JP2014138970A - Substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate capable of producing fine droplets efficiently and stably.SOLUTION: The substrate comprises: a first base plate 101; a first recess 102 which is formed on one surface 101a of the first base plate 101 and serves as a channel of first liquid L1; a second recess 103 which is formed on the one surface 101a and serves as a channel of second liquid L2; a second base plate 105 overlapped to the one surface 101a so that the first and second recesses 102, 103 are covered; and a fine hole 104 communicating an internal space surrounded by the second base plate 105 and the first recess 102 and an internal space surrounded by the second base plate 105 and the second recess 103 in the inside of the first base plate 101 and into which the first liquid L1 or the second liquid L2 can be flown from one internal space to the other internal space. A step d3 is formed between an internal side surface on an opening of the fine hole 104 and one surface 105a of the second base plate forming an overlapped surface with the one surface 101a of the first base plate.

Description

  The present invention relates to a substrate having a microstructure formed using laser light and functioning as a micro / nanochannel chip.

  Microtechnology in recent years is spreading as a technology that can be applied not only to the electrical and electronic fields but also to various fields such as machinery, light, fluids, biotechnology, and chemicals, and the development of small devices in each field Is underway. In particular, in the field of biotechnology and chemicals, a droplet produced using a device functioning as a micro / nano channel (micro / nano channel chip) has attracted attention. The droplet functions as a local space in which a plurality of types of fluids are mixed at high speed and in a controllable manner to produce microparticles of a desired size. By using this droplet, it is possible to analyze characteristics and the like of microparticles having a desired size.

  As a structure of a base body that is a main part of a device for manufacturing a droplet, those shown in FIGS. 7A and 7B are known. FIG. 7 is a plan view schematically showing a configuration of a part 500 of the base body which is a main part of the device. A part 500 of the base body is provided with a first recess 502 that functions as a fluid flow path and a fine hole 504 connected to the side wall 502a of the first recess on one surface 501a of the substrate 501. A cap (not shown) is overlaid on one surface 501a of the substrate, and the first fluid and the second fluid are caused to flow through the first recess 502 and the fine hole 504 simultaneously. Then, by discharging the second fluid from the fine hole 504 to the first recess, the discharged second fluid is cut by receiving pressure due to the flow of the first fluid, and the droplet D is produced.

  However, since the first recess 502 and the fine hole 504 constituting the flow path of FIG. 7 are produced by photolithography and etching, both are open on the one surface 501a of the substrate. That is, the opening surface 502 a and the fine hole 504 a of the first recess are all aligned on one surface 501 a of the substrate, that is, the overlapping surface 505 a with the cap 505. Therefore, since the second fluid discharged from the fine hole 504 spreads wet along the overlapping surface 505a of the cap, the produced droplet D has a large particle size of about 10 μm (Non-Patent Document). 1).

  On the other hand, what is shown in FIG. 8 is also known as a structure of a base body which is a main part of a device for producing droplets. FIG. 8 is a plan view schematically showing the configuration of a part 600 of the base body that is a main part of the device. A part 600 of the base body includes, on one surface 601a of the substrate 601, a first recess 602 that functions as a fluid flow path and fine holes 604 and 606 that are connected to the side walls 602a and 602b of the first recess, respectively. . A cap (not shown) is overlaid on the one surface 601a of the substrate, and the first fluid and the second fluid are caused to flow simultaneously through the first recess 602 and the fine hole 604, respectively. The first fluid flows from the first recess 602 into the third recess 606 by allowing the second fluid to be discharged from the fine hole 604 through the first recess 602 to the third recess 606. The droplet D is produced by being cut by receiving the pressure of the flow.

  According to the configuration of FIG. 8, a droplet D having a size of about 3 μm can be obtained (Non-Patent Document 2). However, since the small droplets of about 3 μm listed in Non-Patent Document 2 are formed simultaneously with the large droplets, it is necessary to have a structure for sorting them in the flow path. Considering that it will be wasted if there is no application to be used, it is difficult to say that it is optimal in industries that require efficient production.

  In the field of biotechnology, in order to produce small particles of about several μm or less, the size of the flow path (recessed portion) for discharging the fluid that can be a droplet is not more than micro order. Is required.

