JP2010175407A - Fluid physical property meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently, accurately, and stably measure a concentration of fluid, especially liquid in a channel of a chip in which the channel having a fine size is formed. <P>SOLUTION: A fluid physical property meter has a chip holding part 110 for holding the chip 111 in which the channel is formed by forming a through groove for forming the channel in a partition plate having a uniform thickness and holding the partition plate between two light-transmitting planar plates. The fluid physical property meter is provided with both a light irradiation part for irradiating the channel of the chip 111 with light and a movement mechanism member 201 for supporting a light-receiving part for receiving light transmitted through the channel. The fluid physical property meter is provided with sliders 202 and 203 for relatively moving the movement mechanism member 201, the chip holding part 110, and the chip 111. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fluid property measuring meter, and in particular, a fluid for measuring physical properties of a fluid in a flow path of a chip such as a microarray, a microanalysis system, a DNA chip, a microfluidic system, and an integrated small analysis system (μTAS). It relates to a physical property meter.

A flow path in a chip such as a microfluidic system is formed by covering a groove formed on the substrate by an etching technique or the like with another substrate (see, for example, Patent Document 1). In a microfluidic system, it is common to check whether a fluid process is proceeding as planned, at the time of designing a microfluidic system or at a prototype stage. Depending on the target process, conditions such as fluid flow rate, flow velocity, installation temperature, valve opening and closing time are determined. After that, the same product will be mass-produced as much as possible, and the system will be operated under the originally determined conditions.
JP-T-2001-509260 JP 2007-155494 A

  In reality, however, the channel dimensions of the microfluidic system vary greatly depending on the etching conditions. Originally, since the flow path of the microfluidic system has a size in the micron region, even if the etching error is on the micron order, the error ratio becomes considerably large. Therefore, the flow rate and flow rate of the fluid vary greatly depending on the production lot. Even if the producer intends to make the same thing, the results obtained even if operated under the same conditions may vary greatly.

  In addition, the physical characteristics of the fluid may change every moment. Specifically, this is the case where the flow rate changes significantly due to the change in the viscosity of the liquid. Since the viscosity of the liquid depends on the temperature, the viscosity of the liquid and thus the flow rate of the liquid change depending on a change in the environmental temperature in which the microfluidic system is installed and a change in the temperature of the fluid itself. In addition, when the fluid is a volatile liquid, the solvent is volatilized every time and the concentration increases, and the viscosity may increase.

  For that reason, a sensor may be provided in the microfluidic system as a confirmation of whether the process is proceeding normally at the end of the process. However, there are limited precision sensors that can be micronized, the microfluidic system manufacturing process is complicated and expensive to install, and the failure frequency increases due to complexity. There were problems such as a decrease in reliability.

  In addition, a flow cell having a first space and a second space that are isolated from each other is used, and light generated from a light source is incident on the flow cell, and is a part of an optical path that guides light transmitted through the flow cell to a light receiving element. A spectrophotometer is disclosed that can move the position of one end and the second end from a position that transmits light to one of the first space and the second space of the flow cell to a position that transmits light to the other. (See Patent Document 2).

  The present invention relates to a fluid property measuring instrument in a flow path of a chip in which a micro-sized flow path is formed inside, such as a microarray, a microanalysis system, a DNA chip, a microfluidic system, and an integrated small analysis system. It is an object of the present invention to provide a liquid concentration meter that can measure the efficiency efficiently, accurately, and stably.

  A fluid property measuring meter according to the present invention includes a chip in which a channel is formed by sandwiching a partition plate having a uniform thickness between two flat plates, at least one of which transmits light, and the channel of the chip. A light irradiating unit for irradiating light, a light receiving unit for receiving light transmitted through the flow channel, and a physical property of the fluid in the flow channel based on light intensity data received by the light receiving unit And a data processing unit.

  The fluid property measuring instrument of the present invention uses a chip composed of two flat plates and a partition plate sandwiched between them. The process of the fluid in the chip is performed at that point by making light incident on the flow path where the process proceeds, passing the fluid, receiving it, and measuring the intensity of the light. Know the situation. For this purpose, it is preferable that the distance that light passes through the flow path of the chip, that is, the depth dimension of the flow path is the same in any flow path. The Lambert-Beer law is established as the relationship between the attenuation of transmitted light of the fluid, the concentration or physical property of the fluid, and the light passage distance. If the light passage distance (cell length) is constant, the logarithmic value of the transmission intensity and the fluid There is a proportional relationship with the concentration (corresponding to the molar concentration of the following medium) or fluid physical properties (corresponding to the molar extinction coefficient of the following medium), and the physical properties related to the concentration or extinction coefficient of the fluid from the measurement of light transmission intensity It is because it can ask for.

