JP2010276430A - Micro fluid device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a micro fluid device for preventing a backward flow and a pulsation flow of a liquid sample when it is transmitted, and obtaining the stable flow rate accuracy of a liquid transmission to an analysis section. <P>SOLUTION: The micro fluid device 1 comprises: a sample supplying section 3 for introducing the liquid sample L containing a to-be-measured material into a substrate 2; the analysis section 4 for analyzing the liquid sample L; a waste liquid section 5 for accommodating the liquid sample L passing through the analysis section 4; a fluid flow path 6 for downwardly flowing the liquid sample L from the sample supplying section 3 to the waste liquid section 5; and a pump chamber 7 provided at a downstream area of the analysis section 4 on the substrate 2, and sucking the liquid sample L introduced into the sample supplying section 3 to the waste liquid section 5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a microfluidic device for analyzing a liquid sample containing a measurement substance such as a toxic substance contained in the environment as a measurement substance.

  In recent years, microfluidic devices manufactured by applying microfabrication technology such as semiconductors have been used in fields such as biochemistry and medicine. The microfluidic device is, for example, a sample supply unit that introduces a liquid sample containing a measurement substance into a substrate, an analysis unit that analyzes the liquid sample, and a waste liquid unit that contains the liquid sample that has passed through the analysis unit. A microanalysis device comprising a fluid flow path through which the liquid sample flows from the sample supply section to the waste liquid section.

  A liquid sample containing a measurement substance, for example, a toxic substance contained in the environment, a biological substance such as a nucleic acid / protein, or a fungus body, is introduced into the sample supply part of the microfluidic device and flows down to the analysis part. In the analysis unit, the measurement substance contained in the liquid sample is detected using, for example, an immunological technique based on an antigen-antibody reaction or a reaction based on a biochemical technique based on hybridization of a nucleic acid or the like.

Patent Document 1 discloses a conventional microfluidic device. As shown in FIG. 3, the microfluidic device includes a first substrate 3 and one surface side of the first substrate 3. And a second substrate 5 adhered to the substrate.
A first microchannel 11 as a fluid flow path is formed on the first substrate 3. An input port 7 as a sample supply unit and a pump chamber 13 whose upper part is opened to the atmosphere are provided on the first substrate 3. The discharge chamber 19 and the second microchannel 15 whose upper part is considered to function as an analysis part and open to the atmosphere, and the output port 9 as a waste liquid part are formed.
A valve membrane structure 20 that covers the pump chamber 13, the valve seat 17, and the discharge chamber 19 is stacked on the upper surface of the first substrate 3, and the valve membrane structure 20 includes a mold frame at the outer peripheral portion and a valve membrane inside the mold frame. 21, and the discharge chamber 19 communicates with the first microchannel 11 and the second microchannel 15.

  As shown in FIG. 3 of Patent Document 1, the pump chamber in the microfluidic device is provided upstream of the discharge chamber, and the transition of the liquid sample from the input port 7 to the output port 9 is as follows. It is implemented in this way.

  As shown in FIG. 6A, the liquid 25 is injected as a liquid sample from the input port 7, and the pump chamber 13 is filled with the liquid 25. Then, as shown in FIG. 6B, the valve membrane pushing portion 21 </ b> A at the top of the pump chamber 13 is pushed down by the pressing tool 22. Since the valve membrane feed part 21B is only self-adsorbing to the upper surface of the valve seat 17, the valve membrane feed part 21B rises from the valve seat 17 and a gap 27 is generated when a strong pressure is received. The liquid 25 inside the pump chamber 13 flows into the second microchannel 15 from the discharge chamber 19 through the gap 27 formed between the valve membrane flow section 21B and the valve seat 17 and moves to the output port 9. To do.

JP 2006-212473 A

In the microfluidic device described in Patent Document 1, when the liquid 25 is transferred from the pump chamber 13 to the discharge chamber 19, the liquid 25 may flow back to the first microchannel 11.
That is, since the flow resistance on the first microchannel 11 side is smaller than the self-adsorption force on the valve membrane feeding portion 21B and the upper surface of the valve seat 17, when the valve membrane pushing portion 21A is pushed down, most of the liquid 25 is discharged into the discharge chamber 19. Therefore, it does not flow into the first microchannel 11 but flows backward.

