JP2009233561A - Micromixer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a micromixer that is compact and yet can advantageously enhance its mixing efficiency. <P>SOLUTION: The micromixer is constituted of a stack of a base plate having a plurality of feed ports from which fluids are fed, a distribution plate having at least one distribution channel per fluid and at least two distribution channels in total through which the fluids individually flow from each of the plurality of feed ports, a junction plate having at least one mixing channel that causes the fluids from each of the distribution channels to merge and mix together, and a top plate having a storage member that stores the mixed fluids. The distribution channels are equipped with main channels each parallelly extending between the neighboring distribution channels, and a plurality of branch channels each branching from the main channels and extending toward the opposite main channels respectively. The branch channels are disposed in such a manner that at least the end part of a branch channel of one of the neighboring distribution channels and at least the end part of a branch channel of the other of the neighboring distribution channels are alternately arrayed. The mixing channel extends in the direction of crossing all of the branch channels each disposed between the neighboring distribution channels, and introduces the fluids from the intersections with the individual branch channels. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is carried out by using a microfluidic device having a microstructure represented by a microreactor represented by μ-TAS (abbreviation of Micro Total Analysis System) in Europe and Lab-on-A-chip in the United States, for example. The present invention relates to a novel micromixer that enables mixing and stirring of a plurality of types of microfluids.

As a conventional technique related to the structure of a micromixer, for example, as described in Patent Document 1, a micromixer using a substrate in which a micro flow path is formed in a Y shape, or as described in Patent Document 2, A micromixer using a substrate having a T-shaped micro flow path is known.
JP 2006-205080 A JP 2006-7063 A

  In the micromixer in which these Y-shaped and T-shaped microchannels are formed, the flow is in a laminar flow state. Therefore, the solution supplied from the two supply ports becomes a two-layer flow in the microchannel, and the stirring / mixing of these two layers is governed by diffusion. Therefore, it is difficult to perform complete mixing in a short time. There is a problem that time is required.

  For the purpose of shortening the mixing time, as a means for increasing the area of the interface between the two liquids, for example, the flow of two layers is divided into a large number on a plane to form a large number of laminar flows. The method of improving stirring efficiency is mentioned. However, since such a method divides the flow into a large number, it is necessary to form a complicated multi-channel using a precision processing technique, which is not preferable because the processing cost increases. In addition, even when multi-channel is used, since it is a micro-channel formed in a plane, the fluid is still laminar and stirring / mixing is governed by diffusion. There was room for improvement. In addition, in order to form a multi-channel on a plane, a large substrate area is required to some extent, which has a problem that it cannot be used for the purpose of downsizing the entire micromixer.

Furthermore, other micromixer conventional technologies include a mixer using a porous filter, a multilayer mixer, a mixer that performs mixing by chaotic mixing using a spiral flow of fluid, and a pseudo turbulent flow generated by colliding with a flow path wall. A wide variety of micromixers have been reported, such as mixers using ultrasonic waves, ultrasonic waves, electric fields, magnetic fields, and micromixers using micro stirrers (for example, Patent Document 3). Since the road pattern and the device configuration are complicated, there is a problem that it is expensive and not suitable for mass production.
JP 2006-320877 A

  The present invention has been made in view of the above-described problems, and it is an object of the present invention to provide a micromixer that can advantageously increase mixing efficiency while being small in size.

To achieve the above object, a micromixer according to the present invention includes a base plate having a plurality of supply ports to which fluid is supplied, at least one distribution for each fluid through which the fluid from each supply port passes, and a total of at least three distributions. A distribution plate having a flow path, a merge plate having at least two mixing flow paths for merging and mixing fluid from each distribution flow path, and a top plate having a reservoir for guiding and storing the mixed fluid are stacked. The distribution flow path includes a main flow path extending in parallel between adjacent distribution flow paths, and a plurality of branch flow paths branched from the main flow path and extending toward the opposed main flow paths. The channel has an arrangement in which at least the tip of the branch channel of one adjacent distribution channel and at least the tip of the branch channel of the other distribution channel are alternately arranged, and the mixing channel is between the adjacent distribution channels. That extends in a direction transverse to all the tributary flow paths, guide the fluid from the intersection of the respective branch flow paths, among the distribution channel, the two widths of the main channel of the distribution channel, which is sandwiched between the distribution channel Is larger than the width of the main flow path of the other distribution flow path .

