Pneumatic microfluidic chip for quantitatively mixing microliter scale liquids and working method thereof

Abstract

The application provides a pneumatic microfluidic chip for quantitatively mixing microliter liquid and a working method, wherein a pneumatic chamber is arranged at a corresponding position of a cover layer, a liquid inlet mixing layer and a pneumatic mixing layer, liquid in a sample storage pool on the pneumatic mixing layer is pressurized by the pneumatic chamber to flow through a reagent storage pool on the liquid inlet mixing layer into a mixing channel for mixing, the volume of the reagent storage pool and the sample storage pool can realize quantitative loading and mixing of the liquid sample and the reagent, and the pneumatic pressing mode can make the liquid sample and the reagent fully mixed in the mixing channel and accelerate the mixing speed of the liquid sample and the reagent.

Description

Technical Field

[0001] This invention belongs to the field of microfluidic chip technology, and particularly relates to a pneumatic microfluidic chip and its working method for quantitative mixing of micro-level liquids. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In the fields of chemistry, pharmaceuticals, and food, the analysis and detection of samples often require the mixing of two or more liquids in specific proportions to prepare a particular liquid phase mixture. Especially in the detection of biological components such as proteins or DNA, and in drug development, frequent quantitative mixing of samples and reagents is necessary, and the accuracy of the mixing ratios of different components is typically critical. However, traditional mixing steps are generally performed manually or by relay-based control systems. These methods often fail to meet the required precision for specific liquid phase mixtures due to slow reaction times, inaccurate sample measurement, and uneven mixing. Furthermore, traditional mixture analysis requires large quantities of mixed samples and is prone to contamination, leading to unsatisfactory analytical results. Therefore, there is an urgent need for more reliable and automated emerging technologies and methods for the accurate quantitative mixing of liquid samples and reagents.

[0004] Microfluidics refers to the active and passive manipulation of micro- and nano-liter fluids characterized by laminar or low Reynolds number flow, aiming to analyze fluid properties at the microscale. It integrates a series of operations such as preparation, collection, transport, separation, metering, mixing, dilution, reaction, and detection onto a microfluidic chip of a few square centimeters or smaller. By reducing the characteristic size of the fluid system and the amount of reagent used, microfluidics and related devices can effectively reduce reaction time, improve mass transfer rate, increase mixing accuracy, and enhance system reliability. Currently, this technology has been widely applied in fields such as biochemical analysis, point-of-care diagnostics, drug research, genetic engineering, material screening and synthesis, environmental monitoring and protection, health quarantine, and forensic identification. How to utilize microfluidics to solve the problems of uneven mixing, inaccurate mixing ratios, high sample consumption, and slow mixing rates in traditional liquid sample mixing techniques is a pressing issue that needs to be addressed. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention provides a pneumatic microfluidic chip and its working method for quantitative mixing of micro-level liquids. The setting of the volume of the reagent reservoir and the sample reservoir can realize the quantitative loading and mixing of liquid samples and reagents. The pneumatic pressing method can make the liquid samples and reagents fully mixed in the mixing channel, thereby accelerating the mixing speed of liquid samples and reagents.

[0006] To achieve the above objectives, a first aspect of the present invention provides a pneumatic microfluidic chip for quantitative mixing of micro-level liquids, comprising: a substrate layer, a pneumatic mixing layer, a liquid inlet mixing layer, and a capping layer disposed sequentially.

[0007] A liquid sample loading inlet and a reagent loading inlet are provided on the cover layer. The liquid sample loading inlet and the reagent loading inlet are respectively connected to the sample storage tank on the pneumatic mixing layer and the reagent storage tank on the liquid inlet mixing layer.

[0008] An inclined mixing channel is provided on the liquid inlet mixing layer, and the inclined mixing channel is connected to a horizontal mixing channel provided at a corresponding position in the pneumatic mixing layer to form a mixing channel;

[0009] Pneumatic chambers are provided at corresponding positions of the cover layer, liquid inlet mixing layer, and pneumatic mixing layer. By squeezing the pneumatic chambers, the liquid in the sample storage pool flows through the reagent storage pool and enters the mixing channel for mixing.

[0010] A second aspect of the present invention provides a method of operating a pneumatic microfluidic chip for quantitative mixing of microliter liquids, comprising:

[0011] Liquid samples are injected into the sample storage tank through the liquid sample loading inlet, and reagents are injected into the reagent storage tank through the reagent loading inlet.

[0012] By pressurizing the pneumatic chamber, the liquid sample in the sample reservoir is pneumatically loaded, causing the liquid sample to flow into the mixing channel through the reagent reservoir.

