JP5660596B2 - Microfluidic device - Google Patents

Description

  The present invention relates to a microfluidic device, and more particularly to a microfluidic device suitable for a chemical reaction or extraction using an interface between two kinds of liquids.

  A microfluidic device is a device that performs chemical reaction, heat exchange, extraction, and the like while flowing a fluid through a microchannel having a width or depth of 1 mm or less. For example, when a microfluidic device is used for a chemical reaction, there is an advantage such as easy control of reaction conditions compared to a batch-type macro reactor, so that a high-purity compound can be synthesized efficiently. Are known. In particular, a microfluidic device having a microchannel having a width and a depth of 1 mm or less tends to form a laminar flow when two fluids are flowed through the microchannel. For example, an interface between the two fluids is used. It is suitable for chemical reactions (for example, organic synthesis utilizing chemical reactions at the interface, decomposition of compounds, etc.) and extraction (for example, moving components contained in one fluid to the other fluid through the interface).

On the other hand, for example, a microfluidic device having a microchannel having a width and a depth of 1 mm or less has a problem that the volume per unit time is small since the volume is smaller than that of a normal device. Yes.
In order to solve the problem, a technique using a flow path having a large width to height ratio (aspect ratio) has been developed. Specifically, for example, Patent Document 1 includes a flow path formed of a substantially rectangular microspace whose cross-sectional shape in the flow direction has a short side and a long side, and an inlet for injecting a raw material fluid into the reaction flow path. A microreactor provided in a slit shape on the long-side reaction channel wall surface is disclosed.

JP 2007-50320 A

When a microchannel having a large width-to-height ratio as described above is applied to processing using an interface (that is, chemical reaction or extraction), a wide interface is formed to improve processing efficiency. Is required. That is, in order to efficiently perform the process using the interface, it is desirable to form an interface parallel to the long side, not parallel to the short side of the cross section perpendicular to the fluid flow direction in the microchannel.
However, when two fluids having low compatibility are used, a force (surface tension) for reducing the interface acts, so it is difficult to keep the interface between the two fluids wide in the microchannel. Specifically, for example, even if two fluids are introduced into the microchannel so that an interface parallel to the long side is formed, the interface rotates in the middle of the channel and becomes an interface parallel to the short side. Or, the flow may be disturbed and a continuous interface may not be formed.

  Therefore, the present invention has a large amount of processing per time in one microfluidic device, and the interface between the first fluid and the second fluid in the main channel extends from the upstream end to the downstream end of the main channel. The main object is to provide a microfluidic device that can be easily formed uniformly in the width direction of the main channel.

In order to achieve the above object, the following invention is provided.
The invention according to claim 1
A main flow path in which the first fluid and the second fluid flow in contact with each other, and in the main flow path depth direction, which is a direction perpendicular to the main flow direction in which the first fluid and the second fluid flow in the main flow path. The length of the main flow path width direction which is a direction perpendicular to the main flow path depth direction in the cross section perpendicular to the main flow direction in the main flow path is composed of the first flow path and the second flow path arranged in parallel. A main flow path larger than the length in the direction of the path depth;
A first introduction path that communicates with the upstream end of the first flow path in the main flow direction and introduces the first fluid into the first flow path in the same direction as the main flow direction; The length in the same direction as the width direction of the main channel in the cross section perpendicular to the first introduction direction from the upstream side to the downstream side in the first introduction direction, which is the direction in which the first fluid flows in one introduction path. A first introduction path that gradually increases and has a region in which the length in the direction perpendicular to the main flow path width direction gradually decreases;
The second fluid is communicated with an end on the upstream side in the main flow direction in the second flow path, and the second fluid is placed in the same direction with respect to the main flow direction or at an acute angle with respect to the main flow direction from the direction side of the main flow path depth. A second introduction path to be introduced into the second flow path, wherein the second fluid flows in the second introduction path from the upstream side in the second introduction direction toward the downstream side in the second introduction direction. A second introduction path having a region in which the length in the same direction as the main channel width direction in the vertical cross section gradually increases and the length in the direction perpendicular to the main channel width direction gradually decreases;
A discharge path that communicates with an end of the main flow path downstream in the main flow direction and discharges the first fluid and the second fluid from the main flow path in the same direction with respect to the main flow direction; The length in the same direction as the width direction of the main channel in the cross section perpendicular to the discharge direction is gradually reduced from the upstream side to the downstream side in the discharge direction in which the first fluid and the second fluid flow. And a discharge channel having a region in which the length in the direction perpendicular to the width direction of the main channel gradually increases.

The invention according to claim 2
The microfluidic device according to claim 1, wherein a hydrophilic layer is formed on an inner surface of one of the first channel and the second channel, and a hydrophobic layer is formed on the other inner surface.

The invention according to claim 3
Of the first channel and the second channel, the surface along the main channel width direction in the channel in which the hydrophilic layer is formed, and the channel in the channel in which the hydrophobic layer and the hydrophobic layer are formed. 3. The microfluidic device according to claim 2, wherein at least one of the surface along the width direction of the main flow path has optical transparency, and the hydrophilic layer is a titanium dioxide layer.

The invention according to claim 4
4. The device according to claim 1, wherein at least one of the first flow path and the second flow path includes a plurality of grooves formed along the main flow direction and arranged in parallel with the main flow path width direction. 5. The microfluidic device according to claim 1.

  According to the present invention, the amount of processing per time in one microfluidic device is large, and the interface between the first fluid and the second fluid in the main channel is from the upstream end to the downstream end of the main channel. It is possible to achieve both the fact that it can be easily formed uniformly in the main channel width direction.

It is a perspective view which shows the outline of the flow path in the microfluidic device which concerns on 1st Embodiment of this invention. (A) The top view of the microfluidic device which concerns on 1st Embodiment, and (B) 2B-2B end elevations. FIG. 3 is a 3-3 end view in FIG. It is the schematic diagram which showed the confluence | merging part in another example of the microfluidic device which concerns on this invention. It is the perspective view which expanded the bottom face of the 2nd flow path in the confluence | merging part of the microfluidic device which concerns on 1st Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and repeated description is omitted as appropriate.

(First embodiment)
FIG. 1 is a perspective view showing an outline of the entire flow path in the microfluidic device according to the first embodiment. FIG. 2A is a plan view of the microfluidic device according to the first embodiment. FIG. 2B is an end view of 2B-2B in FIG. FIG. 3 is a 3-3 end view in FIG. 2B and 3 also show an example of a state in which two fluids are flowed through the microfluidic device of the first embodiment.

  As shown in FIGS. 1 and 2, the microfluidic device 100 according to the first embodiment includes a first introduction path 40 and a second introduction path that are communicated with a main flow path 10 and a junction 16 that is one end of the main flow path 10. The passage 50 is configured to include a discharge passage 60 communicated with the communication portion 18 that is the other end of the main flow passage 10.

