JP2004073995A - Method for controlling flow rate, micro fluid device, and apparatus for controlling flow rate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow rate controlling method which can easily and accurately control the flow rate of a fluid in a minute channel. <P>SOLUTION: In the method, the flow rate of a fluid flowing in capillary channels 4 and 6 is controlled by using a magnetic fluid which can be introduced into the channels 4 and 6. By adjusting the position of the magnetic fluid in relation to the channels 4 and 6 by a magnetic field acting on the magnetic fluid, the flow rate of the fluid in the channels 4 and 6 can be controlled. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a method for controlling the flow rate of a controlled fluid flowing through a capillary channel, a microfluidic device capable of controlling the flow rate of a controlled fluid by the flow rate control method, and controlling the flow rate of a controlled fluid in the microfluidic device. Device.
[0002]
The present invention relates to, for example, a microchemical device, that is, a microdevice for a chemical or biochemical reaction (microreactor) in which a microchannel is formed; a membrane filtration device, a dialysis device, a deaeration / aspiration device, an extraction device, and the like. Chemical and physicochemical treatment devices; DNA analysis devices, immunoanalysis devices, electrophoresis devices, chromatography, gas analysis devices, water quality analysis devices, and other microanalysis devices. INDUSTRIAL APPLICABILITY The present invention can be used for a nozzle for manufacturing a microarray such as a DNA chip and an apparatus incorporating the nozzle.
[0003]
[Prior art]
As a method of controlling the flow rate of a fluid flowing through a capillary channel formed in a microfluidic device, a method of controlling the flow rate by adjusting the inner diameter of the capillary channel by pressure from the outside has been disclosed in Japanese Patent Application Laid-Open No. H11-163873. 2001-70784 and JP-A-2000-288504.
However, in this method, since a part of the microfluidic device is deformed by applying an external force, unless the microfluidic device has a thick and rigid structure, the entire microfluidic device bends when an external force is applied, and other valve mechanism parts And when a window for optical detection is provided, there is a problem that the position is shifted. In addition, it is necessary to form a microfluidic device using a material having a mechanical property that does not break down while exhibiting a sufficient deformation amount and recovers to almost the original shape, and there is a problem that the selection of the material is restricted. Was. Furthermore, when a microfluidic device having a small external size is used, there is a problem that an extremely high-precision holding mechanism or a compression mechanism is required to hold the microfluidic device and press a required portion. Was.
[0004]
As a method of controlling the fluid flow rate in the flow path of the microfluidic device, there is a method in which a flow control valve is provided in the microfluidic device and this valve is used. In this case, pipes and wiring for driving the valve are connected. Therefore, there is a problem that the structure of the microfluidic device is complicated.
In addition, it is necessary to increase the strength of the device in order to connect the pipes and the wirings, so that it is difficult to reduce the size of the device. For this reason, there was a problem that many parallel processing became difficult.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a flow rate control method capable of easily and accurately controlling the flow rate of a controlled fluid in a minute flow path.
[0006]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve the above problems, and as a result, using a magnetic fluid that can be introduced into a capillary channel, adjusting the position of the magnetic fluid with respect to the channel, It has been found that it is possible to control the flow rate of the controlled fluid by adjusting the ease of flow of the controlled fluid in the above, and the present invention has been completed based on this finding.
[0007]
That is, the present invention is a method of controlling the flow rate of the controlled fluid flowing through the capillary channel using a magnetic fluid that can be introduced into the channel, and the position of the magnetic fluid with respect to the capillary channel, There is provided a flow rate control method characterized in that the flow rate of a controlled fluid in the flow path is controlled by adjusting the magnetic field acting on the magnetic fluid.
The flow rate control method of the present invention controls the flow rate of the controlled fluid in the flow path by adjusting the position of the magnetic fluid with respect to the flow path by using a magnetic field. And highly accurate flow control can be realized.
Further, compared to the conventional flow control method, since a complicated mechanism such as a valve and a pipe for driving the valve is not required, the present invention can be applied to a microfluidic device having a small size or a microfluidic device having a low strength. .
[0008]
The present invention has a capillary flow path through which a controlled fluid flows, and a magnetic fluid can be introduced into the flow path, and the controlled flow in the flow path depends on the position of the magnetic fluid with respect to the flow path. Provided is a microfluidic device, which is configured to control a flow rate of a fluid.
