CN117983335A - Microfluidic device for controllable preparation of polymer liquid drops and application method - Google Patents

Abstract

The invention relates to the technical field of droplet micro-fluidic, and discloses a micro-fluidic device for controllable preparation of polymer droplets and a use method thereof.

Description

Microfluidic device for controllable preparation of polymer liquid drops and application method

Technical Field

The invention relates to the technical field of droplet microfluidics, in particular to a microfluidic device for controllably preparing polymer droplets and a use method thereof.

Background

The micro-droplet technology is a micro-liquid manipulation technology which is rapidly rising in the field of micro-fluidic chips in recent years. The core principle is to introduce two liquids which are not compatible with each other, one being the continuous phase and the other being the dispersed phase. The two phases are input into the chip through different inlets, and in the micro-channel, the disperse phase is sheared by the continuous phase under the action of shearing force, so as to form a series of micro-droplets with uniform particle size. Each micro-droplet is independently wrapped by a continuous phase and isolated from the outside, thus forming a closed system. Thus, each micro-droplet can be considered a micro-reaction system, with the potential to complete a set of chemical or biological reactions. The micro droplets are mutually independent, so that the reaction conditions are stably controlled, and the reliability of the reaction result is ensured.

Currently, the field of microfluidics has been focused on traditional newtonian droplets for a long time, whereas recent research has focused on polymer droplets with non-newtonian properties (e.g., viscoelastic properties). The research shows wide application prospect, and covers a plurality of fields such as drug delivery systems, biomedical analysis, chemical synthesis and reaction engineering. However, polymer droplets exhibit variable viscosity or rheological properties under external stress, which presents new challenges for controllable preparation of polymer droplets in microfluidic systems.

The currently published patent (ZL 201610641007.0) discloses a method for large-scale droplet preparation of microfluidic modules. The invention employs a multi-stage modular amplification strategy in which the modular design includes two amplification processes in parallel and stacked. In the implementation, the fluid flow velocity in the branch flow channels is equally distributed through the serpentine channels, eight micro-channels are arranged in parallel in a ring array mode in a single chip set, and then a module set is formed through stacking of ten chip sets. However, the chip structure is fixed, not modifiable, and is only suitable for batch preparation of microdroplets with newtonian characteristics, and cannot be used to achieve controlled scale preparation of microdroplets with complex viscoelastic polymers.

The presently disclosed patent (CN 113145038A) discloses a method and apparatus for preparing an oil emulsion adjuvant based on microfluidic technology. In practice, the device body is internally provided with a three-port tubing structure with multiple layers of through holes to form a flow focusing channel. The first port of the pipeline structure is connected with one end of a first hose in a sealing way through an inner pipe and a disperse phase conduit, and the other end of the first hose is used for introducing a disperse phase; the second port of the pipeline structure is connected with one end of a second hose in a sealing way after passing through the relay conduit and the continuous phase conduit, and the other end of the second hose is used for introducing the continuous phase; the third port of the pipeline structure is connected with one end of a third hose in a sealing way through an outlet conduit, and the other end of the third hose is used for leading out the generated oil emulsion adjuvant. Although the device is simple in structure and modularized, the micro-droplet preparation method of the device usually needs offline measurement to characterize, which causes inconvenience and inefficiency. In addition, the method is only suitable for producing droplets with newtonian characteristics, limiting its application in achieving controlled scale preparation of complex viscoelastic polymer microdroplets.

Therefore, how to provide a microfluidic device with a simple structure and controllable process for the preparation process of polymer droplets is a problem to be solved by those skilled in the art.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide a microfluidic device for controllably preparing polymer droplets and a use method thereof, so as to solve the technical problem of inconsistent droplet properties caused by variable viscosity and rheological properties in the process of generating the polymer droplets.

The invention is realized by the following technical scheme:

In a first aspect, a microfluidic device for the controllable preparation of polymer droplets comprises a microfluidic chip, a dispersed phase solution collection container assembly, a continuous phase solution collection container assembly, a polymer solution collection container, a spectrometer, and a computer; the microfluidic chip is provided with a flow focusing micro-channel structure, and the flow focusing micro-channel structure is provided with a plurality of inlet openings and an outlet opening; the device comprises a flow focusing micro-channel structure, a disperse phase solution collecting container assembly, a continuous phase solution collecting container assembly, a spectrometer and a computer, wherein one end of the flow focusing micro-channel structure, which is close to the outlet, is provided with a shrinking channel structure, the disperse phase solution collecting container assembly and the continuous phase solution collecting container assembly are correspondingly connected to a plurality of inlets of the flow focusing micro-channel structure, the outlet of the flow focusing micro-channel structure is connected with the polymer solution collecting container, the output end of the polymer solution collecting container is connected to the computer through the spectrometer, and the control end of the computer is respectively connected with the drive ends of the disperse phase solution collecting container assembly and the continuous phase solution collecting container assembly.