  When using the microfluidic device 100 of the present embodiment, the first fluid 70 that is one of the two fluids is supplied to the first introduction port that is the end opposite to the joining portion 16 in the first introduction path 40. 42 is introduced into the first introduction path 40. In addition, the second fluid 80, which is the other of the two fluids, is introduced into the second introduction path 50 from the second introduction port 52, which is the end of the second introduction path 50 opposite to the joining portion 16. Then, the first fluid 70 flows in the first introduction path 40 from the first introduction port 42 to the joining portion 16 in the direction of arrow A, and the second fluid 80 passes through the second introduction passage 50 from the second introduction port 52 to the joining portion. By flowing up to 16 in the direction of arrow B, the first fluid 70 and the second fluid 80 merge at the junction 16. The first fluid 70 and the second fluid 80 that have joined at the joining portion 16 flow from the joining portion 16 to the communicating portion 18 in the main flow path 10, and are end portions opposite to the communicating portion 18 in the discharge path 60 from the communicating portion 18. It flows in the direction of arrow D to the discharge port 62 and is discharged from the microfluidic device 100 through the discharge port 62.

  In the present embodiment, for example, the shape of the cross section of the main channel perpendicular to the main flow direction, which is the direction in which the first fluid 70 and the second fluid 80 flow, is constant from the junction 16 to the communication unit 18. . In the main channel cross section, the channel width in the main channel width direction (arrow E direction) is 3 cm, for example, and the channel depth in the main channel depth direction (arrow F direction) perpendicular to the main channel width direction is For example, it is 200 μm. That is, the main channel 10 is a wide micro channel whose channel width is larger than the channel depth.

The first introduction path 40 is communicated with one cross section 16A divided by a merge line 16C parallel to the main flow path width direction in the main flow path cross section in the merge section 16, and the second introduction is introduced into the other cross section 16B. The road 50 is connected. That is, of the first introduction path cross section perpendicular to the first introduction direction (arrow A direction) in which the first fluid 70 flows in the first introduction path 40, the first introduction path cross section at the junction 16 is the above-described cross section. It is the same shape as 16A. Similarly, of the second introduction path cross section perpendicular to the second introduction direction (arrow B direction) in which the second fluid 80 flows in the second introduction path 50, the second introduction path cross section at the junction 16 is It has the same shape as the cross section 16B.
The flow path width of the cross section 16A and the flow path width of the cross section 16B are both the same as the flow path width of the main flow path 10. When the flow path depth of the cross section 16A and the flow path depth of the cross section 16B are totaled, the main flow path 10 It becomes the flow path depth. In the present embodiment, for example, the channel depth of the cross section 16A and the channel depth of the cross section 16B are both 100 μm.

Further, in the communication part 18, the discharge path 60 is communicated with the entire main channel cross section of the main channel 10 in the communication part 18. That is, of the discharge path cross section perpendicular to the discharge direction (arrow D direction) in which the first fluid 70 and the second fluid 80 flow in the discharge path 60, the discharge path cross section in the communication portion 18 is the same in the communication portion 18. The main channel 10 has the same shape as the main channel cross section.
Hereinafter, the main flow path 10, the first introduction path 40, the second introduction path 50, and the discharge path 60 will be described.

<Main channel>
First, the main channel 10 will be described.
The state of the flow of the first fluid 70 and the second fluid 80 in the main flow path 10 varies depending on characteristics such as the viscosity of the first fluid 70 and the second fluid 80 and conditions such as the flow velocity. However, in the microfluidic device 100 of the present embodiment, as will be described later, the first fluid 70 and the second fluid 80 are likely to flow in a laminar flow, and the interface between the first fluid 70 and the second fluid 80 is used as the main channel. 10 is easy to form in a direction perpendicular to the main channel depth direction.

In the present embodiment, for example, the interface between the first fluid 70 and the second fluid 80 is perpendicular to the main channel depth direction in the main channel 10 and passes through the merge line 16C (hereinafter, “ It is ideally formed at the boundary surface 25 ”, and the purpose is to form an interface between the first fluid 70 and the second fluid 80 at the boundary surface 25.
Hereinafter, description will be made on the assumption that the interface between the first fluid 70 and the second fluid 80 is formed on a target most ideal surface (that is, the boundary surface 25).

  The main flow path 10 includes a first flow path 20 having the cross section 16A as a cross section perpendicular to the main flow direction in the merging portion 16 (hereinafter may be referred to as a “first flow path cross section”), and a main flow direction in the merging section 16. The second flow path 30 having the cross section 16B as a cross section perpendicular to the cross section (hereinafter sometimes referred to as a “second flow path cross section”). The first flow path 20 and the second flow path 30 are the main flow path depths. It is configured in parallel in the vertical direction. That is, of the two flow paths divided at the boundary surface 25 of the main flow path 10, the flow path having the cross section 16A is the first flow path 20, and the flow path having the cross section 16B is the second flow path 30. It is.

In the present embodiment, for example, the shape of the first flow path cross section is constant from the merging portion 16 to the communication portion 18, and the shape of the second flow path cross section is constant from the merging portion 16 to the communication portion 18. That is, in the present embodiment, for example, the main flow path 10 is divided into the first flow path 20 and the second flow path 30 at the boundary surface 25 parallel to the main flow direction and the main flow path width direction. Both the channel depth and the channel depth of the second channel 30 are 100 μm from the junction 16 to the communication unit 18.
However, the boundary surface 25 is an imaginary surface, and no wall that separates the first flow path 20 and the second flow path 30 is provided inside the main flow path 10, and thus the first fluid 70 and the second fluid 80. Flows from the merging portion 16 to the communicating portion 18 while in contact with each other.

  In the present embodiment, as shown in FIGS. 2 and 3, for example, the first fluid 70 and the second fluid 80 flowing in the main flow path 10 form an interface on the boundary surface 25 and flow in a laminar flow. Yes. That is, for example, only the first fluid 70 flows in the first flow path 20, and only the second fluid 80 flows in the second flow path 30.

  The first channel cross section of the first channel 20 is, for example, one large rectangle as shown in FIG. For example, a hydrophilic layer 22 is formed on the inner surface of the first channel 20 other than the surface in contact with the second channel 30, and the thickness of the hydrophilic layer 22 is, for example, 0.2 μm.

On the other hand, as shown in FIGS. 2 and 3, the second flow path 30 is composed of, for example, a plurality of grooves 32 formed along the main flow direction and arranged in parallel in the main flow path width direction (for example, at regular intervals). Has been. That is, in the second flow path 30, for example, a plurality of partition plates 34 that separate the grooves 32 from each other are arranged in parallel in the main flow path width direction (for example, at regular intervals), so that the main flow path width direction in the second flow path 30. The second flow path 30 is divided by the partition plate 34. FIG. 2B is an end view of a surface passing through the groove 32.
In the present embodiment, for example, a hydrophobic layer 38 is formed on the inner surface of the groove 32 other than the surface in contact with the first flow path 20 and the surface 36 of the partition plate 34 in the main flow path width direction. ing.

  The flow path depth in the main flow path depth direction in the groove cross section that is a cross section of the groove 32 perpendicular to the main flow direction is the same as the flow path depth in the main flow path depth direction in the second flow path cross section. Then, for example, it is 100 μm. In this embodiment, for example, in all the grooves 32, the shape of the groove cross section is square, and the flow path width in the main flow path width direction in the groove cross section is 100 μm. In the present embodiment, for example, in all the partition plates 34, the interval between the grooves 32 (that is, the width of the partition plate 34 in the main channel width direction) is 100 μm, and the partition plate 34 has the main channel width direction in the main channel width direction. The surface 36 is in contact with the first flow path 20.