  Further, in the microfluidic device, after the liquid membrane 25 inside the pump chamber 13 is discharged into the discharge chamber 19 by pushing in the valve membrane pushing portion 21A at the top of the pump chamber 13, the pushed-in valve membrane pushing portion 21A is elastic. When the restoring force returns to the original state, a suction action is generated in the pump chamber 13 and the liquid 25 is sucked into the pump chamber 13. That is, in the microfluidic device, the liquid 25 is transferred to the discharge chamber 19 by continuously performing the operations of discharge and suction, so that a pulsating flow whose flow rate fluctuates when switching between the discharge action and the suction action occurs. Can do. If such a pulsating flow occurs, the speed at which the liquid sample flows down will not be uniform, and accuracy such as the reaction time in the analysis section will be lacking.

  Accordingly, an object of the present invention is to provide a microfluidic device that does not generate a backflow and a pulsating flow of a liquid sample at the time of liquid feeding and can obtain a stable flow rate accuracy for liquid feeding to an analysis unit.

In order to achieve the above object, the first characteristic configuration of the microfluidic device according to the present invention is:
A sample supply unit for introducing a liquid sample containing a measurement substance into the substrate, an analysis unit for analyzing the liquid sample, a waste liquid unit for storing the liquid sample that has passed through the analysis unit, and the waste liquid from the sample supply unit A fluid passage through which the liquid sample flows down to the part, and a pump chamber for sucking the liquid sample introduced into the sample supply part into the waste liquid part is provided downstream of the analysis part in the substrate. is there.

In this configuration, the pump chamber is provided downstream of the analysis section, and the liquid sample is sent from the sample supply section to the waste liquid section by the suction force of the pump action. The liquid is surely sent to the analysis unit without flowing back.
Furthermore, since the liquid sample is fed only by the suction action of the pump chamber, no pulsating flow is generated.

  The second characteristic configuration of the microfluidic device according to the present invention is that the pump chamber includes an elastic film that is elastically deformed by applying an external force and exhibits a pump action.

  According to this configuration, the liquid sample can be fed with a negative pressure in the pump chamber by elastic deformation of the elastic membrane. That is, the internal space in the pump chamber is expanded by introducing the liquid sample into the sample supply section in a state of being recessed by applying an external force to the elastic membrane and removing the external force to return the elastic membrane to the original flat state. As a result, a negative pressure is generated, and as a result, the liquid sample introduced into the sample supply section is sucked into the waste liquid section.

  Therefore, according to this configuration, it is possible to easily generate the suction force by the pump action by simply pushing the elastic membrane.

  According to a third characteristic configuration of the microfluidic device according to the present invention, the elastic film includes a magnetic body that is displaced by applying a magnetic force from the outside, and the elastic film is elastically deformed by the displacement of the magnetic body. In the point.

  According to this configuration, since the elastic film can be elastically deformed by attracting or repelling the magnetic body with a known magnetic force generator, the operation method for generating the pump action can be used. Various variations are born. As a result, the degree of freedom of design such as how to arrange the magnetic force generation device in order to cause a pump action in the microfluidic device is expanded.

  According to a fourth characteristic configuration of the microfluidic device according to the present invention, the fluid flow path communicates with an opening provided on a side surface of the pump chamber, and the elastic film is elastically deformed when the liquid sample is not sucked. The opening is closed.

If the opening is closed with an elastic film that is elastically deformed when the liquid sample is not sucked as in this configuration, the suction force is only between the opening of the opening and the return of the elastic film. Therefore, no matter what state the elastic film is elastically deformed, a constant suction force can always be generated.
As a result, regardless of the external force applied to the elastic membrane, a constant amount of liquid sample can be sent to the analysis unit at a constant flow rate, and the reaction start time in the analysis unit is uniformly aligned. Therefore, a highly accurate analysis value can be obtained.

  A fifth characteristic configuration of the microfluidic device according to the present invention is that the pump chamber includes a movable member that faces the pump chamber and that has a pumping action by moving out and out while sealing the pump chamber. It is in.

  According to this configuration, the liquid sample can be fed by setting the negative pressure in the pump chamber by the withdrawal operation of the movable member. That is, by introducing the liquid sample into the sample supply section with the movable member advanced to the pump chamber and withdrawing the movable member from the pump chamber, the internal space in the pump chamber is expanded and negative pressure is generated. As a result, the liquid sample introduced into the sample supply unit is sucked into the waste liquid unit.

  Therefore, according to this configuration, it is possible to easily generate the suction force by the pump action by simply retreating the movable member.

  A sixth characteristic configuration of the microfluidic device according to the present invention is that the movable member is a magnetic body that is displaced by applying a magnetic force from the outside.

  According to this structure, a movable member can be displaced by attracting or repelling the movable member which is a magnetic body using a well-known magnetic force generator. Therefore, various variations are born in the operation method for generating the pump action. As a result, the degree of freedom of design such as how to arrange the magnetic force generation device in order to cause a pump action in the microfluidic device is expanded.

