JP5427871B2 - Micropump device and microfluidic device - Google Patents

Description

  The present invention relates to a micropump device used in a microfluidic device in which a microchannel is formed, and more specifically, a structure for generating a gas for driving a microfluidic by irradiation with light is provided. The present invention relates to a micropump device and a microfluidic device provided with the micropump device.

  In recent years, analysis apparatuses have been downsized in various fields. For example, in bedside diagnosis in which medical diagnosis is performed in the vicinity of a patient, there is a strong demand for downsizing of crystal inspection equipment. In addition, since analysis of environmental pollutants in the air, water, or soil needs to be performed outdoors, downsizing of analyzers is strongly demanded in such applications. Furthermore, a very small analytical instrument is also required when food safety is inspected in factories or sales locations.

  Microfluidic devices are attracting attention as meeting these needs. The microfluidic device has, for example, a substrate that is sized to be easily carried and handled by hand. In the substrate, a plurality of fine channels for conveying reagents, diluents, specimens, and the like are formed. In the substrate, a reagent storage unit, a sample supply unit, a diluent storage unit, a reaction chamber, a mixing unit, and the like are appropriately provided as portions connected to the fine flow path.

Since microfluidic devices are being miniaturized, the size of the substrate is usually about 1000 cm ² or less in plane area, and the thickness of the substrate is about 0.5 mm to 10 mm. Therefore, the diameter of the fine channel formed inside is usually very thin, about 5 μm to 1 mm. Here, when the flow path is flat, the diameter of the fine flow path is defined by the narrower width of the cross section of the flat flow path.

  Therefore, microfluids such as specimens, diluents, and reagents are transported through channels with a very small diameter as described above, so that the surface tension and fine flow of liquids are different from circuits in which normal liquids are fed. It is greatly affected by the wettability of the road walls. Therefore, various studies have been made on various parts of such a microfluidic device.

  In a microfluidic device, a drive source for transporting fluid is required as in other fluid circuits. Non-Patent Document 1 below shows a structure in which a micro liquid feeding pump arranged outside a microfluidic device is connected as a driving source of such a microfluidic device. Examples of the micro liquid feed pump include a syringe pump to which a micro syringe is attached.

  However, in a structure in which a syringe pump or the like is connected to the outside of the microfluidic device, an external micro liquid feed pump is required in addition to the microfluidic device. Therefore, when carrying, not only the microfluidic device but also the micro liquid feeding pump has to be operated, and during use, a complicated operation for connecting the two has been forced. In addition, even after use, the microfluidic pump had to be removed from the microfluidic device and the microfluidic pump had to be brought home.

In order to eliminate such complexity, a method of constructing a micropump in a substrate of a microfluidic device has been studied. Here, the micropump is a driving source that sends the microfluid into the fine channel as described above, and typically refers to a very small pump having a total volume of about 1 cm ³ or less. . For example, Patent Document 1 discloses a micropump having a diaphragm structure that is extremely miniaturized by a MEMS processing technique. Patent Document 2 below discloses a micropump that intermittently feeds liquid using a micro piston. Patent Document 3 below discloses a pump that feeds liquid by a method of generating an electroosmotic flow on a fine channel. Patent Document 4 below discloses a micropump comprising a hydrogen pump using a solid electrolyte.

  On the other hand, Patent Document 5 below discloses a micropump in which a micropump chamber configured in a substrate is filled with a material that generates gas by heat or light. Here, gas is generated by applying thermal energy or irradiating light to a material that generates gas by heat or light disposed in the micropump chamber. Then, the microfluid in the fine channel is fed by the pressure of the generated gas. Patent Document 5 discloses a polyoxyalkylene resin having an oxygen content of 15 to 55% by weight as a material that generates gas by heat or light.

"Science" (1998, 282, 484)

JP 2001-132646 A JP 2002-021715 A Japanese Patent Laid-Open No. 10-10088 USP 3,489,670 JP 2005-297102 A

  The various micropumps described in Patent Documents 1 to 4 have a complicated structure and are difficult to reduce in size. In particular, the pumps described in Patent Documents 1 and 2 using a diaphragm structure or a micro piston have a mechanical structure, so that it is difficult to reduce the size, and pulsation occurs in the microfluid being fed. There was a problem.

  On the other hand, as described in Patent Document 3, a pump that generates an electroosmotic flow needs to apply a high voltage, and therefore requires a separate high voltage power source.

  On the other hand, in the hydrogen pump using the solid electrolyte described in Patent Document 4, it is difficult to assemble, and it is difficult to route the conductive wire and the gas flow path. Therefore, many pumps are installed in the substrate of the microfluidic device. It was difficult to mount to the density.

