A single-droplet separation chip controlled by a microvalve structure

Abstract

The present invention provides a single-droplet separation chip controlled by a microvalve structure, which is formed by bonding an upper substrate, an elastic membrane and a lower substrate from top to bottom; a droplet close-packed chamber, a fluid channel, a droplet dripping chamber are sequentially arranged in the upper substrate, an oil-phase channel intersecting with the fluid channel, and a capillary tube connected to the droplet dripping chamber; a gas channel is arranged in the lower substrate, which has at least one overlapping part with the fluid channel in the vertical direction, and the elastic membrane forms a microvalve structure with the ability to adjust flow resistance at the overlapping part; the droplet close-packed chamber is used to achieve the close arrangement of droplets, and the intersection structure of the fluid channel and the oil-phase channel and the microvalve structure together constitute a droplet interval control unit, and the droplet dripping chamber and the capillary tube are used for the formation and derivation of single-droplet dripping. The single-droplet separation chip provided by the present invention has the advantages of being easy to process and manufacture, low in price and simple to operate, and is also easy to be integrated with biochemical analysis chips, etc.

Description

Technical Field

[0001] The present invention relates to the field of droplet microfluidics, and more particularly to a single droplet separation chip controlled by a microvalve structure. Background Art

[0002] Technologies based on droplet microfluidics are currently widely used in the field of bioanalysis. Due to their high throughput and miniaturization characteristics, they have become powerful tools for researchers and experiments in fields such as genetics, immunology, and molecular biology. Droplet digital PCR technology (ddPCR) has higher sensitivity compared to traditional PCR technology. Droplet-based single-cell whole genome amplification (WGA) and sequencing, as well as secretion analysis, provide powerful technical means for the study of cell heterogeneity. With the development of droplet microfluidics-based technologies and the in-depth study of single cells, bacteria, viruses, etc., separating a single droplet from a droplet suspension has become a need, which is of great significance for analyzing the characteristics of single cells, bacteria, viruses, etc. and studying a small number of cells in a cell community.

[0003] Single-cell separation technology is one of the important research directions in microfluidics. Traditional cytological research studies cells from the perspective of a community, and the obtained indicators are the average values of the indicators of each cell in the community. In fact, due to genotype differences between different individual cells and the possible differences in phenotypes of cells with the same genotype affected by the environment. For the study of this difference, separating single cells is the basis and key of the research. General separation methods can be divided into three methods: flow cytometry, laser microdissection, and manual micromanipulation. Flow cytometry is the most widely used single-cell separation method, which has a relatively high throughput, but the equipment is expensive and the charging process of the charging ring may cause damage to the cells; laser microdissection has a low throughput and can only be used for single-cell separation of solid tissue sections; manual micromanipulation has a low throughput and has certain requirements for the operation level of technicians.

[0004] A microvalve is a microfluidic technology that can change the flow resistance or on / off state of a fluid pipeline. There are various forms of microvalves, which can be divided into two categories: passive valves and active valves. Passive valves do not require external force or external control, and they use the air pressure of the fluid itself or the property change under the action of an external field to achieve valve change; active valves, also known as active valves, require external power to achieve valve change. An air valve is one type of active valve, which is divided into two types: single-layer air valves and multi-layer air valves. A single-layer air valve fabricates the gas channel and the fluid channel on one layer, but it has requirements for the width of the fluid channel and requires a large area. Multi-layer air valves have a high integration degree. They were first used to realize micropumps and then widely used as a droplet sorting means.

[0005] The single-cell separation method based on microfluidic technology mainly includes two technical methods: cell capture and release, and microdroplet inkjet printing. Cell capture and release uses methods such as geometric structures, microvalves, optical tweezers, magnetic force, and electric power to capture cells, then rinses away the un-captured cells, and finally releases the captured cells to achieve single-cell separation. The rinsing process wastes the un-captured cells and only a limited number of cells can be captured in one operation. Single-cell separation requires individual release, so cell capture and release is a low-throughput method. Inkjet printing is the most widely used microfluidic single-cell separation method in industrial applications. It detects the distance between cells or droplets at the tip of the nozzle and then feeds back to deformable materials such as piezoelectric materials to control their deformation degree, spraying droplets of different sizes. This method has a high cost and complex equipment. An ideal single-droplet separation device should be stable in separation, small in size, and easy to operate.

