JP5832282B2 - Micro mixer - Google Patents

Description

  The present invention relates to a micromixer in which problems due to a structure in which a plurality of members are combined are eliminated.

  In recent years, a technique for forming a minute flow path on the order of nanometers to micrometers on a glass or resin chip and realizing analysis in the chemical or bio field in the flow path has attracted attention in recent years. Such a technique is called μTAS (micro total analysis system) or Lab-on-a-chip. In this technology, in order to realize various analyzes on a minute chip, development of each elemental technology such as liquid feeding, mixing, and detection on the chip is in progress.

  When performing analysis and reaction operation using fluid on such a small chip, efficient stirring of the fluid and mixing of a plurality of fluids are necessary to achieve high-precision and rapid analysis. is important. Generally, there are a laminar flow state and a turbulent flow state as a state in which the liquid flows. In a micro space such as a minute reaction channel on the order of nanometers to micrometers, a laminar flow state is affected by the viscous force of the fluid (see, for example, Patent Document 1). In turbulent mixing, the fluid is continuously divided into thin layers by the rotational motion of the fluid mass, and the mixing proceeds as small fragments. However, in laminar mixing, division by fluid motion is impossible, so split- There is only mixing by the method of forcibly mixing (for example, refer nonpatent literature 1).

  As a method of dividing a two-component fluid into a number of streams and mixing them, a micromixer as shown in Patent Document 2 has been reported. The micromixer includes a plurality of flow paths through which fluid flows, a distribution flow path that is connected to each of the flow paths and distributes the fluid, and a mixing unit that mixes the distributed fluids. A conventional micromixer is configured by laminating a plurality of plates such as a plate in which a supply port and a channel are formed, a plate in which a distribution channel is formed, and a plate in which a mixing unit is formed.

  Conventionally, a micromixer is manufactured by using a LIGA (Lithographie Galvanoformung Abformung) process that directly forms a fine structure on the surface of a PMMA (acrylic resin) plate using light having a very short wavelength emitted from a synchrotron. ing. In this process, since exposure is performed with a directional short-wavelength light called synchrotron light, a special and expensive exposure apparatus is required, and there is a problem that industrial mass production is difficult. Further, since the processing is performed using photolithography technology, there is a problem that only a structure obtained by simply extending a plan view in the vertical direction can be realized, and there is a design limitation.

  In addition, since the material of the mixing part is a metal such as Ni formed by plating, there is a problem that the mixed state cannot be confirmed visually without optical transparency. Furthermore, since the material of the mixing part is a conductor, there is a problem of heat generation or electric shock due to energization of the conductor of the mixing part when a fluid is moved by applying a potential difference. In addition, since the mixing unit cannot be embedded in the analysis chip and must be externally mounted on the chip, there is a problem that miniaturization is difficult.

  In addition, the micromixer sometimes causes the entire micromixer to have a high temperature in order to promote fluid flow and mixing. When used in this way, the material of the analysis chip (glass) and the material of the mixing part are different, so there is a difference in the amount of contraction when the heat is applied (difference in thermal expansion coefficient), and reliability due to thermal stress There was a problem of deterioration and leakage at the connection. In the case of the conventional laminated type, there is a possibility that delamination occurs at the joint interface between the two, and problems such as liquid leakage may occur.

Further, the conventional micromixer has a plurality of members laminated, and an adhesive may be used to join the members together. However, the components of the adhesive may be dissolved in the fluid, and impurities may be mixed into the obtained mixed solution.
As described above, the conventional micromixer has been pointed out to have a defect due to a structure in which a plurality of members are combined.

JP 2010-188305 A JP 2009-233561 A

Junichi Yoshida, Development and application of microreactors, CMC Publishing Co., Ltd.

  The present invention has been devised in view of such a conventional situation, and solves problems caused by a structure in which a plurality of members are combined, such as interfacial peeling due to deformation and mixing of adhesive components, and is reliable. An object of the present invention is to provide a micromixer with high height.

The micromixer according to claim 1 of the present invention includes a first channel through which a first fluid flows, a second channel through which a second fluid flows, and a plurality of branches branched from the first channel. A first branch channel, a plurality of second branch channels branched from the second channel, the first fluid branched in the first branch channel, and a branch in the second branch channel And a mixing unit that combines and mixes the second fluid that has been mixed, and includes the first flow channel, the second flow channel, the first branch flow channel, and the second branch flow channel. And the mixing section is provided inside a single substrate, and the mixing section is formed hollow in the single substrate .
The micromixer according to a second aspect of the present invention is the micromixer according to the first aspect, wherein the first flow channel, the second flow channel, the first branch flow channel, and the second branch flow channel are respectively It is characterized by being formed hollow in a single substrate.
According to a third aspect of the present invention, the micromixer according to the first or second aspect is characterized in that the substrate is made of a transparent material.
A micromixer according to a fourth aspect of the present invention is the micromixer according to any one of the first to third aspects, wherein the first branch channel and the second branch channel are alternately arranged in the width direction. It is characterized by that.