  In the present embodiment, for example, a titanium dioxide layer is used as the hydrophilic layer 22, and the channel lid 24 is a member in contact with the hydrophilic layer 22 formed on the surface along the main channel width direction of the first channel 20. A glass member is used. For example, the flow path lid 24 has light permeability, and the light irradiated from the flow path lid 24 outside the microfluidic device 100 reaches the hydrophilic layer 22 (that is, the main flow path width of the first flow path 20). The surface along the direction is light transmissive). Thereby, titanium dioxide in the hydrophilic layer 22 irradiated with light becomes hydrophilic (superhydrophilic) and acts as a photocatalyst for the first fluid 70 in contact with the hydrophilic layer 22.

<First introduction path and second introduction path>
Next, the first introduction path 40 and the second introduction path 50 will be described.
As shown in FIG. 2, the first introduction path 40 communicates with a cross section 16A in the main flow path 10 (that is, a cross section 16A in the first flow path 20), and the second introduction path 50 has a cross section 16B in the main flow path 10 (that is, a cross section 16B). The second channel 30 communicates with a cross section 16B).
The first fluid 70 is introduced from the first introduction path 40 to the first flow path 20 in the same direction as the main flow path direction, and the second fluid 80 is introduced from the second introduction path 50 to the second flow path 30, for example. It is introduced with an angle of 15 degrees in the main channel depth direction with respect to the main channel direction. That is, for example, the angle of the merging angle θ formed by the first introduction path 40 and the second introduction path 50 in the merging portion 16 is 15 degrees.

  For example, as shown in FIG. 2, the first introduction path 40 includes a first introduction port 42, a first rectifying region 44, and a first buffer region 46. In the first introduction path 40, the first fluid 70 enters the first introduction path 40 from the outside of the microfluidic device 100 through the first introduction port 42 and flows in the first introduction direction (arrow A direction). It reaches the junction 16 through the rectifying region 44 and the first buffer region 46.

  The shape of the cross section of the first introduction path at the first introduction port 42 is, for example, constant from the upstream side to the downstream side of the first fluid 70.

Further, the shape of the cross section of the first introduction path in the first rectifying region 44 is such that the flow width in the main flow path width direction gradually increases from the upstream side to the downstream side of the first fluid 70 and is perpendicular to the main flow path width direction. The channel depth in the direction (main channel depth direction) becomes gradually shallower.
Further, the shape of the cross section of the first introduction path in the first buffer region 46 is, for example, constant from the upstream side to the downstream side of the first fluid 70, and is the same shape as the cross section 16A.

  That is, by gradually changing the shape of the first introduction path cross section in the first introduction path 40 from the shape of the first introduction path cross section in the first introduction port 42 to the shape of the cross section 16A in the first rectifying region 44. The change in the area of the cross section of the first introduction path is reduced. Specifically, for example, the area of the first introduction path cross section is constant in more than two-thirds of the first rectifying region 44 in the first introduction direction on the first buffer region 46 side.

  Similarly to the first introduction path 40, the second introduction path 50 includes, for example, a second introduction port 52, a second rectification region 54, and a second buffer region 56. In the second introduction path 50, the second fluid 80 enters the second introduction path 50 from the outside of the microfluidic device 100 through the second introduction port 52 and flows in the second introduction direction (arrow B direction). It reaches the junction 16 through the two rectifying regions 54 and the second buffer region 56.

The shape of the second introduction path cross section at the second introduction port 52 is, for example, constant from the upstream side to the downstream side of the second fluid 80.
The shape of the cross section of the second introduction path in the second rectification region 54 is such that the flow path width in the main flow path width direction gradually increases from the upstream side to the downstream side of the second fluid 80 and is perpendicular to the main flow path width direction. The flow path depth in the direction becomes gradually shallower.

Further, in the second buffer region 56, for example, the groove 32 in the second flow path 30 is formed in a part of the second buffer region 56 (near the junction 16) from the junction 16 toward the upstream side of the second fluid 80. The groove region 58 is formed with a groove 82 similar to the above.
In FIG. 5, the surface where the groove 32 of the second flow path 30 is formed and the groove 82 of the second introduction path 50 in the junction 16 where the second introduction path 50 and the second flow path 30 communicate with the main flow path 10. The figure which expanded the surface in which was formed is shown. As shown in FIG. 5, the groove 82 is formed along the second introduction direction on the surface along the main flow path width direction in the second introduction path 50, and in the main flow path width direction (for example, at regular intervals). In parallel. That is, on the surface along the main flow path width direction of the second introduction path 50, for example, a plurality of partition plates 84 that separate the grooves 82 and the grooves 82 are provided in parallel in the main flow path width direction (for example, at regular intervals). ing.

The channel width in the main channel width direction in the groove 82 is the same as the channel width in the main channel width direction in the groove 32, and the interval between the groove 82 and the groove 82 (that is, the width in the main channel width direction of the partition plate 84). The distance between the groove 32 and the groove 32 is the same.
On the other hand, the flow path depth in the direction perpendicular to the main flow path width direction in the groove 82 is the same as the flow path depth in the main flow path depth direction in the groove 32 in the merging portion 16, but upstream of the second fluid 80. The groove 82 gradually becomes shallower, and after the groove region 58, the groove 82 does not exist. That is, in the groove region 58, the height of the partition plate 84 gradually decreases from the joining portion 16 toward the upstream side of the second fluid 80.

  The shape of the cross section of the second introduction path in the second buffer region 56 is, for example, constant until reaching the groove region 58 from the upstream side of the second fluid 80. In the groove region 58, the height of the partition plate 84 gradually increases from the upstream side or the downstream side of the second fluid 80, and the flow path depth (position of the groove 82 in the direction perpendicular to the main flow path depth). The flow path depth at (1) becomes higher and becomes the same shape as the cross section 16B.

  That is, also in the second introduction path 50, the shape of the second introduction path cross section is changed from the shape of the second introduction path cross section in the second introduction port 52 in the groove region 58 of the second rectifying region 54 and the second buffer region 56. By gradually changing to the shape of the cross section 16B, the change of the area of the second introduction path cross section is reduced. For example, also in the second rectification region 54, the area of the second introduction path cross section is constant in two or more of the lengths in the second introduction direction on the second buffer region 56 side.

<Discharge path>
Next, the discharge path 60 will be described.
As shown in FIG. 2, the discharge path 60 is communicated with the communication portion 18 in the main flow path 10, and the first fluid 70 and the second fluid 80 are transferred from the main flow path 10 to the discharge path 60 in the same direction as the main flow path direction. Discharged.
The discharge path 60 includes, for example, a discharge port 62 and a discharge rectification region 64 as shown in FIGS. In the discharge path 60, the first fluid 70 and the second fluid 80 flow in the discharge direction (arrow D direction) from the communication portion 18, pass through the discharge rectification region 64, and pass from the discharge port 62 to the outside of the microfluidic device 100. Discharged.

