WO2003008961A1

WO2003008961A1 - Micro-channel sold crossing structural body, and method for forming sold crossing multi-layer flow

Info

Publication number: WO2003008961A1
Application number: PCT/JP2002/004428
Authority: WO
Inventors: Takehiko Kitamori; Akihide Hibara; Manabu Tokeshi; Kenji Uchiyama
Original assignee: Kanagawa Academy Of Science And Technology
Priority date: 2001-07-11
Filing date: 2002-05-07
Publication date: 2003-01-30
Also published as: JP2003028836A

Abstract

A structural body in which substrates having micro-channels are layered, with micro-channel arrangement surfaces facing to each other. The micro-channels arranged on each substrate cross each other in a three-dimensional manner at least in a part thereof, and a liquid-liquid interface of liquid flowing through the micro-channels is formed at the solid crossing parts.

Description

Specification

Method of forming microchannel multilevel crossover structure and multilevel multilevel flow

The invention of this application relates to a method for forming a microchannel three-dimensional crossover structure and a three-dimensional crossover multilayer liquid. More specifically, the invention of the present application is based on a three-dimensional flow channel that is useful for precision microanalysis, precision separation, or fine chemical synthesis in microchips and the like having a microchannel (microchannel). The present invention relates to a micro-channel structure crossed over a substrate and a method for forming a three-dimensionally cross-linked liquid using the same. Background art

Attention has been focused on methods of precisely performing microanalysis, separation, or chemical synthesis using fine channels formed in glass substrates and the like. For example, as one of the chemical operations using a micro-channel as such a fine channel, various separation methods utilizing the characteristics of a micro-channel micro space have been proposed, such as electrophoresis and chromatography. Discussions are underway on such matters.

However, in the case of many conventional methods, there is a problem that it is practically applicable only to an aqueous solution system, and it is difficult to apply the method to continuous operation or multi-stage operation that requires complicated integration.

Under these circumstances, the inventors of the present application proposed a new liquid-liquid method for solvent extraction and chemical synthesis in order to solve the problem that conventional versatility is poor and high-level integration is difficult. We have developed methods for forming layer liquids and gas-liquid interfaces.

However, in the studies conducted by the inventors so far, since the microchannels are formed on the same substrate surface, there are restrictions on the integration of the microchannels configured in the microchip. Since the liquid-liquid interface is also formed mainly by the interfacial tension, problems such as the stability of the interface and the difficulty of phase separation remain. In view of the above, the invention of this application can greatly improve the degree of integration of the flow channel in the microchip, facilitate continuous operation and multi-stage operation, and have a stable interface and good phase. It is an object of the present invention to provide a new technical means for high integration and formation of a multilayer flow, which can easily realize the separability. Disclosure of the invention

The invention of this application solves the above-mentioned problems. First, a structure in which a substrate on which microchannels are provided is stacked with the microchannel mounting surfaces facing each other, At least a part of the microchannels disposed on the substrate is vertically intersected with each other, and a liquid-liquid interface of the liquid flowing through the microchannel is formed at the three-dimensional intersection. The present invention provides a microchannel three-dimensional intersection structure.

In addition, the second aspect of the present invention is characterized in that one surface of the upper and lower microphone opening channels constituting the three-dimensional intersection is made hydrophobic and the other surface is made hydrophilic. Thirdly, in the above-mentioned microchannel three-dimensional crossover structure in which the aqueous phase and the oily phase are circulated, the pressure difference at the liquid-liquid interface between the aqueous phase and the oily phase is 60%. The present invention provides a microphone-channel stereoscopic crossing structure characterized by being 0 Pa or less. Fourth, the microchannels of the upper substrate to be crossed are stacked via the upper substrate upper surface or the intermediate substrate. The microchannel crossover structure, which is characterized by communicating with the microchannels provided on the lower or upper surface of the upper substrate by through holes, fifthly, the micro opening of each substrate The microchannel three-dimensional intersection structure is provided with a liquid supply part and a drainage part communicating with the channel. Sixth, the invention of this application is directed to a sixth aspect of the present invention, in which the liquid is circulated through the microphone opening channels of each of the upper and lower substrates by using any of the above-described three-dimensional channel intersection structures, and the liquid-liquid interface is formed at the three-dimensional intersection. Provided is a method for forming a three-dimensionally cross-layered liquid, which is characterized by forming a multi-layered flow. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic view illustrating the outline of the structure of the present invention. FIG. 2 is a schematic view different from FIG.