Wei-Heong Tan and Shoji Takeuchi, “Monodisperse Alginate Hydrogel Microbeads for Cell”, Adv. Mater. 2007, 19, 2696-2701. Yung-Chieh Tan, Vittorio Cristini, Abraham P. Lee, “Monodispersed microfluidic droplet generation by shear focusing microfluidic device”, Sensors and Actuators B, 2005

  The present invention has been made in consideration of the above points, and an object of the present invention is to provide a substrate capable of efficiently and stably manufacturing a minute droplet.

  The substrate according to claim 1 of the present invention is formed on a first substrate, a first recess formed on one surface of the first substrate, forming a flow path for a first fluid, and one surface of the first substrate. A second recess forming a flow path for the second fluid, a second substrate overlaid on one surface of the first substrate so as to cover the first recess and the second recess, and an interior of the first substrate The internal space surrounded by the second substrate and the first recess and the internal space surrounded by the second substrate and the second recess are communicated with each other and directed from one internal space to the other internal space. And the second substrate that forms an overlapping surface of the inner surface of the opening of the minute hole and one surface of the first substrate. A step is provided between the first surface and the second surface.

  According to the structure of the base body according to claim 1, since the step is provided between the inner side surface in the opening of the microhole and the one surface of the second substrate which forms the overlapping surface with the one surface of the first substrate. The second fluid ejected from the micropores is difficult to spread along the overlapping surface of the second substrate and the bottom surface of the first recess. Therefore, it is possible to prevent the droplet from being formed larger than a desired size by spreading the second fluid along one surface of the second substrate. Therefore, a minute droplet can be manufactured stably.

  The substrate according to claim 2 of the present invention is that, in claim 1, at least a part of the opening of the fine hole is disposed at a position overlapping the central region in the depth direction of the first recess. Features.

  According to the structure of the base body according to claim 2, the first fluid has a wall surface at a position farther from the wall surface of the flow path formed by the inner wall surface of the first recess and the overlapping surface of the second substrate in the flow path. The effect of the is reduced, can flow faster. That is, the flow rate of the first fluid is maximized at the center in the flow path. Therefore, at least a part of the second fluid discharged from the opening of claim 2 enters the central portion of the flow path, and receives a large pressure from the portion of the first fluid having the maximum flow velocity. As a result, the discharged second fluid is likely to be cut, and small-sized droplets can be manufactured in large quantities at high speed.

  The substrate according to claim 3 of the present invention is characterized in that, in claim 1 or 2, the minor diameter of the micropore is 20 nm or more and 10 μm or less.

  According to the structure of the base body according to claim 3, by setting the minor diameter of the micropore to 20 nm or more, the pressure necessary for discharging the second fluid becomes too large, and the discharge itself becomes difficult. It can be avoided. In addition, by setting the minor diameter of the micropore to 20 nm or more, it is possible to prevent damage to the device due to the pressure required for ejection exceeding the bonding strength of the cap.

  Further, according to the configuration of the base body according to claim 3, by setting the minor diameter of the micropore to 10 μm or less, the resistance against the pressure due to the flow of the first fluid is reduced, and the second fluid is easily cut. Therefore, small droplets of several microns or less can be efficiently produced.

  The substrate according to a fourth aspect of the present invention is the substrate according to any one of the first to third aspects, wherein the flow rate of the second fluid is 0.001 to 10 times the flow rate of the first fluid. It is characterized by.

  According to the configuration of the base body according to claim 4, by setting the flow rate of the second fluid to 0.001 times or more of the flow rate of the first fluid, the discharged second fluid maintains its shape, A certain distance can be advanced toward the center of the flow path. Therefore, since the discharged second fluid is subjected to pressure due to the flow of the first fluid at a position where the flow velocity is higher, the discharged second fluid can be easily cut and the droplet can be efficiently produced. Can do.

  Moreover, according to the structure of the base | substrate which concerns on Claim 4, by making the flow rate of a 2nd fluid into 10 times or less of the flow rate of a 1st fluid, the discharged 2nd fluid maintained the shape, It is possible to prevent reaching the inner wall of the flow channel facing the opening. Therefore, the discharged second fluid can receive pressure due to the flow of the first fluid, and can be cut by this pressure to produce a droplet.

