阅读说明：本技术 一种用双水相体系制备聚电解质微囊的微流控芯片及其制备方法和应用 (Micro-fluidic chip for preparing polyelectrolyte microcapsules by using aqueous two-phase system and preparation method and application thereof ) 是由 秦建华 刘海涛 赵孟乾 于 2019-11-28 设计创作，主要内容包括：本发明提供了一种用双水相体系制备聚电解质微囊的微流控芯片。该芯片为上下两层结构,上层为液路部分,由含聚电解质I的反应相入口,反应相通道,连续相入口,连续相通道,上层压缩空气入口,含聚电解质II的分散相入口,分散相通道,气动阀作用区,液滴运输通道,微囊形成通道,微囊出口组成；下层为气路部分,由下层压缩空气入口,气体通道,气动泵阀组成。该芯片基于传统的流动聚焦型微流控液滴芯片,集成气动泵阀系统制成。本发明可用于在双水相体系中一步原位制备聚电解质微囊。通过调节各入口液体流速、泵阀开关周期等参数可以得到预期尺寸的聚电解质微囊。该芯片有望在生物活性物质包封、药物负载与递送、细胞3D培养支架制备等生物学应用中发挥作用。(The invention provides a micro-fluidic chip for preparing polyelectrolyte microcapsules by using a two-aqueous-phase system. The chip is of an upper-layer and lower-layer structure, the upper layer is a liquid path part and consists of a reaction phase inlet containing polyelectrolyte I, a reaction phase channel, a continuous phase inlet, a continuous phase channel, an upper-layer compressed air inlet, a dispersed phase inlet containing polyelectrolyte II, a dispersed phase channel, a pneumatic valve action area, a droplet transportation channel, a microcapsule forming channel and a microcapsule outlet; the lower layer is a gas path part and consists of a lower layer compressed air inlet, a gas channel and a pneumatic pump valve. The chip is manufactured by integrating a pneumatic pump valve system based on a traditional flow focusing type micro-fluidic droplet chip. The method can be used for preparing the polyelectrolyte microcapsule in situ in a double aqueous phase system by one step. The polyelectrolyte microcapsule with expected size can be obtained by adjusting parameters such as flow rate of liquid at each inlet, switching period of a pump valve and the like. The chip is expected to play a role in biological applications such as bioactive substance encapsulation, drug loading and delivery, cell 3D culture scaffold preparation and the like.)

1. A micro-fluidic chip for preparing polyelectrolyte microcapsules by using a two-aqueous-phase system is characterized in that: the chip is of an upper layer and a lower layer, wherein the upper layer is a liquid path part and consists of a reaction phase inlet (1) containing polyelectrolyte I, a reaction phase channel (2), a continuous phase inlet (3), a continuous phase channel (4), an upper layer compressed air inlet (5), a dispersed phase inlet (6) containing polyelectrolyte II, a dispersed phase channel (7), a pneumatic valve action area (8), a droplet transport channel (9), a microcapsule forming channel (10) and a microcapsule outlet (11);

wherein a reaction phase inlet (1) containing polyelectrolyte I is connected with a microcapsule outlet (11) through a reaction phase channel (2) and a microcapsule forming channel (10); the continuous phase inlet (3) is connected with the microcapsule outlet (11) through the continuous phase channel (4), the droplet transportation channel (9) and the microcapsule forming channel (10); the upper layer compressed air inlet (5) is used for introducing compressed air for controlling the lower layer air path; a dispersed phase inlet (6) containing polyelectrolyte II is connected with a microcapsule outlet (11) through a dispersed phase channel (7), a pneumatic valve action area (8), a droplet transport channel (9) and a microcapsule forming channel (10);

the lower layer is a gas path part and consists of a lower layer compressed air inlet (12), a gas channel (13) and a pneumatic pump valve (14); the lower layer compressed air inlet (12) is opposite to the upper layer compressed air inlet (5) and is connected with a pneumatic pump valve (14) through a gas channel (13).

2. The microfluidic chip for preparing polyelectrolyte microcapsules according to claim 1, wherein the polyelectrolyte microcapsules are prepared from a two-aqueous-phase system, and the microfluidic chip comprises: reaction phase liquid enters the chip from the reaction phase inlet (1) and sequentially passes through the reaction phase channel (2) and the microcapsule forming channel (10) to reach the microcapsule outlet (11).

