Flow path chip

Abstract

The invention provides a flow path chip. The flow path chip (1) has a main flow path (11) and a plurality of sub-flow paths (13). A liquid containing particles flows through the main flow path (11). The plurality of sub-flow paths (13) branch from the main flow path (11). The flow path width (ln) of the sub-flow path (13) is fixed. The lengths of the plurality of sub-flow paths (13) become shorter toward the downstream side in the flow direction (D1) of the liquid flowing through the main flow path (11).

Description

Technical Field

[0001] The present invention relates to a flow path chip (fluidic chip). Background Art

[0002] In the past, a flow channel chip for separating specific cells from blood was known (for example, refer to Patent Document 1). Patent Document 1 describes a flow channel chip having a main flow channel and a plurality of branch flow channels branching from the main flow channel. Blood as a sample liquid flows in the main flow channel. In addition, particles larger than a specified size, such as cancer cells, present in the blood, reach the downstream end of the main flow channel. On the other hand, blood components other than particles larger than a specified size, such as cancer cells, flow in a plurality of branch flow channels. In this way, cancer cells, etc. are separated from the blood.

[0003] In the flow path chip of Patent Document 1, each branch flow path is set to a first width at the starting end side (main flow path side), and is set to a second width wider than the first width at the terminal side. In addition, at the position where the branch flow path switches from the first width to the second width, the flow path closer to the downstream end of the main flow path is set closer to the starting end side.

[0004] Prior art literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-99256 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, in a flow channel chip such as Patent Document 1, it is necessary to make the flow channel resistance value of each branch flow channel appropriate. Therefore, when designing the flow channel of the flow channel chip, the flow channel resistance value to be set for each branch flow channel is calculated, and the width and length of the branch flow channel are set based on the calculation result.

[0008] However, in the flow path chip of Patent Document 1, each branch flow path has: a portion having a first width (hereinafter, sometimes described as a base end portion) and a portion having a second width wider than the first width (hereinafter, sometimes described as a front end portion). The flow path resistance value of the branch flow path is calculated using the length and width of the base end portion and the length and width of the front end portion, so the flow path design of the flow path chip is complicated.

[0009] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a flow channel chip capable of suppressing complexity of flow channel design.

[0010] Means for solving problems

[0011] A flow path chip according to one aspect of the present invention has a main flow path and a plurality of side flow paths. A liquid containing particles flows in the main flow path. The plurality of side flow paths branch from the main flow path. The flow path width of the side flow paths is fixed. As the flow direction of the liquid flowing in the main flow path moves toward the downstream side, the length of the plurality of side flow paths becomes shorter.

[0012] In one aspect of the present invention, the plurality of sub-flow paths may have flow path widths that are the same size as one another.

[0013] In one embodiment of the present invention, the collecting portion may be provided to collect the liquid passing through the plurality of secondary flow paths. The plurality of secondary flow paths may include an upstream secondary flow path disposed at the most upstream of the flow direction and a downstream secondary flow path disposed at the most downstream of the flow direction. At least a portion of the collecting portion may be disposed within a rectangular region. The rectangular region may have a portion between the upstream secondary flow path and the downstream secondary flow path in the main flow path and the upstream secondary flow path as two sides.

[0014] In one aspect of the present invention, the device may include a discharge unit connected to the collecting unit and configured to discharge the liquid collected by the collecting unit. The entire discharge unit may be disposed within the rectangular region.

[0015] In one embodiment of the present invention, a downstream flow path and an electrode may be provided. The downstream flow path may be connected to the downstream end of the main flow path so as to allow the liquid passing through the main flow path to pass through. The electrode may cause dielectric particles contained in the liquid passing through the downstream flow path to undergo dielectrophoresis.

[0016] Effects of the Invention

[0017] According to the present invention, it is possible to provide a flow channel chip capable of suppressing complexity of flow channel design. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a plan view schematically showing the structure of a separation device including the HDF chip according to one embodiment of the present invention.

[0019] Figure 2 It is a plan view schematically showing the structure around the upstream confluence portion of the HDF chip.

[0020] Figure 3 It is a diagram schematically showing the structure around a plurality of auxiliary flow paths.

[0021] Figure 4 This is a schematic diagram for explaining the operating principle of HDF.

[0022] Figure 5This is a schematic diagram showing the peripheral structure of the secondary flow path of a conventional HDF chip.

[0023] Figure 6 It is a schematic diagram showing a flow path model having a rectangular parallelepiped shape.

[0024] Figure 7 It is a schematic diagram showing the structure around the secondary flow path of the HDF chip according to the present embodiment.

[0025] Figure 8 It is a plan view schematically showing the structure of a separation device including an HDF chip according to a modified example of the present invention. DETAILED DESCRIPTION

[0026] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the same reference numerals are given to the same or corresponding parts in the drawings, and the description thereof will not be repeated.

[0027] Reference Figure 1 to Figure 7 , a separation device 100 including the HDF chip 1 according to one embodiment of the present invention will be described. Figure 1 It is a plan view schematically showing the structure of a separation device 100 including the HDF chip 1 according to one embodiment of the present invention.