  According to the base body of the present invention, since the step is provided between the inner surface of the opening of the microhole and the one surface of the second substrate that forms the one surface of the first substrate, The discharged second fluid is unlikely to spread on the overlapping surface of the second substrate and the bottom surface of the first recess. Therefore, it is possible to prevent the droplet from being formed larger than a desired size by spreading the second fluid along one surface of the second substrate. Therefore, a minute droplet can be manufactured stably.

It is a top view which shows typically the structure of the device provided with the base | substrate by this invention. (A) It is a top view which shows typically the structure of the base | substrate by this invention. (B) It is sectional drawing which shows the structure of the base | substrate by this invention typically. It is a process flow explaining the manufacturing method of the base by the present invention step by step. It is sectional drawing of the to-be-processed object which demonstrates the manufacturing method of the base | substrate by this invention in steps. (A) It is a perspective view of the flow path of the 1st fluid which comprises the base | substrate by Example 1 of this invention. (B), (c) It is a figure which shows the simulation result regarding distribution of the flow velocity of the 1st fluid in a flow path. It is a graph regarding the size of the droplet manufactured using the base | substrate by Example 2 of this invention. It is a top view which shows typically the structure of the base | substrate by a prior art. It is a top view which shows typically the structure of the base | substrate by a prior art. (A), (b) It is a photograph which shows the result of Example 3 of this invention.

  Hereinafter, based on a preferred embodiment, the present invention will be described with reference to the drawings. The following embodiments are described by way of example in order to better understand the gist of the invention, and do not limit the present invention unless otherwise specified. In addition, in the drawings used in the following description, in order to make the features of the present invention easier to understand, the main part may be enlarged for convenience, and the dimensional ratios of the respective components are the same as the actual ones. Not necessarily.

<First embodiment>
The configuration of the chip 150 including the base body 100 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a plan view schematically showing the configuration of the chip 150. The chip 150 includes a substrate 110, a first fluid supply unit 111, a second fluid supply unit 112, a droplet production unit 113, a first fluid and droplet storage unit 114, and a discharge unit 115. .

The droplet manufacturing means 113 includes a plurality of substrates 100. One end of the first flow path 102 communicating with each base body 100 is connected to the supply means 111, and the other end is connected to the storage means 114. The storage means 114 and the discharge means 115 are connected via the fourth flow path 116. One end of the second flow path 103 communicating with each base body 100 is connected to the supply means 112. The first flow path 102 and the second flow path 103 are connected by a fine hole 104.
In order to clearly show the configuration of the chip 150, FIG. 1 shows a state in which the first flow path 102, the second flow path 103, and the fourth flow path 116 are exposed. The flow paths are all covered by a second substrate (not shown) described later.

[Structure of substrate]
The configuration of some of the substrates 100 included in the droplet manufacturing means 113 will be described with reference to FIG. FIG. 2A is a plan view schematically showing the configuration of the base 100 in FIG. As in FIG. 1, in order to clearly show the configuration of the first flow path 102, the second flow path 103, and the micropores 104, the inside of the base body 100 is partially transparentized. FIG. 2B is a cross-sectional view of the substrate 100 taken along the line AA in FIG.

  The base body 100 includes the first substrate 101, the first recess 102 and the second recess 103 formed on the one surface 101a of the first substrate, and the first recess 102 and the second recess 103 so as to be covered. And a second substrate 105 overlaid on one surface 101a. The 1st recessed part 102 and the 2nd recessed part 103 have comprised the flow path of the 1st fluid L1, and the flow path of the 2nd fluid L2, respectively.

  In addition, the base body 100 communicates with the internal space surrounded by the second substrate 105 and the first recess 102 and the internal space surrounded by the second substrate 105 and the second recess 103 inside the first substrate 101. Micropores 104. The fine holes 104 allow the first fluid L1 or the second fluid L2 to flow from one internal space toward the other internal space.

  As the first substrate 101, for example, an amorphous substrate made of glass having high chemical resistance and excellent workability, or a crystalline substrate made of quartz, silicon, sapphire, or the like is used. In the first embodiment, a substrate having a fine hole in a flat substrate is shown as an example. However, the shape of the substrate is not limited in providing the fine hole in the substrate, and the substrate can be arbitrarily formed. It may be replaced with a shaped substrate.

