JP2011027590A - Microfluid chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microfluid chip for simplifying a mechanism, controlling a flow of a fluid, and correctly weighing the fluid accommodated in a cell. <P>SOLUTION: In the microfluid chip 1 comprising: the weighing cell D11 having a fluid introduction port 11a for introducing the fluid into the weighing cell D11, and a fluid discharge port 12a for discharging the excess fluid exceeding the accommodation volume of the weighing cell D11; and a transfer control flow path LF11 coupled to the weighing cell D11 at one end, and deactivating a flow of the fluid by a Laplace force acting in the direction opposite to the direction of the flow of the fluid, the weighing cell D11 is filled with the fluid by deactivating the flow of the fluid flowing by a capillary phenomenon under the Laplace force applied to an end on the side of the accommodation cell D12 in the transfer control flow path LF11. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a microfluidic chip that weighs and mixes a small amount of liquid.

  Conventionally, an automatic analyzer is known as a technique for automatically analyzing immune components contained in a specimen such as blood and body fluid. In this automatic analyzer, a sample is added to a reaction container containing a reagent, and a reaction occurring between the reagent and the reagent in the reaction container is optically detected. The amount of reagent required for analysis of a sample by this automatic analyzer is as small as several μl (microliter) to several ml (milliliter) for one sample. A technique that can further reduce the amount of reagent to be used has been awaited. In addition, the conventional automatic analyzer has a large amount of waste water for washing the dispensing nozzle for dispensing the sample and the reagent, and there is room for improvement in this point as well.

  As a technique that can solve such a situation, there is a microfluidic chip capable of weighing and mixing fluids by integrating elements necessary for analyzing a sample on a microchip (for example, Patent Documents). 1 and 2). Regarding this microfluidic chip, a technique of controlling the flow of fluid between flow paths by pressing an elastic member is also disclosed.

JP 2004-270935 A JP 2007-162899 A JP 2007-108087 A

  However, the microfluidic chip shown in Patent Documents 1 and 2 has a problem in that the apparatus configuration is complicated and the processing effort is large because the fluid flow control is performed while the elastic member is pressed. .

  The present invention has been made in view of the above, and an object of the present invention is to provide a microfluidic chip capable of controlling the flow of fluid with a simple mechanism and accurately weighing the fluid contained in the cell. And

  In order to solve the above-described problems and achieve the object, the microfluidic chip according to the present invention discharges a surplus amount of fluid that exceeds the accommodation volume of the fluid introduction port for introducing the fluid to be weighed and the weighing cell. A weighing cell having a fluid discharge port and weighing one volume of fluid; and one end connected to the weighing cell, the fluid weighed in the weighing cell being able to flow out from the one end; And a transfer control flow path for stopping the outflow of the fluid by a Laplace force acting in a direction opposite to the direction.

  In the microfluidic chip according to the present invention, in the above invention, the other end of the transfer control flow path is connected to a storage cell that stores the fluid weighed by the weighing cell. It has the exhaust port which discharges | emits the gas in this accommodation cell, It is characterized by the above-mentioned.

  In the microfluidic chip according to the present invention, in the above invention, the transfer control channel has a liquid reservoir formed by increasing a partial cross-sectional area in the middle of the transfer control channel, The outflow of the fluid is stopped by the Laplace force generated in an enlarged diameter region formed by a transfer control flow path and the liquid reservoir.

  In the microfluidic chip according to the present invention as set forth in the invention described above, the liquid reservoir has an external exhaust port communicating with the outside.

  The microfluidic chip according to the present invention is characterized in that, in the above invention, the liquid reservoir is connected to a plurality of the transfer control flow paths.

  In the microfluidic chip according to the present invention as set forth in the invention described above, the transfer control channel is formed such that at least a part of the inner wall surface is hydrophobic.

  The microfluidic chip according to the present invention is characterized in that, in the above invention, a sealing member for sealing the fluid discharge port and the exhaust port and / or the external exhaust port is provided.

  Moreover, the microfluidic chip according to the present invention is characterized in that, in the above invention, a fluid introduction port sealing member for sealing the fluid introduction port is further provided.

  According to the present invention, the flow of the fluid is stopped by the Laplace force applied to the transfer flow path connecting the cells, and the flow of the fluid can be canceled by a simple mechanism. And the liquid can be fed to the adjacent cell via the transfer channel.