[0006] CN201610747696.3 invented a system composed of a single-cell continuous flow unit, a buffer separation unit, and a droplet encapsulation unit. The single-cell continuous flow unit is used to break up aggregated and sedimented cell clusters to form a cell flow on the upper wall of the chip. The buffer separation unit exports the excess buffer, and then droplets encapsulating single cells are formed in the droplet encapsulation unit. However, this system lacks a part for exporting droplets and can only be used for on-chip single-droplet processing.

[0007] CN201410069484.5 describes a method for single-cell separation using a thin catheter. Droplets are generated inside the microfluidic chip and separated by being exported through the thin catheter. First, single cells are encapsulated during the droplet generation process, and then solenoid valves are used to sort the droplets to remove the un-encapsulated and multi-encapsulated cells. Finally, they are discharged through the thin catheter to achieve single-cell separation. However, this chip lacks a droplet spacing control unit, and droplet separation has a certain randomness, resulting in unstable separation effects. Summary of the Invention

[0008] The purpose of the present invention is to provide a single-droplet separation chip controlled by a microvalve structure, so as to solve the problem in the prior art of lacking a single-droplet separation device with a simple structure, stable separation effect, and low cost.

[0009] To solve the above technical problems, the present invention adopts the following technical solutions:

[0010] A single-droplet separation chip controlled by a microvalve is provided. The single-droplet separation chip is formed by bonding an upper substrate, an elastic film, and a lower substrate in sequence from top to bottom. A droplet close-packed chamber, a fluid channel, a droplet dripping chamber, and an oil-phase channel intersecting with the fluid channel are sequentially arranged in the upper substrate. A capillary tube connected to the droplet dripping chamber is also provided. A gas channel is provided in the lower substrate. The gas channel and the fluid channel in the upper substrate have at least one overlapping part in the vertical direction. The elastic film forms a microvalve structure with the ability to adjust the flow resistance of the fluid channel in the upper substrate at the overlapping part. Among them, the droplet close-packed chamber is used to achieve the close arrangement of droplets. The intersection structure of the fluid channel and the oil-phase channel and the microvalve structure together constitute a droplet spacing control unit. The droplet dripping chamber and the capillary tube are used for the formation and derivation of single-droplet dripping.

[0011] The oil-phase channel has a first oil-phase inlet for inputting the oil phase. By changing the flow rate of the oil phase, the spacing between droplets in the fluid channel can be adjusted.

[0012] The gas channel has only one gas-phase inlet for pressurization. By adjusting the magnitude of the applied pressure to cause different blocking effects of the microvalve structure, the flow resistance in the fluid channel of the upper substrate can be changed.

[0013] The single-droplet separation chip cooperates with a contact or non-contact conductivity detection device or a fluorescence detection device to feedback-regulate the gas pressure signal of the gas channel, and can ensure obtaining the expected blocking effect.

[0014] The angle between the fluid channel in the upper substrate and the gas channel in the lower substrate is 0° to 90°, but not equal to 0°.

[0015] The angle between the fluid channel and the oil-phase channel in the upper substrate is 0° to 90°, but not equal to 0°.

[0016] The overlapping part of the gas channel in the lower substrate and the fluid channel in the upper substrate is in a shape that can completely cover the entire width direction of the fluid channel.

[0017] The droplet dripping chamber is also provided with a second oil-phase inlet for supplementing the oil phase, which is used to supplement the amount of oil required for droplet dripping.

[0018] The inlet end of the droplet close-packed chamber can be connected to a droplet generation chip for input of the droplet flow. The outlet end of the capillary tube is connected to a hose, a micro needle, or an inkjet head for output of single-droplet dripping.

[0019] The upper substrate or the lower substrate and the elastic film can be connected by any one of oxygen plasma, hydrogen bonds, chemical bonds, hot pressing, adhesive adhesion, and double-sided tape adhesion after surface modification and pressing.

[0020] In the microfluidic chip, the width of the channel is 10-2000 microns, and the height is 10-300 microns.

[0021] In the microfluidic chip, the overlapping part of the fluid channel of the upper substrate and the gas channel of the lower substrate can be any shape such as square, circular, and oval that can completely cover the width of the fluid channel of the upper substrate by the gas channel of the lower substrate.

[0022] In the microfluidic chip, the liquid or gas inlets and outlets can be in shapes such as circular and square.

[0023] In the microfluidic chip, both the holes and the channels can be processed by microfabrication or machining methods such as reverse molding and imprinting.

[0024] In the microfluidic chip, the upper substrate mentioned above contains at least two liquid inlets and one liquid outlet.