3. The microfluidic chip for preparing polyelectrolyte microcapsules according to claim 1, wherein the polyelectrolyte microcapsules are prepared from a two-aqueous-phase system, and the microfluidic chip comprises: the continuous phase liquid enters the chip from the continuous phase inlet (3), and reaches the microcapsule outlet (11) through the continuous phase channel (4), the droplet transport channel (9) and the microcapsule forming channel (10) in sequence.

4. The microfluidic chip for preparing polyelectrolyte microcapsules according to claim 1, wherein the polyelectrolyte microcapsules are prepared from a two-aqueous-phase system, and the microfluidic chip comprises: the dispersed phase liquid enters the chip from a dispersed phase inlet (6) and sequentially passes through a dispersed phase channel (7), a pneumatic valve action area (8), a liquid drop transport channel (9) and a microcapsule forming channel (10) to reach a microcapsule outlet (11).

5. The microfluidic chip for preparing polyelectrolyte microcapsules according to claim 1, wherein the polyelectrolyte microcapsules are prepared from a two-aqueous-phase system, and the microfluidic chip comprises: compressed air enters the chip from the upper air inlet (5) and sequentially passes through the lower air inlet (12) and the air channel (13) to reach the pneumatic pump valve (14); the diameter of the pneumatic pump valve is 0.5-2mm, the upper wall of the pneumatic pump valve is 200-500 mu m thinner than that of the gas channel, and the pneumatic pump valve can generate elastic deformation under the condition of gas blowing, so that dispersed phase fluid in an upper layer liquid path is disturbed.

6. The microfluidic chip for preparing polyelectrolyte microcapsules according to claim 1, wherein the polyelectrolyte microcapsules are prepared from a two-aqueous-phase system, and the microfluidic chip comprises: the width of the reaction phase channel (2) and the microcapsule forming channel (10) of the upper layer chip is 100-400 mu m, and the length of the microcapsule forming channel (10) is 1-4 cm; the widths of the continuous phase channel (4), the disperse phase channel (7) and the droplet transport channel (9) are 50-250 μm, and the heights of all upper chip channels are 100-300 μm; the height and width of the lower chip channel are as follows: 50-300 μm.

7. A method for preparing a microfluidic chip according to any one of claims 1 to 6, wherein the method comprises: preparing a template of SU-8 photoresist on a monocrystalline silicon piece or a dust-free glass piece by using a conventional soft lithography method, then pouring a Polydimethylsiloxane (PDMS) prepolymer on the SU-8 photoresist template, and heating at 80 ℃ for 1-3 hours for cross-linking polymerization to prepare a PDMS chip; the chip is based on a traditional flow focusing type micro-fluidic liquid drop chip and is manufactured by integrating a pneumatic pump valve system on the lower layer.

8. A method for preparing polyelectrolyte microcapsules by using the microfluidic chip of any one of claims 1 to 6, wherein the method comprises the following steps: the dispersed phase channel (7) and the continuous phase channel (4) are converged to the droplet transport channel (9) to form a flow focusing intersection; the position of the pneumatic pump valve (14) is right below the pneumatic valve action area (8), and the dispersed phase channel (7) is periodically extruded through two states of aeration and rest of the pump valve (14), so that the dispersed phase enters the continuous phase discontinuously, and water-in-water droplets are stably and efficiently formed; the polyelectrolyte II carried by the liquid drop meets the polyelectrolyte I carried by the reaction phase in a microcapsule forming channel (10), and under the action of molecular diffusion, the two polyelectrolytes with opposite charges are subjected to electrostatic complexation near the surface of the liquid drop, so that the polyelectrolyte microcapsule can be formed.

Technical Field

The invention belongs to the fields of microfluidic technology, material chemistry and the like, and particularly relates to a microfluidic chip for preparing polyelectrolyte microcapsules by using a two-aqueous-phase system.

