Flow passage device and gene extraction device

Abstract

To provide a flow passage device capable of sequentially flowing down a plurality of liquids and switching a flow passage with an inexpensive device while reducing the loss of a sample or the like, and a device capable of inexpensively and easily extracting a gene by combining them.SOLUTION: In order to sequentially supply liquids, in a liquid feeding flow passage 20, an upstream side flow passage is connected to timing chambers 1, 2, 3 from a peripheral side of a substrate toward a rotation center RC, and a downstream side flow passage includes siphon structure parts 22, 32 that branch in the vicinity of a part where the upstream side flow passage is connected to the timing chambers and meanders toward the rotation center on the way to a waste liquid tank 50. In order to switch the flow passage, a terminal side flow passage 70 is branched, a first flow passage resistance part 71 is provided on one side, an air supply flow passage 80 connected to the waste liquid tank is provided on one side obtained by branching the downstream side flow passage, and a second flow passage resistance part 81 is provided near the branch point. A gene extraction device is configured by combining the above.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a flow channel device and a gene extraction device that utilize an external force generated by the rotation of a substrate. [Background technology]

[0002] Ultra-small flow channel devices using microchips, such as μ-TAS (Micro Total Analysis System), have been developed to sequentially supply multiple liquids (solutions) in biological material analysis, chemical reactions, and other applications. A microchannel with a valve structure has been developed in which a first upstream container is provided with a gas inlet channel, a second upstream container is provided with no gas inlet channel, the first upstream container and the second upstream container are connected by a flow channel, and both the first upstream container and the second upstream container are connected to a downstream container (see Patent Document 1). This technology has a valve structure designed so that when gas is introduced into the first upstream container, the liquid stored in the first upstream container first flows down to the downstream container. When the introduced gas reaches the flow channel connected to the second upstream container, the gas is introduced into the second upstream container, causing the liquid stored in the second upstream container to begin flowing down.

[0003] However, because there was a risk of leakage of the liquid in the first upstream container moving to the second upstream container due to the flow path for moving the introduced gas from the first upstream container to the second upstream container, a technology has been developed in which the liquid flows sequentially through separate flow paths that do not connect the two containers (see Patent Document 2). This technology causes the liquid to flow sequentially down to a single downstream container (chamber) through two types of flow paths that are configured independently, and each flow path is equipped with a reservoir (having an exhaust part (vent)) and a siphon structure with a bypass flow path connected to its output port (liquid outlet), so that after an appropriate amount of liquid is stored in the reservoir, the siphon structure allows the liquid to flow instantaneously down to the downstream container (chamber).

[0004] On the other hand, a flow channel switching control method has also been developed to separate multiple liquids into different downstream containers after flowing them. The flow channel switching methods in microfluidic devices that use centrifugal force for liquid transfer can be broadly divided into active control methods and passive control methods.

[0005] As an active control method, there is a method in which paraffin embedded in one of the flow paths is heated and melted beforehand, and the flow path is switched to the other flow path (a flow path with a wider flow path width) (see Non-Patent Document 1). In this case, an external device such as a heater is required. There is a method for switching the flow by applying air pressure to a chamber into which the liquid flows and reversing the direction of rotation (see Non-Patent Document 2). In this case, an external device such as an air pressure device is required, and control of the direction of rotation is also necessary. Furthermore, there is a method for switching the flow path by blocking the flow path with a plunger (see Non-Patent Document 3). In this case, an external device such as a plunger is required. As such, in the case of active control methods, various external devices are required, and the cost of the device is high because it is also necessary to simultaneously control the rotation, etc.

[0006] The passive control method was configured to switch the flow of liquid into two reservoirs by reversing the direction of rotation (controlling the direction in which the Coriolis force acts) (see Non-Patent Documents 4 and 5). With this method, when dynamically switching the direction of rotation (reversing the direction of rotation), it was not possible to completely block the flow of liquid in the flow channel while the rotation was slowing down and stopping, which inevitably led to the liquid continuing to infiltrate into the branch flow channel, making it difficult to reliably switch the flow channel. In addition, the need to control the direction of rotation and the rotation speed also increased the cost of the device.

[0007] On the other hand, gene extraction devices (gene extraction kits) that use multiple liquids (solutions) sequentially are widely used. Currently used gene extraction kits include a method using a spin column (see Patent Document 3) and a method using magnetic beads (see Patent Document 4). However, the method using a spin column has a problem in that the pores of the column (silica or glass fiber) for adsorbing genes (DNA, RNA, etc.) are small, requiring a long time for liquid to pass through, making it unsuitable for rapid gene extraction. On the other hand, the method using magnetic beads has the advantage of being able to extract highly pure genes in a short time, but has the problem that the handling of the magnetic beads is complicated, requiring skill from the operator, and is not suitable for automation. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-088211 [Patent Document 2] JP 2017-075807 (Patent No. 6855003) [Patent Document 3] Special Publication No. 2013-519396 [Patent Document 4] Special Publication No. 2019-517774 [Patent Document 5] International Publication WO2023 / 120648 [Non-patent literature]

[0009] [Non-Patent Document 1] Y.Wang et al., Microfludics Nanofluiddics, 23(2019)112 [Non-patent document 2] MCRKong and EDSalin, Anal.Chem., 83(2011)1148-1151 [Non-patent document 3] J. Xiang et al., Sens. Actuators B, 259(2018)325-331 [Non-patent document 4] J.Kim et al., Sens. Actuators B, 128(2008)613-621 [Non-Patent Document 5] A. Kazemzadeh et al., Sens. Actuators B, 204(2014)149-158 Summary of the Invention [Problem to be solved by the invention]

[0010] As mentioned above, in various devices that use external forces such as centrifugal force to cause a liquid (solution) to flow, a siphon structure can be provided to prevent liquid leakage when multiple liquids (solutions) are supplied sequentially. However, when a liquid stored in a reservoir starts to flow, the liquid inside the reservoir instantly flows out. This causes ambient air to flow into the reservoir through the exhaust (vent), preventing subsequent liquid from being supplied to the reservoir. In other words, unused liquid (solution) remains upstream of the reservoir. While this is not a problem in the sense that the purpose is achieved as long as the appropriate amount of liquid (solution) flows down to the supply destination, if the liquid (solution) being used is a rare sample or an expensive reagent, the sample or reagent remaining in the device is discarded, resulting in significant waste.

[0011] On the other hand, when it comes to switching the flow path to separate the liquid (solution) into different downstream containers, whether an active control system or a passive control system is adopted, the cost of the device is high. Furthermore, even when a gene extraction device is produced using the above-mentioned conventional technologies, it leads to sample loss and an increase in the cost of the device.

[0012] The present invention has been made in consideration of the above points, and its purpose is to provide a flow path device that enables sequential flow of multiple liquids (solutions) and flow path switching using an inexpensive device while reducing loss of samples, etc., and a device that can extract genes inexpensively and easily by combining these. [Means for solving the problem]

[0013] Therefore, as a result of intensive research, the inventors of the present application have discovered that by utilizing the basic principles of the invention developed by the inventors of the present application (Patent Application No. 2023-040339), it is possible to construct a flow path device that prevents loss of samples, etc., and that by using the basic principles of the dispensing structure developed by the inventors of the present application (see Patent Document 5), it is possible to enable flow path switching at the required timing. They have also discovered that by combining these, it is possible to realize a gene extraction device.

[0014] That is, a first invention relating to a flow path device is a flow path device provided on a substrate that can rotate about a predetermined center of rotation, and composed of flow paths that can deliver liquid based on external forces generated by the rotation of the substrate, the flow path device comprising: an injection reservoir provided near the center of rotation for storing the liquid to be delivered; a waste tank provided away from the center of rotation for finally storing the delivered liquid; a timing chamber for adjusting the timing of delivery from the injection reservoir to the waste tank; an upstream flow path that delivers liquid from the injection reservoir to the timing chamber; and a downstream flow path that delivers liquid from the timing chamber to the waste tank, wherein the upstream flow path is connected to the timing chamber from the periphery of the substrate toward the center of rotation, and the downstream flow path has a siphon structure that branches near the part where the upstream flow path connects to the timing chamber and snakes toward the center of rotation on the way to the waste tank, and the timing chamber has an exhaust section connected to the center of rotation.

[0015] According to the above configuration, since the siphon structure is provided midway between the timing chamber and the waste tank, when the amount of liquid stored in the timing chamber increases and the siphon structure functions to start liquid transfer, the liquid in the timing chamber and the liquid flowing down the upstream flow path flow downward toward the siphon structure. As a result, even after the liquid in the timing chamber starts to flow downward, the liquid flowing down from the injection reservoir via the upstream flow path can continue to flow downward, making it possible to reduce residue of sample, reagent, etc.

