JP4326971B2 - Micromixer and manufacturing method thereof - Google Patents

Description

  The present invention relates to a micromixer provided with a fluid mixing mechanism and a manufacturing method thereof.

  In recent years, due to the application of semiconductor microfabrication technology, μ-TAS (μ-Total Analysis System) aimed at miniaturization of chemical analyzers, biochemical analyzers, etc. has attracted attention, gene analysis chips, chemical synthesis chips, biochemistry Application to synthetic chips, environmental analysis chips, etc. is expected. When these miniaturizations are realized, the benefits of reducing the amount of samples, reagents, waste liquid, etc., shortening measurement time, reducing power consumption of the entire system, reducing costs, and portability compared to conventional analyzers. A wide variety of research has been conducted because of expectations.

  One component of these analysis systems is a micromixer for mixing in a micro area. As this micromixer, a wide variety of micromixers such as a mixer using a porous filter and a multilayer mixer have been reported. One of them is a micromixer that performs mixing by chaotic mixing using a spiral flow of fluid.

  In a fine channel (microchannel), since the representative dimension and flow velocity of the channel are both small, the Reynolds number is often about 200 or less. When the Reynolds number is small, turbulence hardly occurs in the microchannel, and laminar flow becomes dominant. Therefore, the mixing of fluids is mainly diffusion mixing at the contact interface between fluids.

  In order to improve the diffusion efficiency, it is conceivable to increase the contact interface area between fluids. In this case, when chaotic mixing by spiral flow is used, the contact interface area between the fluids increases with the number of rotations of the fluid, and the layer thickness of the fluid decreases. Therefore, the mixing efficiency of the fluid is considered to increase exponentially with the progress of rotation.

  For example, Non-Patent Document 1 discloses a micromixer having a groove on one surface of a flow wall in a rectangular cross-section channel. Non-Patent Document 2 discloses a micromixer having grooves on two surfaces of a flow wall in a rectangular channel.

However, these micromixers are not suitable for miniaturization since the rotation efficiency is low and the flow path length required for mixing becomes large.
Chaotic Mixer for Microchannels (Science, Vol.295, p647-651 (2002)) BARRIER EMBEDDED CHAOTIC MICROMIXER (Proc.16th Int.Conf.MEMS03, Kyoto, Japan, 2003, p339-342)

  The present invention has been made in view of the above problems, and a main object of the present invention is to provide a micromixer capable of shortening the distance required for mixing and a method for manufacturing the micromixer.

In order to achieve the above object, the present invention provides a plurality of fluid inlets into which a fluid flows, a mixing channel having a substantially quadrangular cross section in which the fluid flowing in from the plurality of fluid inlets flows and is stirred, A fluid outlet from which the fluid flowing through the mixing channel flows out, and at least three of the four surfaces of the mixing channel are formed with irregularities, and the irregularities formed on the at least three surfaces are The micromixer is characterized in that the micromixer is arranged in a spiral shape with respect to the flow direction .

  In the present invention, since the concavo-convex portions are formed on at least three of the four surfaces having a substantially quadrangular cross section of the mixing channel, the mixing efficiency of the fluids is improved. As a result, since the length of the flow path can be shortened, the micromixer can be miniaturized.

In this case, it is preferable that the uneven portion is formed on four sides over the entire surface of the mixing channel. This is because the mixing efficiency is further improved.

In the present invention, a plurality of fluid inlets into which fluid flows, a mixing channel having a substantially quadrangular cross section in which the fluid flowing in from the plurality of fluid inlets flows and is stirred, and flows through the mixing channel. A fluid outlet from which the fluid flows out , and at least three of the four surfaces of the mixing channel are provided with irregularities, and the irregularities formed on the at least three surfaces are in the direction of fluid flow. A method of manufacturing a micromixer arranged in a spiral ,
Application process of applying a photosensitive resist on the first light-shielding layer of a transparent substrate provided with a first light-shielding layer having a pattern corresponding to the uneven portion on the side surface of the mixing channel on at least one surface When,
The photosensitive resist is exposed at a specific tilt angle by obliquely exposing the transparent substrate at a specific tilt angle from the surface side opposite to the surface on which the first light-shielding layer of the transparent substrate is formed, A first exposure step of exposing a portion corresponding to the uneven portion on the side surface of the mixing channel ;
A second exposure step of exposing a portion corresponding to the mixed flow path by exposing the surface of the photosensitive resist through a photomask;
A development step of developing the photosensitive resist to obtain a mold of the mixing channel portion;
And a mixing channel forming step of forming a mixing channel of the micromixer using the mold. A method of manufacturing a micromixer is provided.

  In the present invention, since the manufacturing method is as described above, it is possible to form an uneven portion on the side surface of the mixing channel, and it is possible to manufacture a micromixer with extremely good mixing efficiency. The mixing channel has a lid formed on the groove, and the side surface of the mixing channel here means a surface corresponding to the side of the groove.