[0013] The above one or more technical solutions have the following beneficial effects:

[0014] In this invention, pneumatic chambers are provided at corresponding positions in the covering layer, the liquid inlet mixing layer, and the pneumatic mixing layer. The pneumatic chambers pneumatically pressurize the sample storage pool on the pneumatic mixing layer, causing the liquid in the sample storage pool to flow through the reagent storage pool on the liquid inlet mixing layer and enter the mixing channel for mixing. The volume settings of the reagent storage pool and the sample storage pool enable quantitative loading and mixing of liquid samples and reagents. The pneumatic pressing method allows the liquid samples and reagents to be fully mixed in the mixing channel, accelerating the mixing speed of liquid samples and reagents.

[0015] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0017] Figure 1 This is an exploded view of the pneumatic microfluidic chip in Embodiment 1 of the present invention;

[0018] Figure 2 This is a schematic diagram of the pneumatic microfluidic chip assembly in Embodiment 1 of the present invention.

[0019] In the picture:

[0020] 1. Covering layer, 2. Liquid mixing layer, 3. Pneumatic mixing layer, 4. Substrate layer, 5. Positioning guide hole, 6. Pneumatic chamber, 7. Chamber sealing ring, 8. Rubber film, 9. Liquid sample loading inlet, 10. Reagent loading inlet, 11. Liquid sample loading channel, 12. Reagent loading channel, 13. Vent, 14. Reagent reservoir, 15. Mixing inlet channel, 16. Mixing outlet channel, 17. Inclined mixing channel, 18. Horizontal mixing channel, 19. Solution detection chamber, 20. Pressure channel, 21. Sample reservoir, 22. Mixing channel. Detailed Implementation

[0021] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0023] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0024] Example 1

[0025] like Figures 1-2 As shown, this embodiment discloses a pneumatic microfluidic chip for quantitative mixing of micro-level liquids, comprising: a substrate layer 4, a pneumatic mixing layer 3, a liquid inlet mixing layer 2, and a capping layer 1 arranged sequentially;

[0026] A liquid sample loading inlet 9 and a reagent loading inlet 10 are provided on the cover layer 1. The liquid sample loading inlet 9 and the reagent loading inlet 10 are respectively connected to the sample storage tank 21 of a set size on the pneumatic mixing layer 3 and the reagent storage tank 14 of a set size on the liquid mixing layer 2.

[0027] An inclined mixing channel 17 is provided on the liquid inlet mixing layer 2. The inclined mixing channel 17 is connected to the horizontal mixing channel 18 provided at the corresponding position of the pneumatic mixing layer 3 to form a mixing channel 22.

[0028] Pneumatic chambers 6 are provided at corresponding positions of the cover layer 1, the liquid inlet mixing layer 2, and the pneumatic mixing layer 3. The sample storage tank 21 is pressurized by the external power component squeezing the pneumatic chambers 6, so that the liquid in the sample storage tank 21 flows through the reagent storage tank 14 and enters the mixing channel for mixing.

[0029] In this embodiment, the four main structures—substrate layer 4, pneumatic mixing layer 3, liquid mixing layer 2, and cover layer 1—together with the pneumatic chamber 6 pressed by an external crank component, constitute a complete microfluidic chip.

[0030] Specifically, positioning guide holes 5 are designed on the edges of the substrate layer 4, the aerodynamic mixing layer 3, the liquid inlet mixing layer 2 and the cover layer 1, so that each layer can be correctly aligned and assembled.

[0031] Optionally, in this embodiment, the cover layer 1 and the substrate layer 4 are made of PC material, and the pneumatic mixing layer 3 and the liquid mixing layer 2 are made of PMMA material.

[0032] A pneumatic chamber 6 is provided on one side of the pneumatic mixing layer 3, the liquid mixing layer 2 and the covering layer 1, and is bonded to the rubber film 8 by the chamber sealing ring 7.

[0033] A liquid sample loading inlet 9 and a reagent loading inlet 10 are designed on the cover layer 1. After the layers are assembled, the liquid sample loading inlet 9 and the reagent loading inlet 10 are connected to the inlet ends of the liquid sample loading channel 11 and the reagent loading channel 12, respectively. The diameter of the liquid sample loading inlet 9 is larger than the width of the liquid sample loading channel 11, and the diameter of the reagent loading inlet 10 is smaller than the width of the reagent loading channel 12. After the liquid sample is loaded, it is mainly located in the sample reservoir 21. The diameter of the liquid sample loading inlet 9 is larger than the width of the liquid sample loading channel 11 to facilitate the loading of the liquid sample. After the reagent is loaded, it is mainly located in the reagent reservoir 14 and the reagent loading channel 12. The diameter of the reagent loading inlet 10 is smaller than the width of the reagent loading channel 12 to generate sufficient capillary resistance to prevent the reagent from flowing out after loading.