Lambert-Beer's Law-log10 (I1 / I0) = a · b · c
I0: Incident intensity of light to the medium I1: Light transmission intensity from the medium a: Molar absorption coefficient of the medium b: Light passage distance of the medium c: Molar concentration of the medium

  However, in the conventional chip, as in Patent Document 1, a groove through which a fluid flows or a space in which the fluid flows is formed by an etching technique. Therefore, the variation in the etching process becomes the variation in the depth of the groove and the height direction of the space, and there is a problem that it is difficult to provide an accurate distance (cell length). Further, the etching process using a chemical solution such as hydrofluoric acid (HF) has a problem that the surface becomes rough and impairs light transmission.

  Therefore, a partition plate having a uniform thickness for determining the cell length is produced, and a chip is produced by sandwiching it between two planar plates like a sandwich. The partition plate is manufactured using an accurate parallel flat plate. Place the flow path and space in such a way that the planar shape forms a flow path shape by combining multiple parallel flat plates as partition plates, or provide through grooves and through holes in the partition plates To make. Therefore, it is guaranteed that the height (cell length) is the same everywhere on the chip. In this way, any part of the chip may be used, or only a part to be measured with light. However, optical properties of fluid properties, particularly fluid concentration, should be measured at a plurality of places to accurately and stably monitor the process in the chip. Can do.

As a method for irradiating and receiving light, there is first a method in which irradiation light is applied to a position of a flow path where light measurement is desired, and the light that has passed through the flow path is condensed on a light receiving element installed nearby. In this case, when measuring a plurality of locations, the functions of the irradiation unit and the light receiving unit as many as that number are required, and there is a disadvantage that the chip becomes complicated. Combining the irradiation unit functions together and installing only the light receiving unit individually can reduce the complexity.
Moreover, you may make it install an irradiation part and a light-receiving part in the place away from the chip | tip using the optical fiber. This method can also simplify the vicinity of the chip and reduce complexity.

  When an optical fiber is used, it is possible to measure at multiple measurement locations by installing the optical fiber at each measurement location. However, if measurement locations are provided at several tens or hundreds of locations in the chip, light irradiation is performed. It is not practical to install an optical fiber twice as large as the measurement location on the side and the light receiving side.

  Therefore, the fluid property measuring instrument of the present invention may be provided with a moving mechanism for relatively moving the light irradiation unit, the light receiving unit, and the chip. Thereby, a light irradiation part and a light-receiving part can be moved to arbitrary places, and it can measure efficiently. A plurality of points cannot be measured at the same time. However, if the latter is faster in terms of the fluid process time and the movement time of the light irradiating unit and the light receiving unit, a sufficient response can be made.

In the fluid property measuring instrument of the present invention having the above moving mechanism, the moving mechanism includes the light irradiation unit, the light receiving unit, and the chip in a plane parallel to the plane of the flat plate of the chip. Can be given as examples.
Further, the moving mechanism is an example in which the light irradiation unit, the light receiving unit, and the chip are relatively moved independently in two directions intersecting each other in a plane parallel to the plane of the plane plate. be able to.

In the fluid property measuring instrument of the present invention, the two flat plates of the chip both transmit light, and the light irradiating unit and the light receiving unit are arranged with the chip interposed therebetween. Can be mentioned.
Furthermore, an example in which the beam axis to the light receiving unit is perpendicular to the plane of the flat plate of the chip can be given.
An example in which one or both of the portion of the light irradiating portion that irradiates light to the chip and the portion of the light receiving portion that receives light from the chip includes an optical fiber.

Of the two flat plates of the chip, one transmits light, the other reflects light, and the light irradiation unit and the light receiving unit are on the same side with respect to the chip. It may be arranged at the position.
In this case, an example in which the portion of the light irradiating unit that irradiates light to the chip and the portion of the light receiving unit that receives light from the chip are formed by one optical system. Further, an example of the optical system includes an optical fiber.

In addition, the planar plate and the partition plate, which are constituent materials of the chip, are examples of glass materials, quartz, sapphire, polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), or a combination thereof. be able to.
In the fluid physical property measuring instrument of the present invention, examples of the physical property of the fluid to be measured include the absorbance or concentration of the fluid.

In the fluid physical property measuring instrument of the present invention, a chip in which a flow path is formed by sandwiching a partition plate having a uniform thickness between two flat plates, at least one of which transmits light, and a light in the flow path of the chip. A light irradiating unit for irradiating light, a light receiving unit for receiving light transmitted through the flow channel, and a data processing unit for calculating physical properties of the fluid in the flow channel based on light intensity data received by the light receiving unit And so on.
Since a chip having a channel formed therein is used by sandwiching a partition plate having a uniform thickness between two flat plates, the depth dimension of the channel in the chip, that is, the optical path length can be made uniform. In addition, the physical properties of the fluid in the flow path of the chip, such as absorbance and concentration, can be measured accurately and stably.

  In the fluid physical property measuring instrument of the present invention, if a moving mechanism for relatively moving the light irradiation unit and the light receiving unit and the chip is provided, the chip of the chip is formed by only one set of the light irradiation unit and the light receiving unit. It is possible to efficiently measure the physical properties of the fluid in the flow path, such as absorbance and concentration, at a plurality of locations.

