JP2013061354A - Device and method for fluid control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid control method in which designing cost and initial cost are reduced.SOLUTION: A fluid channel is formed in a micro fluid device, and includes a flow rate control unit for changing a temperature of a liquid flowing in the fluid channel. A temperature control member in which heat sources the number of which is larger than the number of the flow rate control units in the micro fluid device are two-dimensionally arranged on the micro fluid device. The heat sources which are arranged on the flow rate control units among the heat sources are selectively operated so as to control, through the flow rate control units corresponding to the fluid channels, the flow rates of the liquid flowing in the fluid channel.

Description

  The present invention relates to a fluid control method and apparatus, and more particularly to a fluid control method in a flow path through which a fluid passes. For example, it is mainly used for a method for controlling the flow rate and flow rate of a liquid in a microfluidic device of an integrated small analysis system (μTAS) manufactured by a micromachining technique.

  In various industrial processes, techniques for controlling the flow rate and flow rate of gases and liquids are indispensable. Generally, the flow rate or flow rate is adjusted by adjusting the degree of opening of the proportional valve installed in the flow path. If the size of the proportional valve is routine, for example, on the order of millimeters or more, the structure can be satisfactorily satisfied by a mechanical structure that changes the cross-sectional area through which fluid passes.

  However, in the micromachining field, it is very difficult to produce such a proportional valve in the micron order region and the submicron order region. As a method for controlling the fluid in the flow path below the micro order, for example, there are methods disclosed in Non-Patent Documents 1 to 4.

Non-Patent Document 1 discloses a method using a stimulus-responsive gel. This method uses the expansion and contraction of the gel to open and close the valve. Gel expansion and contraction is accomplished by changing volume in response to temperature or pH stimuli.
Non-Patent Document 2 discloses a method using an electrochemical reaction. In this method, bubbles are generated in the flow path by an electrochemical reaction to create a valve function.
Non-Patent Document 3 discloses a method of deforming a flow path. In this method, the flow rate is changed by physically deforming the flow path with air pressure.
Non-Patent Document 4 discloses a method of mechanically installing a pin in a flow path. This method uses a braille display to push a pin into the flow path, physically close the flow path, and change the flow rate.

Further, there are devices disclosed in Patent Literature 1 and Patent Literature 2 as devices for handling a minute fluid. Patent Document 1 discloses a micro total analysis system that stabilizes a mixing ratio of a plurality of fluids. Patent Document 2 discloses a temperature control system for a microfluidic device.
JP 2006-266923 A JP 2008-157932 A Nature, 2000, 404, p. 588-590 Anal. Chem. 2002, vol. 74, p. 6392-6396 Science, 2000, 288, p. 113-116 Proc. Natl. Acad. Sci. USA, 2004, 101, p. 15861-1586

  The method using the stimulus-responsive gel disclosed in Non-Patent Document 1 has a problem that it is limited to a fluid that does not chemically react with the gel. Even if this method can realize 100% open and 100% closed valves, there is a problem in gel expansion / contraction reproducibility and stimulus reproducibility when controlling a certain opening, and stable control is possible. There was a problem that it was difficult.

  The method using the electrochemical reaction disclosed in Non-Patent Document 2 is similar to the method using the stimulus-responsive gel described above, even if a 100% open and 100% closed valve can be realized. When controlling, there existed a problem that stable control was difficult. In addition, it takes time for the generated bubbles to disappear, and there is a problem that the bubbles cannot be eliminated with good reproducibility. There is also a problem that only fluids that respond to electrochemical reactions can be applied.

  The method of deforming the flow path disclosed in Non-Patent Document 3 controls the constant opening even if a 100% open and 100% closed valve can be realized, as in the method using the stimulus-responsive gel. In this case, there is a problem that stable control is difficult. Further, when the flow path is deformed by pressure, there are problems that the flow path is limited to a material that bends due to pressure and that the bending operation for many years causes fatigue inside, resulting in a short life. Also, the material that bends will inherently bend by other factors. For example, the pressure of the fluid itself, environmental temperature fluctuations, and environmental atmospheric pressure fluctuations cause flow control errors.

  The method of mechanically installing the pin in the flow path disclosed in Non-Patent Document 4 is the same as the method using the stimulus-responsive gel, even if a 100% open and 100% closed valve can be realized. In the case of controlling the opening degree, there is a problem that stable control is difficult. Further, there is a problem that the fluid is limited to those that do not chemically react with the pin material. Further, the pin pushing mechanism is a fine mechanical mechanism, and is expensive and complicated, and has a problem of lacking long-term reliability. Furthermore, the sealing performance between the pin extrusion mechanism and the liquid contact portion is poor, and there is a problem of liquid leakage.

  As described above, the method disclosed in Non-Patent Document 1 realizes this using a special material or a special structure. In addition, some of the functions can only realize the function of a valve that can only control on or off to flow or stop the flow rate. Further, the disadvantages of these methods are that the structure is complicated, the failure frequency is high and the reliability of long-term use is not high, and at the same time the production cost is high. Further, when a special material is used, the affinity and durability between the material and the fluid often become a problem, and the target fluid may be limited. Overall, as a structure that can reliably control the desired flow rate and flow rate for many years, it is still unusable.

Patent Document 1 discloses a micro total analysis system. Since the field described in Patent Document 1 is an area where the present invention is most active, I would like to clarify the problems of this conventional technique.
In the micro integrated analysis system of Patent Document 1, when fluids are merged and mixed, the flow path resistance, specifically, the flow path cross-sectional area and the flow path length are changed according to the mixing ratio to produce a test chip. . The necessity and background of stabilizing the mixing ratio are described in paragraphs [0001] to [0004] of Patent Document 1. However, the solution is not an essential solution to the problem. The problem is that the flow rate deviates from the target value, and the cause is described in paragraph [0003] of Patent Document 1. Even in the method described here, the flow rate changes with time due to changes in the micropump capacity with time, changes in physical properties of the fluid, changes in flow channel shape with time, and environmental changes.

  When the sample liquid and the reaction reagent liquid are mixed in the test chip provided with the fine flow path, a location where the liquids are mixed is provided in the fine flow path. The mixing ratio of the sample solution and the reaction reagent solution varies depending on the process. As a method of flowing the liquid into the fine flow path, there are a method of using a micro pump provided in the inspection chip, a method of applying pressure to a predetermined position on the inspection chip, and a suction from a predetermined position of the inspection chip. In any method, the flow rate and flow rate are determined by the pressure and the resistance of the flow path. In the prior art, the mixing ratio between the liquids is designed so that the resistance of the flow path becomes approximately that value. However, the mixing ratio is not necessarily the initial design value due to a flow rate error or flow rate error due to a flow path size error due to an error during transfer formation, a flow path size error due to environmental temperature fluctuation, a change in fluid viscosity, or the like. For this reason, there is a problem that the chemical reaction by mixing the sample solution and the reaction reagent is not always stable, and the test chip is erroneously determined.

  Patent Document 2 discloses a temperature control system for a microfluidic device. Problems of the conventional method when controlling the temperature of the fluid are described in paragraphs [0006] to [0011] of Patent Document 2. The microfluidic device has a size of about several centimeters (centimeters) × several centimeters, and the channel size is 200 μm (micrometers) or less. With such a fine structure, the temperature control of each part is very important, but there is no method that may include the method disclosed in Patent Document 2. In addition, since the fluid flow rate and flow rate control methods disclosed in Non-Patent Documents 1 to 4 and Patent Document 1 are closely related to the temperature control of the flow path, paragraphs [0006] to [0011] of Patent Document 2. The problem described in] occurs.

  Therefore, the present invention provides a fluid control method and apparatus that can realize control of the flow rate of fluid with a simple structure as compared with the prior art, have few failures, are inexpensive, and can be miniaturized. It is intended.

