JP2015211931A - Method and apparatus for producing microdroplet using microfluidic chip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and efficiently produce microdroplets at a low cost.SOLUTION: A microfluidic chip is prepared (S1) which comprises a chip body formed of a synthetic resin capable of occluding gas and a substrate bonded to the chip body in a state of being airtightly sealed, in which the chip body is provided with first to third liquid reservoirs, and first to third microchannels respectively extending from the first to third liquid reservoirs and connected at one point. After the third liquid reservoir is covered with a lid, the microfluidic chip is deaerated (S2). The deaerated microfluidic chip is placed under the atmospheric pressure, and then a liquid serving as a continuous phase is poured into the first reservoir and a liquid serving as a dispersion phase is poured into the second liquid reservoir (S3). The liquid serving as a continuous phase and the liquid serving as a dispersion phase are made to flow to the third liquid reservoir from the first and second liquid reservoirs respectively to form an emulsion in the third microchannel to collect the emulsion in the third liquid reservoir (S4, S5).

Description

  The present invention relates to a method for producing microdroplets using a microfluidic chip and a microdroplet producing apparatus using a microfluidic chip.

  With the development of nanotechnology using microfluidics in recent years, microdroplets (emulsions) are widely used as materials for forming micro reaction containers and microcapsules in fields such as biotechnology and drug manufacturing. Yes.

The micro droplets are manufactured using, for example, a microfluidic chip (see, for example, Patent Documents 1 and 2 and Non-Patent Document 1).
According to this method for producing microdroplets, the microfluidic chip usually has a plate shape made of glass, silicon, or the like, and includes a first liquid reservoir for storing a liquid serving as a continuous phase, and a dispersed phase. At least one second liquid reservoir for storing a liquid to be stored and a third liquid reservoir for storing microdroplets (emulsions), and the first to third liquid reservoirs on the surface or inside thereof, respectively. The first to third microchannels are connected to each other at a single point extending from the bottom.

  In addition, according to this method for producing microdroplets, a syringe pump and other micropumps are prepared, and by this micropump, a liquid that is a continuous phase is sent to the first liquid reservoir of the microfluidic chip, A liquid serving as a dispersed phase is sent to the second liquid reservoir.

  By the liquid feeding by the micropump, the liquid that becomes the continuous phase and the liquid that becomes the dispersed phase flow from the first and second liquid reservoirs toward the third liquid reservoir through the first and second microchannels, respectively. At that time, an emulsion is formed in the third microchannel, and in the third liquid reservoir, the fine liquid droplets serving as the dispersed phase are collected together with the liquid serving as the continuous phase.

  However, according to this conventional method, it is necessary to use an expensive liquid feeding means such as a syringe pump for feeding each of the liquid that becomes the continuous phase and the liquid that becomes the dispersed phase. It is difficult to adjust the flow rate of the liquid, and a considerable amount of dead volume of the liquid that becomes the dispersed phase is generated. Therefore, there is a problem that the production efficiency of the microdroplet is low and the production cost is high.

JP 2004-358386 A International Publication No. 2012/008497 Pamphlet

Deniz Pekin et al. `` Quantitative and sensitive detection of rare mutations using droplet-based microfluidics '' Lab Chip, The Royal Society of Chemistry, 2011, Vol. 11, P.2156-2166

  Accordingly, an object of the present invention is to enable easy and efficient production of microdroplets at low cost.

  In order to solve the above-mentioned problems, the present invention is a method for producing microdroplets using a microfluidic chip, (1) a plate-shaped chip body formed from a synthetic resin capable of occluding gas, A synthetic resin of the same type as the synthetic resin or another type of synthetic resin or glass, and a substrate bonded in an airtight manner to one surface of the chip body, First, a microfluidic chip provided with first to third liquid reservoirs and first to third microchannels connected to each other at one point from the bottom of each of the first to third liquid reservoirs is prepared. 2) After covering the third reservoir of the microfluidic chip, the microfluidic chip was degassed by placing the microfluidic chip under reduced pressure for a predetermined time, and (3) the degassed Front of microfluidic chip The third liquid reservoir is placed under atmospheric pressure with the lid on, and a liquid that is a continuous phase is injected into the first liquid reservoir, while a liquid that is a dispersed phase is injected into the second liquid reservoir. Using the gas occlusion action of the synthetic resin, the liquid that becomes the continuous phase and the liquid that becomes the dispersed phase from the first and second liquid reservoirs through the first and second microchannels, respectively. Flow toward the third liquid reservoir, form an emulsion in the third microchannel, and in the third liquid reservoir, the liquid droplets that become the dispersed phase together with the liquid that becomes the continuous phase The method is characterized by collecting.