  In a seventh characteristic configuration of the microfluidic device according to the present invention, the fluid flow path communicates with an opening provided on a side surface of the pump chamber, and the side surface of the movable member is used when the liquid sample is not sucked. The opening is closed.

If the opening is closed by the side surface of the movable member when the liquid sample is not sucked as in this configuration, the suction force is only from when the opening opens until the movable member returns to a predetermined position. Does not occur. For this reason, it is possible to always generate a constant suction force no matter where the movable member is advanced in the pump chamber.
As a result, regardless of the position of the movable member when the liquid sample is not sucked, a constant amount of the liquid sample can always be sent to the analysis unit at a constant flow rate. In addition, since the reaction start time in the analysis unit can be made uniform, a highly accurate analysis value can be obtained.

  An eighth characteristic configuration of the microfluidic device according to the present invention is that the waste liquid portion and the pump chamber are integrated.

  As in this configuration, the microfluidic device can be made compact by integrally configuring the waste liquid portion and the pump chamber.

It is a top view of the microfluidic device concerning a 1st embodiment. 1 is an exploded perspective view of a microfluidic device according to a first embodiment. It is the schematic of the longitudinal cross-section of the microfluidic device which concerns on 1st Embodiment. ((A) shows the state when the liquid sample is not sucked, and (b) shows the state when the liquid sample is sucked) It is process drawing explaining an example of the manufacturing method of the microfluidic device which concerns on 1st Embodiment. It is the schematic of the longitudinal cross-section of the microfluidic device which concerns on 2nd Embodiment. ((A) shows the state when the liquid sample is not sucked, and (b) shows the state when the liquid sample is sucked) It is the schematic of the longitudinal cross-section of the microfluidic device which concerns on other embodiment. ((A) shows the state when the liquid sample is not sucked, and (b) shows the state when the liquid sample is sucked) It is the schematic of the longitudinal cross-section of the microfluidic device which concerns on other embodiment. ((A) shows the state when the liquid sample is not sucked, and (b) shows the state when the liquid sample is sucked) It is the schematic of the longitudinal cross-section of the microfluidic device which concerns on other embodiment. ((A) shows the state when the liquid sample is not sucked, and (b) shows the state when the liquid sample is sucked) It is the schematic of the longitudinal cross-section of the microfluidic device which concerns on other embodiment. ((A) shows the state when the liquid sample is not sucked, and (b) shows the state when the liquid sample is sucked)

[First Embodiment]
1st Embodiment which concerns on the microfluidic device 1 of this invention is described based on FIGS. 1-3.
As shown in FIGS. 1 to 3, the microfluidic device 1 according to the first embodiment analyzes a sample supply unit 3 that introduces a liquid sample L containing a measurement substance into a substrate 2 and the liquid sample L. And a waste liquid part 5 that stores the liquid sample L that has passed through the analysis part 4, and a fluid flow path 6 through which the liquid sample L flows from the sample supply part 3 to the waste liquid part 5. Further, a pump chamber 7 for sucking the liquid sample L introduced into the sample supply unit 3 into the waste liquid unit 5 is provided in the substrate 2 downstream of the analysis unit 4. Details of each component will be described below.

(substrate)
The substrate 2 includes a first substrate 2a, a second substrate 2b, and a third substrate 2c. As a constituent material of the substrate 2, for example, polydimethylsiloxane (PDMS), glass, or silicon can be used. Examples of the bonding method include oxygen plasma treatment, anodic bonding, hydrogen fluoride bonding, and the like, which are appropriately selected according to the constituent materials to be used. For example, in the case of bonding between a PDMS substrate and a PDMS substrate, bonding between a PDMS substrate and a glass substrate, or bonding between a PDMS substrate and a glass substrate, bonding by oxygen plasma treatment, In the case of bonding to a silicon substrate or bonding between a silicon substrate and a silicon substrate, bonding is performed by anodic bonding, and in the case of bonding between a glass substrate and a glass substrate, bonding is performed by hydrogen fluoride bonding.

  In addition, any of a direct processing method and an indirect processing method may be applied as a method of performing fine processing on the substrate 2. Examples of the direct machining method include a mechanical cutting method using a fine machining drill or the like. On the other hand, examples of the indirect processing method include an injection molding method in which a fine structure is transferred using a mold corresponding to a desired structure.

(Sample supply unit)
The sample supply unit 3 is a through-hole penetrating in the thickness direction of the first substrate 2a, and functions as a chamber having an opening for injecting the liquid sample L containing the measurement substance with a pipette or the like. The sample supply unit 3 may have a volume that can store a desired amount of the liquid sample L to be analyzed.