The present invention is a fluid control method in which the viscosity of the fluid is changed by changing the temperature of the fluid flowing in the flow path, and the flow rate of the fluid in the flow path is changed.
The fluid control method according to the present invention is based on the physical phenomenon that the viscosity of the fluid changes according to its temperature. In general, as the temperature increases, the viscosity of the liquid decreases and the viscosity of the gas increases. This is a phenomenon that can be explained by the dynamic behavior of molecules. Conventionally, as a factor that disturbs fluid control due to the change in viscosity due to this temperature change, the structure is such that the fluid temperature is controlled to be constant, or that some change in viscosity does not affect fluid control. It was proposed to do. In contrast, the present invention actively uses this disturbing factor to control the flow rate of the fluid. Here, the present invention can control the flow rate of the fluid as well as the flow rate of the fluid.

A graph showing the relationship between the temperature of water, which is a typical fluid, and the change in viscosity is shown in FIG. In FIG. 18, the horizontal axis represents temperature (° C. (degrees Celsius)), and the vertical axis represents viscosity Pa · s (Pascal second).
At an atmospheric pressure of 0.1 MPa (megapascal), 0 ° C. to 100 ° C. exists as a liquid, so that the flow rate and flow rate of water can be controlled within that temperature range. Water at a constant temperature and a constant pressure flows at a constant flow rate. Here, when the temperature of water is increased, the flow rate is increased, and when the temperature of water is decreased, the flow rate is decreased. This is because water tends to flow due to a decrease in viscosity with increasing temperature. Strictly speaking, the temperature of the narrow tube also changes with the temperature of the fluid, and if the material expands as the temperature rises (general substances follow this), the diameter of the narrow tube increases and the fluid increases. .

  In the fluid control method of the present invention, the means for changing the temperature of the fluid in the flow path can include changing the temperature of the flow path. Specifically, by changing the temperature of the flow path, the temperature of the fluid in the flow path is changed to change the viscosity of the fluid, thereby changing the flow rate of the fluid.

  In the fluid control method of the present invention, the flow path is formed in the microfluidic device, has a flow rate control unit for changing the temperature of the liquid flowing in the flow path, and exists in the microfluidic device. A temperature control member in which more heat sources than the number of flow control units are arranged in a two-dimensional array is provided on the microfluidic device, and the heat sources arranged on the flow control unit among the heat sources are selectively operated. As a result, the flow rate of the liquid flowing in the flow path is controlled via the corresponding flow rate control unit.

  A microfluidic device uses at least two substrates, forms grooves on the surface of one substrate or both substrates, and bonds the two substrates together to bond the two substrates. A flow path is formed on the surface. There is also a microfluidic device in which a base material having a groove penetrating from the front surface to the back surface is sandwiched between two base materials and formed inside. A microfluidic device is disclosed in Patent Document 2, for example.

  Examples of the heat source that changes the temperature of the flow path include a Peltier element, a heater, and a light source for irradiating the flow path with light. An example of the heater is a semiconductor element. However, the heater may have another structure. Moreover, as a light source for irradiating the said flow path with light, LED (Light Emitting Diode) and a semiconductor laser can be mentioned, for example. However, the light source is not limited to these. In addition, a light source and an optical fiber may be used, and light that has entered the incident end of the optical fiber from the light source may be emitted from the emission end of the optical fiber to irradiate the light to the flow path.

  In a preferred embodiment, the temperature control member is one in which the heat sources are arranged along a direction orthogonal to each other in a plane, and holds address data indicating the position of the heat source arranged on the flow rate control unit. The heat source is selectively operated based on the address data.

  In the fluid control method of the present invention, the flow rate of the liquid may be shut off by clogging the flow path by lowering the temperature of the flow path to solidify the liquid. Furthermore, the temperature of the flow path can be returned to the original or increased, and the solidified liquid can be liquefied to open the flow path.

Further, an obstacle may be installed inside the flow path.
The flow path may be installed on a curve.
Further, the flow path may be formed so that the flow path cross-sectional area of the part whose temperature is controlled is smaller than that of the other part.

  In the fluid control method of the present invention, the boundary length where the fluid is switched to a laminar flow state or a turbulent flow state is adjusted by adjusting the pipe length of the flow channel and the flow velocity, density and viscosity of the fluid flowing in the flow channel. An example in which the flow rate of the fluid is changed by changing the viscosity of the fluid by changing the temperature of the flow path or the fluid and changing the fluid from a laminar flow state to a turbulent flow state or vice versa. Can be mentioned.

  Further, a relationship between the set temperature of the flow path or the fluid and the flow rate of the fluid may be acquired in advance, and a desired flow rate may be obtained based on data indicating the relationship.

  Also, a plurality of the flow paths are formed by using a plurality of the flow paths that merge at the downstream junction, and controlling the flow rates of the fluids that flow through the flow paths by controlling the temperatures of the flow paths. The ratio of the fluid supplied to the junction may be controlled.

  The fluid control device of the present invention is provided on a microfluidic device having at least one flow path having a flow rate control unit for changing the temperature of a liquid flowing in the flow path, and on the microfluidic device, A temperature control member in which more heat sources than the number of the flow rate control units existing in the microfluidic device are arranged in a two-dimensional array, and the heat source arranged on the flow rate control unit among the heat sources. By selectively operating, the flow rate of the liquid flowing in the flow path is controlled via the corresponding flow rate control unit.

  The heat source is, for example, a heater, a Peltier element, an LED, or a semiconductor laser.

  In a preferred embodiment, a microcomputer for controlling the flow rate of the liquid flowing in the flow path is provided, and the temperature control member is one in which the heat sources are arranged along a direction orthogonal to each other in a plane. Address data indicating the position of the heat source arranged on the flow rate control unit is held, and the heat source is selectively operated based on the address data.

In one form, the flow path is formed by removing a part of a glass member, a semiconductor member, or a metal member by an etching technique.
In another embodiment, the flow path is formed by transferring a mold formed by a photolithography technique and an etching technique onto a resin.

In the fluid control method and apparatus of the present invention, the temperature control member is a two-dimensional array in which more heat sources than the number of flow rate control units existing in the microfluidic device are arranged. Since the heat source arranged on the unit is selectively operated, the heat source not arranged on the flow rate control unit is wasted, but the design cost and initial cost can be reduced as the total cost. This method can be produced at a lower cost than when a heat source is arranged for each flow rate control unit.

Further, in the fluid control method and apparatus of the present invention, the flow path is formed in the microfluidic device, and the temperature of the liquid in the microfluidic device is controlled. Alternatively, by attaching a Peltier element and energizing the heater or Peltier element in the microfluidic device where temperature control is desired, the temperature rise and fall can be controlled locally. This makes it possible to independently control the temperature of a plurality of mixing units, reaction units, analysis units, and the like in the microfluidic device. The function of the heater is only heating, but since the size of each part of the microfluidic device is small, the heat dissipation rate is fast, and the temperature of the microfluidic device is immediately set by turning off the heater. The Peltier element can be heated and cooled by reversing the current flowing through the Peltier element, and the two-dimensionally arranged Peltier element group can independently control the temperature of each part of the microfluidic device.
In the fluid control method and apparatus of the present invention, the temperature of the flow path through which the liquid passes is changed to change the temperature of the liquid, thereby changing the viscosity of the liquid and changing the flow rate of the liquid. Therefore, liquid control can be realized with a simple structure as compared with the prior art. Thereby, there are few failures, it is cheap, and the apparatus can be miniaturized. Furthermore, in the prior art, stable variable control of the flow rate was difficult, but the fluid control method of the present invention can realize it.

  In addition, obstacles are installed inside the channel, the channel is installed on a curve, or the channel cross-sectional area of the temperature controlled part is smaller than the channel cross-sectional area of the other part In other words, the flow rate of the liquid is easily affected by the viscosity of the liquid, and the controllability of the flow rate of the liquid can be improved.

