JP3739726B2 - Method and apparatus for controlling and measuring minute flow rate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for controlling and measuring a minute flow rate.
[0002]
[Prior art]
Traditionally, micro flow measurement has been performed by flowing the fluid as a steady flow in a thin pipe and counting its speed. However, in response to recent advances in the semiconductor and bio fields, there is a need for micro flow measurement. However, the situation is not always satisfactory.
[0003]
[Problems to be solved by the invention]
Therefore, the inventors of the present application flow a continuous phase and a dispersed phase on the micro flow side to be measured (hereinafter simply referred to as a dispersed phase) through orthogonal microchannels, and from the volume and number of microdroplets generated there. A method for accurately measuring minute flow rates was found.
[0004]
In view of the above situation, an object of the present invention is to provide a method and apparatus for controlling / measuring a micro flow rate capable of quickly and accurately measuring the flow rate of generated micro droplets.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides
[ 1 ] Micro droplets generated by sending out a dispersed phase which is a minute flow side to be measured so as to intersect the flow of the continuous phase at the confluence point of the continuous phase flowing in the microchannel formed on both sides In the control and measurement method of minute flow rate that measures
A method for controlling and measuring a micro flow rate, wherein the micro flow rate is measured based on the volume and generation rate of the micro droplets generated.
[0006]
[2] In the control and measurement method of the micro flow rate of [1] Symbol mounting, the volume and generation rate of microdroplets the generated, capable of changing by changing the height of the microchannels of the dispersed phase It is characterized by doing.
[0007]
[3] In the control and measurement method of the micro flow rate of [1] Symbol mounting, the volume and generation rate of microdroplets said generated to allow varied by varying the width of the micro-channels of the dispersed phase It is characterized by that.
[0008]
[4] In the control and measurement method of the micro flow rate of [1] Symbol mounting, the volume and generation rate of microdroplets said generated to allow varied by varying the height of the microchannels of the continuous phase It is characterized by that.
[0009]
[5] In the control and measurement method of the micro flow rate of [1] Symbol mounting, the volume and generation rate of microdroplets said generated to allow varied by varying the width of the micro-channels of the continuous phase It is characterized by that.
[0010]
[6] In the control and measurement method of the micro flow rate of [1] Symbol mounting, the volume and generation rate of microdroplets the generated, characterized in that to enable varied by varying the flow rate of the continuous phase And
[0011]
[ 7 ] At the confluence point of the continuous phase flowing in the microchannels formed on both sides, the micro droplets generated by sending out the dispersed phase on the micro flow side to be measured so as to intersect the flow of the continuous phase In the control / measurement device for a micro flow rate to be measured, a means for obtaining a volume of the generated micro droplet, a means for obtaining a generation rate of the generated micro droplet, and a volume of the generated micro droplet And a means for measuring a micro flow rate based on the generation rate.
[0012]
[8] In the control and measurement device for small flow rate of the [7] Symbol mounting, means for determining the production rate of the microdroplets, characterized by a device for measuring the number of counts per unit time of microdroplets And
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0014]
First, the production of microdroplets will be described.
[0015]
FIG. 1 is a plan view showing the path of a minute droplet according to the first embodiment of the present invention, and FIG. 2 is an explanatory diagram for controlling and measuring the minute flow rate. Here, FIG. 2A is a configuration diagram for controlling and measuring the minute flow rate, FIG. 2B is a cross-sectional view of a microchannel through which a continuous phase flows, and FIG. 2C is a cross-sectional view of a dispersed phase supply channel. is there.
[0016]
In these figures, 1 is a main body that forms a microdroplet path, 2 is a microchannel formed in the main body 1, through which a continuous phase flows, and 3 is a dispersed phase that is formed in a direction crossing the microchannel 2. Supply channel, 4 is a dispersed phase supply port, 5 is a continuous phase (for example, oil), 6 is a dispersed phase (for example, water), 7 is a microdroplet, 11 is a video camera, 12 is an interface (I / F), Reference numeral 13 denotes a PC (personal computer) with a built-in A / D converter.
[0017]
Therefore, the dispersed phase 6 is supplied to the continuous phase 5 flowing in the microchannel 2 in a direction crossing the flow of the continuous phase 5 as shown in FIG. By entering, micro droplets 7 are generated.