In the fluid property measuring instrument of the present invention having a moving mechanism, the moving mechanism relatively moves the light irradiation unit, the light receiving unit, and the chip in a plane parallel to the plane of the plane plate of the chip. By doing so, stable measurement can be performed.
Further, the moving mechanism can move any one of the chips by moving the light irradiation unit, the light receiving unit and the chip relatively in two directions intersecting each other in a plane parallel to the plane of the plane plate. Measurement can also be performed at locations.

Also, the two flat plates of the chip both transmit light, and if the light irradiating part and the light receiving part are arranged with the chip in between, the light of the light irradiating part can be used without waste. Can be condensed.
Furthermore, if the beam axis to the light receiving portion is perpendicular to the plane of the plane plate of the chip, the transmission distance of light passing through the chip can be minimized. Thereby, the chip size including the light irradiation part and the light receiving part can be reduced.

  In addition, if one or both of the part that irradiates light to the chip of the light irradiation unit and the part that receives light from the chip of the light receiving unit include an optical fiber, the tip of the optical fiber and the necessary condensing optical system Therefore, it is possible to construct a miniaturized light irradiation part and light receiving part. The spectroscopic unit that irradiates the dispersed light and the sensor unit that converts the light intensity at the light receiving unit into an electrical signal may be installed at the end of the optical fiber opposite to the chip side. Can be realized.

  Also, one of the two flat plates of the chip is one that transmits light and the other is one that reflects light, and the light irradiating part and the light receiving part are arranged on the same side of the chip. As a result, both the light irradiation part and the light receiving part can be arranged on one side of the chip surface, and the chip size can be further reduced.

  Further, if the light irradiating part chip for irradiating the light and the light receiving part chip for receiving the light are formed by one optical system, the size can be further reduced. By utilizing the backward property of light, the irradiation optical system and the light receiving optical system can be made one. In order to separate the optical path between the light source portion for light irradiation and the light receiving element portion, it is necessary to use a translucent beam splitter or the like. When the optical system of these parts is equipped with an optical fiber, one optical fiber can be used as the optical fiber on the irradiation side and the optical fiber on the light receiving side, and the cost can be reduced by reducing the number of parts and the size of the apparatus can be reduced. .

In addition, the material of the flat plate and the partition plate of the chip can be selected from, for example, glass material, quartz, sapphire, polymethyl methacrylate (PMMA), and polydimethylsiloxane (PDMS).
If it is various glass materials, it is possible to appropriately select a material transparent to the light to be transmitted. In addition, the use of quartz among the glass materials is limited because the material is limited, so that even if it is not corroded by acid or alkali fluid, the material that dissolves is limited, It can be used in semiconductor processes that dislike metal contamination.
Further, although quartz is affected by hydrofluoric acid, it is preferable to use sapphire having corrosion resistance against the fluid containing hydrofluoric acid.
Acrylic resin represented by PMMA is highly transparent, thermoplastic, soluble in organic solvents such as acetone, and so on. Is possible. This is particularly effective when performing complicated processing in accordance with the flat plate or partition plate of the chip.
Since PDMS is colorless and transparent, rich in elasticity, and excellent in heat resistance and shape transferability, it is frequently used in microfluidic systems. Surface treatment according to the application is possible, such as making the resin surface hydrophobic or hydrophilic, and complex shape processing is also possible. Even when PDMS is used, mass production using a mold is possible, which is particularly effective when performing complicated processing according to a flat plate or a partition plate of a chip.

[Example 1]
FIG. 1 is a plan view for explaining a measurement unit according to an embodiment. FIG. 2 is a side view of the measurement unit. FIG. 3 is a diagram schematically showing the overall configuration of this embodiment.

As shown in FIG. 3, the fluid property measuring instrument of this embodiment is substantially composed of a spectroscopic unit 1, a measuring unit 2, and a data processing unit 3.
First, a specific configuration of the spectroscopic unit 1 will be described.

The spectroscopic unit 1 is provided with a tungsten lamp 4 as a light source, a convex lens 5, a rotating disk 7 including eight interference filters 6, a convex lens 8, a convex lens 11, and a light receiving element 12. . The light emitted from the tungsten lamp 4 is collected by the convex lens 5 and passes through the interference filter 6. Here, the interference filter 6 held by the rotating disk 7 separates the light into light having a predetermined wavelength within a range of 2000 to 2600 nm (nanometers).
The light split by the interference filter 6 is collected by the convex lens 8 and irradiated onto the incident end face 9 a of the light projecting side optical fiber 9. The light emitting side optical fiber 9 is connected to the measuring unit 2.

A measurement part is demonstrated with reference to FIG.1 and FIG.2.
Reference numeral 103 of the measurement unit 2 is a liquid preparation unit. The liquid adjustment unit 103 includes a chip 111 in which a flow path is formed, a metal frame 110 for supporting the chip 111, and a joint 112 for connecting the tubes 104, 105, and 108 to the chip 111. 113 and 114 are provided. The tubes 104, 105, and 108 are made of a resin such as PTFE (Poly Tetra Fluoro Ethylene) or PFA (tetrafluoroethylene-Perfluoro Alkyl vinyl ether copolymer). Detailed description of the liquid preparation unit 103 and the liquid feeding mechanism will be described later.