  In this invention, the 2nd light shielding layer is formed in the surface on the opposite side to the surface in which the 1st light shielding layer of the said transparent substrate was formed, In the said 1st exposure process, via the said 2nd light shielding layer, It is preferable to perform oblique exposure. This is because the uneven portions on the side surfaces can be efficiently formed by performing oblique exposure in this way.

The present invention also includes a plurality of fluid inlets through which fluid flows, a mixing channel having a substantially quadrangular cross section in which the fluid flowing in from the plurality of fluid inlets flows and agitated, and the fluid flowing through the mixing channel. A fluid outlet from which the fluid flows out , and at least three of the four surfaces of the mixing channel are provided with irregularities, and the irregularities formed on the at least three surfaces are in the flow direction of the fluid, A method of manufacturing a micromixer arranged in a spiral ,
A groove forming step for forming a groove serving as the mixed flow path by etching through a resist pattern formed on the surface of the substrate;
A coating step of coating a photosensitive resist on the surface of the substrate where the groove is formed;
From the resist surface side, an exposure process in which the photosensitive resist is exposed at a specific tilt angle by oblique exposure at a specific tilt angle, and a portion corresponding to the concavo-convex portion on the side surface of the mixing channel is exposed, and
And a developing step for developing the photosensitive resist. A method for producing a micromixer is provided.

  Similarly, in the present invention, a micromixer with good mixing efficiency can be obtained, and at the same time, even when the substrate material is not suitable for a forming method using a mold, for example, on the side surface of the mixing channel. An uneven portion can be formed, and the range of material selection can be expanded.

  In the said invention, you may further have the 2nd etching process of etching from the said photosensitive resist after the said image development process, and the peeling process of peeling the said photosensitive resist. This has the advantage that the mixing channel can be formed from a single material.

  In the present invention, fluid rotation is caused by the plurality of grooves. Therefore, the mixing efficiency between fluids is improved. As a result, since the length of the flow path can be shortened, the micromixer can be downsized.

  Hereinafter, the micromixer of the present invention and the production method thereof will be described in detail.

A. Micromixer First, the micromixer of the present invention will be described.

  The micromixer of the present invention includes a plurality of fluid inlets into which fluid flows, a mixing channel having a substantially quadrangular cross section in which the fluid flowing in from the plurality of fluid inlets flows and is stirred, and flows through the mixing channel. And a fluid outlet through which the fluid flows out, and at least three of the four surfaces of the mixing channel are formed with uneven portions.

  The micromixer of the present invention will be described with reference to the drawings. FIG. 1 is a schematic plan view showing an example of the micromixer of the present invention. As shown in FIG. 1, the micromixer 10 of the present invention is a microchannel structure having a plurality of fluid inlets 11, a mixing channel 12, and a fluid outlet 13. The fluid flowing in from the plurality of fluid inlets 11 is mixed in the mixing channel 12 and flows out from the fluid outlet 13.

  The micromixer of the present invention is not limited to the form shown in FIG. 1 and is not particularly limited as long as it has a form normally used as a micromixer.

  Next, the internal structure of the mixing channel 12 will be described. FIG. 2 is a schematic perspective view showing the internal structure of the mixing channel 12 of FIG. As shown in FIG. 2, the inside of the mixing channel 12 includes a channel 14 having a substantially quadrilateral cross section. A plurality of concave and convex portions 15 are provided on the bottom surface and both side surfaces of the flow path 14. In addition, although the cover part is provided and the flow path 14 is formed so that the groove part of FIG. 2 may be sealed, it abbreviate | omits about a cover part in this figure.

  The plurality of concavo-convex portions 15 are inclined in the fluid flow direction from the upper surface side to the bottom surface side of the flow channel 14 on one side surface of the flow channel 14, and from the one side surface side of the flow channel 14 to the other side surface on the bottom surface of the flow channel 14. The other side surface of the flow channel 14 is inclined in the fluid flow direction from the bottom surface side to the upper surface side of the flow channel 14. In this case, although not shown in the drawing, it is preferable that a similar uneven portion is formed on the lid portion.

  In this case, the fluid flowing in from the plurality of fluid inflow paths 11 flows through the flow path 14 while drawing a spiral along the plurality of uneven portions 15. If the number of rotations for drawing a helix increases, the contact interface area between the fluids increases, and the layer thickness of each fluid decreases. Therefore, the mixing efficiency between fluids is improved. As a result, since the length of the mixing channel 12 can be shortened, it is possible to reduce the size of the micromixer. In this case, it is preferable that the same uneven portion is also formed in the lid portion, which can further improve the mixing efficiency.

  For example, the height of the groove portion of the flow path 14 is about 1 μm to 250 μm, and the width is about 1 μm to 250 μm. Moreover, the depth of the groove of the uneven portion 15 is about 1 μm to 100 μm, the width is about 1 μm to 100 μm, and the interval between the grooves is about 1 μm to 100 μm.