  Moreover, it is preferable that the main channel and the branch channel of the distribution channel extend linearly.

  Furthermore, the mixing channel preferably extends linearly.

  In addition, the width of the main channel of the distribution channel sandwiched between the distribution channels is preferably in the range of 120 to 300% of the width of the main channel of the other distribution channels, more preferably 150. It is in the range of ~ 200%. The “width of the main channel” here refers to the distance measured in the direction perpendicular to the extending direction in the main channel.

  In addition, it is preferable that a plurality of stacked bodies each including a base plate, a distribution plate, a merging plate, and a top plate are stacked.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the micromixer which can raise mixing efficiency markedly.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 3 show the main configuration of a micromixer according to the present invention. 1 is a top view of a representative micromixer according to the present invention, FIG. 2 is a side sectional view of the micromixer shown in FIG. 1, and FIG. 3 is an exploded view of the macromixer shown in FIG. . 4 to 6 are enlarged views respectively showing a base plate, a distribution plate, and a confluence plate of the micromixer shown in FIGS. FIGS. 7A to 7C are diagrams schematically illustrating a fluid mixing pattern when the fluid is guided from the distribution plate to the junction plate by the microplate of the present invention. FIG. 8 is an enlarged view of the top plate of the micromixer shown in FIGS.

  The illustrated micromixer 1 is based on a base plate 2 having separate supply ports 1a and 1b for introducing a plurality of fluids, in this example two kinds of fluids A and B, into the apparatus. Here, for example, a base 10 is attached to the supply ports 1a and 1b, and supply pipes (not shown) of fluids A and B are connected to the base 10 to supply the fluids A and B to the respective supply ports. .

On the base plate 2, one or a plurality ( at least three or more) of fluids A and B for guiding the fluids A and B from the supply ports 1a and 1b are provided. The distribution plate 3 having the channel 30, that is, the distribution channel 30A through which the fluid A passes and the distribution channel 30B through which the fluid B passes similarly is placed. Here, the fluid from the supply ports 1a and 1b is led to the storage portion 11 formed in the distribution plate 3 through the supply holes 11a and 11b (see FIG. 4), as shown in FIG. To the two distribution channels 30A or 30B addressed to each fluid.

The distribution channel 30 includes a main channel 33 extending in parallel between adjacent distribution channels 30A and 30B, and a plurality of channels branched from the main channel 33 and extending toward the opposing main channel 33. The branch flow path 34 is provided. The main flow portion 33 extends substantially linearly from the storage portion 11 of the separated fluid A to the opposing storage portion 11 side of the fluid B, and adopts an arrangement in which a different kind of distribution channel enters between the two homogeneous distribution channels. As a result, the four distribution channels are arranged in such a manner that channels of different fluids are alternately arranged. At this time, the branch channel 34 has at least the tip 35 of the branch channel 34 of the adjacent one of the distribution channels 30 and at least the tip 35 of the branch channel 34 of the other distribution channel 30 extending from the main channel 33. Arranged alternately in the direction. In the illustrated example, the entire branch channel 34 of one adjacent distribution channel 30A and the entire branch channel 34 of the other distribution channel 30B are alternately arranged. Further, of the distribution channels 30, the central distribution channel 36, which is the distribution channel 30 sandwiched between the two distribution channels, is a branch channel for both of the two distribution channels 30 sandwiching it. In contrast, the outer distribution flow path 37 that is the outer distribution flow path 30 that is not sandwiched includes the branch flow path 34 only on the side facing the central distribution flow path 36. Although not shown, when there are two distribution channels 30 provided on the distribution plate, the two distribution channels 30 have branch channels 34 only on the sides facing each other.
Further, as shown in the example, the main flow path 33 and the branch flow path 34 of the distribution flow path 30 are linear, so that the fluid can be smoothly flowed compared to the case where the main flow path 33 and the branch flow path 34 are zigzag or wavy. The flow of the fluid can be advantageously achieved, and rapid mixing of the fluid can be advantageously achieved, and the area of the distribution channel 30 provided on the distribution plate 3 can be reduced to reduce the size of the micromixer 1. Can be planned. In the illustrated example, the branch flow path 34 extends in a direction orthogonal to the extension direction of the main flow path 33, but the extension direction of the branch flow path 34 with respect to the main flow path 33 may be in another angular range. it can. In the illustrated example, the distal end portion 35 of the branch channel 34 has a shape having a certain curvature, but may have other shapes such as corner portions.