Background

The polyelectrolyte is a high molecular substance with a large amount of residual charges on the surface, and two polyelectrolytes with different charging characteristics can directly generate electrostatic complexation reaction in an aqueous solution to obtain a composite polymer. The polymer can be in the forms of films, microspheres, microcapsules and the like, and is widely applied to the fields of food engineering, drug carriers, tissue engineering and the like due to good biocompatibility and mechanical strength.

In polyelectrolyte composite materials with various shapes, the microcapsule is considered as a good micro-carrier, can be used for loading and delivering medicines, bacteria, cells and the like, and has wide application prospects in the fields of biology, medicine, pharmacy and the like. However, the traditional polyelectrolyte microcapsule forming method usually involves multi-step operations, wherein solid polyelectrolyte microspheres need to be prepared first, then polyelectrolytes with opposite charges are assembled on the surface layer of the microspheres, and finally, the inner microspheres are dissolved to obtain the hollow microcapsules. The preparation process is complex and time-consuming, has large damage to the loaded object and low loading efficiency, and is not beneficial to the wide application of the microcapsule.

In recent years, the microfluidic droplet technology has been developed greatly, and various functionalized microspheres and microcapsules with different morphologies can be accurately prepared, which makes great contribution in the fields of materials science, biology, pharmacy and the like. And the aqueous two-phase system is introduced into the field of microfluidic droplets, so that the preparation of microspheres and microcapsules with more complex shapes becomes possible. And the possibility of industrialization of the prepared products is greatly increased due to the advantages of accurate controllability, easy integration and the like of the microfluidic technology. The invention is based on the traditional flow focusing type liquid drop micro-fluidic chip, integrates a pneumatic pump valve system, and designs and prepares the micro-fluidic chip which can be used for synthesizing polyelectrolyte microcapsules by an in-situ one-step method.

Disclosure of Invention

The invention aims to provide a micro-fluidic chip which is based on a conventional soft lithography method and integrates a pneumatic pump valve and can be used for preparing polyelectrolyte microcapsules in situ in one step.

The invention relates to a micro-fluidic chip for preparing polyelectrolyte microcapsules by using a two-aqueous-phase system, which comprises an upper layer structure and a lower layer structure: the upper layer is a liquid path part and consists of a reaction phase inlet containing polyelectrolyte I, a reaction phase channel, a continuous phase inlet, a continuous phase channel, an upper layer compressed air inlet, a dispersed phase inlet containing polyelectrolyte II, a dispersed phase channel, a pneumatic valve action area, a droplet transportation channel, a microcapsule forming channel and a microcapsule outlet; the lower layer is a gas path part and consists of a lower layer compressed air inlet, a gas channel and a pneumatic pump valve;

a reaction phase inlet containing polyelectrolyte I in the chip is connected with a microcapsule outlet through a reaction phase channel and a microcapsule forming channel; the continuous phase inlet is connected with the microcapsule outlet through the continuous phase channel, the droplet transport channel and the microcapsule forming channel; the upper layer compressed air inlet is used for introducing compressed air for controlling the lower layer air path; the dispersed phase inlet containing polyelectrolyte II is connected with the microcapsule outlet through a dispersed phase channel, a pneumatic valve action area, a droplet transport channel and a microcapsule forming channel; the lower layer compressed air inlet is opposite to the upper layer compressed air inlet and is connected with a pneumatic pump valve through a gas channel.

The flow sequence of the four fluids in the chip is as follows: reaction phase liquid enters the chip from the reaction phase inlet and sequentially passes through the reaction phase channel and the microcapsule forming channel to reach the microcapsule outlet; the continuous phase liquid enters the chip from the continuous phase inlet, sequentially passes through the continuous phase channel, the liquid drop transport channel and the microcapsule forming channel to reach the microcapsule outlet; the dispersed phase liquid enters the chip from the dispersed phase inlet, and then reaches the microcapsule outlet through the dispersed phase channel, the pneumatic valve action area, the droplet transportation channel and the microcapsule forming channel in sequence; compressed air enters the chip from the upper air inlet and sequentially passes through the lower air inlet and the air channel to reach the pneumatic pump valve; the diameter of the pneumatic pump valve is 0.5-2mm, the upper wall of the pneumatic pump valve is 200-500 mu m thinner than that of the gas channel, and the pneumatic pump valve can generate elastic deformation under the condition of gas blowing, so that dispersed phase fluid in an upper layer liquid path is disturbed.