[0018]
For example, when the flow rate of the dispersed phase (water) 6 is fixed at 0.01 ml / h and the flow rate of the continuous phase (oil; edible sunflower oil) 5 is 12.0 ml / h, the microchannel 2 and the dispersed phase supply channel When the size of _{No. 3} is 200 μm in width W ₁ , 100 μm in W ₂ , and H ₁ and H ₂ in height are 100 μm, microdroplets 7 having a particle diameter of about 50 μm can be obtained.
[0019]
Next, a minute flow rate is measured from the minute droplets.
[0020]
Generally, micro flow rate = volume of micro droplets × generation rate, that is, Qd = Vms × Rms
Where Qd: micro flow rate (dispersed phase flow rate)
Vms: microdroplets one volume (πd ^3/6)
Rms: production rate, and the volume Vms of the fine droplets 7 is the flow rate Qd of the dispersed phase 6, the flow rate Qc of the continuous phase 5, and the dimension MC _D1 (height H ₁ × width W of the continuous phase supply microchannel 2 ₁ ) and the dimension MC _D2 (height H ₂ × width W ₂ ) of the dispersed phase supply channel 3.
[0021]
The volume Vms of the micro droplet 7 increases as the flow rate Qd of the dispersed phase 6 increases, and decreases as the flow rate Qd of the dispersed phase 6 decreases. Moreover, it becomes small, so that the flow rate Qc of the continuous phase 5 is large, and it becomes so large that the flow rate Qc of the continuous phase 5 is small. Furthermore, the volume Vms continuous phase feed microchannels 2 dimensions MC _D1, dispersed phase feed channel 3 dimensions MC _D2 is small enough microdroplets 7 becomes small.
[0022]
In this embodiment, as shown in FIG. 2, the generation rate of the microdroplets 7 is obtained by imaging the generated microdroplets 7 with a video camera 11 and A / D conversion via the interface (I / F) 12. The sample is taken into the PC 13 built in the container, and the liquid droplets flowing in the flow path are counted by image processing. Further, the volume of the fine droplet 7 is calculated from the count of the number of pixels by regarding the droplet as a sphere. That is, the minute flow rate can be calculated from the count calculated per unit time of the micro droplet 7 and the volume calculated from the count of the pixel number of the droplet.
[0023]
FIG. 3 is a block diagram showing the control and measurement of a minute flow rate according to the second embodiment of the present invention.
[0024]
In this figure, 16 is a counter electrode provided in the microchannel 2, 17 is a power source connected to the counter electrode 16, 18 is an amplifier that amplifies the output of the counter electrode 16, and 19 is connected to the amplifier 18. PC (personal computer).
[0025]
In this embodiment, when the generated micro droplet 7 passes between the counter electrodes 16, a change in potential difference generated at that time is detected and amplified by the amplifier 18, so that the output is taken into the PC 19, and the generation rate is changed. Measurement and calculation of the volume of the microdroplet are performed.
[0026]
FIG. 4 is a block diagram showing the control / measurement of the minute flow rate according to the third embodiment of the present invention.
[0027]
In this embodiment, the change in the electrostatic capacity when the generated microdroplets 7 pass is detected and the microdroplets 7 are counted. That is, a capacitance bridge 23 to which a high frequency power supply 24 and a PC (personal computer) 25 with a built-in A / D converter are connected is connected between the counter electrodes 21 and 22.
[0028]
FIG. 5 is a diagram showing a change in electrostatic capacitance due to the passage of the droplet, in which the horizontal axis indicates time (s) and the vertical axis indicates the capacitance (pF).
[0029]
As is apparent from this figure, a steep peak waveform is observed when the droplet passes. By detecting this waveform, fine droplets can be counted.
[0030]
FIG. 6 is a block diagram of a specific experimental apparatus.
[0031]
In this experiment, as the measurement conditions, the flow rate on the dispersed phase side was 0.1 ml / h, the flow rate on the continuous phase side was 5 ml / h, and liquid feeding was performed with a syringe pump. The microchannels on the continuous phase side and the dispersed phase side were both those having a cross-sectional width of 1 mm and a height of 1 mm.
