JP2003062797A - Micro flow path structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micro flow path structure in which the strength and chemical resistance of the flow path structure are improved, an electro-chemical phenomenon in the fluid of liquid or gas is made inducibly to occur by conducting wiring on the wall of the flow path, the measurement accuracy of electric field, magnetic field and temperature or the like and fluid heating accuracy is improved and a chemical reaction such as catalytic reaction or the like can be accelerated. SOLUTION: The micro flow path structure has a micro flow path for charging or moving fluid therein. The inside wall of the micro flow path has a layered structure comprising at least one material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro flow channel structure suitable for performing chemical and physical operations such as fluid feeding, chemical reaction, analysis, separation, extraction and detection in a micro flow channel.

[0002]

2. Description of the Related Art Recently, a microchannel structure having a microchannel having a length of several cm and a width and depth of sub-μm to hundreds of μm on a glass substrate of several cm square is used. Attention has been paid to so-called integrated chemistry laboratories, which perform chemical and physical operations such as fluid feeding, chemical reaction, analysis, separation, extraction, and detection in a microchannel. Such an integrated chemistry laboratory
Efficient chemical reaction can be performed due to the effect of short molecular diffusion distance in minute space and large specific interfacial area.
Capable of consistently performing reactions, separations, extractions, and detections, accelerating various research and development, labor saving, resource saving, energy saving, space saving, further reduction of experimental waste liquid and waste, repeated experiments There are merits such as rationalization. Figure 1
Shows an example of a micro channel structure having one inlet and two outlets, and FIG. 2 shows an example of a micro channel structure having two inlets and two outlets. .

Such a microchannel structure can shorten the diffusion distance of molecules due to a narrow space in a Y-shaped microchannel having two input ports and one output port, for example. Further, when an interface formed by introducing two different liquids is generated, the reaction efficiency and reaction time can be shortened by easily increasing the specific boundary area. Furthermore, various chemical reactions / separations can be integrated by combining the microchannel structures having such characteristics or increasing / decreasing the number of input / output ports.

As an example showing these, "Microma
chining of Capillary Elec
trophoresis Injecters and
Separators on Glass Chip
s and Evaluation of Flow
at Capillary Intersection
s "(Anal. Chem. pp. 177-184,
(1994) discloses a flow path formed by subjecting a borosilicate glass substrate to groove processing and then heating and welding a borosilicate glass substrate as a cover body as a method for forming a minute flow path. However, in this method, since the inner wall of the flow path in contact with the liquid reagent is determined by the concavo-convex substrate material and the cover body, the liquid transfer reagent is basically due to the chemical resistance or adhesiveness of the glass which is the flow path structure forming material. Is limited. Further, in the minute channel structure formed of resin, there is a problem that the upper limit of the liquid sending pressure is limited by the thickness and adhesive strength of the cover body.

Further, conventionally, the flow channel cross-sectional structure of the above-mentioned fine flow channel structure is constituted by a substrate on which a flow channel pattern is formed, a cover body material for hermetically sealing the substrate, and an adhesive substance depending on a sealing method, No consideration was given to the structural durability and chemical resistance of the flow channel.

Further, when a conductive material or a semiconductor material is wired to make a sensor, a heating element and the like complex and functional, wiring is processed by etching or the like on the surface of the cover body or in the vicinity of the flow path on the uneven substrate. However, in this method, there is a problem in that data accuracy and temperature controllability are problematic because the method moves away from the inside of the flow path for sensing or heating.

In addition, in order to give a minute flow channel structure formed of a glass material or resin a function of electrical, chemical, magnetic and physical, metal, oxide, It is necessary to pattern semiconductors, polymers, etc. Specifically, there are, for example, a heater, a cooling function, a temperature sensor, a magnetic field applying element, an electric field applying element, a piezoelectric element, a discharge tube, and the like. Although some of these functions require direct wiring inside the wall of the flow channel, it has not been realized at present.