  It should be noted that the plurality of grooves or protrusions formed in the concavo-convex portion 15 need only be inclined, and may not be horizontal or perpendicular to the fluid flow direction. In this example, the fluid flows while drawing a spiral, but the present invention is not limited to this. For example, the adjacent concavo-convex portions 15 do not have to be inclined in the same direction, and may be inclined in directions opposite to each other. Even in this case, since the rotation of the fluid occurs, the fluids are mixed efficiently.

  Moreover, in order to exhibit the effect of this invention, the uneven | corrugated | grooved part 15 should just be provided in any 3 surfaces among the 4 surfaces of the flow path 14. FIG. Therefore, the uneven portion 15 may be provided on the lid portion of the flow channel 14 instead of the bottom surface of the flow channel 14. Moreover, you may provide the uneven | corrugated | grooved part 15 in the bottom face, cover part, and one side surface of the flow path 14 as another shape. Further, the uneven portions 15 may be provided on all four surfaces of the flow path 14. In this case, the rotation of the fluid is efficiently generated by the concavo-convex portions 15 provided on the entire surface of the four surfaces in the flow path 14.

  Moreover, the uneven | corrugated | grooved part 15 should just be provided in at least one part of each surface. That is, although the uneven part 15 may be formed on one surface of the flow path 14, for example, the entire side surface, the uneven part 15 may be formed on a part thereof. Further, a group of concave and convex portions 15 having grooves or convex portions arranged in a plurality of units may be provided at predetermined intervals with respect to the fluid flow direction. Accordingly, there may be a portion where the uneven portion 15 is not partially provided in the fluid flow direction. This is because even if the uneven portion 15 is partially provided in this way, fluid rotation occurs in the flow path 14.

B. Next, the 1st manufacturing method of the micromixer of this invention is demonstrated.

The method of manufacturing a micromixer according to the present invention includes a plurality of fluid inlets into which fluid flows, a mixing channel having a substantially quadrangular cross section in which the fluid flowing in from the plurality of fluid inlets flows and is stirred, and the mixed flow A fluid outlet from which the fluid flowing through a channel flows out, and a method of manufacturing a micromixer in which an uneven portion is formed on a side surface of the mixing channel,
Application process of applying a photosensitive resist on the first light-shielding layer of a transparent substrate provided with a first light-shielding layer provided with a pattern corresponding to the concavo-convex portion on the side surface of the mixing channel on at least one surface And exposing the photosensitive resist at a specific inclination angle by obliquely exposing the transparent substrate at a specific inclination angle from the surface side opposite to the surface of the transparent substrate on which the first light shielding layer is formed. A first exposure step for exposing a portion corresponding to the concavo-convex portion, and a second exposure step for exposing the portion corresponding to the mixed flow path by exposing the surface of the photosensitive resist through a photomask. And developing the photosensitive resist to obtain a mold of the mixing channel portion, and a mixing channel forming step of forming a mixing channel of a micromixer using the mold. The one in which the features.

  Such a method for producing a micromixer of the present invention will be described with reference to the drawings.

1. Manufacturing Process of Micromixer Mold First, the manufacturing process of the micromixer mold will be described. FIG. 3 is a process diagram showing an example of a method for producing a micromixer mold.

(Patterning process)
First, both surfaces of the glass substrate 20 as a transparent substrate are washed (FIG. 3A). The dimensions of the glass substrate 20 are, for example, 2 cm wide × 3 cm long × 1 mm thick. Next, Cr is vapor-deposited on both surfaces of the glass substrate 20 to form a Cr layer 21 as the first light-shielding layer on the front surface side and a Cr layer 22 as the second light-shielding layer on the back surface side (FIG. 3B). The film thickness of the Cr layers 21 and 22 is, for example, 2000 mm. Next, the Cr layers 21 and 22 are patterned (FIG. 3C).

  Here, as shown in FIG. 4A, the patterned Cr layer 21 has slit portions 21a and 21b in which a plurality of holes are arranged in a line. The slit portions 21a and 21b are formed in parallel with each other. As shown in FIG. 4B, the patterned Cr layer 22 is formed with one-letter shaped exposure control holes 22a and 22b. The exposure control holes 22a and 22b are formed so as to be arranged in parallel to each other. Light incident from the exposure control holes 22a and 22b passes through the slit portions 21a and 21b. Details of the positional relationship between the slit portions 21a and 21b and the exposure control holes 22a and 22b will be described later.

  In this example, Cr layers are formed as both the first light shielding layer and the second light shielding layer on both surfaces of the glass substrate 20 as the transparent substrate. However, in the present invention, at least the surface side, that is, the first light shielding layer. Should just be formed. For example, in the first exposure step described later, the second light-shielding layer is not particularly required when exposing from the back side through a photomask.