[0032]
In this experimental apparatus, aluminum electrodes 31 and 32 are bonded to the microchannel 2 in which a continuous phase flows, and the capacitance between the electrodes 31 and 32 is measured by an LCZ meter (2330 manufactured by Keyence Corporation), and the data is GPIB. To a PC (personal computer) 34.
[0033]
As a result, the generation rate was 0.92 per second as an experimental value obtained from the peak count of capacitance, and 0.95 per second as counted visually.
[0034]
Further, since the particle diameter of the fine droplet 7 was 0.4 mm, when the flow rate on the dispersed phase side was calculated from this, both the change in capacitance and the flow rate obtained visually were 0.11 ml / h. The value was almost the same as the set value, and an extremely high correlation was obtained both experimentally and visually. Accumulation of measurement data seems to further improve accuracy.
[0035]
FIG. 7 is a diagram showing the relationship between the droplet diameter and the flow rate according to the present invention, and FIG. 8 is a diagram showing the relationship between the generation rate and the flow rate according to the present invention.
[0036]
In FIG. 7, the horizontal axis represents the average droplet diameter (μm), the vertical axis represents the calculated flow rate (ml / h), and the continuous phase flow rate is different (♦ is 10 ml / h (1), and ▲ is 10 ml). / H (2), ▪ indicates 30 ml / h).
[0037]
In FIG. 8, the horizontal axis indicates the droplet generation rate (1 / s), and the vertical axis indicates the calculated flow rate (ml / h), where the continuous phase flow rate is different (♦ is 10 ml / h (1), ▲ Indicates 10 ml / h (2), and ■ indicates 30 ml / h).
[0038]
As can be seen from these figures, according to the method and apparatus for controlling and measuring microdroplets according to the present invention, a micro flow rate can be accurately calculated.
[0039]
FIG. 9 is a diagram showing the relationship between the syringe pump set flow rate according to the present invention and the flow rate calculated from the droplet generation rate and volume. Here, the T-shaped flow path shown in FIG. 2 is used. The continuous phase channel width W ₁ is 500 μm, the dispersed phase channel width W ₂ is 100 μm, and the heights H ₁ and H ₂ are both 100 μm.
[0040]
In this figure, the flow rate of the continuous phase is different (♦ is 10 ml / h (1), ▲ is 10 ml / h (2), ■ is 30 ml / h,... Is a theoretical value).
[0041]
In addition, as a result of calculating the flow rate of water by “dispersion phase flow rate = droplet volume × generation rate”, it was found that the flow rate substantially coincided with the flow rate sent by the pump.
[0042]
Therefore, according to the present invention, it is possible to measure a minute flow rate by generating droplets in this way and using a counting method using changes in images, potential differences, and capacitance.
[0043]
FIG. 10 is a plan view showing the path of a microdroplet according to the fourth embodiment of the present invention, and FIG. 11 is an explanatory diagram of the method for manufacturing the microdroplet.
[0044]
In these figures, 121 is the main body of the microdroplet path, 122 is the first microchannel through which the first continuous phase flows, 123 is the second microchannel through which the second continuous phase flows, and 124 is the first microchannel. The continuous phase, 125 is the second continuous phase, 126 is the confluence point of the first continuous phase 124 and the second continuous phase 125, 127 is the dispersed phase supply channel, 128 is the dispersed phase, and 129 is the microdroplet. .
[0045]
Therefore, the disperse phase 128 is sent out at the junction 126 of the continuous phases 124 and 125 flowing in the first and second microchannels 122 and 123 so as to intersect the flow of the continuous phases 124 and 125 as shown in FIG. In this way, the micro droplet 129 can be generated.
[0046]
By applying the microdroplet control / measurement method and apparatus of the present invention described above to the microdroplet 129 generated in this way, a micro flow rate is generated based on the volume and generation rate of the microdroplet generated. Can be measured.
[0047]
In addition, this invention is not limited to the said Example, A various deformation | transformation is possible based on the meaning of this invention, and these are not excluded from the scope of the present invention.
[0048]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to easily and quickly measure a minute flow rate based on the volume and generation rate of the generated fine droplets.
[0049]
In addition, the volume and generation rate of the generated fine droplets can be controlled as appropriate, and even in this case, the flow rate can be accurately measured.
