CN117899955A - Microfluidic chip, microfluidic system and manufacturing method - Google Patents

Abstract

The invention belongs to the technical field of biochemistry and molecular biology, in particular to a microfluidic chip, a microfluidic system and a manufacturing method, comprising a chip shell and a microporous layer, wherein the microporous layer is arranged in the chip shell and is provided with a plurality of micro through holes, and the chip shell is provided with a sample injection hole; in the sample loading process, the sample can be subjected to the capillary force action of the micro through holes with high depth-to-width ratio, so that the sample is sucked into the micro through holes, and along with the forward pushing of the sample in the micro through holes, all the micro through holes can be filled with the sample finally, so that the final form of the sample is divided into a large number of micro through holes with high uniformity, the sample remained on the surface of the micro through holes can be dragged while the sample is pushed to advance in the sealing oil flowing process, the chip preparation efficiency and quality are improved, the micro through holes are simpler in processing and preparation process, the cost is lower, and complex external sample loading equipment is not needed for carrying out cooperation work.

Description

Microfluidic chip, microfluidic system and manufacturing method

Technical Field

The invention belongs to the technical field of biochemistry and molecular biology, and particularly relates to a microfluidic chip, a microfluidic system and a manufacturing method.

Background

Researchers have focused on miniaturizing and integrating experimental devices in order to increase the speed of diagnostic assays, reduce costs, and simplify operations while maintaining the accuracy of the experiments. This involves increasing the number of parallel assays on a single carrier device. Miniaturization of microfluidic devices introduces a series of challenges, such as problems with loss of liquid and consistency of micro-unit volumes. In particular, microfluidic devices suffer from sample segmentation and distribution uniformity problems when filling microfluidic structures, mainly due to the special flow behavior of the sample liquid inside the device. Microfluidic chips as a solution allow multiple assays to be performed in a miniaturized environment by providing microchannels to handle micro-liter or nano-scale sample liquids. These chips typically have microliter levels of reagent preloaded into a small unit for contact with the sample fluid flowing through the reaction flow channel. The sample amount or concentration of each cell needs to be precisely controlled. These assays are widely used in biological materials (e.g., polypeptides, nucleic acids, cells or tissues). In particular, digital PCR is an innovation that allows for more reliable and sensitive measurement of nucleic acids by dividing the sample into numerous small regions for independent reactions, marking a great advance in conventional PCR methods.

To this end, the invention provides a microfluidic chip, a microfluidic system and a method of manufacturing.

Disclosure of Invention

In order to overcome the defects in the prior art, the purpose is to provide a microfluidic chip which realizes high-uniformity segmentation and distribution of samples, and has lower cost and higher sample loading efficiency.

The invention solves the technical problems and aims to overcome the technical problems, and adopts the following technical scheme: the microfluidic chip of the present invention comprises: a chip housing; the micro-pore layer is arranged in the chip shell, a plurality of micro through holes are formed in the micro-pore layer, a micro flow channel is formed in the chip shell, and a sample injection hole is formed in the chip shell; and the sample and the sealing oil are sequentially introduced into the micro-flow channel through the sample injection hole and are pressurized, so that the sample and the sealing oil sequentially pass through the micro-through holes, the sample is sucked into the micro-through holes, and the sealing oil fully seals the micro-porous layer.

In some embodiments, the microfluidic channel is disposed in the chip housing at a location at the bottom of the micro-via, adapted for the sample and the sealing oil to pass sequentially through the bottom of the micro-via.

In some embodiments, a first sealing flow channel is arranged at the top of the microporous layer in the chip shell, and a first diversion hole is arranged in the chip shell and is communicated with the microfluidic channel and the first sealing flow channel.

In some embodiments, the chip housing is provided with an exhaust hole at the first sealing flow channel position; the dynamic viscosity of the sealing oil is larger than that of water, and the sealing oil is suitable for dragging the sample remained on the inner wall of the microfluidic channel away in the flowing process of the sealing oil.

In some embodiments, the chip housing includes a first chip upper cover and a first chip base plate, the first chip upper cover and the first chip base plate are adapted and connected so that a first mounting cavity is formed between the first chip upper cover and the first chip base plate, the first mounting cavity is provided with the microporous layer, the microfluidic channel is formed between the microporous layer and the first chip base plate, and the first sealing flow channel is formed between the microporous layer and the first chip upper cover; the first chip upper cover is close to the sample injection hole at one side of the microporous layer, the first diversion hole is arranged at the other side of the microporous layer, and the micro through hole is positioned between the sample injection hole and the first diversion hole.

In some embodiments, the first chip base plate has a first micro-fluidic channel thereon to form the micro-fluidic channel; one side of the first micro-flow groove far away from the sample injection hole is provided with a first communication area, and the first communication area and the first sealing flow channel are suitable for being mutually communicated without being blocked by the micro-porous layer.

In some embodiments, a first pad is disposed on the first chip substrate near a bottom position of the first mounting cavity, a micro-flow hole is formed on the first pad at a bottom position of the micro-through hole to form the micro-flow channel, a plurality of limiting blocks are disposed in the first mounting cavity near an edge position of the first pad, and the micro-pore layer is disposed on top of the first pad and limited by positioning of the plurality of limiting blocks.

In some embodiments, the microflow orifice comprises a drainage region, a flow expansion region and a flow forming region, wherein the flow expansion region is positioned between the drainage region and the flow forming region and is communicated with each other; the width dimension of the drainage area is smaller than that of the flow forming area, the flow expansion area is horn-shaped, the narrow end of the flow expansion area is communicated with the drainage area, the wide end of the flow expansion area is communicated with the flow forming area, and the sample and the sealing oil pass through the sample injection hole sequentially and are led into the first flow guide hole from the flow guide area, the flow expansion area and the flow forming area in sequence; the micro-holes are distributed on the micro-hole layer to form a micro-hole area, the micro-hole area is positioned at the top positions of the flow expansion area and the flow forming area, and all the micro-holes on the micro-hole area are communicated with the micro-flow channel.