[0025] In the microfluidic chip, both the upper substrate and the lower substrate can be made of any one or more mixed materials, such as silicon, ceramics, glass, and plastics.

[0026] When the single droplet separation is carried out in the present invention, there is at least one microvalve device located behind the confluence node of the droplet fluid and the non-droplet fluid for controlling the flow resistance.

[0027] When designing the flow resistance in front of the confluence node of the droplet flow and the non-droplet flow (oil phase) in the present invention, the appropriate aspect ratio of the channel length and width and the pressurization ratio can be preferably designed so that the change in the pressure difference of the non-droplet flow is more obvious than the change in the droplet flow. Generally, the aspect ratio design should ensure that the flow resistance of the droplet flow channel from the inlet to the confluence node is less than the flow resistance of the non-droplet flow from the inlet to the confluence node. Generally, the pressurization ratio ensures that the greater the pressure of the droplet flow and the smaller the pressure of the non-droplet flow under normal working conditions, the more obvious this effect is.

[0028] In the microfluidic chip, the flow resistance of the structure for supplementing the flow rate should be of appropriate size and match the droplet spacing unit and the external pressure source.

[0029] In the microfluidic chip, a fluid pipeline or other structure should be provided at the rear of the air valve for supplementing the fluid flow required for the droplet to fall.

[0030] The outlet of the microfluidic chip can be connected to a device such as a hose, a micro needle, or an inkjet head that can drop or inject the droplets into the well plate.

[0031] The large chamber of the microfluidic chip should be provided with pillars to prevent it from collapsing when no liquid is injected.

[0032] According to the single droplet separation chip provided by the present invention, it can be functionally divided into three parts: a droplet close-packed unit, a droplet spacing control unit and a droplet dripping unit. 1) The droplet close-packed unit is composed of a droplet close-packed chamber, which is a cavity structure that can realize close arrangement of droplets and has the function of reducing the distance between droplets; 2) The droplet spacing control unit is composed of a droplet flow and an oil phase fluid intersection structure and a microvalve structure for regulating flow resistance. In the intersection structure, the close-packed droplet flow and the oil phase are merged into a pipeline, so that the distance between droplets increases; the microvalve structure can change the flow resistance of the channel to control the droplet flow and the oil phase to flow into the subsequent channel in a certain proportion, so that the droplets pass through the intersection node at equal time intervals; 3) The droplet dripping unit is composed of a droplet dripping chamber and a capillary. The droplet dripping chamber is connected to a constant flow of oil phase, which is used to supplement the amount of oil required for droplet dripping and matches the flow resistance required by the previous droplet spacing control unit; the capillary is used to guide the fluid and form a drop wrapped with droplets at the tube mouth.

[0033] The key invention point of the present invention is that it provides a droplet spacing control unit composed of an intersection structure of a fluid channel and an oil phase channel and a microvalve structure at the intersection of the fluid channel and the gas channel. On the one hand, the flow pressure at the node of the droplet flow and the non-droplet flow is controlled to change the flow rate of the two channels to achieve a fixed ratio. On the other hand, the microvalve structure is used to adjust the flow resistance in the upper substrate, so as to ensure that only a fixed number of equally spaced droplets pass through the intersection node of the droplet flow and the oil phase fluid within a fixed time when the droplet distance is pulled apart, and the oil phase volume required for dripping is supplemented in the rear chamber according to the dripping speed requirement, so as to achieve single droplet encapsulation dripping. The single droplet to be separated can be wrapped in a single cell before separation, so that the system can be used for single cell separation.

[0034] According to the single droplet separation chip provided by the present invention, on the one hand, before establishing a stable fluid state, a large flow rate can be obtained by fully opening the control of the microvalve structure to quickly establish a stable state. On the other hand, after entering the stable state, since the droplet distance control is more sensitive to the external air pressure, and the flow resistance control of the air valve has a lower control effect on the flow and distance than directly applying pressure to the injection port, it is convenient for further precise control. Compared with the microvalve structure in the prior art that switches between the closed and open states to achieve fluid blocking and conduction functions, the single droplet separation chip of the present invention achieves precise flow resistance control function through the microvalve structure, which has significant advantages.