  In the above configuration, preferably, each of the first to third microchannels tapers from a point before the connecting point to the connecting point. In this case, each of the first to third microchannels has the same depth over its entire length, and a wide portion extending from the liquid reservoir concerned to the point before the connection point, and the wide It is preferable that the taper portion has a taper portion that is gradually narrowed and connected to the tip of this portion, and a narrow portion that extends from the tip of the taper portion to the connecting point.

  In the above configuration, preferably, the chip body of the microfluidic chip is provided with each one of the first to third liquid reservoirs, and the first to third microchannels are the first and third liquid channels. One of the second microchannels and the third microchannel are aligned, and the other of the first and second microchannels is the third macrochannel and the first and second microchannels. The microfluidic chips are connected to each other in a T shape in an arrangement perpendicular to one of the two microchannels. Alternatively, each of the microfluidic chip has a first to third chip body. A pair of the first microchannels extending from the first reservoir, the first microchannel set, and the second and third microchannel sets. Are connected to each other in a cross shape at the one point, or The chip body of the microfluidic chip is provided with the two first liquid reservoirs and the second and third liquid reservoirs, each of which has two lines extending from the two first liquid reservoirs. The set of the second microchannels and the set of the second and third channels are connected to each other in a cross shape at the one point.

Preferably, the volume of the third liquid reservoir is larger than the total volume of the first and second liquid reservoirs.
The synthetic resin capable of occluding the gas is preferably polydimethylsiloxane (PDMS), and the lid for the third liquid reservoir is preferably a glass plate.

  In order to solve the above problems, the present invention also includes a chamber, an exhaust pipe having one end connected to the chamber, a pump connected to the other end of the exhaust pipe, and exhausting from the chamber, A first valve provided in the middle of the exhaust pipe, a leak pipe branched and connected to the upstream side of the first valve in the exhaust pipe, a second valve provided in the middle of the leak pipe, A microfluidic chip disposed in the chamber, the microfluidic chip comprising a plate-like chip body formed of a synthetic resin capable of occluding gas, and a synthetic resin of the same type as the synthetic resin or another A substrate formed of a synthetic resin or glass of the above type and bonded in a state of being hermetically sealed to one surface of the chip body, the chip body includes first to third liquid reservoirs, Before each A first to a third microchannel connected to each other at a single point from the first to the third reservoir, and a lid capable of sealing the third reservoir of the microfluidic chip; A first liquid supply source arranged outside the chamber for supplying a liquid as a continuous phase, and a second liquid supply source arranged outside the chamber for supplying a liquid as a dispersed phase. A first liquid supply pipe for supplying the liquid as the continuous phase from the first liquid supply source to the first liquid reservoir of the microfluidic chip; and the micro from the second liquid supply source. A second liquid supply pipe for supplying the liquid serving as the dispersed phase to the second liquid reservoir of the fluid chip, and a microdroplet using a microfluidic chip This constitutes a manufacturing apparatus.

  According to the present invention, since the chip body of the microfluidic chip is formed of a synthetic resin capable of occluding gas, after the third liquid reservoir of the chip body is covered, the microfluidic chip is placed under reduced pressure. When the degassed and degassed microfluidic chip is placed under atmospheric pressure with the third liquid reservoir covered, the chip body begins to occlude air again, so that the third liquid reservoir remains in the third liquid reservoir for a certain period of time. Maintained under reduced pressure.