  Further, in the fluid control method of the present invention, by adjusting the pipe length of the flow path and the flow velocity, density, and viscosity of the liquid flowing in the flow path, the boundary condition is set so that the liquid is switched to a laminar flow state or a turbulent flow state. If the flow rate of the liquid is changed by changing the viscosity of the liquid by changing the temperature of the flow path or the liquid and changing the liquid from the laminar flow state to the turbulent flow state or vice versa, The flow rate can be changed rapidly. For example, by changing the liquid from a laminar flow state to a turbulent flow state, the flow rate can be extremely reduced. Since there is no linear or reversible relationship between the liquid temperature and the flow rate, it cannot be used for fine flow control, but when the liquid flow rate is to be drastically reduced under certain conditions, for example, This is particularly effective for a device for reducing fuel supply to an engine in an emergency.

  Further, if the relationship between the set temperature of the flow path or the liquid and the flow rate of the liquid is acquired in advance and a desired flow rate is obtained based on the data indicating the relationship, the controllability of the flow rate of the liquid is obtained. Can be improved.

  In addition, a plurality of the flow paths are formed by using a plurality of the flow paths that merge at the downstream junction, and controlling the flow rates of the liquids that flow through the flow paths by controlling the temperatures of the flow paths. If the ratio of the liquid supplied to the junction is controlled, for example, liquid or gas can be mixed at a desired ratio. Moreover, the ratio of the liquid to mix can also be changed by changing the temperature of a flow path.

It is the schematic which shows the whole structure of the apparatus used by one reference example. It is a figure which shows the side view and bottom view of the temperature control part of the apparatus shown in FIG. It is the schematic which shows the whole structure of the apparatus used by another reference example. It is a figure which shows the top view and side view of a liquid preparation part of the apparatus shown in FIG. It is a top view which shows the flow-path pattern of the glass part of the liquid adjustment part shown in FIG. It is a top view which shows the flow of the liquid in the mixing part of the glass part shown in FIG. 5 with the arrow. It is a figure which shows the top view and side view for demonstrating arrangement | positioning of the Peltier device and temperature sensing element in the glass part shown in FIG. It is a top view which shows the flow path pattern of the test | inspection chip used in one Example. It is a top view which shows roughly the heater arrangement | sequence of the temperature control member affixed on the test | inspection chip shown in FIG. FIG. 10 is a circuit diagram showing a heater arrangement of the temperature control member of FIG. 9 and an arrangement of transistors for controlling the heater. It is a top view which shows the state which affixed the temperature control member on the flow path pattern of a test | inspection chip. It is a top view which shows roughly the heater arrangement | sequence in a temperature control member. It is a top view which shows roughly the Peltier device arrangement | sequence in a temperature control member. It is a top view which shows the flow path pattern of the flow path plate of a test | inspection chip. It is a top view which shows the flow path pattern of the rotor plate of a test | inspection chip. It is a figure for demonstrating the valve | bulb of the flow-path plate of FIG. It is a top view of the measurement part of the Example. It is the top view and side view which show the state at the time of use of a test | inspection chip. It is a graph which shows the relationship between the temperature of water, and the change of a viscosity.

  Further, if the flow path is clogged by lowering the temperature of the flow path to solidify the liquid, the flow rate of the liquid can be cut off. Furthermore, the temperature of the flow path can be returned to the original or increased, and the solidified liquid can be liquefied to open the flow path. Thus, by changing the temperature of the flow path, the liquid in the flow path is solidified, and by melting the solidified liquid, the flow path itself can be used as a valve without providing a complicated structure in the flow path. Can function.

Reference Example 1: Daily Size Example: Ammonia Water Dilution Example The results of mixing ammonia water and pure water are listed. Ammonia water diluted with pure water is, for example, a liquid used for cleaning silicon wafers in the semiconductor industry. When this ammonia water is used for cleaning silicon wafers, particle mixing and trace amount of metal mixing are disliked, but in this embodiment, the wetted parts of pure water and ammonia water are only fluororesin, and the cleanliness of ammonia water Can be kept enough.

FIG. 1 is a schematic diagram showing the overall configuration of the apparatus used in this reference example.
A container 11 containing pure water and a container 12 containing ammonia water 26 wt% (weight percent) are provided.
One end of a PFA (tetrafluoroethylene-perfluoroalkylene ether ether copolymer) tube 17 is connected to a container 11 containing pure water. The PFA tube 17 is led to a temperature adjusting unit 13 for adjusting the liquid temperature in the PFA tube 17. The other end of the tube 17 is connected to the junction 19.
One end of a PFA tube 18 is connected to a container 12 containing ammonia water. The PFA tube 18 is led to a temperature adjusting unit 14 for adjusting the liquid temperature in the PFA tube 18. The other end of the tube 18 is connected to the junction 19.

FIG. 2 is a diagram showing a side view and a bottom view of the temperature adjustment unit of the apparatus shown in FIG. The temperature adjustment units 13 and 14 have the same structure.
For example, a PFA tube 17 (18) having an outer diameter of 3 mm (millimeters) and an inner diameter of 2 mm is wound around the bobbin 1 having a diameter of 60 mm 15 times. The length of the portion of the PFA tube 17 (18) wound around the bobbin 1 is about 2.8 m. A Peltier element plate 3 is attached to the upper surface of the bobbin 1. Radiating fins 4 are attached to the surface of the Peltier element plate 3 opposite to the bobbin 1. With a current flowing through the Peltier element plate 3, one side of the Peltier element is cooled and the other side is heated. The strength of the current determines the strength of the cooling and heating temperatures. When the direction of the current flowing through the Peltier element plate 3 is reversed, the heating and cooling plate surfaces are interchanged.

  Returning to FIG. 1, the description will be continued. One end of the PFA tube 19 is connected to the junction 19 to which the PFA tubes 17 and 18 are connected. The PFA tube 19 is guided to the pump 16 via a mixer 15 for mixing the liquid in the PFA tube 19. The pump 16 is a non-pulsating pump whose wetted part is made of PTFE (Poly Tetra Fluoro Ethylene).

The operation of diluting the pure water in the container 11 and the ammonia water in the container 12 will be described.
When the pump 16 is operated, pure water in the container 11 is sucked into the PFA tube 17 and ammonia water in the container 12 is sucked into the PFA tube 18. The pure water sucked into the PFA tube 17 is guided to the merging unit 19 via the temperature adjusting unit 13. The pure water and the ammonia water that have reached the junction 19 are guided into the PFA tube 20. The pure water and ammonia water introduced into the PFA tube 20 are completely mixed by the mixer 15 and then guided to the outlet side end portion of the PFA tube 20 through the pump 16. Diluted ammonia water is discharged from the outlet side end of the PFA tube 20.

  Tables 1 and 2 show the results of examining the mixing ratio of pure water and ammonia water by using the apparatus shown in FIG. Table 1 shows the ammonia concentration of diluted ammonia water, and Table 2 shows the flow rate (cc / sec). Here, the temperature adjusting unit 13 for adjusting the temperature of pure water and the temperature adjusting unit 14 for adjusting the temperature of the ammonia water were changed between 0 ° C. and 80 ° C., respectively. The suction force of the pump 16 was 0.001 MPa. With this flow rate, the Peltier element temperature in the temperature adjustment units 13 and 14 may be regarded as the temperature of the liquid that has passed through the temperature adjustment units 13 and 14. The flow rate is proportional to the pump suction force. At a flow rate where Peltier element temperature = liquid temperature, the ammonia concentration is not affected by the pump suction force.

  In this configuration, from Table 1, from an ammonia concentration of 4.1% at a temperature of 0 ° C. (freezing condition) on the ammonia water side and a temperature of 80 ° C. on the pure water side, a temperature of 80 ° C. on the ammonia water side and pure water The ammonia concentration can be changed between the ammonia concentration of 20.9% under the condition of the side temperature of 0 ° C. (freezing condition).