[0028] like Figure 1 As shown, the separation device 100 of the present embodiment has a HDF (Hydrodynamic filtration) chip 1. The HDF chip 1 has a function as a fluid dynamics filter. For example, the HDF chip 1 is a microchannel chip for the purpose of separating and / or concentrating particles. In the present embodiment, the HDF chip 1 can be used for pathological diagnosis, for example. In addition, for example, the HDF chip 1 is composed of a transparent substrate, etc. In addition, the HDF chip 1 is an example of a "channel chip" of the present invention.

[0029] The HDF chip 1 has at least a main channel 11 and a plurality of side channels 13. In the present embodiment, the HDF chip 1 has the main channel 11, the plurality of side channels 13, the sample liquid supply channel 15, the transport liquid supply channel 17, the upstream confluence portion 19, the collection portion 21, the first outlet 23, and the second outlet 25. In addition, the first outlet 23 is an example of the "discharge portion" of the present invention. The main channel 11, the plurality of side channels 13, the sample liquid supply channel 15, the transport liquid supply channel 17, the upstream confluence portion 19, the collection portion 21, the first outlet 23, and the second outlet 25 are formed, for example, by a resin layer disposed on a transparent substrate. Specifically, all or part of the surfaces constituting the main channel 11, the side channels 13, the sample liquid supply channel 15, the transport liquid supply channel 17, the upstream confluence portion 19, the collection portion 21, the first outlet 23, and the second outlet 25 are formed, for example, by metal, an insulator, a semiconductor, PDMS (dimethylpolysiloxane), glass, and / or a photoresist.

[0030] The main channel 11 extends in a straight line, for example, in a predetermined direction. Liquid flows in the main channel 11. In the present embodiment, the sample liquid 510 flows in the main channel 11. In the present embodiment, the sample liquid 510 and the transport liquid 520 flow in the main channel 11. The sample liquid 510 is a liquid containing particles. The sample liquid 510 is not particularly limited, and is, for example, blood. The transport liquid 520 is, for example, a liquid that does not contain particles. The transport liquid 520 is not particularly limited, and is, for example, a liquid culture medium. The particle size of the particles is, for example, less than tens of μm. In the present embodiment, the particle size of the particles is, for example, greater than 1 μm and less than 20 μm.

[0031] The particle shape is not particularly limited, for example, preferably spherical. However, the particle shape can also be a shape other than spherical. In addition, in the present embodiment, the particle can be a particle consisting of an individual, or a plurality of microparticles can be gathered to form a microparticle group of a block. In addition, the particle can be formed into point symmetry or line symmetry, or can be formed into non-point symmetry or non-line symmetry. In addition, the particle can not form concavo-convex on the surface, or can form concavo-convex on the surface.

[0032] A plurality of side flow paths 13 are branched from the main flow path 11. Specifically, the plurality of side flow paths 13 are arranged at approximately equal intervals, for example, along the extension direction of the main flow path 11. The plurality of side flow paths 13 extend in a direction intersecting the main flow path 11. In the present embodiment, the plurality of side flow paths 13 extend in a direction orthogonal to the main flow path 11. In the present embodiment, the plurality of side flow paths 13 are connected perpendicularly to the main flow path 11. However, the plurality of side flow paths 13 are preferably connected perpendicularly to the main flow path 11, but may also be connected at a non-perpendicular angle to the main flow path 11.

[0033] The HDF2 is composed of a main channel 11 and a plurality of side channels 13. Specifically, a part of the liquid flowing in the main channel 11 flows into the plurality of side channels 13. In addition, a part of the particles contained in the liquid flowing in the main channel 11 flows into the plurality of side channels 13. Whether the particles flow into the plurality of side channels 13 depends on, for example, the particle size. However, even particles with a particle size smaller than the channel width of the side channels 13 do not necessarily flow into the side channels 13. The smaller the particle size, the easier it is for the particles to flow into the side channels 13, and the larger the particle size, the more difficult it is for the particles to flow into the side channels 13. For example, when blood is used as the sample liquid 510, the liquid components of the blood, namely, plasma (also called Plasma), red blood cells, and platelets, can be made to flow in the side channels 13, and the cancer cells and white blood cells contained in the blood can be made not to flow in the side channels 13. That is, for example, particles with large particle sizes, such as cancer cells and white blood cells, can be separated from the blood. In addition, the operating principle of the HDF2 will be described later.

[0034] In addition, the plurality of secondary flow paths 13 are formed such that the flow path resistance gradually decreases from the upstream side toward the downstream side of the main flow path 11. Specifically, in the present embodiment, the flow path width of each secondary flow path 13 is fixed. That is, the flow path width of each secondary flow path 13 is fixed from the end of the base end side (main flow path 11 side) to the end of the front end side (the side away from the main flow path 11). Therefore, the secondary flow path 13 as a whole contributes to particle separation. That is, when designing the secondary flow path 13 as described later, the flow path resistance of the secondary flow path 13 as a whole is used.