  At this time, when the liquid that becomes the continuous phase and the liquid that becomes the dispersed phase are injected into the first and second liquid reservoirs of the chip body, respectively, these liquids autonomously become the first and second microchannels, Furthermore, it flows toward the third liquid reservoir through the third microchannel. In the meantime, an emulsion is formed in the third microchannel, and the liquid droplets that become the dispersed phase are automatically collected together with the liquid that becomes the continuous phase in the third liquid reservoir.

Thus, according to the present invention, there is provided a micropump such as a syringe pump for feeding the liquid that becomes the continuous phase and the liquid that becomes the dispersed phase from the first and second liquid reservoirs toward the third liquid reservoir, respectively. It becomes unnecessary. In addition, if a liquid that is a continuous phase and a liquid that is a dispersed phase are injected into the first and second liquid reservoirs, the respective liquids autonomously flow toward the third liquid reservoir. There is no need to control the liquid flow rate.
Furthermore, by injecting into the second liquid reservoir the required amount of liquid that becomes the dispersed phase calculated based on the volume of the third liquid reservoir, the dead volume of the liquid that becomes the dispersed phase does not occur.
As a result, the production of microdroplets can be performed easily and efficiently at a low cost.

FIG. 3 is a flow diagram of a method for producing microdroplets using a microfluidic chip according to the present invention. It is a perspective view which shows an example of the microfluidic chip | tip used in the method by this invention. It is a figure which shows arrangement | positioning of the liquid reservoir and microchannel of the microfluidic chip of FIG. 2, (A) is a top view, (B) is the figure which expanded a part of (A). It is a schematic diagram explaining the process after step S2 of FIG. 1, and is a part from the first liquid reservoir of the microfluidic chip to the third liquid reservoir through the first microchannel and the third microchannel. FIG. It is the photograph which reflected the state of the microfluidic chip before deaeration in experiment. In an experiment, it is the photograph which reflected the state which inject | pours a liquid into the 1st and 2nd liquid reservoir of a microfluidic chip after deaeration. It is the photograph which reflected the state in which the emulsion formed in the 3rd microchannel was collected by the 3rd liquid reservoir in experiment. It is the graph which showed the time change of the production speed and the total number of production | generation of a microdroplet at the time of using the microfluidic chip | tip after deaeration for 1 hour. It is the graph which showed the time change of the production | generation speed | rate and the total number of production | generation of a microdroplet at the time of using the microfluidic chip after deaeration for 1.5 hours. It is the graph which showed the time change of the production speed and the total number of production | generation of a microdroplet at the time of using the microfluidic chip after deaeration all day and night. It is a sectional side view which shows schematic structure of an example of the micro droplet manufacturing apparatus by this invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a flow diagram of a method for producing microdroplets using a microfluidic chip according to the present invention.
Referring to FIG. 1, according to the present invention, a microfluidic chip is first prepared (S1 in FIG. 1).

FIG. 2 is a perspective view showing an example of a microfluidic chip used in the method for producing microdroplets according to the present invention, and FIG. 3 shows the arrangement of the liquid reservoirs and microchannels of the microfluidic chip of FIG. (A) is a plan view, and (B) is an enlarged view of part of (A).
Referring to FIGS. 2 and 3, the microfluidic chip has a plate-shaped chip body 1 having a constant thickness formed from a synthetic resin capable of occluding gas. In this embodiment, polydimethylsiloxane (PDMS) is used as a synthetic resin for forming the chip body 1.

  The chip body 1 is provided with three cylindrical holes 2 to 4 penetrating from the one surface side to the other surface side. In this case, the diameters of the three holes 2 to 4 are such that the sum of the volume of the first hole 2 and the volume of the second hole 3 is smaller than the volume of the third hole 4. Is set to

  Further, on one surface of the chip body 1, a first fine groove 5 connected to the opening edge of the first hole 2, a second fine groove 6 connected to the opening edge of the second hole 3, and A third fine groove 7 connected to the opening edge of the third hole 4 is provided, and the first to third grooves 5 to 7 are connected to each other at one point P.

The first to third grooves 5 to 7 are each tapered from the front of the connection point P toward the connection point P.
In this embodiment, each of the first to third grooves 5 to 7 has the same depth over its entire length, and the wide portions 5a to 5a extending from the related holes 2 to 4 and before the connection point P. 7a, tapered portions 5b to 7b that are gradually narrowed and connected to the tips of the wide portions 5a to 7a, and narrow portions 5c to 7c that extend from the tips of the tapered portions 5b to 7b to the connecting point P. .