[0008]

SUMMARY OF THE INVENTION The object of the present invention was proposed in view of the above conventional circumstances, and a thin film layer structure is formed in a cylindrical shape on a wall surface of a flow path for flowing a fluid such as a liquid or a gas. This improves the flow channel structure strength and chemical resistance, induces electrochemical phenomena in the fluid of liquid and gas by wiring to the wall of the flow channel, measurement accuracy of electric field, magnetic field, temperature, etc. and fluid heating. Another object of the present invention is to provide a fine channel structure capable of improving accuracy and promoting a chemical reaction such as a catalytic reaction.

[0009]

In order to solve the above-mentioned problems, the present inventors have formed minute flow paths on the surface of a substrate,
In a microchannel structure in which a structure is formed by superimposing a cover body having or not having a through hole on this substrate, the inner wall surface of the microchannel has a layered structure made of one or more materials. The problems of the minute channel structure according to the above-mentioned conventional technique can be solved, and the present invention can be finally completed.

The present invention will be described in detail below.

The present invention has a minute flow path for filling or moving a fluid such as gas or liquid therein, and
The micro channel structure has an inner wall surface of the micro channel having a layered structure made of one or more kinds of materials.

Here, the material of the microchannel structure of the present invention itself may be appropriately selected according to its purpose.
Examples thereof include inorganic materials such as soda glass and quartz glass, and polymeric substances such as resins. Further, as a method of forming a minute flow path on the substrate, a shape according to the purpose may be appropriately formed by the method described in the examples.

The microchannel structure of the present invention is formed by laminating and adhering the above-mentioned microchannel substrate and the cover body, and laminating and integrating them. Also, one or more kinds of materials different from or the same as the cover body material are formed in layers.

As a method of forming the layer, a method of previously forming before laminating and then laminating and adhering to each other, a polymer material such as PC (polycarbonate) which is a layer-formed substance after laminating, A metal such as Ni, Cr or Au, a metal such as an alloy, or a metal compound such as a metal oxide may be introduced. More specifically, it can be formed by sequentially forming desired thin films by introducing a UV curable resin, a thermosetting resin, an organometallic complex, and an electroless plating solution. Of these, the metals and the metal compound can be formed in the presence of both. When a UV curable resin, a thermosetting resin, or an organometallic complex is used,
It is possible to selectively form a layered structure at any position in the longitudinal direction of the flow channel.

When the microchannel structure of the present invention is provided with an inlet for introducing a fluid and an outlet for discharging the fluid, it has a cover body having a through hole and a microchannel. The above-mentioned substrate may be superposed on each other and bonded to each other so that they are laminated and integrated.

Further, the microchannel structure of the present invention is not limited to a structure in which the microchannel having an opening such as an inlet and an outlet communicates with the outside, and the microchannel is hermetically sealed inside the structure. Structures that are included are also included. In the microchannel structure having such a sealed structure, a filler according to the purpose is introduced from the fluid inlet of the microchannel structure having the open structure, and then the opening of the microchannel structure is opened. Further, a UV curable resin, a thermosetting resin, etc. are introduced, and they are heat-sealed or cured to be sealed.

FIG. 3 shows cross-sectional views of various flow channel structures as an example of the minute flow channel structure described above. In Figure 3,
In (a) to (c), the cover body 2 is laminated and bonded to the substrate 8 on which the inner wall layer 7 of the minute channel is coated with the above-mentioned predetermined material in a layered manner to form the channel inner wall layer 7. Is.

Further, FIG. 3 (d) shows, for example, that the cover body 2 is laminated and adhered to the substrate 8 on which a predetermined material is applied on both sides in the flow direction of the minute channel to form a thin film. It is a combination.

As described above, in the minute channel structure of the present invention, a thin film can be selectively formed in a part of the channel that joins the plurality of input port channels, so that the inside of the wall surface is directly electrode-formed. It is also possible to realize a light emitting function by introducing not only a liquid but also a gas into the flow path, for example, introducing a luminescent substance and causing discharge.