[0034] The cover layer 1 is designed with vent holes 13, which are connected to the solution detection chamber 19 set on the liquid mixing layer 2 after the assembly of each layer is completed, so as to balance the pressure.

[0035] A mixing inlet channel 15, a mixing outlet channel 16, and an oblique mixing channel 17 are designed on the axis of symmetry along the length of the liquid mixing layer 2. After the assembly of each layer, the oblique mixing channel 17 is connected to the horizontal mixing channel 18 on the pneumatic mixing layer 3 to form a 22 mixing channel.

[0036] A solution detection chamber 19 is designed on the liquid inlet mixing layer 2 and is connected to the mixing channel 22 through the mixing outlet channel 16. After the assembly of each layer is completed, the pressure is balanced through the vent hole 13 on the cover layer 1.

[0037] The liquid mixing layer 2 is provided with a liquid sample loading channel 11 and a reagent loading channel 12, and a reagent storage tank 14 is provided at the outlet of the reagent loading channel 12.

[0038] The pneumatic mixing layer 3 has a pressure channel 20 on one side of the pneumatic chamber 6. The pressure channel 20 is connected to the sample storage tank 21 and is pneumatically loaded by squeezing the gas in the pneumatic chamber 6 into the sample storage tank 21. A horizontal mixing channel 18 is designed at the corresponding position to the inclined mixing channel 17 in the liquid inlet mixing layer 2. The inclined mixing channel 17 and the horizontal mixing channel 18 are connected by a connecting hole, the diameter of which is larger than the width of the mixing channel 22. Since the horizontal mixing channel 18 and the inclined mixing channel 17 are located in different layers, when the liquid flows alternately between the two mixing channels, if the diameter of the connecting pipe is smaller than the width of the mixing channel, the corresponding capillary resistance will be relatively large, hindering the flow and mixing of the liquid. The diameter of the connecting hole is larger than the width of the mixing channel to reduce the flow and mixing resistance between the two layers, so that the pneumatic pressure required for the liquid sample and reagent to mix during the flow process corresponds to the effective volume calculated by the pneumatic chamber.

[0039] Optionally, the pressure channel 20 and the liquid sample loading channel 11 on the liquid mixing layer 2 can both enter the sample storage tank 21 through the same through hole. Pneumatic loading is only used to supply pressure for mixing the liquid sample and reagent after loading.

[0040] Specifically, the outlet of the sample storage tank 21 is located at the inlet of the mixing channel.

[0041] Among them, there are multiple oblique mixing channels 17 arranged in parallel, and multiple horizontal mixing channels 18 arranged in parallel. The oblique mixing channels 17 and the horizontal mixing channels 18 have a certain angle. Each horizontal mixing channel 18 is connected to the oblique mixing channel 17 in sequence, and the mixing inlet channel 15 is connected to the first horizontal mixing channel 18.

[0042] In this embodiment, the liquid storage volumes of the sample storage tank 21 and the reagent storage tank 14 are set to achieve quantitative loading and mixing of liquid samples and reagents.

[0043] In this embodiment, the volume of the sample reservoir is approximately 90 μl, and the volume of the reagent reservoir is approximately 7 μl. The required amount of reagents and liquid samples to be mixed is significantly reduced compared to traditional mixing methods.

[0044] Example 2

[0045] The purpose of this embodiment is to provide a working method for a pneumatic microfluidic chip for quantitative mixing of micro-level liquids, using the pneumatic microfluidic chip for quantitative mixing of micro-level liquids from Embodiment 1, including:

[0046] Liquid samples are injected into the sample storage tank through the liquid sample loading inlet, and reagents are injected into the reagent storage tank through the reagent loading inlet.

[0047] By pressurizing the pneumatic chamber, the liquid sample in the sample reservoir is pneumatically loaded, causing the liquid sample to flow into the mixing channel through the reagent reservoir.

[0048] Specifically, initially, the vent 13 is connected to the atmosphere. The liquid sample is pipetted into the liquid sample loading inlet 9, flows through the liquid sample loading channel 11 into the sample reservoir 21, until the entire sample reservoir 21 is filled (the sample front reaches the sample reservoir outlet). The loading process should be slow to avoid air bubble formation. After liquid sample loading is complete, the liquid sample loading inlet 9 is sealed with a rubber diaphragm. Using a 10μL pipette, the reagent is pipetted into the reagent loading inlet 10, flows through the reagent loading channel 12 into the reagent reservoir 14. The loading process should be slow to avoid air bubble formation. After reagent loading is complete, the reagent loading inlet 10 is sealed with a rubber diaphragm.