Preferably, the microfluidic chip comprises a sealing layer, a chip layer and a basal layer which are sequentially stacked from top to bottom, a plurality of lead-in ports are arranged on the sealing layer, the flow focusing micro-channel structure is arranged on the chip layer, and the lead-out ports are arranged on the basal layer.

Furthermore, the corners of the sealing layer, the chip layer and the basal layer are respectively provided with a plurality of fixing holes, and the sealing layer, the chip layer and the basal layer are combined and fixed through the fixing holes.

Further, the plurality of inlets comprise a disperse phase fluid inlet and two continuous phase fluid inlets, the disperse phase fluid inlet is connected with the disperse phase solution collecting container assembly, and the two continuous phase fluid inlets are respectively connected with the continuous phase solution collecting container assembly.

Further, the dispersed phase solution collecting container assembly comprises a dispersed phase solution collecting container and a first plunger pump; the output end of the disperse phase solution collecting container is connected to the disperse phase fluid inlet through a first plunger pump, and the driving end of the first plunger pump is connected with the control end of the computer.

Further, the continuous phase solution collection vessel assembly comprises a continuous phase solution collection vessel and a second plunger pump; the output end of the continuous phase solution collecting container is connected to two continuous phase fluid inlets through the second plunger pump rear branch, and the driving end of the second plunger pump is connected with the control end of the computer.

Further, the flow focusing micro-channel structure is in a crisscross channel structure and comprises a disperse phase lead-in channel, a continuous phase lead-in channel and a micro-droplet lead-out channel; the continuous phase inlet channel is arranged between the disperse phase inlet channel and the micro-droplet outlet channel and is perpendicular to the disperse phase inlet channel and the micro-droplet outlet channel, wherein the disperse phase inlet channel is communicated with the disperse phase fluid inlets, two ends of the continuous phase inlet channel are respectively communicated with the two continuous phase fluid inlets, one end, close to the outlet, of the micro-droplet outlet channel is provided with a micro-droplet collecting outlet, and the micro-droplet collecting outlet is communicated with the outlet.

Further, the shrinking channel structure is arranged at one end of the micro-droplet outgoing channel close to the continuous phase incoming channel, and comprises two rectangular blocks, wherein the two rectangular blocks are respectively fixed on the sealing layer and the basal layer, and a gap is formed between the two rectangular blocks for forming droplets after the solution passes through.

Further, the chip layer is prepared by using one or more of polymethyl methacrylate, polydimethylsiloxane or polystyrene.

In a second aspect, a method for using a microfluidic device for controllably preparing polymer droplets is based on the above microfluidic device for controllably preparing polymer droplets, and the specific process is as follows:

Preparing polymer disperse phase solution and continuous phase solution in a disperse phase solution collecting container assembly and a continuous phase solution collecting container assembly respectively, controlling the disperse phase solution collecting container assembly and the continuous phase solution collecting container assembly respectively by using a computer, conveying the polymer disperse phase solution and the continuous phase solution into a microfluidic chip to form polymer solution, generating polymer liquid drops by the polymer solution under the action of interfacial tension, conveying the polymer liquid drops into the polymer solution collecting container, automatically sampling by using a spectrometer controlled by the computer, monitoring the properties of the polymer liquid drops, and further automatically controlling the flow rates of two fluids, thereby realizing full-automatic and accurate control of the polymer liquid drops.

Compared with the prior art, the invention has the following beneficial technical effects:

The invention provides a microfluidic device for controllably preparing polymer liquid drops, which is characterized in that a disperse phase solution collecting container assembly and a continuous phase solution collecting container assembly are used for collecting the disperse phase solution and the continuous phase solution, the disperse phase solution collecting container assembly and the continuous phase solution collecting container assembly are controlled by a computer to convey the two solutions into a flow focusing micro-channel structure of a microfluidic chip to form the polymer solution, the polymer solution forms the polymer liquid drops after passing through a shrinking channel structure of the flow focusing micro-channel structure, the shrinking channel structure realizes the highly precise control of the generation process of the polymer liquid drops, the highly controllable formation of the liquid drops is realized by adjusting the size of the shrinking structure and the regulation of the wettability of a chip layer, and the microfluidic device has remarkable advantages in solving the problem of inconsistent property of the liquid drops in the prior art.