[0050]
Furthermore, in the semiconductor field and the gene manipulation field, the effect of the present invention is remarkable from the current situation that control and measurement of minute flow rates are becoming important technologies.
[Brief description of the drawings]
FIG. 1 is a plan view showing a path of a micro droplet according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram of control / measurement of a minute flow rate according to the first embodiment of the present invention.
FIG. 3 is a configuration diagram of control and measurement of a minute flow rate according to a second embodiment of the present invention.
FIG. 4 is a configuration diagram of control and measurement of a minute flow rate according to a third embodiment of the present invention.
FIG. 5 is a diagram showing a change in capacitance due to the passage of a droplet according to the present invention.
FIG. 6 is a configuration diagram of a specific experimental apparatus.
FIG. 7 is a diagram showing a relationship between a droplet diameter and a flow rate according to the present invention.
FIG. 8 is a diagram showing a relationship between a generation rate and a flow rate according to the present invention.
FIG. 9 is a diagram showing the relationship between the syringe pump set flow rate according to the present invention and the flow rate calculated from the droplet generation rate and volume.
FIG. 10 is a plan view showing a minute flow path according to a fourth embodiment of the present invention.
FIG. 11 is an explanatory diagram of a method for producing microdroplets showing a fourth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,121 The main body which forms the path | route of a micro droplet 2 The microchannel through which a continuous phase flows 3,127 Dispersed phase supply channel 4 Dispersed phase supply port 5 Continuous phase (for example, oil)
6 Dispersed phase (eg water)
7,129 Micro droplet 11 Video camera 12 Interface (I / F)
13, 19, 25, 34 PC (personal computer)
16, 21, 22 Counter electrode provided in flow path 17 Power source 18 Amplifier 23 Capacitance bridge 24 High frequency power source 31, 32 Aluminum electrode 33 LCZ meter 122 First microchannel 123 Second microchannel 124 First continuous Phase 125 Second continuous phase 126 Junction point of first continuous phase and second continuous phase 128 Dispersed phase

Claims (8)

At the confluence point of the continuous phase flowing in the microchannels formed on both sides, the micro droplet generated by sending out the dispersed phase which is the micro flow side to be measured so as to intersect the flow of the continuous phase is measured. In the control and measurement method of micro flow rate,
A method for controlling and measuring a micro flow rate, wherein the micro flow rate is measured based on the volume and generation rate of the micro droplets generated. Characterized in that in the control and measurement method of the minute flow rate according to claim 1 Symbol mounting, the volume and generation rate of microdroplets said generated to allow varied by varying the height of the microchannels of the dispersed phase A method for controlling and measuring minute flow rates. The control and measurement method of the minute flow rate according to claim 1 Symbol mounting, the volume and generation rate of microdroplets the produced, and characterized by enabling varied by varying the width of the micro-channels of the dispersed phase Control and measurement method for minute flow rate. The control and measurement method of the minute flow rate according to claim 1 Symbol mounting, the volume and generation rate of microdroplets said generated, and characterized in that the changeable by height variation of the micro-channels of the continuous phase Control and measurement method for minute flow rate. The control and measurement method of the minute flow rate according to claim 1 Symbol mounting, the volume and generation rate of microdroplets the produced, and characterized by enabling varied by varying the width of the micro-channels of the continuous phase Control and measurement method for minute flow rate. The control and measurement method of the minute flow rate according to claim 1 Symbol placement, minute flow rate of the volume and generation rate of microdroplets the generated, characterized by enabling varied by varying the flow rate of the continuous phase Control / measurement method. The micro-droplet generated by sending the dispersed phase on the micro-flow side to be measured so as to intersect the continuous-phase flow at the confluence point of the continuous phase flowing in the microchannel formed on both sides. In flow control / measurement equipment,
(A) means for determining the volume of the generated microdroplets;
(B) means for determining a generation rate of the generated microdroplets;
(C) A device for controlling and measuring a micro flow rate, characterized by comprising means for measuring the micro flow rate based on the volume and generation rate of the generated micro droplets. The control and measurement system of micro flow rate of claims 7 Symbol mounting, means for determining the production rate of the microdroplets, minute flow rate, which is a device for measuring the number of counts per unit time of microdroplets Control / measurement equipment.

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