[0035] In addition, as the flow direction D1 of the liquid flowing in the main flow path 11 is directed toward the downstream side, the length of the plurality of side flow paths 13 becomes shorter. In other words, as the downstream end of the main flow path 11 is approached, the length of the side flow path 13 becomes shorter. In the present embodiment, the length of the side flow path 13 gradually becomes shorter as the downstream end of the main flow path 11 is approached. In addition, in the present embodiment, all the side flow paths 13 are formed to have different lengths from each other. In other words, the lengths of the plurality of side flow paths 13 are all different from each other. In addition, in the present embodiment, the flow path widths of the plurality of side flow paths 13 are the same size as each other. The flow path width of the side flow path 13 is not particularly limited, and is, for example, about 10 μm to several tens of μm. In addition, in the present embodiment, the type of particles to be separated is the same in all the side flow paths 13.

[0036] Figure 2 1 is a top view schematically showing the structure around the upstream confluence portion 19 of the HDF chip 1. Figure 2As shown, the sample liquid 510 flows in the sample liquid supply flow path 15. The sample liquid supply flow path 15 is a flow path for supplying the sample liquid 510 to the main flow path 11. In addition, in the present embodiment, the sample liquid supply flow path 15 is inclined relative to the main flow path 11, but the present invention is not limited thereto. For example, the sample liquid supply flow path 15 may be parallel to the main flow path 11 or may be perpendicular to the main flow path 11.

[0037] The transport liquid 520 flows in the transport liquid supply flow path 17. The transport liquid supply flow path 17 is a flow path for supplying the transport liquid 520 to the main flow path 11. The transport liquid 520 is, for example, a liquid for transporting particles larger than a specified particle size. In other words, the transport liquid 520 is a liquid for transporting particles that have not flowed into the secondary flow path 13 to the downstream side of the main flow path 11. In addition, in the present embodiment, the transport liquid supply flow path 17 is inclined relative to the main flow path 11, but the present invention is not limited to this. For example, the transport liquid supply flow path 17 can be parallel to the main flow path 11 or perpendicular to the main flow path 11.

[0038] In addition, the sample liquid supply flow path 15 is configured so that the sample liquid 510 flows in the portion on the side of the secondary flow path 13 in the main flow path 11. On the other hand, the transport liquid supply flow path 17 is configured so that the transport liquid 520 flows in the portion on the opposite side of the secondary flow path 13 in the main flow path 11. In the present embodiment, the sample liquid supply flow path 15 is connected to the inner wall 111 on the side of the secondary flow path 13 among the inner walls of the main flow path 11. On the other hand, the transport liquid supply flow path 17 is connected to the inner wall 112 on the opposite side of the secondary flow path 13 among the inner walls of the main flow path 11.

[0039] The sample liquid supply flow path 15 merges with the transport liquid supply flow path 17 at the upstream merging portion 19. The upstream merging portion 19 is disposed at the upstream end of the main flow path 11. Therefore, the sample liquid 510 that has passed through the sample liquid supply flow path 15 and the transport liquid 520 that has passed through the transport liquid supply flow path 17 merge at the upstream merging portion 19 and flow in the main flow path 11.

[0040] like Figure 1 As shown, the collecting part 21 collects the liquid passing through the plurality of auxiliary flow paths 13. The collecting part 21 is connected to the plurality of (here, all) auxiliary flow paths 13. In addition, the collecting part 21 is connected to the first outlet 23. The collecting part 21 collects the liquid passing through the plurality of auxiliary flow paths 13 and guides it to the first outlet 23.

[0041] The liquid that has passed through the plurality of sub-flow paths 13 is recovered in a first recovery portion (not shown) via the collection portion 21 and the first outlet 23. The first recovery portion includes, for example, a recovery container.

[0042] The second outlet 25 is connected to the downstream end of the main flow path 11. Therefore, the liquid that has passed through the main flow path 11 flows toward the second outlet 25. Particles larger than the specified particle size contained in at least the sample liquid 510 flow in the second outlet 25. In the present embodiment, the transport liquid 520 containing particles larger than the specified particle size flows. The liquid that has passed through the main flow path 11 (here, the transport liquid 520) is recovered to a second recovery unit (not shown) via the second outlet 25. The second recovery unit includes, for example, a recovery container.

[0043] Next, refer to Figure 3 The structure around the plurality of auxiliary flow paths 13 will be described. Figure 3 Schematically shows the structure of the peripheral parts of the plurality of secondary flow paths 13. Figure 3 In the figure, the number of the auxiliary flow paths 13 is reduced for easy understanding.

[0044] like Figure 3 As shown, the plurality of secondary flow paths 13 include an upstream secondary flow path 131 disposed at the most upstream of the flow direction D1, and a downstream secondary flow path 132 disposed at the most downstream of the flow direction D1. The upstream secondary flow path 131 is connected to a portion of the main flow path 11 on the most upstream side of the flow direction D1 compared to the other secondary flow paths 13. The downstream secondary flow path 132 is connected to a portion of the main flow path 11 on the most downstream side of the flow direction D1 compared to the other secondary flow paths 13.

[0045] Here, the portion of the main flow path 11 disposed between the most upstream secondary flow path 131 and the most downstream secondary flow path 132 is referred to as the portion 115. Furthermore, a rectangular region having the portion 115 and the most upstream secondary flow path 131 as two sides is referred to as the region 600. In the present embodiment, at least a portion of the collecting section 21 is disposed in the region 600. Specifically, a portion of the collecting section 21 other than the periphery of the most upstream secondary flow path 131 is disposed in the region 600. That is, most of the collecting section 21 is disposed in the region 600.