  Further, as shown in FIGS. 3 and 6, on the distribution plate 3, it extends in a direction crossing all the branch channels 34 between the adjacent distribution channels 30 </ b> A, 30 </ b> B, and an intersection 41 with the branch channel 34. A merging plate 4 having a mixing channel 40 that guides the fluid from is placed. Each mixing channel 40 is a straight line orthogonal to all the branch channels 34 between the adjacent distribution channels 30A and 30B, and intersects each branch channel 34 between the adjacent distribution channels 30A and 30B at intersections 41, respectively. It will be. Then, the fluids A and B are alternately introduced into each mixing channel 40 in the longitudinal direction via the intersection points 41 with all the branch channels 34. That is, the fluids A and B are divided into minute sections via a large number of intersections 41 and supplied into each mixing channel 40, where each of the fluids A and B is a molecule between the minute fluid sections. Are mixed with each other between adjacent sections. Since this divided fluid section is very small, on the order of micrometers to nanometers, the diffusion distance of molecules is shortened and rapid mixing is performed. Also, by making the mixing channel 40 linear, the area of the portion where the mixing channel 40 is provided on the confluence plate 4 is smaller than when the mixing channel 40 is zigzag or corrugated. Therefore, when the main flow path 33 of the distribution flow path 30 is combined with a straight line, the micromixer 1 can be further downsized.

  According to such a mixing principle, the size of the fluid section can be controlled by adjusting the width and depth of the distribution channel 30 and the mixing channel 40 described above, and as a result, the mixing characteristics of the fluid can be controlled. Can be controlled. The mixing pattern of the fluid sections in the mixing channel 40 is, for example, when a combination of the distribution channel 30 and the mixing channel 40 as shown in FIG. When only the adjacent mixing channels 40A and 40B (see FIG. 7B) are extracted, and all of them are combined, the fluid guided at each intersection 41 is schematically shown for each fluid section. The mixed pattern is as follows. That is, a mixed pattern is formed in which a small fluid section of fluid guided at each intersection 41 is surrounded by different fluid sections. If such a fluid division mixing pattern is realized, fluid mixing will be accelerated.

  The above-described effective mixing of the fluids A and B is performed for each mixing flow path 40, and the mixed fluid after mixing is collected and temporarily stored in a storage portion 50 formed in the top plate 5 as shown in FIG. And is discharged from the outlet channel 51.