  The first recess 102 has a linearly extending shape so that the first fluid supply source 111 and the droplet manufacturing unit 113 and the droplet manufacturing unit 113 and the storage unit 114 are connected to each other. The second recess 103 has a linearly extending shape so as to connect the first fluid supply source 111 and the droplet manufacturing means 113. It is desirable that the longitudinal direction of the second recess 103 is perpendicular to the longitudinal direction of the first recess 102 at the position where the first recess 102 and the second recess 103 are connected.

  With such a configuration, when the first fluid L1 and the second fluid L2 are flowed, the flow direction f2 of the second fluid L2 in the micropore 104 is the flow of the first fluid L1 in the first recess 102. It is perpendicular to the direction f1. Therefore, since the pressure due to the flow of the first fluid L1 acts perpendicularly to the longitudinal direction of the second fluid L2 discharged from the fine holes 104, the second fluid L2 can be easily cut. The droplet D can be produced efficiently.

  The cross section of the fine hole is substantially elliptical. Of the major axis and the minor axis of the elliptical shape, the minor axis d1 is desirably 20 nm or more and 10 μm or less. When the minor axis d1 is 20 nm or more and 10 nm or less, the second fluid L2 can be easily discharged.

  By setting the minor diameter d1 of the fine holes to 20 nm or more, it is possible to avoid a situation in which the pressure necessary for discharging the second fluid L2 becomes too large and the discharge itself becomes difficult. In addition, by setting the minor diameter d1 of the fine holes to 20 nm or more, it is possible to prevent damage to the device due to the pressure required for ejection exceeding the bonding strength of the second substrate (cap) 105.

  By setting the minor diameter d1 of the micropore to 10 μm or less, the resistance against the pressure caused by the flow f1 of the first fluid is reduced, and the second fluid L2 can be easily cut. The droplet D can be produced efficiently.

  The flow rate of the second fluid L2 is desirably 0.001 to 10 times the flow rate of the first fluid L1.

  By setting the flow rate of the second fluid L2 to 0.001 times or more of the flow rate of the first fluid L1, the discharged second fluid L2 is constant toward the center of the flow path while maintaining its shape. You can go the distance. Accordingly, since the discharged second fluid L2 is subjected to pressure due to the flow of the first fluid at a position where the flow velocity is higher, the discharged second fluid can be easily cut, and the droplet is efficiently produced. be able to.

  By setting the flow rate of the second fluid L2 to 10 times or less than the flow rate of the first fluid L1, the discharged second fluid L2 reaches the inner wall of the flow channel facing the opening while maintaining its shape. Can be prevented. Therefore, the discharged second fluid can receive pressure due to the flow of the first fluid L1, and can be cut by this pressure to produce the droplet D.

  The opening 104a of the fine hole is arranged at a position separated from the bottom surface of the first recess and the one surface of the second substrate (the overlapping surface with the first substrate 101) 105a. It consists of only one substrate 101. That is, a step d is provided between the inner side surface 104b in the opening portion of the fine hole, which is located on the first surface 101a side of the first substrate, and the first surface 105a of the second substrate.

  This step d is the upper limit distance that the fluid discharged from the opening 104a of the fine hole has an influence from the one surface 105a of the second substrate, that is, the wetting spread of the fluid to the one surface 105a of the second substrate. It is desirable that the distance is larger than the upper limit of the distance that is possible.

  As described above, according to the configuration of the base according to the first embodiment, the discharged second fluid does not spread on the overlapping surface of the second substrate and the bottom surface of the first recess. Therefore, the pressure of the first fluid acts efficiently on the discharged second fluid, and the second fluid can be cut stably and a droplet can be formed.

  Moreover, it can prevent that a droplet is formed larger than a desired size with the deformation | transformation of the 2nd fluid by wet spreading. Therefore, a minute droplet can be manufactured efficiently and stably.

  In addition, it is desirable that at least a part of the opening 104a of the fine hole is arranged in a central region in the depth direction of the first recess 102, that is, a position overlapping the central portion of the flow path of the first fluid L1.