[0035] In summary, the present invention provides a single-droplet separation chip based on a microvalve, which successfully realizes the separation of single cells or droplets, and has the advantages of easy processing, low cost, and simple operation. At the same time, the single-droplet separation chip of the present invention is also easy to integrate with biochemical analysis chips (such as PCR chips). BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 FIG. 1 is a three-dimensional structural schematic diagram of a single-droplet separation chip provided according to a preferred embodiment of the present invention;

[0037] Figure 2 As shown in Figure 1 FIG. 2 is a top-view structural schematic diagram of the single-droplet separation chip shown;

[0038] Figure 3 and Figure 4 FIGS. 3 and 4 are respectively a front-view sectional view and a left-view sectional view of the microvalve structure for flow resistance control when no pressure is applied;

[0039] Figure 5 and Figure 6 FIGS. 5 and 6 are respectively a front-view sectional view and a left-view sectional view of the microvalve structure for flow resistance control after pressure is applied;

[0040] Figure 7 FIG. 7 is an actual effect diagram of the droplet close-packed chamber;

[0041] Figure 8 FIG. 8 is a schematic diagram for controlling the droplet spacing at the intersection node of the droplet flow and the non-droplet flow;

[0042] Figure 9 FIG. 9 is an actual effect diagram for controlling the droplet spacing at the intersection node of the droplet flow and the non-droplet flow;

[0043] Figure 10 FIG. 10 is a detailed enlarged schematic diagram of the droplet dripping chamber and the capillary;

[0044] Figure 11 FIG. 11 is a schematic diagram of the formation of a single droplet dripping at the orifice of the capillary.

[0045] The meanings of the marks in the figures are as follows:

[0046] 1 upper substrate; 2 elastic film; 3 lower substrate; 4 droplet close-packed chamber; 5 fluid channel; 6 droplet dripping chamber; 6a second oil phase inlet; 6b chamber support structure; 7 oil phase channel; 7a first oil phase inlet; 8 capillary; 9 gas channel; 9a gas phase inlet; d droplet; D droplet dripping. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] The present invention will be further described below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0048] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0049] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0050] Combined Figure 1 、 Figure 2 As shown in

[0051] a single-droplet separation chip provided according to a preferred embodiment of the present invention is formed by bonding an upper substrate 1, an elastic film 2, and a lower substrate 3 in sequence from top to bottom.

[0052] Among them, the upper substrate 1 is provided with a droplet close-packed chamber 4, a fluid channel 5, a droplet dripping chamber 6 connected in sequence, an oil-phase channel 7 that intersects with the fluid channel 5, and a capillary 8 connected to the droplet dripping chamber 6. The oil-phase channel 7 has a first oil-phase inlet 7a for inputting the oil phase, and the distance between droplets in the fluid channel 5 can be adjusted by changing the flow rate of the oil phase. Figure 2

[0052]

[0053] According to a single-droplet separation chip provided by the present invention, its working principle is as follows: The droplet close-packed chamber 4 serves as a droplet close-packing unit to achieve the close arrangement of droplets. The confluence structure of the fluid channel 5 and the oil-phase channel 7 and the micro-valve structure at the overlapping part of the fluid channel 5 and the gas channel 9 together provide a droplet spacing control unit. The droplet dripping chamber 6 and the capillary 8 serve as a droplet dripping unit for the formation and derivation of single-droplet dripping. The following is a further detailed description thereof with reference to the accompanying drawings:

[0054] As Figures 3 - 6 shown, it is a schematic diagram of the micro-valve structure in the chip of the present invention under unpressurized and pressurized conditions respectively. When no gas is introduced from the external pressure source of the gas channel 9, as shown in combination with Figures 3 - 4 shown, the elastic membrane 2 is not deformed at this time and maintains its initial horizontal state, without having any influence on the flow resistance in the fluid channel 5; while when gas is introduced from the external pressure source of the gas channel 9 and pressure is applied, as shown in combination with Figures 5 - 6 shown, the elastic membrane 2 is deformed and bulges upward at this time, generating a blockage in the width direction of the fluid channel 5 to regulate the flow resistance in this channel. It should be understood that the degree of deformation of the elastic membrane is regulated by air pressure, and the flow resistance of the fluid channel 5 is related to the degree of deformation of the elastic membrane.

[0055] As Figure 2 shown in, the gas-phase inlet of the gas channel 9 is marked as 9a. Specifically, the output end of the numerical control pressure pump can be directly connected to it with a hose or a connection structure can be designed independently to connect with the Nu'er head.

[0056] As Figure 7 shown, through pre-aggregation and the difference in the flow of fluid and droplets in the droplet close-packed chamber, droplets gather at the inlet to form a close-packed droplet flow, which then flows into the fluid channel 5.