Since the microfluidic device of the present invention can control the flow rate of the controlled fluid in the flow path according to the position of the magnetic fluid with respect to the flow path, even if the flow path is minute, In addition, easy and accurate flow control can be realized.
Therefore, the size of the device can be reduced. Further, since it is not necessary to increase the strength, the structure of the device can be simplified, and the manufacturing cost can be reduced.
[0009]
The present invention is an apparatus for controlling a flow rate of a controlled fluid in a microfluidic device having a capillary flow path through which a controlled fluid flows, and in which a magnetic fluid can be introduced into the flow path, the microfluidic device Holding means, a magnetic field generating means for generating a magnetic field acting on the magnetic fluid of the microfluidic device held by the holding means, and adjusting the magnetic field to adjust the position of the magnetic fluid with respect to the capillary channel. A flow control device, characterized in that the flow control device has an adjustable magnetic field adjusting means.
ADVANTAGE OF THE INVENTION The flow control apparatus of this invention can adjust the position of the magnetic fluid in a microfluidic device accurately by simple operation.
Therefore, in a microfluidic device having a minute flow path, easy and highly accurate flow rate control can be realized.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
The flow rate control method of the present invention can introduce a flow rate of a controlled fluid flowing through a capillary channel (hereinafter, the “capillary channel” may be simply referred to as a “channel”) into the channel. In this method, the flow rate of the fluid to be controlled in the flow path is controlled by adjusting the position of the magnetic fluid with respect to the flow path by a magnetic field acting on the magnetic fluid.
[0011]
In the flow control method of the present invention, the ease of flow of the controlled fluid in the flow path is adjusted by adjusting the position of the magnetic fluid with respect to the flow path.
For example, by arranging the magnetic fluid at a position that does not hinder the flow of the controlled fluid, the flow rate of the controlled fluid can be relatively increased.
By arranging the magnetic fluid at a position where the flow path of the portion where the controlled fluid flows is narrowed, the flow of the controlled fluid is made difficult and the flow rate of the controlled fluid can be relatively reduced.
By disposing the magnetic fluid at a position where the flow path is completely closed, the flow of the controlled fluid can be stopped.
As described above, the flow rate of the controlled fluid is controlled by adjusting the ease of the flow of the controlled fluid in the flow path using the magnetic fluid.
[0012]
In the present invention, the outer shape of the flow path is arbitrary, and may be, for example, a tubular capillary.
The flow path may also be formed inside the bulk molded article, and may be a capillary flow path formed in a so-called microfluidic device.
In the present invention, the channel refers to a cavity for moving a fluid therein or therethrough, and in addition to a mere transfer channel, a reaction channel, a detection channel, an extraction or other processing channel, a valve or the like. It may be a cavity of a pump section or the like.
[0013]
The cross-sectional shape of the flow channel is arbitrary, and may be rectangular (including rounded rectangles), trapezoidal, circular, semi-circular, slit-like, and other complex shapes.
As for the cross-sectional dimension of the flow channel, the width and the height are each preferably 3 μm to 3 mm, more preferably 10 μm to 1 mm.
The cross-sectional area of the channel is preferably 5 × 10 ^-12 m ² ~ 5 × 10 ^-6 m ² , More preferably 1 × 10 ^-10 m ² ~ 1 × 10 ^-6 m ² And most preferably 1 × 10 ^-10 m ² ~ 1 × 10 ^-7 m ² It is.
[0014]
If the cross-sectional dimension or cross-sectional area is less than the above range, it becomes difficult to control the flow rate. If the cross-sectional dimension or cross-sectional area exceeds the above range, the control becomes difficult or impossible.
The above-described cross-sectional shape, cross-sectional dimension, and cross-sectional area are for the portion into which the magnetic fluid is introduced, and other portions, for example, the portion through which the controlled fluid flows, are arbitrary, but the magnetic fluid is introduced. It is preferably the same as the portion.
[0015]
The method of the present invention may also use a magnetic fluid storage connected to the flow path. For example, a microfluidic device in which a magnetic fluid storage unit is formed can be used.
When the magnetic fluid storage unit is used, the flow rate of the controlled fluid in the flow channel can be controlled by adjusting the amount of the magnetic fluid introduced from the magnetic fluid storage unit to the flow channel by the magnetic field. .
For example, if the entire amount of the magnetic fluid is stored in the magnetic fluid storage unit, the flow rate of the controlled fluid can be relatively increased because the magnetic fluid does not obstruct the flow of the controlled fluid in the flow path at all.