FIG. 1 is a schematic diagram showing a schematic configuration of a microfluidic chip according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view showing a cross section taken along line AA of the microfluidic chip shown in FIG. FIG. 3 is a cross-sectional view showing a case where fluid is accommodated in the weighing cell shown in FIG. FIG. 4 is a cross-sectional view showing a configuration of a microfluidic chip that is a first modification of the first embodiment of the present invention. FIG. 5 is a cross-sectional view showing a configuration of a microfluidic chip that is a second modification of the first embodiment of the present invention. FIG. 6 is a schematic diagram showing a weighing and transfer method using the microfluidic chip according to the first embodiment of the present invention. FIG. 7 is a schematic diagram showing a configuration of a microfluidic chip that is a third modification of the first embodiment of the present invention. FIG. 8 is a schematic diagram showing a configuration of a microfluidic chip that is a fourth modification of the first embodiment of the present invention. FIG. 9 is a schematic diagram showing a schematic configuration of the microfluidic chip according to the second embodiment of the present invention. FIG. 10 is a cross-sectional view showing a cross section of the microfluidic chip shown in FIG. FIG. 11 is a cross-sectional view showing a case where fluid is accommodated in the weighing cell shown in FIG. FIG. 12 is a cross-sectional view showing a configuration of a microfluidic chip that is Modification 1 of Embodiment 2 of the present invention. FIG. 13: is sectional drawing which shows the structure of the microfluidic chip which is the modification 2 of Embodiment 2 of this invention. FIG. 14 is a cross-sectional view showing the configuration of a microfluidic chip that is a third modification of the second embodiment of the present invention. FIG. 15 is a cross-sectional view showing a configuration of a microfluidic chip that is a fourth modification of the second embodiment of the present invention. FIG. 16 is a schematic diagram showing a configuration of a microfluidic chip that is a fifth modification of the second embodiment of the present invention. FIG. 17 is a schematic diagram showing a configuration of a microfluidic chip that is a sixth modification of the second embodiment of the present invention.

  Hereinafter, an embodiment for implementing a microfluidic chip of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments and modifications illustrated below, and various modifications can be made without departing from the spirit of the present invention. In the description of the drawings, the same parts are denoted by the same reference numerals.

(Embodiment 1)
FIG. 1 is a schematic diagram showing a schematic configuration of a microfluidic chip according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a cross section taken along line AA of the microfluidic chip 1 shown in FIG. . The microfluidic chip 1 shown in FIGS. 1 and 2 is formed using an optically transparent material that transmits 80% or more of light, for example, glass including heat-resistant glass, synthetic resin such as cyclic olefin, polystyrene, etc. It has an introduction port 11a, a weighing cell D11 and a storage cell D12, a transfer control channel LF11, a fluid discharge port 12a and an exhaust port 13a, and the weighing cell D11 and the storage cell D12 are connected by a transfer control channel LF11.

  The fluid inlet 11a has an opening in the upper plane of the microfluidic chip 1 and communicates with the weighing cell D11. A fluid is fed into the weighing cell D11 by inserting a probe or the like into the fluid introduction port 11a and dispensing a fluid as a specimen or a reagent.

  Similar to the fluid introduction port 11a, the fluid discharge port 12a has an opening in the upper plane of the microfluidic chip 1 and communicates with the weighing cell D11. When the fluid is weighed, the weighing cell D11 can be filled with the fluid by discharging the gas and fluid in the weighing cell D11 from the fluid discharge port 12a, and the filled fluid is weighed. In addition, when introducing a fluid from the fluid discharge port 12a, the fluid introduction port 11a plays a role as a discharge port for discharging the gas and fluid in the weighing cell D11.

  The weighing cell D11 and the storage cell D12 are formed to have a predetermined volume. In particular, in the weighing cell D11, when the fed fluid is filled in the cell, it can be weighed with a predetermined volume. The cell shape may be circular or rectangular.

The transfer control flow path LF11 is preferably formed so that a cross-sectional area perpendicular to the fluid flow direction is 1 mm ² or less, and particularly preferably 0.1 mm ² or less. The fluid injected into the weighing cell D11 flows into the transfer control flow path LF11 by capillary action, but the force is in the direction opposite to the fluid flow direction in the enlarged diameter region at the boundary between the transfer control flow path LF11 and the containing cell D12. A Laplace force is generated, and the flow of the fluid is stopped by the Laplace force, and the fluid does not flow into the storage cell D12. Moreover, the gas in the transfer control flow path LF11, the weighing cell D11, and the storage cell D12 is discharged from the exhaust port 13a as the fluid flows. The fluid is weighed with the weighing cell D11, the transfer control flow path LF11, the fluid introduction port 11a, and the fluid discharge port 12a as weighing units, and the total amount of the filled fluid is targeted.

