mixing is essentially achieved by enhancing the diffusion effect between the different species flows. Broadly speaking, microfluidic mixing schemes can be categorized as either "active", where an external energy force is applied to perturb the sample species, or "passive", where the contact area and contact time of the species samples are increased through specially-designed microchannel configurations. Many mixers have been proposed to facilitate this task over the past 10 years. Accordingly, this paper commences by providing a high level overview of the field of microfluidic mixing devices before describing some of the more significant proposals for active and passive mixers.

Show MeSH