In addition, by introducing an amount of magnetic fluid from the magnetic fluid storage section into the flow path, which narrows the flow path of the flow path of the controlled fluid, the flow of the controlled fluid is reduced, and the flow rate of the controlled fluid is relatively small. can do.
Further, the flow of the controlled fluid can be stopped by introducing an amount of the magnetic fluid that completely closes the flow path from the magnetic fluid storage unit to the flow path.
[0016]
The magnetic fluid storage unit may be, for example, a tank in which a part of the flow path is widened, a capillary cavity branched from a part of the flow path, or the like.
The capillary cavity branched from a part of the flow path may have a closed end, may have a cavity of any shape connected to the end, or may be open to the outside of the device. May be.
[0017]
In the present invention, it is preferable to use a magnetic fluid storage unit. This magnetic fluid storage portion is preferably a capillary cavity branched from a part of the flow path, and the capillary cavity preferably has a cavity of any shape connected to its end. .
[0018]
In the method of the present invention, the flow rate of the controlled fluid in the flow path may be controlled without using the magnetic fluid storage unit (for example, using a microfluidic device having no magnetic fluid storage unit). it can.
In this case, the flow rate of the controlled fluid in the flow path can be controlled by introducing the magnetic fluid into the flow path and adjusting the position of the magnetic fluid in the flow path by the magnetic field. .
For example, if the magnetic fluid in the flow path is arranged at a position that does not obstruct the flow of the controlled fluid as much as possible (for example, a position close to the inner wall surface of the flow path), the flow rate of the controlled fluid can be relatively increased.
In addition, if the magnetic fluid in the flow path is arranged at a position where the flow path in the portion where the controlled fluid flows is narrowed, the flow of the controlled fluid is made difficult, and the flow rate of the controlled fluid can be relatively reduced.
Further, if the magnetic fluid in the flow path is arranged so as to completely close the flow path, the flow of the controlled fluid can be stopped.
[0019]
The method of the present invention is preferably directed to a fluid flowing through a microfluidic device in which a flow channel is formed.
A microfluidic device, also called a microfluidic device, a microfabricated device, a lab-on-a-chip, or a micro total analytical system (μ-TAS), allows a fluid to flow in In the path to the outflow, a mechanism in which the fluid undergoes temperature changes, a mechanism in which the concentration is adjusted, a mechanism in which a fluid undergoes a chemical reaction, a mechanism in which flow is controlled, such as flow velocity, flow branching, mixing or separation, or electrical, A device having a capillary channel provided with a mechanism for receiving an optical measurement or the like.In the present invention, a magnetic fluid can be introduced into the channel, and depending on the position of the magnetic fluid with respect to the channel, A structure that can control the flow rate of the controlled fluid in the flow path can be used.
[0020]
In the method of the present invention, the controlled fluid of interest is arbitrary and can be a liquid, a gas, a supercritical fluid. Of course, the controlled fluid may be a solution or a dispersion fluid (a fluid in which a dispersoid is dispersed in a dispersion medium).
[0021]
The magnetic fluid used in the present invention is a liquid material exhibiting ferromagnetism. Preferred specific examples include powders of ferromagnetic solids such as metals and alloys such as iron, cobalt and nickel; and metal oxides such as iron oxide. A liquid material stably dispersed in a liquid can be given.
The ferromagnetic solid and the dispersion medium are arbitrary, and can be selected according to the material of the microfluidic device in which the flow path is formed and the fluid to be controlled.
For example, a ferromagnetic solid having a particle size that does not block the flow path can be selected and used.
As the dispersion medium, one that is incompatible with the controlled fluid or one that does not affect the microfluidic device can be selected and used.
[0022]
A suitable value can be selected for the viscosity of the magnetic fluid according to the ease of movement in the flow channel. For example, the viscosity of the magnetic fluid can be selected according to the time from when the magnetic field is changed to when the magnetic fluid is displaced to a desired position.
It is preferable to use a magnetic fluid having a viscosity of 100 to 10000 mPa / s.
When the cross-sectional area of the flow path is small, a low-viscosity one is preferable, and when the cross-sectional area of the flow path is large, a high-viscosity one is preferable.
[0023]
In the present invention, the position of the magnetic fluid is adjusted by appropriately adjusting the magnetic field acting on the magnetic fluid.