The width of the reaction phase channel and the microcapsule forming channel of the upper chip is 100-400 mu m, and the length of the microcapsule forming channel is 1-4 cm; the widths of the continuous phase channel, the disperse phase channel and the droplet transportation channel are 50-250 mu m, and the heights of all the upper chip channels are 100-300 mu m; the height and width of the lower chip channel are as follows: 50-300 μm.

The invention provides a preparation method of a microfluidic chip, which comprises the following steps: preparing a template of SU-8 photoresist on a monocrystalline silicon piece or a dust-free glass piece by using a conventional soft lithography method, then pouring a Polydimethylsiloxane (PDMS) prepolymer on the SU-8 photoresist template, and heating at 80 ℃ for 1-3 hours for cross-linking polymerization to prepare a PDMS chip; the chip is based on a traditional flow focusing type micro-fluidic liquid drop chip and is manufactured by integrating a pneumatic pump valve system on the lower layer.

The invention provides a method for preparing polyelectrolyte microcapsules based on the microfluidic chip, wherein a dispersed phase channel 7 and a continuous phase channel 4 are converged to a droplet transport channel 9 to form a flow focusing intersection; the position of the pneumatic pump valve 14 is right below the pneumatic valve action area 8, and the dispersed phase channel is periodically extruded through two states of pump valve inflation and rest, so that the dispersed phase enters the continuous phase discontinuously, and double-aqueous-phase droplets are stably and efficiently formed; the liquid drop carries polyelectrolyte II to meet polyelectrolyte I carried by a reaction phase in a microcapsule forming channel 10, and under the action of molecular diffusion, two polyelectrolytes with opposite charges are subjected to electrostatic complexation near the surface of the liquid drop, so that the polyelectrolyte microcapsule can be formed.

The chip is a PDMS chip formed by using a conventional soft lithography method. The chip is manufactured by integrating a pneumatic pump valve system at the lower layer based on the traditional flow focusing type micro-fluidic droplet chip; wherein the dispersed phase channel and the continuous phase channel are converged to the droplet transport channel to form a flowing focused intersection; the position of the pneumatic pump valve is right below the action area of the pneumatic valve, and the dispersed phase channel is periodically extruded through two states of inflation and rest of the pump valve, so that the dispersed phase enters the continuous phase discontinuously, and double-aqueous-phase droplets are stably and efficiently formed; the polyelectrolyte II carried by the liquid drop meets the polyelectrolyte I carried by the reaction phase in a microcapsule forming channel, and under the action of molecular diffusion, the two polyelectrolytes with opposite charges are subjected to electrostatic complexation near the surface of the liquid drop, so that the polyelectrolyte microcapsule can be formed.

The invention has the beneficial effects that:

the invention can greatly simplify the preparation process of the polyelectrolyte microcapsule and increase the controllability of the preparation process. The stable and uniform polyelectrolyte microcapsule can be obtained by adjusting the flow rate of each phase fluid, the switching period of a pump valve and the like. The chip is expected to play a role in loading and delivering bioactive substances such as proteins, probiotics, cells and the like.

Drawings

Fig. 1 is a schematic diagram of a microfluidic chip for preparing polyelectrolyte microcapsules by using a two-aqueous-phase system, wherein: a upper layer liquid path chip; b, a lower layer gas circuit chip; c two layers of chip combination general diagram.

Wherein: 1 a reaction phase inlet containing polyelectrolyte I; 2 reaction phase channel; 3 a continuous phase inlet; 4 continuous phase channel; 5, laminating a compressed air inlet on the upper layer; 6 a dispersed phase inlet containing polyelectrolyte II; 7 dispersed phase channels; 8 pneumatic pump valve action area, 9 liquid droplet transport channel; 10 microcapsule forming channel; 11 a microcapsule outlet; 12 lower layer compressed air inlet (coinciding with the a middle and upper layer compressed air inlet 5); 13 a gas channel; 14 pneumatic pump valve.