In the micromixer of the present invention, the first channel, the second channel, the first branch channel, the second branch channel, and the mixing unit are provided inside a single substrate. Therefore, there is no bonding interface like a conventional micromixer. Therefore, there are no problems caused by the structure in which a plurality of members are combined, such as interfacial peeling due to deformation and mixing of adhesive components. As a result, the present invention can provide a highly reliable micromixer.
In the method of manufacturing a micromixer according to the present invention, the base is the first channel, the second channel, the first branch channel, the second branch channel, and the mixing unit. Forming a modified portion in the substrate by irradiating the region with laser light, removing the modified portion by etching, and forming the first flow path, the second flow path, Forming the first branch channel, the second branch channel, and the mixing section, so that the first channel, the second channel, the first branch channel, A micromixer in which the second branch channel and the mixing part are provided inside a single substrate can be manufactured. Further, in the present invention, since modification and etching by laser light irradiation are used, it is possible to form an arbitrary structure three-dimensionally, and it is possible to easily form the optimally shaped flow path, branch flow path, and mixing section. Can be formed. As a result, the present invention can provide a method of manufacturing a micromixer that can manufacture a highly reliable micromixer by a simple method.

The perspective view which shows typically one Embodiment of the micromixer of this invention. The top view which shows a 1st branch channel and a 2nd branch channel in the micromixer shown in FIG. The top view which shows a 1st branch channel and a 2nd branch channel in the micromixer shown in FIG. In micromixer shown in FIG. 1 _{is a} longitudinal sectional view of the Y 1 -Y ₂ line. In micromixer shown in FIG. 1 _{is a} longitudinal sectional view of the X 1 -X ₂ line. The perspective view which shows typically the example of 1 structure of the analysis chip carrying the micro mixer of this invention. Sectional drawing which shows the manufacturing method of the micromixer of this invention in order of a process.

  Hereinafter, an embodiment of a micromixer and a manufacturing method thereof according to the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view schematically showing an embodiment of the micromixer of the present invention.
The micromixer 1 includes a first flow path 3a through which a first fluid A flows, a second flow path 3b through which a second fluid B flows through the first flow path 3a, A plurality of first branch channels 4a branched from the first channel 3a, a plurality of second branch channels 4b branched from the second channel 3b, and the first branch channel 4a were shunted. A mixing section 5 for combining the first fluid A and the second fluid B divided in the second branch flow path 4b and mixing; and a third flow path 6 extending from the mixing section 5; And at least.

In the micromixer 1 of the present invention, the first channel 3a, the second channel 3b, the first branch channel 4a, the second branch channel 4b, and the mixing unit 5 are a single unit. It is provided inside the base 2.
In the present invention, the first channel 3 a, the second channel 3 b, the first branch channel 4 a, the second branch channel 4 b, and the mixing unit 5 are provided inside the single substrate 2. Therefore, there is no joint interface as in the conventional micromixer 1. Therefore, there are no problems caused by the structure in which a plurality of members are combined, such as interfacial peeling due to deformation and mixing of adhesive components. As a result, the micromixer 1 of the present invention solves problems caused by a structure in which a plurality of members are combined, and has high reliability.

The substrate 2 is preferably made of a transparent material. An example of the transparent material constituting the substrate 2 is glass. Since the base 2 is made of a transparent material (having optical transparency), the mixed state can be confirmed visually or with an optical microscope. Since the mixing unit 5 can be observed from the outside, for example, it is possible to observe whether or not the channel is blocked by foreign matter or bubbles in the fluid in the mixing unit 5.
Furthermore, when the base body 2 is made of an insulator such as glass, there is no concern about heat generation or electric shock due to energization of the mixing unit 5 when an electric potential is applied to the fluid for movement. Further, by forming the base 2 from glass, it is possible to maintain mechanical strength even when the flow path and the mixing unit 5 have a fine structure.

Although the width | variety and depth of the 1st flow path 3a, the 2nd flow path 3b, and the 3rd flow path 6 are not specifically limited, For example, it can be set to 1-500 micrometers. Each flow path does not need to have the same dimensions, and is arbitrarily determined. For example, the liquid can be flowed smoothly by adjusting the width of each flow path according to the viscosity of the liquid.
As will be described later, any of these channels can be formed by, for example, modifying glass using laser light and etching the modified portion. Thereby, the cross-sectional shape of the flow path can be arbitrarily controlled. For example, it can be round or hexagonal.