Further, the microfluidic chip comprises a sealing layer, a chip layer and a substrate layer which are sequentially stacked from top to bottom, a plurality of inlet openings are formed in the sealing layer, a flow focusing micro-channel structure is arranged on the chip layer, the outlet openings are formed in the substrate layer, the flow focusing micro-channel structure is of a crisscross channel structure, the polymer solution can be effectively controlled by fusing the geometric constraint type microfluidic chip with the crisscross flow focusing micro-channel structure and a liquid phase interface infiltration principle, the shrinking channel structure is arranged at one end of a micro-droplet outlet channel close to a continuous phase inlet channel, the shrinking channel structure comprises two rectangular blocks, the two rectangular blocks are respectively fixed on the sealing layer and the substrate layer, gaps are formed between the two rectangular blocks, the droplet formation is controllably controlled by controlling the size of the gaps between the two rectangular blocks, and meanwhile, the consistency of droplet properties is ensured.

The invention provides a use method of a microfluidic device for controllably preparing polymer liquid drops, which realizes full-automatic control of the polymer liquid drop generation process through a microfluidic chip, a disperse phase solution collecting container assembly, a continuous phase solution collecting container assembly, a polymer solution collecting container, a spectrometer and a computer. The system provides instant feedback for production through real-time online spectrum monitoring, and can effectively monitor and adjust the properties of polymer liquid drops, thereby improving the accuracy and efficiency of the process and providing an advanced and full-automatic polymer liquid drop generation scheme for industrial production.

Drawings

FIG. 1 is a schematic diagram of a microfluidic device according to the present invention;

FIG. 2 is a schematic perspective exploded view of a microfluidic chip according to the present invention;

FIG. 3 is a schematic diagram of a chip layer channel structure according to the present invention;

FIG. 4 is a schematic diagram of a cross-sectional structure of a microfluidic chip and polymer droplet generation in accordance with the present invention;

Fig. 5 (a) shows the volumes of polymer droplets of different relaxation times at different viscosities prepared in example 3, and (b) shows the volumes of polymer droplets of different relaxation times at different flow ratios prepared in example 3.

In the figure: 1-a microfluidic chip; 21-a dispersed phase solution collection vessel; 22-a continuous phase solution collection vessel; 23-a polymer solution collection vessel; 31-a first plunger pump; 32-a second plunger pump; 4-a computer; 5-capping layer; 6-chip layer; 7-a substrate layer; 8-a disperse phase fluid inlet; 9-continuous phase fluid inlet; 10-disperse phase introduction channel; 11-continuous phase introduction channel; 12-a collapsed channel structure; 13-a microdroplet extraction channel; 14-a micro-droplet collection outlet; 15-fixing holes; 16-spectrometer; 17-outlet.

Detailed Description

In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.

The invention is described in further detail below with reference to the attached drawing figures:

The invention aims to provide a microfluidic device for controllably preparing polymer liquid drops and a use method thereof, so as to solve the technical problem of inconsistent liquid drop properties caused by variable viscosity and rheological property in the process of generating the polymer liquid drops.

Example 1

Referring to fig. 1, in one embodiment of the present invention, there is provided a microfluidic device for the controlled preparation of polymer droplets, comprising a microfluidic chip 1, a dispersed phase solution collection container assembly, a continuous phase solution collection container assembly, a polymer solution collection container 23, a spectrometer 16, and a computer 4; the microfluidic chip 1 is provided with a flow focusing micro-channel structure, and the flow focusing micro-channel structure is provided with a plurality of inlet ports and an outlet port 17; the end of the flow focusing micro-channel structure, which is close to the outlet 17, is provided with a shrinking channel structure 12, the disperse phase solution collecting container component and the continuous phase solution collecting container component are correspondingly connected to a plurality of inlet of the flow focusing micro-channel structure, the outlet 17 of the flow focusing micro-channel structure is connected with a polymer solution collecting container 23, the output end of the polymer solution collecting container 23 is connected to a computer 4 through a spectrometer 16, and the control end of the computer 4 is respectively connected with the driving ends of the disperse phase solution collecting container component and the continuous phase solution collecting container component.