The shape of the cross section of the discharge path at the discharge port 62 is, for example, constant from the upstream side to the downstream side of the first fluid 70 and the second fluid 80, similarly to the first introduction port 42 and the second introduction port 52.
The shape of the discharge passage cross section in the discharge rectification region 64 is such that the flow passage width in the main flow passage width direction gradually decreases from the upstream side to the downstream side of the first fluid 70 and the second fluid 80, and the main flow passage width direction The channel depth in the vertical direction (main channel depth direction) gradually increases.
That is, by gradually changing the shape of the cross section of the discharge path in the discharge path 60 from the shape of the cross section of the main flow path in the communication portion 18 to the shape of the cross section of the discharge path in the discharge port 62 in the discharge rectification region 64. The change in area is small. Specifically, for example, the area of the discharge channel cross section is constant in more than two-thirds of the length of the discharge rectification region 64 in the discharge direction.

  In the microfluidic device 100 of the present embodiment described above, the first fluid 70 is disposed in the same direction as the main flow direction by using the main flow channel 10 in which the flow channel width in the main flow channel width direction is larger than the flow channel depth in the main flow channel depth direction. The second fluid 80 is introduced into the main channel 10 from the second introduction channel 50 at an acute angle from the depth direction of the main channel with respect to the main flow direction, and the first introduction is performed. Rectification in which the channel width in the main channel width direction becomes wider and the channel depth in the direction perpendicular to the main channel width direction becomes shallower as the channel 40, the second introduction channel 50, and the discharge channel 60 approach the main channel 10. There are regions (specifically, a first rectification region 44, a second rectification region 54, and a discharge rectification region 64, respectively).

Here, “introducing at an acute angle” means introducing at an angle smaller than 90 degrees. Specifically, the vector in the main flow direction and the vector in the main flow direction in the vector in the second introduction direction. It means that the components are introduced in the same direction.
In the present embodiment, the second fluid 80 is not limited to the form in which the second fluid 80 is introduced into the main flow path 10 from the second introduction path 50 at an acute angle with respect to the main flow direction, but from the second introduction path 50 to the main flow path 10 in the same direction as the main flow direction. It is also possible to adopt a form to be introduced.

If the microfluidic device 100 of this embodiment is used, due to the above configuration, the amount of processing per time in one microfluidic device 100 is large, and the first fluid 70 and the second fluid 80 in the main channel 10 It is possible to make it easy to form the interface uniformly in the main channel width direction from the junction 16 to the communication unit 18 in the main channel 10.
That is, in the microfluidic device 100 of the present embodiment, the flow path is smaller than the microfluidic apparatus using the micro flow path whose main flow path width in the main flow path width direction is not larger than the flow path depth in the main flow path depth direction. A wide width increases the amount of processing per hour.

In the microfluidic device 100 of the present embodiment, the second fluid is introduced from the second introduction path into the main flow path perpendicularly from the main flow path depth direction, and both the first fluid and the second fluid are different from the main flow direction. Compared to a configuration in which the second fluid 80 collides with the first fluid 70 in the merging portion 16, the collision energy can be suppressed to be smaller than that in the case where the second fluid 80 collides with the first fluid 70 from the direction (with an angle). For this reason, the flow of the first fluid 70 and the second fluid 80 in the main flow path 10 becomes stable and easily forms a laminar flow, and the interface between the first fluid 70 and the second fluid 80 in the main flow path 10 becomes the main flow path depth. It becomes easy to form perpendicular to the vertical direction.

  Furthermore, in the microfluidic device 100 of the present embodiment, the area of the first introduction path cross section and the second introduction path cross section is larger than that in the case where at least one of the first introduction path and the second introduction path does not have the rectifying region. Small change. That is, in this embodiment, since the 1st introduction path 40 and the 2nd introduction path 50 have the above-mentioned rectification field, the 1st introduction path section is changed without changing the areas of the 1st introduction path section and the 2nd introduction path section very much. The shape of the cross section of the second introduction path can be changed from the shape of the first introduction port 42 and the second introduction port 52 to the shapes of the cross section 16A and the cross section 16B having a large flow path width and a shallow flow path depth, respectively. it can. Therefore, the drift of the first fluid 70 and the second fluid 80 in the main channel 10 (that is, the flow rates of the first fluid 70 and the second fluid 80 vary in the main channel width direction, for example, the channel width The flow velocity in the vicinity of the center in the direction becomes faster than the flow velocity in the vicinity of both ends in the flow path width direction).

  Specifically, for example, when the flow path width is sharply widened from the upstream to the downstream in the first introduction path cross section or the second introduction path cross section while the flow path depth is constant, the area of the cross section suddenly increases. An expanding part occurs. As such, when there is a portion where the area of the first introduction path cross section or the second introduction path cross section suddenly increases, the pressure in the flow path decreases, and only the central portion of the fluid in the main flow path width direction easily flows. Will be faster. On the other hand, both ends in the main flow path direction of the fluid receive a force in a direction perpendicular to the direction in which the fluid flows, and are relatively slow. As described above, when a phenomenon in which the flow velocity is different in the channel width direction (that is, “diffusion”) occurs, the flow becomes unstable, and the interface between the first fluid 70 and the second fluid 80 extends in the main channel width direction. It becomes difficult to form. However, in the present embodiment, since the drift is suppressed compared to the above case, the flow of the first fluid 70 and the second fluid 80 is adjusted in the first introduction path 40 and the second introduction path 50, respectively, and the main flow path 10, the interface between the first fluid 70 and the second fluid 80 is easily formed over the entire main flow direction and the main flow path width direction.

  Moreover, in the microfluidic device 100 of this embodiment, the change in the area in the cross section of the discharge path is small as compared with the case where the discharge path does not have the rectifying region. That is, in this embodiment, since the discharge channel 60 has the rectifying region, the shape of the main channel cross section in the communication portion 18 having a large channel width and a shallow channel depth without changing much the area of the discharge channel cross section. The shape of the discharge channel cross section can be changed to the shape at the discharge port 62. Therefore, it is suppressed that pressure is applied to the first fluid 70 and the second fluid 80 from the direction perpendicular to the discharge direction in the discharge path 60, and the pressure applied in the discharge path 60 propagates to the main flow path 10 and flows into the main flow. Influencing the interface between the first fluid 70 and the second fluid 80 in the passage 10 is suppressed. As a result, in the present embodiment, the interface between the first fluid 70 and the second fluid 80 is easily formed over the entire main flow direction and the main flow channel width direction in the main flow channel 10.

Further, in the microfluidic device 100 of the present embodiment, the hydrophilic layer 22 is formed on the inner surface of the first channel 20, and the hydrophobic layer 38 is formed on the inner surface of the second channel 30.
Therefore, when the microfluidic device 100 according to the present embodiment is used, a hydrophilic fluid is used as the first fluid 70 and a hydrophobic fluid is used as the second fluid 80 as compared with the case where the hydrophilic layer 22 and the hydrophobic layer 38 are not formed. When the fluid is used, the interface between the first fluid 70 and the second fluid 80 in the main channel 10 is easily formed uniformly in the main channel width direction from the junction 16 to the communication unit 18 in the main channel 10.