(Coating process)
Next, a photosensitive resist, that is, a photosensitive resin (for example, a thick film photosensitive resin manufactured by SU-8 MicroChem) is applied to the surface side of the glass substrate 20 to form a photosensitive resin film 23 (FIG. 3 ( d)).

(First exposure step)
Next, the glass substrate 20 is tilted and exposed from the Cr layer 22 side (FIG. 3E). Next, after returning the glass substrate 20 to a horizontal position, the glass substrate 20 is inclined to the opposite side and exposed from the Cr layer 22 side (FIG. 3F). Thereby, the convex part of the side surface of the photosensitive resin film 23 after development shown in FIG. 3J is exposed (cured in this case).

  Here, details of the light incident from the exposure control holes 22a and 22b in FIG. 4B passing through the slit portions 21a and 21b in FIG. 4A and passing through the photosensitive resin film 23 will be described. As shown in FIG. 5, the light incident from the exposure control hole 22 a is refracted by the difference in refractive index between air, the glass substrate 20 and the photosensitive resin film 23. Thereby, the positional relationship between the exposure control holes 22a and 22b and the slit portions 21a and 21b is determined.

When the opening width of the exposure control hole 22a is w1, the opening width of the slit portion 21a is w2, the shift distance of the incident light within the glass substrate 20 is d, and the interval between the slit portions 21a is q, the following The relationship of Formula (1) and Formula (2) is required. The relationship between the exposure control hole 22b and the slit portion 21b is the same.
w1 ≧ w2 (1)
q ≧ 2d (2)

  The relationship of the formula (1) is necessary for incident light to enter all of the plurality of holes of the slit portion 21a, and the relationship of the formula (2) is the exposure control when the glass substrate 20 is inclined reversely. This is necessary so that light incident from the hole 22a does not pass through the slit portion 21a.

  Under the above conditions, light can pass through the slit portions 21a and 21b only once in two exposures. Thereby, desired exposure can be realized without covering the Cr layer 22 with another mask. Therefore, the manufacturing process of the micromixer can be shortened.

  In addition, when it has a light-shielding part only in the surface side of the glass substrate 20, ie, when it has only a 1st light-shielding part, when making light inject from the slit part 21a of Fig.4 (a), the slit part 21b is masked. When the light is incident from the slit portion 21b, the convex portion on the side surface of the photosensitive resin film 23 can be exposed (cured in this case) by masking the slit portion 21a.

(Second exposure step)
Next, the photomask 24 is covered from the surface side of the photosensitive resin film 23 and exposed from the surface side (FIG. 3G). Thereby, the rectangular parallelepiped portion of the photosensitive resin film 23 after development shown in FIG. 3 (j), that is, the portion corresponding to the groove portion of the obtained mixing channel is exposed (cured in this case).

(Development process)
Next, a photosensitive resin is further applied on the photosensitive resin film 23 to form a photosensitive resin film 25 (FIG. 3H). Next, a photomask 26 different from the photomask 24 of FIG. 3G is covered from the surface side of the photosensitive resin film 25 and exposed from the surface side (FIG. 3I). Thereby, the convex portion on the surface side of the photosensitive resin film 23 after development shown in FIG. 3 (j), that is, the concave and convex portion formed on the bottom surface of the groove portion of the obtained mixing channel is exposed (hardened in this case). Finally, by performing development, a mold 27 (hereinafter, sometimes referred to as a micromixer mold) of the mixing channel of the micromixer is formed (FIG. 3 (j)). IPA (Isopropyl alcohol) is used for drying.

  In this example, an uneven portion is formed on the bottom surface of the groove portion of the mixing channel obtained in this way, but the present invention is not particularly limited to this, and the uneven surface is formed on the bottom surface as described above. It may not have a step of forming a part. In that case, you may make it form an uneven | corrugated | grooved part in the cover part 31 of FIG. 6 mentioned later. Thereby, the three surfaces of the flow path 14 in FIG. 2 have grooves.

2. Process for producing micromixer from micromixer mold (mixing flow path forming process)
Next, a process for producing a micromixer from the micromixer mold will be described. FIG. 6 is a process diagram showing an example of a process for producing a micromixer from a micromixer mold. First, PVA (Polyvinyl alcohol) is applied to the surface of both ends of the micromixer mold 27 of FIG. 6A to form a PVA application part 28 (FIG. 6B), and a brass channel inlet / outlet fitting 29 (with an inner diameter of about 1 mm) is attached to both PVA application portions 28 (FIG. 6C). As a result, the space between the micromixer mold 27 and the channel inlet / outlet fitting 29 is sealed.