  Further, at the connection point P, the first to third grooves 5 to 7 are one of the first and second grooves 5 and 6 (in this embodiment, the second groove 6) and the third groove. 7 is a straight line, and the other of the first and second grooves 5, 6 (in this embodiment, the first groove 5) is one of the first and second grooves 5, 6 (this implementation). In the example, the second groove 6) and the third groove 7 are orthogonally connected to each other and are connected in a T shape.

And the board | substrate 8 formed from glass is joined to the surface in which the 1st-3rd groove | channels 5-7 of the chip | tip body 1 were provided in the state airtightly sealed. In this case, due to the strong self-adsorption property of the PDMS that forms the chip body 1, the chip body 1 and the substrate 8 can be joined in an airtight sealed state simply by bringing them into contact with each other.
In addition, the forming material of the board | substrate 8 is not limited to glass, The board | substrate 8 may be formed from the synthetic resin of the same kind as the synthetic resin which forms the chip body 1, or another kind of synthetic resin.

By joining the chip body 1 and the substrate 8, one end openings of the first to third holes 2 to 4 of the chip body 1 are sealed, and the first to third liquid reservoirs m ₁ of the microfluidic chip are sealed. ~m ₃ is formed, also, of each of the first to third groove 5-7 of the chip body 1, an opening portion formed on the surface of the chip body 1 is being closed sealed, first microfluidic chip to third microchannel _n 1 ~n ₃ is formed.
The microfluidic chip is used in an arrangement with the substrate 8 down.

The configuration of the microfluidic chip is not limited to that described above, and various modifications are possible.
For example, in the above embodiment, is provided with the first to third liquid reservoir _m 1 ~m ₃ only one pair to the microfluidic chip, the first to third liquid reservoir _m 1 ~m microfluidic chip _A plurality of sets of ₃ may be provided.
In the above-described embodiment, the first to third microchannels n _{1 to} n ₃ are connected to each other in a T shape, but the first microchannel n extending from the first liquid reservoir m _{1 is used. A} pair of ₁ may be provided, and at the connection point P, the set of the first microchannel n _{1 and} the set of the second and third microchannels n ₂ and n ₃ may be connected to each other in a cross shape.

Further, for example, the chip body 1 is provided with two first liquid reservoirs m ₁ and one second and third liquid reservoirs m ₂ and m ₃ , respectively, and extends from the two first liquid reservoirs. A set of two first microchannels n _{1 and} a set of second and third channels n ₂ and n ₃ may be connected to each other in a cross shape at one point.

According to the present invention, then, after the lid is placed over the third liquid reservoir m _3, the microfluidic chip is placed under reduced pressure, is degassed (S2 in FIG. 1). In this embodiment, the lid is made of a glass plate. In this case, since the PDMS to form a chip body 1 has a strong self-adsorptive, simply by placing a glass plate so as to cover the opening of the third liquid reservoir m ₃ from the top of the chip body 1, a glass The plate and the chip body 1 can be adsorbed and sealed in a state where the upper end opening of the _third liquid reservoir m3 is hermetically sealed.

  The pressure value at the time of degassing the microfluidic chip and the time for which the microfluidic chip is kept under reduced pressure are not particularly limited, and these parameters are autonomous microfluids by the air re-occlusion action of the chip body 1 described later. It is set so that the production of the drops is performed appropriately.

Next, the degassed microfluidic chip is placed under atmospheric pressure with the _third liquid reservoir m ₃ covered with a lid, and a liquid that is a continuous phase is injected into the first liquid reservoir m _1. Then, a liquid to be a dispersed phase is injected into the _second liquid reservoir m ₂ (S3 in FIG. 1).