These follow Poiseuille's law.
Water side flow rate: Q1
Radius in water side tube: r1
Water side tube side length: L1
Water viscosity: η1
ΔP: Pressure drop at the inlet and outlet of the water side tube Q1 = π × r1 ⁴ × ΔP / (8 × η1 × L1)

Ammonia side flow rate: Q2
Radius inside ammonia side tube: r2
Ammonia side tube side length: L2
Ammonia viscosity: η2
ΔP: Pressure drop at the inlet and outlet of the ammonia side tube Q2 = π × r2 ⁴ × ΔP / (8 × η2 × L2)

If the ammonia stock solution concentration is a, the ammonia concentration (volume ratio) C is
C = a × Q2 / (Q1 + Q2)
It is. Since η1 and η2 are functions of the liquid temperature, the ammonia concentration C varies with temperature.

In the above example, laminar flow is used as a condition. However, when the Reynolds number Re (= (speed × length) / (viscosity × density)) is high, turbulent flow occurs.
In the configuration of the apparatus shown in FIG. 1, the boundary conditions for switching between laminar flow and turbulent flow are set by adjusting the flow rate of liquid, the pipe length in the temperature adjusting units 13 and 14, the density and viscosity of the liquid to be sent. The flow rate can be drastically reduced by raising the temperature of the liquid and decreasing the viscosity to change from a laminar flow state to a turbulent state. Since there is no linear and reversible relationship between the liquid temperature and the flow rate, it cannot be used for fine flow control, but when the liquid flow rate needs to be drastically reduced under certain conditions, for example, emergency It can be used as a fuel refueling reduction device for the engine.
Further, as an emergency liquid shutoff method, the liquid flow may be shut off by setting the temperature of the Peltier element in the temperature adjusting unit to zero and freezing the pipe.

Reference example 2: mm size reference example: methanol dilution example Direct methanol fuel cells (DMFCs) are attracting attention as small fuel cells for portable devices. A methanol aqueous solution having a methanol concentration of 3 to 5% is used for supplying fuel to the DMFC type fuel cell. When the methanol concentration is high, a crossover phenomenon occurs in which methanol unreacted at the fuel electrode passes through the electrolyte membrane and reaches the air electrode, resulting in a problem that power generation efficiency is reduced. Even if the methanol concentration is low, power generation efficiency decreases. Therefore, it is desired to always supply an optimal methanol concentration. In addition, if methanol with a high concentration can be diluted to an optimal concentration with water and used, the volume of methanol fuel stored in the DMFC fuel cell can be reduced. It can be made small. As water necessary for dilution, water generated on the air electrode side may be used, or humidity in the air may be collected.

FIG. 3 is a schematic diagram showing the overall configuration of the apparatus used in this reference example.
A tank 101 containing methanol with a concentration of 30% and a tank 102 containing water are provided.
One end of a tube 104 is connected to a tank 101 containing methanol. The other end of the tube 104 is connected to the liquid preparation unit 103. One end of a tube 105 is connected to a tank 102 containing water. The other end of the tube 105 is connected to the liquid preparation unit 103. A tube 108 for flowing diluted methanol mixed with methanol and water from the tubes 104 and 105 is also connected to the liquid preparation unit 103. Tube 108 is connected to pump 109.

FIG. 4 is a view showing a plan view and a side view of the liquid preparation unit of the apparatus shown in FIG.
The preparation unit 13 includes a glass part 111 in which a flow path is formed by etching of glass, a metal frame part 110 for supporting the glass part 111, and tubes 104, 105, and 108 in the glass part 111. Joints 112, 113, and 114 are provided for connection. The glass part 111 is a microfluidic device.

  The planar size of the glass part 111 is 12.5 mm × 39 mm, and the thickness is 2.2 mm. The frame 110 has an outer peripheral plane size of 19 mm × 46 mm, an inner peripheral plane size of 13 mm × 40 mm, and a thickness of 4.2 mm. Joints 112, 113, and 114 are inserted into the frame portion 110 with screws. The glass portion 111 disposed inside the frame portion 110 is fixed by being pressed down by the joints 112, 113, and 114. The glass part 111 is provided with a tapered concave part connected to the flow path inside the glass part 111 at a position corresponding to the joints 112, 113, and 114 on the side surface. By inserting the tips of the joints 112, 113, and 114 into the recesses on the side surface of the glass portion 111, the flow path is sealed to prevent liquid leakage.

  The glass part 111 has a three-layer structure in which a glass plate in which a groove for forming a channel is formed is sandwiched between two glass plates. The thickness of the glass plate which comprises a groove | channel is 0.2 mm. The thicknesses of the two glass plates for sandwiching the glass plates are each 1 mm.

FIG. 5 is a plan view showing a flow path pattern of the glass part 111.
A flow rate control unit 115 is provided in each of the two flow paths 125 and 126 to which the tubes 104 and 105 shown in FIG. 4 are connected. The flow rate control unit 115 includes four spiral channels connected in series. The flow path width, that is, the cross-sectional area of the flow rate control unit 115 is formed smaller than the other flow path portions of the glass unit 111. The flow path 125 and the flow path 126 are joined downstream of the flow rate control unit 115 and connected to the flow path 127. A mixing unit 116 is provided on the downstream side of the flow path 127.

FIG. 6 is a plan view showing the flow of the liquid in the mixing unit 116 with arrows.
The mixing unit 116 includes two wide portions 123 and 124. The upstream wide portion 123 and the downstream wide portion 124 are connected by two flow paths 128 and 129.

  A flow path 127 is connected to the wide portion 123 on the upstream side. A narrow portion 120 of the flow path is provided in the flow path 127 in the vicinity of the wide portion 123. The upstream end portions of the two flow paths 128 and 129 connecting the wide portions 123 and 124 are connected to the wide portion 123 at the locations adjacent to the narrow portion 120.

  A downstream flow path 130 is connected to a wide portion 124 on the downstream side. The downstream end portions of the two flow paths 128 and 129 connecting the wide portions 123 and 124 are connected to the wide portion 124 at the positions on both sides of the flow path 130. In the vicinity of the wide portion 124, narrow portions 121 and 122 are provided in the flow channels 128 and 129.

The liquid introduced from the flow path 127 through the narrow portion 120 to the wide portion 123 has a high flow velocity at the thin portion 120, and thus generates vortices in the wide portion 123 (see arrows). The liquid introduced from the wide part 123 to the wide part 124 through the two flow paths 128 and 129 connecting the wide parts 123 and 124 and the narrow parts 121 and 122 of the flow path flows at the narrow parts 121 and 122. Becomes faster, so a vortex is generated in the wide portion 124 (see arrow). These vortices promote liquid mixing.
As shown in FIG. 5, since the mixing unit 116 is provided in two stages, the liquid is completely mixed by repeating the mixing pattern shown in FIG. 6 in two stages.

FIG. 7 is a diagram illustrating a plan view and a side view for explaining the arrangement of the Peltier elements and the temperature measuring elements in the glass portion 111.
Two Peltier elements 118 and 119 are attached to the upper surface of the glass part 111. The Peltier element 118 is disposed on the flow rate control unit 115 through which methanol flows. The Peltier element 119 is disposed on the flow rate control unit 115 through which water flows.
Two temperature measuring bodies 132 and 133 are attached to the lower surface of the glass part 111. The temperature measuring elements 132 and 133 are made of, for example, platinum. The temperature measuring element 132 is disposed under the flow rate control unit 115 through which methanol flows. The temperature measuring body 133 is disposed under the flow rate control unit 115 through which water flows.
In FIG. 4, illustration of the Peltier elements 118 and 119 and the temperature measuring elements 132 and 133 is omitted.

The operation of diluting methanol will be described with reference to FIGS.
When the pump 109 is operated, the methanol in the container 101 is sucked into the tube 104 and the water in the container 102 is sucked into the tube 105. Methanol sucked into the tube 104 and water sucked into the tube 105 are guided to the liquid preparation unit 103. The methanol and water guided to the liquid preparation unit 103 merge after passing through the flow rate control unit 115 of the glass unit 111, and are guided to the mixing unit 116 and mixed to become diluted methanol. The diluted methanol is guided from the glass part 111 to the tube 108 and discharged through the pump 109.