Specifically, according to fig. 2, the microfluidic chip 1 includes a capping layer 5, a chip layer 6 and a substrate layer 7 stacked in sequence from top to bottom, a plurality of inlet ports are disposed on the capping layer 5, the flow focusing microchannel structure is disposed on the chip layer 6, and the outlet ports 17 are disposed on the substrate layer 7.

Wherein, the corners of the sealing layer 5, the chip layer 6 and the basal layer 7 are respectively provided with a plurality of fixing holes 15, and are combined and fixed through the fixing holes 15.

The plurality of introducing ports comprise a disperse phase fluid inlet 8 and two continuous phase fluid inlets 9, wherein the disperse phase fluid inlet 8 is connected with a disperse phase solution collecting container assembly, and the two continuous phase fluid inlets 9 are respectively connected with the continuous phase solution collecting container assembly.

Wherein the dispersed phase solution collecting container assembly includes a dispersed phase solution collecting container 21 and a first plunger pump 31; the output end of the disperse phase solution collecting container 21 is connected to the disperse phase fluid inlet 8 through a first plunger pump 31, and the driving end of the first plunger pump 31 is connected with the control end of the computer 4.

Wherein the continuous phase solution collection vessel assembly comprises a continuous phase solution collection vessel 22 and a second plunger pump 32; the output end of the continuous phase solution collecting container 22 is connected to the two continuous phase fluid inlets 9 through the second plunger pump 32 and then branched, and the driving end of the second plunger pump 32 is connected with the control end of the computer 4.

Wherein, according to fig. 3, the flow focusing microchannel structure is in a crisscross channel structure, comprising a disperse phase introduction channel 10, a continuous phase introduction channel 11 and a micro droplet extraction channel 13; the continuous phase inlet channel 11 is arranged between the disperse phase inlet channel 10 and the micro-droplet outlet channel 13 and is perpendicular to the disperse phase inlet channel 10 and the micro-droplet outlet channel 13, wherein the disperse phase inlet channel 10 is communicated with the disperse phase fluid inlet 8, two ends of the continuous phase inlet channel 11 are respectively communicated with the two continuous phase fluid inlets 9, one end, close to the outlet 17, of the micro-droplet outlet channel 13 is provided with a micro-droplet collecting outlet 14, and the micro-droplet collecting outlet 14 is communicated with the outlet 17.

Wherein, according to fig. 4, a shrinking channel structure 12 is arranged at one end of the micro-droplet outgoing channel 13 near the continuous phase incoming channel 11, the shrinking channel structure 12 comprises two rectangular blocks, the two rectangular blocks are respectively fixed on the sealing layer 5 and the substrate layer 7, and a gap is formed between the two rectangular blocks for forming droplets after the solution passes through.

The chip layer 6 in this embodiment is prepared by using one or more of polymethyl methacrylate, polydimethylsiloxane or polystyrene.

In this embodiment, the size of the microfluidic chip 1 is about (100-200 mm) × (50-100 mm), and the thicknesses of the cover layer 5, the chip layer 6 and the base layer 5 are all about 2-4mm, preferably 2mm; the size of the dispersed phase introduction passage 10 is about (10-20 mm) × (0.1-1 mm); the size of the continuous phase introduction channel 11 is about (10-20 mm) x (0.05-1 mm), and the size of the micro droplet extraction channel 13 is about (10-40 mm) x (0.1-1 mm); the two rectangular blocks of the collapsed channel structure 12 have a size of (0.1-0.5 mm) x (0.02-0.1 mm);

The working principle of the geometrically constrained micro-fluidic chip based on the liquid phase interface infiltration principle in the embodiment is as follows: for the process of preparing the high-viscoelasticity polymer liquid drop, a chip layer material with a larger continuous phase liquid contact angle is selected, and meanwhile, the size of a shrinkage-protruding structure is reduced. By changing the interfacial tension, precise control over flow patterns and drop volumes during polymer drop generation is achieved.