  On the other hand, in the micropump described in Patent Document 5, a material that generates gas by heat or light generates gas by heating or light irradiation, and thus does not require a complicated mechanical structure. No voltage application is required. Therefore, simplification and miniaturization of the structure of the micropump can be promoted. Moreover, since it is only necessary to form a micropump chamber that is filled with a material that generates gas by heat or light, the microfluidic device can be easily processed into a substrate.

  However, in the micropump described in Patent Document 5, the micropump is configured using a polyoxyalkylene resin having an oxygen content of 15 to 55% by weight. Even if the micropump is actually heated or irradiated with light. Therefore, it is difficult to obtain a sufficient gas pressure, and therefore there is a limit to miniaturization of the micropump. That is, since the efficiency is not sufficient, it is necessary to fill a relatively large micropump chamber with a relatively large amount of gas generating material, and it is difficult to reduce the size of the micropump. Moreover, although the said material generate | occur | produces gas by heating and irradiation of light, since the responsiveness is not enough, it was difficult to obtain a big gas pressure instantly.

  An object of the present invention is to provide a micropump device that can be configured in a very small size and easily in a substrate of a microfluidic device and that has excellent liquid feeding efficiency, and the micropump device, in view of the above-described state of the prior art. It is to provide a microfluidic device.

According to the present invention, there is provided a micropump device used in a microfluidic device in which a microchannel is formed in a substrate, wherein a gas generation chamber is formed in the substrate, and the gas generation chamber faces the gas generation chamber. an optical window provided in one surface of the substrate is housed in the gas generating chamber includes a support member, and a photoresponsive gas-generating resin composition is attached to the support member, the light through the optical window And a photoresponsive gas generating member that generates gas when irradiated with, wherein the support member of the photoresponsive gas generating member is formed of a porous member or a nonwoven fabric, and in the gas generating chamber, A micropump device is provided, wherein the micropump device is provided on a surface opposite to the optical window of the photoresponsive gas generating member, and includes a reflecting member that reflects light emitted from the optical window. It is.

  In the present invention, the reflection member is preferably made of a metal foil. In this case, the reflection member can be made of a metal foil that is easily available.

In the micropump device, preferably, an air layer is formed between the photoresponsive gas generating member and the inner surface of the optical window in the gas generating chamber. In this case, the gas generated from the photoresponsive gas generating member quickly diffuses into the gas generating chamber through the air layer between the photoresponsive gas generating member and the inner surface of the optical window, and serves as a micropump. Start-up performance is improved. As a measure for making such a structure, for example, a method of adhering and fixing the photoresponsive gas generating member to the inner surface of the gas generating chamber opposite to the optical window can be adopted.

  In the micropump device according to the present invention, preferably, the photoresponsive gas generating member and the optical window are in point contact at a number of points in the gas generating chamber. In this case, a space is formed between the photoresponsive gas generating member and the optical window except for the portion in point contact, so that the gas is promptly introduced into the space and the gas is generated. The indoor pressure is quickly increased.

  In the present invention, the photoresponsive gas generating resin composition preferably includes a binder resin and a gas generating agent that generates a gas when irradiated with light. In this case, since the binder resin is used as a matrix, the photoresponsive gas generating resin composition can be easily attached or impregnated to the support member. Further, the gas generating agent is preferably an azo compound or an azide compound. In that case, the azo compound or the azide compound is decomposed by light irradiation, and gas is rapidly generated.

  The micropump device according to the present invention may be provided in the microfluidic device substrate, or may be separately configured and used in combination with the microfluidic device at the time of use by means such as adhesive bonding or pressure welding. The gas released from the micropump device drives the liquid in the microchannel of the microfluidic device by its excluded volume effect, and functions as a micropump.

  A microfluidic device according to the present invention has a micro flow channel in which a micro fluid is conveyed, a measurement cell connected to the micro flow channel, and a gas for driving the micro fluid in the micro flow channel. A substrate provided with a gas generation chamber for generating, and a micropump device of the present invention configured using the gas generation chamber of the substrate.

  In the micropump device according to the present invention, a reflecting member is arranged on the surface of the photoresponsive gas generating member on the side opposite to the optical window in the gas generating chamber, thereby reflecting the light emitted from the optical window. Is done. Therefore, the generation of gas in the photoresponsive gas generating member is promoted using the light reflected by the reflecting member. Therefore, the liquid feeding efficiency of the micropump device can be effectively increased.