  Here, the case where the fluid is accommodated in the weighing cell D11 will be described with reference to FIG. FIG. 3 is a cross-sectional view showing a case where the fluid F1 is accommodated in the weighing cell D11. The fluid F1 dispensed from the fluid introduction port 11a enters the transfer control flow path LF11 by a capillary phenomenon, but by a Laplace force opposite to the flow direction applied to the end of the transfer control flow path LF11 on the accommodation cell D12 side. The flow of the fluid F1 is stopped. The fluid F1 is sequentially filled in the weighing cell D11 by this flow stop.

The cross-sectional area of the transfer control flow path LF11 is determined by the following expression (1). The Laplace force is determined by the surface tension of the fluid, the contact angle of the specimen, reagent, or reaction liquid with respect to the transfer channel, the channel width, and the channel depth, and suppresses the flow of the liquid due to the capillary force. Here, when γ is the surface tension, θ is the contact angle, w is the channel width, and h is the channel depth (equivalent to w if the cross section of the transfer channel is a circle), the following equation (1) Based on the determined Laplace force P, w and h constituting the cross-sectional area of the transfer control flow path LF11 are set. The Laplace force P is arbitrarily set.
P = 2γ (1 / w + 1 / h) Sinθ (1)

  Further, in the arrangement of the storage cell D12, the bottom of the storage cell D12 may not coincide with the bottom of the transfer control flow path. FIG. 4 is a cross-sectional view showing a configuration of a microfluidic chip 2 that is a first modification of the first embodiment of the present invention. In the microfluidic chip 2 shown in FIG. 4, the transfer control flow path LF11a is connected to the side surface of the storage cell D13, and a difference in height is provided between the bottom of the transfer control flow path LF11a and the bottom of the storage cell D13. Thereby, since the diameter-enlarged region is formed also in the bottom portion direction of the transfer control flow path LF11a at the end of the transfer control flow path LF11a on the accommodation cell D13 side, the effect of the Laplace force can be further ensured. . Here, as in FIGS. 2 and 3, the gas in the accommodation cell D13 is discharged to the outside through the exhaust port 13b.

  The upper part of the transfer control channel may be arranged so as to coincide with the upper part of the accommodation cell. FIG. 5 is a cross-sectional view showing a configuration of a microfluidic chip 2a that is a second modification of the first embodiment of the present invention. In the microfluidic chip 2a shown in FIG. 5, the transfer control flow path LF11b for connecting the weighing cell D11 and the storage cell D13a is arranged so that the upper part of the transfer control flow path LF11b and the upper part of the storage cell D13a coincide. . At the end of the transfer control flow path LF11b on the accommodation cell D13a side, the flow of the fluid F1 is stopped by the same effect as the Laplace force shown in FIG. When the fluid F1 stored and weighed in the weighing cell D11 is sent to the storage cell D13a, the gas inside the storage cell D13a is discharged to the outside from the exhaust port 13c. By providing the transfer control flow path LF11b on the upper side of the storage cell D13a, it is possible to minimize the fluid F1 that flows backward even when a reverse flow to the weighing cell D11 occurs due to an external force.

  Next, a weighing method and a transfer method for weighing the fluid F1 in the weighing cell D11 and transferring the weighed fluid F1 to the storage cell D12 will be described with reference to FIG. FIG. 6 is a schematic diagram showing a weighing and transfer method using the microfluidic chip 1 according to the first embodiment of the present invention.

  First, the fluid F1 to be dispensed is injected from the fluid introduction port 11a (FIG. 6A). When the fluid F1 is injected, the fluid F1 enters the transfer control flow path LF11 from the bottom of the weighing cell D11 by capillarity, the flow stops at the end on the accommodation cell D12 side due to Laplace force, and the fluid F1 enters the weighing cell D11. Is filled. The injection of the fluid F1 is continued until the fluid F1 is discharged from the fluid discharge port 12a for weighing (FIG. 6B).