[0016] It is assumed that the timing chamber is provided with an exhaust section, and when liquid flows into the timing chamber, the air inside is expelled. On the other hand, when the liquid starts to flow down after being stored in the timing chamber, outside air is drawn in through the exhaust section. As mentioned above, when the siphon structure functions, the fluid in the timing chamber starts to flow down, but the liquid in the upstream flow path also flows down at the same time, so the decrease in the liquid in the timing chamber is gradual, and the flow of liquid in the upstream flow path is rarely interrupted by the drawn-in outside air.

[0017] A second invention relating to a flow path device is the first invention, wherein the upstream flow path is configured to have a long, meandering flow path length, and is provided with an in-flow path reservoir that adjusts the time it takes for liquid to be sent to the timing chamber by gradually sending liquid from the center of rotation toward the periphery of the substrate as the substrate rotates.

[0018] The above configuration not only adjusts the timing of liquid delivery using the timing chamber, but also enables a time delay corresponding to the length of the upstream flow channel when the liquid flows down the upstream flow channel. This allows for a long delay in liquid delivery that cannot be adjusted using the timing chamber alone, making it possible to appropriately adjust the timing when multiple liquids are sequentially delivered. The in-channel reservoir can be configured by forming multiple long flow channels in the rotation direction (radial direction) of the substrate, and by using a bypass flow channel that connects these channels in sequence from the rotation center. By gradually delivering liquid through this bypass flow channel from the rotation center to the periphery of the substrate, the liquid can be temporarily stored within the bypass flow channel and the gradual flow down delays the liquid delivery. While a bypass flow channel is a typical example of an in-channel reservoir, the concept is broad and includes not only bypass flow channels but also any other configuration that temporarily stores liquid and delays its flow down.

[0019] A third invention relating to a flow path device is the second invention, wherein the timing chambers are arranged side by side at an equal distance from the center of rotation, and the timing chambers are divided into upstream chambers connected to the upstream flow path and next-order chambers connected to intermediate flow paths that branch off near where the upstream flow path connects to the upstream chamber, and the downstream flow path branches off near where the intermediate flow path connects to the next-order chamber located most downstream.

[0020] According to the above configuration, multiple timing chambers are disposed at equal distances from the center of rotation, and an upstream flow path connected to the first-order timing chamber (first chamber) located most upstream branches off to form an intermediate flow path. This intermediate flow path connects to the next-order timing chamber (next-order chamber) from the upstream side, branches off again, and can then connect to the next-order timing chamber. The downstream flow path branches off from the intermediate flow path connected to the most downstream timing chamber (final chamber) and is connected to a siphon structure. For the siphon structure to function (start flowing to the waste tank), all of the multiple timing chambers arranged side by side must store an appropriate amount of liquid, and the flow to the waste tank can be delayed by the time required for this. Since this invention is a configuration associated with the second invention, it is possible to adjust the delay in liquid supply time in addition to the time it takes for the liquid to flow down the upstream flow path, which is configured as a long, serpentine flow path.

[0021] A fourth invention relating to a flow path device is a flow path device provided on a substrate that can rotate around a predetermined rotation center, and configured with flow paths that can transfer liquids based on an external force generated by the rotation of the substrate, for transferring a plurality of liquids to the same reaction chamber sequentially with a time difference while passing through different flow paths, the flow path device comprising: a plurality of injection reservoirs provided on a side closer to the rotation center and each storing a plurality of liquids to be transferred; at least one waste liquid tank provided on a side farther from the rotation center and finally storing the transferred liquids; a single reaction chamber provided between the plurality of injection reservoirs and the waste liquid tank; and a plurality of liquid transfer flow paths that individually transfer liquids between the plurality of injection reservoirs and the reaction chamber, a timing chamber for adjusting the timing of liquid delivery between the injection reservoir and the timing chamber; an upstream flow path for delivering liquid from the injection reservoir to the timing chamber; a downstream flow path for delivering liquid from the timing chamber to the reaction chamber; and a terminal flow path for delivering liquid from the reaction chamber to the waste liquid tank, wherein the upstream flow path is connected to the timing chamber from the periphery of the substrate toward the center of rotation, and the downstream flow path branches off near the part where the upstream flow path connects to the timing chamber and has a siphon structure that snakes toward the center of rotation on the way to the waste liquid tank, and the timing chamber, reaction chamber, and waste liquid tank all have exhaust parts connected to the side of the center of rotation.

[0022] According to the above configuration, liquid can be supplied from multiple injection reservoirs to a single reaction chamber via individual liquid supply paths, and the timing of supplying the liquid stored in the multiple injection reservoirs can be changed for each liquid supply path, thereby enabling sequential supply of liquid to a single reaction chamber and sequential reaction between the liquid and the reaction target placed in the reaction chamber.

[0023] A fifth invention related to a flow path device is the fourth invention, wherein the terminal side flow path is branched, one branch is connected to the waste liquid tank from the periphery side of the substrate toward the rotation center, and the other branch is connected to a recovery tank via a first internal flow path resistance portion; the downstream side flow path is branched upstream of connection to the reaction chamber, one branch is connected to the reaction chamber, and the other branch is connected via a second internal flow path resistance portion to an air supply flow path for connecting the waste liquid tank to an exhaust portion, and the exhaust portion of the waste liquid tank is connected via the air supply flow path and the downstream side flow path; the breakthrough pressure of the first internal flow path resistance portion is configured to be greater than the flow path resistance when the liquid to be drained is sent to the waste liquid tank and smaller than the hydraulic head pressure of the liquid flowing out of the reaction chamber; and the breakthrough pressure of the second internal flow path resistance portion is configured to be greater than the hydraulic head pressure acting on the second internal flow path resistance portion.

[0024] According to the above configuration, a specific liquid feed flow path provided in any of the multiple liquid feed flow paths is configured with a timing chamber and an upstream flow path and a downstream flow path connected to the timing chamber, so that liquid is supplied to the reaction chamber with a delay from liquid flowing down the other liquid feed flow paths. At this time, the liquid passing through the reaction chamber flows down along the terminal flow path, but it is possible to break the resistance portion in the first flow path of the other branched path (to allow liquid to pass through exceeding the resistance pressure of the resistance portion in the flow path) so that the liquid passing through the liquid feed flow path that delays the liquid supply begins to flow into the other branched path that is branched to the terminal flow path at the timing when the liquid passes through the reaction chamber.

[0025] Specifically, the breakdown pressure of the first flow path resistance (the critical pressure until breakdown) is configured to be greater than the flow path resistance when the liquid to be drained is sent to the waste tank. Therefore, the liquid flowing down to the waste tank does not flow down the branch flow path (the other of the branched terminal flow paths) toward the collection tank. Furthermore, the breakdown pressure is configured to be smaller than the hydraulic head pressure of the liquid flowing out of the reaction chamber. Therefore, the first flow path resistance breaks down in response to the hydraulic head pressure acting when the flow down to the waste tank is stopped, allowing the liquid to flow into the collection tank. Meanwhile, the downstream flow path branches upstream of the connection to the reaction chamber, and the other branch is connected to an air supply flow path for exhausting air from the waste tank. When the liquid flows down the other branch, internal air is trapped between the waste chamber and the other branch flow path connected to it. This trapping of internal air inhibits the fluidity of the liquid already flowing into the waste chamber, thereby stopping the liquid from flowing down from the reaction chamber. Since the breakdown pressure of the second resistance section interposed in the other branch of the downstream flow path is configured to be greater than the hydraulic head pressure acting on the resistance section, even if hydraulic head pressure acts at the position where the second resistance section is located when the liquid flows down the downstream flow path, the second resistance section does not break, preventing the liquid that has flowed down into the waste tank from flowing back toward the reaction chamber. Therefore, once the first resistance section breaks and the liquid begins to flow into the collection tank, the inflow state is maintained, preventing the liquid in the waste tank from being mixed in.

[0026] A sixth invention relating to a flow path device is the fifth invention, wherein the upstream flow path is configured to have a long, serpentine flow path length, and is provided with an in-flow path reservoir that adjusts the time it takes for liquid to be sent to the timing chamber by gradually sending liquid from the center of rotation toward the periphery of the substrate as the substrate rotates.

[0027] According to the above configuration, as in the second aspect of the present invention, in the liquid delivery flow path for delaying the timing of liquid delivery, it is possible to delay the time by the amount that includes the time it takes to pass through the timing chamber and the upstream flow path.

[0028] A seventh invention relating to a flow path device is the sixth invention, wherein the timing chambers are arranged side by side at an equal distance from the center of rotation, and the timing chambers are divided into upstream chambers connected to the upstream flow path and next-order chambers connected to intermediate flow paths that branch off near where the upstream flow path connects to the upstream chamber, and the downstream flow path branches off near where the intermediate flow path connects to the next-order chamber located most downstream.