  Therefore, according to the present invention, it is possible to provide a micropump device that is small but excellent in liquid feeding efficiency. For example, the microfluidic device that constitutes the micropump device can be miniaturized.

(A) And (b) is the schematic front sectional drawing of the microfluidic device which concerns on one Embodiment of this invention, and the partial front sectional drawing which expands and shows the micropump apparatus part of this microfluidic device. It is a partial front sectional view showing a modification of the micropump device of the present invention. It is a figure which shows the relationship between the irradiation energy at the time of irradiating the micro pump apparatus of Example 1 with an ultraviolet-ray, and a flow volume. In the micropump apparatus of Examples 1, 2 and Comparative Example 1, it is a figure which shows the relationship between the time which irradiated the ultraviolet-ray, and a volume flow volume.

  Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention with reference to the drawings.

  1A and 1B are a schematic front sectional view of a microfluidic device according to an embodiment of the present invention and a partially cutaway enlarged front sectional view showing a structure of a micropump constituted by the microfluidic device. is there.

  As shown in FIG. 1A, the microfluidic device 1 has a substrate 2 formed by laminating a plurality of plates. The substrate 2 includes a base plate 3, intermediate plates 4 to 6 stacked on the base plate 3, and a top plate 7 stacked on the intermediate plate 6. Note that the laminated structure of the substrate 2 is not limited to this.

  A plurality of fine channels 8 and 9 are provided in the substrate 2. A reagent storage unit and a sample supply unit (not shown) are connected to the fine channel 9. A micro pump chamber 10 is connected to the fine channel 8. As shown in FIGS. 1A and 1B, the micropump chamber 10 is formed in the substrate 2. More specifically, in this embodiment, the base plate 3 is provided with a gas generation chamber 11 opened on the upper surface of the base plate 3. An optical window 12 is provided on the lower surface of the gas generation chamber 11. The optical window 12 is made of a material that transmits light for generating light when the photoresponsive gas generating resin composition described later is irradiated with light.

  In the present embodiment, the base plate 3 is made of a transparent member, and is formed integrally with the base plate 3 by the transparent member constituting the base plate 3. As such a transparent member, glass or a synthetic resin having transparency can be used, and the material is not particularly limited.

  The materials constituting the intermediate plates 4 to 6 and the top plate 7 other than the base plate 3 of the substrate 2 can also be formed of an appropriate material such as synthetic resin.

  On the other hand, the optical window 12 may be formed of a separate member from the base plate 3. That is, an opening may be provided in a part of the base plate 3 and a transparent member constituting the optical window 12 may be fixed to the opening so as to hermetically seal the gas generation chamber 11. In such a configuration, stray light can be prevented by coloring the base plate, and even when a large number of micropumps are arranged, each one can be reliably controlled without malfunction.

  Further, in the base plate 3, the gas generation chamber 11 is opened downward, and a transparent plate may be further laminated on the lower surface of the base plate 3 to form the optical window 12.

  At this time, the transparent plate forming the optical window may be painted or film-laminated for the purpose of shielding light other than the optical window.

  The gas generation chamber 11 is open on the upper surface of the base plate 3. A photoresponsive gas generating member 13 is accommodated in the gas generating chamber 11.

  The planar shape of the gas generation chamber 11 is not particularly limited, and may be an appropriate shape such as a circle or a rectangle. The depth of the gas generation chamber 11 is not particularly limited as long as the photoresponsive gas generation member 13 can be accommodated.

Usually, the size of the gas generation chamber 11 needs to constitute a small micropump, so that it is desirable that the plane area is about 400 mm ² or less and the depth is about 0.5 mm to 10 mm. In particular, when the power of the micropump is required, a plurality of gas generation chambers can be connected and used.

  The photoresponsive gas generating member 13 includes a photoresponsive gas generating resin composition that generates gas upon irradiation with light, and a support member to which the photoresponsive gas generating resin composition is attached.

  The photoresponsive gas generating resin composition may be any suitable photoresponsive gas generating resin composition that generates gas when irradiated with light, and is not particularly limited. Specific examples of such a photoresponsive gas generating resin composition will be described in detail later.

The photoresponsive gas generating resin composition is attached to the surface of the support member. Here, the supporting member can be used that obtained by rapidly releasing gas generated supporting support member.

  In this embodiment, the support member is made of cotton. That is, in the cotton which is a fibrous member, a large number of fibers are gathered and intertwined, and the gas generated from the gap between the fibers is quickly released to the outside. The photoresponsive gas generating resin composition is impregnated and attached to cotton so that the photoresponsive gas generating resin composition is attached to the surface of each fiber of the cotton. In this case, in the photoresponsive gas generating member 13, the light with which the gaps between the cotton fibers remain even when the photoresponsive gas generating resin composition adheres to the cotton constituting the support member. A responsive gas generating resin composition is adhered. Therefore, when gas is generated by light irradiation, the gas is promptly released to the outside through the gap.