Example 2

The embodiment provides a use method of a microfluidic device for controllable preparation of polymer droplets, which is based on the microfluidic device for controllable preparation of polymer droplets, and the specific process is as follows:

Preparing polymer disperse phase solution and continuous phase solution in a disperse phase solution collecting container assembly and a continuous phase solution collecting container assembly respectively, controlling the disperse phase solution collecting container assembly and the continuous phase solution collecting container assembly respectively by using a computer 4, conveying the polymer disperse phase solution and the continuous phase solution into a microfluidic chip 1 to form polymer solution, generating polymer liquid drops under the action of interfacial tension by the polymer solution, conveying the polymer liquid drops into a polymer solution collecting container 23, automatically sampling by a spectrometer 16 controlled by the computer 4, monitoring the properties of the polymer liquid drops, automatically controlling the flow rates of the two fluids, and realizing full-automatic and accurate control of the polymer liquid drops.

In this embodiment, when the two fluids are contacted in the microfluidic chip, the polymer dispersed phase forms polymer droplets under the combined action of the elastic force, the adhesive force and the surface tension. The polymer droplet generation process is monitored in real time by an on-line spectrometer to obtain spectroscopic information about the droplet properties. The polymer solution collecting container 23 effectively collects generated polymer droplets, and the computer controls the flow rate ratio of the plunger pump by processing data of the online spectrometer, so that a fully-automatic controllable polymer droplet generation process is realized.

The specific usage method in this embodiment is as follows:

(1) Solution preparation

Before the formation of the polymer droplets is carried out, a polymer dispersed phase solution and a continuous phase solution are prepared. This step requires careful selection and precise proportioning of the two different solutions to ensure that they meet specific experimental requirements. Solutions of the polymer dispersed phase and the continuous phase are formulated and placed in a dispersed phase solution collection vessel assembly and a continuous phase solution collection vessel assembly, respectively.

(2) Flow rate control

The flow rates of the two plunger pumps 3 are controlled by the computer 4, and the solutions of the polymer dispersed phase and the continuous phase which are configured in advance are accurately delivered to the microfluidic chip 1. In this step, precise flow rate regulation is critical to ensure subsequent droplet generation. The flow rates of the plunger pumps 3 are coordinated, avoiding unnecessary droplet generation instability.

(3) Microfluidic chip operation

The microfluidic chip 1 adopts a geometric constraint structure, which comprises a tapered channel structure 12. Such a design allows the polymer solution to be closely controlled during flow, thereby forming stable polymer droplets under the influence of interfacial tension. The microfluidic chip 1 delivers the generated droplets to a polymer solution collection container 23.

(4) On-line spectral monitoring

After the polymer droplets enter the polymer solution collection vessel 23, they are automatically sampled by an on-line spectrometer controlled by the computer 4, and the properties of the droplets are monitored and analyzed in real time. The monitoring result of the spectrometer is used as feedback information, key data support is provided for subsequent control, and the composition and the characteristics of liquid drops are accurately grasped

(5) Automatic flow rate adjustment

Based on the monitoring result of the online spectrometer, the computer 4 realizes automatic adjustment of the flow rates of the two phases through an intelligent control system. The feedback regulation mechanism ensures the full-automatic and accurate control of the polymer droplet generation process. The automatic adjustment of the flow rate ensures that the mass and properties of the droplets are accurately controlled.

Example 3

In this embodiment, taking the preparation of polymer micro-droplets with relaxation time of 0.00002-0.2 s and viscosity of 0.01-0.1 kg·m ^-1·s^-1 as an example, the method for controlling the micro-flow control of the polymer micro-droplets based on the geometric constraint type micro-flow control chip is described as follows:

(1) Preparing a disperse phase and a continuous phase fluid

Polymers with different relaxation times and different viscosities are prepared as a disperse phase. Newtonian fluid having a density of 930 kg.m ^-3 and a viscosity of 0.01 kg.m ^-1·s^-1 was used as the continuous phase.

(2) Preparation of Polymer microdroplets

The preparation was performed using the microfluidic device shown in fig. 1. The polymer disperse phase and the continuous phase are respectively contained in two collecting containers, the polymer disperse phase fluid is injected into the microfluidic chip at the flow rate of 0.01-0.08 m.s ^-1 and the continuous phase at the flow rate of 0.06 m.s ^-1 through a plunger pump, and polymer liquid drops are generated under the action of interfacial tension and are conveyed to the collecting containers.