  That is, since the microfluidic device 100 according to the present embodiment has the above configuration, the hydrophilic layer 22 and the hydrophilic fluid have high affinity, and thus the hydrophilic fluid is easily maintained in the first flow path 20. Further, since the affinity between the hydrophobic layer 38 and the hydrophobic fluid is high, the hydrophobic fluid is easily maintained in the second flow path 30. Therefore, when a hydrophilic fluid is used as the first fluid 70 and a hydrophobic fluid is used as the second fluid 70, the first fluid 70 and the second fluid 30 are positioned at the boundary surface 25 between the first fluid channel 20 and the second fluid channel 30. An interface with the second fluid 80 is easily formed. Therefore, the interface between the first fluid 70 and the second fluid 80 is prevented from rotating and formed along the depth direction of the main flow path, and the interface between the first fluid 70 and the second fluid 80 is defined as the main flow path 10. It is easy to form uniformly in the width direction of the main channel from the junction 16 to the communication part 18.

Further, in the microfluidic device 100 of the present embodiment, a titanium dioxide layer is used as the hydrophilic layer 22 and a glass member is used as the flow path lid 24. That is, in the present embodiment, when light is irradiated from the outside of the microfluidic device 100 from the flow path lid 24 side, the light passes through the flow path lid 24 and reaches the hydrophilic layer 22, and the titanium dioxide in the hydrophilic layer 22 absorbs the light. It has a structure that can be done. And titanium dioxide becomes super-hydrophilic by absorbing light and functions as a photocatalyst to promote, for example, a redox reaction.
Therefore, in the microfluidic device 100 of this embodiment, the hydrophilic layer 22 absorbs light and becomes superhydrophilic, so that the interface between the first fluid 70 and the second fluid 80 is parallel to the main channel width direction (that is, the photocatalyst. To be parallel to the surface of the titanium dioxide layer. That is, the interface is maintained in a wide state and is easily maintained in a state facing the hydrophilic layer 22 functioning as a photocatalyst at a short distance.

  Therefore, if the microfluidic device 100 of this embodiment is used, the photocatalytic reaction of titanium dioxide using the interface between two fluids, which has been difficult in the past, can be continuously performed. Since titanium dioxide that has absorbed light exhibits super hydrophilicity as described above, it is compatible with hydrophilic liquids such as water, acetonitrile, and alcohol, but is not easily compatible with hydrophobic liquids such as hexane and toluene. Therefore, it is difficult to carry out a photocatalytic reaction by bringing a hydrophobic liquid or a compound dissolved in a hydrophobic liquid into direct contact with titanium dioxide (for example, dispersing titanium dioxide particles in a hydrophobic liquid). It is. However, if the microfluidic device 100 of the present embodiment is used, the hydrophobic liquid or the like can be indirectly reacted (for example, oxidized) without directly contacting the hydrophobic liquid or the like with titanium dioxide.

  Specifically, for example, the first fluid 70, which is a water-soluble liquid, is brought into direct contact with the light-irradiated titanium dioxide to generate active species (for example, hydroxy radicals). Then, the active species moves to the interface between the first fluid 70 and the second fluid 80, which is a hydrophobic liquid, and acts (for example, oxidizes) on the compound contained in the second fluid 80. At this time, in the microfluidic device 100 of the present embodiment, the interface is in a state of facing the hydrophilic layer 22 (that is, titanium dioxide) at a short distance, so that active species generated on the surface of the hydrophilic layer 22 can easily reach the interface. . Moreover, in the microfluidic device 100 of this embodiment, since the said interface can be maintained widely, many active species can act on the compound contained in the 2nd fluid 80 in an interface compared with the case where an interface is narrow. That is, when the microfluidic device 100 according to the present embodiment is used, a conventionally difficult reaction (for example, a hydrophobic liquid itself, or a compound that is difficult to dissolve in a hydrophilic liquid and easily soluble in a hydrophobic liquid, etc.) is targeted. , Photocatalytic reaction of titanium dioxide, etc.) can be carried out efficiently.

Further, in the microfluidic device 100 of the present embodiment, the second flow path 30 is formed by a plurality of grooves 32 that are formed along the main flow direction and are arranged in parallel in the main flow path width direction.
Therefore, in the microfluidic device 100 of the present embodiment, the first fluid 70 and the second fluid 80 in the main channel 10 are compared with the case where the second channel is not divided by the partition plate and is one channel as a whole. Is easily formed evenly in the main channel width direction from the merging portion 16 to the communication portion 18.
That is, in the microfluidic device 100 of the present embodiment, the interface between the first fluid 70 and the second fluid 80 is divided due to the presence of the partition plate 34, so that the interface per one is compared with the case where the interface is not divided. The area of the interface is small, and it is suppressed that the interface rotates due to surface tension and becomes parallel to the depth direction of the main channel. Therefore, it is easy to maintain the interface between the first fluid 70 and the second fluid 80 in parallel with the main channel width direction.

In particular, in the form in which the hydrophilic layer 22 is formed on the inner surface of the first flow channel 20 and the hydrophobic layer 38 is formed on the inner surface of the second flow channel 30, the second flow channel 30 includes a plurality of grooves 32. This form is more desirable, and the interface between the first fluid 70 and the second fluid 80 in the main channel 10 is easily formed uniformly in the main channel width direction from the junction 16 to the communication unit 18.
That is, since the hydrophobic layer 38 is formed on the inner surface of the groove 32 constituting the second flow path 30, the second fluid 80 is easily maintained in the groove 32, thereby being guided to the first flow path 20. This is suppressed, and it becomes easier to maintain the interface parallel to the width direction of the main channel.

  In the present embodiment, the channel width and the channel depth of the main channel 10 are as described above, but the present invention is not limited to this as long as the channel width is larger than the channel depth. Specifically, for example, the channel depth of the main channel 10 is 1 mm or less and the channel width of the main channel 10 is larger than 1 mm. As described above, since the flow path depth of the main flow path 10 is shallow, an advantage as a micro flow path can be obtained, and the flow path width of the main flow path 10 is wide. The amount of processing can be increased.

Specific examples of the channel depth of the main channel 10 include a range of 10 μm to 1000 μm, a range of 25 μm to 1000 μm is preferable, and a range of 50 μm to 500 μm is more preferable.
When the channel depth is in the above range, it is easier to obtain the advantages as the micro channel than in the case where the channel depth is deeper than the above range, and the fluid flows at a lower pressure than in the case where the channel depth is shallower than the above range. Therefore, there is an advantage that the flow of the fluid becomes stable, the interface between the first fluid 70 and the second fluid 80 can be easily maintained in the main flow path width direction, and at the same time, the processing amount per time increases.

Moreover, specifically as a flow path width of the main flow path 10, the range of 1 cm or more and 20 cm or less is mentioned, for example.
When the flow path width is in the above range, the amount of processing per unit time is larger than in the case where the flow path width is narrower than the above range. An interface between the first fluid 70 and the second fluid 80 parallel to the width direction is easily formed.
Moreover, as a ratio of the channel width in the main channel width direction and the channel depth in the main channel depth direction in the main channel 10, the channel width is preferably 20 times or more and 1000 times or less of the channel depth. When the ratio between the channel width and the channel height is in the above range, the processing amount per hour is improved and the interface between the first fluid 70 and the second fluid 80 parallel to the main channel width direction is easily formed. It is possible to achieve both.