(Transfer process)
Next, the micromixer mold 27 is inserted into the mold, and a thermosetting silicone resin such as PDMS (Polydimethylsiloxane: silicone rubber (Sylgard184 manufactured by Dow Corning)) mixed at a ratio of the main agent to the hardener of 10: 1 is poured. Bake for 90 minutes at 85 ° C. after degassing under reduced pressure. Thereby, the silicone resin becomes the silicone resin structure 30 to which the pattern of the micromixer mold 27 is transferred (FIG. 6D).
In this example, a thermosetting silicone resin is used, but a photocurable resin may be used. A material having elasticity after curing is more preferable.

  Next, the PVA application part 28 is removed using pure water (FIG. 6E). Next, the micromixer mold 27 is removed (FIG. 6F). Next, the silicone resin structure 30 is adsorbed on a lid portion 31 such as glass or an acrylic plate to complete the micromixer of the present invention (FIG. 6G). Since the silicone resin has a self-adsorption property, if the adsorption surface of the silicone resin structure 30 is flat, the silicone resin structure is adsorbed to the lid portion 31. Thereby, it is not necessary to adhere the lid portion 31 to the silicone resin structure 30 in particular.

  Next, a method for manufacturing the lid part 31 will be described. FIG. 7 is a process diagram illustrating an example of a manufacturing process of a mold for making the lid portion 31. First, both surfaces of the glass substrate 40 are cleaned (FIG. 7A). Next, a photosensitive resist, that is, a photosensitive resin (for example, a thick film photosensitive resin manufactured by SU-8 MicroChem) is applied to the surface side of the glass substrate 40 to form a photosensitive resin film 41 (FIG. 7 ( b)).

  Next, the photomask 42 is covered from the surface side of the photosensitive resin film 41 and exposed from the surface side (FIG. 7C). Thereby, the uneven part formed in the upper surface of the groove part of the mixing channel obtained is exposed (hardened in this case). Next, by performing development, the mold 43 of the lid portion of the mixing channel of the micromixer is formed (FIG. 7D).

  Next, the mold 43 is fitted into the mold, and a thermosetting silicone resin 44 such as PDMS (Polydimethylsiloxane: silicone rubber (Sylgard184 manufactured by Dow Corning)) in which the ratio of the main agent and the hardener is mixed at 10: 1 is poured. Bake after degassing under reduced pressure. Thereby, the silicone resin 44 becomes the lid portion 31 to which the pattern of the mold 43 has been transferred (FIG. 7F).

  In this example, a thermosetting silicone resin is used, but a photocurable resin may be used. A material having elasticity after curing is more preferable. Further, a silicon substrate can be used instead of the glass substrate 40. In that case, it can be set as the shape of the cover part 31 by performing an etching process.

3. Step of Sealing Micromixer Next, the step of sealing the silicone resin structure 30 in FIG. FIG. 8 is a schematic diagram illustrating a method for sealing the silicone resin structure 30. In the micromixer 10 of FIG. 6 (g), when the fluid pressure in the micromixer 10 is larger than the adsorption force of the silicone resin, the silicone resin structure 30 is peeled off from the lid portion 31, and liquid leakage occurs.

  Therefore, in order to withstand a certain amount of fluid pressure, in the present invention, the silicone resin structure 30 is adsorbed to a lid portion 31 such as a slide glass and then sandwiched between acrylic plates 32 and bolts (not shown) and nuts (not shown). (Not shown) and fixed. With this sealing method, for example, it was confirmed that no liquid leakage occurred even when the flow rate of water was 200 ml / min. Further, for example, the silicone resin structure 30 and the lid portion 31 may be bonded and sealed.

  In addition, when making the fluid in the micromixer 10 flow by suction, it is not necessary to consider the adsorption | suction power of the above silicone resins.

C. Second Manufacturing Method of Micromixer A second manufacturing method of the micromixer according to the present invention includes a plurality of fluid inlets into which fluid flows, and a cross-sectional view in which the fluid flowing in from the plurality of fluid inlets flows and is stirred. A method of manufacturing a micromixer having a quadrilateral mixing channel and a fluid outlet through which the fluid flowing through the mixing channel flows out, and having a concavo-convex portion formed on a side surface of the mixing channel,
Etching through a resist pattern formed on the surface of the substrate to form a groove that forms the mixed flow path, and a photosensitive resist is applied to the surface of the substrate on which the groove is formed A coating step, an exposure step of exposing the photosensitive resist at a specific inclination angle by exposing the photosensitive resist at a specific inclination angle from the resist surface side, and exposing the portion corresponding to the uneven portion; And a developing step for developing the photosensitive resist.

(1) 1st embodiment The 2nd manufacturing method of the micromixer of this invention is demonstrated using drawing. FIG. 9 is a process diagram showing an example of a second manufacturing method of the micromixer.