When the concentration of diluted methanol is higher than 4%, control is performed to increase the flow rate on the water side and decrease the flow rate on the methanol side. Specifically, by increasing the temperature of the Peltier element 119 on the water side, the viscosity of water is decreased and the flow rate is increased. Further, by lowering the temperature of the Peltier element 118 on the methanol side, the viscosity of methanol is increased and the flow rate is decreased. The temperatures of the Peltier elements 118 and 119 are measured by temperature measuring elements 132 and 133, respectively.
Table 3 shows the relationship between methanol temperature, water temperature and methanol concentration obtained by this method.

Since the methanol temperature is close to the measured value of the temperature measuring element 132 of the methanol side Peltier element 118 and the water temperature is close to the measured value of the temperature measuring body 133 of the water side Peltier element 119, the methanol temperature and water temperature in Table 3 are measured. The measured values of the warm bodies 132 and 133 can be substituted.
Thereby, the methanol concentration can be controlled to 4% by adjusting the temperatures of the water side Peltier element 119 and the methanol side Peltier element 118.

  In this reference example, a Peltier element is used as a material for changing the liquid temperature, but a heater may be used. In that case, independent surface-controllable surface heaters are affixed on the flow rate control unit 115 of the glass unit 11. The lower surface of the glass part 11 is installed on a heat sink. As the heater is turned on, the temperature of the flow control unit 115 increases, and the temperature of the liquid flowing through the flow control unit 115 also increases. A temperature measuring element is installed near the surface heater, and the heater is feedback-controlled based on temperature information from the temperature measuring element. If the current passed through the heater is lowered, the temperature will drop to accommodate the heat sink temperature due to heat dissipation. When the size is on the order of millimeters, the surface area side is overwhelmingly large due to the ratio of the surface area to the volume of the object. Therefore, it is possible to sufficiently control the temperature only with a heating element using a heater.

  In this reference example, the mixing unit 116 is performed by passing a maze-like pattern. However, as a mixing method, a method of arranging an obstacle in a flow path or irradiating the liquid with ultrasonic waves from an ultrasonic element. There is also a method of mixing.

Example 1: Example of micron size: Test chip as a microreactor (microfluidic device) An example in which the fluid control method of the present invention is used in an analysis system using a microreactor will be described. The flow path of the inspection chip is formed on the substrate according to the purpose. Here, the fluid is a liquid. The flow path formed in the inspection chip is a fine flow path having a width and a depth of about 50 to 200 μm. The flow path can be formed in a large amount by transferring a mold formed by photolithography technique and etching technique onto a resin. For example, polystyrene or polydimethylsiloxane is used as the resin.

FIG. 8 is a plan view showing a flow path pattern of the inspection chip.
The flow rate control unit in the flow path pattern formed on the inspection chip 300 is obtained by further miniaturizing the flow path pattern of the glass part 111 shown in FIG. In such a case, each flow control unit may be provided with a Peltier element or a heater for changing the temperature.

  However, since such inspection chips are required to reduce costs by mass production, the flow path pattern changes for each type of inspection chip, and the positions of the Peltier elements and heaters also change. Designing the arrangement is expensive.

  Therefore, a temperature control member in which Peltier elements or heaters are two-dimensionally arranged was created. The temperature control member has a planar size that is the same as or slightly larger than the inspection chip size area, or at least the same or slightly larger than the area of the portion of the inspection chip where temperature control is desired. Then, the temperature control member is attached to the inspection chip. After affixing the temperature control member, the positional relationship between the flow rate control unit in the inspection chip and the Peltier element or heater in the temperature control member is obtained using an inspection jig such as a microscope. The obtained address data is stored in a microcomputer memory with a built-in inspection chip, for example. The microcomputer controls the temperature of a desired portion of the temperature control member, and thus a desired portion of the inspection chip, based on the data.

  FIG. 9 is a plan view schematically showing the heater arrangement of the temperature control member. FIG. 10 is a circuit diagram showing the heater arrangement of the temperature control member and the arrangement of the transistors for controlling the heater.

  The temperature control member 388 in which the heater and the transistor are two-dimensionally arranged is formed on the silicon substrate using a semiconductor device manufacturing process. For example, a total of 4096 heaters r <b> 1-1 to r <b> 64-64 389 is formed with 64 in the X-axis direction and 64 in the Y-axis direction. The heater can be manufactured by adding a metal impurity to silicon to form a semiconductor and passing a current therethrough. In order to control on / off of each heater, a transistor is provided for each heater.

  In the operation of the circuit shown in FIG. 10, a voltage is applied to the bases (or gates) of the transistors t0-1 and t0-2 in order from the electrode h1 to the electrode h2, and the transistors are turned on. The electrode 502 is supplied with a power supply voltage for supplying a current to each heater ri-j (i is 1 to 64, j is 1 to 64). A 5V voltage is applied to the electrode h1 for 1 millisecond, and after it is set to 0V, a 5V voltage is applied to the electrode h2 for 1 millisecond. The same is repeated with the electrodes h2, h3,..., H64, and up to the electrode h64, the process returns to the electrode h1, and the cycle is repeated.

A voltage for turning on the transistor ti-j (i is 1 to 64, j is 1 to 64) is applied to the electrode 501. When a voltage is applied to the electrode h1 and the transistor t0-1 is on, the transistor ti-1 (i is 1 to 64) is a control target.
The electrode rei (i is 1 to 64) is connected to the base of the transistor tri-0 (i is 1 to 64), and the transistor tri-0 (i is 1 to 64) is turned on / off depending on whether a voltage is applied thereto. Off is decided.
The electrode vi (i is 1 to 64) is connected to the base of the transistor ti-0 (i is 1 to 64), and the transistor ti-0 (i is 1 to 64) is turned on depending on whether a voltage is applied thereto. / OFF is decided.

  For example, when it is desired to pass a current through the heater r1-1, the transistor tr1-0 is turned off, the transistor t1-0 is turned on, and the transistor t1-1 is turned on only while the transistor t0-1 is turned on. In order to cut off the current flowing through the heater r1-1, the transistor tr1-0 is turned on, the transistor t1-0 is turned off, and the transistor t1-1 is turned off.

  By such an operation, on / off of each heater ri-j (i is 1 to 64, j is 1 to 64) can be controlled. By changing the ratio of the ON time and OFF time of each heater ri-j (i is 1 to 64, j is 1 to 64), the heater ri-j (i is 1 to 64, j is 1 to 64) The power supply amount can be controlled, and the temperature of the heater ri-j (i is 1 to 64, j is 1 to 64) can be individually controlled. Thereby, the temperature of the desired location in the heater array 389 of the temperature control member 388, and thus the desired location of the inspection chip can be controlled.

  If the heater ri-j (where i is 1 to 64, j is 1 to 64) is replaced with a Peltier element or LED, a Peltier element arranged two-dimensionally in the same manner as described with reference to FIGS. And LED on / off can be individually controlled. Also in this case, the temperature of the desired location of the temperature control member, and hence the desired location of the inspection chip can be controlled.

  FIG. 11 is a plan view showing a state in which the temperature control member 388 is attached to the flow path pattern of the inspection chip 300. FIG. 11 shows only the heater array 389 for the temperature control member 388.

  After the temperature control member 388 is affixed to the inspection chip 300 in mass production, the heater address of the location overlapped with the flow rate control unit of the flow path pattern is obtained in an inspection process using a microscope. The address data is stored in the memory of the accompanying microcomputer. The microcomputer is programmed to turn on / off only the addressed heater. Heaters that are not arranged on the flow control unit are wasted. However, design costs and initial costs can be reduced as total costs. Furthermore, this method can produce inspection chips at a lower cost than when a heater is provided for each flow rate control unit.