Further, there are three or more distribution channels 30, and the width W 1 of the main channel 33 of the central distribution channel 36, which is the distribution channel 30 sandwiched between two distribution channels among the distribution channels 30. Is larger than the width W2 of the main flow path 33 of the other distribution flow path 30, that is, the outer distribution flow path 37 that is the outer distribution flow path 30 that is not sandwiched .
The fluid is guided from the outer distribution channel 37 to the single mixing channel 40, while the fluid is guided from the central distribution channel 36 to the two mixing channels 40. Therefore, when all the widths of the main flow path 33 of the distribution flow path 30 are the same, the amount of fluid guided from the outer distribution flow path 37 to one mixing flow path 40 is one from the central distribution flow path 36. This is larger than the amount of fluid guided to the mixing flow path 40, and a large difference occurs in the fluid mixing ratio between the mixing flow paths. As a result, fluids cannot be rapidly mixed due to the difference in the mixing ratio.
As a countermeasure, by making the width W1 of the main flow path 33 of the central distribution flow path 36 larger than the width W2 of the main flow path 33 of the outer distribution flow path 37, the volume of the main flow path 33 of the central distribution flow path 36 is increased. The total volume of the fluid supplied to the central distribution channel 36 can be made larger than the total amount of the fluid supplied to the outer distribution channel 37 by making it larger than the volume of the main channel 33 of the outer distribution channel 37. . By doing so, the amount of fluid guided from the central distribution channel 36 per 401 mixing channels can be increased, so that the difference in the fluid mixing ratio between the mixing channels is reduced. As a result, rapid mixing is possible without suppressing rapid mixing of fluids as described above.
At this time, the width W1 of the main flow path 33 of the central distribution flow path 36 is preferably in the range of 120 to 300% of the width W2 of the main flow path 33 of the outer distribution flow path 37, more preferably 150 to 200%. It is in the range. When the width W1 of the main flow path 33 of the central distribution flow path 36 is less than 120% of the width W2 of the main flow path 33 of the outer distribution flow path 37, the width W1 of the main flow path 33 of the central distribution flow path 36 is reduced. Therefore, the volume of the main flow path 33 of the central distribution flow path 36 cannot be sufficiently secured, and the amount of fluid guided from the central distribution flow path 36 to the mixing flow path 40 cannot be effectively secured. . For this reason, the difference in the mixing ratio of the fluid between the mixing channels cannot be sufficiently reduced, and the fluid may not be rapidly mixed. On the other hand, when the width W1 of the main flow path 33 of the central distribution flow path 36 exceeds 300% of the width W2 of the main flow path 33 of the outer distribution flow path 37, the width W2 of the main flow path 33 of the central distribution flow path 36 is Since the volume of the main flow path 33 of the central distribution flow path 36 becomes excessively large, the volume of the fluid guided from the outer distribution flow path 37 to the mixing flow path 40 is mixed from the central distribution flow path 36 to the mixing flow path. The amount of fluid led to 40 becomes too large. As a result, a large difference occurs in the mixing ratio of the fluid between the mixing flow paths, and there is a possibility that the fluids cannot be rapidly mixed due to the difference in the mixing ratio.

  Furthermore, by using the laminated body of the base plate 2, the distribution plate 3, the merging plate 4 and the top plate 5 as one element and using a plurality of the elements stacked, the mixing is repeated a plurality of times to further improve the mixing efficiency. It is also possible to plan. Alternatively, it is possible to mix three or more fluids using the elements in parallel. Of course, it is possible to increase the number of fluids introduced in the element from two to three or more.

  The above description shows only a part of the embodiment of the present invention, and these configurations can be combined alternately or various changes can be made without departing from the gist of the present invention.

  Next, a micromixer according to the present invention (example micromixer) and a conventional micromixer (conventional example micromixer) were prototyped and their performance was evaluated for comparison, and will be described below.

  As shown in FIG. 3, the micromixer 1 is a main channel (length: 15.32 mm, width: 0.18 mm, depth: 5 mm) through which the fluid from the supply ports 1a and 1b of the base plate 2 passes. And the distribution plate 3 having four distribution channels 30A and 30B consisting of branch channels (length: 0.3 mm, width: 0.08 mm, depth: 5 mm), and all between adjacent distribution channels Merging plate 4 having three mixing channels 40 (each channel size: length 13.5 mm, width 0.1 mm, depth 3 mm) extending in a direction crossing the branch channel, and each distribution channel 40 And a top plate 5 having a reservoir 50 of the mixed fluid that has been merged and mixed at the top. The mixed fluid from the outlet channel 51 was configured so that the mixed aqueous solution directly flows into the ultraviolet-visible spectrophotometer.

  As shown in FIG. 12, the prior art micromixer 201 is provided with a first tubular member 202 and a second tubular member 203 facing each other, a first fluid 7 passing through the first tubular member 202, and a second tubular member. After the second fluid 8 passing through 203 is collided with the second fluid 8 to form a mixed fluid, the mixed fluid 9 is discharged through the third tubular member 206. Both the first tubular member 202 and the second tubular member 203 have a length of 35 mm, an outer diameter of 1.6 mm, and an inner diameter of 0.48 mm, and the third tubular member 206 has a length of 50 mm and an outer diameter of 1.6 mm. The inner diameter was 0.48 mm. Further, similarly to the example micromixer, the mixed fluid from the outlet channel was configured such that the mixed aqueous solution directly flowed into the UV-visible spectrophotometer.