[0057] As Figure 8 and Figure 9 shown, it is a schematic diagram and an actual effect diagram of the confluence structure of the fluid channel 5 and the oil-phase channel 7. It can be seen from the figure that the oil phase is input through the oil-phase pipeline 7 to intersect with the droplet flow and flows into a pipeline, which can widen the droplet spacing so that only a single droplet d passes through the micro-valve structure at its rear end at a fixed time and a fixed distance. Before injecting droplets into the fluid channel 5, the droplet fluid is statically placed and other treatments are performed to make the droplets gather closely in the droplet close-packed chamber. After injecting the droplets, by controlling means such as the flow rate in the oil-phase pipeline and the fluid ratio of the two channels, the droplet flow can be made to almost stop and then release droplets at a fixed time.

[0058] As Figure 10As shown in the figure, it is a detailed enlarged schematic diagram of the liquid droplet dripping chamber 6 and the capillary 8. The liquid droplet dripping chamber 6 is provided with a second oil phase inlet 6a for supplementing the oil phase to supply the amount of oil required for liquid droplet dripping. The liquid droplet dripping chamber 6 is also provided with a plurality of chamber support structures 6b to prevent the cavity from collapsing when no liquid is injected. Among them, the liquid droplet dripping chamber 6 and the capillary 8 are respectively used for the formation and derivation of individual liquid droplets. The liquid droplets adjusted by the droplet interval control unit are discharged into the liquid droplet dripping chamber 6 from the fluid channel at equal intervals and equal times. There is a large flow rate in the chamber to meet the requirements of the liquid droplet dripping for the dripping volume. Then, the liquid droplets entering the liquid droplet dripping chamber 6 are discharged into the capillary 8 along with the fluid in the chamber, and then drip outside the chip.

[0059] As Figure 11 shown, when the fluid in the chip passes through the orifice of the capillary 8 during dripping, the small droplets d in the fluid are wrapped. The function of having only one droplet in a fixed flow rate has been realized inside the chip. Therefore, according to the chip provided by the present invention, it can be ensured that there is only one small droplet d in each liquid droplet dripping D, thus successfully realizing the separation of single droplets in the fluid.

[0060] According to a preferred embodiment of the present invention, the inlet end of the droplet close-packed chamber 4 can be connected to a droplet generation chip (which belongs to the prior art) for the input of the droplet flow, and the outlet end of the capillary 8 can be connected to a hose, a micro needle or an inkjet head for the output of single droplet dripping.

[0061] According to a preferred embodiment of the present invention, in the case where the droplet channel in the single droplet separation structure of the system is regulated by almost shutting off the droplet flow and then releasing it, it can be achieved by using a pulsed wave for pressurization. Since the droplets are pretreated during injection, under the action of an appropriate pulsed pressure, one or more droplets can be released through the intersection node when the pressure of each pulse is withdrawn, and separated by subsequent devices.

[0062] According to a preferred embodiment of the present invention, when using the droplet spacing control unit to control the droplet spacing, it can be combined with detection methods such as contact or non-contact conductance detection and fluorescence detection for cooperation, and feedback regulation is performed on the air valve pressure signal to ensure that the expected control effect can be obtained.

[0063] For such a single droplet separation chip provided by the above preferred embodiment, its operation process is described as follows:

[0064] 1) A large number of droplets are input into the chamber through the inlet of the droplet close-packed chamber 4, and the droplets are closely packed in it to form closely packed droplets and flow into the fluid channel 5;

[0065] 2) Input the oil phase into the oil phase channel 7 through the first oil phase inlet 7a, and adjust the spacing between the droplets in the fluid channel 5 by changing the flow rate of the oil phase, so that a relatively large spacing is maintained between adjacent droplets;

[0066] 3) By changing the pressure in the gas channel 9, change the flow resistance in the fluid channel 5 of the upper substrate 1, and ensure that the droplets are discharged from the fluid channel 5 into the droplet dripping chamber 6 at equal intervals and equal times;

[0067] 4) The output flow rate control of the large flow chamber enables the speed of the droplets entering the chamber to match the speed of the droplet dripping, ensuring that there is exactly one small droplet d in each large droplet D flowing out from the end of the capillary 8, thereby finally realizing single droplet separation.