  When the injection of the fluid F1 into the transfer control flow path LF11 and the weighing cell D11 is completed, the discharged fluid F1 is removed, and the fluid discharge port 12a is sealed by the sealing member 14a (FIG. 6C). By this sealing, the stored fluid F1 is stored in a predetermined amount in the weighing cell D11 and can be weighed. When only the fluid introduction port 11a and the exhaust port 13a are opened by sealing with the sealing member 14a, air is injected into the weighing cell D11 from the fluid introduction port 11a using a probe or the like, and the fluid F1 is pressed. . When the fluid F1 is pressed and the force in the flow direction of the fluid F1 exceeds the Laplace force applied to the transfer control flow path LF11, the flow stop due to the Laplace force is released, and the fluid F1 flows into the accommodation cell D12 ( FIG. 6 (d)). When the air pressure is continued and the fluid F1 accommodated in the weighing cell D11 is completely transferred to the accommodation cell D12, the fluid inlet 11a is sealed by the fluid inlet sealing member 14b (FIG. 6E).

  Whether or not to seal the fluid introduction port 11a shown in FIG. 6 (e) is arbitrary, but it is possible to prevent the back flow of the fluid F1 to the weighing cell D11 side by the internal pressure in the weighing cell D11. The fluid inlet 11a is preferably sealed with the sealing member 14b. Further, when the weighed fluid F1 is collected, it can be collected by sucking it with a pipette from the exhaust port 13a. Furthermore, the sealing member 14a may be a separate body or a single body.

  The above-described microfluidic chip makes it possible to reliably transfer the weighed fluid with a simple mechanism. In addition, unlike the microfluidic chip shown in Patent Documents 1 and 2, it is not necessary to form a part of the microfluidic chip with an elastic member or the like, so that the microfluidic chip can be created with a simple configuration. In addition, since the distribution control shown in Patent Document 3 uses a photoresponsive gel, it takes time to open and close the flow path. On the other hand, the microfluidic chip according to the present embodiment can transfer a fluid without requiring time for a photoresponsive reaction.

  Here, in the microfluidic chip 1 shown in FIG. 1, a plurality of weighing cells may be provided, and each weighed fluid may be mixed. FIG. 7 is a schematic diagram showing a configuration of a microfluidic chip 3 which is a third modification of the first embodiment of the present invention. The microfluidic chip 3 shown in FIG. 7 is provided with a plurality of weighing cells D14, D15, D16, D17, and each weighing cell is connected to a mixing cell M1 as a storage cell by a transfer control flow path LF12a, LF12b, LF12c, LF12d. is doing. Accordingly, the weighed fluids can be mixed by feeding the weighed fluids to the mixing cell M1. In addition, since each weighing cell D14, D15, D16, D17 is formed corresponding to the volume which should be measured, a shape or accommodation volume may differ.

  When the fluid is stored in each weighing cell D14, D15, D16, D17 in the flow shown in FIG. 6, the fluid discharge ports 12b to 12e are sealed, and air is injected from each fluid introduction port 11b to 11e to mix. Send to cell M1. At this time, the gas in the mixing cell M1 is discharged from the exhaust port 13d. Thereby, each fluid sent into the mixing cell M1 can be mixed. The weighing cells D14, D15, D16, D17 and the exhaust port 13d can be arranged at any position as long as processing is possible.

  Further, a plurality of mixing cells may be provided and mixed in stages. FIG. 8 is a schematic diagram showing a configuration of a microfluidic chip 4 that is a fourth modification of the first embodiment of the present invention. In the microfluidic chip 4 shown in FIG. 8, the mixing cells M2 and M3 are connected by the transfer control flow path LF13c, and the mixing cell M2 is connected to the weighing cells D18 and D19 via the transfer control flow paths LF13a and LF13b, and mixed. The cell M3 is connected to the weighing cell D20 via the transfer control flow path LF13d. The mixing cells M2 and M3 discharge the internal gas to the outside through the exhaust ports 13e and 13f.

  The fluids weighed in the weighing cells D18 and D19 are sent from the fluid introduction ports 11f and 11g by air to the mixing cell M2 to be mixed. The fluid mixed in the mixing cell M2 is stopped by the Laplace force applied to the transfer control flow path LF13c, and remains in the mixing cell M2. Further, after the fluid weighed in the weighing cell D20 is fed to the mixing cell M3, the fluid in the mixing cell M2 is fed to the mixing cell M3 from the fluid introduction port 11f and / or the fluid introduction port 11g, thereby weighing. Each of the fluids can be mixed stepwise. Here, the order of the fluid sent to the mixing cell M3 may send the fluid in the mixing cell M2 first.