As a specific example of the forming method, as shown in FIG. 4, when the electroless plating solution 21 and the pure water 22 are introduced into the minute flow path having the minute protrusions 23, the minute protrusions 23 are formed. As a boundary, a laminar flow is generated by the three liquids of the electroless plating liquid 21 and pure water 22, and these liquids do not mix with each other. Due to the generation of the laminar flow, electroless plated metal thin films are formed only on both sides of the flow path with each projection as a boundary. Electroless copper plating inlet 2 for microchannel structure with metal thin film formed
4, two electroless copper plating outlets 26 and pure water outlets 2
7 is sealed, and the pure water inlet 25 is evacuated by a vacuum pump. After that, a small amount of luminescent gas such as neon, argon, carbon dioxide gas, or an additive such as mercury necessary for light emission is introduced, and the pure water inlet 25 is sealed. Then, a so-called neon tube can be formed by using the copper-plated portion (the flow passage inner wall layer 7 in FIG. 3D) as a discharge electrode.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to these examples.

Example 1 As shown in FIG. 5, a microchannel resin molded body was formed to a thickness of 8 mm.
mm diameter 200mm Cr 20n on soda glass substrate
m and Au 100 nm were formed by the DC sputtering method, and then 8 μm 8900D resist manufactured by Tokyo Ohka Co., Ltd. was applied by the spin coating method to prepare a glass master. A photomask on which a linear pattern having a width of 50 μm and a length of 50 mm shown in FIG. 6 was formed was placed on the glass master plate, batch exposure was performed by a UV exposure device, and development processing was performed for patterning processing.

Next, the portion where the gold thin film surface is exposed by patterning is etched with a mixed solution of iodine / ammonium iodide to expose the Cr surface. The Cr thin film is cerium nitrate diammonium cerium Ce (NH ₄ ) ₂ (N
The glass surface was exposed by etching with an O ₃ ) ₆ solution. The glass master was dipped in a 50% hydrofluoric acid aqueous solution for 10 minutes to form a channel having a width of 250 μm and a depth of 100 μm as shown in FIG.
D, Au, and Cr were removed to prepare a glass master plate in which only the glass surface was exposed. A Ni thin film having a thickness of 800 nm was formed on the glass master by DC sputtering, and then immersed in a Ni sulfamate electroforming solution to prepare a 300 μm Ni stamper by an electroforming method. P using an injection molding method using the Ni stamper
A C resin molded body was prepared.

On the patterned resin-molded substrate,
A PC resin cover body having a thickness of 100 μm and having a through hole with a diameter of 0.5 mm formed in advance at a predetermined position was pressure-welded in a 145 ° C. atmosphere. An inlet / outlet port of the resin molded body having a hollow structure and a capillary tube were connected by an adapter via an O-ring, and a UV-curing resin SD-318 manufactured by Mitsubishi Rayon was injected by a syringe pump. After confirming that SD-318 spreads throughout the microchannel, nitrogen gas was filled instead of SD-318 in the syringe to purge the microchannel with nitrogen. With the interior of the channel purged with nitrogen, UV light was exposed for 10 minutes to photo-cure SD-318 adhering to the channel wall surface. FIG. 8 shows an enlarged view of the channel cross-sectional structure.

A flow rate of ethyl acetate of 10 was applied to the created microchannel.
Continuous liquid feeding was carried out for 1 hour at 0 μl / min and a liquid feeding pressure of 1 MPa, but no chemical change in the minute channel and damage to the cover layer occurred.