(Groove formation process)
First, as a substrate, both surfaces of the silicon substrate 50 are cleaned (FIG. 9A). Next, a resist 51 is applied on the surface side of the silicon substrate 50 and patterned (FIG. 9B). As the resist 51, for example, a positive resist OFPR (manufactured by Tokyo Ohka Kogyo Co., Ltd.) or the like can be used. Next, an etching process is performed from the surface side of the silicon substrate 50 (FIG. 9C). Thereby, as shown in FIG. 10A, the uneven portion 15 on the bottom surface of the flow path 14 shown in FIG. 2 is formed. Next, the resist 51 is peeled from the silicon substrate 50 (FIG. 9D).

In addition, the above process does not have an essential process, and the uneven | corrugated | grooved part 15 does not need to be formed here. In that case, if the uneven part is formed in the lid part, the three surfaces of the flow path 14 have the uneven part.
Here, the material of the substrate is not particularly limited as long as it is a material that can be etched, but it is preferable to use silicon or the like shown in this example.

(Etching process)
Next, a resist 52 is applied to the surface side of the silicon substrate 50 (FIG. 9E). The resist 52 can be formed using the same material as the resist 51. Thereafter, the resist 52 is patterned (FIG. 9F).

  Next, an etching process is performed from the surface side of the silicon substrate 50 (FIG. 9G). Thereby, the flow path 14 is formed as shown in FIG. Next, the resist 52 is removed from the silicon substrate 50 (FIG. 9H).

(Coating process)
Next, a photosensitive resin (SU-8 100 100 μm MicroChem thick film photosensitive resin or the like) is applied on the surface of the silicon substrate 50 to form a photosensitive resin film 53 (FIG. 9I).

(Patterning process and exposure process)
Next, the photomask 54 composed of the glass substrate and the Cr layers 21 and 22 shown in FIG. 3D is placed so that the Cr layer 22 is on the surface side (FIG. 9J), and FIGS. Exposure is performed twice by the method shown in FIG. 3 (f) (FIG. 9 (k)).

(Development process)
Next, after removing the photomask 54, the photosensitive resin film 53 is developed (FIG. 9L). Thereby, as shown in FIG.10 (c), the several uneven | corrugated | grooved part 15 is formed in the side surface of the flow path 14. As shown in FIG. In addition, as a developing solution used for the developing process, a developing solution (manufactured by Tokyo Ohka Kogyo Co., Ltd.) or the like can be used. Next, the micromixer is completed by sealing the lid.

(2) Second Embodiment Next, a second embodiment of the second manufacturing method of the micromixer of the present invention will be described with reference to the drawings. FIG. 11 is a process diagram showing a second embodiment of the second manufacturing method of the micromixer.

(Groove formation process and etching process)
First, both surfaces of the silicon substrate 60 are cleaned (FIG. 11A). Next, a resist 61 is applied to the surface side of the silicon substrate 60 and patterned (FIG. 11B). As the resist 62, for example, a positive resist OFPR (manufactured by Tokyo Ohka Kogyo Co., Ltd.) or the like can be used. Next, an etching process is performed from the surface side of the silicon substrate 60 (FIG. 11C). Thereby, the flow path 14 shown in FIG. 2 is formed. Next, the resist 61 is peeled from the silicon substrate 60 (FIG. 11D).
In addition, the material similar to what was described in the said 1st embodiment can be used for the material of the board | substrate used for a 2nd embodiment.

(Coating process)
Next, a photosensitive electrodeposition resist is applied to the surface side of the silicon substrate 60 to form an electrodeposition resist film 62 (FIG. 11E).

(Patterning process and exposure process)
Next, a photomask 63 composed of the glass substrate and Cr layers 21 and 22 shown in FIG. 3D is placed so that the Cr layer 22 is on the surface side (FIG. 11F), and FIGS. Exposure is performed twice by the method shown in FIG. 3 (f) (FIG. 11 (g)).
Next, the photomask 63 is removed, and a photomask 64 having the same shape as the photomask 26 shown in FIG. 3I is covered and exposed (FIG. 11H).

(Development process)
Next, development processing is performed to remove the exposed portion. Thereby, the silicon substrate 60 of the part which forms the groove | channel of the uneven | corrugated | grooved part of the side surface and bottom face of a flow path is exposed.
(Second etching process)
Next, by performing an etching process on the surface side of the silicon substrate 60, the exposed portion of the silicon substrate 60 is eroded and a plurality of grooves in the concavo-convex portion 15 are formed (FIG. 11 (i)).

(Peeling process)
Next, the micro-mixer is completed by peeling the electrodeposition resist film 62 and then attaching the lid portion in close contact.

The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.
For example, each of the first embodiment and the second embodiment includes a step of forming an uneven portion at the bottom of the groove portion of the mixing channel, but the present invention is not limited to this, and the uneven portion is formed at the bottom. What does not have the process of forming a part is also contained in this invention. In this case, it is preferable that an uneven portion is formed on the lid. This is because uneven portions are formed on the three surfaces of the mixing channel, and the mixing efficiency of the obtained micromixer can be improved.