FIG. 2 is a diagram of a microfluidic chip for preparing polyelectrolyte microcapsules by using a two-aqueous phase system in example 2.

Detailed Description

Firstly, designing and processing a micro-fluidic chip with a proper size according to actual requirements; then, a corresponding chip is prepared by utilizing a conventional soft lithography technology, and the generation, the size and the like of the microcapsule are regulated and controlled by combining a pump valve control system. The invention is further illustrated by the following figures and examples.

Example 1

A micro-fluidic chip for preparing polyelectrolyte microcapsules by using a two-aqueous-phase system is shown in figure 1, and comprises an upper layer structure and a lower layer structure: the upper layer is a liquid path part and consists of a reaction phase inlet 1 containing polyelectrolyte I, a reaction phase channel 2, a continuous phase inlet 3, a continuous phase channel 4, an upper layer compressed air inlet 5, a dispersed phase inlet 6 containing polyelectrolyte II, a dispersed phase channel 7, a pneumatic valve action area 8, a droplet transport channel 9, a microcapsule forming channel 10 and a microcapsule outlet 11; the lower layer is a gas path part and consists of a lower layer compressed air inlet 12, a gas channel 13 and a pneumatic pump valve 14;

a reaction phase inlet 1 containing polyelectrolyte I is connected with a microcapsule outlet 11 through a reaction phase channel 2 and a microcapsule forming channel 10; the continuous phase inlet 3 is connected with the microcapsule outlet 11 through the continuous phase channel 4, the droplet transport channel 9 and the microcapsule forming channel 10; the upper layer compressed air inlet 5 is used for introducing compressed air for controlling the lower layer air path; a dispersed phase inlet 6 containing polyelectrolyte II is connected with a microcapsule outlet through a dispersed phase channel 7, a pneumatic valve action area 8, a droplet transport channel 9 and a microcapsule forming channel 10; the lower layer compressed air inlet 12 is opposite to the upper layer compressed air inlet 5 and is connected with a pneumatic pump valve 14 through a gas channel 13;

the flow sequence of the four fluids in the chip is: reaction phase liquid enters the chip from the reaction phase inlet 1 and reaches the microcapsule outlet 11 through the reaction phase channel 2 and the microcapsule forming channel 9 in sequence; continuous phase liquid enters the chip from a continuous phase inlet 3 and sequentially passes through a continuous phase channel 4, a liquid drop transport channel 9 and a microcapsule forming channel 10 to reach a microcapsule outlet 11; the dispersed phase liquid enters the chip from the dispersed phase inlet 6, and then reaches the microcapsule outlet 11 through the dispersed phase channel 7, the pneumatic valve action area 8, the droplet transportation channel 9 and the microcapsule forming channel 10; compressed air enters the chip from the upper air inlet 5 and sequentially passes through the lower air inlet 12 and the air channel 13 to reach the pneumatic pump valve 14; the diameter of the pneumatic pump valve is 2mm, the upper wall of the pneumatic pump valve is 500 microns thinner than that of the gas channel, and the pneumatic pump valve can be elastically deformed under the condition of gas blowing, so that dispersed phase fluid in an upper layer liquid path is disturbed.

The width of the reaction phase channel of the upper chip and the microcapsule forming channel is 400 μm, and the length of the microcapsule forming channel is 4 cm; the continuous phase channel, the dispersed phase channel and the droplet transport channel had a width of 200 μm and the height of all upper chip channels was 300 μm. The height and the width of the lower chip channel are both 300 mu m;

the chip is a PDMS chip formed by using a conventional soft lithography method. Based on the traditional flow focusing type micro-fluidic droplet chip, the micro-fluidic droplet chip is manufactured by integrating a pneumatic pump valve system at the lower layer; wherein the disperse phase channel 7 and the continuous phase channel 4 converge to the droplet transport channel 9 to form a flow focusing intersection; the position of the pneumatic pump valve 14 is right below the pneumatic valve action area 8, and the dispersed phase channel 7 is periodically extruded through two states of inflation and rest of the pneumatic pump valve 14, so that the dispersed phase enters the continuous phase discontinuously, and water-in-water droplets are stably and efficiently formed; the polyelectrolyte II carried by the liquid drop meets the polyelectrolyte I carried by the reaction phase in the microcapsule forming channel 10, and under the action of molecular diffusion, the two polyelectrolytes with opposite charges are subjected to electrostatic complexation near the surface of the liquid drop, so that the polyelectrolyte microcapsule can be formed.