  If the flow control unit is the only part that requires temperature control in the inspection chip, heaters that are not arranged on the temperature control unit out of the two-dimensionally arranged heaters are wasted. However, in a microfluidic device, there are many places where temperature management is necessary. For example, a polymerase chain reaction (PCR) is performed in a microreactor (micro reaction vessel) for detecting a nucleic acid sequence provided inside a microfluidic device. In that case, first, the enzyme and the primer are mixed with the sample solution and stored in the microreactor. The inside of the microreactor is heated at 94 ° C. for 1 minute, and then rapidly cooled to about 60 ° C. and annealed. Thereafter, the inside of the microreactor is heated to 65 ° C. and kept for 1 minute, and the temperature control cycle for returning to 94 ° C. is repeated about 20 times. A plurality of microreactors are installed in one inspection chip, and the reaction proceeds in parallel. The mixing ratio of the enzyme, primer and sample liquid can be reliably performed by the fluid control method of the present invention. Furthermore, if a temperature control member in which heaters and the like are two-dimensionally arranged is also arranged on the microreactor, PCR temperature management can also be performed using the temperature control member.

  Further, the heater may be changed to a Peltier element. When a Peltier element is used, cooling can be performed by reversing the current flowing through the Peltier element. In this case, the flow path that is to be completely closed in the inspection chip can be realized by freezing the liquid in the flow path.

  The heater array may be an LED array. In this case, by using an LED that emits light having a wavelength that is absorbed by the fluid whose temperature is to be increased, by using a resin that does not absorb much light emitted by the LED as a resin that is the base material of the test chip, Efficient heat transfer is possible.

  In this embodiment, the flow path closing process by the freezing of the liquid by the cooling by the Peltier element is actively used. The Peltier element can realize heating and cooling with one element by current reversal. However, when the Peltier elements are arranged two-dimensionally, if one Peltier element has a heating function and a cooling function, the circuit becomes complicated. Therefore, in this embodiment, a temperature control member in which a Peltier element for heating and a Peltier element for cooling are two-dimensionally arranged is used. However, a circuit may be formed so that one Peltier element has a heating function and a cooling function.

FIG. 12 is a plan view schematically showing a heater arrangement in the temperature control member. FIG. 13 is a plan view schematically showing a Peltier element arrangement in the temperature control member.
As shown in FIG. 13, a cooling side Peltier element 512 and a heating side Peltier element 513 are installed in one portion 511 of the heater array in FIG. 12. In this case, two circuits for controlling the cooling side Peltier element 512 and the heating side Peltier element 513 are the same as those shown in FIG. This temperature control member is attached to the inspection chip 300 in the same manner as the temperature control member 388 shown in FIG.

FIG. 14 is a plan view showing a flow path pattern of the flow path plate 304 of the inspection chip. FIG. 15 is a plan view showing a flow path pattern of the rotor plate 305 of the inspection chip.
The inspection chip 300 shown in FIG. 8 is roughly composed of a flow path plate 304 shown in FIG. 14, a rotor plate 305 shown in FIG. 15, and a temperature control member 388 shown in FIG.

  A flow path and a space for flowing or containing a liquid or gas are formed in the flow path plate 304. The rotor plate 305 is attached to one surface of the flow path plate 304. A temperature control member in which a cooling side Peltier element and a heating side Peltier element are two-dimensionally arranged is attached to the back surface of the flow path plate 304 in the same manner as the temperature control member 388 shown in FIG.

  In the flow path plate 304, reagents are sealed as liquids in the spaces 319, 335, 351, and 367. The flow paths 317, 320, 336, 352, 368, 333, 349, and 365 have a constant pattern, in this case, a spiral flow path pattern in order to increase the length of the narrow flow path. This is the same as the flow rate control unit 115 of the second embodiment, and the flow rate is controlled by changing the viscosity of the fluid passing through this flow path at the temperature set by the Peltier element corresponding to these positions. In the initial state, water is sealed.

Spaces 321, 337, 353, and 369 of the flow path plate 304 are stirring portions. Inside them, a fine resin-coated magnet bar is enclosed.
Rotor accommodating portions 330, 346, 362, and 378 are provided on the rotor plate 305 corresponding to the positions of the spaces 321, 337, 353, and 369. Rotators 329, 345, 361, and 377 with magnets that are rotated by a gas flow are accommodated therein. Gas inlet side channels 328, 344, 360, 376 and gas outlet side channels 331, 347, 363, 379 are connected to the rotor accommodating portions 330, 346, 362, 378. The gas inflow channels 328, 344, 360, and 376 are connected to the channels 327, 343, 359, and 375 of the channel plate 304. The gas discharge side flow paths 331, 347, 363, 379 are joined and connected to the gas discharge port 332. By rotating the rotors 329, 345, 361, and 377 with magnets, the magnet rods accommodated in the spaces 321, 337, 353, and 369 rotate, and the liquid in the spaces 321, 337, 353, and 369 is discharged. Stir.

  In the flow path plate 304, the flow paths 314, 322, 338, 354, 370, and 386 are narrower than the front and rear flow paths. The flow paths 314, 322, 338, 354, 370, and 386 are portions that freeze the fluid in the flow paths and close the flow paths by cooling the Peltier elements corresponding to the positions of these flow paths.

Reference numerals 316, 318, 324, 326, 334, 340, 342, 350, 356, 358, 366, 372, and 374 are valves that close the flow path in the initial state.
FIG. 16 is a view for explaining a valve of the flow path plate.
Reference numeral 400 denotes a ball. In a state where pressure is applied from the flow path 401 to a portion in which the ball 400 is accommodated, the ball 400 is stopped by a resin nail. Thereby, the ball 400 blocks the flow path. This state is the initial state of the valve. By heating the Peltier element directly below the ball 400, the resin claws are softened, and the ball 400 moves to the space 405 under pressure. Three flow paths 402, 403, and 404 are connected to the space 405. The flow paths 402, 403, and 404 are joined by a downstream flow path 406. Accordingly, the fluid flows from the flow path 401 toward the flow path 405 regardless of the position of the ball 400 in the space 405.

  Pressurized gas is introduced from the gas inlet 302 of the flow path plate 304. This may be a supply from a high-pressure air cylinder, a supply from an air pump, or a carbon dioxide supply from a container enclosing a foamable liquid such as carbonated water.

FIG. 17 is a plan view and a side view showing a state when the inspection chip is used.
A microcomputer 521 is attached to one side surface of the inspection chip 300. A rotor plate 305 is attached to one surface of the flow path plate 304. A temperature control member 388 is attached to the back surface of the flow path plate 304.
The plane size of the inspection chip 300 including the microcomputer 521 is 22 mm × 20 mm. In the temperature control member 388, the planar size of the two-dimensional array 389 of the cooling side Peltier elements and the heating side Peltier elements is 11 mm × 11 mm.

An example in which a test sample 300 is used to test a nucleic acid sequence of a specimen will be described.
(1) In detecting the nucleic acid sequence, the microcomputer 521 is operated by the switch. The microcomputer 521 cools the Peltier element at a position corresponding to the flow path 317 of the flow path plate 304. Thereby, the water in the flow path 317 is frozen, and the flow path 317 is closed.

(2) Reference numeral 301 of the flow path plate 304 is an insertion port of a syringe needle. The blood sample collected by the syringe is inserted into the hole of the insertion port 301 and the blood sample is injected. Reference numeral 307 denotes a check valve made of nitrile rubber. Reference numeral 306 is a crow mouth, and the liquid proceeds from the reference numeral 306 in the direction of the flow path 308, but the reverse does not proceed. The blood sample passes through the space 309, the flow path 310 and the space 311, passes through the narrower flow path 314, and then enters the space 315. The space 309 is preliminarily filled with a blood coagulation preventing agent. The space 315 is filled with a liquid adsorption resin. The space 315 communicates with the atmosphere through the exhaust port 303. The blood sample is adsorbed by the resin in the space 315 so that excess liquid does not leak out. Since the flow path plate 304 is transparent to the extent that the inside can be visually confirmed, the operator can visually confirm the state of blood injection. If the spaces 309 and 311 are replaced with red blood, it can be determined that the blood sample injection is successful.