  The measurement unit 2 includes a moving mechanism for moving the measurement position, and can move the measurement position independently in the X-axis and Y-axis directions shown in FIG. Reference numeral 202 denotes a slider with a built-in stepping motor for moving the measurement position on the X axis, and reference numeral 203 denotes a slider with a built-in stepping motor for moving the measurement position on the Y axis.

  A U-shaped moving mechanism member 201 is provided with the liquid adjustment unit 103 interposed therebetween. The moving mechanism member 201 is provided with the emitting end face 9b of the light projecting side optical fiber 9, the incident end face 10a of the light receiving side optical fiber 10, and convex lenses 523 and 525 related thereto. The moving mechanism member 201 can be arbitrarily moved in the X and Y axes by the sliders 202 and 203 to change the irradiation position on the chip 111. The emission end surface 9 b of the light projecting side optical fiber 9 is connected to the emission side portion 522 of the moving mechanism member 201. A convex lens 523 is installed on the emission side portion 522, and the light from the emission end face 9b is condensed and irradiated onto the chip 111. The light passing therethrough is irradiated onto the convex lens 525 installed on the light receiving side portion 524 of the moving mechanism member 201, condensed, and condensed on the incident end face 10 a of the light receiving side optical fiber 10.

  The light projecting side optical fiber 9 and the convex lens 523 constitute a light irradiation part of the fluid concentration meter of the present invention. The light receiving side optical fiber 10 and the convex lens 525 constitute a light receiving portion of the fluid concentration meter of the present invention. The moving mechanism member 201 and the sliders 202 and 203 constitute a moving mechanism of the fluid concentration meter of the present invention.

  As shown in FIG. 3, the emission end face 10 b of the light receiving side optical fiber 10 is installed in the spectroscopic unit 1. The light incident on the incident end face 10 a of the light receiving side optical fiber 10 enters the convex lens 11 from the output end face 10 b of the light receiving side optical fiber 10, is condensed, and enters the light receiving element 12. The light receiving element 12 converts the incident light into a photocurrent corresponding to the intensity thereof. The data processing unit 3 calculates the physical property of the fluid at the measurement position based on the light intensity data received by the light receiving element 12.

  The rotating disk 7 holds the eight interference filters 6 at equal angular intervals in the circumferential direction, and is rotationally driven by the driving motor 13 at a predetermined rotational speed, for example, 1200 rpm (Revolutions Per Minute). Each interference filter 6 has a predetermined transmission wavelength different from each other in a range of 2000 to 2600 nm depending on the measurement target. Here, when the rotating disk 7 rotates, the interference filters 6 are sequentially inserted into the optical axes of the convex lenses 5 and 8. The light emitted from the tungsten lamp 4 is split by the interference filter 7 and then irradiated to a predetermined position of the chip 111 through the light projecting side optical fiber 9 and the convex lens 523. The light passing through the chip 111 is collected through the convex lens 525, enters the light receiving side optical fiber 10, passes through the convex lens 11, is collected, and enters the light receiving element 12. Thereby, an electrical signal corresponding to the absorbance of light of each wavelength is output from the light receiving element 12.

  By the way, a direct methanol fuel cell (DMFC) attracts attention as a small fuel cell 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. In this embodiment, a case where the aqueous methanol solution is adjusted to a predetermined concentration will be described.

FIG. 4 is a schematic diagram for explaining the configuration of the liquid feeding mechanism used in this embodiment.
A container 101 containing methanol having a concentration of 30% and a container 102 containing water are provided.
One end of a tube 104 is connected to a container 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 container 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. 5 is a diagram showing a plan view and a side view of the liquid preparation unit of the apparatus shown in FIG.
The preparation unit 103 connects the chip 111 having a flow channel formed therein by etching of glass, a metal frame 110 for supporting the chip 111, and the tubes 104, 105, and 108 to the chip 111. Joints 112, 113, 114. The chip 111 is a microfluidic device.

  The planar size of the chip 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 chip 111 disposed inside the frame part 110 is fixed by being pressed by joints 112, 113, and 114. The chip 111 has a tapered recess on the side surface at a position corresponding to the joints 112, 113, and 114, which is connected to the flow path inside the chip 111. By inserting the tips of the joints 112, 113, and 114 into the recesses on the side surfaces of the chip 111, the flow path is sealed to prevent liquid leakage.

FIG. 6 is a plan view showing a flow path pattern of the chip 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. 5 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 smaller than the other flow path portions of the chip 111.

  Sensor units 134 and 135 are provided in the flow paths 125 and 126 on the upstream side of the flow rate control unit 115. The sensor unit 134 is a small space used for monitoring the concentration of methanol. The sensor unit 135 is a small space used for monitoring the concentration of water, and monitors whether or not impurities such as methanol are contained.

  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. A sensor unit 136 is provided in the flow path 127 on the downstream side of the mixing unit 116. The sensor unit 136 is a small space used for measuring the methanol concentration after mixing.