Example 2

A micro-fluidic chip for preparing polyelectrolyte microcapsules by using a two-aqueous-phase system comprises an upper layer structure and a lower layer structure: the upper layer is a liquid path part and consists of a reaction phase inlet 1 containing polyelectrolyte I, a reaction phase channel 2, a continuous phase inlet 3, a continuous phase channel 4, an upper layer compressed air inlet 5, a dispersed phase inlet 6 containing polyelectrolyte II, a dispersed phase channel 7, a pneumatic valve action area 8, a droplet transport channel 9, a microcapsule forming channel 10 and a microcapsule outlet 11; the lower layer is a gas path part and consists of a lower layer compressed air inlet 12, a gas channel 13 and a pneumatic pump valve 14;

a reaction phase inlet 1 containing polyelectrolyte I is connected with a microcapsule outlet 11 through a reaction phase channel 2 and a microcapsule forming channel 10; the continuous phase inlet 3 is connected with the microcapsule outlet 11 through the continuous phase channel 4, the droplet transport channel 9 and the microcapsule forming channel 10; the upper layer compressed air inlet 5 is used for introducing compressed air for controlling the lower layer air path; a dispersed phase inlet 6 containing polyelectrolyte II is connected with a microcapsule outlet 11 through a dispersed phase channel 7, a pneumatic valve action area 8, a droplet transport channel 9 and a microcapsule forming channel 10; the lower layer compressed air inlet 12 is opposite to the upper layer compressed air inlet 5 and is connected with a pneumatic pump valve 14 through a gas channel 13;

the flow sequence of the four fluids in the chip is: reaction phase liquid enters the chip from the reaction phase inlet 1 and reaches the microcapsule outlet 11 through the reaction phase channel 2 and the microcapsule forming channel 9 in sequence; continuous phase liquid enters the chip from a continuous phase inlet 3 and sequentially passes through a continuous phase channel 4, a liquid drop transport channel 9 and a microcapsule forming channel 10 to reach a microcapsule outlet 11; the dispersed phase liquid enters the chip from the dispersed phase inlet 6, and then reaches the microcapsule outlet 11 through the dispersed phase channel 7, the pneumatic valve action area 8, the droplet transportation channel 9 and the microcapsule forming channel 10; compressed air enters the chip from the upper air inlet 5 and sequentially passes through the lower air inlet 12 and the air channel 13 to reach the pneumatic pump valve 14; the diameter of the pneumatic pump valve is 1mm, the upper wall of the pneumatic pump valve is 400 microns thinner than that of the gas channel, and the pneumatic pump valve can be elastically deformed under the condition of gas blowing, so that dispersed phase fluid in an upper layer liquid path is disturbed.

The width of a reaction phase channel of the upper chip and a channel formed by the microcapsule is 250 micrometers, and the length of the channel formed by the microcapsule is 2 cm; the continuous phase channel, the dispersed phase channel and the droplet transport channel had widths of 150 μm and heights of all upper chip channels were 200 μm. The height and the width of the lower chip channel are both 200 mu m;

the chip shown in fig. 2 is a PDMS chip formed by a conventional soft lithography method. Based on the traditional flow focusing type micro-fluidic droplet chip, the micro-fluidic droplet chip is manufactured by integrating a pneumatic pump valve system at the lower layer; wherein the disperse phase channel 7 and the continuous phase channel 4 converge to the droplet transport channel 9 to form a flow focusing intersection; the position of the pneumatic pump valve 14 is right below the pneumatic valve action area 8, and the dispersed phase channel 7 is periodically extruded through two states of inflation and rest of the pneumatic pump valve 14, so that the dispersed phase enters the continuous phase discontinuously, and water-in-water droplets are stably and efficiently formed; the polyelectrolyte II carried by the liquid drop meets the polyelectrolyte I carried by the reaction phase in the microcapsule forming channel 10, and under the action of molecular diffusion, the two polyelectrolytes with opposite charges are subjected to electrostatic complexation near the surface of the liquid drop, so that the polyelectrolyte microcapsule can be formed.