FIG. 3 is a cross-sectional view of a main part illustrating a three-dimensional intersection.

FIG. 4 is a cross-sectional view of a principal part showing another example different from FIG.

FIG. 5 is a graph illustrating a flow velocity difference and a pressure difference between a nitrogen channel and water flowing through the microchannel of the structure of the present invention.

Fig. 6 is a conceptual diagram showing the arrangement when there are a plurality of microchannel intersections.

FIG. 7 is a process step diagram illustrating the formation of the microchannel of the structure of the present invention.

FIG. 8 is a plan view illustrating the arrangement of the three-dimensional intersection of microchannels.

FIG. 9 is an exploded perspective view illustrating the structure of the present invention in the embodiment.

FIG. 10 is a micrograph illustrating the liquid-liquid interface at the intersection.

FIG. 11 is a photograph illustrating the state of the liquid-liquid interface when the ODS process is performed and when it is not performed.

In addition, the code | symbol in a figure shows the following.

1 A Lower board

1 A 1 Micro Channel

1 B Upper board

1 B 1, 1 B 2 microchannel

1 B 3 Through hole

2 intersection

3 Liquid-liquid interface

4 BEST MODE FOR CARRYING OUT THE INVENTION The invention of this application has the features as described above, and embodiments thereof will be described below.

First of all, what is characteristic of the invention of this application is the three-dimensional integration of flow channels using microchannels and the formation of a liquid-liquid interface with a three-dimensional intersection.

FIG. 1 and FIG. 2 schematically illustrate this, for example, as illustrated in FIG. 1, in the structure of the invention of this application. The microchannel (1A1 ) Is formed on the lower substrate (1A) and the lower substrate on which the microchannel (1B1) is formed is the microchannel (1A1) (1B1). ) Are laminated with their forming surfaces facing each other. At the intersection (2), the liquid flowing through each of the upper and lower microchannels A A) (1B1) intersects three-dimensionally to form a liquid-liquid interface (3). I am trying to.

The example of FIG. 2 also shows an intersection (2) where such a liquid-liquid interface is formed, but is longer than the intersection (2) of the example of FIG. 1 in the flow direction of the liquid-liquid interface. (L) is longer. This length (L) means the contact length as a multilayer flow, as also shown in FIG.

Of course, the length (L) of the intersection (2) and the location and number of the intersection (2) can be determined as appropriate according to the operation purpose and application of the structure of the present invention.

In the invention of this application, the microchannel (1 B 1) formed on the lower surface of the upper substrate (1 B) forming the liquid-liquid interface (3) by the above-mentioned three-dimensional intersection (2) For example, as shown in FIG. 4 exemplifying a partial cross section, the microchannel (1B2) formed on the upper surface of the upper substrate (1B) and the through-hole (1B3) can communicate with each other. On top of the microchannel (1B2), another substrate or cover plate (4) may be laminated. For example, with this configuration, the degree of freedom in selecting the position of the intersection (2) of the microchannel (1B1) with respect to the microchannel (1A1) of the lower substrate (1A) is increased. growing. Microphone on top This is because the upper liquid can be guided to a predetermined position by the mouth channel (1B2) and a liquid-liquid interface can be formed at the intersection (2) at the predetermined position.

In such a configuration, by further increasing the number of substrates, it becomes possible to freely configure the flow path circuit three-dimensionally, for example, similarly to a multilayer printed wiring board.

For this reason, it goes without saying that, for example, a substrate as an intermediate layer may be interposed.

In any case, the formation of the liquid-liquid interface due to the three-dimensional crossing between the upper and lower liquids is performed in order to form a stable interface between the upper liquid and the lower liquid, and the properties of each liquid, surface tension, specific gravity, compatibility, etc. Points will be taken into account. Naturally, the flow velocity or the liquid temperature is determined in consideration of these points. The means for supplying the fluid to the flow path and the means for discharging the liquid from the flow path are also appropriately determined.