  The sensor units 134, 135, and 136 are locations where light is irradiated by the measurement unit 2 described with reference to FIGS. 1 and 2. In the measurement unit 2, the sliders 202 and 203 are controlled to move the moving mechanism member 201 so that one of the sensor units 134, 135, and 136 of the chip 111 is irradiated with light. Further, by appropriately operating the sliders 202 and 203, the fluid concentration in the flow rate control unit 115, the mixing unit 116, and other flow paths can be measured.

FIG. 7 is a plan view showing the flow of liquid in the mixing unit 116 by 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. 6, since the mixing unit 116 is provided in two stages, the liquid is completely mixed by repeating the mixing pattern shown in FIG. 7 in two stages.

FIG. 8 shows a plan view and a side view for explaining the arrangement of the Peltier elements and the temperature measuring elements in the chip 111.
Two Peltier elements 118 and 119 are attached to the upper surface of the chip 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 chip 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 FIGS. 1, 2, and 5, illustration of the Peltier elements 118 and 119 and the temperature measuring elements 132 and 133 is omitted.

The chip 111 has a three-layer structure in which a glass partition plate having a uniform thickness in which a through groove for forming a flow path is formed is sandwiched between two glass flat plates.
FIG. 9 is a plan view showing a glass partition plate. FIG. 10 is a plan view showing a glass plate. FIG. 11 is a side view showing a glass partition plate and two glass plates before bonding. FIG. 12 is a side view showing a state where a chip is formed by joining a glass partition plate and two glass plates.

As shown in FIG. 9, the glass partition plate 137 is constituted by five glass plates indicated by reference numerals 137a to 137e. The glass plates 137a to 137e have a uniform thickness of 0.2 mm.
As shown in FIG. 10, the glass flat plates 138 and 139 are processed so that only the contact portion with the joint has a tapered shape. The glass flat plates 138 and 139 have a thickness of 1 mm.

The joint surfaces of the glass partition plate 137 and the glass flat plates 138 and 139 are polished flat. As shown in FIG. 11, a glass partition plate 137 is disposed between the glass flat plates 138 and 139. Specifically, the glass plates 137a to 137e constituting the glass partition plate 137 are arranged on the glass flat plate 139, and the glass flat plate 138 is arranged thereon. When heat is applied in a state where the glass partition plate 137 and the glass flat plates 138 and 139 are stacked and optical contact is made, the glass partition plate 137 and the glass flat plates 138 and 139 are bonded even without an adhesive. Then, a chip 111 is formed as shown in FIG.

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 chip 111, and are guided to the mixing unit 116 and mixed to become diluted methanol. The diluted methanol is guided from the tip 111 to the tube 108 and discharged through the pump 109.

  In FIG. 3, the interference filter 6 held on the rotating disk 7 includes a bandpass filter that passes 2260 nm having a difference between the near infrared spectra of methanol and water, and wavelengths in the vicinity of 2000 nm, 2100 nm, 2150 nm, 2200 nm, Eight pieces of 2300 nm, 2350 nm, and 2400 nm are attached. There is an absorption for the CH group of methanol at 2260 nm. The methanol concentration can be determined from Lambert-Beer law. The sensor unit 134 of the chip 111 is used for measurement for confirming that the methanol concentration is 30%. If the measurement result of the methanol concentration in the sensor unit 134 is not 30%, an alarm signal is issued because methanol having an incorrect concentration has been supplied. Similarly, the sensor unit 135 of the chip 111 is used for measurement for confirming that it is water. If the measurement result in the sensor unit 135 indicates that it is not water, a liquid that is not water is supplied, so that an alarm signal is issued.

  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.

The measurement position is mainly set in the sensor unit 136 of the chip 111, and the methanol concentration after mixing is measured 20 times per second, for example. Each time, the flow rate is controlled, and the methanol concentration after mixing is controlled to be constant almost continuously in real time. In addition, about once every 10 minutes, the sliders 202 and 203 are driven by the sensor units 134 and 135 to move the measurement position, thereby confirming 30% methanol and water.
Table 1 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 after mixing can be controlled to 4% by adjusting each temperature of the water side Peltier element 119 and the methanol side Peltier element 118.

  In this embodiment, 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 chip 111. The lower surface of the chip 111 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, so the heat dissipation speed is very fast compared to the daily level. Therefore, it is possible to sufficiently control the temperature only with a heating element using a heater.

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

[Example 2]
FIG. 13 is a side view for explaining a measurement unit according to another embodiment. FIG. 14 is a plan view of the measurement unit. FIG. 15 is a diagram schematically showing the overall configuration of this embodiment. The parts having the same functions as those in FIGS. 1 to 3 are denoted by the same reference numerals.