(Analysis Department)
The analysis unit 4 functions as a chamber for performing a reaction for analyzing the measurement substance contained in the liquid sample L.

  As the configuration of the analysis unit 4, for example, a configuration based on an immunological technique based on an antigen-antibody reaction may be used as a binding pair assay, or a structure based on a biochemical technique based on hybridization of a known nucleic acid or the like Can also be used.

  When using an immunological technique, the analysis unit 4 is configured to enclose a binding substance that binds to a measurement substance contained in the liquid sample L to form a specific complex. The binding substance may be any reactive substance that reacts with the measurement substance and can detect and quantify the measurement substance. The binding substance is fixed to the surface of the member forming the analysis unit 4, or a bead or the like. A binding substance is supported on the immobilized substance.

As shown in FIG. 3, in the first embodiment of the present invention, a cylindrical recess 4a is formed in the analysis unit 4, and a plurality of immobilized substances 4b carrying a binding substance are placed in the cylindrical recess 4a. The structure to hold | maintain is illustrated. A slight gap 4c is provided between the cylindrical recess 4a and the second substrate 2b so that the liquid sample L can pass but the immobilization substance 4b cannot pass through. When the liquid sample L flows down the analysis unit 4 Further, the immobilization substance 4b is configured not to flow out from the analysis unit 4.
As the size of the cylindrical recess 4a, for example, in the substrate 2 having a thickness of 2 mm, a length of 50 mm, and a width of 40 mm, the depth of the first flow path portion 6a of the fluid flow path 6 is 100 μm. Examples include a configuration in which the wall thickness of the recess 4a is 1.5 mm, the inner diameter is 1 mm, the depth is 150 μm, and the gap 4c between the columnar recess 4a and the second substrate 2b is 50 μm.

(Waste liquid part)
The waste liquid part 5 functions as a chamber for storing the reacted liquid sample L that has passed through the analysis part 4. The waste liquid part 5 is a through-hole penetrating in the thickness direction of the first substrate 2a, and preferably has a volume sufficient to store the liquid sample L that has passed through the analysis part 4. In the first embodiment, the waste liquid section 5 and a pump chamber 7 described later are integrally configured so as to communicate with each other in the thickness direction of the substrate 2, so that the microfluidic device 1 can be made compact. Yes.

(Fluid flow path)
The fluid channel 6 is a channel through which the liquid sample L flows from the sample supply unit 3 to the waste liquid unit 5 by connecting the sample supply unit 3 to the waste liquid unit 5. The fluid flow path 6 includes a first flow path section 6a extending from the lower part of the sample supply section 3 in the lateral direction of the first substrate 2a, and a second flow path section extending from the first flow path section 6a in the thickness direction of the first substrate 2a. 6 b and a third flow path portion 6 c that extends in the lateral direction of the third substrate 2 c from the second flow path portion 6 b and opens to the side surface of the pump chamber 7.

(pump room)
The pump chamber 7 is a through hole penetrating in the thickness direction of the third substrate 2c, and is configured to include a tapered surface having a larger diameter toward the upper side and an elastic film 8 made of an elastic material such as rubber. The elastic film 8 is provided so as to cover the upper opening of the pump chamber 7 and in close contact with the periphery of the opening without any gap. The surface opposite to the side facing the pump chamber 7 is provided with a flat plate 9 containing a magnetic material (a magnetic body whose position is displaced by applying a magnetic force from the outside).

  As shown in FIG. 1, in the first embodiment, the channel C having the sample supply unit 3, the analysis unit 4, the waste liquid unit 5, the fluid flow path 6, and the pump chamber 7 is provided as the microfluidic device 1. 8 shows a configuration provided in parallel in the vertical direction. However, the number of channels C to be set is not limited to this.

(Details of liquid sample and analysis method)
The liquid sample L refers to a liquid sample containing or possibly containing a measurement substance to be analyzed. The liquid sample L may be derived from any source. For example, it can be obtained from environmental samples, cells, cultures, tissues, body fluids, urine, serum and biopsy samples.
Examples of environmental samples include soil collected from factory sites, water collected from rivers, and the like. Then, the sample collected from the environment is adjusted to be a liquid sample L having a viscosity that can flow down in the flow path formed in the microfluidic device 1.

  The measurement substance contained in the liquid sample L is captured by the binding of this measurement substance and a binding substance (described later) that can form a specific conjugate. The specific complex is the result of the binding pair assay. As described later, the immunochemical complex resulting from the antigen-antibody reaction, the complex resulting from the hybridization of complementary nucleic acids, etc. Is preferably exemplified.