In this case, when the degassed microfluidic chip is placed under the atmospheric pressure with the third liquid reservoir m ₃ covered with the lid, the chip body 1 begins to occlude air again, thereby the reservoir m ₃ is maintained constant time reduced pressure.
At this time, when a liquid that is a continuous phase and a liquid that is a dispersed phase are injected into the first and second liquid reservoirs m ₁ and m ₂ of the chip body 1, these liquids are autonomously first and a second microchannel _n 1, _{n 2,} flows toward the further third microchannel _{n 3} through the third liquid reservoir _{m 3} of. In the meantime, an emulsion is formed in the third microchannel n ₃ , and the liquid microdroplets that become the dispersed phase are automatically collected in the third liquid reservoir m ₃ together with the liquid that becomes the continuous phase ( (S4, S5 in FIG. 1)

Hereinafter, the process after step S2 in FIG. 1 will be described in more detail.
Figure 4 is a schematic view for explaining the step S2 after the process of FIG. 1, the first reservoir m ₁ of the microfluidic chip, the first microchannel n ₁ and the third microchannel n ₃ FIG. 5 is a diagram showing a side cross section of a portion that reaches the third liquid reservoir m ₃ through the above.
4A shows a state where the microfluidic chip is placed under reduced pressure, FIG. 4B shows a state where the degassed microfluidic chip is placed under atmospheric pressure, and FIG. FIG. 4D shows a state in which a liquid that becomes a continuous phase is injected into the liquid reservoir m ₁ , and FIG. 4D shows a liquid in which an emulsion is formed in the third microchannel n ₃ and becomes a dispersed phase in the _third liquid reservoir m _3. This shows a state in which the micro droplets are collected.

As shown in FIG. 4A, when the micro liquid chip is placed under reduced pressure, the air stored in the chip body 1 is released to the outside, and at the same time, the first liquid reservoir m ₁ , the first micro flow path n ₁ , air is also released to the outside from the inside of each of the third microchannel n ₃ and the third liquid reservoir m ₃ .

Then, as shown in FIG. 4B, when a degassed microfluidic chip lid 9 is placed under the atmospheric pressure while placed over the third liquid reservoir m _3, the first third of reservoir m ₁ The air flows toward the liquid reservoir m ₃ , and this air is re-occluded by the chip body 1, and the air is re-occluded by the first and third liquid reservoirs m ₁ and m ₃ and the micro flow channels n ₁ and n 3. ₃ is absorbed from the wall surface.
At this time, as shown in FIG. 4C, the liquid u as a continuous phase in the first liquid reservoir m ₁ is injected, the liquid u autonomously, the first and third micro flow in a reduced pressure state It flows toward the third liquid reservoir m ₃ through the paths n ₁ and n ₃ .

During this time, as shown in FIG. 4D, the emulsion w is formed in the third microchannel n _3, the third liquid reservoir m _3, the liquid fine droplets of liquid as a disperse phase is a continuous phase Collected with u. This emulsion generation process continues while the space left in the _third liquid reservoir m3 is maintained in a reduced pressure state.

Thus, according to the present invention, the liquid for the continuous phase and the liquid for the dispersed phase are fed from the first and second liquid reservoirs m ₁ and m ₂ to the third liquid reservoir m ₃ , respectively. A micro pump such as a syringe pump becomes unnecessary. In addition, if a liquid that is a continuous phase and a liquid that is a dispersed phase are injected into the first and second liquid reservoirs m ₁ and m ₂ , respectively, they flow autonomously toward the third liquid reservoir m ₃ . There is no need to control the flow rate of each liquid.
It was also calculated based on the third volume of the liquid reservoir m _3, the required amount of liquid as a disperse phase by injecting the second in liquid reservoir m _2, even dead volume of liquid as a disperse phase generator do not do.
As a result, the production of microdroplets can be performed easily and efficiently at low cost.