(3) The space 319 is filled with a surfactant as a pretreatment reagent. When the inspection chip 300 is used, the space 319 is heated or cooled in advance. This is because the viscosity of the liquid in the space 319 is controlled in advance before the liquid in the space 319 is introduced into the flow path 320. When reducing the flow rate of the liquid introduced from the space 319 into the flow path 320, the space 319 is cooled. When the flow rate is increased, the space 319 is heated.
(4) The Peltier element at a position corresponding to the flow paths 314 and 333 is cooled, and the fluid in the flow paths 314 and 333 is frozen to close the flow paths 314 and 333.
(5) The Peltier element at a position corresponding to the flow path 317 is set to room temperature, and the flow path 317 is opened.

(6) The Peltier element at a position corresponding to the valves 316 and 318 is heated to open the valves 316 and 318. Pressurized gas flows from the gas inlet 302, and the space 311 is pressurized via the valve 316 and the flow path 312. The blood in the space 311 flows through the flow paths 313 and 317 and flows into the agitation 321. In addition, the reagent in the space 319 passes through the flow path 320 and flows into the agitation 321. The excess liquid of blood and reagent passes through the flow paths 322 and 323, enters the space 315, and is adsorbed by the liquid adsorption resin. Here, since the check valve 307 has a backflow prevention function, the blood in the space 311 does not flow back to the flow path 310 side. Further, since the flow path 314 is frozen and closed, the blood in the space 311 does not go to the space 315 side. In addition, the temperature of the Peltier element at the position corresponding to the flow paths 317 and 320 is controlled so that the mixing ratio of the reagent and blood becomes a predetermined ratio.

(7) The Peltier element at a position corresponding to the flow paths 317 and 320 is cooled, and the fluid in the flow paths 317 and 320 is frozen to close the flow paths.
(8) The Peltier element at a position corresponding to the valve 326 is heated to open the valve 326. The pressurized gas passes through the hole of the flow path 327 via the valve 326 and reaches the gas inflow side flow path 328 of the rotor plate 305. The gas that has flowed into the rotor accommodating portion 330 from the gas inflow side flow path 328 rotates the rotor 329 clockwise. Then, the gas passes through the gas discharge channel 331 and is released from the gas discharge port 332 to the atmosphere.
(9) Since the magnet is embedded in the rotor 329, the minute bar magnet accommodated in the space 321 is rotated by the rotation of the rotor 329. Thereby, the liquid and the reagent in the space 321 are stirred.

(10) The Peltier element at the position corresponding to the space 321 is heated and heated to 98 ° C. for 1 minute. Here, DNA in leukocytes is extracted and becomes a single strand. Thereafter, the temperature is set to 25 ° C.
(11) In the space 335, a mixture of a catalyst such as magnesium chloride, a buffer solution such as a phosphate buffer, and a nucleobase necessary for amplification is enclosed as a reaction amplification reagent. When the inspection chip 300 is used, the space 335 is heated or cooled in advance. This is because the viscosity is adjusted in advance by controlling the temperature of the liquid in the space 335 before the liquid in the space 335 is introduced into the flow path 336. In order to reduce the flow rate of the liquid introduced from the space 335 into the flow path 336, the space 335 is cooled. Further, when the flow rate is increased, the space 335 is heated.
(12) The Peltier element at a position corresponding to the flow paths 322 and 349 is cooled, the fluid in the flow paths 322 and 349 is frozen, and the flow path 349 is closed.
(13) The Peltier element at a position corresponding to the flow path 333 is set to room temperature, and the flow path 333 is opened.

(14) The Peltier element at a position corresponding to the valves 324 and 334 is heated to open the valves 324 and 334. Pressurized gas flows from the gas inlet 302 and the space 321 is pressurized through the valve 324 and the flow path 325. The liquid in the space 321 flows through the flow path 333 and flows into the space 337. The reagent in the space 335 passes through the flow path 336 and flows into the space 337. Each excess liquid passes through the flow paths 338 and 339, enters the space 315, and is adsorbed by the liquid adsorption resin. The temperature of the Peltier element at the position corresponding to the flow paths 333 and 336 is controlled so that the mixing ratio of the reagent in the space 335 and the liquid in the space 321 becomes a predetermined ratio.

(15) The Peltier element at a position corresponding to the flow paths 336 and 333 is cooled, the fluid in the flow paths 333 and 336 is frozen, and the flow paths 333 and 336 are closed.
(16) The Peltier element at a position corresponding to the valve 342 is heated to open the valve 342. The pressurized gas passes through the hole of the flow path 343 and reaches the gas inflow side flow path 344 of the rotor plate 305. The gas that has flowed into the rotor accommodating portion 346 from the gas inflow side flow path 344 rotates the rotor 345 clockwise. Then, the gas passes through the gas discharge channel 347 and is released from the gas discharge port 332 to the atmosphere.
(17) Since a magnet is embedded in the rotor 345, the minute bar magnet accommodated in the space 337 is rotated by the rotation of the rotor 345. Thereby, the liquid and the reagent in the space 337 are stirred.

(18) The temperature of the Peltier element at a position corresponding to the space 337 is adjusted to bring the temperature in the space 337 to a 25 ° C. state.
(19) The space 351 contains a heat-resistant DNA polymerase as an enzyme. When the inspection chip 300 is used, the space 351 is heated or cooled in advance. This is because the viscosity is adjusted by controlling the temperature of the liquid in the space 351 in advance before the liquid in the space 351 is introduced into the flow path 352. In order to reduce the flow rate of the liquid introduced from the space 351 into the flow path 352, the space 351 is cooled. In addition, when the flow rate is increased, the space 351 is heated.
(20) The Peltier element at a position corresponding to the flow paths 338 and 365 is cooled, the fluid in the flow paths 338 and 365 is frozen, and the flow path 365 is closed.
(21) The Peltier device at a position corresponding to the flow path 349 is set to room temperature, and the flow path 349 is opened.

(22) The Peltier element at a position corresponding to the valves 340 and 350 is heated to open the valves 340 and 350. Pressurized gas from the valve 340 flows, and the space 337 is pressurized through the valve 340 and the flow path 341. The liquid in the space 337 flows through the flow path 349 and into the space 353. The reagent in the space 351 passes through the flow path 352 and flows into the space 353. Each excess liquid passes through the flow paths 354 and 355, enters the space 315, and is adsorbed by the liquid adsorption resin. The temperature of the Peltier element at positions corresponding to the flow paths 352 and 349 is controlled so that the mixing ratio of the reagent in the space 351 and the liquid in the space 337 becomes a predetermined ratio.

(23) The Peltier element at the position corresponding to the flow paths 349 and 352 is cooled, the fluid in the flow paths 349 and 352 is frozen, and the flow paths 349 and 352 are closed.
(24) The Peltier element at a position corresponding to the valve 358 is heated to open the valve 358. The pressurized gas passes through the hole of the flow path 359 and reaches the gas inflow side flow path 360 of the rotor plate 305. The gas that has flowed into the rotor accommodating portion 362 from the gas inflow side flow path 360 rotates the rotor 361 clockwise. The gas passes through the gas discharge channel 363 and is released from the gas discharge port 332 to the atmosphere.
(25) Since the magnet is embedded in the rotor 361, the minute bar magnet accommodated in the space 353 is rotated by the rotation of the rotor 361. Thereby, the liquid and the reagent in the space 353 are agitated.