  The measurement substance can be any substance such as chemical substances, polymers such as proteins, DNA fragments, microorganisms or viruses, fragments thereof, hormones, and the like. Specifically, substances that can cause environmental pollution such as toxic substances (PCB, dioxins) and oily substances (heavy oil) contained in soil, or pathogenic E. coli cells contained in river water, etc. Preferably exemplified.

  The binding substance means a substance capable of recognizing a measurement substance, that is, a substance having molecular recognition ability capable of selectively detecting a measurement substance having an affinity for the binding substance. Specifically, antigens, antibodies, DNA fragments, proteins, peptides and the like are preferably exemplified, but are not limited thereto. For example, the binding substances for PCB and dioxin as measurement substances are an anti-PCB antibody and an anti-dioxin antibody, respectively.

  As an immunochemical technique, for example, the presence of a measurement substance in the liquid sample L can be detected or quantitatively measured by applying an immunoassay technique using a solid phase method. In the so-called “sandwich method” known as an immunoassay, for example, a target measurement substance such as an antigen is sandwiched between a labeled antibody and an antibody (binding substance) immobilized on the surface of the immobilized substance. The analysis unit 4 can form a specific complex and capture the measurement substance.

By labeling an antibody or the like that forms a specific complex, the presence of the measurement substance can be detected or quantitatively measured.
The specific complex formed by the antigen-antibody reaction is detected as follows.
For example, by labeling an antibody with a fluorescent (luminescent) substance and detecting its fluorescence (luminescent) intensity directly, or by binding an enzyme to the antibody and performing an enzymatic reaction using a chemiluminescent substrate, optical changes can be detected. To do.

  As a result of the reaction when a fluorescently labeled antibody is used, a labeled substance is present in the specific complex produced depending on the amount of the measurement substance. Therefore, the measurement substance can be quantified by measuring the amount of the labeling substance. The quantification of the labeling substance can take various methods along with the type of the labeling substance. For example, the fluorescence intensity of the fluorescent substance is measured by a fluorescence measuring device. By comparing the measured label strength with the label strength when a known amount of “measurement substance” is measured, the amount of the measurement substance in the liquid sample L can be determined.

  As shown in FIG. 3, an apparatus for measuring fluorescence intensity is exemplified as the analyzing means 10 of the first embodiment. The label of the specific complex is excited by irradiation with a semiconductor laser from the excitation light irradiation means 10a, and the emitted fluorescence is collected by a microlens, and only the fluorescent component is transmitted by an optical interference filter, and the fluorescence measurement apparatus 10b is used. To detect. The detection is performed individually for each of the eight analysis units 4. The microfluidic device 1 may be configured to be slidable in order to quickly detect each analysis unit 4.

(Manufacturing method of microfluidic device)
Based on FIG. 4, a manufacturing method of the microfluidic device 1 when PDMS is used as a constituent material of the substrate 2 (first substrate 2a, second substrate 2b, third substrate 2c) will be described.

In the step (A), a first mold 11 having an inverted shape of the shape of the first substrate 2a and a second mold 12 having an inverted shape of the shape of the third substrate 2c are formed by a known photolithography method.
First, a silicon wafer S having a desired size is prepared. The silicon wafer S can be dried in advance or subjected to a desired pretreatment such as a surface treatment. Thereafter, an appropriate resist material (for example, negative photoresist SU-8) is spin-coated at a rotational speed of 500 rpm to 5000 rpm for several seconds to several tens of seconds and dried in an oven to form a resist film having a desired thickness. Form.

  Next, a mask is placed on the resist film, and exposure is performed through an appropriate exposure apparatus through the mask. The mask has a layout pattern corresponding to the shape (part) of the first substrate 2a and the third substrate 2c to be manufactured. Thereafter, development is performed in a suitable developer (for example, 1-methoxy-2-propylacetic acid), and the first mold 11 having resist protrusions R corresponding to the fine structures of the first substrate 2a and the third substrate 2c on the upper surface and The second mold 12 is formed. The second mold 12 is completed by installing a core N having a trapezoidal cross section on the formed resist protrusion R.

  Production of the first mold 11 and the second mold 12 may not be performed by the above-described photolithography method, but may be performed by a metal cutting method or the like.

  Next, in step (B), the PDMS prepolymer 13 deaerated to remove bubbles is poured onto the upper surfaces of the first mold 11 and the second mold 12 and cured, so that the first substrate 2a and the third substrate made of PDMS are cured. 2c is formed.