[0049] Adjusting the position of the external crank component presses the plunger, causing it to press against the rubber diaphragm 8 until the liquid sample loaded in the sample reservoir 21 begins to form a gas-liquid interface. Activating the external crank component lowers the plunger, pressing the rubber diaphragm 8, thus compressing the gas in the pneumatic chamber 6 to achieve a pneumatic loading effect on the liquid sample in the sample reservoir 21. The liquid sample flows from the sample reservoir 21 through the reagent reservoir 14 and enters the mixing channel 22 through the mixing inlet channel 15. By manipulating the pressing component, the liquid mixture flows back and forth in the mixing channel 22 between the mixing inlet channel 15 and the mixing outlet channel 16, ensuring thorough mixing of the liquid sample and reagent. After thorough mixing, the external crank component presses the rubber diaphragm 8 until all the thoroughly mixed liquid mixture is loaded into the solution detection chamber 19 for detection and analysis. By setting the effective volume of the pneumatic chamber (185 μl), all the liquid in the sample reservoir 21 and reagent reservoir 14 can be pressed into the mixing channel 22.

[0050] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A pneumatic microfluidic chip for quantitative mixing of microliter liquids, characterized in that, include: The substrate layer, the aerodynamic mixing layer, the liquid inlet mixing layer, and the cover layer are arranged sequentially. A liquid sample loading inlet and a reagent loading inlet are provided on the cover layer. The liquid sample loading inlet and the reagent loading inlet are respectively connected to a sample storage tank of a set size on the pneumatic mixing layer and a reagent storage tank of a set size on the liquid mixing layer. An inclined mixing channel and a mixing inlet channel are provided on the liquid inlet mixing layer. The inclined mixing channel is connected to a horizontal mixing channel provided at a corresponding position in the pneumatic mixing layer to form a mixing channel. There are multiple oblique mixing channels arranged in parallel, and multiple horizontal mixing channels arranged in parallel. The oblique mixing channels and the horizontal mixing channels have an angle between them. Each horizontal mixing channel is connected to the oblique mixing channel in sequence, and the mixing inlet channel is connected to the first horizontal mixing channel. Pneumatic chambers are provided at corresponding positions of the cover layer, liquid inlet mixing layer, and pneumatic mixing layer. By squeezing the pneumatic chambers, the liquid in the sample storage pool flows through the reagent storage pool and enters the mixing channel for mixing.

2. The pneumatic microfluidic chip for quantitative mixing of micro-level liquids as described in claim 1, characterized in that, A liquid sample loading channel is provided on the liquid mixing layer, and the liquid sample loading inlet is connected to the sample storage tank through the liquid sample loading channel. A reagent loading channel is provided on the liquid mixing layer, and the reagent loading inlet is connected to the reagent storage tank through the reagent loading channel.

3. The pneumatic microfluidic chip for quantitative mixing of micro-level liquids as described in claim 1, characterized in that, A vent is provided on the cover layer, and the vent communicates with the solution detection chamber provided on the liquid mixing layer.

4. The pneumatic microfluidic chip for quantitative mixing of microliter liquids as described in claim 1, characterized in that, A mixing inlet channel and a mixing outlet channel are provided along the length direction on the liquid mixing layer; the mixing inlet channel and the mixing outlet channel are respectively connected to the mixing channel.

5. The pneumatic microfluidic chip for quantitative mixing of micro-level liquids as described in claim 3, characterized in that, The solution detection chamber is connected to the mixing channel.

6. The pneumatic microfluidic chip for quantitative mixing of micro-level liquids as described in claim 1, characterized in that, A pressure channel is provided on the pneumatic mixing layer, and the pressure channel is connected to the pneumatic chamber.

7. The pneumatic microfluidic chip for quantitative mixing of micro-level liquids as described in claim 1, characterized in that, It also includes a chamber sealing ring and a rubber film, which are bonded to the pneumatic chamber.

8. The pneumatic microfluidic chip for quantitative mixing of micro-level liquids as described in claim 1, characterized in that, The oblique mixing channel and the horizontal mixing channel are connected by a connecting hole, the diameter of which is greater than the width of the oblique mixing channel / horizontal mixing channel.

9. The pneumatic microfluidic chip for quantitative mixing of micro-level liquids as described in claim 6, characterized in that, The diameter of the liquid sample loading inlet is greater than the width of the liquid sample loading channel; the width of the pressure channel is less than the width of the liquid sample loading channel.

10. A method of operating a pneumatic microfluidic chip for quantitative mixing of micro-level liquids according to any one of claims 1-9, characterized in that, include: Liquid samples are injected into the sample storage tank through the liquid sample loading inlet, and reagents are injected into the reagent storage tank through the reagent loading inlet. By pressurizing the pneumatic chamber, the liquid sample in the sample reservoir is pneumatically loaded, causing the liquid sample to flow into the mixing channel through the reagent reservoir.

Images