FIG. 2 is a plan view of the first branch channel 4a and the second branch channel 4b as viewed from the mixing unit 5 side.
The first branch channel 4a is composed of a plurality of tributaries 4a1, 4a2, 4a3,. The second branch channel 4b is composed of a plurality of tributaries 4b1, 4b2, 4b3,. .. And tributaries 4b1, 4b2, 4b3,... Are alternately arranged in the width direction of the tributaries. That is, 4a1, 4b1, 4a2, 4b2, 4a3, 4b3,. The first branch channel 4a and the second branch channel 4b may each have a comb-teeth shape as shown in FIG. 2 (a), or may each have a saw-tooth shape as shown in FIG. 2 (b). . These are only examples, and the tip of the diversion channel can be formed into an R shape, the comb-teeth rectangle can be formed into a polygon, or the saw-tooth can be provided with a projection.

  In this way, the first branch channel 4a and the second branch channel 4b are alternately spaced apart from each other and arranged at equal intervals, and the first fluid A and the second branch channel 5 are connected to each branch channel. Fluid B is mixed. Since the pressure difference of the pump (see the following figure) acts to flow the fluid in the flow path, the fluid in the flow path can flow at any speed, and the mixing speed is controlled Can do.

FIG. 3 is a plan view of the first branch channel 4a and the second branch channel 4b as viewed from the mixing unit 5 side. FIG. 3 shows an example in which the first branch channel 4a and the second branch channel 4b are alternately arranged in an array as viewed from the mixing unit 5 side.
As will be described later, these branch channels can be formed by, for example, modifying glass using laser light and etching the modified portion. Thereby, a complicated three-dimensional structure as shown in the figure can be formed in the glass substrate 2. As shown in FIG. 3 (a), it is possible to make the diversion channel into a quadrangular shape, and the first diversion channel 4a and the second diversion channel 4b can be alternately arranged in a lattice pattern, as shown in FIG. 3 (b). As shown, the shunt channel may be round and the first shunt channel 4a and the second shunt channel 4b may be arranged alternately. Further, as shown in FIG. 3C, a honeycomb structure is obtained by arranging hexagonal diversion channels and alternately arranging the first diversion channels 4a and the second diversion channels 4b. This shape is preferable from the viewpoint of the mechanical strength of the flow channel itself and the density of the flow channel.

4 is a longitudinal sectional view taken along line Y ₁ -Y ₂ in the micromixer shown in FIG.
As shown in FIG. 4, if the flow paths are formed in a plurality of tree shapes (comb teeth are formed when the trunk portion is viewed from the plane direction), the branch flow paths can be arranged in an array. In the example shown in FIG. 4, the dimensions of the part corresponding to the trunk of the branch channel, the part corresponding to the branch, and the part corresponding to the leaf are different, but the dimension of the channel can be arbitrarily formed by the mixing speed and the pressure applied to the fluid.

  The width and depth of the first branch channel 4a and the second branch channel 4b are not particularly limited, but can be set to, for example, 0.1 to 50 μm. Although the space | interval between branch flow paths is not specifically limited, For example, it can be set as 1-100 micrometers. The number of branches in the branch channel is not particularly limited, but can be 10 to 3000, for example. Although the width | variety and depth of the mixing part 5 are not specifically limited, For example, it can be set as 1-500 micrometers.

These branch channels can be formed by, for example, modifying glass using laser light and etching the modified portion. Thereby, the cross-sectional shape of a flow path and a shunt flow path can be controlled arbitrarily.
FIG. 5 is a longitudinal sectional view taken along line X1-X2 in the micromixer shown in FIG. For example, the cross-sectional shape of the flow path or the branch flow path can be a quadrangular shape as shown in FIG. 5A, or a semicircular shape as shown in FIG. Moreover, it can also be made into the trapezoid shape as shown in FIG.5 (c). These are only examples, and may be a polygon such as a hexagon, for example, and only need to have a contact point with the mixing unit 5. From the viewpoint of mixing efficiency, a shape that has a large contact area with the mixing unit 5, a high density of the parallel branch channels, and a mechanical strength of the branch channels themselves is desirable.

  As shown in FIG. 5, the mixing part 5 is formed hollow in the substrate 2 such as glass. The position of the micromixer 1 in the base 2 can be formed to an arbitrary depth as long as it is within the thickness of the base 2. If the upper surface of the mixing unit 5 is deeper than the glass surface, the surface of the base 2 functions as a lid for the mixing unit 5, so there is no need to provide a separate lid, and the micromixer 1 is completely embedded in the base 2. A structure without connection points can be achieved.