  In addition, the channel length in the main flow direction of the main channel 10 is determined by a preferable value depending on the flow rates of the first fluid 70 and the second fluid 80, the time required for the target processing, and the like. The range of 3 cm or more and 30 cm or less is mentioned.

  In the present embodiment, the shapes of the main flow path cross section, the first flow path cross section, and the second flow path cross section are constant from the merging portion 16 to the communication portion 18, but are not limited thereto. However, from the viewpoint of maintaining the interface between the first fluid 70 and the second fluid 80 in the main channel width direction, the areas of the main channel cross section, the first channel cross section, and the second channel cross section communicate with each other from the junction 16. It is desirable that the portion 18 is constant. When the area of the main channel cross section is not constant, it is desirable that the ratio of the area of the first channel cross section and the area of the second channel cross section is constant from the junction 16 to the communication unit 18. Here, “the area is constant” means that the maximum value in the area is 1 to 1.05 times the minimum value.

  In the present embodiment, the channel depth of the first channel 20 and the channel depth of the second channel 30 are the same, but the present invention is not limited to this. However, it is desirable to set the position of the boundary surface 25 between the first flow path 20 and the second flow path 30 to a desirable position where an interface is to be formed. The position of the interface between the first fluid 70 and the second fluid 80 varies depending on the characteristics such as the viscosity of the first fluid 70 and the second fluid 80 and the conditions such as the flow velocity, and the purpose of application (for example, when used for a chemical reaction). The preferred position of the interface may vary depending on the reaction system and the like. For example, as in the present embodiment, when a titanium dioxide layer is used as the hydrophilic layer 22 and applied to a photocatalytic reaction by titanium dioxide using the interface, the channel depth of the first channel 20 is the second channel 30. The flow path depth is preferably 0.1 times or more and 1 time or less.

In the present embodiment, the first channel cross section is rectangular, but is not limited to this, for example, a shape in which a part or all of the corners of the quadrangle are rounded, a side parallel to the main channel depth, and the main channel width For example, a shape having a curved side may be used.
Further, in the present embodiment, the groove cross section is a square, but is not limited to this, for example, a rectangle, a quadrangular shape in which some or all of the corners are rounded, a side parallel to the main channel depth and the main channel width For example, a shape having a curved side may be used.
In the present embodiment, the channel width in the groove cross section is 100 μm, which is the same as the channel depth, but is not limited thereto. Examples of the channel width in the groove cross section include a range of 100 μm to 500 μm, and examples include a range of 1 to 5 times the channel depth in the groove cross section.
In the present embodiment, the width of the partition plate 34 in the main flow path width direction is 100 μm. However, the width is not limited to this, and the smaller the width, the better the dead space is reduced and a wide interface is easily obtained. Specifically, from the viewpoints of durability against pressure by the second fluid 80, compatibility between workability and reduction of dead space, for example, a range of 20 μm or more and 100 μm or less is exemplified. Further, the width of the partition plate 34 may not be the same among the plurality of partition plates 34.

  In the present embodiment, the second flow path 30 is composed of a plurality of grooves 32. However, the first flow path 20 may be composed of a plurality of grooves, and the first flow path 20 and the second flow path. The path 30 may be configured with a plurality of grooves, and neither the first flow path 20 nor the second flow path 30 may be configured with grooves. However, the main flow path in the partition plate 34 is different from the other forms in that only one of the first flow path 20 and the second flow path 30 is configured by a plurality of grooves as in the present embodiment. Since an interface in contact with the surface 36 in the width direction is easily formed, the interface between the first fluid and the second fluid is preferably maintained in the same direction as the main channel width direction.

Further, in the present embodiment, the hydrophilic layer 22 is formed on the inner surface of the first flow path 20, but the hydrophilic layer 22 is formed on at least a surface parallel to the main flow path width direction among the inner surfaces of the first flow path 20. The form in which the hydrophilic layer 22 is not formed may be sufficient.
And when forming the hydrophilic layer 22, as a material used for the hydrophilic layer 22, it is not restricted to titanium dioxide, For example, a silicon polymer, another hydrophilic organic polymer, etc. are mentioned.
In the present embodiment, the inner surface of the second flow channel 30 (that is, the surface of the inner surface of the groove 32 other than the surface in contact with the first flow channel 20) and the surface 36 of the partition plate 34 in the main flow channel width direction are provided. Although the hydrophobic layer 38 is formed, the hydrophobic layer 38 may be formed only on the inner surface of the second flow path 30, or the hydrophobic layer 38 may not be formed.
When the hydrophobic layer 38 is formed, examples of the material used for the hydrophobic layer 38 include a material in which a hydrophobic functional group such as an octadecyl group is arranged, a hydrophobic organic polymer, and the like.

  In the present embodiment, in order to allow light to reach the hydrophilic layer 22 that is a titanium dioxide layer, a light-transmitting material is used as the material of the channel lid 24 (that is, the first flow in which the hydrophilic layer 22 is formed). The surface along the width direction of the main channel in the channel 20 is light transmissive). Therefore, the material of the hydrophobic layer 38 may be a material having light transparency or a material having no light transparency.

  Even when a titanium dioxide layer is used as the hydrophilic layer 22, the hydrophobic layer 38 is light transmissive and is formed on the surface of the second flow path 30 along the width direction of the main flow path. The material of the flow path lid 39, which is a member in contact with the layer 38, may be any material having the above-described light transmittance. If the hydrophobic layer 38 and the flow path cover 39 have a light-transmitting form, the flow path cover outside the microfluidic device 100 can be obtained by using a light-transmitting fluid as the first fluid 70 and the second fluid 80. Light irradiated from the 39 side reaches the hydrophilic layer 22 which is a titanium dioxide layer. Therefore, the material of the flow path lid 24 may be a material having the above light transmittance or a material not having the above light transmittance.

Examples of the light-transmitting material include resin (in addition to glass (eg, quartz glass, Pyrex (registered trademark) glass)). Moreover, as the material having the light transmission property, a material that transmits light having a wavelength of 365 nm is preferable among the above materials.
In addition, the material used when the light-transmitting material may be used or the light-transmitting material may be used. In addition to the glass and the resin, an inorganic material such as a metal is also used. Can be mentioned.

Moreover, in this embodiment, although the thickness of the hydrophilic layer 22 is as above-mentioned, it is not restricted to this. For example, when a titanium dioxide layer is used as the hydrophilic layer 22 as in this embodiment, the thickness is preferably 0.1 μm or more from the viewpoint of the photocatalytic function of titanium dioxide.
When a titanium dioxide layer is used as the hydrophilic layer 22 and a light-transmitting member is used as the flow path cover 24 as in the present embodiment, irradiation from the flow path cover 39 side outside the microfluidic device 100 is performed. It is desirable to cause the light that has reached the surface in contact with the first fluid 70 in the hydrophilic layer 22. From this point of view, it is desirable that the hydrophilic layer 22 has a thickness such that the titanium dioxide layer is light transmissive, and specifically, 1 μm or less. On the other hand, when a layer of titanium dioxide is used as the hydrophilic layer 22 and the hydrophobic layer 38 and the channel lid 39 are light transmissive, light can be irradiated from the channel lid 39 side outside the microfluidic device 100. Therefore, the hydrophilic layer 22 may have a thickness of 1 μm or more.
Moreover, when using layers other than titanium dioxide as the hydrophilic layer 22, it is preferable from the viewpoint of exhibiting the hydrophilic property of the hydrophilic layer 22 that the thickness of the hydrophilic layer 22 is 0.1 μm or more.