[0046] In addition, in the present embodiment, the first outlet 23 is arranged in the region 600. Specifically, the entire first outlet 23 is arranged in the rectangular region 600.

[0047] Continue to refer to Figure 1 , the separation device 100 and the HDF chip 1 are further described. The separation device 100 also has a sample liquid feeding unit 31 and a transport liquid feeding unit 33. The separation device 100 may have a control device that drives the sample liquid feeding unit 31 and the transport liquid feeding unit 33. The sample liquid feeding unit 31 and the transport liquid feeding unit 33 are not particularly limited, and are, for example, micro pumps. The micro pump may be a mechanical pump or a non-mechanical pump.

[0048] The control device may include, for example, a control unit and a storage unit. The control unit may include, for example, a processor. The control unit may include, for example, a central processing unit (CPU) or a general-purpose computer. The storage unit may include, for example, a main storage device and an auxiliary storage device. The main storage device may be, for example, a semiconductor memory. The auxiliary storage device may be, for example, a semiconductor memory and / or a hard disk drive. The storage unit may include a removable medium.

[0049] The sample liquid feeding section 31 is connected to the sample liquid supply flow path 15, and allows the sample liquid 510 to flow in the sample liquid supply flow path 15. Specifically, the sample liquid supply flow path 15 has a sample liquid inlet 151. The sample liquid inlet 151 is arranged at the upstream end of the sample liquid supply flow path 15. The sample liquid feeding section 31 is connected to the sample liquid inlet 151. The sample liquid feeding section 31 supplies the sample liquid 510 to the sample liquid inlet 151, thereby allowing the sample liquid 510 to flow in the sample liquid supply flow path 15 and the main flow path 11.

[0050] The transport liquid feeding section 33 is connected to the transport liquid supply flow path 17, and allows the transport liquid 520 to flow in the transport liquid supply flow path 17. Specifically, the transport liquid supply flow path 17 has a transport liquid inlet 171. The transport liquid inlet 171 is arranged at the upstream end of the transport liquid supply flow path 17. The transport liquid feeding section 33 is connected to the transport liquid inlet 171. The transport liquid feeding section 33 supplies the transport liquid 520 to the transport liquid inlet 171, thereby allowing the transport liquid 520 to flow in the transport liquid supply flow path 17 and the main flow path 11.

[0051] In this embodiment, the sample liquid supply unit 31 supplies the sample liquid 510 so that the sample liquid 510 forms a laminar flow. The transfer liquid supply unit 33 supplies the transfer liquid 520 so that the transfer liquid 520 forms a laminar flow. Therefore, in this embodiment, each liquid forms a laminar flow in the HDF chip 1.

[0052] Next, refer to Figure 4 The operating principle of HDF2 is described below. Figure 4 This is a schematic diagram used to explain the operating principle of HDF2. Figure 4 As shown in FIG. 1 , when the sample liquid feeding section 31 supplies the sample liquid 510 and the transport liquid feeding section 33 supplies the transport liquid 520, the sample liquid 510 and the transport liquid 520 flow in the main channel 11. The sample liquid 510 flows along the inner wall 111 on the side of the secondary channel 13, and the transport liquid 520 flows along the inner wall 112 on the opposite side of the secondary channel 13. At this time, the center of each particle passes through a position that is more than the particle radius away from the inner wall 111 of the main channel 11.

[0053] Here, the fluid located within a predetermined distance from the inner wall 111 of the main channel 11 flows into the secondary channel 13. On the other hand, the fluid flowing at a position farther from the inner wall 111 than the predetermined distance does not flow into the secondary channel 13 and flows straight in the main channel 11.

[0054] Therefore, particles having a small particle size and passing through the vicinity of the inner wall 111 flow into the secondary flow channel 13. On the other hand, particles having a large particle size and passing through a position away from the inner wall 111 do not flow into the secondary flow channel 13, but go straight in the main flow channel 11. That is, under specified conditions, particles larger than a specified size are not discharged from the main flow channel 11, and on the other hand, particles below a specified size are discharged from the main flow channel 11. The discharge from the main flow channel 11 to the secondary flow channel 13 is repeatedly performed through a plurality of secondary flow channels 13, and therefore, particles below a specified size do not reach the downstream end of the main flow channel 11. In addition, plasma, which is a liquid component, does not reach the downstream end of the main flow channel 11 either. Therefore, particles having a large particle size, such as cancer cells and leukocytes, can be separated from blood by the HDF chip 1.

[0055] Next, refer to Figure 5 to Figure 7 , the method for setting the length and width of the secondary flow path 13 is described. In other words, the method for designing the secondary flow path 13 is described. Here, in order to easily understand the effect of this embodiment, the following is used. Figure 5 and Figure 6 First, the design method of the secondary flow path 1013 in the existing HDF chip is described. Figure 5 It is a schematic diagram showing the peripheral structure of the secondary flow path 1013 of a conventional HDF chip. Figure 6 It is a schematic diagram showing a flow path model having a rectangular parallelepiped shape.