As a means for forming a stable interface, it is also effective to make one surface of the microchannel above and below the steric intersection hydrophobic and make the other hydrophilic. For example, the surface of a microchannel formed on a glass substrate can be effectively hydrophobized by subjecting it to a silane treatment with trichloride octadecylsilane (0DS) or the like. For example, it is considered that an oil phase (organic phase) is circulated through the surface of the microphone channel whose surface is hydrophobized, and an aqueous phase is circulated through the other microchannel having a hydrophilic surface so that the microchannel crosses up and down.

At this time, the liquid-liquid interface of both the oil phase and the aqueous phase is stably formed when the range of the pressure difference at the liquid-liquid interface of the oil phase and the aqueous phase is 600 Pa or less. This pressure difference can be derived from the flow rate difference between the oil phase and the aqueous phase. For example, Fig. 5 (a) shows the measured flow rates of both liquids when nitrobenzene was used as the oil phase and water was used as the aqueous phase. In the figure, the upper and lower limits of the flow rate of water for forming a stable liquid-liquid interface when the flow rate of nitrobenzene as the oil phase is 0 to 6 tI / min are shown.

Using the values of these flow rates, the value of pressure loss at the liquid-liquid interface of benzene and water was determined. Note that in this calculation, The pressure of water and the pressure of nitrobenzene were assumed to be the same (atmospheric pressure). The pressure loss ΔP of the liquid when the length of the channel is L is expressed as follows: P / L = fp V ² / D. Where f is the coefficient of friction, iO is the density, and V is the average velocity of the liquid. D corresponds to the average hydraulic diameter,

D = 4 S / 1 Note that S is the cross-sectional area of the microchannel, and 1 indicates the perimeter of the cross-section of the microphone channel. The microphone mouth channel used in the experiment has D of 135 m.

Also, the Reynolds number (R e) is

R e = / 0 V D / At, the Re of the liquid in the microchannel of the invention of this application is 0 to 1.966, and this flow can be regarded as laminar flow. In the case of laminar flow, f is given by f = 16 / Re. With the above relationship, the flow velocity difference between the oil phase and the aqueous phase can be converted to a pressure difference.

Figure 5 (b) shows the upper and lower limits of the pressure difference at the liquid-liquid interface of nitrobenzene and water to form a stable liquid-liquid interface.

In the above calculations, the density of water was 0.998 g / mL, the density of benzene was 1.204 g / mL, and the viscosity of water was 1.002 mP. The viscosity of a's and nitrobenzene was set at 1.863 mPa · s.

When the flow rate of benzene is 0 l Zmin, it is allowed. Although the range of the pressure difference is small, the allowable range of the pressure difference is exceptional because the hydraulic characteristics of the stopped liquid are completely different from the hydraulic characteristics of the fluid.

In addition, in order to confirm whether or not it is possible to form a plurality of three-dimensional intersections as shown in Fig. 6, the pressure difference in the counterflow was estimated. In this estimation, the flow rate of nitrobenzene was 3 AtI / min and the flow rate of water was 6 nI / min. In FIG. 6, there are four three-dimensional intersections, and the three-dimensional intersections are provided at 5 mm intervals. Under these conditions, the pressure drop gradient △ P_L of nitrobenzene is 7900 Pa / m, and the ΔPZL of water is 850 Pa / m The pressure of benzene and the pressure of water between the parts are 39.5 Pa and 42.5 Pa. Between these four crossovers, the pressures of nitrobenzene and water are 18.5 Pa and 12.7 Pa.

In order to realize the counterflow, the range of the pressure difference needs to be 250 Pa or less. Since this value is within the range of the allowable pressure difference of the microchannel, the invention of this application can be applied to the case where there are a plurality of three-dimensional intersections.

As for the microchannel itself, as in the conventional case, it is considered that the width is about 50 Oim or less and the depth is about 20 Otm or less, but is not limited to this. In addition, the flow velocity of the fluid is generally considered to be about 20 μ. I Zmin or less, but is not limited thereto.

The microchannel of the three-dimensional intersection structure of the present invention can be formed by various processing methods such as, for example, lithography and jet etching.

For example, FIG. 7 illustrates an example of this method for a glass substrate as a process step including a 0DS hydrophobizing treatment of a lower substrate. In this example, after depositing Cr (chromium) and Au (gold) on the surface of a glass substrate, a microchannel is formed by photolithography and one-to-one etching, and a lower channel (1A) is formed on the lower substrate (1A). DS (silane) treatment for hydrophobic surface You. It goes without saying that the ODS (silane) treatment may be performed after the resist and metal stripping.