[0029] According to the above configuration, the liquid delivery start time can be delayed until the multiple timing chambers are filled with liquid, as in the case of the third invention. Note that, since the present invention is a configuration accompanying the sixth invention, it is possible to adjust the delay in the liquid supply time in addition to the time it takes for the liquid to flow down the upstream flow path, which is configured as a long, meandering flow path.

[0030] The eighth invention relating to a flow channel device is any of the first to seventh inventions, in which each flow channel for liquid transport is a microchannel. With this configuration, the flow channels excluding chambers such as the timing chamber and the reaction chamber are configured to be fine, so the flow of liquid can be easily controlled by the pressure difference acting on the liquid. Furthermore, in biological analysis, it becomes possible to cause reactions using small amounts of sample, reagent, etc. in testing devices using microchips such as μ-TAS.

[0031] The present invention relating to a gene extraction device uses the flow path device described in the seventh invention relating to the flow path device, and comprises three injection reservoirs, three types of liquid sending flow paths connected to the three injection reservoirs, a single reaction chamber, one waste liquid tank, one recovery tank, and an adsorbent substance that is installed in the reaction chamber and specifically adsorbs nucleic acids, wherein the first injection reservoir stores a sample solution in which the nucleic acids have been eluted from an object to be tested, the second injection reservoir stores a washing liquid that washes away substances other than the nucleic acids, and the third injection reservoir stores an elution liquid that elutes the nucleic acids. The first liquid supply flow path is connected to the first injection reservoir and is connected to the reaction chamber without having the timing chamber; the second liquid supply flow path is connected to the second injection reservoir and is equipped with an in-flow path reservoir and one timing chamber; and the third liquid supply flow path is connected to the third injection reservoir and is equipped with an in-flow path reservoir and two or more timing chambers, and the downstream flow path constituting the third liquid supply flow path is configured to branch near a portion where the intermediate flow path constituting the third liquid supply flow path is connected to the timing chamber located most downstream.

[0032] The above configuration essentially constitutes a device using a spin column. However, because external forces such as centrifugal force can be applied by rotating the substrate, liquid can be passed through a column (silica or glass fiber) for adsorbing nucleic acids (deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) or both) in a short time. Furthermore, because the flow path device described in the seventh invention relating to a flow path device is used, the liquid flowing down from the third injection reservoir in the final stage can be switched and sent to a collection tank, allowing only the eluate containing the nucleic acids (DNA and RNA) obtained by the specified processing to be collected in the collection tank. Note that a gene extraction device is a device for extracting nucleic acids, not for extracting genes themselves. However, since extraction of nucleic acids such as DNA can be used to extract genes by analyzing their base sequences, the term "gene extraction device" is used as a synonym. [Effects of the Invention]

[0033] According to the present invention relating to the flow path device, it is possible to suppress the residual liquid in the flow path (particularly in the upstream flow path) for delaying the timing of liquid transfer, which has the effect of reducing the loss of sample, etc. Furthermore, since it is possible to sequentially flow multiple liquids and easily switch flow paths for liquids that have passed through the reaction chamber, it is possible to reduce the cost of devices that use multiple liquids.

[0034] On the other hand, according to the present invention relating to the gene extraction device, by utilizing the above-mentioned flow channel device, after nucleic acids (DNA and RNA) are eluted from the test subject, only the nucleic acids can be separated and purified to a high degree of purity and recovered within the same device, making it possible to extract nucleic acids extremely easily and, since the operation involves only rotating the substrate at a predetermined rotation speed, the device for nucleic acid extraction can be made inexpensive. Furthermore, by making the device for nucleic acid extraction inexpensive, the entire device for extracting the gene to be tested from nucleic acid can also be made inexpensive. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 1 is an explanatory diagram showing the overall structure of a flow channel device that can be used as a gene extraction device. [Figure 2] 1A and 1B are explanatory diagrams showing an embodiment of a flow path device that allows sequential liquid supply. [Figure 3] 10A and 10B are explanatory diagrams showing the operation of an embodiment of a flow path device that allows sequential liquid supply. [Figure 4] 10A and 10B are explanatory diagrams showing the operation of an embodiment of a flow path device that allows sequential liquid supply. [Figure 5] 10A and 10B are explanatory diagrams showing modified examples of a flow path device that allows sequential liquid supply. [Figure 6] 1A and 1B are explanatory diagrams illustrating an embodiment of a flow path device capable of switching flow paths. [Figure 7] 10A and 10B are explanatory diagrams showing an operation mode of a flow path device capable of switching flow paths. [Figure 8] 10A and 10B are explanatory diagrams showing an operation mode of a flow path device capable of switching flow paths. [Figure 9] FIG. 10 is an explanatory diagram showing the conditions for the breakdown pressure in the first flow path resistance portion. [Figure 10] FIG. 10 is an explanatory diagram showing the conditions for the breakdown pressure in the first flow path resistance portion. [Figure 11] FIG. 10 is an explanatory diagram showing the conditions for the breakdown pressure in the second flow path resistance portion. [Figure 12] FIG. 1 is an explanatory diagram showing an embodiment of a gene extraction device. DETAILED DESCRIPTION OF THE INVENTION

[0036] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. <Overall structure of the flow path device> First, the overall structure of the flow channel device (which can be used as a gene extraction device) including all elements is shown in Figure 1. In other words, the device structure includes both a flow channel structure for sequential liquid flow and the overall structure of a flow channel structure device that can switch flow channels.

[0037] As shown in Figure 1, the overall structure of the flow channel device is formed on a substrate (not shown in the figure) that rotates around the center of rotation RC, and external forces such as centrifugal force and Coriolis force obtained by the rotation are used for the liquid flowing down in each flow channel. Therefore, basically, the liquid flows down from a position close to the center of rotation RC to the periphery. In addition, each flow channel has a cross-sectional area of ​​0.02 mm 2 Based on a microchannel of 0.1mm x 0.2mm (rectangular channel) or less, the substrate surface is grooved, and the surface is blocked to form a closed channel.

[0038] This overall structure is divided into three types of liquid transfer flow paths 10, 20, and 30, and liquid flows down to a waste liquid tank 50 or a recovery tank 60 via a single reaction chamber 40. Note that if only sequential flow is to be performed, the reaction chamber 40 may be configured as the final tank (waste liquid tank).

[0039] The first liquid supply flow path 10 allows the first liquid L1 stored in the first inflow reservoir 11 to flow down, the second liquid supply flow path 20 allows the second liquid L2 from the second inflow reservoir 21 to flow down, and the third liquid supply flow path 30 allows the third liquid L3 from the third inflow reservoir 31 to flow down. These liquid supply flow paths 10, 20, and 30 are configured with different flow path lengths, and by interposing timing chambers 1, 2, and 3 in the flow paths, the timing of the flow down (liquid supply) to a single reaction chamber 40 can be adjusted, enabling sequential liquid supply.

[0040] Each flow path is connected to an intake part IP, which supplies outside air into the flow path to allow the liquid to flow downward, and an exhaust part EP, which exhausts the air inside. While the flow paths are closed, the intake part IP and exhaust part EP have ends (shown as circles in the figure) that open to the outside. Furthermore, the exhaust parts connected to timing chambers 1, 2, 3, etc., are used to exhaust air when liquid flows into the timing chambers 1, 2, 3, but also function as intake parts when liquid flows out of the timing chambers 1, 2, 3.

[0041] The overall structure of the flow path device in FIG. 1 shows a configuration in which the liquid that has passed through the reaction chamber 40 can be switched between flowing down to the waste liquid tank 50 and flowing down to the collection tank 60. To achieve this, the terminal-side flow path 70 is branched, and one of the branches is provided with a first intra-flow path resistance portion 71. The presence of this first intra-flow path resistance portion 71 prevents the liquid from flowing down to the collection tank 60 during normal liquid transfer. To enable this flow path switching, the third liquid transfer flow path 30 is branched downstream of the timing chamber 3 (upstream of the reaction chamber 40), and one branch is connected to the reaction chamber 40, allowing the third liquid L3 to flow down to the reaction chamber 40 as intended. In contrast, the other branch is connected to the waste liquid tank 50, thereby functioning as an air transfer flow path 80 for the waste liquid tank 50. That is, while the first liquid L1 and the second liquid L2 are being sent to the reaction chamber 40, the liquids that have passed through the reaction chamber 40 flow into the waste liquid tank 50, and at this time, the internal air present inside the waste liquid tank 50 is discharged while passing through the air supply flow path 80 and joining the third air supply flow path 30. However, at the timing when the third liquid flows down into the reaction chamber 40, the third liquid L3 flows into the branched air supply flow path 80, which restricts the movement of the internal air in the waste liquid tank 50 and the air supply flow path 80. As a result, no additional flow into the waste liquid tank 50 occurs, and flow into the collection tank 60 can begin.