Comparative Example 1 A 100 μm-thick PC resin cover body having a 0.5 mm diameter through hole formed in a predetermined position in advance on the patterned resin-molded substrate prepared in Example 1 was placed under an atmosphere of 145 ° C. Was pressure welded. When ethyl acetate was fed at a flow rate of 50 μl / min in a state where the channel wall surface coating with the UV curable resin was not performed on this minute channel molded body, the minute channels instantly became cloudy and finally heat-welded. The sheet melted and liquid leakage occurred. In addition, pure water flow rate 1
When the liquid was sent at 00 μl / min and the sending pressure was 1 MPa, the cover in the flow path portion was peeled off.

Example 2 A 100 μm thick PC resin cover body having through holes of 0.5 mm diameter formed in advance at predetermined positions was formed on the patterned resin-molded substrate prepared in Example 1 under an atmosphere of 145 ° C. -It was left standing for 2 hours and 45 minutes under pressure to be welded. A flow rate of Au electroless plating solution was applied to the microchannel structure 1
After sending the solution at 00 μl / min for 5 minutes, the substrate cross section was broken, and the cross section was observed by SEM (secondary electron microscope). As a result, it was confirmed that an Au thin film was formed on the wall surface of the channel. Ethyl acetate flow rate 100μ to this microchannel molding
The solution was fed at 1 / min, but no chemical change appeared in the microchannel.

Example 3 An injection-molded body substrate prepared in Example 1 and a P layer having a thickness of 100 μm in which a through hole having a diameter of 0.5 mm was previously formed at a predetermined position.
Mitsubishi Rayon S on both sides of the C resin cover
D-318 UV curable resin was applied by spin coating. After the coated surfaces were stuck together, they were exposed to a UV lamp for 10 minutes to be cured. Ethyl acetate was fed to the microchannel molded body at a flow rate of 100 μl / min, but no chemical change appeared in the microchannel.

Example 4 After the Au electroless plating solution was fed to the microchannel structure prepared in Example 1 at a flow rate of 100 μl / min for 5 minutes,
As a result of rupturing the cross section of the substrate and observing the cross section with an SEM (secondary electron microscope), it was confirmed that a multilayer structure of the SD-318 / Au thin film was formed in a cylindrical shape on the wall surface of the flow channel. A flow rate of 100 μl of ethyl acetate solution in the microchannel /
Although the solution was sent at a min, no chemical change appeared in the microchannel.

Example 5 A film forming mask as shown in FIG. 9 was set on the patterned resin-molded substrate prepared in Example 1. Using this method, a SiO ₂ thin film was formed to a thickness of 200 nm within a width of 0.5 mm from the flow path by the RF sputtering method. Similarly, the same mask is placed on the cover body, and the SiO ₂ thin film
It was formed to 0 nm. The resin-molded substrate prepared by the above method and the SiO ₂ thin film pattern of the cover body were sandwiched so as to coincide with each other, and left standing for 2 hours and 45 minutes in a pressurized state at 145 ° C. to perform welding. An ethyl acetate solution was fed into the microchannel at a flow rate of 100 μl / min, but no chemical change occurred in the microchannel.

Example 6 A film forming mask as shown in FIG. 9 was placed on the patterned resin-molded substrate prepared in Example 1. Using this method, a NiCr thin film was formed in a width of 0.5 mm from the flow path portion to a thickness of 500 nm by the DC sputtering method. Similarly, the same mask is placed on the cover body, and the NiCr thin film
It was formed to 0 nm. The resin-molded substrate prepared by the above method and the NiCr thin film pattern of the cover body were sandwiched so as to coincide with each other, and left standing for 2 hours and 45 minutes in a pressured state at 145 ° C. for welding. Wiring was applied on the NiCr thin film exposed at the input / output port of the flow channel, and voltage was applied to confirm that pure water reached 80 ° C.