Next, in step (C), the molded first substrate 2a and third substrate 2c are peeled off from the first mold 11 and the second mold 12, respectively. If necessary, shaping processing such as trimming can be performed.
Further, a second substrate 2b made of PDMS having the same size as the first substrate 2a is prepared, and surface modification processing by oxygen plasma processing is performed on the first substrate 2a, the second substrate 2b, and the third substrate 2c. After the surface modification treatment, the elastic film 8 made of an elastic material such as rubber is pumped on the third substrate 2c on the surface of the fluid flow channel 6 opposite to the surface where the third flow channel portion 6c is formed. A flat plate 9 containing a magnetic material is provided on the surface of the elastic membrane 8 opposite to the side facing the pump chamber 7. The horizontal width of the flat plate 9 is set smaller than the minimum horizontal width of the pump chamber 7.

  In step (D), the first substrate 2a is disposed on the second substrate 2b, the third substrate 2c is disposed on the first substrate 2a, and these are pressed and joined together to supply the sample. The microfluidic device 1 is completed by forming the channel C through which the part 3, the analysis part 4, the fluid flow path 6, the pump chamber 7, and the waste liquid part 5 communicate.

(How to use microfluidic devices)
Based on FIG. 3, the usage method of the microfluidic device 1 is demonstrated.
The microfluidic device 1 according to the first embodiment includes a holding base (not shown) for holding the microfluidic device 1, a known magnetic force generator G including an electromagnet, and a microfluidic device (not illustrated) including an analyzing unit 10. Used in the system. In a state where the microfluidic device 1 is installed on the holding table, the magnetic force generator G is set below the waste liquid part 5.

  As shown in FIG. 3A, when a magnetic force is generated by applying an electric current to the magnetic force generator G to pull the flat plate 9 toward the magnetic force generator G, the flat plate 9 together with the elastic film 8 is in the pump chamber 7. Since the elastic membrane 8 is elastically deformed and is recessed inside the pump chamber 7 because it is drawn inside. Eventually, the flat plate 9 is brought into the pump chamber 7 until the opening 7a on the side surface of the pump chamber 7 communicating with the third flow path portion 6c of the flow path is just closed by the elastic film 8 that is elastically deformed. The liquid sample L is introduced into the sample supply unit 3 in this state. At this time, since the flow channel 6 is sealed when the liquid sample L is introduced into the sample supply unit 3, the liquid sample is located near the boundary between the sample supply unit 3 and the first flow channel unit 6a of the flow channel. L will stay.

  Next, as shown in FIG. 3B, when the magnetic force generator G is turned off and the generation of the magnetic force is stopped, the force to pull the flat plate 9 into the pump chamber 7 does not act. The elastic film 8 tries to return to the original flat state by the elastic restoring force. As a result, the internal space of the pump chamber 7 expands and negative pressure is generated, and the liquid sample L flows down to the analysis unit 4 and is sucked into the waste liquid unit 5 as it is.

  When the liquid sample L flows down to the analysis unit 4, a reaction for analyzing the measurement substance in the liquid sample L is started in the analysis unit 4. For example, the measurement substance in the liquid sample L reacts with the binding substance of the immobilized substance 4b held in the cylindrical recess 4a of the analysis unit 4, and the resulting signal is detected to detect the measurement substance. Can be detected and quantified. Specifically, for example, as described above in the section of “Details of liquid sample L and its analysis method”, a target measurement substance such as an antigen is labeled antibody and an antibody immobilized on the immobilization substance ( In the so-called “sandwich method” in which a specific complex is formed and captured by the analysis unit 4 by being sandwiched between a binding substance) and a labeled antibody labeled with a fluorescent (luminescent) substance The substance to be measured can be detected and quantified, for example, by detecting the fluorescence (luminescence) intensity with the excitation light irradiation means 10a and the fluorescence measuring device 10b.

  As described above, according to the configuration of the first embodiment, the pump chamber 7 is downstream of the analysis unit 4, and the liquid sample L is sent from the sample supply unit 3 to the waste liquid unit 5 by the suction force of the pump action. Therefore, the liquid sample L is reliably sent to the analysis unit 4 without flowing back through the fluid flow path 6. In addition, since the liquid sample L is fed only by the suction action of the pump chamber 7, no pulsating flow is generated.

Furthermore, according to the structure of 1st Embodiment, the inside of the pump chamber 7 can be made into a negative pressure by the elastic deformation of the elastic film 8, and the liquid sample L can be sent. In other words, the liquid sample L is introduced into the sample supply unit 3 in a state where the elastic film 8 is recessed by applying an external force, and the elastic film 8 is returned to the original flat state by removing the external force. The internal space is expanded to generate a negative pressure. As a result, the liquid sample L introduced into the sample supply unit 3 is sucked into the waste liquid unit 5.
Therefore, according to this configuration, it is possible to easily generate the suction force by the pump action by simply pushing the elastic film 8.