  In addition, each fluid discharge port 12f-12h is sealed with a sealing member at the time of liquid feeding. In addition, the fluid introduction ports 11f to 11h may be sealed with a fluid introduction port sealing member after feeding. Further, when the fluid in the mixing cell M2 is fed, for example, when air is injected and pressed from the fluid introduction port 11f, the fluid introduction ports 11g and 11h and the fluid discharge ports 12f to 12h are sealed with the fluid introduction port. It is preferable that it is sealed with a stop member and a sealing member.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. FIG. 9 is a schematic diagram showing a schematic configuration of the microfluidic chip 5 according to the second embodiment of the present invention, and FIG. 10 is a cross-sectional view showing a cross section of the microfluidic chip 5 shown in FIG. is there. The microfluidic chip 5 shown in FIGS. 9 and 10 is an optically transparent material that transmits 80% or more of light, for example, glass including heat-resistant glass, synthetic resin such as cyclic olefin and polystyrene, as in the first embodiment. And has a fluid introduction port 21a, a weighing cell D21 and a storage cell D22, transfer control flow paths LF21a and LF21b, a liquid reservoir C21, a fluid discharge port 22a and an exhaust port 23a, and the weighing cell D21 and the storage cell D22 is connected by transfer control flow paths LF21a and LF21b via a liquid reservoir C21.

  The liquid reservoir C21 is provided between the transfer control flow path LF21a and the transfer control flow path LF21b so that the diameter in the direction perpendicular to the fluid flow direction is larger than that of the transfer control flow paths LF21a and LF21b. Is formed.

  Here, the case where the fluid F2 is accommodated in the weighing cell D21 will be described with reference to FIG. FIG. 11 is a cross-sectional view showing a case where the fluid F2 is accommodated in the weighing cell D21 shown in FIG. The fluid F2 accommodated in the weighing cell D21 flows into the transfer control flow path LF21a by capillary action, but the fluid F2 flowing through the transfer control flow path LF21a is at the contact point between the transfer control flow path LF21a and the liquid reservoir C21. The Laplace force is applied at each contact point due to the diameter expansion, and the flow of the fluid F2 is stopped. The fluid F2 dispensed from the fluid inlet 21a due to the suspension of the fluid is filled into the weighing cell D21 and the transfer control flow path LF21a.

  As in the first embodiment, a difference in height may be provided between the bottom of the transfer control flow path and the bottom of the accommodation cell. FIG. 12 is a cross-sectional view showing a configuration of a microfluidic chip 6 that is Modification 1 of Embodiment 2 of the present invention. In the microfluidic chip 6 shown in FIG. 12, the transfer control flow path LF21c is connected to the side surface portion of the storage cell D23, and a difference in height is provided between the bottom of the transfer control flow path LF21c and the bottom of the storage cell D23. Thereby, since the diameter-enlarged region is formed also in the bottom direction of the transfer control flow path LF21c, the effect of the Laplace force can be further ensured. In particular, even when the flow stop of the transfer control flow path LF21a is released by an external force, the flow can be stopped by the Laplace force applied to the transfer control flow path LF21c, so that errors in weighing can be minimized. is there. Moreover, it has the exhaust port 23b which discharges | emits the gas in the accommodation cell D23 similarly to the microfluidic chip 5 shown to FIG.

  Furthermore, the upper part of the transfer control channel may be arranged so as to coincide with the upper part of the accommodation cell. FIG. 13 is a cross-sectional view showing a configuration of a microfluidic chip 6a that is a second modification of the second embodiment of the present invention. The microfluidic chip 6a shown in FIG. 13 is arranged such that the transfer control flow path LF21d for connecting the liquid reservoir C21 and the storage cell D23a is aligned with the upper part of the transfer control flow path LF21d and the upper part of the storage cell D23a. The At the end of the transfer control flow path LF21d on the side of the accommodation cell D23a, the flow of the fluid F2 is stopped by the same effect as the Laplace force applied to the end of the transfer control flow path LF21a on the liquid reservoir C21 side. It is possible to stop the flow of the fluid stepwise and to feed the fluid, and even when a backflow to the weighing cell D21 occurs due to an external force, it is possible to minimize the backflowing fluid F2. . Note that the storage cell 23a has an exhaust port 23c for discharging the gas in the storage cell D23a, similarly to the microfluidic chip 6 shown in FIG.