Example 3

A micro-fluidic chip for preparing polyelectrolyte microcapsules by using a two-aqueous-phase system comprises an upper layer structure and a lower layer structure: the upper layer is a liquid path part and consists of a reaction phase inlet 1 containing polyelectrolyte I, a reaction phase channel 2, a continuous phase inlet 3, a continuous phase channel 4, an upper layer compressed air inlet 5, a dispersed phase inlet 6 containing polyelectrolyte II, a dispersed phase channel 7, a pneumatic valve action area 8, a droplet transport channel 9, a microcapsule forming channel 10 and a microcapsule outlet 11; the lower layer is a gas path part and consists of a lower layer compressed air inlet 12, a gas channel 13 and a pneumatic pump valve 14;

a reaction phase inlet 1 containing polyelectrolyte I is connected with a microcapsule outlet 11 through a reaction phase channel 2 and a microcapsule forming channel 10; the continuous phase inlet 3 is connected with the microcapsule outlet 11 through the continuous phase channel 4, the droplet transport channel 9 and the microcapsule forming channel 10; the upper layer compressed air inlet 5 is used for introducing compressed air for controlling the lower layer air path; a dispersed phase inlet 6 containing polyelectrolyte II is connected with a microcapsule outlet 11 through a dispersed phase channel 7, a pneumatic valve action area 8, a droplet transport channel 9 and a microcapsule forming channel 10; the lower layer compressed air inlet 12 is opposite to the upper layer compressed air inlet 5 and is connected with a pneumatic pump valve 14 through a gas channel 13;

the flow sequence of the four fluids in the chip is: reaction phase liquid enters the chip from the reaction phase inlet 1 and reaches the microcapsule outlet 11 through the reaction phase channel 2 and the microcapsule forming channel 9 in sequence; continuous phase liquid enters the chip from a continuous phase inlet 3 and sequentially passes through a continuous phase channel 4, a liquid drop transport channel 9 and a microcapsule forming channel 10 to reach a microcapsule outlet 11; the dispersed phase liquid enters the chip from the dispersed phase inlet 6, and then reaches the microcapsule outlet 11 through the dispersed phase channel 7, the pneumatic valve action area 8, the droplet transportation channel 9 and the microcapsule forming channel 10; compressed air enters the chip from the upper air inlet 5 and sequentially passes through the lower air inlet 12 and the air channel 13 to reach the pneumatic pump valve 14; the diameter of the pneumatic pump valve is 0.5mm, the upper wall of the pneumatic pump valve is 250 micrometers thinner than that of the gas channel, and the pneumatic pump valve can generate elastic deformation under the condition of gas blowing, so that dispersed phase fluid in an upper layer liquid path is disturbed.

The width of the reaction phase channel of the upper chip and the microcapsule forming channel is 150 μm, and the length of the microcapsule forming channel is 1 cm; the continuous phase channel, the dispersed phase channel and the droplet transport channel have a width of 100 μm and all the upper chip channels have a height of 150 μm. The height and the width of the lower chip channel are both 100 micrometers;

the chip is a PDMS chip formed by using a conventional soft lithography method. Based on the traditional flow focusing type micro-fluidic droplet chip, the micro-fluidic droplet chip is manufactured by integrating a pneumatic pump valve system at the lower layer; wherein the disperse phase channel 7 and the continuous phase channel 4 converge to the droplet transport channel 9 to form a flow focusing intersection; the position of the pneumatic pump valve 14 is right below the pneumatic valve action area 8, and the dispersed phase channel 7 is periodically extruded through two states of inflation and rest of the pneumatic pump valve 14, so that the dispersed phase enters the continuous phase discontinuously, and water-in-water droplets are stably and efficiently formed; the polyelectrolyte II carried by the liquid drop meets the polyelectrolyte I carried by the reaction phase in the microcapsule forming channel 10, and under the action of molecular diffusion, the two polyelectrolytes with opposite charges are subjected to electrostatic complexation near the surface of the liquid drop, so that the polyelectrolyte microcapsule can be formed.