Hereinafter, the present invention will be specifically described using examples and comparative examples.
(Examples 1 and 2)
In Examples 1 and 2, a micromixer was manufactured by the first manufacturing method of the micromixer of the present invention. 12 (a) and 12 (b) are schematic views showing micromixer molds 27a and 27b when the micromixers of Examples 1 and 2 are produced, respectively.

  As shown in FIG. 12A, a plurality of convex portions 27aa are provided at equal intervals on the entire top surface of the micromixer mold 27a. A group of convex portions 27ab arranged at equal intervals in units of 10 is provided on one side surface of the micromixer mold 27a at regular intervals, and the convex portions 27ac arranged at equal intervals in units of 10 are provided on the other side surface of the micromixer mold 27a. A group was provided at regular intervals. The group of convex portions 27ab and the group of convex portions 27ac were alternately provided in the fluid flow direction. Accordingly, grooves are provided on the two surfaces of the flow path with respect to the fluid flow direction.

  As shown in FIG. 12B, a plurality of convex portions 27ba were provided at equal intervals on the entire top surface of the micromixer mold 27b. A group of convex portions 27bb arranged at equal intervals in units of 10 is provided on one side surface of the micromixer mold 27b at regular intervals, and the convex portions 27bc arranged at equal intervals in units of 10 are provided on the other side surface of the micromixer mold 27b. A group was provided at regular intervals. The group of convex portions 27bb and the group of convex portions 27bc were provided so as to overlap with the fluid flow direction. Therefore, with respect to the flow direction of the fluid, there are alternately portions where grooves are provided on three surfaces of the flow channel and portions where grooves are provided on one surface of the flow channel.

  The rectangular parallelepiped parts of the micromixer molds 27a and 27b are made of a thick film negative photoresist (SU-8 100 100 μm MicroChem thick film photosensitive resin), and the convex parts of the micromixer molds 27a and 27b are thick film negative photoresists. (SU-8 50 30 μm MicroChem thick film photosensitive resin) was used. PDMS (Polydimethylsiloxane: Silicone rubber (Sylgard184 manufactured by Dow Corning)) was used as the silicone resin for transferring the micromixer molds 27a and 27b. Table 1 shows other conditions when the micromixers of Examples 1 and 2 were manufactured.

(Comparative Example 1)
In Comparative Example 1, a micromixer was produced using a micromixer mold that was not provided with convex portions. FIG. 12C is a schematic view showing a micromixer mold 27 c when the micromixer of Comparative Example 1 is manufactured. As shown in FIG. 12C, no convex portion was provided on each surface of the micromixer mold 27c. Therefore, no groove is formed in the flow path of the micromixer of Comparative Example 1. Other manufacturing conditions are the same as those in Examples 1 and 2.

(Comparative Example 2)
In Comparative Example 2, a convex portion was provided only on the upper surface. A micromixer was prepared using a micromixer mold. FIG. 12D is a schematic diagram showing a micromixer mold 27d when the micromixer of Comparative Example 2 is manufactured. As shown in FIG. 12D, a plurality of convex portions 27da are provided at equal intervals on the entire upper surface of the micromixer mold 27d. Therefore, a groove is formed only on the bottom surface of the flow path of the micromixer of Comparative Example 2.

(Evaluation)
Cyan and yellow aqueous pigments were poured into the micromixers of Examples 1 and 2 and Comparative Examples 1 and 2, and fluid mixing and rotation were examined. Each aqueous pigment was prepared by dissolving 3 g of pigment in 6 ml of solution. A microsyringe pump was used to inject these aqueous pigments, and a fluid having a flow rate of 5 μl / min was introduced into each of the fluid inflow channels 11 so that the total fluid flow rate flowing through the flow channel 14 was 10 μl / min. . This flow rate is about 1.7 cm / s when converted into the average flow rate from the flow path dimensions of the micromixer. In this case, the Reynolds number is about 1.7 × 10 ⁻³ (where the channel representative dimension (channel width) l is 100 μm, the fluid kinematic coefficient ν is the kinematic viscosity coefficient of water (20 ° C .: 10 0.06 cm ² / s)).

  Table 2 shows the rotation rates of the fluids flowing through the flow paths 14 of Examples 1 and 2 and Comparative Examples 1 and 2. Here, the rotation rate represents the number of rotations of the fluid with respect to the distance (about 1.4 cm) from the start points of the plurality of grooves 15 to the fluid outlet 13. As shown in Table 2, the micromixer of Example 2 had the highest rotation rate, followed by Example 1, followed by the micromixer of Comparative Example 2, and the rotation rate of the micromixer of Comparative Example 1 was 0.

  The rotation rate of the micromixer of Example 2 was lower than the rotation rate of the micromixer of Example 1. This is because the groove 15 is always provided on any two surfaces of the flow path 14 of the micromixer of the first embodiment, whereas the flow path 14 of the micromixer of the second embodiment has a groove 15 only on the bottom surface. This is thought to be due to the presence of the formed part.