The lamination of the lower substrate (1A) and the upper substrate (1B) for forming the three-dimensional intersection (2) may be performed by heat fusion, or by screwing or crimping with a holder. .

For example, the three-dimensional formation of the liquid-liquid interface by the microchannel standing crossover structure of the present invention as described above can be performed by separation by solvent extraction or the like, analysis by a reagent reaction, analysis by optical means, Is useful for chemical synthesis methods, etc., and also as a channel formation itself by three-dimensional three-dimensional crossing. Depending on its purpose and application, a plurality of three-dimensional intersections may be arranged in the flow path. For example, as illustrated in FIG. 8, various forms such as crossing the microchannel (1A1) of the lower substrate and the microchannel (1B1) of the upper substrate are possible.

Therefore, an example will be described below, and the embodiment will be further described ₍ Example

Two Pyrex glasses were used for the microchip substrate (upper plate ■ lower plate). According to the process shown in Fig. 7, micro channels crossing between the substrates were processed on both substrates by photolithography-feed etching. Only the lower plate was modified with trichlorooctadecylsilane to make the microchannel surface of the lower plate hydrophobic (lipophilic). In order to protect the chemical modification, the substrates were not heat-sealed, and as shown in Fig. 9, the substrates were bonded only by screwing and pressure from the holder. The flow of the two phases of oil-water used was shown. FIG. 10 is an enlarged photograph of a portion where two microchannels processed on the upper and lower surfaces are in contact while intersecting with each other. Benzene benzene is circulated in the oil phase, and fluorescent fine particles are dispersed in the aqueous phase as a probe. The black streamline in Fig. 10 indicates the streamline on the water phase side. It can be seen that each phase contacts and forms a stable interface that crosses three-dimensionally, flows linearly according to the hydrophilicity (hydrophobicity) of the surface, and then completely separates. A stable interface can be easily formed by chemical modification, and integration such as multi-step operation after phase separation can be easily realized.

In addition, a comparison was made between the microchannels that had been modified with triclonal octadecylsilane and those that had not been modified. Fig.

Shown in 1 1. Figure 11 (a) shows the result of modifying the microchannel with triclonal octadecylsilane, and Figure 11 (b) shows the result without modification.

As is clear from FIG. 11, the surface of the microchannel can be effectively hydrophobized by performing a silane treatment with trichloride octadecylsilane (ODS) or the like.

Industrial applicability

As described in detail above, the invention of this application can greatly improve the degree of integration of channels in microchannels, facilitate continuous operation and multistage operation, and realize stable interfaces and good phase separation. A new technical means for high integration and formation of a multi-layer liquid can be provided.

Claims

The scope of the claims

1. A structure in which the substrates on which the microchannels are arranged are stacked with the microchannel arrangement surfaces facing each other, and the microchannels arranged on each substrate are at least partially connected to each other. A micro-channel three-dimensional intersection structure, wherein a liquid-liquid interface of a liquid flowing in the micro-channel is formed at the three-dimensional intersection.

2. The microchannel three-dimensional intersection structure according to claim 1, wherein one surface of the upper and lower microchannels constituting the three-dimensional intersection is made hydrophobic, and the other surface is made hydrophilic.

3. The microchannel according to claim 2, wherein the aqueous phase and the oily phase are circulated, wherein the pressure difference at the liquid-liquid interface between the aqueous phase and the oily phase is 600 Pa or less in the three-dimensional cross structure. Standing cross structure.

4. The microchannels of the upper substrate intersecting the S body are connected to the microchannels disposed on the lower surface or the upper surface of the upper substrate laminated via the upper substrate or the intermediate substrate through through holes. 4. The microchannel three-dimensional intersection structure according to claim 1, wherein:

5. The microphone-port channel crossover structure according to any one of claims 1 to 4, wherein a liquid supply unit and a drainage unit communicating with the microchannel of each substrate are provided.

6. With the microchannel three-dimensional intersection structure according to any one of claims 1 to 5, a liquid is allowed to flow through the microchannels of the upper and lower substrates to form a multilayer liquid in which a liquid-liquid interface is formed at the three-dimensional intersection. A method for forming a three-dimensionally intersected multilayer liquid.