In some embodiments, a mounting groove is formed in the top surface of the first chip base plate, the first base plate is arranged at the bottom of the mounting groove, a plurality of limiting blocks are arranged at the top of the first base plate and close to the side surface of the mounting groove, and the first chip upper cover is mounted at the notch of the mounting groove and limited and supported by the limiting blocks; the microporous layer with the top surface and the bottom surface of first backing plate are the plane, the tank bottom of mounting groove is the plane, first backing plate with the plane laminating between the tank bottom of mounting groove, first backing plate with contact position plane laminating between the microporous layer.

In some embodiments, a second diversion hole is arranged on the microporous layer at the bottom position of the sample injection hole, and the second diversion hole is communicated with the sample injection hole and the micro-flow channel; and an observation spacer is arranged on the first chip upper cover at the top of the micro-through hole, and the observation spacer is a light-transmitting material product.

In some embodiments, the micro-vias are high aspect ratio vias; the surface of the microporous layer is provided with a first hydrophobic area, the inner wall of the micro-through hole is provided with a hydrophilic area, the first chip bottom plate is provided with a second hydrophobic area at the position of the micro-flow channel, and the first chip upper cover is provided with a third hydrophobic area at the position of the sample injection hole.

In some embodiments, the microfluidic channel is disposed in the chip housing at a top position of the micro-through hole, adapted for the sample and the sealing oil to pass sequentially over the top of the micro-through hole; the chip shell can further comprise a second chip upper cover and a second chip bottom plate, wherein the second chip upper cover is matched with and connected with the second chip bottom plate, so that a second mounting cavity is formed between the second chip upper cover and the second chip bottom plate, the micro-pore layer is arranged in the second mounting cavity, the micro-flow channel is formed between the micro-pore layer and the second chip upper cover, and a second sealing flow channel is formed between the micro-pore layer and the second chip bottom plate; the sample is introduced into the micro-flow channel through the sample injection hole and is separated and loaded at the top position of the micro-porous layer, and the sealing oil flows into the second sealing flow channel from the micro-flow channel and is fully sealed to the micro-porous layer.

In some embodiments, a second pad is arranged on the second chip upper cover at a position close to the top of the second mounting cavity, and a micro-flow hole is formed in the second pad at the top of the micro-through hole so as to form the micro-flow channel; or, the second chip upper cover is provided with the second backing plate at the top and bottom positions close to the second mounting cavity, and the second backing plate is provided with a micro-flow hole at the micro-through hole position to form the micro-flow channel or the second sealing flow channel.

In some embodiments, when the second chip upper cover is provided with a second pad at a position only near the top of the second mounting cavity, the second chip bottom plate is provided with a second micro-groove matched with the micro-flow hole so as to form the second sealing flow channel; the second micro flow groove and one side of the micro flow hole far away from the sample injection hole are respectively provided with a second communication area, and the second communication areas are suitable for being mutually communicated without being blocked by the micro-porous layer.

A microfluidic system employing the microfluidic chip described above, comprising: a plurality of the microfluidic chips; and a plurality of microfluidic chips are connected.

A manufacturing method of a micro-fluidic chip is used for preparing the micro-fluidic chip and comprises the following method steps:

Firstly, adding the sample into the sample injection hole, and then adding the sealing oil into the sample injection hole;

applying positive pressure to the sample injection hole, wherein the sealing oil under the positive pressure pushes the sample into the micro-flow channel;

the sample flows through the microporous layer along the microfluidic channel, and is divided and sucked into the micro-through holes under the capillary force of the micro-through holes on the microporous layer;

The sealing oil continuously pushes the sample to flow along the micro-flow channel, the sample is further sucked by the micro-through holes at the front part of the flow direction, and the sealing oil cleans the residual sample on the inner wall of the micro-flow channel;

and the sealing oil continuously advances forward and enters the top of the microporous layer, fills the inside of the chip shell and fully seals the microporous layer so as to finish the preparation of the microfluidic chip.

Compared with the prior art, the microfluidic chip, the microfluidic system and the manufacturing method provided by the invention have the following beneficial effects:

1. The invention provides a microfluidic chip, a microfluidic system and a manufacturing method, wherein a chip shell and a microporous layer are arranged, a plurality of micro through holes are formed in the microporous layer, a micro flow channel for sample and sealing oil to flow and sample is formed in the bottom of the microporous layer, the sample can be sucked into the micro through holes under the action of capillary force of the micro through holes with high aspect ratio, and all the micro through holes can be filled with the sample along with the forward pushing of the sample in the micro flow channel, so that the final form of the sample is divided and distributed in a large number of micro through holes with high uniformity, the sealing oil effectively pushes the sample to advance and drag the sample remained on the bottom surface of the microporous layer, the chip preparation efficiency and quality are improved, the micro flow channel processing and the preparation process are simpler, the cost is lower, and complex external sample loading equipment is not needed for carrying out cooperation work.

2. The invention provides a microfluidic chip, a microfluidic system and a manufacturing method, wherein a drainage area, a flow expansion area and a flow forming area are adopted, when a sample and sealing oil are led into a microfluidic channel formed by a microfluidic hole, the sample firstly enters the drainage area and then enters the flow expansion area and then enters the flow forming area, the sample is kept to be pushed forward at approximately the same speed through the effective guidance of the flow expansion area, the problem of trapped air in the sample loading process is reduced, the uniform separation of the sample is facilitated, and the phenomenon that more samples cannot be effectively utilized due to the fact that part of the flow velocity of the sample flows out of the microfluidic channel in advance is avoided.

3. The invention provides a microfluidic chip, a microfluidic system and a manufacturing method, which adopt high-viscosity sealing oil, and can better drag water molecules attached to the bottom surface of a microporous layer in the process of pushing a sample to flow, so that residual samples on the inner wall of a microfluidic channel can be effectively dragged away, thereby removing the residual samples on the inner wall of the microfluidic channel, particularly the bottom surface of the microporous layer, reducing the influence on the later detection precision, avoiding influencing the subsequent PCR reaction, and naturally dragging the residual samples attached to the top surface of the microporous layer in the process of pushing the sealing oil.

Drawings

The invention is further described below with reference to the accompanying drawings:

FIG. 1 is an exploded view of a microfluidic chip in a bottom loading embodiment of the present invention;

FIG. 2 is an exploded view of a microfluidic chip in another bottom loading embodiment of the present invention;

FIG. 3 is an exploded view of a microfluidic chip in another bottom loading embodiment of the present invention;

FIG. 4 is an exploded view of a microfluidic chip in a top loading embodiment of the present invention;

FIG. 5 is an exploded view of a microfluidic chip in another top loading embodiment of the present invention;

fig. 6 is a perspective view of a microfluidic system in one embodiment of the present invention;

fig. 7 is a flowchart of a method of manufacturing a microfluidic chip in an embodiment of the present invention.