Next, in order to confirm the effect of the present invention, an experiment was conducted and the result was evaluated.
In the experiment, a microfluidic chip having the same configuration as that shown in FIGS. 2 and 3 was prepared. The dimensions of each part of the microfluidic chip are as follows.
・ Chip body 1: 50 mm long x 70 mm wide x 4 mm thick
-Substrate 8: 52 mm long x 76 mm wide x 1 mm thick
-Diameter of the first liquid reservoir m ₁ : d ₁ = 6 mm
- a second diameter of the liquid reservoir _{m 2:} d 2 = 4 mm
- third of the diameter of the reservoir _{m 3:} d ₃ = 8mm
The distance between the center of the first liquid reservoir m ₁ and the point P in the lateral direction of the chip body: L ₁ = 7 mm
The distance between the center of the second liquid reservoir m ₂ and the point P in the lateral direction of the chip body: L ₂ = 7 mm
The distance L ₃ = 7.5 mm between the center of the second liquid reservoir m ₂ (first liquid reservoir m ₁ ) and the point P in the longitudinal direction of the chip body
-Distance L ₄ + L ₅ = 7.5 mm between the center of the third liquid reservoir m ₃ and the point P in the longitudinal direction of the chip body
- of the chip body longitudinal direction, the distance between the third connection point between the center and the third microchannel _{n 3} of the reservoir _{m 3 of:} L 5 = 1 mm
-Depth of the first to third microchannels n _{1 to} n ₃ : 50 μm
- first to third microchannel _n 1 ~n ₃ of the wide portion 5a, 6a, 7a of the respective _widths: d 4 = 250 [mu] m
- length of each of the first to third microchannel _n 1 ~n ₃ of the tapered portion _{5b, 6b, 7b: d 5} = 300μm
- first to third microchannel _n 1 ~n _third narrow portion 5c, 6c, 7c of the respective _widths: d 6 = 50 [mu] m
The length d ₇ of the narrow portion 5c of the first microchannel n1 = 0.2 mm
The length d ₈ of the narrow portion 6c of the second microchannel n2 = 0.2 mm
The length d ₉ = 2 mm of the narrow part 7c of the third microchannel n3
In this experiment, the microfluidic chip includes four sets of the _first to third liquid reservoirs m _{1 to} m ₃ , but only one of them is used.

As shown in FIG. 5, the microfluidic chip is housed in a pump built-in vacuum desiccator with the third liquid reservoir m ₃ covered with a cover glass (lid), and the pump is operated to decompress the desiccator. Then, when the inside of the desiccator reached a predetermined pressure value, the pump was stopped and the inside of the desiccator was maintained in a reduced pressure state for 1 hour.

Thereafter, as soon as the microfluidic chip is taken out from the desiccator and placed under atmospheric pressure with the cover glass covered on the third liquid reservoir m ₃ , the microfluidic chip is placed in the first liquid reservoir m ₁ as shown in FIG. 60 μL of mineral oil solution containing 2% (vol / vol) ABIL EM90 and 0.05% (vol / vol) Triton X-100 (both are surfactants) was injected as a liquid to be a continuous phase. 20 μL of the PCR reaction solution (polymerase chain reaction solution) was injected into the second reservoir m ₂ .

After about 3.5 minutes, an emulsion is formed in the third micro flow path n ₃ , and as shown in FIG. 7, microdroplets of the PCR reaction liquid are added to the mineral oil liquid in the _third liquid reservoir m _3. It was collected with.
At this time, the time change of the production speed of the micro droplets of PCR was measured with reference to the time point when the mineral oil solution and the PCR reaction solution crossed at the point P. Furthermore, the time change of the total number of generated microdroplets was calculated by integrating the obtained generation speed.
The results are shown in the graph of FIG. In the graph of FIG. 8, curve X represents the total number of microdroplets generated, and curve Y represents the microdroplet generation speed.

Using the same microfluidic chip, with each degassing time of 1.5 hours and day and night, in each case, as before, measure the time variation of the microdroplet production rate and produce the microdroplet The total time change was calculated.
The results when the deaeration time is 1.5 hours are shown in the graph of FIG. 9, and the results when the deaeration time is all day and night are shown in the graph of FIG.

From the graphs of FIGS. 8 to 10, when the pressure during decompression is the same, the longer the deaeration time, the higher the generation rate of the microdroplets, and it is possible to generate a large number of microdroplets in a shorter time. all right.
In each of the above three different experiments, the time change of the particle size of the generated microdroplet was measured. In any case, the particle size of the microdroplet was almost constant regardless of time (about 90 μm). )Met.