  In this embodiment, cotton is used as the support member of the photoresponsive gas generating member, but other fibrous members other than cotton may be used. That is, an appropriate fibrous member in which glass fibers, synthetic fibers such as PET (polyethylene terephthalate) and acrylic, pulp fibers, metal fibers, and the like are gathered and intertwined can be used as the support member.

  In addition to the fibrous member, various porous members including not only the fibrous member but also the fibrous member can be used as the support member as long as the generated gas can be quickly released to the outside. Here, the porous member widely includes a member having a large number of holes connected to the outer surface, and a member having a gap between fibers connected to the outside, such as cotton, is also included in the porous member. I will do it.

  Therefore, in addition to the above fibrous member, a large number of holes are formed from the inside to the outer surface. For example, sponges, foam-breaking foams, porous gels, particle fusion bodies, gas pressure-assisted thickening moldings Porous materials such as honeycomb structures, cylindrical beads, and folded chips can also be suitably used as the porous member constituting the support member.

  The material of the support member is not particularly limited, and various inorganic materials or organic materials can be used. Examples of such inorganic materials include glass, ceramic, metal, or metal oxide, and examples of organic materials include polyolefin, polyurethane, polyester, nylon, cellulose, acetal resin, acrylic, PET (polyethylene terephthalate), polyamide, or polyimide. Can be used.

  The support member is preferably made of a porous member including the fibrous member. More preferably, the hole is opposite to the side on which the optical window 12 is provided from the surface on the optical window 12 side. A porous member in which gas flow paths such as continuous pores connected to the side surface are present as holes is desirable. In that case, the heat generated outside is released to the fine channel 8 side more quickly.

  The support member is preferably a porous member, but may be formed of a nonwoven fabric. Compared to the case where only the photoresponsive gas generating resin composition is filled in the gas generating chamber by attaching the photoresponsive gas generating resin composition to the surface of the nonwoven fabric, the photoresponsive gas generating resin composition The surface area per unit volume of the object can be increased, thereby increasing the gas generation efficiency.

  In the micropump device 10 of the present embodiment, the photoresponsive gas generating member 13 has a configuration in which the photoresponsive gas generating resin composition is attached to the support member. In other words, the light-responsive gas generating member 13 is released from the outer surface. Therefore, compared with the case where the lump of the photoresponsive gas generating resin composition is simply stored, the gas generation efficiency can be dramatically increased, for example, 10 times or more.

  As said photoresponsive gas generating resin composition, the appropriate composition which generate | occur | produces gas by irradiation of light can be used. Such a photoresponsive gas generating resin composition is not particularly limited, but preferably a composition containing a binder resin and a gas generating agent that generates a gas upon irradiation with light. By using the binder resin, the photoresponsive gas generating resin composition can be easily attached to the surface of the support member. Such a binder resin is not particularly limited, and polymer materials such as polyester, poly (meth) acrylate, polyethylene, polypropylene, polystyrene, polyether, polyurethane, polycarbonate, polyamide, and polyimide can be used. Moreover, you may use these copolymers and compounding compositions. The ultraviolet light absorption band of the binder resin is preferably shorter than the ultraviolet light absorption band of the gas generating agent or photosensitizer.

  Further, the gas generating agent that generates gas when irradiated with light is not particularly limited. For example, an azo compound, an azide compound, a polyoxyalkylene resin, or a combination of a photo acid generator and sodium hydrogen carbonate, etc. Is used. Preferably, an azo compound or an azide compound is preferably used because of high gas generation efficiency.