In the figure: chip housing 100, first chip upper cover 110, sample injection hole 111, exhaust hole 112, observation spacer 113, first chip bottom plate 120, mounting groove 121, first micro-groove 122, first communication area 123, second chip upper cover 130, second chip bottom plate 140, second micro-groove 141, second communication area 142, and second chip upper cover,

Microporous layer 200, microperforations 210, first deflector aperture 220, microporous region 230, second deflector aperture 240, hydrophilic region 250,

A microfluidic channel 300,

A first sealing flow passage 400, a second sealing flow passage 410,

A first pad 500, a drainage region 510, a flow expansion region 520, a flow formation region 530, a second pad 540, micro-holes 550,

A limiting block 600,

A first hydrophobic region 700,

Second hydrophobic region 800,

And a third hydrophobic region 900.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will explain the specific embodiments of the present invention with reference to the accompanying drawings. It is evident that the drawings in the following description are only examples of the invention, from which other drawings and other embodiments can be obtained by a person skilled in the art without inventive effort.

For simplicity of the drawing, only the parts relevant to the invention are schematically shown in each drawing, and they do not represent the actual structure thereof as a product. Additionally, in order to simplify the drawing for ease of understanding, components having the same structure or function in some of the drawings are shown schematically with only one of them, or only one of them is labeled. Herein, "a" means not only "only this one" but also "more than one" case.

It should be further understood that the term "and/or" as used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

In this context, it should be noted that the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, unless explicitly stated or limited otherwise; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

In addition, in the description of the present invention, the terms "first," "second," and the like are used merely to distinguish between descriptions and are not to be construed as indicating or implying relative importance.

As shown in fig. 1 to 5, this embodiment provides a microfluidic chip, including a chip housing 100 and a microporous layer 200, in which a sample injection hole 111 is formed in the chip housing 100, when the microfluidic chip is produced, a sample is injected into the sample injection hole 111, and then sealing oil is injected into the sample injection hole, and the sealing oil is pushed by pressure through a pressurizing manner at the mouth of the sample injection hole 111, and then the sealing oil pushes the sample to flow, so that the sample and the sealing oil sequentially enter a microfluidic channel 300, and then the sample is separated and respectively enter microcavities on the surface of the microporous layer 200, and then the microporous layer 200 is sealed by the sealing oil.

Digital PCR (dPCR) is a molecular technique used to precisely quantify DNA or RNA. This technique achieves high accuracy quantification by dividing the sample into thousands of separate small reactions, each of which contains only zero or a few DNA molecules, and then calculating by poisson distribution.

The digital PCR micro-fluidic chip is a dPCR technical platform. Such chips utilize microfluidic technology to segment DNA samples into a large number of tiny oil droplets or micro-reaction chambers. Each oil droplet or reaction chamber, like a separate PCR reaction environment, may contain few or no target DNA molecules. By counting the amplified signals in these oil droplets or micro-reaction chambers, the number of target DNA molecules in the original sample can be estimated very accurately. The method has the advantages of extremely high precision and sensitivity, and is very useful in the fields of detection of low-abundance samples, single-cell analysis, gene expression level analysis, mutation detection, pathogen detection and the like.

However, this technique also faces a series of challenges such as loss of sample liquid, uniformity of the volume of the micro-reaction chamber, uniformity of sample division and distribution, difficulty and cost of manufacturing the micro-fluidic channel and the micro-reaction chamber, complexity of the sample division and distribution process, and the like.

In this embodiment, through the arrangement of the microporous layer 200 in the chip housing 100, the surface of the microporous layer 200 is provided with the plurality of micro through holes 210, the micro through holes 210 penetrate through the whole microporous layer 200 up and down, the bottom position of the microporous layer 200 is provided with the micro flow channels 300, the micro flow channels 300 are flow channels formed by enclosing between the inner wall of the chip housing 100 and the microporous layer 200 and used for flowing sample and sealing oil, the whole microporous layer 200 separates the inside of the chip housing 100 to form an upper cavity and a lower cavity, the bottom cavity of the microporous layer 200 forms the micro flow channels 300, the top cavity of the microporous layer 200 can also be filled with sealing oil to realize covering and sealing on the top of the microporous layer 200, the upper cavity and the lower cavity of the microporous layer 200 can be communicated, and the communicating positions are arranged at positions far away from the sample injection holes 111; of course, in another embodiment, the micro-fluidic channel 300 is not excluded from being disposed at the top of the micro-porous layer 200, and during the loading process, the sample and the sealing oil are directly introduced into the micro-fluidic channel 300 at the top of the micro-porous layer 200 through the sample injection holes 111 in sequence under pressure, so that when the sample flows in the micro-fluidic channel 300, the sample is loaded at the top of the micro-porous layer 200, and is introduced into the micro-through holes 210 in a uniformly divided manner; in other embodiments, the microfluidic channel 300 may be disposed at the bottom of the microporous layer 200, and during loading, the microfluidic chip may be turned over integrally, so that the microfluidic channel 200 may be turned over to the top of the microfluidic channel 300, thereby meeting the requirement of loading samples at the top.