[0042] Furthermore, in order to prevent the third liquid L3 injected into the air supply flow path 80 from flowing down into the waste liquid tank 50, a second intra-flow path resistance portion 81 is provided in the air supply flow path 80. This second intra-flow path resistance portion 81 restricts the flow down of the third liquid, and the waste liquid that has flowed into the waste liquid tank 50 can be stored without moving. As a result of the flow into the waste liquid tank 50 being hindered, the liquid that subsequently passes through the reaction chamber 40 flows into the recovery tank 60, thereby ensuring reliable flow path switching. Details of these configurations will be described later.

[0043] <Flow path device for sequential liquid supply> Next, an embodiment of the present invention relating to a flow path device that enables sequential liquid supply will be described. Figure 2 shows the configuration of the flow path device. Note that in this figure, the connection between the injection reservoir 21 and the intake part IP is omitted, and a configuration is shown in which liquid flows directly down to the waste liquid tank 50 without using a reaction chamber, showing a state specialized for a configuration for sequential liquid supply.

[0044] 2, this embodiment is configured such that a timing chamber 1 is provided midway along a liquid delivery flow path 20, and a siphon structure 22 is provided downstream of the timing chamber 1. The section of the liquid delivery flow path 20 from the injection reservoir 21 to the timing chamber 1 is defined as an upstream flow path 23, and the section from the timing chamber 1 to the waste liquid tank 50 is defined as a downstream flow path 24.

[0045] Because the timing chamber 1 can be used as a configuration for sequential liquid supply, the upstream flow path 23 may be short. However, to adjust the time until the inflow starts, the upstream flow path 23 may be provided with a long, meandering bypass flow path 23a. This bypass flow path 23a functions as an in-flow reservoir. Here, the short flow path is primarily shown, with the bypass flow path 23a secondarily indicated by a dashed dotted line. When the bypass flow path 23a is formed, it should be configured to meander radially in both outward and return directions while gradually changing its distance from the rotation center RC. This allows for the liquid to be gradually delivered from the rotation center RC toward the periphery as the substrate (not shown) rotates. While the liquid flows down along the bypass flow path 23a, the liquid is temporarily stored within the flow path, allowing it to function as an in-flow reservoir.

[0046] Here, in this embodiment, the upstream flow path 23 is connected to the timing chamber 1 from the periphery of the substrate toward the rotation center RC (i.e., at the position farthest from the rotation center RC), and the liquid L2 flowing down along the upstream flow path 23 flows from the bottom side of the timing chamber 1 in the opposite direction to the direction in which the centrifugal force acts.

[0047] Additionally, upstream flow path 23 is configured to branch at an arbitrary position 25 near the portion where it connects to timing chamber 1, and a flow path (branched flow path) 26 branched from branch point 25 connects to timing chamber 1. Therefore, with branch point 25 as the boundary, the flow path located downstream of this becomes downstream flow path 24.

[0048] In order for branch flow 26 to flow into timing chamber 1, flow resistance and centrifugal force (hydraulic head pressure) act in the opposite direction, so the flow also branches off into downstream flow path 24 and flows downward, but when the flow resistance, etc. in downstream flow path 24 exceeds the flow resistance, etc. of branch flow path 26, the flow into timing chamber 1 begins. This is explained in detail in the aforementioned Japanese Patent Application No. 2023-040339.

[0049] Meanwhile, downstream flow path 24 is provided with siphon structure 22 midway along its section to waste liquid tank 50, which is located further downstream (closer to the periphery of the substrate). Siphon structure 22 is structured to meander toward rotation center RC near timing chamber 1, with the meandering portion closest to rotation center RC (top of the serpentine flow path) 22a located close to the end of timing chamber 1 on the rotation center RC side. Note that this location is located downstream (closer to the periphery of the substrate) of the end of timing chamber 1 on the rotation center RC side, taking into account the difference in flow path resistance. This allows Liquid L2 to pass through top of serpentine flow path 22a before timing chamber 1 is filled with Liquid L2, thereby initiating liquid transfer by the siphon effect.

[0050] When liquid L2 flows downstream from siphon structure 22 due to the siphon effect, the liquid L2 to be delivered is not limited to the liquid filled in timing chamber 1, but also includes the liquid flowing down upstream flow path 23. Therefore, exhaust part EP connected to timing chamber 1 functions to exhaust liquid L2 when filling timing chamber 1 with liquid L2, but functions as an intake part when supplying (flowing down) liquid L2. However, even when outside air is drawn in, liquid L2 is supplied to upstream flow path 23 and downstream flow path 24 in a continuous state, so that a liquid shortage due to outside air mixing between both flow paths 23, 24 does not occur.

[0051] <Operation mode> The operation of the flow path device of this embodiment will now be described. FIGS. 3 and 4 show the sequential liquid supply state according to this embodiment. Since this embodiment has the above-described configuration, as shown in FIG. 3(a), liquid L2 injected (flowing down) from injection reservoir 21 flows down along upstream flow path 23 to branch point 25, where it splits into downstream flow path 24 and branch flow path 26. The flow state at this time is determined by the ease of flow, depending on the flow path resistance acting on each liquid and external forces acting on liquid L2, such as centrifugal force (hydraulic head pressure) or Coriolis force. Furthermore, when liquid L2 flows from branch flow path 26 into timing chamber 1, surface tension acts at the inlet, causing liquid L2 to preferentially flow down downstream flow path 24. When liquid L2 flows down an appropriate length of downstream flow path 24, the pressures of both sides are balanced (see FIG. 3(a)). Then, liquid L2 starts to flow into timing chamber 1 and continues to flow down along downstream flow path 24 (see FIG. 3(b)).

[0052] When the liquid L2 flows into the timing chamber 1, the air inside the timing chamber 1 is discharged from the exhaust part EP, and the air inside the downstream flow path 24 is discharged from the exhaust part EP connected to the waste liquid tank 50 (Figure 2) at the end.

[0053] As described above, while liquid L2 is being supplied to timing chamber 1 and downstream flow path 24 (until it reaches apex 22a of siphon structure 22), the pressures in both are balanced, and both liquids flow downward so as to raise the liquid level (approach the center of rotation RC) (see FIG. 3(b)). When liquid L2 flowing downward into downstream flow path 24 passes apex 22a of siphon structure 22, a large amount of liquid L2 has flowed into timing chamber 1 (see FIG. 4(a)).

[0054] From this state, the siphon effect of siphon structure 22 is exerted, and the flow of liquid L2 downstream from siphon structure 22 is promoted, and the flow rate of liquid L2 supplied exceeds the flow rate of liquid L2 flowing down upstream flow path 23, causing liquid L2 flowing into timing chamber 1 to flow out at the same time (see FIG. 4(b)). Note that when liquid L2 flows out of timing chamber 1, air must flow in, and therefore exhaust part EP functions as an intake part, supplying outside air to timing chamber 1.

[0055] In this way, both liquid L2 that has been flowing into the timing chamber 1 and liquid L2 supplied from the injection reservoir 21 are supplied to the downstream flow path 24, and even after the liquid in the timing chamber 1 begins to flow down, liquid L2 supplied from the injection reservoir 21 continues to be used for delivery. Therefore, a liquid shortage due to outside air mixing in does not occur midway through the supply path, and liquid L2 from the injection reservoir 21 can be delivered at least until all of the liquid L2 that has flowed into the timing chamber 1 is discharged, making it possible to minimize the amount of residual reagent, etc.

[0056] <Modification> FIG. 5 shows a modified example of this embodiment. This modified example is configured to further delay the timing of the liquid L2 flowing down to the waste liquid tank 50 when the liquid L2 is supplied sequentially. As described above, the timing of the flow down is basically delayed by causing the liquid L2 to flow into one timing chamber 1 (see FIG. 2). However, as shown in FIG. 5, by providing a long bypass flow path 23a in the upstream flow path 23, the time it takes for the liquid L2 to reach the timing chamber 2 can be extended, thereby delaying the timing of the flow down. Furthermore, by arranging multiple timing chambers 2, 3 (two in the figure) side by side, the timing of the flow down can be further delayed.