  Examples of the azo compound include 2,2′-azobis- (N-butyl-2-methylpropionamide), 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl)]. -2-hydroxyethyl] propionamide}, 2,2′-azobis {2-methyl-N- [2- (1-hydroxybutyl)] propionamide}, 2,2′-azobis [2-methyl-N— (2-hydroxyethyl) propionamide], 2,2′-azobis [N- (2-propenyl) -2-methylpropionamide], 2,2′-azobis (N-butyl-2-methylpropionamide), 2,2′-azobis (N-cyclohexyl-2-methylpropionamide), 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] diha Drochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] disulfate Dihydrolate, 2,2′-azobis [2- (3,4,5,6-tetrahydropyrimidin-2-yl) propane] dihydrochloride, 2,2′-azobis {2- [1- (2 -Hydroxyethyl) -2-imidazolin-2-yl] propane} dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane], 2,2′-azobis (2-methyl) Propionamidine) hydrochloride, 2,2′-azobis (2-aminopropane) dihydrochloride, 2,2′-azobis [N- (2-carb Boxyacyl) -2-methyl-propionamidine], 2,2′-azobis {2- [N- (2-carboxyethyl) amidyne] propane}, 2,2′-azobis (2-methylpropionamidoxime), Dimethyl 2,2′-azobis (2-methylpropionate), dimethyl 2,2′-azobisisobutyrate, 4,4′-azobis (4-cyancarbonic acid), 4,4′-azobis (4 -Cyanopentanoic acid), 2,2'-azobis (2,4,4-trimethylpentane) and the like. Among them, 2,2′-azobis- (N-butyl-2-methylpropionamide), 2,2′-azobis (N-butyl-2-methylpropionamide), 2,2′-azobis (N-cyclohexyl-) 2-methylpropionamide) is preferred. These azo compounds generate nitrogen gas when stimulated by light, heat, or the like.

  Examples of the azide compound include 3-azidomethyl-3-methyloxetane, terephthalazide, p-tert-butylbenzazide; and glycidyl azide polymer obtained by ring-opening polymerization of 3-azidomethyl-3-methyloxetane. Examples thereof include a polymer having an azide group.

  The azo compounds and azide compounds are decomposed not only by light irradiation but also by heat and generate gas. Therefore, when an azo compound or azide compound is used, not only light irradiation but also heating is performed. In combination, gas may be generated.

  Examples of the photoacid generator include bis (cyclohexylsulfonyl) diazomethane, bis (t-butylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, triphenylsulfonium, trifluoromethanesulfonate, Diazodisulfone and triphenylsulfonium photoacid generators such as dimethyl-4-methylphenylsulfonium, trifluoromethanesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium, p-toluenesulfonate Etc. can be used.

  In addition, the photoresponsive gas generating resin composition may contain a known sensitizer in order to enhance the responsiveness by light irradiation. Examples of such sensitizers include acetophenones, benzophenone, Michler's ketone, benzyl, benzoin, benzoin ether, benzyldimethyl ketal, benzoyl benzoate, α-acyloxime ester, tetramethylthiuram monosulfide, thioxanthone, aliphatic amine, aromatic amine Amines containing aromatic groups, those in which nitrogen is part of the ring system, such as piperidine, allylthiourea, O-tolylthiourea, sodium diethyldithiophosphate, soluble salts of aromatic sulfinic acids, N, N-disubstituted -P-aminobenzonitrile compounds, tri-n-butylphosphine, N-nitrosohydroxylamine derivatives, oxazolidine compounds, tetrahydro-1,3-oxazine compounds, formaldehyde or acetaldehyde and diamine Compounds, anthracene (or derivatives thereof), xanthine, N- phenylglycine, phthalocyanine, naphthocyanine, cyanine dyes porphyrins (or derivatives thereof) such as thiocyanine like. These sensitizers may be used independently and 2 or more types may be used together.

The blending ratio of the binder resin and the gas generating agent in the photoresponsive gas generating resin composition is not particularly limited, but the gas generating agent is used as an amount that generates sufficient gas with respect to 100 parts by weight of the binder resin. It is preferable to mix in the range of 400 parts by weight. If it is less than 40 parts, it is difficult to generate a sufficient amount of gas, and if it exceeds 400 parts by weight, the photoresponsive gas generating resin composition becomes brittle, and small pieces of the photoresponsive gas generating resin composition block the gas flow path. May end up.

  Moreover, when using the said sensitizer, the mixture ratio of a sensitizer is although it does not specifically limit, In order to fully obtain a sensitizing effect | action, it is 0.1-10 weight with respect to 100 weight part of said gas generating agents. The range may be about a part. If the amount is less than 0.1 parts by weight, sufficient sensitizing action may not be obtained, and if it exceeds 10 parts by weight, the sensitizing action may be saturated.

  Looking at the gas generation characteristics of these gas generating agents as micropumps, the amount of gas generated is proportional to the light irradiation time, the amount of gas generated is proportional to the amount of gas generated after a certain period of time. Various characteristics such as those that rapidly increase are seen. In producing a micropump, it is effective to combine these characteristics well.

  The light used in the present invention is not particularly limited as long as it is a wavelength at which the photoresponsive gas generating agent or the photosensitizer has absorption, and preferably has a wavelength of 10 to 400 nm and a wavelength of 400 to nearly 400. 420 nm blue light is preferred. More preferably, the ultraviolet light is 300 to 400 nm.