The magnetic field generating means for generating a magnetic field is not particularly limited, but for example, a magnet such as a permanent magnet or an electromagnet can be used. For the purpose of adjusting the flow rate of the controlled fluid, it is preferable to use a permanent magnet. This is because the permanent magnet makes it easy to finely adjust the position of the magnetic fluid and consumes less energy.
On the other hand, when the purpose is to open and close the flow path with a magnetic fluid, an electromagnet is simple and preferable. However, when an electromagnet is used, it is preferable to use a magnetic field generating means including a permanent magnet and an electromagnet that generates a magnetic field stronger than the permanent magnet.
When the electromagnet is stopped (in a state where no magnetic field is generated), the magnetic fluid can be arranged in the first stable position by the permanent magnet, and when the electromagnet is activated (in a state where a magnetic field is generated). It is preferable that the magnetic fluid be arranged at the second stable position.
[0024]
To adjust the magnetic field, the direction and / or strength of the magnetic field may be adjusted.
For example, a method of changing the distance between the magnetic fluid and the magnet in the flow path; a method of moving the magnet along the flow path while keeping the distance to the magnetic fluid substantially constant (conversely, the flow path may be changed to a magnet A method of providing a magnetic line shielding structure or a magnetic line short path structure between a magnet and a magnetic fluid, and moving the magnetic line shielding structure or the magnetic line short path structure; and a method of changing a current supplied to an electromagnet. A method of continuously or discretely adjusting the direction and / or intensity of the magnetic field by changing the current supply position of the electromagnet.
Among them, a method of adjusting a magnetic field by moving a permanent magnet is the easiest method, and is therefore preferable.
Adjusting the magnetic field acting on the magnetic fluid includes the case where the magnetic field before or after the adjustment is zero.
[0025]
When reducing the flow rate of the controlled fluid or stopping the flow of the controlled fluid, the magnetic fluid is controlled by applying a strong magnetic field to control the flow rate against the pressure of the controlled fluid. It is preferable to fix in position.
On the other hand, in order to increase the flow rate of the controlled fluid, when disposing the magnetic fluid at a position that does not hinder the flow, it is preferable to fix the magnetic fluid at that position by the action of a magnetic field.
That is, in order to adjust the position of the magnetic fluid, it is preferable to always apply a magnetic field to the magnetic fluid, and change the operation position to position the magnetic fluid.
When placing the magnetic fluid in a position that does not impede the flow of the controlled fluid, do not apply a magnetic field to the magnetic fluid and use gravity or capillary action to prevent the magnetic fluid from moving from a predetermined position. You can also.
[0026]
To adjust the direction and / or strength of the magnetic field, a plurality of magnets may be used for one magnetic fluid. Further, a group of a plurality of magnetic fluids may be used to close one flow path. The number of flow paths whose flow rates can be controlled using the magnetic fluid is arbitrary, and the flow rates of the controlled fluids in the plurality of flow paths can be independently controlled.
[0027]
In the present invention, a flow path through which the controlled fluid flows is provided, and the magnetic fluid can be introduced into the flow path, and the flow rate of the controlled fluid in the flow path is controlled according to the position of the magnetic fluid with respect to the flow path. A microfluidic device adapted to do so is provided.
The constituent material of the microfluidic device of the present invention is arbitrary. For example, glass, crystal material (crystal, etc.), metal material (stainless steel, etc.), semiconductor material (silicon), ceramic, carbon, organic polymer polydimethylsiloxane, etc. As described above, a material containing an inorganic element may be used.
In the present invention, the position of the microfluidic device is adjusted by applying a magnetic field to the magnetic fluid in the microfluidic device. It is preferably formed of a magnetic material or a ferromagnetic material having a relative permeability of 1,000 or less, and more preferably a paramagnetic material or a diamagnetic material.
The shape of the microfluidic device of the present invention is arbitrary, and can be formed according to the application and purpose. For example, it may be in the form of a lump, a plate, a sheet (including a film, a ribbon, and a belt), a fiber (a hollow fiber), or the like, or a composite structure thereof, for example, a part of a flow channel is a hollow fiber. And a structure in which the portion where the flow path into which the magnetic fluid is introduced is formed is plate-like.
When the microfluidic device is a microchemical device, it is preferably in the shape of a plate or a sheet.