FIG. 11 is a side sectional view showing a schematic configuration of an example of a micro droplet manufacturing apparatus according to the present invention.
As shown in FIG. 11, the micro droplet manufacturing apparatus of the present invention exhausts from the chamber 10, the exhaust pipe 11 having one end connected to the chamber 10, and the other end of the exhaust pipe 11. Pump 12, a first valve 13 provided in the middle of the exhaust pipe 11, a leak pipe 14 branched and connected upstream of the first valve 13 in the exhaust pipe 11, and in the middle of the leak pipe 14 A second valve 15 is provided.

  In this embodiment, the chamber 10 has a cylindrical shape with both ends closed, and is separable into a chamber main body 10a and an upper lid 10b. In this case, when the upper end opening of the chamber body 10a is closed by the upper lid 10b, the annular lower end surface of the upper lid 10b comes into contact with the annular upper end surface of the chamber body 10a via the O-ring 10c.

The microdroplet production apparatus also includes a microfluidic chip 16 disposed in the chamber 10.
The microfluidic chip 16 has the same configuration as that shown in FIGS. 2 and 3 except that the microfluidic chip 16 has a plurality of sets of the _first to third liquid reservoirs m _{1 to} m ₃ . Yes.
Although not shown, the micro droplet manufacturing apparatus includes a lid that can seal the third liquid reservoir m ₃ of the microfluidic chip 16.

Further, the microdroplet manufacturing apparatus includes a first liquid supply source 17 that supplies liquid that becomes a continuous phase, which is arranged outside the chamber 10, and a liquid which becomes a dispersed phase, which is arranged outside the chamber 10. A second liquid supply source 18 for supplying, and a first liquid supply pipe 19 for supplying a liquid as a continuous phase from the first liquid supply source 17 to the first liquid reservoir m ₁ of the microfluidic chip 16. , A second liquid supply pipe 20 is provided for supplying a liquid as a dispersed phase from the second liquid supply source 18 to the second liquid reservoir m ₂ of the microfluidic chip 16.

According to this apparatus, first, the lid is placed over the respective third reservoir m ₃ of the microfluidic chip 16, closed upper lid 10b of the chamber 10, while the first valve 13 is opened, the The second valve 15 is closed and the pump 12 is activated, and the air in the chamber 10 is exhausted. Then, when the inside of the chamber 10 is in a certain reduced pressure state, the first valve is closed and the pump 12 is stopped, and the microfluidic chip 16 is deaerated.

After a certain period of time, the second valve 15 is opened and air is taken into the chamber 10 again. When the inside of the chamber 10 becomes substantially equal to the atmospheric pressure, the first liquid supply source 17 becomes a continuous phase. The liquid is injected into the first liquid reservoir m ₁ of the microfluidic chip 16 through the first liquid supply pipe 19, and at the same time, the liquid that becomes the dispersed phase from the second liquid supply source 18 is supplied to the second liquid supply pipe 19. 20 is injected into the _second liquid reservoir m ₂ of the microfluidic chip 16.
Then, when the autonomous production process of fine droplets in a microfluidic chip 16 is completed, with the top cover 10b is removed, the third reservoir m ₃ lid is removed from the generated microdroplets external To be taken out.

DESCRIPTION OF SYMBOLS 1 Chip body 2 1st hole 3 2nd hole 4 3rd hole 5 1st groove | channel 6 2nd groove | channel 7 3rd groove | channel 8 Substrate 9 Lid 10 Chamber 10a Chamber body 10b Upper lid 10c O-ring 11 Exhaust pipe 12 pump 13 first valve 14 leak pipe 15 second valve 16 microfluidic chip 17 first liquid supply source 18 second liquid supply source 19 first liquid supply pipe 20 second liquid supply pipe m ₁ first 1 liquid reservoir m ₂ second liquid reservoir m ₃ third liquid reservoir n ₁ first micro flow channel n ₂ second micro flow channel n ₃ third micro flow channel u liquid w emulsion to be a continuous phase

Claims (10)