  The photoresponsive gas generating member 13 has a form in which the photoresponsive gas generating resin composition is attached to the surface of the support member. Preferably, as shown in FIG. It is desirable that an air layer 14 be formed between the responsive gas generating member 13 and the optical window 12. When the air layer 14 is formed, the generated gas is quickly discharged to the fine flow path 8 side through the space of the air layer 14. More desirably, as shown in FIG. 1B, an air layer 14 provided between the optical window 12 and the photoresponsive gas generating member 13 is connected to a through hole 4 a provided in the intermediate plate 4. A gas flow path 15 is formed outside the side surface of the photoresponsive gas generating member 13. For this purpose, the plane area of the photoresponsive gas generating member 13 is preferably smaller than the plane area of the gas generating chamber 11.

  In the present embodiment, the surface of the photoresponsive gas generating member 13 on the side of the optical window 12 is provided with a large number of irregularities, whereby the volume of the air layer 14 is increased. Therefore, it is desirable to provide such unevenness.

  In the present embodiment, the reflecting member 17 is provided on the surface of the photoresponsive gas generating member 13 opposite to the optical window 12. The reflection member 17 is made of an appropriate reflective material that reflects the light emitted from the optical window 12. As such a reflective material, a metal, a mirror, or the like can be used. However, a metal foil, a metal vapor-deposited film, or the like can be used because it is preferably thin and can reduce the height of the microfluidic device. Preferably, a metal foil such as an aluminum foil which is excellent in reflectivity and inexpensive is preferably used. It is also possible to form a thinner reflective layer by evaporating an appropriate metal or alloy such as Al.

  The thickness of the reflecting member 17 is not particularly limited, but is preferably thinner. When made of metal foil, the thickness of the reflecting member 17 is about 1 μm to 500 μm. When the reflecting member 17 is formed by a thin film formed by a thin film forming method such as a vapor deposition film, the thickness is about 1 μm or less. That's fine.

  In addition, it is necessary to form the through-hole 17a in the reflection member 17. The through hole 17 a is provided at a position overlapping the discharge hole 16. By forming the through hole 17a, the generated gas can be discharged to the through hole 4a via the through hole 17a. The through hole 4 a is formed in the intermediate plate 4 and continues to the fine flow path 8. The fine channel 8 is formed by providing a through opening in the intermediate plate 5 according to the channel width, and the through opening is closed by the intermediate plate 4 and the upper intermediate plate 6 below. Thus, a fine channel 8 is formed. The fine channel 8 is connected to a connection through hole 6 a provided in the intermediate plate 6. The connection through-hole 6a is open to the fine channel 9. The fine channel 9 is provided by forming a recess corresponding to the planar shape of the fine channel 9 on the lower surface of the top plate 7.

  As described above, in the microfluidic device, the width of the microchannel is usually as small as about 5 μm to 1 mm, and therefore the microfluid sent through the microchannel is between the inner surface of the substrate 2. It is greatly affected by surface tension and is also greatly affected by capillary action. Therefore, the microfluid exhibits different behavior from a fluid circuit having a normal large flow path. In such a microfluidic device 1, a part of the length of the channel occupies the entire area of the cross section of the channel, but there is an air layer before and after the fluid, that is, the microfluid is liquid. It can be delivered in the form of drops. In such a case, the droplets in the microchannel are quickly transported due to the excluded volume effect of the gas that flows out from the micropump device 10. In this case, it is desirable that the pressure of the gas in the micropump device 10 rapidly increases in order to quickly send the microfluid.

  In the micropump device 10 of the present embodiment, as described above, the photoresponsive gas generating member 13 has a structure in which the photoresponsive gas generating resin composition is attached to the support member, and the gas is quickly released to the outside. Therefore, when gas is generated by light irradiation, the gas pressure can be rapidly increased. In addition, since the reflection member 17 is provided, light is effectively used, and the liquid feeding efficiency of the micropump device 10 is also increased.

  Therefore, the gas generation efficiency and responsiveness when the same amount of the photoresponsive gas generating resin composition is used can be improved, and as a result, miniaturization of the micropump device 10 can be promoted, and the microfluidic device 1 as a whole can be miniaturized. It is possible to proceed.