[0057] When multiple timing chambers 2, 3 are provided as described above, these timing chambers 2, 3 are arranged at equal distances from the rotation center RC and flow in under the same conditions. Specifically, the upstream flow path 23 branches at the first (upstream) branch point 25a into a branch flow path 26a for introducing the liquid L2 into the first-order timing chamber 2 and an intermediate flow path 27, which is an extension of the upstream flow path 23. Similar to the upstream flow path 23, this intermediate flow path 27 branches at the next branch point 25b into a branch flow path 26b for introducing the liquid L2 into the next-order timing chamber 3 and a downstream flow path 24, and this downstream flow path 24 is configured to be provided with a siphon structure 22. A single exhaust part EP is connected to the multiple (two in the figure) timing chambers 2, 3 in a shared manner, allowing exhaust when the liquid L2 flows in and intake when the liquid L2 flows out.

[0058] With this configuration, liquid L2 that has flowed down the upstream flow path 23 (passed through the bypass flow path 23a) branches off into branch flow path 26a and intermediate flow path 27 at the first branch point 25a and continues to flow down. When the flow path resistance of intermediate flow path 27 exceeds the inflow pressure into the first-order timing chamber 2, liquid L2 begins to flow into the first-order timing chamber 2 and continues to flow down along the intermediate flow path 27. When liquid L2 reaches second branch point 25b, it again branches off into branch flow path 26b and downstream flow path 24. When the flow path resistance of downstream flow path 24 exceeds the inflow pressure into the next-order timing chamber 3, liquid L2 begins to flow into the next-order timing chamber 3. In this state, liquid L2 flows into the first-order timing chamber 2 first, but then flows into the next-order timing chamber 3 slightly later. Therefore, the flow of liquid L2 down can be delayed by using the two timing chambers 2 and 3.

[0059] Furthermore, the liquid L2 gradually flows down the downstream flow path 24 branching off at the second branch point 25b, and as the flow progresses up to the top 22a of the siphon structure portion 22, a siphon effect is exerted, as in the above-described embodiment, and the liquid L2 flows down toward the waste liquid tank 50.

[0060] In the above-described modified example, two timing chambers 2 and 3 are arranged side by side as a typical example. However, if it is desired to further delay the timing of the flow down, three or more timing chambers may be arranged side by side. In particular, when the depth of the entire flow path is approximately the same, the capacity of the timing chambers 2 and 3 is determined by their surface size. Therefore, in circumstances where it is not possible to form large timing chambers 2 and 3, the overall capacity can be increased by increasing the number of small timing chambers 2 and 3. In addition, although the length of the bypass flow path 23a is not particularly limited, the timing of the flow down may be delayed by adjusting the length (designing it longer).

[0061] <Flow path switchable device> Next, an embodiment of the present invention relating to a flow path device capable of flow path switching will be described. FIG. 6 shows the configuration of the flow path device. Note that in this figure, the connection between the injection reservoirs 11 and 31 and the intake portion IP is omitted, and the timing chamber and siphon structure for the sequential flow of the third liquid L3 are omitted. This shows a state specialized for the flow path switching structure when two types of liquids L1 and L3 are sequentially supplied (i.e., after the first liquid L1 is caused to flow from the first injection reservoir 11, the next-order liquid L3 is caused to flow from the next-order injection reservoir 31 with a delay). Furthermore, although the reaction chamber 40 is not essential for explaining only the flow path switching structure, for the convenience of explaining the provision of the flow path switching structure in the distal-side flow path 70, a configuration including the reaction chamber 40 is illustrated.

[0062] 6, in this embodiment, liquid supply paths 10 and 30 are provided for sequentially supplying a plurality of liquids (two types are shown in the figure) L1 and L3 to a reaction chamber 40, and their ends are connected to the reaction chamber 40. A terminal-side path 70 is provided downstream from the reaction chamber 40. This terminal-side path 70 has an outlet 41 provided downstream of the reaction chamber 40 (toward the periphery of the substrate) and branches near the outlet 41 (at a branch point 72). One of the branches is a drainage path 70a connected to a waste liquid tank 50, and the other is a recovery path 70b connected to a recovery tank 60. A first intra-path resistance portion 71 is formed in the branched recovery path 70b near the branch point 72.

[0063] The first in-flow path resistance portion 71 provided in the branched recovery flow path 70b is configured by reducing the flow path cross-sectional area, and when the flow path depth is constant, the flow path cross-sectional area can be reduced by narrowing the flow path width. This reduction in the flow path cross-sectional area can also be achieved by raising the bottom surface, but for convenience of explanation, the flow path width is shown as being narrowed.

[0064] By providing a first in-flow path resistance portion 71 only in the other branch flow path (recovery flow path) 70b without forming an in-flow path resistance portion in one branch flow path (waste flow path) 70a, when liquid flows down the distal side flow path 70, it preferentially flows down the waste flow path 70a. However, if pressure exceeding the limit value (breakdown pressure of the first in-flow path resistance portion 71) for flowing down the waste flow path 70a occurs, the liquid cannot flow down the waste flow path 70a and instead passes through the first in-flow path resistance portion 71 and enters the recovery flow path 70b. Therefore, by providing the first in-flow path resistance portion 71 near the branch point 72 (immediately after the branch), it becomes possible to switch flow paths at the branch point 72.

[0065] Both of the branched flow paths 70a, 70b are configured to be connected to the waste liquid tank 50 or the recovery tank 60 from the periphery of the substrate (not shown) toward the rotation center RC, and both the waste liquid tank 50 and the recovery tank 60 are located downstream (toward the periphery of the substrate) of the branch point 72. Therefore, after being branched, the liquid flowing down each of the flow paths 70a, 70b is filled into each of the tanks 50, 60 in a backflow state with a predetermined pressure. An exhaust unit EP for exhausting air is connected to the side of the rotation center RC of the recovery tank 60. Furthermore, an air supply flow path 80 is connected to the side of the rotation center RC of the waste liquid tank 50, and flows into the liquid supply flow path 30 connected to the next injection reservoir 31, and is continuous with the exhaust unit EP.

[0066] On the other hand, the liquid delivery flow path 30, which allows the next-order liquid L3 to flow down from the next-order injection reservoir 31, has a downstream flow path 34 (here, since the timing chamber and siphon structure are omitted, the downstream side from the end of the bypass flow path 33a is provisionally referred to as the downstream flow path) connected to the reaction chamber 40, allowing the next-order liquid L3 to flow down to the reaction chamber 40 at a delayed timing. Here, this downstream flow path 34 branches at an arbitrary position (branch point) 82 upstream of the connection to the reaction chamber 40, and one of the branches serves as the air delivery flow path 80 and is connected to the waste liquid tank 50. Furthermore, a second intra-flow path resistance 81 is formed at a position appropriately spaced from the branch point 82. Like the first intra-flow path resistance 71, this second intra-flow path resistance 81 is also formed by reducing the flow path cross-sectional area. Any configuration for reducing the flow path cross-sectional area may be used, but for the sake of explanation, a configuration with a narrow flow path width will be illustrated here. The second flow path resistance portion 81 is configured to have a plurality of narrow portions that reduce the cross-sectional area of ​​the flow path, in order to prevent the flow path resistance portion 81 from easily breaking down.

[0067] As described above, the air supply flow path 80 is connected to the waste liquid tank 50 and merges with the downstream flow path 34 via the second flow path resistance portion 81. An exhaust flow path 90 for exhaust is branched off from the downstream flow path 34, and the tip of the exhaust flow path 90 is connected to the exhaust unit EP. Therefore, in a state where the next-order liquid L3 does not flow down to the downstream flow path 34 (a state where the first liquid L1 flows down the first liquid supply flow path 10 and supplies the liquid L1 to the reaction chamber 40), the exhaust path of the waste liquid tank 50 (a path from the air supply flow path 80 to the exhaust flow path 90 via the downstream flow path 34) is continuous, and exhaust is possible. However, when the next-order liquid L3 flows down the downstream flow path 34, once the liquid L3 passes the branch point 92 with the exhaust flow path 90 and further flows down to the branch point 82 with the air supply flow path 80, the exhaust path is blocked, and the air inside the waste liquid tank 50 cannot be discharged. Here, the liquid L3 also flows down the air supply flow path 80 branching off from the downstream flow path 34, but the flow is hindered by the second flow path resistance portion 81, and internal air is trapped between the liquid L3 and the waste liquid that has already flowed into the waste liquid tank 50. Due to this air trapping, the waste liquid that has flowed into the waste liquid tank 50 remains there without being able to move or flow back, and the next liquid L3 that flows into the reaction chamber 40 passes through the reaction chamber 40 and then flows down the other branch flow path 70b of the terminal-side flow path 70.

[0068] In addition, this exhaust flow path 90 also has a third flow path resistance section 91 with a configuration similar to that of the second flow path resistance section 81, but this is provided to prevent the next-level liquid L3 from leaking into the exhaust flow path 90 and is not directly related to the configuration for flow path switching.