  With such a configuration, in the flow path of the first fluid L1, the farther from the wall surface of the flow path constituted by the side surface 102b and the bottom surface 102c of the first recess and the overlapping surface 105a of the second base material, The influence of friction with the wall surface of the one fluid L1 is reduced, and the fluid can flow faster. That is, the flow rate of the first fluid L1 is maximized at the center in the flow path.

  Therefore, at least a part of the second fluid L2 discharged from the opening enters the center of the flow path, and receives a large pressure from the portion of the first fluid L1 with the maximum flow velocity. As a result, the discharged second fluid L2 is easily cut, and a large amount of droplets D can be manufactured at high speed.

[Manufacturing method of substrate]
A method of manufacturing the base body 100 shown in FIG. 2 will be described with reference to FIGS. FIG. 3 shows a flow of the manufacturing process of the base body 100. FIG. 4 is a view showing a cross-section of the main part of the object to be processed in the manufacturing process of the substrate in order of the manufacturing process. The base body 100 can be manufactured through the six steps (first to sixth steps) shown in FIG.

  First, as shown in FIG. 4A, as a first step (step P1), a region of the first substrate 101 in which fine holes are formed is condensed and irradiated with laser light L, and the first substrate 101 The structural modification portion (modified portion) 101c is formed by scanning the focal point Lf in the direction S parallel to the one main surface 101a.

  The first process is performed through two steps. That is, as a first step, adjustment is performed so that the intensity becomes a desired magnitude with respect to linearly polarized laser light (linearly polarized laser light) emitted from the light source and having a pulse width of the order of picoseconds or less.

  Specifically, the adjustment is performed so that the intensity at the focal point Lf of the laser beam L focused on the first substrate 101 is larger than the processing lower limit threshold value. The processing lower limit threshold here is defined as a lower limit value at which a reformed portion can be formed at a focused point when linearly polarized laser light is focused and irradiated on the vicinity of the surface of the first substrate 101. Is.

  Further, the intensity of the laser beam L is a distance from one main surface (one surface) 101a of the substrate to the position where the modified portion is formed in step P1, so that the modified portion to be formed can be removed by etching. Adjust accordingly.

  Next, as a second step, the laser beam L generated in the light source is condensed and irradiated to the inside of the first substrate 101 by passing through the lens, etc., along the region where the modified portion (micropore) is formed. Then, the focused focus Lf is scanned.

  By undergoing the above two steps, the modified portion 101c can be formed in the first substrate 101 in the region scanned by condensing and irradiating the laser beam L and in the vicinity thereof. The formed modified portion 101c is weakened in etching resistance by the focused irradiation of the laser beam L.

  Actually, when the laser beam L is scanned, the first modified portion is formed in the scanned region, that is, the region to be modified, and the first modified portion is formed in the region near the scanned region, that is, the region that is not to be modified. Two reforming sections are formed. However, the etching resistance of the first modified portion is weaker than the etching resistance of the second modified portion.

  Next, as a second step, as shown in FIG. 4B, patterning for a micron order flow path (micro flow path) is performed by photolithography, so that the first recess 102 of the first substrate 101, the second A portion excluding the portion where the recess 103 is provided is masked using the resist R.

  Subsequently, as a third step (step P2), as shown in FIG. 4C, the portions where the first recess 102 and the second recess 103 are not masked are removed by dry etching. Thereby, the 1st recessed part 102 and the 2nd recessed part 103 are formed in one main surface 101a of a 1st board | substrate, and the modified part 101c is exposed in the inner surface of each recessed part.

  Subsequently, as a fourth step, the resist R used for the mask is peeled off from the first substrate 101 and removed.

  Next, as a fifth process (process P3), as shown in FIG. 4D, the modified portion 101c is selectively etched to form fine holes in the first substrate 101.

  The etching treatment may be performed using either a dry etching method or a wet etching method, but it is preferable to use a highly isotropic wet etching method in order to form a microscopic hole having a three-dimensional structure. Therefore, the etching process in step P5 in the present embodiment is performed by applying a wet etching method.