  In this embodiment, for the light irradiation optical system and the light receiving optical system of the measuring unit, the light projecting side optical fiber and the light receiving side optical fiber are made into one by utilizing the backward movement of light. As shown in FIG. 15, the basic structure of this embodiment is the same as that of Embodiment 1 described with reference to FIGS. In this embodiment, the light that has passed through the interference filter 6 in the spectroscopic unit 1 is collected by the convex lens 8, reflected by the mirror 601, collected by the convex lens 602, and irradiated onto the translucent beam splitter 603. The light reflected by the beam splitter 603 goes to the measurement unit 2 through the end face 604a of the optical fiber 604. The light transmitted through the beam splitter 603 is appropriately trapped and not used later. The light receiving side optical fiber 10 in FIG. 3 is used as the light projecting side optical fiber.

  As shown in FIG. 13, the light emitted from the end face 604 b of the optical fiber 604 passes through the convex lens 606 and is irradiated to the flow path of the chip 111. The surface 139a of the glass flat plate 139 of the chip 111 is a mirror surface, and the irradiated light is reflected by the surface 139a, travels backward, and returns from the end surface 604b to the optical fiber 604 again.

  Referring to FIG. 15, the light incident from the end surface 604b of the optical fiber 604 is guided to the spectroscopic unit 1 through the optical fiber 604, is emitted from the end surface 604a of the optical fiber 604, passes through the beam splitter 603, and passes through the convex lens 11. Is collected and enters the light receiving element 12.

  The measurement unit 2 will be described with reference to FIGS. 13 and 14. The liquid preparation unit 103 in the measurement unit 2 of this example has the same structure as the liquid preparation unit 103 of Example 1 except that the surface 139a of the glass flat plate 139 of the chip 111 is a mirror surface. In this embodiment, a moving mechanism member 605 is provided instead of the moving mechanism member 201 shown in FIGS. An end surface 604 b of an optical fiber 604 and a convex lens 605 are attached to the moving mechanism member 605. The moving mechanism member 605 can be arbitrarily moved in the X and Y axes by the sliders 202 and 203 to change the irradiation position on the chip 111.

  The method of making the surface 139a of the glass flat plate 139 of the chip 111 as a mirror surface will be described with reference also to FIG. 11. An aluminum vapor deposition film is formed on the surface 139a of the parallel plate 139 on the glass partition plate 137 side, for example, by metal vapor deposition. The method of doing is mentioned. Further, the parallel plate 139 itself may be made of a metal body, or the parallel plate 139 may be made of a material that greatly changes from the refractive index of the liquid to be measured. By doing so, the light reflectance is improved at the surface 139a of the flat plate 139, that is, at the boundary surface between the partition plate 137 and the flat plate 139.

[Example 3]
FIG. 16 is a diagram illustrating a plan view and a side view for explaining a measurement unit of still another embodiment. FIG. 17 is an enlarged view of the vicinity of the sensor unit 135 of FIG. FIG. 18 is a diagram schematically showing the overall configuration of this embodiment. The parts having the same functions as those in FIGS. 1 to 3 are denoted by the same reference numerals.

As shown in FIG. 18, the fluid property measuring instrument of this embodiment is substantially composed of a spectroscopic unit 1, a measuring unit 2, and a data processing unit 3.
First, a specific configuration of the spectroscopic unit 1 will be described.

The spectroscopic unit 1 is provided with a tungsten lamp 4 as a light source, a convex lens 5, a rotating disk 7 including four interference filters 6, and a convex lens 810. The light emitted from the tungsten lamp 4 is collected by the convex lens 5 and passes through the interference filter 6. Here, the four interference filters 6 held on the rotating disk 7 are a band-pass filter that passes light of 620 nm, a band-pass filter that passes light of 800 nm, and a band-pass filter that passes light of 1300 nm. And a band-pass filter that passes light of 1450 nm.
The light split by the interference filter 6 is converted into parallel light 814 by the convex lens 810 and irradiated to the measurement unit 2.

The measurement unit will be described with reference to FIGS. 16 and 17.
The chip 111 of the measurement unit 2 is basically the same as the chip described with reference to FIG. In the chip 111 of this embodiment, masks 801, 802, 803, condensing lenses 804, 805, 806, and light receiving elements 807, 808, 809 are added to the sensor portions 134, 135, 136. . Others are the same as the chip of FIG. The purpose of installing the masks 801, 802, and 803 is to prevent stray light from entering the light receiving elements 807, 808, and 809.

  The parallel light 814 emitted from the spectroscopic unit shown in FIG. 18 is uniformly applied to the entire surface of the chip 111 shown in FIG. The parallel light 814 is also applied to the masks 801, 802 and 803 of FIGS. 16 and 17 and passes through the through holes 811, 812 and 813 of the masks 801, 802 and 803. The light that has passed through the through holes 811, 812, and 813 passes through the flat plate 138, the partition plate 137, and the flat plate 139 of the chip 111. In the gap of the partition plate 137, the fluid to be measured exists. The light that has passed through the chip 111 is collected by the condenser lenses 804, 805, and 806 and enters the light receiving elements 807, 808, and 809, and converts the light intensity into an electrical signal. The electric signals from the light receiving elements 807, 808, and 809 are directed to the data processing unit 3.