[0068] Embodiment

[0069] According to this preferred embodiment, a single droplet separation chip as shown in Figure 1 is provided. The pipe size design of the combined part with the capillary has a width and height slightly smaller than the capillary size, and the height of the remaining pipe sizes is approximately equal to the droplet size, and the width is 1-2 times the droplet size.

[0070] Specifically, this embodiment is applicable to droplets with a diameter of 40 microns and a capillary with an inner diameter of 300 microns and a wall thickness of 100 microns. The height of the two-layer chip at the combined part with the capillary is about 230 microns, and the width is 400 microns. The remaining pipes are designed with a height of 40 microns and a width of 50-70 microns. Before droplet injection, first introduce the oil phase to discharge the gas in all channels except the gas channel, and then apply a pressure of 30-150 mbar from the droplet injection inlet to adjust the microvalve and the side oil phase pressure so that a single droplet enters the chamber at a fixed time, and this time should be consistent with the time interval of the droplet dripping at the capillary orifice. This interval can be regulated by designing the capillary size, the port shape, and the output flow rate of the large flow chamber. Thus, droplets reach the capillary orifice at a fixed time interval and are wrapped by the oil phase and separated by dripping.

[0071] The above-mentioned is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. The above embodiments of the present invention can also make various changes. All simple, equivalent changes and modifications made according to the claims and the content of the specification of the present invention application fall within the scope of the claims of the present invention patent. Those not described in detail in the present invention are all conventional technical contents.

Claims

1. A single droplet separation chip controlled by a microvalve structure, characterized in that, The single-droplet separation chip is formed by bonding an upper substrate, an elastic film, and a lower substrate in sequence from top to bottom; The upper substrate is provided with a droplet close-packed chamber, a fluid channel, a droplet dripping chamber connected in sequence, an oil-phase channel forming an intersection structure with the fluid channel, and a capillary tube connected to the droplet dripping chamber; The lower substrate is provided with a gas channel, which has at least one overlapping part with the fluid channel in the upper substrate in the vertical direction, and the elastic film forms a micro-valve structure with the ability to adjust the flow resistance in the fluid channel in the upper substrate at the overlapping part; Among them, the droplet close-packed chamber is used to realize the close arrangement of droplets, and the intersection structure of the fluid channel and the oil-phase channel and the micro-valve structure together constitute a droplet spacing control unit, and the droplet dripping chamber and the capillary tube are used for the formation and derivation of single-droplet dripping.

2. The single droplet separation chip according to claim 1, characterized in that, The oil-phase channel has a first oil-phase inlet for inputting the oil phase, and the distance between adjacent droplets in the fluid channel can be adjusted by changing the flow rate of the oil phase.

3. The single droplet separation chip according to claim 1, characterized in that, The gas channel has only one gas-phase inlet for pressurization, and by adjusting the magnitude of the applied pressure to make the micro-valve structure produce different blocking effects, the flow resistance in the fluid channel of the upper substrate can be changed.

4. The single droplet separation chip according to claim 3, characterized in that, The single-droplet separation chip cooperates with a contact or non-contact conductivity detection device, or a fluorescence detection device to feedback-regulate the gas pressure signal of the gas channel to ensure obtaining the expected blocking effect.

5. The single droplet separation chip according to claim 1, characterized in that, The angle between the fluid channel in the upper substrate and the gas channel in the lower substrate is 0° to 90°, but not equal to 0°.

6. The single droplet separation chip according to claim 1, characterized in that, The angle between the fluid channel and the oil-phase channel in the upper substrate is 0° to 90°, but not equal to 0°.

7. The single droplet separation chip according to claim 1, characterized in that, The overlapping part of the gas channel in the lower substrate and the fluid channel in the upper substrate is in a shape that can completely cover the entire width direction of the fluid channel.

8. The single droplet separation chip according to claim 1, characterized in that, The droplet dripping chamber is also provided with a second oil-phase inlet for supplementing the oil phase to supplement the amount of oil required for droplet dripping.

9. The single droplet separation chip according to claim 1, characterized in that, The inlet end of the droplet close-packed chamber can be connected to a droplet generation chip for input of droplet flow, and the outlet end of the capillary tube is connected to a hose, a micro-needle or an inkjet head for output of single-droplet dripping.

10. The single droplet separation chip according to claim 1, characterized in that, The upper substrate or the lower substrate and the elastic film are connected by any one of oxygen plasma, hydrogen bond, chemical bond, hot pressing, adhesive adhesion, and double-sided tape bonding after surface modification and pressing.

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