  Specifically, the to-be-processed object which passed through the 4th process is immersed in the etching liquid accommodated in the specific container. Then, the entire modified portion 101c formed inside the first substrate 101 is soaked with an etching solution, and the removal of the modified portion 101c proceeds.

  The etching process of the fifth step uses the phenomenon that the modified portion 101c is etched faster in the first substrate 101 than the portion that is not laser-irradiated and structurally modified, As a result, fine holes corresponding to the shape of the modified portion 101c can be formed.

  As an etchant, for example, an alkaline solution such as hydrofluoric acid (HF) or potassium hydroxide (KOH), or a hydrofluoric acid mixed acid solution obtained by adding an appropriate amount of nitric acid or the like to hydrofluoric acid can be used. Other chemicals may be used depending on the material to be configured.

  In particular, an alkaline solution (KOH solution) containing potassium hydroxide as a main component has high selectivity as an etching solution and has an excellent function of selectively removing only the modified portion. Therefore, for example, when the KOH solution forms a space that forms micropores by removing the plurality of first reforming portions formed close to each other, the first modification is performed so that the spaces are not connected to each other. This is effective when it is required to selectively remove only the mass part.

  After the etching process in the fifth step, a microhole 104 is formed at a desired position inside the first substrate 101. Note that the laser light used in the process P1 can be modified by scanning a minute region smaller than a micron order. Therefore, it is possible to form the micropore 104 having a minimum dimension in the nano order (an order of several tens [nm] to 100 [nm]). The size of the formed micropore 104 is, for example, a minor axis of about 20 [nm] to 200 [nm] and a major axis of about 0.2 [μm] to 5 [μm], and the cross-section of the through-hole is substantially elliptical. It becomes. Depending on the state of the etching process, the cross section may have a shape close to a rectangle.

  By adjusting the etching processing time, it is possible to adjust the volume ratio between the portion of the modified portion 101c that is removed and becomes the microhole 104 and the portion that is not removed and remains as the modified portion. For example, by increasing the etching processing time, the minor axis can be extended to about 1 [μm] to 2 [μm].

  Next, as a sixth step (step P4), as shown in FIG. 4E, at least the first concave portion 102 and the second concave portion 103 are covered on one surface 101a of the first substrate that has undergone the step P5. The second substrate 105 is bonded (cap bonding). The base body 100 shown in FIG. 2 is obtained through the first to sixth steps.

  According to the above-described substrate manufacturing method, a modified portion having a size of micro order or less can be formed inside the substrate by irradiation with laser light. Therefore, by removing this modified portion by etching, a minute flow path can be formed inside the substrate.

  Hereinafter, the present invention will be described more specifically using Examples 1 to 3 corresponding to the first embodiment. However, examples to which the present invention is applicable are not limited to Examples 1 to 3. Absent.

[Example 1]
As Example 1, the flow velocity distribution of the first fluid L1 in the flow path was examined. The result is demonstrated using FIG. 5 (a)-(c). FIG. 5A is a perspective view of the internal space (the flow path of the first fluid L1) S1 that is surrounded by the second substrate 105 and the first recess 102 shown in FIGS. 2A and 2B. It is. The z axis is taken in the flow direction f1 when the first fluid L1 is caused to flow in the internal space S1, and the x axis and the y axis perpendicular to each other are taken in a plane perpendicular thereto.

  FIG. 5B is a graph showing, by contour lines, the z component of the flow velocity of the first fluid L1 in the cross section C perpendicular to the flowing direction f1 of the first fluid L1 in FIG. The cross section C was a substantially square having a side of about 10 [μm]. The horizontal axis of the graph indicates the position of the cross section C in the x-axis direction, and the vertical axis of the graph indicates the position of the cross section C in the y-axis direction. The graph of FIG. 5B shows the result that the flow velocity (the z component) of the first fluid L1 is the largest in the cross section C and decreases as the distance from the central portion increases.