[0056] like Figure 5 As shown, in the conventional HDF chip, a portion 10131 of the base end side (the side close to the main flow path 1011) of each auxiliary flow path 1013 is formed to have a first width. On the other hand, a portion 10132 of the front end side (the side away from the main flow path 1011) of each auxiliary flow path 1013 is formed to have a second width greater than the first width. And, as it moves toward the downstream side of the flow direction D1, the position where the first width changes to the second width is arranged on the base end side.

[0057] Here, the length of the secondary flow path 1013 is set to L, the length of the portion 10131 is set to Ln, and the length of the portion 10132 is set to Lw. In addition, the flow path width of the portion 10131 is set to ln, and the flow path width of the portion 10132 is set to lw. In addition, the height of the secondary flow path 1013 is set to T. In addition, the mathematical formula used in the following description is a mathematical formula used when the height T> the flow path width ln and the height T> the flow path width lw. However, when the height T≤the flow path width ln, for example, in the following mathematical formula, f(T, ln) can be set to f(ln, T). In addition, when the height T≤the flow path width lw, for example, in the following mathematical formula, f(T, lw) can be set to f(lw, T).

[0058] The height T of the secondary flow path 1013 is the size in the direction perpendicular to the length direction and the width direction of the secondary flow path 1013. Figure 5 The size of the paper surface perpendicular to the paper surface. In addition, the height T of the auxiliary flow path 1013 is fixed. In addition, the height of the portion 10131 of the auxiliary flow path 1013 is the same as the height of the portion 10132. In addition, the flow path resistance of the auxiliary flow path 1013 is set to R. In addition, the proportional constant is set to k.

[0059] At this time, the length Ln of the portion 10131 can be expressed by the following equation (1). In addition, the length Lw of the portion 10132 can be expressed by the following equation (2). k>0, g(T, lw, ln)>0.

[0060] [Mathematical formula 1]

[0061]

[0062] [Mathematical formula 2]

[0063]

[0064] In addition, the function f in the above equations (1) and (2) is based on the following well-known equation (3). Specifically, Figure 6 As shown, the larger of the height and the width of the flow path 1113 having a rectangular parallelepiped shape is set to a, and the smaller of the height and the width of the flow path 1113 is set to b. At this time, the function f(a, b) is represented by equation (3). In addition, for example, the height is set to a and the flow path width is set to b.

[0065] [Mathematical formula 3]

[0066]

[0067] In addition, in the above-mentioned formula (1), the length Ln is a positive value, and therefore, the following formula (4) must be satisfied.

[0068] [Formula 4]

[0069]

[0070] In addition, in the above-mentioned formula (2), the length Lw is a positive value, and therefore, the following formula (5) must be satisfied.

[0071] [Formula 5]

[0072]

[0073] The flow path resistance R to be set for each secondary flow path 1013 is calculated in advance by a known method. In addition, the length L, flow path width ln, flow path width lw and height T of all the secondary flow paths 1013 are equal to each other. That is, the length L of all the secondary flow paths 1013 is equal to each other. In addition, the flow path width ln of all the secondary flow paths 1013 is equal to each other. In addition, the flow path width lw of all the secondary flow paths 1013 is equal to each other. In addition, the height T of all the secondary flow paths 1013 is equal to each other.

[0074] Therefore, when designing the auxiliary flow path of the existing HDF chip, the length Ln and the length Lw of each auxiliary flow path 1013 are calculated using the above formula (1) and formula (2) so that the length L, the flow path width ln, the flow path width lw and the height T of all the auxiliary flow paths 1013 are equal to each other, and the flow path resistance R of each auxiliary flow path 1013 is a specified value. At this time, it is also necessary to set the length L, the flow path width ln, the flow path width lw and the height T to satisfy the above formula (4) and formula (5).

[0075] On the other hand, the secondary flow path 13 of the HDF chip 1 of the present embodiment can be designed as follows. Figure 7 Schematic diagram showing the structure around the secondary flow path 13 of the HDF chip 1 according to the present embodiment.

[0076] Specifically, if Figure 7 As shown in FIG. 1 , the length of the secondary flow path 13 is L, the flow path width is ln, and the height is T. The height T of the secondary flow path 13 is the size in the direction perpendicular to the length direction and the width direction of the secondary flow path 13. That is, the height T of the secondary flow path 13 is perpendicular to the length direction and the width direction of the secondary flow path 13. Figure 7 The size of the paper surface perpendicular to the paper surface. In addition, the height T of the secondary flow path 13 is fixed. The flow path width ln of the secondary flow path 13 is also fixed. In addition, the flow path resistance of the secondary flow path 13 is set to R. In addition, the proportional constant is set to k.

[0077] At this time, the length L of the secondary flow path 13 is expressed by the following well-known formula (6). In addition, k>0.

[0078] [Mathematical formula 6]

[0079] L=kRf(T,ln)…(6)

[0080] The flow path resistance R to be set for each secondary flow path 13 is calculated in advance by a known method. In addition, the length L and height T of all the secondary flow paths 13 are equal to each other. That is, the length L of all the secondary flow paths 13 is equal to each other. In addition, the height T of all the secondary flow paths 13 is equal to each other.