  The collimated light 814 emitted from the spectroscopic unit 1 is irradiated with light having a center wavelength of 620 nm, 800 nm, 1300 nm, and 1450 nm of the interference filter 6 that is a bandpass filter in a time division manner by the rotation of the rotating disk 7. It will be. Which wavelength light is irradiated can be determined by a microcomputer in the data processing unit 3 based on a photo interrupter signal installed on the rotating disk 7. Based on the three electrical signals of the light receiving elements 807, 808, and 809 and the photo interrupter signal from the rotating disk 7, the data processing unit 3 includes sensor units 134, 808, 809 corresponding to the respective light receiving elements 807, 808, and 809. Absorbance data of each wavelength in the small spaces 135 and 136 can be calculated.

  The rotating disk 7 holds the four interference filters 6 at equal angular intervals in the circumferential direction, and is rotationally driven by the driving motor 13 at a predetermined rotational speed, for example, 1200 rpm. Each interference filter 6 is a band-pass filter that transmits light of 620 nm, 800 nm, 1300 nm, and 1450 nm, respectively. Here, when the rotating disk 7 rotates, the interference filters 6 are sequentially inserted into the optical axes of the convex lenses 5 and 810. Then, the light emitted from the tungsten lamp 4 is dispersed by the interference filter 6, and then converted into parallel light 814 by the convex lens 810, and is uniformly irradiated on the entire chip surface of the measurement unit 2.

  By the way, there is a demand for measurement of fluoride ions in wastewater by a factory wastewater test method for the purpose of environmental conservation. For this measurement, a lanthanum-alizarin complexone spectrophotometric method described in JIS K0102 34.1 is used. In this measurement method, it is known that the operation of mixing a reagent with a measurement target liquid and then performing spectroscopic measurement and quantifying it is complicated. An example in which this method is efficiently performed according to the present invention will be described.

  When performing this measurement according to the present invention, the liquid feeding mechanism described with reference to FIG. 4 can be used. Further, the chip 111 shown in FIG. 16 is arranged in the measurement unit in the same manner as the liquid preparation unit 103 shown in FIG.

  A lanthanum-alizarin complexone solution (described in JIS K0102 34.1 a) 6)) is provided with a container 101 and a container 102 containing a liquid to be measured. The liquid to be measured is a liquid after the distillation operation described in JISK0102.

  One end of a tube 104 is connected to the container 101. The other end of the tube 104 is connected to the liquid preparation unit 103. One end of a tube 105 is connected to the container 102. The other end of the tube 105 is connected to the liquid preparation unit 103. Also connected to the liquid preparation unit 103 is a tube 108 for flowing a mixture of the lanthanum-alizarin complexone solution and the measurement target solution from the tubes 104 and 105. Tube 108 is connected to pump 109. The operation of the pump 109 is controlled by the data processing unit 3. The pump 109 is moved to suck the liquid from the containers 101 and 102. The liquid enters the sensor units 134 and 135 which are small spaces in the chip 111. Thereafter, the liquid is also filled in the small space of the sensor unit 136. Whether or not the small spaces of the sensor units 134, 135, and 136 are filled with a predetermined liquid can be determined based on data from the respective light receiving elements 807, 808, and 809. After the sensor unit 136 is filled with the liquid, the pump 109 continues to be sucked for about 5 seconds, and then the pump 109 is stopped to stop the liquid flow.

  The sensor unit 134 is a small space used for monitoring the lanthanum-alizarin complexone solution. The sensor unit 135 is a small space used for monitoring the liquid to be measured, and monitors whether a liquid exists in each small space as predetermined. Since both methods are aqueous solutions, it is confirmed whether there is near-infrared absorption of OH groups of water and whether there is turbidity, bubbles, or impurities. Specifically, it can be confirmed by determining the absorbance of the characteristic absorption of the OH group at 1450 nm and the absorbance at 1300 nm with little OH group absorption in the vicinity thereof. When the measurement target liquid does not exist in the sensor units 134 and 135, the fluid in the sensor units 134 and 135 is air, and thus the light intensity at 1450 nm increases. In addition, when there are micro bubbles, turbidity, and impurities, light scattering and absorption increase, and the light intensity decreases at both 1450 nm and 1300 nm, which can be detected. When there is a liquid to be measured normally, 1300 nm and 1450 nm indicate predetermined absorbances, and the absorbance values in the normal state are stored in advance in the memory of the microcomputer in the data processing unit 3 and compared with them. Can be confirmed.

  The lanthanum-alizarin complexone solution and the measurement target solution are mixed in a predetermined volume. The method for controlling the mixing ratio is the same as in the first embodiment.

The mixed liquid is stopped by the sensor unit 136. Then, start measurement immediately. From the absorbance at 620 nm, the fluoride ion concentration can be determined. In order to stabilize the absorbance data, using a difference absorbance with respect to the absorbance at 800 nm, which is a wavelength not much related to the fluoride ion concentration, it is possible to remove errors such as light source fluctuation and sensitivity variation of the light receiving element.
Quantification of fluoride ion concentration is determined by measuring a plurality of standard solutions with known fluoride ion concentrations described in JIS K0102 34.1 a) 7) 8) in the same procedure, and the difference absorbance data between the concentration and 620 nm and 800 nm. Create a calibration curve between them. The data is stored in the microcomputer memory of the data processing unit 3. The calibration curve is compared with the difference absorbance data of 620 nm and 800 nm of the solution to be measured whose concentration is unknown to calculate the fluoride ion concentration.