Using these microphone mixers, the mixing characteristics of two types of fluids were evaluated. The two fluids mixed were KI: KIO ₃ : H ₃ BO ₃ : 2% sulfuric acid aqueous solution (fluid A), 1.60% KI aqueous solution, 0.41% KIO ₃ aqueous solution, 3.34% H ₃ BO ₃ aqueous solution and 0.80% NaOH aqueous solution are mixed at a ratio of 1: 1: 1: 1 by volume ratio, which is a four-type mixed aqueous solution (fluid B). These fluids were supplied at a flow rate of 0.5 to 7.5 mL / min from the respective supply ports of the example micromixer and the conventional micromixer. Then, the mixing characteristics of fluid A and fluid B were evaluated using the Villermuux / Dushman reaction. That is, when two types of fluids are mixed, a fast reaction is preferentially advanced when the mixing characteristics are good, and conversely, a slow reaction is also advanced when the mixing characteristics are poor. The mixing characteristics can be evaluated by measuring the concentration of the substance. Specifically, when mixing the fluids A and B, acid - alkali neutralization reaction or mixing characteristic reactions occur at a I ₂ formation reaction worse case, if this I ₂ formation reaction occurred, generating The I ₂ partly becomes I ₃ ⁻ , but this I ₃ ⁻ has an absorption peak at a wavelength of 353 nm, and thus its absorbance was measured to evaluate the mixing characteristics. In addition, it has shown that the mixing characteristic is excellent, so that the absorption peak in the wavelength of 353 nm is small.

  As a result, the example micromixer had a small absorption peak at a wavelength of 353 nm and excellent mixing characteristics at any flow rate compared with the conventional micromixer.

  ADVANTAGE OF THE INVENTION According to this invention, it became possible to provide the micromixer which can improve mixing efficiency markedly though it is small. Since mixing can be performed with such extremely high efficiency, the technique is advantageously adapted to fields such as μ-TAS, a microchemical plant, and a gradient mixer for high performance liquid chromatography.

It is a top view of the micromixer according to the present invention. It is a sectional side view of the micromixer shown in FIG. It is an exploded view of the micromixer shown in FIG. It is a top view of the base plate of the micromixer shown in FIG. It is a top view of the distribution plate of the micromixer shown in FIG. It is a top view of the confluence | merging plate of the micromixer shown in FIG. It is the schematic which shows the combination of a distribution flow path and a mixing flow path. It is a top view of the top plate of the micromixer shown in FIG. It is a conceptual diagram explaining a prior art micromixer.

Explanation of symbols

1 Micromixer A, B Fluid 1a, 1b Supply port 2 Base plate 10 Base 3 Distribution plate 30, 30A, 30B Distribution flow path 33 Main flow path 34 Branch flow path 35 Branch flow path tip 36 Central distribution flow path 37 Outer distribution flow path 11 Reservoir 40, 40A, 40B Mixed channel 4 Junction plate 41 Intersection 5 Top plate 50 Reservoir 51 Exit channel

Claims (6)

A base plate having a plurality of supply ports to which fluid is supplied, a distribution plate having at least two distribution channels in total, at least one for each fluid through which the fluid from each supply port passes, and a fluid from each distribution channel In a micromixer formed by stacking a merging plate having at least one mixing channel for merging and mixing, and a top plate having a reservoir for storing the mixed fluid,
The distribution channel includes a main channel extending in parallel between adjacent distribution channels, and a plurality of branch channels branched from the main channel and extending toward the opposing main channel, The branch channel is an arrangement in which at least the tip of the branch channel of one adjacent distribution channel and at least the tip of the branch channel of the other distribution channel are alternately arranged,
The micromixer characterized in that the mixing channel extends in a direction crossing all the branch channels between the adjacent distribution channels, and guides a fluid from an intersection with each branch channel.   The micromixer according to claim 1, wherein the main flow channel and the branch flow channel of the distribution flow channel extend linearly.   The micromixer according to claim 1, wherein the mixing channel extends linearly.   There are three or more distribution channels, and the width of the main channel of the distribution channel sandwiched between two distribution channels is the width of the main channel of the other distribution channels. The micromixer according to any one of claims 1 to 3, wherein the micromixer is larger.   The micromixer according to claim 4, wherein a width of the main flow path of the distribution flow path sandwiched between the distribution flow paths is in a range of 120 to 300% of a width of the main flow path of the other distribution flow paths.   The micromixer according to any one of claims 1 to 5, wherein a plurality of laminated bodies formed by laminating the base plate, distribution plate, confluence plate, and top plate are laminated.

Images