Further, the communicating positions of the sample injection hole 111 and the upper and lower chambers of the microporous layer 200 are respectively located near two ends of the microporous layer 200, and when the microfluidic chip is manufactured, a sample and a sealing oil are sequentially injected through the sample injection hole 111, wherein the sample is a biological material, preferably polypeptide, nucleic acid, cell or tissue, the sealing oil is preferably high-viscosity silicone oil, and may also be mineral oil, fluorinated oil or the like, and the viscosity of the sealing oil is higher than that of the sample, such as: at 25 ℃, the dynamic viscosity of the sealing oil is greater than that of water (0.89 cp), and at the moment, the sealing oil can have better dragging effect on the residual sample, and the like, so that the quality of the microfluidic chip after sample loading is improved; applying forward pressure at the opening position of the sample injection port, so that the sample and the sealing oil sequentially enter the micro-flow channel 300, the sealing oil is pushed by the forward pressure, the sealing oil further pushes the sample, so that the sample flows from one end position to the other end position of the bottom of the micro-pore layer 200, and therefore, the sample also passes through the micro-pore 210, because the micro-pore 210 is designed with high depth-to-width ratio, and the micro-pore 210 is intensively distributed on the micro-pore layer 200, the micro-pore 210 is distributed at the top of the micro-flow channel 300 and is matched with the shape of the micro-pore layer 300 in the whole horizontal direction, the sample is subjected to the capillary force action of the micro-pore 210 with high depth-to-width ratio, so that the sample is sucked into the micro-pore 210, and as the sample advances forward in the micro-flow channel 300, and finally, the sample fills all the micro-pore 210, so that the final form of the sample is divided and distributed in a large number of micro-pore 210, and under the positive pressure, the sealing oil continues to advance, fills up the micro-flow channel 300, and the sealing oil also continues to flow upward from the upper and lower communication position of the micro-pore layer 200, namely from the bottom position of the micro-pore layer 200 to the top of the micro-pore layer 200, and the final cavity 200 can be further understood as the final cavity, where the top of the micro-pore layer is filled up: the core purpose of the method is to seal the microporous layer 200 on the upper and lower sides of a large number of micro-holes 210, so that for convenience in operation, requirement for later observation, sample quality and the like, it is preferable to use to fully fill the internal cavity of the chip housing 100 to realize the whole wrapping and full sealing of the microporous layer 200, wherein the full sealing does not necessarily wrap all surfaces of the microporous layer 200, because the contact surface of the microporous layer 200 is partially limited to be not in an open state, the core of the full sealing is to seal the microporous layer 200 after the samples have been uniformly separated and distributed through sealing oil, so as to avoid continuous contact between the samples and the external environment, and ensure the sample quality and the like.

Further, the manner of applying positive pressure to the wells 111 is not particularly limited as long as forward pressure is satisfied to push the sealing oil and the sample to flow to prepare the microfluidic chip, for example, a syringe may be used, a manner of manually injecting the sealing oil toward the wells 111 and applying forward pressure to push the sealing oil, etc., and the forward pressure means applying positive pressure toward the inside of the wells 111 is not limited thereto.

Further, in this embodiment, during the process of pushing the sample to flow in the microfluidic channel 300 by the sealing oil, part of the liquid sample may remain on the bottom surface of the microporous layer 200, and since the density of the sealing oil is lower than that of the sample and the viscosity of the sealing oil is higher than that of the sample in this embodiment, the sealing oil can be effectively kept in contact with the bottom surface of the microporous layer 200 at a certain pressure and flow in a preset flow direction, and the sealing oil can remove the sample remaining on the bottom surface of the microporous layer 200 due to its relatively high viscosity, which is specifically described as the following principle: the high-viscosity sealing oil has slower fluidity and higher viscosity than the liquid sample fluidity, so that the sealing oil can more effectively drag the residual sample adhered to the bottom surface of the microporous layer 200, the sample on the bottom surface of the microporous layer 200 is removed, the sample under observation can be basically and uniformly concentrated in each micro through hole 210, the detection precision is effectively improved, the influence on the subsequent PCR reaction is avoided, and the residual sample adhered to the top surface of the microporous layer 200 can be dragged in the same sealing oil flowing process.

Further, in order to ensure that the sample and the sealing oil fill the internal cavity of the chip housing 100, the internal air pressure of the chip housing 100 is balanced, and a conventional vent 112 may be disposed on the chip housing 100, it is preferable to dispose the vent 112 at the top of the chip housing 100, so that after the sealing oil fills the whole chip housing 100, if excessive sealing oil can enter the vent 112, the risk of air trapping inside the chip housing 100 is reduced, and the chip quality is ensured, and in other embodiments, when the sealing oil is injected into the sample injection hole 111 and positive pressure is applied, a small gap is properly left to serve as a vent, and the method is not limited thereto; in another embodiment, sealing oil may also be injected into the interior of the chip housing from the vent 112 while leaving sufficient clearance for venting.

Further, the number and distribution of the sample injection holes 111 may be adaptively adjusted according to the need, for example, a plurality of sample injection holes 111 may be adopted, or the same sample injection hole 111 may be divided into a plurality of channels in the inner portion of the chip housing 100, so that the sample and the sealing oil may flow into different positions of the microfluidic channel 300 respectively, and the sample flow separation and distribution are realized through the plurality of positions, and finally the sealing oil in a plurality of directions is collected and seals the microporous layer 200, so as to improve the chip preparation efficiency, and the like, but is not limited thereto.

In one embodiment, by disposing the first sealing flow channel 400 at the top position of the microporous layer 200 in the chip housing 100, on one hand, the first sealing flow channel 400 can provide a pressure regulating effect for the micro through holes 210, when the sample is sucked into the micro through holes 210, the gas inside the micro through holes 210 can be discharged into the first sealing flow channel 400, so as to ensure that the sample is smoothly and uniformly separated and introduced into a plurality of micro through holes 210, and on the other hand, when the sealing oil enters the top position of the microporous layer 200, the sealing oil flows in the first sealing flow channel 400, so as to realize the covering and sealing of the top surface of the microporous layer 200;

Further, the first diversion hole 220 may be disposed in the chip housing 100, the first diversion hole 220 communicates with the microfluidic channel 300 and the first sealing flow channel 400, after the sealing oil is introduced into the microfluidic channel 300 from the sample injection hole 111, the sealing oil flows in the microfluidic channel 300, and after passing through the micro through holes 210 on the microporous layer 200, the sealing oil enters into the first diversion hole 220, and is introduced into the first sealing flow channel 400 through the first diversion hole 220, and then the sealing oil seals the top surface of the microporous layer 200 through the first sealing flow channel 400.