  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 said Example, although the glass material is used as the partition plate 137 and glass plane plates 138 and 139 for forming the chip | tip 111, the partition plate and glass plane plate for forming a chip | tip are other materials, For example, it may be formed of quartz, sapphire, polymethyl methacrylate (PMMA), or polydimethylsiloxane (PDMS).

  In the above embodiment, the moving mechanism member 201 and the sliders 202 and 203 for moving the light irradiation unit and the light receiving unit with respect to the chip 111 are provided. However, the light irradiation unit and the light receiving unit fixed in position are provided. A moving mechanism for moving the chip may be provided.

  Moreover, in the said Example, although the Peltier device and a heater are used as a heat source which changes the temperature of a flow path, you may change the temperature of a flow path by irradiating light to a flow path. 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.

It is a top view for demonstrating the measurement part of one Example. It is a side view of the measurement part of the Example. It is a figure which shows schematically the whole structure of the Example. It is the schematic for demonstrating the structure of the liquid feeding mechanism used in the Example. It is a figure which shows the top view and side view of a liquid preparation part. It is a top view which shows the flow path pattern of the chip | tip of a liquid adjustment part. It is a top view which shows the flow of the liquid in the mixing part of a chip | tip by the arrow. It is a figure which shows the top view and side view for demonstrating arrangement | positioning of the Peltier device and temperature sensor in a chip | tip. It is a top view which shows the glass partition plate which comprises a part of chip | tip. It is a top view which shows the glass plate which comprises a part of chip | tip. It is a side view which shows the glass partition plate before joining, and two glass plates. It is a side view which shows the state which joined the glass partition plate and two glass plates, and formed the chip | tip. It is a side view for demonstrating the measurement part of another Example. It is a top view of the measurement part of the Example. It is a figure which shows schematically the whole structure of the Example. It is a figure which shows the top view and side view for demonstrating the measurement part of another Example. FIG. 17 is an enlarged view of the vicinity of a sensor unit 135 in FIG. 16. It is a figure which shows schematically the whole structure of the Example.

DESCRIPTION OF SYMBOLS 1 Spectrometer part 2 Measuring part 3 Data processing part 9,10,604 Optical fiber 103 Liquid preparation part 111 Chip | tip 134,135,136 Sensor part (flow path)
137 Partition plate 138, 139 Plane plate

Claims (13)

  A chip in which a flow path is formed by sandwiching a partition plate having a uniform thickness between two flat plates, at least one of which transmits light, and a light irradiation unit for irradiating light to the flow path of the chip A light receiving unit for receiving light transmitted through the flow path, and a data processing unit for calculating physical properties of the fluid in the flow path based on light intensity data received by the light receiving unit. Fluid property meter.   The fluid physical property meter according to claim 1, further comprising a moving mechanism for relatively moving the light irradiation unit, the light receiving unit, and the chip.   The fluid physical property meter according to claim 2, wherein the moving mechanism relatively moves the light irradiation unit, the light receiving unit, and the chip in a plane parallel to a plane of the flat plate of the chip. .   The said moving mechanism moves the said light irradiation part, the said light-receiving part, and the said chip | tip relatively independently in two directions which mutually cross | intersect in the plane parallel to the plane of the said plane plate. Fluid physical property meter. The two flat plates of the chip both transmit light,
The fluid physical property measuring instrument according to any one of claims 1 to 4, wherein the light irradiation unit and the light receiving unit are disposed with the chip interposed therebetween.   The fluid property measuring instrument according to claim 5, wherein a light beam axis to the light receiving unit is perpendicular to a plane of the flat plate of the chip.   7. The fluid according to claim 1, wherein one or both of a portion of the light irradiation unit that irradiates light to the chip and a portion of the light receiving unit that receives light from the chip include an optical fiber. Physical property meter. Of the two flat plates of the chip, one is one that transmits light and the other is one that reflects light,
The fluid physical property measuring instrument according to any one of claims 1 to 4, wherein the light irradiation unit and the light receiving unit are disposed at the same position with respect to the chip.   The fluid property measuring instrument according to claim 8, wherein a portion of the light irradiation unit that irradiates light to the chip and a portion of the light receiving unit that receives light from the chip are formed by one optical system.   The fluid property measuring instrument according to claim 9, wherein the optical system includes an optical fiber. The fluid physical property measuring instrument according to any one of claims 1 to 10, wherein a constituent material of the chip is any one of a glass material, quartz, sapphire, polymethylmethacrylate, polydimethylsiloxane, or a combination thereof.
  The fluid property meter according to any one of claims 1 to 11, wherein the physical property is an absorbance of the fluid.   The fluid physical property measuring instrument according to claim 1, wherein the physical property is a fluid concentration.

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