[0028]
The flow path formed in the microfluidic device of the present invention is formed by a member having a concave portion and a cover adhered to the surface thereof, or formed by a defective portion of a layer sandwiched between at least two members. It is preferable that
The microfluidic device of the present invention preferably has a configuration in which a magnetic fluid is loaded inside. As the magnetic fluid used in the microfluidic device of the present invention, the same fluid as that described in the above flow rate control method can be used.
In the microfluidic device of the present invention, the flow path in the device does not have to be branched.
[0029]
The flow rate control device of the present invention is a device for controlling a flow rate of a controlled fluid in a microfluidic device having a flow path through which a controlled fluid flows, and in which a magnetic fluid can be introduced into the flow path. ) Holding means for holding the microfluidic device, (2) magnetic field generating means for generating a magnetic field acting on the magnetic fluid of the microfluidic device held by the holding means, and (3) adjustment of the magnetic fluid to the flow path by adjusting the magnetic field. Magnetic field adjusting means whose position can be adjusted.
[0030]
The holding means is arbitrary as long as it holds the microfluidic device so that the magnetic fluid in the microfluidic device can be moved to a predetermined position by the magnetic field generated by the magnetic field generating means (magnet).
Preferably, the holding means is capable of determining the position of the microfluidic device with respect to the magnetic field generating means (magnet) with good reproducibility.
The holding means may fix the microfluidic device at a specific position in the holding means, or may adjust the position of the microfluidic device.
The holding means preferably includes a fixing mechanism for fixing the device and a positioning mechanism for adjusting the position of the device, and is preferably configured to be able to hold the microfluidic element by one operation.
[0031]
As the magnetic field generating means, any means can be used as long as it can apply a magnetic field to the magnetic fluid, and a magnet such as a permanent magnet or an electromagnet can be used. In particular, the use of a permanent magnet is preferred.
The type, shape, size, position, and the like of the magnet are arbitrary as long as the position of the magnetic fluid in the microfluidic device can be adjusted by the magnetic field generated thereby. The area of the portion of the magnet facing the microfluidic device is 1 × 10 ^-11 m ² ~ 1 × 10 ^-3 m ² And preferably 1 × 10 ^-6 m ² ~ 1 × 10 ^-4 m ² Is more preferable.
The magnetic field generating means referred to in the present invention means a means capable of moving a magnetic fluid in a flow path in a microfluidic device. For example, a magnetic field generating means such as a permanent magnet or an electromagnet for a motor is used. However, it does not include those that cannot move the magnetic fluid in the microfluidic device by the magnetic field.
One or more magnets may be used as the magnetic field generating means. When there are a plurality of magnets, the plurality of magnets may adjust (fix or move) different magnetic fluids respectively, or may adjust (fix or move) one magnetic fluid. There may be.
Two magnets can be placed on the front and back sides of the microfluidic device, and the two magnets can position (fix or move) one magnetic fluid in the microfluidic device.
[0032]
Preferably, the magnetic field adjusting means is capable of adjusting the direction and / or strength of the magnetic field.
For example, a moving mechanism of a magnet; a moving mechanism of a microfluidic device; a mechanism for changing a shielding state of a magnetic field line between the magnet and the microfluidic device; a driving mechanism of a short path mechanism of a magnetic field line between the magnet and the microfluidic device. possible.
When the magnet is an electromagnet, a mechanism for selectively supplying a current to a predetermined one of the plurality of electromagnets; a mechanism for changing a current supplied to a predetermined one of the plurality of electromagnets may be used.
Among these, a mechanism for moving a permanent magnet; a mechanism for selectively supplying a current to a predetermined one of a plurality of electromagnets; and a mechanism for changing a current supplied to a predetermined one of a plurality of electromagnets are particularly preferable.
A mechanism for selectively supplying a current to a predetermined one of the plurality of electromagnets, or a mechanism for changing the current to be supplied to a predetermined one of the plurality of electromagnets is separated from the electromagnets and holding means and housed in a housing. May be used.
[0033]
The magnetic field adjusting means may be capable of adjusting the magnetic field by sequence control or feedback control by computer control or the like.
[0034]
The flow control device of the present invention has other mechanisms, for example, a temperature control mechanism, an optical or other detection mechanism, a sample injection mechanism, a valve mechanism, a cleaning mechanism, etc., according to the intended use of the microfluidic device. May be.