[0069] <Operation mode> The operation of the flow path device of this embodiment will be described. Figures 7 and 8 show the operation of flow path switching according to this embodiment. Since this embodiment has the above-mentioned configuration, when liquid transfer begins, all injection reservoirs 11, 31 simultaneously start supplying liquids L1, L3 to the liquid transfer paths 10, 30. At this time, the first liquid first reaches the reaction chamber 40 via the short liquid transfer path 10, and supplies liquid L1 to the reaction chamber 40. Furthermore, the next-order liquid L3 that has flowed out from the next-order injection reservoir 31 is in the middle of flowing down the upstream path and has not yet reached the downstream path 34.

[0070] In this state, the first liquid L1 that has reached the reaction chamber 40 flows out of the reaction chamber 40, passes through the waste liquid flow path 70a in the terminal-side flow path 70, and flows down into the waste liquid tank 50. This is because, as shown in FIG. 7(a), the liquid L3 has not yet reached the downstream flow path 34 of the next-order liquid supply flow path 30, and the air inside the waste liquid tank 50 can be discharged from the exhaust flow path 90 via the air supply flow path 80 and part of the downstream flow path 34. Note that the second intra-flow path resistance portion 81 and the third intra-flow path resistance portion 91 in the middle hinder the passage of the liquid L3, but allow the air to pass freely. As a result, the air inside the waste liquid tank 50 can move freely.

[0071] Furthermore, since the air inside the waste liquid tank 50 can be evacuated without being obstructed, as shown in Figure 7(b), no pressure is generated in the liquid L1 that would cause the first internal resistance portion 71 of the recovery flow path 70b branched off at the branch point 72 of the terminal side flow path 70 to break, and the liquid L1 flows down the waste liquid flow path 70a (and into the waste liquid tank 50 beyond) without branching off to the recovery flow path 70b.

[0072] In contrast, as shown in Figure 8(a), when the next-order liquid L3 reaches the downstream flow path 34 of the next-order liquid supply flow path 30 and flows into the air supply flow path 80 from a branch point 82 located upstream of the original downstream flow path 34 connected to the reaction chamber, the air remaining inside the waste liquid tank 50 and the air supply flow path 80 becomes sealed between the waste liquid (first liquid) L1 that has already flowed into the waste liquid tank 50 and the liquid L3 that has branched at the branch point and flowed into the air supply flow path 80, and the movement of the remaining air becomes restricted.

[0073] Furthermore, the liquid L3 flowing down this downstream flow path 34 flows down under an appropriate pressure due to the action of external forces such as centrifugal force caused by the rotation of the substrate, but the liquid L3 branching off into the gas supply flow path 80 and flowing down does not generate a pressure sufficient to break the second intra-flow path resistance portion 81 (because the breakthrough pressure is adjusted in this manner), and the liquid L3 branching off into the gas supply flow path 80 is prevented from flowing down by the second intra-flow path resistance portion 81, and flows down along the original downstream flow path 34 (towards the reaction chamber 40). Note that the third intra-flow path resistance portion 91 also acts in the same way on the exhaust flow path 90 branched off for exhaust, preventing the liquid L3 from flowing into the exhaust flow path 90.

[0074] In this state, the liquid L1 that has flowed into the waste liquid tank 50 stagnates inside the waste liquid tank 50 and also stagnates in the waste liquid flow path 70a as shown in Fig. 8(b), and when the next liquid L3 flows into the terminal side flow path 70, the pressure of the liquids L1 and L3 acts on the first flow path resistance 71. When the pressure at this time exceeds the breakdown pressure of the first flow path resistance 71, the subsequent liquid L3 can flow down the recovery flow path 70b (flow into the recovery tank 60). This state makes it possible to switch the flow path as needed.

[0075] <Design method for resistance parts in flow paths> As described above, in this embodiment, flow path switching is controlled by the breakthrough pressures (P(S1), P(S2)) of the first and second flow path resistance portions 71, 82. Therefore, a design method for generating predetermined breakthrough pressures (P(S1), P(S2)) in these flow path resistance portions 71, 81 will be described. Note that the cross-sectional areas of the flow paths other than the first and second flow path resistance portions 71, 81 (including the third flow path resistance portion 91) are assumed to be the same.

[0076] First, as described above, the first flow path resistance portion 71 is configured to prevent the first liquid L1 from breaking due to the flow path resistance that increases as the liquid L1 flows into the waste liquid tank 50, in order to allow the first liquid L1 to flow down the waste liquid flow path 70a of the terminal side flow path 70.

[0077] 9, the breakthrough pressure P(S1) at the first flow path resistance portion 71 must be set to be greater than the flow path resistance when the liquid L1 flows down the waste liquid flow path 70a and the surface tension at the inlet when the liquid L1 flows into the waste liquid tank 50. The flow path resistance is generated by the length La of the flow path portion extending in the circumferential direction of the circular orbit around which the waste liquid flow path 70a rotates, and by the length Lb of the flow path portion extending from the periphery toward the center of rotation. Furthermore, surface tension is generated when the liquid L1 flows into the waste liquid tank 50. Therefore, the above condition is expressed as follows:

[0078]

number

[0079] In this way, by making the breakthrough pressure P(S1) of the first flow path resistance portion 71 larger than the flow path resistance during downward flow and the surface tension in the waste liquid tank 50, the first flow path resistance portion 71 does not break when the liquid L1 flows downward, and the liquid passes through the waste liquid flow path 70a, allowing it to flow stably into the waste liquid tank 50.

[0080] Next, the first flow path resistance portion 71 needs to be intentionally broken under predetermined conditions to allow the liquid to pass through the recovery flow path 70b (to switch the flow path.) To achieve this, the breakthrough pressure P(S1) of the first flow path resistance portion 71 needs to be set smaller than the pressure generated by the flow of the next-order liquid L3.

[0081] 10, when the next-order liquid L3 starts to flow down, the liquid L1 that has already flowed into the waste liquid flow path 70a and the waste liquid tank 50 does not move, as described above (note that here it is assumed that the breakthrough pressure of the second intra-flow path resistance portion 81 is normal and that the second intra-flow path resistance portion 81 does not break down). In this state, although a portion of the liquid L2 supplied to the reaction chamber 40 initially flows down into the terminal-side flow path 70 (initially the waste liquid flow path 70a), the flow down is hindered and the liquid L2 is stored in the reaction chamber 40 while the first intra-flow path resistance portion 71 is not broken down. Therefore, the amount of the third liquid stored in the reaction chamber 40 gradually increases, and accordingly, the hydraulic head pressure acting at the position of the first intra-flow path resistance portion 71 increases. At this time, if the breakdown pressure P(S1) of the first flow path resistance section 71 is smaller than the head pressure generated by the accumulation of an appropriate amount of liquid, the first flow path resistance section 71 will break when the accumulated amount is exceeded, allowing liquid L3 to flow into the recovery flow path 70b.

[0082] The conditions at this time are shown in the following formula.

number

[0083] The head pressure P when the first flow path resistance portion 71 breaks h3is determined by the position (height) of the liquid surface stored in the reaction chamber 40, so designing the breakthrough pressure P(S1) of the first flow path resistance portion 71 to be large makes it difficult for the liquid to flow down to the recovery flow path 70b. Also, as shown in Figure 10, if the liquid surface rises above the inlet (inlet portion) of the reaction chamber 40, leakage may occur due to the exhaust portion EP. Therefore, the upper limit P of the head pressure h3max should be the pressure generated until the liquid level reaches the exhaust part EP. However, by positioning the exhaust part EP close to the rotation center RC, the upper limit of the head pressure P h3max However, since the pressure does not exceed the liquid level in the injection reservoir 31, it is preferable to cause the breakage at a lower pressure.

[0084] Referring to the above, the condition for the breakdown pressure P(S1) of the first flow path resistance portion 71 is expressed by the following formula.

number

[0085] Furthermore, the range (upper and lower limits) of the breakdown pressure P(S1) of the first flow path resistance section 71 as described above is as shown in the following formula, and the flow path cross-sectional area should be designed to be reduced so as to fall within that range.

number

[0086] Next, as described above, the second flow path resistance portion 81 serves to seal the internal air of the waste liquid tank 50 and the air supply flow path 80, thereby stopping the movement of the liquid L1 that has flowed into the waste liquid tank 50. Therefore, since there is no need to intentionally cause a breach, there is no need to set an upper limit for the breach pressure P(S2), but a lower limit must be set.