  In the said embodiment, the photoresponsive gas generation member 13 had the form by which the photoresponsive gas generation resin composition was adhered to the support member surface. However, in the second invention of the present application, the photoresponsive gas generating member does not necessarily have a form in which the photoresponsive gas generating resin composition is attached to the support member. That is, in the micropump device 10 of the above embodiment, instead of the photoresponsive gas generating member 13, only the photoresponsive gas generating resin composition material is accommodated in the gas generating chamber 11 as in the conventional micropump device. May be. When the other structure is the same as that of the above embodiment, a micropump device as an embodiment of the second invention of the present application is configured. In this case, as in the above embodiment, the reflecting member 17 is disposed on the side opposite to the optical window 12 of the photoresponsive gas generating member, so that the light is effectively utilized due to the presence of the reflecting member 17. Thereby, the liquid feeding efficiency of the micropump device is increased.

  As an explanation of the embodiment of the second invention of the present application, the explanation of the configuration other than the support member in the description of the micropump device 10 of the above embodiment is cited. In addition, the description of the modified micropump device 20 and the description of the microfluidic device 1 performed with reference to FIG. 2 below are also incorporated in the description of the micropump device as the embodiment of the second invention. To do. That is, the embodiment of the second invention can also be modified in the same manner as the following modified examples, and can be applied to the following microfluidic device 1.

  FIG. 2 is a schematic partial cutaway front sectional view for explaining a modification of the micropump device 10 of the above embodiment. In the micropump device 20 of this modification, the photoresponsive gas generating member 21 is in multipoint contact with the optical window 12. That is, in the present modification, the photoresponsive gas generating member 21 has irregularities on the optical window 12 side, and has a shape in which a large number of peaks are connected as in the above embodiment. The vertices of the numerous peaks contact the inner surface of the optical window 12 and are in multipoint contact. Therefore, the photoresponsive gas generating member 21 is in multiple contact with the inner surface of the optical window 12. In this case, since the space where the gas is released, that is, the air layer, is formed in the valleys between the plurality of mountains, the generated gas can be quickly released. In addition, the numerous peaks of the photoresponsive gas generating member 21 are in point contact with the inner surface of the optical window 12, so that vibration or external force is applied when the microfluidic device 1 is carried around. However, since the photoresponsive gas generating member 21 is difficult to move in the gas generating chamber 11, an air layer between the mountain portions can be reliably ensured. In addition, since the photoresponsive gas generating member 21 is difficult to move in the gas generating chamber 11, deformation due to the movement of the photoresponsive gas generating member 21 is less likely to occur. Therefore, in the micropump device 20, the reliability is also improved.

  As described above, the microfluidic device 1 according to the present invention has the microchannels 8 and 9 through which the microfluid is conveyed inside the substrate 2, and the microchannel 9 is indicated by a broken line in FIG. The measurement cell 18 shown is connected. In the measurement cell 18, the microfluid sent from the fine flow path 9 is measured using an optical detection method, an electrochemical detection method, or the like. As such a measurement cell, a measurement cell suitable for an appropriate method for detecting a sample in a measurement cell by other methods is formed in addition to a cell for storing a liquid sample for optical measurement. obtain.

  Further, in the microfluidic device 1, in addition to the measurement cell, a dilution unit for diluting the specimen and a mixing unit for mixing are provided as appropriate. Such a configuration can be appropriately modified according to a known structure of a conventionally known microfluidic device.

  Next, the effects of the micropump device of the present invention will be clarified by giving specific examples and comparative examples.

Example 1
100 parts of a 1: 1 mixture of THF and ethanol as a solvent, 64 parts of a methyl methacrylate-acrylamide copolymer (85:15) as a binder resin, and 2.2′-azobis [N- (2 -Propenyl) -2-methylpropionamide] 17 parts, 2,2′-azobis (N-cyclohexyl-2-methylpropionamide) 17 parts, and photosensitivity containing 2,4-dimethylthioxanthone 2 parts as a sensitizer A reactive gas generating resin composition was prepared, soaked in Ben cotton having a thickness of about 1 mm, dried in the dark, and punched out into a circle having a diameter of 8 mm with a punch to produce a photoresponsive gas generating member.

  A gas generation chamber having a circular planar shape and a diameter of 8 mm and a depth of 2 mm was formed as a gas generation chamber shown in FIG. 1A in a substrate made of acrylic resin having a thickness of 3 mm. A photoresponsive gas generating support member was housed in the gas generating chamber, and an optical window was formed with a transparent acrylic adhesive tape. In the gas generation chamber, a reflective member made of aluminum foil was disposed as the reflective member.