[0035]
The flow control device of the present invention includes, for example, a reaction device such as a microreactor and a PCR (PCR; polymerase chain reaction) device; a membrane filtration device, a dialysis device, an electrodialysis device, a gas separation device, a gas dissolution device, Pretreatment device for chemical analysis such as extraction device; Chemical or biochemical analyzer such as gene analyzer, immunoanalyzer, gas analyzer, water quality analyzer, etc .; Suitable for spotter for microarray production such as DNA chip and immune chip Can be used.
[0036]
FIG. 5 shows an example of the flow control device of the present invention.
The flow control device shown here comprises a holding means 21 for holding the microfluidic device 20, a permanent magnet 22 (magnetic field generating means) for generating a magnetic field acting on the magnetic fluid in the device 20, and a magnetic fluid for adjusting the magnetic field. Magnetic field adjusting means 23 for adjusting the position.
The holding means 21 includes a fixing mechanism 25 for fixing the device 20 and a positioning mechanism 26 for adjusting the height position of the device 20.
The fixing mechanism 25 includes a mounting table 27 on which the device 20 is mounted, and a pressing mechanism 28 which is a spring for pressing the device 20 against the mounting table 27.
The positioning mechanism 26 can move the fixing mechanism 25 up and down.
[0037]
The magnetic field adjusting means 23 includes an elevating mechanism 29 for elevating and lowering the permanent magnet 22, a first moving mechanism 30 for moving the permanent magnet 22 in the left-right direction in FIG. 5B, and a permanent magnet 22 shown in FIG. And a second moving mechanism 31 that moves the paper toward the near side and the far side in FIG.
The magnetic field adjusting means 23 adjusts the direction and / or intensity of the magnetic field acting on the magnetic fluid in the device 20 by arranging the permanent magnet 22 at a predetermined position by the elevating mechanism 29 and the moving mechanisms 30 and 31. The position of the magnetic fluid can be adjusted.
[0038]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the scope of the following examples. In the following examples and comparative examples, “parts” is “parts by weight”.
[0039]
[Energy beam irradiation device]
A light source unit for a multi-light 250 type exposure apparatus manufactured by Ushio Inc. incorporating a 250 W ultra-high pressure mercury lamp was used. UV intensity 50 mW / cm unless otherwise noted ² It is.
[0040]
[Viscosity measurement method]
The measurement was performed at room temperature (24 ± 2 ° C.) using a VM-100A vibrating viscometer manufactured by Yamaichi Electric Co., Ltd.
[0041]
[Production Example 1]
[Preparation of energy ray-curable composition (i)]
As the active energy ray crosslinkable polymerizable compound, 60 parts of a trifunctional urethane acrylate oligomer having an average molecular weight of about 2000 (“Unidick V-4263” manufactured by Dainippon Ink and Chemicals, Inc.), and 1,6-hexanediol diacrylate 20 parts of "New Frontier HDDA" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., and nonylphenoxy polyethylene glycol (n = 17) acrylate ("N-177E" manufactured by Daiichi Kogyo Seiyaku Co., Ltd.); 20 parts) and 5 parts of 1-hydroxycyclohexyl phenyl ketone (“Irgacure 184” manufactured by Ciba Geigy) as a photopolymerization initiator were uniformly mixed to prepare a composition (i).
[0042]
[Preparation of energy ray-curable composition (ii)]
As the active energy ray crosslinkable polymerizable compound, 60 parts of a trifunctional urethane acrylate oligomer having an average molecular weight of about 2000 (“Unidick V-4263” manufactured by Dainippon Ink and Chemicals, Inc.), and 1,6-hexanediol diacrylate 20 parts of "New Frontier HDDA" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., and nonylphenoxy polyethylene glycol (n = 17) acrylate ("N-177E" manufactured by Daiichi Kogyo Seiyaku Co., Ltd.); 20 parts), 5 parts of 1-hydroxycyclohexylphenyl ketone (“Irgacure 184” manufactured by Ciba Geigy) as a photopolymerization initiator, and 2,4-diphenyl-4-methyl-1-pentene (2) as a polymerization retarder 0.5 part of Wako Pure Chemical Industries, Ltd.) was uniformly mixed to prepare composition (ii).
[0043]
[Production of microfluidic device]
As the base material 1, a plate material made of polyacrylate ("Acrylite L 000" manufactured by Mitsubishi Rayon Co., Ltd.) was used, and the composition (i) was applied thereto using a bar coater (127 μm in thickness), and 50 mW / cm. ² The composition (i) was semi-cured by irradiating the ultraviolet ray for 3 seconds in a nitrogen atmosphere to obtain a coating film 2 (resin layer 2).