  Furthermore, according to the configuration of the first embodiment, the elastic film 8 can be elastically deformed by attracting or repelling the flat plate 9 containing a magnetic material with a known magnetic force generator G. Various variations are born in the operation method for generating the pump action. As a result, the degree of freedom in design such as how to arrange the magnetic force generator G in order to generate a pumping action in the microfluidic device having this configuration is expanded.

Further, as in the first embodiment, when the liquid sample L is not sucked, the opening 7a on the side surface of the pump chamber 7 is closed by the elastically deformed elastic film 8, so that the opening 7a is opened. Since the suction force is generated only until the elastic film 8 returns to the original state, it is possible to always generate a constant suction force no matter what state the elastic film 8 is elastically deformed. it can.
As a result, regardless of the strength of the external force applied to the elastic film 8, a constant flow rate and a constant amount of the liquid sample L can be sent to the analysis unit 4. Therefore, the reaction start time in the analysis unit 4 can be made uniform, and a highly accurate analysis value can be obtained.

[Second Embodiment]
Next, 2nd Embodiment which concerns on the microfluidic device 1 of this invention is described based on FIG.
In order to avoid overlapping description with the first embodiment, only the configuration different from that of the first embodiment and the method of using the same will be described, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

  As shown in FIGS. 5A and 5B, the pump chamber 7 in the second embodiment is a through-hole penetrating in the thickness direction of the third substrate 2c, faces the pump chamber 7, and is a pump. A movable member 14 having a pumping action is provided by moving in and out while sealing the chamber 7. The movable member 14 is a columnar magnetic body containing a magnetic material (a magnetic body whose position is displaced by applying a magnetic force from the outside). The width of the pump chamber 7 is set to be larger than the width of the waste liquid chamber, and a step portion 15 is formed from the pump chamber 7 to the waste liquid chamber. In addition, the opening part 7a which leads to the 3rd flow-path part 6c of a distribution flow path is provided in the lowest part of the pump chamber 7 side surface, and the lower end of the opening part 7a is flush with the step part 15.

  The microfluidic device 1 according to the second embodiment includes a holding base (not shown) for holding the microfluidic device 1, a known magnetic force generator G including an electromagnet, and a microfluidic device (not illustrated) including an analyzing unit 10. The magnetic force generator G is used above the movable member 14 in a state where the microfluidic device 1 is installed on a holding table.

As shown in FIG. 5A, the movable member 14 is installed on the step portion 15, and the liquid sample L is introduced into the sample supply unit 3 with the opening 7 a closed by the side surface of the movable member 14. At this time, since the flow channel 6 is sealed when the liquid sample L is introduced into the sample supply unit 3, the liquid sample is located near the boundary between the sample supply unit 3 and the first flow channel unit 6a of the flow channel. L will stay.
Then, as shown in FIG. 5 (b), when an electric current is passed through the magnetic force generator G to generate a magnetic force and the movable member 14 is drawn toward the upper magnetic force generator G, the pump chamber 7 As a result, the internal space is expanded and a negative pressure is generated, and the liquid sample L flows down to the analysis unit 4 and is sucked into the waste liquid unit 5 as it is.

  When the liquid sample L flows down to the analysis unit 4, as in the first embodiment, a reaction for analyzing the measurement substance contained in the liquid sample L is started in the analysis unit 4, and the measurement substance is detected and quantified. be able to.

  As described above, in the configuration of the second embodiment, the pump chamber 7 is downstream of the analysis unit 4 and the liquid sample L is sent from the sample supply unit 3 to the waste liquid unit 5 by the suction force of the pump action. Therefore, the liquid sample L is reliably sent to the analysis unit 4 without flowing back through the fluid flow path 6. In addition, since the liquid sample L is fed only by the suction action of the pump chamber 7, no pulsating flow is generated.

  Furthermore, according to the structure of 2nd Embodiment, the inside of the pump chamber 7 can be made into a negative pressure with the withdrawal operation | movement of the movable member 14, and the liquid sample L can be sent. That is, the liquid member L is introduced into the sample supply unit 3 with the movable member 14 advanced into the pump chamber 7, and the movable member 14 is withdrawn from the pump chamber 7, thereby expanding the internal space of the pump chamber 7. A negative pressure is generated, and as a result, the liquid sample L introduced into the sample supply unit 3 is sucked into the waste liquid unit 5. Therefore, according to this configuration, it is possible to easily generate the suction force by the pump action by simply retracting the movable member 14.

