CN221816171U - A self-flowing pump-free microfluidic chip based on capillary action - Google Patents

Abstract

The utility model discloses a self-flowing pump-free microfluidic chip based on capillary action, and relates to the technical field of microfluidic chips. The microfluidic chip is provided with an integrally formed glass substrate, a lower PDMS sheet and an upper PDMS sheet from bottom to top, and the upper PDMS sheet includes: a sample addition hole; a detection chamber: connected to the sample addition hole, used to detect the sample to be tested; a driving chamber: connected to the other end of the detection chamber, wherein a capillary channel of an array structure is arranged, which acts as a capillary pump to drive the sample to be tested to flow through the channel; a drainage chamber: connected to the driving chamber, guiding the sample to be tested to flow out of the driving chamber; a waste liquid port: connected to the drainage chamber, used to discharge liquid waste. The utility model can improve the siphon force of the microchannel, so that the liquid automatically flows along the designed channel direction, has the advantages of sensitive, repeatable and spatially limited detection, and instant testing, and can become an effective diagnostic tool for rapid and accurate detection of biomarkers.

Description

A self-flowing pump-free microfluidic chip based on capillary action

Technical Field

The utility model relates to the technical field of microfluidic chips, in particular to a self-flowing pump-free microfluidic chip based on capillary action.

Background Art

Microfluidic chip, also known as Lab-on-a-Chip, is a miniaturized experimental platform that integrates microfluidic channels, micro-reaction chambers and other micro-components. This technology reduces the laboratory-scale analysis process to the μm level, the ability to process in a short analysis time (min or s), automation, easy integration or multiplexing and high-throughput analysis, and achieves a high degree of integration of multiple steps such as sample processing, separation, and detection.

With the development of micro-electromechanical systems (MEMS) and flexible electronics, biosensors for molecular diagnostics tend to be combined with miniaturized and highly integrated platforms to meet the application of point-of-care testing (POCT). These platforms usually include microfluidics, lateral flow analysis (LFA) and capillary platforms. Microfluidics, or lab on a chip, is a technology that operates and processes fluids of tens of microns in size to achieve chemical or biological needs. Microfluidic platforms are usually composed of multiple elements such as micro-millimeter to sub-millimeter fluid channels, reaction or detection chambers, filters and sensor units, and are usually manufactured based on microfabrication technologies such as soft lithography on silicon, metal, polymer and glass substrates. A series of functions such as the introduction, purification, separation, fluid movement and reaction of samples and reagents are concentrated on a miniaturized chip.

Microfluidic chips have become one of the research hotspots in recent years due to their small size, easy operation, low cost, and low sample consumption. At present, it has become a promising alternative method for immunoassays, and the demand for diagnostic technology is growing. It can provide high-quality equipment for accurate detection of various diseases and cancers. Usually, microfluidic chips are composed of microchannels, microvalves, micropumps, and detection modules. These modules can be combined and designed according to actual needs to meet the needs of different application scenarios. The preparation methods of microfluidic chips include photolithography, soft engraving, 3D printing, etc., and the appropriate preparation method can be selected according to actual needs. In the biomedical field, microfluidic chips are widely used in cell culture, gene detection, protein analysis, pathogen detection, etc. With the help of microfluidic chip technology, high-sensitivity and high-specificity detection of low-abundance biological samples can be achieved, which provides strong support for portable real-time detection of diseases.

However, the microfluidic chip in the prior art still needs to rely on external force to control the flow of samples during the sample testing process, which is inconvenient to operate.

Utility Model Content

The utility model provides a capillary-based self-flowing pump-free microfluidic chip, aiming to solve the problems existing in the above-mentioned background technology.