Example 7 A pattern having a convex portion at the bottom of the flow channel as shown in FIG. 10 was formed on a resin molded substrate, and the width of the input / output flow channel was 100 μm, the depth was 100 μm, the length was 15 mm, and the width was 300 μm. 1
A confluent channel having a length of 00 μm and a length of 40 mm was obtained. A Cu thin film layer was formed on both sides of the central channel by simultaneously sending Cu electroless liquid to both sides of the three channels at 100 μl / min and pure water to the central channel at 100 μl / min for 5 minutes. Formation was confirmed. In FIG. 10 of the present microchannel structure, 1,
Make electrical wiring so that voltage can be applied to the 3rd port,
A sodium hydroxide aqueous solution was sent at 100 μl / min to apply a voltage. Generation of a mixed gas of hydrogen and oxygen was confirmed at ports 1 ', 2', and 3 '.

[0033]

The microchannel structure of the present invention has a substrate material and a cover body on the whole or part of the surface of the inner wall surface of the microchannel obtained by bonding the substrate on which the microchannel is formed and the cover body. At least one type of material that is different from or the same as the material is formed into a layered structure, which prevents corrosion of the flow channel wall surface by a fluid such as a liquid or gas gas, improves the flow channel strength by liquid pressure / gas pressure, and further catalyses. It is possible to promote a chemical reaction such as a reaction. In addition, when a structure in which a microfluid is sealed inside a structure is adopted, it can be applied to so-called neon tubes and the like, which is industrially useful.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a microchannel structure.

FIG. 2 is a diagram showing a microstructure having two inlets and two outlets.

FIG. 3 is a diagram showing various sectional structures of a minute channel.

FIG. 4 is an explanatory diagram for forming the minute channel of FIG. 3 (d).

FIG. 5 is a diagram showing a method for producing a micro channel structure.

FIG. 6 is a diagram showing a mask used for collective exposure.

FIG. 7 is a diagram showing a minute channel structure.

FIG. 8 is a diagram showing a cross-sectional structure of a minute channel.

FIG. 9 is a diagram showing a sputter mask used during film formation.

FIG. 10 is a diagram showing a minute channel structure in Example 7.

[Explanation of symbols]

1: Micro flow path 2: Cover body 3: Microchannel substrate 4: Inlet 5: outlet 6: Through hole 7: Channel inner wall layer 8: Substrate 9: Soda glass 10: Photoresist 11: Metal thin film layer Cr / Au 12: Photomask for surface 13: Ni 14: Surface stamper 15: Mold 16: Resin 17: Substrate on which uneven pattern is formed 18: Cover body (made of PC resin) 19: PC resin 20: UV curable resin layer 21: Electroless copper plating solution 22: Pure water 23: Small protrusion 24: Electroless copper plating solution inlet 25: Pure water inlet 26: Electroless copper plating solution discharge port 27: Pure water outlet

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G01N 31/20 G01N 31/20 // G01N 37/00 101 37/00 101 (72) Inventor Keiichiro Nishizawa 2F042 HA02 HA10 4F100 AA17B AB01B AB16 AG00 AK01B AK45 AS00B AT00A BA02 BA07 DA11 EC03 EH66 EJ17 GB90 JB02 EE03 FA10 BB23EE01 FA12 BB23EE10 FA03BB01EE01 FA02 BB23EE05 FABBBBBEEEE FB12

Claims (7)

[Claims] 1. A micro-channel for filling or moving a fluid therein, and an inner wall surface of the micro-channel has a layered structure made of one or more kinds of materials. Micro channel structure. 2. The minute channel structure according to claim 1, wherein the minute channel structure is formed by stacking a substrate having minute channels and a cover body. 3. The microchannel structure according to claim 2, wherein the layered structure is formed on all or part of the surfaces of the substrate and the cover body having the microchannel. 4. The microchannel structure according to claim 1, wherein all or part of the layer structure is made of a polymer material. 5. The microchannel structure according to claim 1, wherein all or part of the layer structure is formed of one or more kinds of metals and / or metal compounds. body. 6. An inlet for introducing a fluid and an outlet for discharging the fluid are provided.
6. The microchannel structure according to any one of 5 to 5. 7. The fine channel structure according to claim 1, wherein the end of the fine channel is sealed.