[0081] Therefore, when designing the secondary flow paths 13 of the HDF chip 1 of the present embodiment, the length L of each secondary flow path 13 is calculated using the above formula (6) so that the flow path width ln and height T of all the secondary flow paths 13 are equal to each other and the flow path resistance R of each secondary flow path 13 becomes a predetermined value. Figure 5 Unlike the case where the length Ln and the length Lw of the secondary flow path 1013 are calculated, the constraints shown in the above equations (4) and (5) do not need to be satisfied.

[0082] As described above, in this embodiment, the number of parameters (for example, length and channel width) required when designing the auxiliary channel 13 is reduced, and the constraints such as those shown in the above-mentioned equations (4) and (5) do not need to be satisfied.

[0083] Above, as reference Figure 1 to Figure 7 As described above, in the present embodiment, the flow path width of the secondary flow path 13 is fixed. In addition, as the flow direction D1 of the liquid flowing in the main flow path 11 is directed toward the downstream side, the length of the plurality of secondary flow paths 13 becomes shorter. Therefore, when designing the flow path (main flow path 11 and plurality of secondary flow paths 13) of the HDF chip 1, the number of parameters required for the design can be reduced compared to the case of designing the flow path of the existing HDF chip. In addition, when designing the flow path of the HDF chip 1, unlike the case of designing the flow path of the existing HDF chip, the constraints shown in the above-mentioned equations (4) and (5) may not be satisfied. Therefore, in the HDF chip 1 of the present embodiment, the complexity of the flow path design can be suppressed.

[0084] Furthermore, since the constraints shown in the above-mentioned equations (4) and (5) do not need to be satisfied, the degree of freedom in design can be increased.

[0085] In addition, as the length of the plurality of side channels 13 becomes shorter toward the downstream side of the flow direction D1 of the liquid flowing in the main channel 11, the area of ​​the HDF 2 can be reduced. Therefore, the amount of material used for the HDF chip 1 can be reduced. Therefore, it is helpful to reduce the cost of the HDF chip 1. In addition, according to the estimation of the inventor of the present application, the HDF 2 of the HDF chip 1 of the present embodiment can reduce the area by about 43% compared with the HDF of the existing HDF chip.

[0086] Furthermore, as described above, the channel widths of the plurality of sub-channels 13 are the same size as each other. Therefore, it is possible to easily suppress the complexity of calculations when designing the channel of the HDF chip 1.

[0087] In addition, as described above, at least a portion of the collecting section 21 is arranged in a rectangular region 600 having the portion 115 and the most upstream secondary flow path 131 as two sides. Therefore, it is possible to arrange at least a portion of the collecting section 21 in the region where the secondary flow path 1013 is arranged in the existing HDF chip. Therefore, it is possible to easily reduce the area of ​​the HDF chip 1. Therefore, it is possible to easily reduce the amount of material used for the HDF chip 1. In addition, the region 600 corresponds to the region where the HDF (main flow path 1011 and a plurality of secondary flow paths 1013) is arranged in the existing HDF chip.

[0088] In addition, as described above, the entire first outlet 23 is arranged in the rectangular region 600. Therefore, the region where the secondary flow path 1013 is arranged in the existing HDF chip can be used to arrange the entire first outlet 23. Therefore, the area of ​​the HDF chip 1 can be further reduced. Therefore, the amount of material used for the HDF chip 1 can be further reduced.

[0089] Next, refer to Figure 8 , a separation device 300 according to a modified example of the present invention is described. Figure 8 1 is a plan view schematically showing the structure of a separation device 300 including an HDF chip 301 according to a modified example of the present invention.

[0090] like Figure 8 As shown, in the separation device 300 of the modified example of the present invention, the HDF chip 301 has: a main flow path 11, a transport liquid supply flow path 26, a downstream flow path 27, a first recovery channel 51, and a second recovery channel 53. In addition, the HDF chip 301 has: a plurality of side flow paths 13, a sample liquid supply flow path 15, a transport liquid supply flow path 17, an upstream confluence portion 19, a collection portion 21, and a first outlet 23, similarly to the HDF chip 1. In addition, the HDF chip 301 is an example of the "flow path chip" of the present invention.

[0091] The transport liquid 530 flows in the transport liquid supply flow path 26. The transport liquid supply flow path 26 is a flow path for supplying the transport liquid 530 to the downstream flow path 27. The transport liquid 530 is, for example, a liquid for transporting particles separated by dielectrophoresis described later to the first recovery channel 51. The transport liquid 530 is, for example, a liquid that does not contain particles. In addition, the transport liquid 530 is not particularly limited, and for example, it is the same composition as the transport liquid 520.

[0092] The downstream flow path 27 is connected to the downstream end of the main flow path 11 and the downstream end of the liquid supply flow path 26. For example, the flow path width of the downstream flow path 27 is larger than the flow path width of the main flow path 11 and the flow path width of the liquid supply flow path 26. In addition, in this modified example, the flow path width of the downstream flow path 27 is larger than the sum of the flow path width of the main flow path 11 and the flow path width of the liquid supply flow path 26. In addition, the height of the downstream flow path 27 is the same as the height of the main flow path 11 and the height of the liquid supply flow path 26.