In order to achieve the above technical objectives, the utility model mainly adopts the following technical solutions:

A capillary-based self-flowing pump-free microfluidic chip is provided with an integrally formed glass substrate, a lower PDMS sheet and an upper PDMS sheet from bottom to top, wherein the upper PDMS sheet comprises:

Sample addition hole: used to add the sample to be tested;

Detection chamber: connected to the sample adding hole through a capillary tube, used for detecting the sample to be tested;

A driving chamber is connected to the other end of the detection chamber and is provided with a capillary channel of an array structure, which acts as a capillary pump to drive the sample to be tested to flow through the channel;

Drainage chamber: connected to the driving chamber, guiding the sample to be tested to flow out of the driving chamber;

Waste liquid outlet: connected to the drainage chamber through a capillary channel, used to discharge liquid waste.

In a preferred embodiment of the present invention, the number of the detection chambers is two, each of which is composed of a plurality of circular chambers connected in series, and cylinders are arranged in an array in the circular chambers.

Furthermore, the capillary channel is a Y-shaped capillary channel.

In a preferred embodiment of the present invention, the driving chamber is configured as a rectangular structure, the drainage chamber is configured as a triangular structure, and the triangular bottom of the drainage chamber is collinearly arranged with the top of the driving chamber.

Furthermore, the drainage chamber is also provided with capillary channels in an array structure.

In a preferred embodiment of the present invention, the lower PDMS sheet is further provided with two strip-shaped concave surfaces, and a gold-plated silicon sheet is mounted in the strip-shaped concave surfaces.

Compared with the prior art, the utility model has the following beneficial effects:

The capillary-based self-flowing pump-free microfluidic chip provided by the utility model integrates aptamers to capture targets, and can make liquids flow automatically. A specially designed microfluidic channel is used to improve the siphon force of the microchannel, and the mixed solution of the immune response is injected into the sample addition hole. Through the hydrophilic treatment in the microchannel, the mixed solution automatically flows along the designed channel direction. The combination with microfluidics provides ideal conditions for realizing sensitive, repeatable and spatially limited detection and point-of-care testing (POCT), and can become a fast, accurate and effective diagnostic tool for detecting biomarkers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of the microfluidic chip assembly provided by the present invention;

FIG. 2 is a top view of FIG. 1 .

DETAILED DESCRIPTION

The technical scheme of the present invention is further described in detail below through specific examples in conjunction with the accompanying drawings. The raw materials required in the examples can be purchased from the market or synthesized using known methods.

Example 1

As shown in FIG1 , a capillary-based self-flowing pump-free microfluidic chip is provided with an integrally formed glass substrate 1, a lower PDMS sheet 2 and an upper PDMS sheet 3 from bottom to top, wherein the upper PDMS sheet 3 includes:

Sample addition hole 5: used to add the sample to be tested; its length is about 3mm.

Detection chamber 6: connected to the sample adding hole 5 through a capillary tube 7, used for detecting the sample to be tested;

The detection chamber is set to 2, each detection chamber 6 is composed of a plurality of circular chambers connected in series, and cylinders are arranged in an array in the circular chamber. Each cylinder has a diameter of 100 μm and a height of 100 μm. In the present utility model, preferably 3 circular chambers are connected in series, respectively distributed on both sides of the sample addition hole.

The array of cylinders has two functions. One is to provide support to prevent the chamber from collapsing (because it is a soft PDMS structure, the unsupported part is prone to collapse). The second is to provide drainage. This microstructure can generate capillary force to guide the liquid to flow along the direction of the microfluidic channel.

In the utility model, the capillary channel 7 is correspondingly configured as a Y-shaped capillary channel, and the two branches of the Y-shaped capillary channel are respectively connected to the circular chambers arranged on both sides of the sample addition hole 5, so that the sample to be tested flows from the Y-shaped capillary channel to the detection chambers 6 on both sides, which is convenient for separate detection and improves the detection effect.

The driving chamber 8 is connected to the other end of the detection chamber 6, and is provided with an array-shaped capillary channel 9, which acts as a capillary pump to drive the sample to be tested to flow through the channel. When the liquid sample to be tested contacts the capillary channel 9, it can fully guide the movement of the fluid.

The drainage chamber 10 is connected to the driving chamber 8 and guides the sample to be tested to flow out of the driving chamber 8 .