[0087] That is, as shown in FIG. 11, the second flow path resistance portion 81 is provided in a flow path branched from a branch point 82, where the liquid L3 flowing down the next-order liquid sending flow path 30 (downstream flow path 34) is provided. The liquid L3 flows down from this branch point 82 to the position where the second flow path resistance portion 81 is provided, so that a certain amount of head pressure P h1 Therefore, primarily, this head pressure P h1 On the other hand, the liquid L1 that has flowed into the waste liquid tank 50 and the waste liquid flow path 70a remains in these tanks 50 and flow path 70a, and the liquid level of the liquid L1 stored in the waste liquid tank 50 and the liquid level of the liquid L1 remaining in the waste liquid flow path 70a are at different positions (heights), and the pressure difference P h2 acts in the direction of causing the air to flow backward through the air supply flow path 80 (compressing the internal air). h2 acts in the opposite direction on the liquid L3 in the second flow path resistance portion 81, and therefore acts in a direction that reduces the breakthrough pressure P(S2).

[0088] Therefore, to summarize the above, the lower limit value of the breakdown pressure P(S2) in the second flow path resistance portion 81 can be expressed by the following formula.

number

[0089] As described above, the second flow path resistance portion 81 branches off from the next-order liquid sending flow path 30 (downstream flow path 34) and the liquid L3 flows down, so the hydraulic head pressure P h1 This hydraulic head pressure P h1 is the head pressure P required for the liquid L3 flowing into the reaction chamber 40 to flow down to the end-side flow path 70. h3 If this is the case, the liquid L3 in the reaction chamber 40 may not flow down to the end-side flow path 70, but may flow back. Therefore, the position where the second flow path resistance portion 81 is installed (the hydraulic head pressure P acting on the second flow path resistance portion 81) is set to 0.5 mm. h1 ) must satisfy the conditions shown in the formula below.

number

[0090] Since the third flow path resistance section 91 is provided to block the air discharged from the air supply flow path 80, no special conditions are set for its bursting pressure, and it is sufficient that the flow path cross-sectional area is smaller than the surrounding flow path cross-sectional area (of the downstream flow path 34).

[0091] Because this embodiment has the above-described configuration, flow path switching can be easily performed simply by providing an in-flow path resistance portion in the branch flow path after the liquids L1 and L3 to be delivered have passed through the same path (reaction chamber 40). In this configuration, by setting the breakthrough pressure of the in-flow path resistance portion in advance and setting the flow path cross-sectional area according to that breakthrough pressure, no special operation is required, and flow path switching can be performed extremely easily without the need for experience in delivering liquids.

[0092] From such an embodiment, regardless of whether or not the timing chamber is present, in a flow path device in which liquid passes sequentially through the same route (such as a reaction chamber) via multiple flow paths, a first resistance portion within the flow path is provided at one end where the end-side flow path branches, and an air supply flow path connected to a waste liquid tank is connected to one branched from any of the multiple liquid supply flow paths, and a second resistance portion within the flow path is provided near the branch point, thereby making it possible to conceive of an invention as a flow path device capable of switching flow paths.

[0093] <Gene extraction device> Next, an embodiment of a gene extraction device will be described. This embodiment has a structure including a flow path device for sequential liquid supply and a switchable flow path device, and has the same configuration as the overall structure described above.

[0094] 12, this embodiment is configured so that three types of liquids L1, L2, and L3 are supplied to a single reaction chamber 40 via three separate and different liquid supply paths 10, 20, and 30. A branched end-side path 70 is connected to the reaction chamber 40, and a first in-path resistance portion 71 is provided in one of the paths (recovery path 70b) to allow the path to be switched. Liquids passing through the reaction chamber 40 are allowed to flow down to either the waste liquid tank 50 or the recovery tank 60, while being switched between the two. A silica monolith 42 is provided in the reaction chamber 40, and the three types of liquids L1 to L3 stored in the reaction chamber 40 pass through pores formed in the silica monolith 42 in order, and are then distributed to the two tanks 50 and 60.

[0095] Here, the first liquid L1 is a specimen sample, which is an eluate of the test object and contains proteins as well as nucleic acids (DNA and RNA). The second liquid L2 is a washing liquid for removing substances (impurities) such as proteins. The third liquid L3 is an eluate for eluting only nucleic acids. These liquids are sequentially (sequentially) flowed down the reaction chamber 40 starting from the first liquid L1, thereby specifically adsorbing the nucleic acids to the silica monolith 42 and eliminating unnecessary proteins, etc. The liquids used for these processes are then discharged into the waste tank 50, and only the eluate from which the nucleic acids have been eluted is collected in the collection tank 60.

[0096] Although there will be some overlap with the explanation given above, the configuration of this embodiment will be explained below. The three types of liquids L1 to L3 are stored individually in individual injection reservoirs 11, 21, and 31, and by rotating the substrate (not shown) around the rotation center RC, the liquids L1 to L3 stored in the individual injection reservoirs 11 to 31 start to be simultaneously supplied to the liquid delivery channels 10 to 30.

[0097] The first liquid supply flow path 10 does not have a bypass flow path or a timing chamber, has a relatively short flow path length, and is primarily used to supply a specimen sample to the reaction chamber 40. Here, the silica monolith 42 can specifically adsorb nucleic acids contained in the specimen sample. At this time, the first flow path resistance portion 71 does not break, and the specimen sample can flow into the waste liquid tank 50 via the waste liquid flow path 70a.

[0098] The second liquid supply flow path 20 is configured to include a bypass flow path 23a and a timing chamber 1, and can maintain a state in which liquid L2 is not supplied to the reaction chamber 40 until it passes through both of these paths and passes through the siphon structure 22. The length of the bypass flow path 23a and the capacity of the timing chamber 1 are adjusted so that liquid L2 is supplied by the second liquid supply flow path 20 after the first liquid L1 has passed through the reaction chamber 40 (particularly the silica monolith 42). By supplying this second liquid L2 to the reaction chamber 40, unnecessary proteins and the like can be washed away, leaving only nucleic acids that specifically adsorb to the silica monolith 42. This washing liquid (second liquid) L2 also flows into the waste liquid tank 50 via the waste liquid flow path 70a.

[0099] The third liquid supply flow path is configured to include a bypass flow path 33a and two timing chambers 2 and 3, and can supply liquid L3 to reaction chamber 40 after reaching siphon structure 32 via these. The flow path length of bypass flow path 33a is longer than bypass flow path 23a of second liquid supply flow path 20, and the storage volume is increased by the two timing chambers 2 and 3, so that third liquid L3 flows downstream with an even greater delay than second liquid L2.

[0100] Furthermore, this third liquid supply flow path 30 branches off from the downstream flow path 34, one of which is connected to the waste tank 50 as an air supply flow path 80 for the waste tank 50, and is configured to have a second in-flow path resistance portion 81 provided near the branching point. Therefore, after passing through the siphon structure portion 32, this third liquid L3 flows into the branched air supply flow path 80, and in a state where its flow downward is blocked by the second in-flow path resistance portion 81, the movement of the liquids L1 and L2 in the waste tank 50 is restricted, and when the third liquid L3 is supplied to the reaction chamber 40, it is temporarily stored in the reaction chamber 40, and when the hydraulic head pressure increases, it breaks the first in-flow path resistance portion 71 provided in the recovery flow path 70b of the terminal-side flow path 70, and flows into the recovery tank 60.

[0101] Since the third liquid is a nucleic acid elution liquid, it is configured to elute only the nucleic acids that specifically adsorb to the silica monolith 42 of the reaction chamber 40, and to recover only the nucleic acids that have been separated and purified to a high degree of purity in the recovery tank 60.

[0102] <Usage> Since the embodiment of the gene extraction device is configured as described above, predetermined liquids L1, L2, and L3 are stored in each injection reservoir 11, 21, and 31, respectively, and the entire substrate (not shown) is rotated at a predetermined rotation speed (approximately 1500 rpm) around the rotation center RC, whereby the liquids are sequentially (sequentially) supplied to the reaction chamber 40, and adsorption of nucleic acids, washing of proteins, etc., and elution of nucleic acids can be performed sequentially in a predetermined order.

[0103] Only the nucleic acid extraction solution is recovered in the recovery tank 60, and the nucleic acid extraction process is completed with this nucleic acid extraction solution. Gene extraction is then possible by using the resulting nucleic acid (analyzing the base sequence). The first liquid L1 is an eluate from the test object as a specimen sample, and is obtained in advance through a process for extraction from the specimen.

[0104] <Summary> Since the embodiments and modified examples of each device of the present invention are as described above, in a configuration that enables sequential liquid supply, the liquid can continue to flow down from the upstream flow path 23 even after the siphon structure 22, 32 has functioned, and the liquid flowing down the upstream side of the timing chambers 1, 2, 3 (particularly the bypass flow paths 23a, 33a) can be used without waste.