[0093] By making the flow width of the downstream flow channel 27 larger than the flow width of the main flow channel 11, the flow velocity of the liquid flowing in the downstream flow channel 27 can be reduced. Therefore, particle separation by dielectrophoresis described later can be easily performed.

[0094] The first recovery passage 51 and the second recovery passage 53 are connected to the downstream end of the downstream flow path 27. That is, the downstream flow path 27 is branched into the first recovery passage 51 and the second recovery passage 53.

[0095] In the HDF chip 301 , the second outlet 25 includes a second outlet 251 and a second outlet 252 . The second outlet 251 is connected to the downstream end of the first recovery channel 51 , and the second outlet 252 is connected to the downstream end of the second recovery channel 53 .

[0096] Here, the HDF chip 301 can further separate the particles flowing in the downstream side flow path 27 by dielectrophoresis (DEP). Specifically, the HDF chip 301 also has: an electrode 55 and an electrode 57 arranged in a manner overlapping with the downstream side flow path 27. The electrode 55 and the electrode 57 are comb-shaped electrodes facing each other. The electrode 55 is connected to an AC power supply 61, for example. The electrode 57 is grounded, for example. In this modification, the separation device 300 has an AC power supply 61. In addition, the separation device 300 may not have the AC power supply 61.

[0097] The teeth of the electrode 55 and the electrode 57 are inclined, for example, by 10° or more and 60° or less relative to the downstream flow path 27. By applying an AC voltage between the electrode 55 and the electrode 57 using the AC power supply 61, dielectrophoresis can be generated. In addition, by adjusting the frequency of the applied AC voltage, desired particles can be separated and recovered from a variety of particles passing through the downstream flow path 27.

[0098] Specifically, when the plurality of particles passing through the downstream flow path 27 include dielectric particles, specific dielectric particles can be separated from the plurality of particles by DEP. For example, cancer cells and leukocytes are dielectric particles. When the plurality of particles passing through the downstream flow path 27 include cancer cells and particles (leukocytes, etc.) larger than a specified size other than cancer cells, for example, an AC voltage of a specific frequency is applied between the electrode 55 and the electrode 57 so that the dielectrophoretic force easily acts on the cancer cells. Thus, the cancer cells can be moved along the electrode 55 and the electrode 57, and therefore, only the cancer cells can be induced to the second outlet 251 by dielectrophoresis. Therefore, the cancer cells can be separated from other particles (leukocytes, etc.).

[0099] The other structures of the separation device 300, HDF chip 301, main flow path 11, multiple side flow paths 13, sample liquid supply flow path 15, transport liquid supply flow path 17, upstream confluence section 19, collection section 21, and first outlet 23 of the modified example of the present invention are the same as those of the separation device 100, HDF chip 1, main flow path 11, multiple side flow paths 13, sample liquid supply flow path 15, transport liquid supply flow path 17, upstream confluence section 19, collection section 21, and first outlet 23 of the above-mentioned embodiment. In addition, other effects of the modified example of the present invention are the same as those of the above-mentioned embodiment.

[0100] As described above, the HDF chip 301 of the modified example of the present invention includes: the downstream side flow path 27 connected to the downstream end of the main flow path 11, through which the liquid passing through the main flow path 11 passes; and the electrodes 55 and 57, which cause the dielectric particles (here, cancer cells) contained in the liquid passing through the downstream side flow path 27 to undergo dielectrophoresis. Therefore, it is possible to easily separate specific dielectric particles (here, cancer cells) from the liquid passing through the main flow path 11.

[0101] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the above-mentioned embodiments and can be implemented in various ways without departing from the spirit thereof. In addition, various inventions can be formed by appropriately combining the multiple constituent elements disclosed in the above-mentioned embodiments. For example, several constituent elements can be deleted from all the constituent elements shown in the embodiments. Moreover, the constituent elements of different embodiments can also be appropriately combined. In the accompanying drawings, for ease of understanding, each constituent element is schematically displayed as the main body, and the thickness, length, number, spacing, etc. of each constituent element shown in the drawings are sometimes different from the actual ones for the convenience of drawing production. In addition, the material, shape, size, etc. of each constituent element shown in the above-mentioned embodiments are examples, and are not particularly limited, and various changes can be made within the scope that does not substantially depart from the effect of the present invention.

[0102] For example, in the above embodiment, blood is used as the sample liquid 510 and a liquid culture medium is used as the transport liquid 520, but the present invention is not limited thereto. For example, a liquid other than blood may be used as the sample liquid 510 and a liquid other than a culture medium may be used as the transport liquid 520.

[0103] In the above embodiment, particles (such as cancer cells and white blood cells) recovered from the second outlet 25 are cited as an example of target recovery, but the present invention is not limited thereto. For example, particles or liquid components recovered from the first outlet 23 may also be used as target recovery.

[0104] In the above modification, an example of collecting target particles (eg, cancer cells) from the second outlet 251 is described, but the present invention is not limited thereto. For example, the target particles may be collected from the second outlet 252 .