FIG. 6 is a perspective view schematically showing a configuration example of an analysis chip on which the micromixer 1 of the present invention as described above is mounted.
The analysis chip 10 includes a micromixer 1 provided integrally with the base of the analysis chip. The analysis chip 10 includes a carrier inlet 11, a sample inlet 12, a micromixer 1, a reactor 13, a detection unit 14, a pump 15, and an outlet 16. However, this is an example of the configuration of the analysis chip, and the present invention is not limited thereto. Is not to be done. For example, it may be configured to have other necessary functions such as a filter, a separator, and an electronic circuit. Moreover, each component is not limited to one, For example, it can also be set as the structure provided with multiple sample inlets and reactors.

Next, a method for manufacturing such a micromixer 1 will be described.
FIG. 7 is a cross-sectional view showing the method of manufacturing the micromixer of the present invention in the order of steps.
The manufacturing method of the micromixer 1 of the present invention is such that the base 2 has the first flow path 3 a, the second flow path 3 b, the first branch flow path 4 a, the second branch flow path 4 b, and the mixing section 5. A step of forming a modified portion 20 in the substrate 2 by irradiating the substrate 2 with a laser beam, and removing the modified portion by etching, so that a first channel 3a and a second channel 3b are formed in the substrate 2. And a step of forming the first branch channel 4a, the second branch channel 4b, and the mixing unit 5.

(1) In the substrate 2, the first flow path 3 a, the second flow path 3 b, the first branch flow path 4 a, the second branch flow path 4 b, and the region to be the mixing unit 5 are irradiated with laser light. A reforming portion 20 is formed inside the base 2.
First, the first channel 3a, the second channel 3b, the first branch channel 4a, the second branch channel 4b, and the region to be the mixing unit 5 of the substrate 2 are modified by laser beam irradiation. .

  As an example of the method, as shown in FIG. 7A, a method of forming a modified portion 20 in which the material of the substrate 2 is modified in the substrate 2 by irradiating the substrate 2 with a laser beam L. Can be mentioned. The reforming unit 20 is provided in a region that becomes the first channel 3 a, the second channel 3 b, the first branch channel 4 a, the second branch channel 4 b, and the mixing unit 5.

  The laser beam L is irradiated, for example, from one main surface 2a side of the base 2 and forms a focal point S at a desired position in the base 2. At the position where the focal point S is connected, the material of the substrate 2 is modified. Therefore, the position of the focal point S is sequentially shifted and moved (scanned) while irradiating the laser light L, and the first flow path 3a, the second flow path 3b, the first branch path 4a, and the second branch path. The reforming part 20 can be formed by connecting the focal point S to 4b and the entire region to be the mixing part 5.

  Examples of the light source of the laser light L include femtosecond laser light. By irradiating the laser beam L, for example, a modified portion having a diameter of several μm to several tens of μm can be obtained. Further, the modified portion 20 having a desired shape can be formed by controlling the position where the focal point S of the laser beam L is connected inside the base 2.

  When forming the modified portion 20, the laser beam L may be irradiated only from one or the other main surface of the substrate 2, or from both main surfaces of the substrate 2. The laser beam L may be irradiated.

(2) The modified portion 20 is removed by etching, and the first flow path 3a, the second flow path 3b, the first branch flow path 4a, the second branch flow path 4b, and the mixing section 5 are removed from the base 2 by etching. Form.
Next, the reforming part 20 formed in the previous process is removed, and the first flow path 3a, the second flow path 3b, the first branch path 4a, the second branch path 4b, and the mixing are formed in the base 2. Part 5 is formed.

  As an example of the method, as shown in FIG. 7B, the substrate 2 on which the modified portion 20 is formed is immersed in an etching solution (chemical solution) 30 and the modified portion 20 is etched (wet etching). The method of removing from the base | substrate 2 is mentioned. As a result, the first channel 3a, the second channel 3b, the first branch channel 4a, the second branch channel 4b, and the mixing unit 5 are formed in the base 2 in the portion where the reforming unit 21 exists. (See FIG. 7C).

  In the present embodiment, a quartz glass plate is used as the material of the substrate 2, and a solution mainly containing hydrofluoric acid (HF) is used as the etching solution 30. This etching utilizes the phenomenon that the modified portion 20 is etched much faster than the unmodified portion of the substrate 2, and as a result, the first flow path according to the shape of the modified portion. 3a, the second channel 3b, the first branch channel 4a, the second branch channel 4b, and the mixing unit 5 can be formed.