[0044]
The composition (ii) was applied on the semi-cured coating film 2 using a bar coater (127 μm in thickness), and the flow paths 4 and 6 shown in FIG. 50 mW / cm is applied to portions other than the portion serving as the magnetic fluid storage portion 5. ² Is irradiated in a nitrogen atmosphere for 3 seconds to partially cure the irradiated portion of the composition (ii), and then the uncured portion of the uncured composition (ii) is washed and removed with ethanol. The coating film 3 (resin layer 3) on which the groove-shaped resin deficient portions (width 200 μm, depth 140 μm) to be the flow paths 4 and 6 and the storage portion 5 were formed was formed, and the member A was obtained.
[0045]
As a temporary support (not shown), a 5 cm × 5 cm × 30 μm polypropylene film (“biaxially stretched polypropylene film“ Taiko ”FOR No. 30” manufactured by Nimura Chemical Industry Co., Ltd.) was used, and a bar was placed on the film. The composition (i) was applied using a coater to form a coating film 7 (resin layer 7) (thickness: 127 μm), 50 mW / cm. ² Was irradiated for 3 seconds in a nitrogen atmosphere without a photomask, and the coating film 7 was semi-cured to obtain a member B.
Next, the coating film 7 in a semi-cured state is brought into close contact with the coating film 3 of the member A, and the coating film 7 and the temporary support are adhered on the coating film 3 by irradiating ultraviolet rays for another 30 seconds. The defective portions of the coating film 3 were defined as capillary channels 4 and 6 and a storage portion 5 (channel 5).
The flow paths 4 and 6 are formed in directions perpendicular to each other, and are connected to each other at a branch portion 13. The storage part 5 is formed in a direction parallel to the flow path 6, and is connected to the flow paths 4 and 6 at the branch part 13.
[0046]
[Formation of connection port]
The support is peeled off from the coating film 7 of the member B after bonding, and the composition (i) is applied on the exposed coating film 7 to form a coating film 8 (resin layer 8). A 5 cm × 5 cm × 1 mm plate 9 made of the same polyacrylate (“Acrylite L No. 000” manufactured by Mitsubishi Rayon Co., Ltd.) is overlapped with the above-mentioned base material 1 and 50 mW / cm. ² Was irradiated in a nitrogen atmosphere without a photomask for 40 seconds, thereby laminating a member C composed of an acrylate plate material 9 and a coating film 8 on the coating film 7.
Next, a controlled fluid inlet 10 and a controlled fluid outlet 12 are respectively applied to the coating films 7, 8, 9 at positions corresponding to the ends of the flow paths 4, 6 and the storage unit 5 by using a drill having a diameter of 3 mm. The magnetic fluid inlets 11 were formed, and a polyvinyl chloride tube having an inner diameter of 3 mm and a height of 5 mm was adhered to these to obtain a microfluidic device 14.
[0047]
[Example 1]
About 5 μl (5 × 10 5) from the magnetic fluid inlet 11 of the microfluidic device 14 obtained in Production Example 1 ^-9 m ³ ) Was introduced into the flow path 5 (manufactured by Ritile Management Co., Ltd., viscosity: 400 mPa · s).
As shown in FIG. 1B, a permanent magnet 15 (alnico magnet) having a diameter of 6 mm and a length of 30 mm, which is fitted with a truncated conical pole piece having a circular tip having a diameter of 3 mm, is brought close to the lower surface of the device 14. Was.
As shown in FIG. 2, by disposing the permanent magnet 15 at a position close to the branch portion 13, the magnetic fluid M was moved until the distal end portion reached the branch portion 13.
20 μl (2 × 10 ^-8 m ³ When the distilled water (colored water) is introduced into the flow channel 4 from the inlet 10 at a pressure of about 1.1 kPa, the colored water flows from the flow channel 4 to the flow channel 6 via the branch 13, and from the outlet 12. Leaked.
[0048]
When the permanent magnet 15 was moved toward the flow path 6 (to the right in the figure), the magnetic fluid M also moved toward the flow path 6 with the movement of the permanent magnet 15.
As shown in FIG. 3, in a state where the front end of the magnetic fluid was close to the flow path 6, the colored water became difficult to flow due to the magnetic fluid M, and the flow rate was reduced.