In the micropump device configured as described above, a power ultraviolet LED (peak wavelength 365 nm, output 100 mW, directivity 100 °) is used as a light source, and the measured value on the irradiated surface is 20 mW / cm ^{2 and} the irradiation energy is 100 seconds. Irradiated. As a result, the amount of liquid fed for 100 seconds was 34 μL. The amount of liquid fed per second is 346 nL / s on average, and this can advance a droplet of about 35 mm per second in a fine channel having a cross section of 100 μm × 100 μm. This result is sufficient performance for a micropump used in a microfluidic device.

  In addition, about the micropump apparatus of Example 1, irradiation energy was variously changed by carrying out pulse control of the said power ultraviolet LED, and the change of the flow volume was measured. The results are shown in FIG. As can be seen from FIG. 3, in the micropump device of Example 1, the output flow rate shows good linearity with respect to the irradiation energy. Therefore, it is understood that the flow rate can be finely controlled by controlling the irradiation energy.

Further, in the micropump device of Example 1, the time for irradiating the ultraviolet ray with the energy of 20 mW / cm ² was changed to obtain the change in the flow rate of the micropump device. The results are shown in FIG. The horizontal axis in FIG. 4 indicates the irradiation time, and the vertical axis indicates the volume flow rate (μL). From FIG. 4, it can be seen that the volume flow rate increases significantly as the irradiation time increases.

( Reference example )
A micropump device was produced in the same manner as in Example 1 except that the reflecting member made of aluminum foil was omitted. As in Example 1, a power ultraviolet LED was used as the light source, and 20 mW / cm ^2. The irradiation time was variously changed with the irradiation energy of and the change in the volume flow rate of the micropump device of the reference example was obtained. The results are shown in FIG. As can be seen from FIG. 4, the volume flow rate increases as the irradiation time increases.

(Comparative Example 1)
Except for omitting the aluminum foil and Ben cotton, the photoresponsive gas generating resin composition was applied in a gas generating chamber so that the thickness after drying was about 50 μm and dried in a dark place. In the same manner as in Example 1, a micropump device was configured in the substrate. Similarly to Example 1, a power ultraviolet LED was used as a light source, and the irradiation time was changed variously with an irradiation energy of 20 mW / cm ^2. The change in flow rate was determined. The results are shown in FIG. As can be seen from FIG. 4, in Comparative Example 1, the volumetric flow rate is lower than in Example 1 and the reference example , regardless of the irradiation time. It can also be seen that the increase rate of the volume flow rate is very small even if the irradiation time is extended.

DESCRIPTION OF SYMBOLS 1 ... Microfluidic device 2 ... Board | substrate 3 ... Base plate 4-6 ... Intermediate | middle plate 4a ... Through-hole 6a ... Through-hole 7 ... Top plate 8, 9 ... Fine flow path 10 ... Micro pump apparatus 11 ... Gas generation chamber 12 ... Optical window DESCRIPTION OF SYMBOLS 13 ... Photoresponsive gas generating member 14 ... Flow path 17 ... Reflecting member 17a ... Through-hole 18 ... Measurement cell 20 ... Micropump apparatus 21 ... Photoresponsive gas generating member

Claims (7)

A micropump device used in a microfluidic device in which a microchannel is formed in a substrate,
A gas generation chamber is formed in the substrate;
An optical window provided on one surface of the substrate so that the gas generation chamber faces;
Is accommodated in the gas generating chamber, a support member, and a attached to the support member photoresponsive gas-generating resin composition, photoresponse light through said optical window to generate a gas when irradiated A gas generating member,
The support member of the photoresponsive gas generating member is formed of a porous member or a nonwoven fabric;
In the gas generation chamber, the photoresponsive gas generation member is disposed on a surface opposite to the optical window, and includes a reflection member that reflects light emitted from the optical window. , Micro pump device.   The micropump device according to claim 1, wherein the reflecting member is made of a metal foil.   The micropump device according to claim 1, wherein an air layer is formed between the photoresponsive gas generating member and an inner surface of the optical window in the gas generating chamber.   The micropump device according to any one of claims 1 to 3, wherein the photoresponsive gas generating member and the optical window are in point contact at a number of points in the gas generating chamber.   The micropump device according to any one of claims 1 to 4, wherein the photoresponsive gas generating resin composition includes a thermoplastic resin and a gas generating agent that generates a gas when irradiated with light.   The micropump device according to claim 5, wherein the gas generating agent is an azo compound or an azide compound. A measurement channel connected to the microchannel, and a gas generation chamber for generating a gas for driving the microfluid in the microchannel, having a microchannel in which the microfluid is transported. A provided substrate;
A microfluidic device comprising the micropump device according to any one of claims 1 to 6, which is configured using a gas generation chamber of the substrate.

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