On the other hand, the thickness of the hydrophobic layer 38 is not particularly limited, but is preferably 0.1 μm or more from the viewpoint of exerting the hydrophobicity of the hydrophobic layer 38, and specifically, for example, a range of 0.1 μm or more and 1 μm or less. Is mentioned.
When the hydrophobic layer 38 having optical transparency is used as described above, for example, octadecyltrimethoxysilane or the like is used as the material of the hydrophobic layer 38, and the thickness of the hydrophobic layer 38 is in the range of 0.1 μm to 1 μm. The form to do is mentioned.

Further, in the present embodiment, the angle of the merging angle θ at the merging portion 16 is 15 degrees, but is not limited to this. For example, the merging angle θ is 0 degree or more and 60 degrees or less. The angle is preferably 30 degrees or less and more preferably smaller.
In the present embodiment, the second introduction path 50 is a straight flow path, but is not limited thereto, and the second introduction path 50 may be a curved flow path.
For example, as shown in FIG. 4, the second introduction path 50 may be a curved path, and the angle of the merging angle θ in the merging portion 16 may be 0 degree.

The length along the first introduction direction of the first rectification region 44 and the length along the second introduction direction of the second rectification region 54 are preferably ranges depending on the flow rates of the first fluid 70 and the second fluid 80, respectively. However, for example, a range of 2 cm to 6 cm can be mentioned.
Further, the length along the discharge direction of the discharge rectification region 64 is also preferably as long as possible.

Further, the first introduction path 40, the second introduction path 50, and the discharge path 60 only need to have the first rectification region 44, the second rectification region 54, and the discharge rectification region 64, respectively, and have other regions. You don't have to.
In the present embodiment, since the flow of the first fluid 70 and the second fluid 80 is adjusted in the first introduction path 40, the second introduction path 50, and the discharge path 60, in particular, the first introduction port 42 and the second introduction port. 52 and the discharge port 62 may have any shape or may not be provided.
On the other hand, the first buffer region 46 and the second buffer region 56 may not be particularly provided. However, when the first buffer region 46 or the second buffer region 56 is provided, the flow of the first fluid 70 or the second fluid 80 arranged in the first introduction channel 40 or the second introduction channel 50 is not disturbed. Therefore, it is desirable that the cross-sectional area of the first introduction path section or the second introduction path section be constant from the upstream side to the downstream side.
Furthermore, the partition plate 84 may not be provided in the second buffer region 56.

The manufacturing method of the microfluidic device 100 in the present embodiment is not particularly limited, and can be manufactured by a known method.
Specifically, for example, the first metal plate is three-dimensionally carved to form part of the second introduction path 50, the second flow path 30, and the discharge path 60, and the second flow path in the first metal plate is formed. A hydrophobic layer 38 is formed on 30. Next, one surface of the second metal plate is three-dimensionally carved to form a part of the first introduction path 40, and the second metal plate is placed on the first metal plate to cover the second introduction path 50. do. Then, a part of the first introduction path 40, the first flow path 20, and a part of the discharge path 60 are formed on the glass plate, and the hydrophilic layer 22 is formed in the first flow path 20. Finally, the microfluidic device 100 is formed by placing a glass plate on the first metal plate and the second metal plate and covering the first introduction path 40, the main flow path 10, and the discharge path 60.

  As described above, the microfluidic device of the present invention uses two fluids flowing through the wide microchannel of the microfluidic device. The combination of the first fluid and the second fluid is not particularly limited, and examples thereof include liquid and liquid, gas and liquid, or gas and gas. There may be.

In particular, since the microfluidic device of the present invention easily forms an interface along the main channel width direction in the main channel as described above, two types of low compatibility are combined as a combination of the first fluid and the second fluid. A liquid or a combination of a gas and a liquid can be used, and can be suitably applied to a process (for example, chemical reaction or extraction) at the interface between them. Examples of the two liquids having low compatibility include a combination of a hydrophilic liquid and a hydrophobic liquid such as water and oil.
Further, when the hydrophilic layer 22 is formed on the inner surface of the first channel 20 and the hydrophobic layer 38 is formed on the inner surface of the second channel 30 as in the above embodiment, the first fluid 70 and the second fluid 80 are formed. It is desirable to apply a combination of a hydrophilic liquid and a hydrophobic liquid as a combination of
On the other hand, when a combination of gas and liquid is used as the combination of the first fluid 70 and the second fluid 80, a hydrophilic layer is formed on the inner surface of the flow path for flowing gas among the first flow path and the second flow path. Alternatively, it is preferable not to form a hydrophobic layer.

(Test example)
A test was performed using the microfluidic device 100 of the first embodiment.
Note that the channel width of the first channel and the channel width of the second channel in the microfluidic device used were the same. In addition, a titanium dioxide layer was formed as the hydrophilic layer 22 in the first channel 20, and quartz glass was used as the material of the channel lid 24. In addition, the groove 32 (that is, the partition plate 34) is formed in the second flow path 30, and the groove 82 (that is, the partition plate 84) in the second buffer region 56 is also provided. Further, when the hydrophilic layer 22 is formed, the thickness of the hydrophilic layer 22 is 0.2 μm, and when the hydrophobic layer 38 is formed, the thickness of the hydrophobic layer 38 is 1 μm or less.

Moreover, the formation method of the hydrophilic layer 22 is as follows. Titanium dioxide was used as the material for the hydrophilic layer 22. Specifically, a 0.5 M acetylacetone solution of titanium triisopropoxide (Ti-(— O-iso-C ₃ H ₇ ) ₄ ) is placed on the substrate (the channel lid 24 in which the first channel 30 is formed). A titanium dioxide film was formed by a sol-gel method of spin coating and treating at 450 ° C. for 2 hours.
Furthermore, the formation method of the hydrophobic layer 38 is as follows. Specifically, a 1% toluene solution of trichlorooctadecylsilane is applied to the channel lid 39 in which the second channel 30 is formed (for example, when the hydrophobic layer 38 is partially formed), or the second channel is closed. 30 (for example, when the hydrophobic layer 38 is uniformly formed in the entire flow path), excess octadecyl groups were washed and removed with toluene to form the hydrophobic layer 38.

<Interface visualization test>
The following first fluid and second fluid are used as the first fluid and the second fluid, and the fluid is caused to flow through the created microfluidic device of FIG. 1 under the following flow velocity conditions (conditions 1 to 8). By coloring either one of the two fluids or by coloring both the first fluid and the second fluid different from each other, the interface between the first fluid and the second fluid was directly visually observed.