[0105] In addition, in the above-mentioned embodiment, an example of using a liquid that does not contain particles (for example, the transport liquid 520) is described. That is, an example of causing a liquid that does not contain particles (for example, the transport liquid 520) to flow in the main flow path 11 in addition to a liquid that contains particles (for example, the sample liquid 510) is described. However, the present invention is not limited to this. For example, only a liquid that contains particles (for example, the sample liquid 510) may be caused to flow in the main flow path 11. For example, as a liquid that contains particles (for example, the sample liquid 510), seawater that contains particles may be used to separate particles from the seawater.

[0106] In addition, in the above embodiment, an example is described in which a liquid containing particles (e.g., sample liquid 510) and a liquid not containing particles (e.g., transport liquid 520) are merged on the HDF chip 1, but the present invention is not limited thereto. For example, a mixed liquid in which a liquid containing particles (e.g., sample liquid 510) and a liquid not containing particles (e.g., transport liquid 520) are mixed may be supplied to the HDF chip 1.

[0107] In addition, in the above-mentioned embodiment, an example is described in which the liquid passing through all the auxiliary flow paths 13 is collected in one collecting part 21, but the present invention is not limited thereto. For example, a collecting part for collecting the liquid passing through a part of the auxiliary flow paths 13 among the plurality of auxiliary flow paths 13 and a collecting part for collecting the liquid passing through the remaining auxiliary flow paths 13 among the plurality of auxiliary flow paths 13 may be provided separately. In addition, three or more collecting parts may be provided. In addition, the collecting part and / or the first outlet may not be provided.

[0108] In the above embodiment, the example in which each auxiliary flow path 13 extends in a straight line is described, but the present invention is not limited thereto. For example, part or all of the plurality of auxiliary flow paths 13 may be bent in the middle of the flow path.

[0109] In the above embodiment, the example in which the secondary flow path 13 is connected to one of the inner walls 111 and 112 of the primary flow path 11 (the inner wall 111) is described, but the present invention is not limited thereto. For example, the secondary flow path 13 may be connected to both the inner wall 111 and the inner wall 112.

[0110] In addition, in the above-mentioned embodiment, an example in which a structure such as a sensor is not arranged in the flow path (for example, the main flow path 11 and the secondary flow path 13) of the HDF chip 1 is described, but the present invention is not limited to this. For example, as long as the particles can be separated, a structure such as a physical sensor, an electric sensor, or a magnetic sensor may be arranged in the flow path (for example, the main flow path 11 and the secondary flow path 13) of the HDF chip 1.

[0111] In addition, in the above embodiment, if Figure 7 As shown, an example is shown in which, at the front end of the secondary flow path 13, the side wall in the flow path width direction of the secondary flow path 13 is not connected to the side wall outside the secondary flow path 13, but the present invention is not limited thereto. For example, a side wall extending outward from the front end of the secondary flow path 13 may also be formed. However, the side wall connected to the front end of the secondary flow path 13 is a side wall that does not effectively contribute to particle separation. In other words, as long as the side wall can ignore the flow path resistance when designing the secondary flow path 13, it may also be connected to the front end of the secondary flow path 13.

[0112] Possibility of Industrial Application

[0113] The present invention can be applied to the field of flow path chips.

[0114] Explanation of symbols

[0115] 1. 301: HDF chip (flow path chip)

[0116] 11: Mainstream Road

[0117] 13: Side Flow Path

[0118] 21: Collection Department

[0119] 23: First outlet (discharge portion)

[0120] 27: Downstream flow path

[0121] 55: Electrode

[0122] 57: Electrode

[0123] 115: Part

[0124] 131: Upstream secondary flow path

[0125] 132: The most downstream secondary flow path

[0126] 510: Sample liquid (liquid)

[0127] 600: Area

[0128] D1: Flow direction

[0129] L: Length

[0130] ln: flow path width.

Claims

1. A flow channel chip, characterized in that: have: a main flow path for a liquid containing particles to flow; and a plurality of secondary flow paths branching from the primary flow path, The secondary flow path has a fixed flow path width. The lengths of the plurality of sub-flow paths are shortened toward the downstream side in the flow direction of the liquid flowing through the main flow path.

2. The flow path chip according to claim 1, characterized in that: The flow channel widths of the plurality of sub-flow channels are the same size as each other.

3. The flow channel chip according to claim 1 or 2, characterized in that: The flow channel chip comprises: a collecting portion that collects the liquid passing through the plurality of sub-flow channels; The plurality of secondary flow paths include: an upstream-most secondary flow path disposed at the upstream-most position in the flow direction, and a downstream-most secondary flow path disposed at the downstream-most position in the flow direction. At least a portion of the collecting portion is disposed in a rectangular region having a portion between the most upstream secondary flow path and the most downstream secondary flow path in the main flow path and the most upstream secondary flow path as two sides.

4. The flow path chip according to claim 3, characterized in that: The flow channel chip comprises: a discharge portion connected to the collection portion and configured to discharge the liquid collected by the collection portion; The entire discharge portion is disposed within the rectangular region.

5. The flow channel chip according to claim 1 or 2, characterized in that: The flow path chip has: a downstream flow path connected to a downstream end of the main flow path and allowing the liquid passing through the main flow path to pass therethrough; and The electrode causes the dielectric particles contained in the liquid passing through the downstream flow path to undergo dielectrophoresis.

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