In one implementation, the chip housing 100 is provided with the air vent 112, the air vent 112 is arranged at a position corresponding to the first sealing flow channel 400, so that the chip housing 100 has the capability of exhausting air upwards, after sealing oil is introduced into the micro-flow channel 300, the air in the micro-flow channel 300 enters the first sealing flow channel 400 through the first air guide hole 220 along with the pushing of the sample flowing, and as the air vent 112 is arranged at the position of the first sealing flow channel 400, the air vent 112 communicates the first sealing flow channel 400 with the outside, so that the air in the first sealing flow channel 400 is led out, and the adjustment of the internal and external air pressure of the chip housing 100 is realized;

In one embodiment, the sealing oil is a high-viscosity silicone oil, which has better viscosity performance than mineral oil, and can better drag water molecules attached to the bottom surface of the microporous layer 200 in the process of pushing the sample to flow, so that the residual sample on the inner wall of the microfluidic channel 300 can be effectively dragged away, thereby removing the residual sample on the inner wall of the microfluidic channel 300, particularly on the bottom surface of the microporous layer 200, and reducing the influence on the later detection.

In one embodiment, the chip housing 100 includes a first chip upper cover 110 and a first chip bottom plate 120, so that the micro-porous layer 200 is assembled in the first chip upper cover 110 and the first chip bottom plate 120, the first chip upper cover 110 and the first chip bottom plate 120 are connected in a sealing manner to form the chip housing 100, and a first mounting cavity is formed between the first chip upper cover 110 and the first chip bottom plate 120, and the first mounting cavity can be separated into a micro-fluid channel 300 and a first sealing flow channel 400 by the micro-porous layer 200, wherein the micro-fluid channel 300 is located at the bottom position of the micro-porous layer 200, and the first sealing flow channel 400 is located at the top position of the micro-porous layer 200;

Further, the sample injection hole 111 is located near one end of the microporous layer 200, and the first diversion hole 220 is located near the other end of the microporous layer 200, so that a large number of micro through holes 210 on the microporous layer 200 can be located between the sample injection hole 111 and the first diversion hole 220, after the sample and the sealing oil are introduced into the micro flow channel 300 from the sample injection hole 111, the sample and the sealing oil can effectively pass through the micro through holes 210, so that the sample is uniformly separated and effectively introduced into the micro through holes 210, and then the sealing oil enters the first diversion hole 220, so that the sealing oil can seal the microporous layer 200 up and down.

In an embodiment, the first micro-groove 122 may be further directly disposed on the first chip bottom plate 120, and the micro-flow channel 300 is formed by matching the first micro-groove 122 with the micro-porous layer 200, and further, by disposing the first communication area 123 at a position of the first micro-groove 122 away from the sample injection hole 111, the width of the first communication area 123 is larger than that of other areas of the first micro-groove 122, and the first communication area 123 is not blocked by the micro-porous layer 200, so that the micro-flow channel 300 and the first sealing flow channel 400 can be effectively communicated.

In one embodiment, by disposing the first pad 500 on the first chip base plate 120 at the bottom position of the first mounting cavity and disposing the micro-hole 550 on the first pad 500, disposing the micro-hole 200 on the top position of the first pad 500 such that the micro-hole 550 forms the micro-channel 300, and disposing the stopper 600 on the first pad 500, restricting the micro-hole 200 by the stopper 600, and when the first chip base plate 120 and the first chip upper cover 110 are mounted, a gap is preset between the first chip upper cover 110 and the micro-hole 200, so as to form the first sealing flow channel 400, the manner of the preset gap is not limited, for example, the first chip upper cover 110 is mounted on the spacer, and the height dimension of the spacer is greater than the thickness dimension of the micro-hole 200, so that when the first chip upper cover 110 is placed on the spacer, the bottom surface of the first chip upper cover 110 will have a gap with the micro-hole layer 200;

in other embodiments, a step surface may be provided on the opposite side of the first chip upper cover 110 or the first chip bottom plate 120, so that a gap or the like is formed between the bottom surface of the first chip upper cover 110 and the top surface of the microporous layer 200 after the sealing and mounting are positioned, which is not limited thereto.

In one embodiment, the micro-hole 550 includes a drainage area 510, a flow expansion area 520, and a flow forming area 530, where the drainage area 510, the flow expansion area 520, and the flow forming area 530 are sequentially and mutually communicated to form an integral micro-hole 550, and the micro-hole 550 penetrates up and down through the first pad 500, so that a sample and sealing oil entering the micro-hole 550 can flow on an inner top surface of the first chip bottom plate 120, so as to facilitate rapid assembly and form a preset micro-flow channel 300 shape, to adapt to a distribution shape of the micro-hole 210, for example, the integral distribution of the micro-hole 210 can be a rectangular array structure or a hexagonal close-packed structure, etc., and of course, the shape of the micro-hole can also be selected according to practical situations, for example, a circular shape or a polygonal shape, etc., without being limited thereto, and the sample or the sealing oil will not have steps in the flowing process inside the micro-flow channel 300, so that the sealing oil is always located on the top surface of the first chip bottom plate 120 and the top surface is a plane in the micro-flow channel 300;

Further, the width dimension of the drainage region 510 is smaller than that of the flow forming region 530, the width direction refers to the direction along the horizontal plane and perpendicular to the overall flow direction of the sealing oil, the flow expansion region 520 can effectively optically and smoothly connect the drainage region 510 and the flow forming region 530, if a horn-shaped section or a splayed shape can be adopted, the micro-holes 210 are distributed to form the micro-hole region 230, the micro-hole region 230 is positioned at the top positions of the flow expansion region 520 and the flow forming region 530, when the sample and the sealing oil are introduced into the micro-flow channel 300 formed by the micro-hole 550, the sample firstly enters the drainage region 510, then enters the flow expansion region 520 and then enters the flow forming region 530, enters the first flow expansion hole 220 through the flow forming region 530, so as to realize the flow towards the top direction of the micro-hole layer 200, the sample passing through the flow expansion region 520 and the flow forming region 530 can be sucked into a large number of micro-holes 210 in the micro-hole region 230, so as to realize the uniform separation of the sample, by the flow expansion region 520, it is realized that the sample and the seal oil are relatively advanced at a constant speed, that is, when the sample or the seal oil flows in a preset direction, a flowing separation line is formed by the flowing direction of the sample or the seal oil depending on the corresponding front end position, if a separation line is formed between the sample and the no sample, the separation line is formed between the sample and the seal oil, and by the effective guiding of the flow expansion region 520, the separation line can be advanced at the same speed while maintaining a relatively straight state, so that the internal gas of the micro-fluidic channel 300 can be effectively introduced into the first diversion hole 220 and finally discharged, and compared with the case that the diversion region 510 has a larger width, the sample or the seal oil introduced into the diversion region 510 through the sample injection hole 111 will be firstly present as an emission-shaped flow in the circumferential direction, the problem of local gas will easily occur, or the uniform separation of the sample will also have a certain influence, in this embodiment, the flow expansion region 520 makes the sample and the sealing oil present a fan-shaped flow, so that the forward flow of the sample and the sealing oil is more uniform.