In the preparation process, a schematic perspective exploded view of the microfluidic chip is shown in fig. 2, and the microfluidic chip is composed of a capping layer 5, a chip layer 6 and a substrate layer 7 which are sequentially stacked. The dimensions of the various parts are as follows:

wherein the dimensions of the capping layer 5 are 100mm by 50mm by 2mm. The diameter of the inner dispersed phase fluid inlet 8 was 0.1mm and the diameter of the continuous phase fluid inlet 9 was 0.05mm. The diameter of the fixing hole 15 is 0.12mm.

The dimensions of the chip layer 6 are 100mm by 50mm by 2mm. The chip layer is prepared from hydrophobic polydimethylsiloxane. As shown in fig. 3, the size of the dispersed phase introduction channel 10 inside the chip layer was 30mm×0.1mm, the size of the continuous phase introduction channel 11 was 20mm×0.05mm, the size of the tapered channel structure 12 was 0.06mm×0.1mm, the size of the micro droplet extraction channel 13 was 0.1mm×40mm, and the diameter of the fixing hole 15 was 0.12mm.

Wherein the dimensions of the base layer 7 are 100mm by 50mm by 2mm. The diameters of the micro-droplet collecting outlet 14 and the outlet 17 were 0.1mm, and the diameters of the fixing holes 15 were 0.12mm.

Specifically, fig. 4 is a schematic diagram of a cross-sectional structure of a microfluidic chip and polymer droplet generation of the present invention. As shown in fig. 4, in the hydrophobic chip layer of the microfluidic chip, the polymer dispersed phase enters from the dispersed phase fluid inlet 8, passes through the dispersed phase inlet channel 10, and after the channel structure 12 is contracted, polymer micro droplets are generated, and the polymer micro droplets are discharged from the outlet channel 13.

Specifically, as shown in fig. 5 (a), for a polymer fluid having a relaxation time λ of 0.00002 to 0.2s and a viscosity η _d of 0.01 to 0.1kg·m ^-1·s^-1, a variation in the relaxation time and viscosity causes a difference in the elastic force and the viscous force to which the polymer microdroplet is subjected when the polymer microdroplet is generated, and thus a difference in the volume V of the polymer microdroplet is generated. As shown in fig. 5 (b), by controlling the two plunger pumps and adjusting the flow rate ratio U _c/U_d of the two fluids, the volume of the polymer micro-droplet can be precisely controlled.

In summary, the invention provides a microfluidic device for the controllable preparation of polymer droplets and a method of use. Firstly, a geometric constraint type micro-fluidic chip is fused with a cross flow focusing micro-channel structure and a liquid phase interface infiltration principle, and a uniquely designed abrupt shrinkage structure is used for realizing the highly fine control of the polymer droplet generation process. The design not only allows the realization of high controllability of droplet formation by adjusting the size of the tapered structure and the regulation and control of chip layer wettability, but also has significant advantages in solving the problem of inconsistent droplet properties in the conventional technology. Secondly, the invention introduces a microfluidic device based on real-time online spectrum monitoring, which comprises a plunger pump, a microfluidic chip, a collecting container, an online spectrometer and a computer, so that the full-automatic control of the polymer droplet generation process is realized. The system provides instant feedback for production through real-time online spectrum monitoring, and can effectively monitor and adjust the properties of polymer liquid drops, thereby improving the accuracy and efficiency of the process and providing an advanced and full-automatic polymer liquid drop generation scheme for industrial production.

Finally, it should be noted that: the above embodiments are only for illustrating the technical aspects of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those of ordinary skill in the art that: modifications and equivalents may be made to the specific embodiments of the invention without departing from the spirit and scope of the invention, which is intended to be covered by the claims.

Claims (10)

1. The microfluidic device for controllably preparing polymer droplets is characterized by comprising a microfluidic chip (1), a disperse phase solution collecting container assembly, a continuous phase solution collecting container assembly, a polymer solution collecting container (23), a spectrometer (16) and a computer (4); the microfluidic chip (1) is provided with a flow focusing micro-channel structure, and the flow focusing micro-channel structure is provided with a plurality of inlet ports and an outlet port (17); the one end that the flow focus microchannel structure is close to outlet (17) is equipped with and contracts passageway structure (12), disperse phase solution collection container subassembly and continuous phase solution collection container subassembly correspond to be connected to a plurality of inlets of flow focus microchannel structure, polymer solution collection container (23) are connected to outlet (17) of flow focus microchannel structure, the output of polymer solution collection container (23) is passed through spectrometer (16) is connected to computer (4), the drive end of disperse phase solution collection container subassembly and continuous phase solution collection container subassembly is connected respectively to the control end of computer (4).