  FIG. 5C is a graph showing the flow velocity distribution of the first fluid L1 at positions a1, a2, and a3 in the y-axis direction of the graph of FIG. 5B. The horizontal axis of the graph indicates the position in the x direction in the cross section C, and the vertical axis of the graph indicates the z component of the flow velocity of the first fluid L1. The solid line, the alternate long and short dash line, and the alternate long and two short dashes line shown in the graph of FIG. 5C indicate the flow velocity distribution of the first fluid L1 at the positions a1, a2, and a3, respectively. The graph of FIG.5 (c) has shown the result that the flow velocity of the 1st fluid L1 becomes large in the y direction (depth direction) of the cross section C, the position close | similar to the center part of a flow path.

  As shown in the graphs of FIGS. 5B and 5C, the flow path of the first fluid L1 includes the side surface 102b and the bottom surface 102c of the first recess and the overlapping surface 105a of the second base material. The farther from the wall surface of the flow path, the smaller the influence of friction with the wall surface of the first fluid L1, and the faster it can flow. That is, the flow rate of the first fluid L1 is maximized at the center in the flow path.

  Therefore, it is desirable that at least a part of the opening 104a of the fine hole is arranged at a position overlapping the central region in the depth direction of the first recess 102, that is, the center of the flow path of the first fluid L1. With such a configuration, at least a part of the second fluid L2 discharged from the opening enters the central portion of the flow path, and receives a large pressure from the portion of the first fluid L1 having the maximum flow velocity. As a result, the discharged second fluid L2 is easily cut, and a large amount of droplets D can be produced at high speed.

[Example 2]
As Example 2, FIG. 6 shows the result of examining the size of a droplet manufactured using the substrate 100 according to the first embodiment. FIG. 6 is a graph summarizing the numbers produced for each droplet diameter. The horizontal axis of the graph indicates the diameter of the produced droplets, and the vertical axis of the graph indicates the number of produced droplets.

As a result of estimation from the distribution of the graph, the diameters of the produced droplets averaged 1.1 [μm] (standard deviation 260 [nm]). This was found to be a size corresponding to 14 [fL] in terms of volume.
The diameter of the droplet obtained by the prior art shown in FIG. 7 was about 10 [μm] (1 [fL]), whereas the diameter of the droplet obtained by Example 2 of the present invention was It was found to be about 1/10.

[Example 3]
As Example 3, FIG. 9 shows the result of observing an enzyme reaction using a droplet produced using the substrate 100 according to the first embodiment. In the produced droplet D, one enzyme molecule (β-galactosidase) is confined at a probability, and fluorecein-Di-Galactopyranoside (FDG) is used as a substrate for β-galactosidase. FIG. 9A is a photograph obtained by observing the droplet D produced in the fine channel C in bright field using an optical microscope. FIG. 9B is a photograph obtained by fluorescence observation of the droplet D produced in the fine channel C in the same place as FIG. 9A. Since the produced droplet D showed a fluorescence reaction, it became clear that a minute space of about 1 μm in the droplet D could be used as an enzyme reaction field.

  The present invention can be widely applied as an apparatus for manufacturing a droplet of a desired size in a large amount and at high speed. In addition, it can be widely used in the fields of biotechnology and chemistry, such as detection of chemical / biological reactions in droplets.

101 ... first substrate, 101a, 105a ... one side, 102 ... first recess,
103 ... second recess, 104 ... micropore, 105 ... second substrate,
L1 ... first fluid, L2 ... second fluid, d3 ... step.

Claims (4)

A first substrate;
A first recess formed on one surface of the first substrate and forming a flow path of a first fluid;
A second recess formed on one surface of the first substrate and forming a flow path for the second fluid;
A second substrate overlaid on one surface of the first substrate so that the first recess and the second recess are covered;
In the first substrate, an internal space surrounded by the second substrate and the first recess and an internal space surrounded by the second substrate and the second recess are communicated, and from one internal space A fine hole capable of flowing the first fluid or the second fluid toward the other internal space, and
A base is provided, wherein a step is provided between an inner surface of the opening of the micropore and one surface of the second substrate which forms an overlapping surface with one surface of the first substrate.   2. The substrate according to claim 1, wherein at least a part of the opening of the fine hole is disposed at a position overlapping a central region in a depth direction of the first recess.   3. The substrate according to claim 1, wherein a minor axis of the micropore is 20 nm or more and 10 μm or less.   4. The substrate according to claim 1, wherein the flow rate of the second fluid is 0.001 to 10 times the flow rate of the first fluid.