Furthermore, according to the structure of 2nd Embodiment, the movable member 14 can be displaced by attracting or repelling the movable member 14 which is a magnetic body using the well-known magnetic force generator G. Therefore, various variations are born in the operation method for generating the pump action. As a result, the degree of freedom in design such as how to arrange the magnetic force generator G in order to generate a pumping action in the microfluidic device having this configuration is expanded.

If the opening 7a is closed by the side surface of the movable member 14 when the liquid sample L is not aspirated as in the second embodiment, the movable member 14 is predetermined after the opening 7a is opened. The suction force is generated only until the position returns to the position. Therefore, even if the movable member 14 is advanced to any position in the pump chamber 7, a constant suction force can be always generated.
As a result, the liquid sample L can be always sent to the analysis unit 4 at a constant flow rate regardless of the position of the movable member 14 when the liquid sample L is not sucked. For this reason, the time of the reaction start in the analysis part 4 can be equalized, and a highly accurate analysis value can be obtained.

[Other Embodiments]
1. The magnetic force generator G in the first embodiment described above may not include an electromagnet. For example, as shown in FIG. 6, a normal ferrite magnet G is used, and the ferrite magnet G is disposed directly under the waste liquid chamber 5. After the elastic film 8 is elastically deformed, the ferrite magnet G is moved away, the application of magnetic force is stopped, and the elastic film 8 is returned by its elastic restoring force so as to achieve a pumping action.

2. As another configuration having a pumping action, for example, as shown in FIG. 7, a flat plate 9 not including a magnetic material is provided on an elastic film 8, and the flat plate 9 is provided with an appropriate columnar body 16 (a plunger of a DC solenoid or the like). Further, a pumping action may be achieved by pushing and releasing with a rod that can be moved by a stepping motor. Alternatively, as shown in FIG. 8, the elastic film 8 is elastically deformed by applying a seal 17 from above the third substrate 2 c so as to cover the flat plate 9 not containing a magnetic material, and then the seal 17 is peeled off. It is good also as a structure which has a pump effect | action by returning the elastic film 8 with the elastic restoring force.

3. As another configuration, for example, as shown in FIG. 9, the movable member 14 is made of a material that does not contain a magnetic material and is moved up and down by a stepping motor or the like provided in a microfluidic device system (not shown). You may comprise so that an effect | action may be show | played.

4). As another configuration of the substrate 2, an appropriate resin film may be used instead of the second substrate 2b, and the resin film may be adhered to the first substrate 2a.

  The microfluidic device of the present invention is a kind of so-called biochip, in which a structure such as a minute capillary fluid flow path or an analysis part as a reaction region connected to the flow path is formed in a substrate, and DNA It can be used for the purpose of detecting toxic substances and measurement substances contained in liquid samples, such as analysis devices, microelectrophoresis devices, microchromatography devices, and microsensors.

DESCRIPTION OF SYMBOLS 1 Microfluidic device 2 Substrate 3 Sample supply part 4 Analysis part 5 Waste liquid part 6 Fluid flow path 7 Pump chamber 8 Elastic film 9 Flat plate 14 Movable member L Liquid sample

Claims (8)

  A sample supply unit for introducing a liquid sample containing a measurement substance into the substrate, an analysis unit for analyzing the liquid sample, a waste liquid unit for storing the liquid sample that has passed through the analysis unit, and the waste liquid from the sample supply unit A fluid channel through which the liquid sample flows down, and a pump chamber for sucking the liquid sample introduced into the sample supply unit into the waste liquid unit is provided downstream of the analysis unit in the substrate device.   The microfluidic device according to claim 1, wherein the pump chamber is provided with an elastic film that is elastically deformed by an external force to exert a pump action.   The microfluidic device according to claim 2, wherein the elastic film includes a magnetic body whose position is displaced by applying a magnetic force from the outside, and the elastic film is elastically deformed by the displacement of the magnetic body.   4. The fluid passage according to claim 2, wherein the fluid channel communicates with an opening provided on a side surface of the pump chamber, and the opening is closed by the elastic film that is elastically deformed when the liquid sample is not sucked. Microfluidic device.   2. The microfluidic device according to claim 1, further comprising a movable member that faces the pump chamber and has a movable member that has a pumping action when the pump chamber is sealed out.   The microfluidic device according to claim 5, wherein the movable member is a magnetic body whose position is displaced by applying a magnetic force from the outside.   7. The fluid channel according to claim 5, wherein the fluid channel communicates with an opening provided on a side surface of the pump chamber, and the opening is closed by a side surface of the movable member when the liquid sample is not aspirated. Microfluidic device.   The microfluidic device according to claim 2, wherein the waste liquid part and the pump chamber are integrated.

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