In the present invention, the driving chamber 8 is set to a rectangular structure, the drainage chamber 9 is set to a triangular structure, and the triangular bottom of the drainage chamber 9 is arranged in a collinear manner with the top of the driving chamber 8. That is, the two sides of the triangular drainage chamber 10 form a diversion path, so that the liquid flowing through the driving chamber 8 enters the waste liquid port 11 under the action of the drainage chamber 10.

Waste liquid outlet 11: connected to the drainage chamber 10 through a capillary channel, used to discharge liquid waste. The capillary channel is also set as a Y-shaped capillary channel, where the two branches of the Y-shaped capillary channel are respectively connected to the drainage chamber 10 on both sides, so that the waste liquid enters the waste liquid outlet under the capillary action and is discharged.

In addition, in the present invention, two shaped concave surfaces are arranged on the lower PDMS sheet 2, and the gold-plated silicon sheets 4 are mounted in the two shaped concave surfaces.

How to use the microfluidic chip:

(1) Prepare the required materials and equipment, including multiple syringe pumps, connecting pipes, hoses, microfluidic chips, and the required liquid samples and oil phases to be tested.

(2) Connect the connecting pipes to the outlets of the injection pumps respectively, and ensure that the connection between the pipes and the injection pumps is tight and leak-free.

(3) Insert the other end of the hose into the corresponding injection hole to deliver the liquid to the microfluidic chip during the experiment.

(4) Set the appropriate flow rate for each syringe pump according to the experimental requirements. Ensure that the flow rate of the syringe pump can meet the experimental requirements so that the liquid can be accurately delivered during the experiment.

(5) Turn on the syringe pump to deliver the liquid sample to be tested and the oil phase to the injection hole of the microfluidic chip respectively.

(6) Under the continuous action of the oil phase, the liquid sample is divided into several tiny droplets in the microfluidic chip. Each droplet can be regarded as an independent micro-reaction system.

(7) As the droplets flow in the channels of the microfluidic chip, the liquid in the droplets is quickly mixed and evenly mixed. By controlling the flow rate of the syringe pump and the pressure of the oil phase, the size and shape of the droplets can be adjusted to achieve different experimental purposes.

The microfluidic chip for generating continuous concentration gradients and outputting independent concentrations provided in the embodiments of the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims (6)

1. The utility model provides a from flowing to exempt from micro-fluidic chip of pump based on capillary, is provided with integrated into one piece's glass substrate, lower floor's PDMS piece and upper PDMS piece from bottom to top, its characterized in that, upper PDMS piece includes:

Sample addition well: for adding a sample to be tested;

Detection chamber: the sample feeding device is connected with the sample feeding hole through a capillary channel and is used for detecting a sample to be detected;

Driving the chamber: the capillary channel is communicated with the other end of the detection chamber, and an array-shaped structure is arranged in the capillary channel and is used as a capillary pump to drive the sample to be detected to flow through the channel;

drainage chamber: the device is communicated with the driving chamber and guides the sample to be tested to flow out of the driving chamber;

Waste liquid port: is communicated with the drainage chamber through a capillary channel and is used for discharging liquid waste.

2. The capillary-based self-priming microfluidic chip according to claim 1, wherein the number of detection chambers is 2, each detection chamber is formed by connecting a plurality of circular chambers in series, and cylinders are arranged in an array in the circular chambers.

3. The capillary-based self-priming microfluidic chip according to claim 2, wherein said capillary channel is a Y-capillary channel.

4. The capillary-based self-priming microfluidic chip according to claim 1, wherein said drive chamber is arranged in a rectangular configuration, said drainage chamber is arranged in a triangular configuration, and the triangular bottom of the drainage chamber is arranged co-linear with the top of said drive chamber.

5. The capillary-based self-priming microfluidic chip according to claim 4, wherein the drainage chamber is also internally provided with capillary channels in an array-like structure.

6. The capillary-based self-priming microfluidic chip according to claim 1, wherein two strip-shaped concave surfaces are further arranged on the lower PDMS sheet, and gold-plated silicon wafers are mounted in the strip-shaped concave surfaces in a matching manner.