  The etching solution 30 is not particularly limited, and for example, a solution containing hydrofluoric acid (HF) as a main component, or a hydrofluoric acid-based mixed acid obtained by adding an appropriate amount of nitric acid or the like to hydrofluoric acid can be used. Also, other chemicals can be used depending on the material of the substrate 2.

The mixing unit 5 has a larger volume than the flow channel and the branch channel, and is far from the supply source of the etching solution (the inlets 11 and 12 and the outlet 16 of the analysis chip 10 shown in FIG. 6). It may take time to etch the portion. Therefore, as shown in FIG. 7B, an intrusion hole 21 for the etching solution 30 may be provided in the glass substrate 2 on the mixing unit 5. Accordingly, the processing speed of the etching is improved even in the mixing unit 5 which is larger in volume than the flow path and is far from the supply source of the etching solution 30 (the inlets 11 and 12 and the outlet 16 of the analysis chip 10 shown in FIG. 6). Can be made.
Even if the intrusion hole 21 has a minute diameter of 1 to 100 μm, the effect of improving the etching rate after modification can be sufficiently obtained. Further, the number of intrusion holes 21 is not limited to one, and a plurality of intrusion holes 21 may be formed.

  As shown in FIG. 7C, liquid leakage from the mixing portion 5 can be prevented by closing the intrusion hole 21 with a member 22 made of glass, metal, Teflon (registered trademark) or the like after completion of etching. Examples of the means for closing the intrusion hole 21 include filling of a metal paste or resin by a printing method, bonding of glass via an adhesive resin, anodic bonding of glass, and application of Teflon (registered trademark) tape.

  As described above, in the present invention, the modified portion 20 is formed inside the substrate 2 by irradiating the substrate 2 with laser light, and the modified portion 20 is removed by etching. The micromixer 1 in which the flow path 3b, the first branch path 4a, the second branch path 4b, and the mixing unit 5 are provided inside the single substrate 2 can be manufactured. As a result, in the method of manufacturing the micromixer 1 of the present invention, the highly reliable micromixer 1 can be manufactured by a simple method.

  In particular, in the present invention, since modification by laser light irradiation and etching after modification are used, a three-dimensional fine flow path from several tens of nanometers to several hundreds of micron repels can be collectively formed by adjusting the output of the laser light. It can be formed. In addition, since it is formed by direct drawing, a special and expensive exposure apparatus using a short wavelength such as synchrotron light or X-ray is unnecessary, and industrial mass production is possible. In addition, for laser beam drawing, it is possible to form an arbitrary structure three-dimensionally, with a high degree of freedom in design, and it is possible to form more optimal flow paths, branch flow paths, and mixing sections. Become.

  Further, since the flow path is formed by modification by laser light irradiation and etching, the mixing unit 5 can be embedded in the analysis chip, and the analysis chip itself can be easily downsized. In addition, since the material of the analysis chip and the material of the mixing part are the same, there is no difference in the amount of contraction when the heat is applied (difference in thermal expansion coefficient), so the reliability is high. Moreover, since the flow path, the diversion flow path, and the mixing part in the analysis chip are integrated and continuous, there is no concern of leakage at the connection part.

  The micromixer and the manufacturing method thereof according to the present invention have been described above. However, the present invention is not limited to the above-described example, and can be appropriately changed without departing from the spirit of the invention.

  The present invention is widely applicable to micromixers. In particular, it has an advantage in a numbering-up process in which mixing processing is performed in parallel using a large number (several hundreds to tens of thousands) of micromixers with the same structure.

  DESCRIPTION OF SYMBOLS 1 Micromixer, 2 base | substrate, 3a 1st flow path, 3b 2nd flow path, 4a 1st shunt flow path, 4b 2nd shunt flow path, 5 mixing part, 6 3rd flow path, A 1st Fluid, B Second fluid.

Claims (4)

A first flow path through which the first fluid flows;
A second flow path through which the second fluid flows;
A plurality of first branch channels branched from the first channel;
A plurality of second branch channels branched from the second channel;
A mixing unit that joins and mixes the first fluid diverted in the first diversion channel and the second fluid diverted in the second diversion channel; and
The first channel, the second channel, the first branch channel, the second branch channel, and the mixing unit are provided inside a single substrate, and the mixing unit is A micromixer characterized by being formed hollow in the single substrate . The first channel, the second channel, the first branch channel, and the second branch channel are each formed hollow in the single substrate. The micromixer according to claim 1. Micromixer according to claim 1 or 2 wherein the substrate is to consist of a transparent material, characterized by. The micromixer according to any one of claims 1 to 3, wherein the first branch channel and the second branch channel are alternately arranged in the width direction.

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