In other embodiments, the microporous region 230 may also be separately located at the top of the streaming region 530, but is not limited thereto.

In one embodiment, the top surface of the first chip bottom plate 120 is provided with a mounting groove 121, the bottom of the mounting groove 121 is provided with a first base plate 500, the top of the first base plate 500 is provided with a limiting block 600 near the peripheral position thereof, the first chip upper cover 110 is arranged at the top of the limiting block 600 and is supported by the limiting block 600, and the first chip upper cover 110 is matched with the notch of the mounting groove 121, so that the mounted first chip upper cover 110 seals the notch of the mounting groove 121;

Further, by setting the top surface and the bottom surface of the microporous layer 200, the first pad 500 and the bottom surface of the mounting groove 121 to be flat, the mounting groove 121, the first pad 500 and the microporous layer 200 have better connection effect, have better tightness at the connection contact surface, reduce the problem of penetration between the sample and the tightness towards the connection contact surface, and certainly reduce the problem of deformation or internal stress generated in the mounting process, and improve the precision and stability of the assembled microfluidic chip.

In one embodiment, the second diversion hole 240 is arranged at the bottom of the sample injection hole 111 on the microporous layer 200, and the second diversion hole 240 is communicated with the sample injection hole 111 and the microfluidic channel 300, so that the microporous layer 200 can have a larger area except for the area of the micro through holes 210, the connection stability and the limiting effect after installation are improved, on the basis, the sample injection hole 111 can be designed at a position close to the micro through holes 210 through the design of the second diversion hole 240, and the sample injection efficiency can be higher in the sample separation and sealing process of sealing oil.

In one embodiment, the first chip upper cover 110 is provided with the observation spacer 113, and the observation spacer 113 is made of a light-transmitting material, so that the situation of the micro-through hole 210 area is conveniently observed before, during and after sample loading, and the sample loading operation and sample loading quality confirmation are conveniently carried out;

Further, the viewing spacer 113 may be closer to the microporous layer 200 than the bottom surface of the first chip upper cover 110 to more facilitate clear viewing of the loading.

In one embodiment, the micro-vias 210 are high aspect ratio vias, so that the micro-vias 210 have better capillary force, so that when the sample flows through the bottom of the micro-vias 210, the sample can be more effectively sucked into the micro-vias 210, so as to achieve uniform division and distribution of the sample, and the area of the micro-vias 210 in the micro-porous layer 200 contains tens of thousands of micro-vias 210 with high aspect ratio, such as: the micro through holes 210 have a diameter of 50 micrometers, a height of 500 micrometers, etc., and can be realized with a better Mao Xili, and can effectively meet the uniform division and distribution of the sample, but are not limited thereto.

Further, the first chip bottom plate 120 has a flow channel height of 100 micrometers, the surface of the microporous layer 200 is provided with the first hydrophobic region 700, the inner wall of the micro-through hole 210 is provided with the hydrophilic region 250, the first chip bottom plate 120 is provided with the second hydrophobic region 800 at the position of the micro-flow channel 300, the first chip upper cover 110 is provided with the third hydrophobic region 900 at the position of the sample injection hole 111, and the like, and water delivery treatment can be performed at other positions or other positions which are in contact with the sample and the sealing oil, so that the micro-through hole 210 with the hydrophilic region 250 can better absorb the liquid sample with a large amount of water, the risk that the sealing oil enters the micro-through hole 210 is reduced, the effect of better absorbing the sample and locking the sample can be achieved, and the sample or other regions through which the sealing oil passes are provided with the hydrophobic layer on the contact wall, so that the sample remains in other non-preset regions, such as the surface of the microporous layer 200, the inner wall of the sample injection hole 111, and the like can be further reduced.

Further, the material of the microporous layer 200 may be one or more of silicon, silicon oxide, glass, plastic, etc., but is not limited thereto, the material of the first chip base 120 may be one or more of silicon, silicon oxide, glass, plastic, metal, etc., but is not limited thereto, and the material of the first chip upper cover 110 may be one or more of PP, COC, COP, etc., and other optically transparent injection-moldable materials.

In one embodiment, when the microfluidic channel 300 in the chip housing 100 is located at the top position of the microporous layer 200, the sample is uniformly divided from the top position of the micro-through hole 210 to be loaded when the sample passes through the microfluidic channel 300;

Specific implementations may recommend two, but are not limited thereto;

First: the top of the micro-through hole 210 can be loaded by turning over the microfluidic chip, which has been described in detail and will not be described here;

Second,: by directly disposing the microfluidic channel 300 at the top position of the microporous layer 200, in particular: the gap between the microporous layer 200 and the inner top surface of the chip housing 100 may be reserved directly to form the microfluidic channel 300, and in order to ensure the position stability of the microporous layer 200, the method may be implemented by one or more combination modes of clamping, plugging, welding, clamping, bonding, etc., which is not particularly limited herein;

further, the chip housing 100 may further include a second chip upper cover 130 and a second chip bottom plate 140, a second mounting cavity is provided between the second chip upper cover 130 and the second chip bottom plate 140, a micro-porous layer 200 is disposed in the second mounting cavity, a micro-flow channel 300 is disposed between the micro-porous layer 200 and the second chip upper cover 130, a sample injection hole 111 is communicated with the micro-flow channel 300, and sample and sealing oil are sequentially injected into the micro-flow channel 300 through the sample injection hole 111, so that top sample loading from the micro-porous layer 200 is realized;