  Furthermore, in order to confirm the influence of the flow rate of the fluid on the rotation rate, a similar experiment was attempted with the flow rate being doubled to 20 μl / min, but there was no difference in the rotation rate.

  From the above, it can be seen that a three-dimensional array having inclined grooves on the side surfaces of the flow path 14 is more effective for mixing fluid than a two-dimensional array having inclined grooves only on the bottom surface of the flow path 14. .

It is a schematic plan view which shows an example of the micromixer of this invention. It is a schematic perspective view which shows the internal structure of a mixing channel. It is process drawing which shows an example of the manufacturing method of a micro mixer mold. It is a schematic plan view explaining the exposure control hole and slit part of a Cr layer. It is the schematic explaining the positional relationship of an exposure control hole and a slit part. It is process drawing which shows an example of the process of manufacturing a micromixer from a micromixer mold. It is process drawing which shows an example of the manufacturing process of a cover part. It is the schematic explaining the sealing method of a silicone resin structure. It is process drawing which shows the 1st aspect of the 2nd manufacturing method of a micro mixer. It is a schematic plan view of a silicon substrate. It is process drawing which shows the 2nd aspect of the 2nd manufacturing method of a micro mixer. It is a schematic perspective view which shows the micromixer casting_mold | template used when producing the micromixer of an Example and a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Micromixer 14 ... Channel 15 ... Uneven part 20 ... Glass substrate 21, 22 ... Cr layer 21a, 21b ... Slit part 22a, 22b ... Exposure control hole 23 ... Photosensitive resin film 27 ... Micromixer mold 30 ... Silicone resin Structure

Claims (6)

A plurality of fluid inlets through which fluid flows;
A mixing channel having a substantially quadrangular cross section in which the fluid flowing in from the plurality of fluid inlets flows and is stirred;
A fluid outlet through which the fluid flowing through the mixing channel flows out;
An uneven portion is formed on at least three of the four surfaces of the mixing channel, and the uneven portion formed on the at least three surfaces is arranged in a spiral shape with respect to the fluid flow direction. Micromixer to do. 2. The micromixer according to claim 1, wherein the uneven portions are formed on the entire four surfaces of the mixing channel. A plurality of fluid inlets into which fluid flows, a mixing channel having a substantially quadrangular cross section in which the fluid flowing in from the plurality of fluid inlets flows and agitated, and a fluid from which the fluid flowing through the mixing channel flows out An uneven portion is formed on at least three of the four surfaces of the mixing channel, and the uneven portion formed on the at least three surfaces is arranged in a spiral shape with respect to the fluid flow direction. A method of manufacturing a micromixer,
Application process of applying a photosensitive resist on the first light-shielding layer of a transparent substrate provided with a first light-shielding layer provided with a pattern corresponding to the concavo-convex portion on the side surface of the mixing channel on at least one surface When,
The photosensitive resist is exposed at a specific tilt angle by obliquely exposing the transparent substrate at a specific tilt angle from the surface side opposite to the surface on which the first light-shielding layer of the transparent substrate is formed, A first exposure step of exposing a portion corresponding to the uneven portion on the side surface of the mixing channel ;
A second exposure step of exposing a portion corresponding to the mixed flow path by exposing the surface of the photosensitive resist through a photomask;
A development step of developing the photosensitive resist to obtain a mold of the mixing channel portion;
And a mixing channel forming step of forming a mixing channel of the micromixer by using the mold.   A second light-shielding layer is formed on the surface of the transparent substrate opposite to the surface on which the first light-shielding layer is formed, and in the first exposure step, oblique exposure is performed via the second light-shielding layer. The manufacturing method of the micromixer of Claim 3 characterized by the above-mentioned. A plurality of fluid inlets into which fluid flows, a mixing channel having a substantially quadrangular cross section in which the fluid flowing in from the plurality of fluid inlets flows and agitated, and a fluid from which the fluid flowing through the mixing channel flows out An uneven portion is formed on at least three of the four surfaces of the mixing channel, and the uneven portion formed on the at least three surfaces is arranged in a spiral shape with respect to the fluid flow direction. A method of manufacturing a micromixer,
A groove forming step for forming a groove serving as the mixed flow path by etching through a resist pattern formed on the surface of the substrate;
A coating step of coating a photosensitive resist on the surface of the substrate where the groove is formed;
From the resist surface side, an exposure process in which the photosensitive resist is exposed at a specific tilt angle by oblique exposure at a specific tilt angle, and a portion corresponding to the concavo-convex portion on the side surface of the mixing channel is exposed, and
And a developing process for developing the photosensitive resist. A second etching step of etching from the photosensitive resist after the developing step;
The method for producing a micromixer according to claim 5, further comprising: a peeling step of peeling the photosensitive resist.

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