As shown in FIG. 4, when the permanent magnet 15 was further moved toward the flow path 6, the magnetic fluid M closed the flow path 6, and the flow of the colored water was cut off. At this time, the magnetic fluid M and the coloring water were not mixed.
[0049]
【The invention's effect】
The flow rate control method of the present invention controls the flow rate of the controlled fluid in the flow path by adjusting the position of the magnetic fluid with respect to the flow path by using a magnetic field. And highly accurate flow control can be realized. For this reason, many parallel processing becomes easy.
Further, compared to the conventional flow control method, since a complicated mechanism such as a valve and a pipe for driving the valve is not required, the present invention can be applied to a microfluidic device having a small size or a microfluidic device having a low strength. .
[0050]
The microfluidic device of the present invention has a flow path through which a controlled fluid flows, and a magnetic fluid can be introduced into the flow path, and the controlled fluid in the flow path depends on the position of the magnetic fluid with respect to the flow path. Can be controlled, so that easy and highly accurate flow control can be realized even when the flow path is minute.
Therefore, the size of the device can be reduced. Further, since it is not necessary to increase the strength, the structure of the device can be simplified, and the manufacturing cost can be reduced.
[0051]
Since the flow rate control device of the present invention includes holding means for holding the microfluidic device, magnetic field generating means for generating a magnetic field acting on the magnetic fluid, and magnetic field adjusting means for adjusting the position of the magnetic fluid by adjusting the magnetic field. The position of the magnetic fluid in the microfluidic device can be accurately adjusted by a simple operation.
Therefore, in a microfluidic device having a minute flow path, easy and highly accurate flow rate control can be realized.
[Brief description of the drawings]
FIG. 1 shows an example of the microfluidic device of the present invention, wherein (a) is a plan view and (b) is a side view.
FIG. 2 is an explanatory diagram illustrating a method for controlling a flow rate in the microfluidic device shown in FIG.
FIG. 3 is an explanatory diagram illustrating a method for controlling a flow rate in the microfluidic device shown in FIG.
FIG. 4 is an explanatory view illustrating a method for controlling a flow rate in the microfluidic device shown in FIG. 1;
FIGS. 5A and 5B show an example of the flow control device of the present invention, wherein FIG. 5A is a plan view and FIG. 5B is a side view.
[Explanation of symbols]
4, 6 ... flow path, 5 ... magnetic fluid storage part, 14, 20 ... microfluidic device, 21 ... holding means, 22 ... permanent magnet (magnetic field generating means), 23 ... .Magnetic field adjusting means, M: magnetic fluid

Claims (7)

A method of controlling the flow rate of a controlled fluid flowing through a capillary channel using a magnetic fluid that can be introduced into the channel,
A flow rate control method comprising: controlling a flow rate of a controlled fluid in a flow path by adjusting a position of a magnetic fluid with respect to a capillary flow path by a magnetic field acting on the magnetic fluid. Using a magnetic fluid storage unit connected to the capillary channel, the amount of the magnetic fluid introduced from the magnetic fluid storage unit into the capillary channel is adjusted by the magnetic field, whereby the controlled fluid in the channel is controlled. The flow control method according to claim 1, wherein the flow is controlled. ^2. The flow control method according to claim 1, wherein a cross-sectional area of the capillary channel is 5 × 10 ⁻¹² m ^{2 to} 5 × 10 ⁻⁶ m ² . The flow control method according to claim 1, wherein the capillary channel is formed in a microfluidic device. 2. The flow control method according to claim 1, wherein the magnetic field is provided by a permanent magnet. It has a capillary flow path through which a controlled fluid flows, and a magnetic fluid can be introduced into the flow path, and the flow rate of the controlled fluid in the flow path is adjusted according to the position of the magnetic fluid with respect to the flow path. A microfluidic device configured to be controllable. An apparatus for controlling a flow rate of a controlled fluid in a microfluidic device having a capillary flow path through which a controlled fluid flows and in which a magnetic fluid can be introduced into the flow path, wherein the holding apparatus holds the microfluidic device Means,
Magnetic field generating means for generating a magnetic field acting on the magnetic fluid of the microfluidic device held by the holding means,
A flow rate control device for a microfluidic device, comprising: a magnetic field adjusting means capable of adjusting the position of the magnetic fluid with respect to the capillary channel by adjusting the magnetic field.

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