A method of producing microdroplets using a microfluidic chip,
(1) A plate-like chip body formed of a synthetic resin capable of occluding gas, and one surface of the chip body formed of the same type of synthetic resin as the synthetic resin or another type of synthetic resin or glass And a substrate bonded in a hermetically sealed state, and are connected to the chip body at a single point extending from the bottom of the first to third liquid reservoirs, respectively. Preparing a microfluidic chip provided with first to third microchannels;
(2) After covering the third liquid reservoir of the microfluidic chip, degassing the microfluidic chip by placing the microfluidic chip under reduced pressure for a predetermined time;
(3) The degassed microfluidic chip is placed under the atmospheric pressure while the third liquid reservoir is covered with the lid, and the second liquid is injected into the first liquid reservoir while the second phase is injected. The liquid that becomes the dispersed phase is injected into the liquid reservoir, and the liquid that becomes the continuous phase and the liquid that becomes the dispersed phase from the first and second liquid reservoirs, respectively, using the gas occlusion action of the synthetic resin. A liquid that flows toward the third liquid reservoir through the first and second microchannels, forms an emulsion in the third microchannel, and becomes a liquid that becomes the dispersed phase in the third reservoir. And collecting the microdroplets together with the liquid as the continuous phase.   2. The method according to claim 1, wherein each of the first to third microchannels tapers from a point before the connecting point to the connecting point.   Each of the first to third micro-channels has the same depth over its entire length, and a wide part extending from the liquid reservoir concerned to the point before the connection point, and the wide part The method according to claim 2, comprising a tapered portion that is gradually narrowed and connected to the tip, and a narrow portion that extends from the tip of the tapered portion to the connecting point.   The chip body of the microfluidic chip is provided with each one of the first to third liquid reservoirs, and the first to third microchannels are the first and second microchannels. One and the third microchannel are in a straight line, and the other of the first and second microchannels is one of the third macrochannel and the first and second microchannels. 4. The method according to claim 1, wherein the points are connected to each other in a T shape in an arrangement orthogonal to each other. 5.   The chip body of the microfluidic chip is provided with each one of the first to third liquid reservoirs, a pair of the first microchannels extends from the first liquid reservoir, and the first microflow The method according to any one of claims 1 to 3, wherein a set of paths and the set of second and third microchannels are connected to each other at the one point in a cross shape.   The chip body of the microfluidic chip is provided with the two first liquid reservoirs and the second and third liquid reservoirs, each of which has two lines extending from the two first liquid reservoirs. The set of said 2nd micro flow path and the set of said 2nd and 3rd flow paths are mutually connected in the shape of a cross at the said one point. The method described in 1.   The method according to claim 1, wherein a volume of the third liquid reservoir is larger than a volume obtained by adding the first and second liquid reservoirs.   The method according to claim 1, wherein the synthetic resin capable of occluding the gas is polydimethylsiloxane (PDMS).   The method according to claim 1, wherein the lid for the third liquid reservoir is a glass plate. A chamber;
An exhaust pipe having one end connected to the chamber;
A pump connected to the other end of the exhaust pipe for exhausting from the chamber;
A first valve provided in the middle of the exhaust pipe;
A leak pipe branched and connected upstream of the first valve in the exhaust pipe;
A second valve provided in the middle of the leak pipe;
A microfluidic chip disposed in the chamber,
The microfluidic chip is:
A plate-like chip body formed from a synthetic resin capable of storing gas;
The synthetic resin is formed of the same type of synthetic resin or another type of synthetic resin or glass, and has a substrate bonded in an airtight manner to one surface of the chip body,
The chip body is provided with first to third liquid reservoirs and first to third microchannels connected to each other at a single point from the bottom of the first to third liquid reservoirs, respectively. ,further,
A lid capable of sealing the third liquid reservoir of the microfluidic chip;
A first liquid supply source disposed outside the chamber for supplying a liquid to be a continuous phase;
A second liquid supply source arranged outside the chamber for supplying a liquid to be a dispersed phase;
A first liquid supply pipe for supplying a liquid as the continuous phase from the first liquid supply source to the first liquid reservoir of the microfluidic chip;
And a second liquid supply pipe for supplying the liquid serving as the dispersed phase from the second liquid supply source to the second liquid reservoir of the microfluidic chip. Micro droplet production equipment.