  Moreover, you may provide the exhaust port which discharges | emits gas in the upper part of a liquid reservoir part. FIG. 14 is a cross-sectional view showing a configuration of a microfluidic chip 7 which is a third modification of the second embodiment of the present invention. The microfluidic chip 7 shown in FIG. 14 has an external exhaust port 24a that communicates with the upper part from the liquid reservoir C22. By the external exhaust port 24a, the gas in the microfluidic chip 7 can be discharged to the outside more efficiently, and the efficiency of the injection work is improved. When the fluid stored in the weighing cell D21 is transferred to the storage cell D22, the external exhaust port 24a is sealed with a sealing member.

  In particular, as shown in FIG. 15, it is effective when the weighing cells are provided adjacent to each other. FIG. 15 is a cross-sectional view showing a configuration of a microfluidic chip 8 that is a fourth modification of the second embodiment of the present invention. In the microfluidic chip 8 shown in FIG. 15, a weighing cell D21 is connected to a weighing cell D24 having a fluid inlet 25a and a fluid outlet 26a via transfer control channels LF21a and LF21b. At this time, for example, when the fluid F2 is stored in the weighing cell D21, when the fluid F3 is injected into the weighing cell D24 from the fluid introduction port 25a, the external exhaust port 24a causes the gas in the weighing cell D24 to flow outside. Take the role of discharging.

  Furthermore, the configuration of the second embodiment can be applied to the microfluidic chips 3 and 4 shown in FIGS. FIG. 16 is a schematic diagram showing a configuration of a microfluidic chip 9 which is a fifth modification of the second embodiment of the present invention, and FIG. 17 is a microfluidic chip which is a sixth modification of the second embodiment of the present invention. FIG. In the microfluidic chip 9 shown in FIG. 16, each weighing cell D25-28 is connected to the mixing cell M4 via transfer control flow paths LF22a-LF25a, LF22b-LF25b. Further, liquid reservoirs C23 to C26 are provided between the transfer control flow paths LF22a to LF25a, LF22b to LF25b, and an exhaust port 23d communicating with the upper part is formed at the center of the mixing cell M4. In addition, fluid introduction ports 21b to 21e and fluid discharge ports 22b to 22e are formed in each weighing cell D25 to 28, and the fluid stored in each weighing cell D25 to 28 can be weighed.

  With the configuration of the microfluidic chip 9 shown in FIG. 16, for example, when the fluid stored in the weighing cells D25 and 26 is fed to the mixing cell M4, the fluid stored in the mixing cell M4 is transferred to the transfer control flow path LF24b. , The flow is stopped by LF25b, and the fluids accommodated in the weighing cells D27, 28 are stopped by the transfer control flow paths LF24a, LF25a, and therefore mixed in the space formed by the liquid reservoirs C25, C26. Since the fluid stored in the cell M4 and the fluid stored in the weighing cells D27 and 28 do not come into contact with each other, the fluid can be mixed more reliably.

  Also, in the microfluidic chip 10 shown in FIG. 17, each fluid is processed by the liquid reservoirs C <b> 27 and C <b> 28 without contacting each fluid stored in the mixing cell M <b> 5 and each weighing cell D <b> 29 to 31. be able to. Therefore, the weighed fluid can be mixed stepwise without providing a plurality of mixing cells.

  In the microfluidic chip 10, each of the weighing cells D29 to D31 has fluid introduction ports 21f to 21h and fluid discharge ports 22f to 22h, and transfer control flow paths LF26a to LF26c, LF27a, via liquid reservoirs C27 and C28. The LF 27b communicates with the mixing cell M5. Further, the fluid injected into the weighing cells D29 and D30 is stopped by the Laplace force applied to the transfer control flow paths LF26a and LF26b, and the weighing cells D29 and D30 are filled with the fluid.

