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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.

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Schematic diagram of micro T-mixer [60].
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f10-ijms-12-03263: Schematic diagram of micro T-mixer [60].

Mentions: In miniaturized flow systems with Reynolds numbers varying from 2 to 100, flow structures can be artificially induced, assisting flow segmentation through inertia effects. In the zigzag channel considered in [58], segmentation was achieved through shear forces. The results showed that mixing was achieved within 1 s for fluid flows with a Reynolds number of 33 for two fluid streams flowing alongside each other in a microchannel of dimensions 300 μm × 600 μm × 100 mm containing 80 zigzags [58]. Another example of mixing via inertia forces was demonstrated by Scampavia et al. [59] who fabricated a coaxial mixer containing an inner core liquid stream with a low flow rate and an outer flow stream with a higher flow rate. The authors showed that the design achieved an acceptable mixing result within 55 ms for fluid flows with a Reynolds number of 5. Wong et al. [60] presented a micro T-mixer fabricated on a silicon substrate and bonded to a Pyrex glass plate (Figure 10). The experimental results revealed that a mixing channel with a hydraulic diameter of 67 μm and an applied pressure of 5.5 bar was sufficient to achieve complete species mixing in less than 1 ms after the initial contact between the two species flows with Reynolds numbers of 400–500. Buchegger et al. [13] proposed a horizontal multi-lamination micromixer based on wedge shaped inlet channels. The experimental results revealed highly uniform fluid mixing in the low millisecond second range. Tofteberg et al. [14] fabricated a passive micromixer that made a controlled 900 rotation of a flow cross-section followed by a split into several channels (Figure 11). The flow in each of these channels was rotated a further 90° before a recombination doubled the interfacial area between the two fluids, and the process was repeated the desired degree of mixing was achieved.


Microfluidic mixing: a review.

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

Schematic diagram of micro T-mixer [60].
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f10-ijms-12-03263: Schematic diagram of micro T-mixer [60].
Mentions: In miniaturized flow systems with Reynolds numbers varying from 2 to 100, flow structures can be artificially induced, assisting flow segmentation through inertia effects. In the zigzag channel considered in [58], segmentation was achieved through shear forces. The results showed that mixing was achieved within 1 s for fluid flows with a Reynolds number of 33 for two fluid streams flowing alongside each other in a microchannel of dimensions 300 μm × 600 μm × 100 mm containing 80 zigzags [58]. Another example of mixing via inertia forces was demonstrated by Scampavia et al. [59] who fabricated a coaxial mixer containing an inner core liquid stream with a low flow rate and an outer flow stream with a higher flow rate. The authors showed that the design achieved an acceptable mixing result within 55 ms for fluid flows with a Reynolds number of 5. Wong et al. [60] presented a micro T-mixer fabricated on a silicon substrate and bonded to a Pyrex glass plate (Figure 10). The experimental results revealed that a mixing channel with a hydraulic diameter of 67 μm and an applied pressure of 5.5 bar was sufficient to achieve complete species mixing in less than 1 ms after the initial contact between the two species flows with Reynolds numbers of 400–500. Buchegger et al. [13] proposed a horizontal multi-lamination micromixer based on wedge shaped inlet channels. The experimental results revealed highly uniform fluid mixing in the low millisecond second range. Tofteberg et al. [14] fabricated a passive micromixer that made a controlled 900 rotation of a flow cross-section followed by a split into several channels (Figure 11). The flow in each of these channels was rotated a further 90° before a recombination doubled the interfacial area between the two fluids, and the process was repeated the desired degree of mixing was achieved.

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