2. The microfluidic device for controllable preparation of polymer droplets according to claim 1, wherein the microfluidic chip (1) comprises a cover layer (5), a chip layer (6) and a substrate layer (7) stacked sequentially from top to bottom, a plurality of inlet openings are arranged on the cover layer (5), the flow focusing microchannel structure is arranged on the chip layer (6), and the outlet openings (17) are arranged on the substrate layer (7).

3. The microfluidic device for controllable preparation of polymer droplets according to claim 2, wherein the corners of the cover layer (5), the chip layer (6) and the substrate layer (7) are provided with a plurality of fixing holes (15), and the fixing holes (15) are combined and fixed.

4. A microfluidic device for the controlled preparation of polymer droplets according to claim 2, characterized in that several inlets comprise one dispersed phase fluid inlet (8) and two continuous phase fluid inlets (9), said dispersed phase fluid inlet (8) being connected to a dispersed phase solution collection vessel assembly, and two of said continuous phase fluid inlets (9) being connected to a continuous phase solution collection vessel assembly, respectively.

5. A microfluidic device for the controlled preparation of polymer droplets according to claim 4, characterized in that the dispersed phase solution collection container assembly comprises a dispersed phase solution collection container (21) and a first plunger pump (31); the output end of the disperse phase solution collecting container (21) is connected to the disperse phase fluid inlet (8) through a first plunger pump (31), and the driving end of the first plunger pump (31) is connected with the control end of the computer (4).

6. A microfluidic device for the controlled preparation of polymer droplets according to claim 4, characterized in that the continuous phase solution collection vessel assembly comprises a continuous phase solution collection vessel (22) and a second plunger pump (32); the output end of the continuous phase solution collecting container (22) is connected to the two continuous phase fluid inlets (9) through the rear branch of the second plunger pump (32), and the driving end of the second plunger pump (32) is connected with the control end of the computer (4).

7. The microfluidic device for the controlled preparation of polymer droplets according to claim 4, wherein the flow focusing microchannel structure is a crisscross channel structure comprising a disperse phase inlet channel (10), a continuous phase inlet channel (11) and a microdroplet outlet channel (13); the continuous phase inlet channel (11) is arranged between the disperse phase inlet channel (10) and the micro-droplet outlet channel (13), and is perpendicular to the disperse phase inlet channel (10) and the micro-droplet outlet channel (13), wherein the disperse phase inlet channel (10) is communicated with the disperse phase fluid inlets (8), two ends of the continuous phase inlet channel (11) are respectively communicated with the two continuous phase fluid inlets (9), one end, close to the outlet (17), of the micro-droplet outlet channel (13) is provided with a micro-droplet collecting outlet (14), and the micro-droplet collecting outlet (14) is communicated with the outlet (17).

8. A microfluidic device for the controlled preparation of polymer droplets according to claim 7, characterized in that the tapered channel structure (12) is arranged at the end of the micro droplet extraction channel (13) close to the continuous phase introduction channel (11), the tapered channel structure (12) comprises two rectangular blocks, which are fixed on the cover layer (5) and the substrate layer (7), respectively, with a gap formed between the two rectangular blocks for the solution to pass through to form droplets.

9. A microfluidic device for the controlled preparation of polymer droplets according to claim 2, characterized in that the chip layer (6) is prepared by using one or more of polymethyl methacrylate, polydimethylsiloxane or polystyrene.

10. A method of using a microfluidic device for the controlled preparation of polymer droplets, based on any one of claims 1-9, characterized by the following specific procedures:

Preparing polymer disperse phase solution and continuous phase solution in a disperse phase solution collecting container assembly and a continuous phase solution collecting container assembly respectively, controlling the disperse phase solution collecting container assembly and the continuous phase solution collecting container assembly respectively by using a computer (4), conveying the polymer disperse phase solution and the continuous phase solution into a microfluidic chip (1) to form polymer solution, generating polymer liquid drops by the polymer solution under the action of interfacial tension, conveying the polymer liquid drops into a polymer solution collecting container (23), automatically sampling by using a spectrometer (16) controlled by the computer (4), monitoring the properties of the polymer liquid drops, automatically controlling the flow rates of two fluids, and realizing full-automatic and accurate control of the polymer liquid drops.