  Here, the liquid reservoir C27 has an external exhaust port 24b. By discharging the gas in the weighing cells D29 and D30 through the external exhaust port 24b, the exhaust efficiency in the weighing cells D29 and D30 is improved, and a more efficient injection process is possible. When the fluid stored in the weighing cell D29 and / or the weighing cell D30 is sent to the mixing cell M5, the external exhaust port 24b is sealed with a sealing member in addition to the fluid discharge ports 22f and 22g. Similarly, in the weighing cell D31, the fluid is injected from the fluid introduction port 21h and seals the fluid discharge port 22h when the liquid is fed. At this time, the fluid introduction ports 21f and 21g, the fluid discharge ports 22f and 22g, and the external exhaust port 24b are preferably sealed.

  When no fluid is stored in one of the weighing cell D29 or the weighing cell D30, for example, when the fluid is stored in the weighing cell D29, and when no fluid is stored in the weighing cell D30, the fluid is stored in the weighing cell D29. When the supplied fluid is fed to the mixing cell M5, it is preferable that the fluid inlet 21g and the fluid outlet 22g of the weighing cell D30 not accommodated are sealed by the fluid inlet sealing member. Furthermore, it is preferable that only the fluid introduction ports 21f to 21h and the exhaust ports 23e of the weighing cells D29 to D31 that perform liquid feeding are opened for transferring the fluid to the mixing cell M5.

  Since the microfluidic chip according to the second embodiment described above can be weighed and mixed without the fluid contained in each cell coming into contact, it is possible to perform more reliable processing. It can cope with typical processing.

  Further, for example, even when the flow resting force due to the Laplace force is released in the transfer control flow path LF21a of the microfluidic chip 5 shown in FIG. 9 by an external force, and a part of the fluid leaks into the liquid reservoir C21. Since the flow can be stopped by the Laplace force applied to the transfer control flow path LF21b, it is possible to minimize the influence on the weighing.

  In the first and second embodiments described above, it is preferable that the inner surface of the transfer control channel is formed so that at least a place where a Laplace force can be generated is hydrophobic. Further, the length of the flow path of the transfer control flow path may be any flow path length as long as it can be weighed, and the flow path may be bent.

  As described above, the microfluidic chip according to the present invention is useful when performing accurate weighing, and is particularly suitable for weighing and mixing in microanalysis.

1, 2, 2a, 3, 4, 5, 6, 6a, 7, 8, 9, 10 Microfluidic chips 11a to 11h, 21a to 21h Fluid inlets 12a to 12h, 22a to 22h Fluid outlets 13a to 13f, 23a-23e Exhaust port 14a Sealing member 14b Fluid inlet port sealing member 24a, 24b External exhaust port D11, D14-D21, D24-D31 Weighing cells D12, D13, D13a, D22, D23, D23a Receiving cells LF11, LF11a, LF11b, LF12a to LF12d, LF13a to LF13d, LF21a to LF21d, LF22a to LF27a, LF22b to LF27b Transfer control flow path C21 to C28 Liquid reservoir F1 to F3 Fluid M1 to M5 Mixed cell

Claims (8)

A weighing cell that has a fluid introduction port for introducing a fluid to be weighed and a fluid discharge port for discharging a surplus amount of fluid that exceeds the accommodation volume of the weighing cell;
One end is connected to the weighing cell, and a transfer control capable of flowing out the fluid weighed in the weighing cell from the one end and stopping the outflow of the fluid by a Laplace force acting in a direction opposite to the outflow direction. A microfluidic chip comprising a flow path. The other end of the transfer control flow path is connected to a storage cell that stores the fluid weighed by the weighing cell,
The microfluidic chip according to claim 1, wherein the storage cell has an exhaust port for discharging the gas in the storage cell. The transfer control channel has a liquid reservoir formed by increasing a partial cross-sectional area in the middle of the transfer control channel,
3. The microfluidic chip according to claim 1, wherein outflow of the fluid is stopped by the Laplace force generated in an enlarged diameter region formed by the transfer control flow path and the liquid reservoir.   4. The microfluidic chip according to claim 3, wherein the liquid reservoir has an external exhaust port communicating with the outside.   The microfluidic chip according to claim 1, wherein the liquid reservoir is connected to a plurality of the transfer control flow paths.   The microfluidic chip according to any one of claims 1 to 5, wherein the transfer control channel is formed so that at least a part of the inner wall surface is hydrophobic.   The microfluidic chip according to claim 1, further comprising a sealing member that seals the fluid discharge port and the exhaust port and / or the external exhaust port.   The microfluidic chip according to claim 7, further comprising a fluid introduction port sealing member that seals the fluid introduction port.

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