(26) The temperature of the Peltier element at a position corresponding to the space 353 is adjusted to bring the temperature in the space 353 to a 25 ° C. state.
(27) The space 367 contains a target DNA primer. When the inspection chip 300 is used, the space 367 is heated or cooled in advance. This is because the viscosity of the liquid in the space 367 is controlled in advance before the liquid in the space 367 is introduced into the flow path 368. In order to reduce the flow rate of the liquid introduced from the space 367 into the flow path 368, the space 367 is cooled. When the flow rate is increased, the space 367 is heated.
(28) The Peltier element at a position corresponding to the flow path 354 is cooled, the fluid in the flow path 354 is frozen, and the flow path 354 is closed.
(29) The Peltier device at a position corresponding to the flow path 365 is set to room temperature, and the flow path 365 is opened.

(30) The Peltier element at a position corresponding to the valves 356 and 366 is heated to open the valves 356 and 366. Pressurized gas from the valve 356 flows, and the space 353 is pressurized through the valve 356 and the flow path 357. The liquid in the space 353 flows through the flow path 365 and into the space 369. The reagent in the space 367 passes through the flow path 368 and flows into the space 369. Each excess liquid passes through the flow paths 370 and 371, enters the space 315, and is adsorbed by the liquid adsorption resin. The temperature of the Peltier element at the position corresponding to the flow paths 368 and 365 is controlled so that the mixing ratio of the primer in the space 367 and the liquid in the space 353 becomes a predetermined ratio.

(31) The Peltier element at a position corresponding to the flow paths 365 and 368 is cooled, and the fluid in the flow paths 365 and 368 is frozen to close the flow paths 365 and 368.
(32) The Peltier element at a position corresponding to the valve 374 is heated to open the valve 374. The pressurized gas passes through the hole 375 and reaches the gas inflow side flow path 376 of the rotor plate 305. The gas that has flowed into the rotor accommodating portion 378 from the gas inflow side flow passage 376 rotates the rotor 377 clockwise. Then, the gas passes through the gas discharge channel 379 and is released from the gas discharge port 332 to the atmosphere.
(33) Since the magnet is embedded in the rotor 377, the minute bar magnet accommodated in the space 369 is rotated by the rotation of the rotor 377. Thereby, the liquid and the reagent in the space 369 are agitated.

(34) The temperature of the Peltier element at the position corresponding to the space 369 is adjusted to bring the temperature in the space 369 to 94 ° C. for 1 minute, and then rapidly cooled to about 60 ° C. and annealed. Thereafter, the temperature control cycle is maintained at 65 ° C. for 1 minute and then returned to 94 ° C., for example, 20 times. Thereafter, the temperature is set to 25 ° C.
(35) The Peltier element at a position corresponding to the flow path 370 is cooled, the fluid in the flow path 370 is frozen, and the flow path 370 is closed.

(36) The Peltier element at a position corresponding to the valve 372 is heated to open the valve 372. Pressurized gas from the valve 372 flows, and the space 369 is pressurized through the valve 372 and the flow path 373. The liquid in the space 369 passes through the flow path 386 and enters the space 387. Excess liquid enters the space 315 and is adsorbed by the liquid adsorption resin. In the space 387, a fluorescent reagent is sealed in advance. If this fluorescent reagent has target DNA, the fluorescence is suppressed.
(37) irradiate light having a wavelength of 490 nm in the space 387 and measure the fluorescence intensity of 520 nm to detect whether there is amplification of the target DNA.
Thereby, the nucleic acid sequence inspection is completed.

  As mentioned above, although the Example of this invention was described, material, a shape, arrangement | positioning, etc. are examples, this invention is not limited to these, Various within the range of this invention described in the claim Can be changed.

  For example, in the above embodiment, a Peltier element or a heater is used as a heat source for changing the temperature of the flow path, but the temperature of the flow path may be changed by irradiating the flow path with light. Examples of the light source for irradiating the flow path with light include an LED and a semiconductor laser. Alternatively, a light source and an optical fiber may be used, and light entering the incident end of the optical fiber from the light source may be emitted from the output end of the optical fiber, and light may be irradiated to the flow path to change the temperature of the flow path.

3 Peltier element plate 11 Container 12 containing pure water Container 13, 14 containing ammonia water Temperature adjusting unit 17, 18 PFA tube (flow path)
19 Junction part 111 Glass part (microfluidic device)
115 Flow control unit (flow path)
118,119 Peltier device 300 Inspection chip (microfluidic device)
310, 314, 317, 320, 322, 333, 336, 338, 349, 352, 354, 365, 368, 370, 386 Channel 389 Two-dimensional array of heaters or Peltier elements

Claims (13)

In the fluid control method for controlling the flow rate of the fluid in the flow path by changing the viscosity of the fluid by changing the temperature of the liquid flowing in the flow path,
The flow path is formed in the microfluidic device, and has a flow rate control unit for changing the temperature of the liquid flowing in the flow path.
A temperature control member in which more heat sources than the number of the flow rate control units existing in the microfluidic device are arranged in a two-dimensional array is provided on the microfluidic device,
A fluid that controls the flow rate of the liquid flowing in the flow path via the corresponding flow rate control unit by selectively operating a heat source disposed on the flow rate control unit among the heat sources. Control method.   The fluid control method according to claim 1, wherein the heat source is a heater, a Peltier device, an LED, or a semiconductor laser. The temperature control member is one in which the heat sources are arranged along a direction orthogonal to each other in a plane,
Holds address data indicating the position of the heat source arranged on the flow rate control unit,
The fluid control method according to claim 1, wherein the heat source is selectively operated based on the address data. The temperature control member has a Peltier element as the heat source,
The fluid control method according to any one of claims 1 to 3, wherein the flow rate control unit clogs the flow rate by lowering the temperature of the liquid to solidify the liquid to block the flow rate of the liquid.   Adjusting the flow length, density and viscosity of the liquid flowing in the flow path, and setting the boundary conditions for the liquid to switch to a laminar flow state or a turbulent flow state; 5. The flow rate of the liquid is changed by changing the viscosity of the liquid by changing the temperature of the liquid to change the liquid from a laminar flow state to a turbulent flow state or vice versa. Fluid control method.   The fluid control method according to any one of claims 1 to 4, wherein a relationship between a set temperature of the flow path and a flow rate of the liquid is acquired in advance, and a desired flow rate is obtained based on data indicating the relationship. . The microfluidic device is provided with a flow path configuration in which a plurality of flow paths merge into one flow path at a merge portion,
By controlling the temperature of the flow rate control unit in the flow channel upstream of the merging unit and controlling the flow rate of the liquid flowing in the flow channel, the liquid supplied to the merging unit from a plurality of the flow channels The fluid control method according to any one of claims 1 to 4, wherein the ratio is controlled. A microfluidic device having at least one flow path having a flow rate controller for changing the temperature of the liquid flowing in the flow path;
A temperature control member provided on the microfluidic device and having a heat source more than the number of the flow rate control units existing in the microfluidic device arranged in a two-dimensional array,
The fluid control apparatus which controls the flow volume of the liquid which flows through the said flow path through the said flow control part by selectively operating the heat source arrange | positioned on the said flow control part among the said heat sources.   The fluid control device according to claim 8, wherein the heat source is a heater, a Peltier element, an LED, or a semiconductor laser. A microcomputer for controlling the flow rate of the liquid flowing in the flow path;
The temperature control member is one in which the heat sources are arranged along a direction orthogonal to each other in a plane,
10. The microcomputer holds address data indicating the position of the heat source arranged on the flow rate control unit, and selectively activates the heat source based on the address data. The fluid control apparatus described.   The fluid control device according to claim 9 or 10, wherein the flow rate control unit is formed so that a flow path cross-sectional area is smaller than a flow path cross-sectional area of another part.   The fluid control device according to any one of claims 9 to 11, wherein the flow path is formed by removing a part of a glass member, a semiconductor member, or a metal member by an etching technique.   The fluid control device according to claim 9, wherein the flow path is formed by transferring a mold formed by a photolithography technique and an etching technique onto a resin.

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