Further, by disposing the second pad 540 at the top position of the microporous layer 200, or disposing the second pad 540 at both the top and bottom positions of the microporous layer 200, and having the micro-holes 550 on the second pad 540, for example, the second pad 540 at the top position is surrounded by the second chip upper cover 130 and the microporous layer 200, so that the micro-holes 550 at the top position form the micro-fluidic channels 300, and similarly, the second pad 540 at the bottom position may be surrounded by the second chip bottom plate 140 and the microporous layer 200, so that the micro-holes 550 at the bottom position form the second sealed channels 410, the second sealed channels 410 are communicated with the micro-fluidic channels 300, and the communicating position is located away from the sample injection holes 111, so that the sample injection holes 111 may preferably be one side position of the microporous layer 200, and the communicating position of the micro-fluidic channels 300 and the second sealed channels 410 may preferably be the other side position of the microporous layer 200, which needs to be emphasized that: the micro through holes 210 may also communicate the micro flow channels 300 and the second sealing flow channels 410, and the communication positions refer to other communication positions besides the micro through holes 210; when the sample and the sealing oil are introduced through the sample injection hole 111, the sample can be fully and uniformly separated and sucked into the micro through holes 210, so that all the micro through holes 210 can be effectively sampled, and then the sealing oil can enter the second sealing flow channel 410 through the communication position, so that the filling of the micro flow channel 300 and the second sealing flow channel 410 by the sealing oil is realized, and the full sealing of the microporous layer is further realized.

When the second pad 540 is disposed only at the top of the microporous layer 200, a gap is also formed between the bottom of the microporous layer 200 and the second chip bottom plate 140, so that the bottom of the microporous layer 200 may directly form the second sealing flow channel 410, for example, one or more combinations of fastening, plugging, welding, clamping, and bonding are used to limit the position of the microporous layer, which is not specifically limited herein;

In one embodiment, the second micro-groove 141 is disposed on the second chip bottom plate 140, the second sealing flow channel 410 is formed between the second micro-groove 141 and the micro-hole layer 200, further, the second communicating region 142 is disposed between the micro-groove and the micro-hole 550 at a position far away from the sample injection hole 111, the width of the second communicating region 142 is larger than other regions on the second sealing flow channel 410, and the upper and lower second communicating regions 142 are not blocked by the micro-hole layer 200, so that the two second communicating regions 142 can maintain a mutual communicating state, and in other embodiments, the micro-hole layer 200 can also partially shield the second communicating region 142, not limited thereto.

As shown in fig. 6, a microfluidic system is formed by combining and splicing a plurality of microfluidic chips, for example, the microfluidic system can be formed by arranging a plurality of microfluidic chips side by side and combining and extending the microfluidic chips in a linear direction, which is not limited by the manner of arranging the microfluidic chips like a chessboard or other alternative manners, and in other embodiments, in order to ensure that the relative positions of the microfluidic chips are stable, quick assembly can be realized, or by arranging a mounting plate, a mounting area, such as a mounting groove, on the mounting plate according to the requirements, the microfluidic chips can be directly mounted in the mounting area, so that a stable integral system can be formed by quickly assembling the microfluidic chips, further, in order to ensure that the microfluidic chips can be uniformly and quickly loaded, uniform channels can be further arranged on the mounting plate, and the like, and the method is not particularly limited.

As shown in fig. 7, a method for manufacturing a microfluidic chip, for manufacturing the microfluidic chip, includes the following method steps:

s100: firstly, adding the sample into the sample injection hole 111, and then adding the sealing oil into the sample injection hole 111;

S200: applying positive pressure to the sample injection well 111, wherein the sealing oil under positive pressure pushes the sample into the microfluidic channel 300;

S300: the sample flows under the microporous layer 200 along the microfluidic channel 300 and is divided and sucked into the micro-holes 210 by capillary force of the micro-holes 210 on the microporous layer 200;

S400: the sealing oil continuously pushes the sample to flow along the microfluidic channel 300, the sample is further sucked by the micro through holes 210 at the front of the flow direction, and the sealing oil cleans the sample remaining on the inner wall of the microfluidic channel 300;

s500: the sealing oil continues to advance and enter the top of the microporous layer 200, fills the inside of the chip housing 100 and seals the microporous layer 200 completely, so as to complete the preparation of the microfluidic chip.

The manufacturing method can realize the high-uniformity segmentation and distribution of the samples, does not need to process the complex microfluidic channel 300, has simple process, does not need complex external sample loading equipment to carry out cooperation work, and has shorter sample loading time; the high aspect ratio micro-via 210 structure utilizes capillary forces to achieve more uniform sample segmentation and distribution; the sample utilization rate is high, and almost no waste is generated; the sample loading speed is higher, and the sample loading can be completed within 10 seconds generally; the chip has simple structure, small processing difficulty and low cost; the sample loading equipment is simple, the implementation difficulty is small, and the cost is low.

The foregoing has shown and described the basic principles, principal features and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (16)

1. A microfluidic chip, comprising:

A chip housing;

the micro-pore layer is arranged in the chip shell, a plurality of micro through holes are formed in the micro-pore layer, a micro flow channel is formed in the chip shell, and a sample injection hole is formed in the chip shell;

And the sample and the sealing oil are sequentially introduced into the micro-flow channel through the sample injection hole and are pressurized, so that the sample and the sealing oil sequentially pass through the micro-through holes, the sample is sucked into the micro-through holes, and the sealing oil fully seals the micro-porous layer.

2.A microfluidic chip according to claim 1, wherein,

The microfluidic channel is arranged at the bottom of the micro-through hole in the chip shell, and is suitable for the sample and the sealing oil to sequentially pass through the bottom of the micro-through hole.

3. A microfluidic chip according to claim 2, wherein,

The chip comprises a chip shell, and is characterized in that a first sealing flow channel is arranged at the top of the microporous layer in the chip shell, a first diversion hole is arranged in the chip shell, and the first diversion hole is communicated with the microfluidic channel and the first sealing flow channel.

4. A microfluidic chip according to claim 3, wherein,

The chip shell is provided with an exhaust hole at the position of the first sealing flow channel;

The dynamic viscosity of the sealing oil is larger than that of water, and the sealing oil is suitable for dragging the sample remained on the inner wall of the microfluidic channel away in the flowing process of the sealing oil.