In the following conditions 1 to 4, the following first fluid A and second fluid A were used as the first fluid and the second fluid.
First fluid A: pure water Second fluid A: toluene Conditions 1 to 4 are as follows.
Condition 1: Flow rate of the first fluid A is 2.0 μm / s, Flow rate of the second fluid A is 2.0 μm / s
Condition 2: Flow rate of first fluid A 3.3 μm / s, flow rate of second fluid A 2.0 μm / s
Condition 3: Flow rate of the first fluid A is 2.0 μm / s, Flow rate of the second fluid A is 3.3 μm / s
Condition 4: Flow rate of the first fluid A is 2.0 μm / s, Flow rate of the second fluid A is 3.3 μm / s

  In the above conditions 1 and 2, laminar flows of the first fluid A and the second fluid A are formed, and the interface between the first fluid A and the second fluid A is formed in parallel to the main channel width direction. However, no drift was confirmed. On the other hand, in condition 3, a partial drift was confirmed. In condition 4, severe drift was confirmed.

In Condition 5 to Condition 8, the following first fluid B and second fluid B were used as the first fluid and the second fluid.
First fluid B: pure water Second fluid B: methanol Conditions 5 to 8 are as follows.
Condition 5: Flow rate of the first fluid B 0.7 μm / s, flow rate of the second fluid B 0.7 μm / s
Condition 6: Flow rate of the first fluid B of 2.0 μm / s, flow rate of the second fluid B of 2.0 μm / s
Condition 7: Flow rate of the first fluid B 3.3 μm / s, flow rate of the second fluid B 2.0 μm / s
Condition 8: Flow rate of first fluid B 4.5 μm / s, flow rate of second fluid B 2.0 μm / s

  In the above conditions 5, 6, and 7, laminar flow of the first fluid B and the second fluid B is formed, and the interface between the first fluid B and the second fluid B is formed in parallel with the main channel width direction. It was confirmed that no drift was observed. On the other hand, in condition 4, it was confirmed that turbulent flow occurred.

From the above results, for example, in the conventional wide microfluidic device, even if it is impossible to form an interface parallel to the main flow path width direction, the microfluidic device of the present invention is used in parallel to the main flow path width direction. It can be seen that a simple interface can be formed. In particular, in conditions 1 to 4 using pure water and toluene among the above results, the conventional wide microfluidic device (particularly, the first introduction path 40, the second introduction path 50, and the discharge path 60 have a rectification region). It was impossible to form an interface parallel to the main channel width direction in the main channel of the wide micro device), but as shown in the above test example, the micro fluid device of the present invention is mainly used. It can be seen that an interface parallel to the road width direction is formed.

<Photocatalytic reaction test>
In the prepared microfluidic device 100 of FIG. 1, the following test was performed in order to confirm that the drift of the first fluid and the second fluid in the main channel 10 is suppressed.
As the first fluid C and the second fluid C, a 0.1% acetonitrile solution of p-methoxytoluene is used, and the fluid is passed through the microfluidic device 100 to emit light (light irradiation intensity 500 mW / cm ⁻² , light Irradiation time 140 seconds). The reaction yield was determined from the amount of anisaldehyde (p-methoxybenzaldehyde) produced by the oxidation reaction of p-methoxytoluene by the photocatalytic action of titanium dioxide, and the efficiency of the reaction was evaluated.

Specifically, the total injection amount of the first fluid C and the second fluid C was set to 120 μl / min, and the photocatalytic reaction with the titanium dioxide was performed. As a result, anisaldehyde was produced with a yield of 3.0%.
For comparison, a similar test was performed using a single channel microreactor having a channel width of 500 μm and a channel depth of 25 μm. The fluid injection amount was 0.5 μl / min, and the anisaldehyde yield was It was 4.6%.

  From the above results, in the test example using the microfluidic device of the present invention, the amount of anisaldehyde synthesized per hour compared to the conventional microfluidic device in which the channel width direction and the channel depth direction are 1 mm or less. It can be seen that has increased to 157 times. Furthermore, from the above results, in the test example using the microfluidic device of the present invention, the yield of anisaldehyde is equivalent to the yield when using the conventional microfluidic device, and the main channel (wide microchannel) It can be seen that the drift in the) is suppressed.

DESCRIPTION OF SYMBOLS 10 Main flow path 16 Merge part 16A Section 16B Cross section 16C Merge line 18 Communication part 20 1st flow path 22 Hydrophilic layer 24 Flow path cover 25 Boundary surface 28 Hydrophobic layer 30 Second flow path 32 Groove 34 Partition plate 36 Main flow path width direction Surface 38 Hydrophobic layer 39 Flow path lid 40 First introduction path 42 First introduction port 44 First rectification region 45 Merge angle 46 First buffer region 50 Second introduction channel 52 Second introduction port 54 Second rectification region 56 Second buffer Region 58 Groove region 60 Discharge path 62 Discharge port 64 Discharge rectification region 70 First fluid 80 Second fluid 82 Groove 84 Partition plate 100 Microfluidic device

Claims (4)

A main flow path in which the first fluid and the second fluid flow in contact with each other, and in the main flow path depth direction, which is a direction perpendicular to the main flow direction in which the first fluid and the second fluid flow in the main flow path. The length of the main flow path width direction which is a direction perpendicular to the main flow path depth direction in the cross section perpendicular to the main flow direction in the main flow path is composed of the first flow path and the second flow path arranged in parallel. A main flow path larger than the length in the direction of the path depth;
A first introduction path that communicates with the upstream end of the first flow path in the main flow direction and introduces the first fluid into the first flow path in the same direction as the main flow direction; The length in the same direction as the width direction of the main channel in the cross section perpendicular to the first introduction direction from the upstream side to the downstream side in the first introduction direction, which is the direction in which the first fluid flows in one introduction path. A first introduction path that gradually increases and has a region in which the length in the direction perpendicular to the main flow path width direction gradually decreases;
The second fluid is communicated with an end on the upstream side in the main flow direction in the second flow path, and the second fluid is placed in the same direction with respect to the main flow direction or at an acute angle with respect to the main flow direction from the direction side of the main flow path depth. A second introduction path to be introduced into the second flow path, wherein the second fluid flows in the second introduction path from the upstream side in the second introduction direction toward the downstream side in the second introduction direction. A second introduction path having a region in which the length in the same direction as the main channel width direction in the vertical cross section gradually increases and the length in the direction perpendicular to the main channel width direction gradually decreases;
A discharge path that communicates with an end of the main flow path downstream in the main flow direction and discharges the first fluid and the second fluid from the main flow path in the same direction with respect to the main flow direction; The length in the same direction as the width direction of the main channel in the cross section perpendicular to the discharge direction is gradually reduced from the upstream side to the downstream side in the discharge direction in which the first fluid and the second fluid flow. And a discharge channel having a region in which the length in the direction perpendicular to the main channel width direction gradually increases.   The microfluidic device according to claim 1, wherein a hydrophilic layer is formed on an inner surface of one of the first channel and the second channel, and a hydrophobic layer is formed on the other inner surface.   Of the first channel and the second channel, the surface along the main channel width direction in the channel in which the hydrophilic layer is formed, and the channel in the channel in which the hydrophobic layer and the hydrophobic layer are formed. 3. The microfluidic device according to claim 2, wherein at least one of the surface along the width direction of the main flow path is light transmissive, and the hydrophilic layer is a titanium dioxide layer.   4. The device according to claim 1, wherein at least one of the first flow path and the second flow path includes a plurality of grooves formed along the main flow direction and arranged in parallel with the main flow path width direction. 5. The microfluidic device according to claim 1.

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