[0105] Furthermore, in a device capable of switching flow paths, in any of the multiple liquid supply flow paths 10, 20, 30, the flow path is switched by connecting the first flow path resistance part 71 to the air supply flow path 80 continuing to the waste liquid tank 50 and sealing the internal air with the second flow path resistance part 81, so that the flow path can be switched automatically by the liquid flowing down the specified flow path without requiring any special operation.

[0106] The gene extraction device is a combination of the above configurations, so after dissolving the test subject, it is possible to recover only nucleic acids (DNA and RNA) while separating impurities such as proteins on the same substrate (device). This can be achieved by simply rotating the substrate at a predetermined rotation speed, making the entire device inexpensive. Naturally, the entire device for gene extraction is inexpensive.

[0107] Although the embodiments of the present invention are as described above, these embodiments are merely examples of the present invention and are not intended to limit the present invention. Therefore, even configurations in which some elements of the above-described embodiments are changed or other elements are added fall within the scope of the present invention.

[0108] For example, in the above-described embodiments, for the sake of convenience, the configuration has been described in which three liquids L1 to L3 are divided into three liquid delivery paths 10 to 30 and pass through a single path (reaction chamber 40), but the number of these is not limited to three and can be increased or decreased depending on the application.

[0109] Furthermore, with regard to the liquid to be recovered in the recovery tank 60 by switching the flow path, the configuration has been described as allowing flow path switching after the liquid in the final order (third in the embodiment) has flowed down, but once the flow path is switched, the same conditions will continue thereafter, so the flow path configuration may also be such that multiple liquids flow into the recovery tank 60 even after switching.

[0110] By making each channel rectangular, a channel having a predetermined cross-sectional area can be formed by varying the depth and width. To manufacture such a channel configuration, for example, a silicone resin (PDMS: polydimethylsiloxane) or the like can be used as a substrate, and the region that will become the channel can be formed in advance by soft lithography, and then a glass substrate or plastic plate can be attached to the surface. However, this is not a limitation. Furthermore, when reducing the cross-sectional area of ​​the channel as a resistance portion within the channel, it is easy to reduce the channel width, but this is not a limitation; the bottom surface can also be raised. [Explanation of symbols]

[0111] 1,2,3 Timing Chamber 10, 20, 30 Liquid delivery channel 11,21,31 Injection reservoir 22,32 Siphon structure 22a Top of the siphon structure 23,33 Upstream channel 23a,33a Detour flow path 24,34 Downstream channel 25, 25a, 25b, 35 Branching point of the liquid flow path 26, 26a, 26b Branch flow path 27 Intermediate channel 40 Reaction Chamber 41 Reaction chamber outlet 42 Silica Monolith 50 Waste liquid tank 60 Recovery Tank 70 Distal channel 70a Waste fluid flow path 70b Recovery channel 71 first flow path resistance portion 72 Branching point of the terminal channel 80 Air supply channel 81 Second flow path resistance portion 82 Branch point with air supply flow path 90 Exhaust flow path 91 Third flow path resistance 92 Exhaust flow path branch point EP exhaust section IP intake section L1,L2,L3 liquid RC rotation center

Claims

1. A flow path device provided on a substrate that can rotate about a predetermined center of rotation, the flow path being configured to allow liquid to be transferred based on an external force generated by the rotation of the substrate, a flow path device comprising: an injection reservoir provided near the rotation center and storing a liquid to be delivered; a waste liquid tank provided away from the rotation center and finally storing the delivered liquid; a timing chamber for adjusting the timing of delivery of the liquid from the injection reservoir to the waste liquid tank; an upstream flow path for delivering the liquid from the injection reservoir to the timing chamber; and a downstream flow path for delivering the liquid from the timing chamber to the waste liquid tank, the upstream flow path is connected to the timing chamber from the periphery of the substrate toward the center of rotation, the downstream flow path branches off near a portion where the upstream flow path connects to the timing chamber, and includes a siphon structure that snakes toward the center of rotation on the way to the waste liquid tank, The timing chamber has an exhaust port connected to the rotation center side. A flow path device characterized by:

2. 2. The flow path device according to claim 1, wherein the upstream flow path is configured to have a long, serpentine flow path length, and is provided with an in-flow path reservoir that adjusts the time it takes for liquid to be sent to the timing chamber by gradually sending liquid from the center of rotation toward the periphery of the substrate as the substrate rotates.

3. 3. The flow path device according to claim 2, wherein a plurality of the timing chambers are arranged side by side at equal distances from the center of rotation, and the plurality of timing chambers are divided into upstream chambers connected to the upstream flow path and next-order chambers connected to intermediate flow paths that branch off near the point where the upstream flow path connects to the upstream chamber, and the downstream flow path branches off near the point where the intermediate flow path connects to the next-order chamber located most downstream.

4. A flow path device is provided on a substrate that can rotate about a predetermined center of rotation, and is configured with flow paths that can send liquids based on an external force generated by the rotation of the substrate, and is used to send multiple liquids to the same reaction chamber sequentially with a time difference while passing through different flow paths, a plurality of injection reservoirs provided near the center of rotation and each for individually storing a plurality of liquids to be delivered; at least one waste liquid tank provided away from the center of rotation and for finally storing the delivered liquids; a single reaction chamber provided between the plurality of injection reservoirs and the waste liquid tank; and a plurality of liquid delivery flow paths for individually delivering liquids between the plurality of injection reservoirs and the reaction chamber, any one of the plurality of liquid feeding paths includes a timing chamber for adjusting the timing of liquid feeding from the injection reservoir to the reaction chamber, an upstream side path for feeding liquid from the injection reservoir to the timing chamber, a downstream side path for feeding liquid from the timing chamber to the reaction chamber, and a terminal side path for feeding liquid from the reaction chamber to the waste liquid tank; the upstream flow path is connected to the timing chamber from the periphery of the substrate toward the center of rotation, the downstream flow path branches off near a portion where the upstream flow path connects to the timing chamber, and includes a siphon structure that snakes toward the center of rotation on the way to the waste liquid tank, The timing chamber, the reaction chamber, and the waste tank are all provided with exhaust ports connected to the rotation center side. A flow path device characterized by:

5. the terminal-side flow path is configured to branch, one of the branches being connected to the waste liquid tank from the periphery side of the substrate toward the rotation center, and the other of the branches being connected to a recovery tank via a first intra-flow path resistance portion, the downstream flow path is configured to branch at a location upstream of connection to the reaction chamber, one branch being connected to the reaction chamber, and the other branch being connected to an air supply flow path for connecting the waste liquid tank to an exhaust part via a second intra-flow path resistance part, an exhaust port of the waste liquid tank is connected via the air supply flow path and the downstream flow path; 5. The flow path device according to claim 4, wherein the first flow path resistance portion is configured to have a breakdown pressure greater than the flow path resistance when the liquid to be discharged is sent to the waste liquid tank and less than the head pressure of the liquid flowing out of the reaction chamber, and the second flow path resistance portion is configured to have a breakdown pressure greater than the head pressure acting on the second flow path resistance portion.

6. 6. The flow path device according to claim 5, wherein the upstream flow path is configured to have a long, serpentine flow path length, and is provided with an in-flow path reservoir that adjusts the time it takes for liquid to be sent to the timing chamber by gradually sending liquid from the center of rotation toward the periphery of the substrate as the substrate rotates.

7. 7. The flow path device according to claim 6, wherein a plurality of the timing chambers are arranged side by side at equal distances from the center of rotation, and the plurality of timing chambers are divided into upstream chambers connected to the upstream flow path and next-order chambers connected to intermediate flow paths that branch off near the point where the upstream flow path connects to the upstream chamber, and the downstream flow path branches off near the point where the intermediate flow path connects to the next-order chamber located most downstream.

8. 8. The flow channel device according to claim 1, wherein each of the flow channels for liquid transfer is a micro flow channel.

9. A gene extraction device using the flow path device according to claim 7, comprising three injection reservoirs, three types of liquid supply flow paths connected thereto, a single reaction chamber, one waste liquid tank, one recovery tank, and an adsorbent material that is installed in the reaction chamber and specifically adsorbs nucleic acids, the first injection reservoir stores a sample solution obtained by eluting the nucleic acid from the test object; the second injection reservoir stores a washing solution for washing away substances other than the nucleic acid; the third injection reservoir stores an elution solution for eluting the nucleic acid; the first liquid supply flow path is connected to the first injection reservoir and is connected to the reaction chamber without the timing chamber; the second liquid delivery channel is connected to the second injection reservoir and includes an in-channel reservoir and one timing chamber; the third fluid delivery channel is connected to the third injection reservoir and includes an in-channel reservoir and two or more timing chambers; A gene extraction device characterized in that the downstream flow path constituting the third liquid supply flow path is configured to branch near the part where the intermediate flow path constituting the third liquid supply flow path connects to the timing chamber located most downstream.

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