5. A microfluidic chip according to claim 4, wherein,

The chip shell comprises a first chip upper cover and a first chip bottom plate, wherein the first chip upper cover is matched with and connected with the first chip bottom plate, so that a first mounting cavity is formed between the first chip upper cover and the first chip bottom plate, the first mounting cavity is internally provided with the micropore layer, the micro-flow channel is formed between the micropore layer and the first chip bottom plate, and the first sealing flow channel is formed between the micropore layer and the first chip upper cover;

The first chip upper cover is close to the sample injection hole at one side of the microporous layer, the first diversion hole is arranged at the other side of the microporous layer, and the micro through hole is positioned between the sample injection hole and the first diversion hole.

6. A microfluidic chip according to claim 5, wherein,

The first chip bottom plate is provided with a first micro-groove so as to form the micro-flow channel;

One side of the first micro-flow groove far away from the sample injection hole is provided with a first communication area, and the first communication area and the first sealing flow channel are suitable for being mutually communicated without being blocked by the micro-porous layer.

7. A microfluidic chip according to claim 5, wherein,

The micro-flow channel is characterized in that a first base plate is arranged at the bottom position, close to the first mounting cavity, of the first chip base plate, micro-flow holes are formed in the bottom position of the micro-through holes in the first base plate to form the micro-flow channel, a plurality of limiting blocks are arranged at the edge position, close to the first base plate, of the inner portion of the first mounting cavity, and the micro-pore layer is arranged at the top of the first base plate and is limited by the positioning of the limiting blocks.

8. The microfluidic chip according to claim 7, wherein,

The micro-flow hole comprises a drainage area, a flow expansion area and a flow forming area, wherein the flow expansion area is positioned between the drainage area and the flow forming area and is communicated with each other;

The width dimension of the drainage area is smaller than that of the flow forming area, the flow expansion area is horn-shaped, the narrow end of the flow expansion area is communicated with the drainage area, the wide end of the flow expansion area is communicated with the flow forming area, and the sample and the sealing oil pass through the sample injection hole sequentially and are led into the first flow guide hole from the flow guide area, the flow expansion area and the flow forming area in sequence;

The micro-holes are distributed on the micro-hole layer to form a micro-hole area, the micro-hole area is positioned at the top positions of the flow expansion area and the flow forming area, and all the micro-holes on the micro-hole area are communicated with the micro-flow channel.

9. The microfluidic chip according to claim 7, wherein,

The top surface of the first chip bottom plate is provided with a mounting groove, the bottom of the mounting groove is provided with a first base plate, the top of the first base plate is provided with a plurality of limiting blocks close to the side surface of the mounting groove, and the first chip upper cover is mounted at the notch of the mounting groove and is limited and supported by the limiting blocks;

the microporous layer with the top surface and the bottom surface of first backing plate are the plane, the tank bottom of mounting groove is the plane, first backing plate with the plane laminating between the tank bottom of mounting groove, first backing plate with contact position plane laminating between the microporous layer.

10. The microfluidic chip according to claim 7, wherein,

A second diversion hole is arranged at the bottom of the sample injection hole on the microporous layer, and the second diversion hole is communicated with the sample injection hole and the microfluidic channel;

And an observation spacer is arranged on the first chip upper cover at the top of the micro-through hole, and the observation spacer is a light-transmitting material product.

11. The microfluidic chip according to claim 7, wherein,

The micro through holes are through holes with high depth-to-width ratio;

the surface of the microporous layer is provided with a first hydrophobic area, the inner wall of the micro-through hole is provided with a hydrophilic area, the first chip bottom plate is provided with a second hydrophobic area at the position of the micro-flow channel, and the first chip upper cover is provided with a third hydrophobic area at the position of the sample injection hole.

12. A microfluidic chip according to claim 1, wherein,

The microfluidic channel is arranged at the top of the micro through hole in the chip shell, and is suitable for the sample and the sealing oil to sequentially pass through the top of the micro through hole;

The chip shell can further comprise a second chip upper cover and a second chip bottom plate, wherein the second chip upper cover is matched with and connected with the second chip bottom plate, so that a second mounting cavity is formed between the second chip upper cover and the second chip bottom plate, the micro-pore layer is arranged in the second mounting cavity, the micro-flow channel is formed between the micro-pore layer and the second chip upper cover, and a second sealing flow channel is formed between the micro-pore layer and the second chip bottom plate;

The sample is introduced into the micro-flow channel through the sample injection hole and is separated and loaded at the top position of the micro-porous layer, and the sealing oil flows into the second sealing flow channel from the micro-flow channel and is fully sealed to the micro-porous layer.

13. The microfluidic chip according to claim 12, wherein,

A second base plate is arranged on the second chip upper cover and close to the top of the second mounting cavity, and a micro-flow hole is formed in the second base plate at the top of the micro-through hole so as to form the micro-flow channel;

Or, the second chip upper cover is provided with the second backing plate at the top and bottom positions close to the second mounting cavity, and the second backing plate is provided with a micro-flow hole at the micro-through hole position to form the micro-flow channel or the second sealing flow channel.

14. The microfluidic chip according to claim 13, wherein the microfluidic chip comprises,

When the second chip upper cover is only provided with a second base plate near the top of the second mounting cavity, the second chip bottom plate is provided with a second micro-groove matched with the micro-flow hole so as to form the second sealing flow channel;

the second micro flow groove and one side of the micro flow hole far away from the sample injection hole are respectively provided with a second communication area, and the second communication areas are suitable for being mutually communicated without being blocked by the micro-porous layer.

15. A microfluidic system employing a microfluidic chip according to any one of claims 1-14, comprising: a plurality of the microfluidic chips;

and a plurality of microfluidic chips are connected.

16. A method of manufacturing a microfluidic chip, for preparing a microfluidic chip according to any one of claims 1-14, comprising the method steps of:

Firstly, adding the sample into the sample injection hole, and then adding the sealing oil into the sample injection hole;

applying positive pressure to the sample injection hole, wherein the sealing oil under the positive pressure pushes the sample into the micro-flow channel;

the sample flows through the microporous layer along the microfluidic channel, and is divided and sucked into the micro-through holes under the capillary force of the micro-through holes on the microporous layer;

The sealing oil continuously pushes the sample to flow along the micro-flow channel, the sample is further sucked by the micro-through holes at the front part of the flow direction, and the sealing oil cleans the residual sample on the inner wall of the micro-flow channel;

and the sealing oil continuously advances forward and enters the top of the microporous layer, fills the inside of the chip shell and fully seals the microporous layer so as to finish the preparation of the microfluidic chip.