Multipurpose centrifugal microfluidic chip
By designing multiple liquid separation tanks and arc-shaped detection tank structures in a centrifugal microfluidic chip, combined with low speed driving, the problems of small sample detection flux and high speed cost in the prior art are solved, and high throughput, Multi-sample detection and low-cost liquid equalization and detection functions.
Patent Information
- Application Number
- CN202111467101.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-12-03
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2041-12-03
AI Technical Summary
The existing centrifugal microfluidic chips have small flux in sample detection and cannot adapt to multi-sample detection. The high-speed driving increases manufacturing cost and R&D difficulty.
A multi-purpose centrifugal microfluidic chip is designed, using a cover sheet, a hydrophobic and breathable membrane and a substrate structure. Multiple separating tanks and waste liquid tanks are set up through the geometric rotation center, and liquid equalization and detection are achieved using low rotation speed. Arc detection tank and capillary passive valve structure increase sample detection throughput and reduce manufacturing costs.
It realizes high-throughput, multi-sample detection, low-speed driving, simplifies the structure and processing process, and reduces the cost of instrument research and development and manufacturing.
Smart Images
Figure CN113967492B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to applications in the fields of biomedicine and analytical chemistry, and in particular to a multi-purpose centrifugal microfluidic chip. Background Art
[0002] In the micro-total analysis system, the equal distribution, reaction and detection of samples and reagents are mainly achieved through microfluidic chips. With the development of microfluidic technology, the driving modes of microfluidic chips mainly include pressure drive, electroosmotic drive, surface tension drive and centrifugal drive. Among them, the centrifugal drive mode uses centrifugal force to transport the sample to be tested into the chip. It has the characteristics of compact structure, wide range of applicable samples and large range of adjustable flow rate, and is widely used in the fields of biomedicine and analytical chemistry.
[0003] At present, there are many schemes for achieving liquid equal distribution by centrifugal drive, mainly in two ways: one is to use high rotation speed to achieve equal distribution of liquid in the wavy channel, such as the patent document with Chinese patent publication number CN102369443A, which discloses a centrifugal sample analysis chip, which consists of a wavy detection groove, a buffer hole and a reaction hole; the detection groove of the microfluidic chip is wavy, the channel structure is complex, the processing difficulty is large, the processing cost is high, and the reaction holes are distributed at the edge of the circular microfluidic chip, and the sample detection flux is small; because the microfluidic chip only uses one sample addition channel, the detection sample is single and cannot adapt to occasions with diversified detection samples; in addition, the microfluidic chip needs to use a higher rotation speed to drive the liquid movement, which will also increase the research and development and manufacturing costs of the instrument. The other is to use structures such as quantitative elements, sample dividing elements and siphon valves to achieve the equal distribution operation of the liquid. For example, the patent document with Chinese patent publication number CN207586245U discloses a centrifugal microfluidic chip for detecting pathogenic microorganisms. The microfluidic chip consists of a sample loading pool, a sample dividing element and a reaction element. The sample in the sample loading pool is transported to the reaction pool through the siphon valve and the sample dividing element by centrifugal force. Although the microfluidic chip can ensure the uniformity of the liquid during equal distribution, the number of reaction pools is small and the detection flux is small. It is also unable to adapt to occasions with many sample detection indicators. At the same time, the microfluidic chip often needs to be driven at multiple speeds, which greatly increases the R&D and manufacturing costs. Summary of the invention
[0004] The present invention aims to provide a multi-purpose centrifugal microfluidic chip with high throughput and diversified detection sample types, which can achieve equal distribution and detection of liquids and has low manufacturing cost.
[0005] To achieve the above purpose, the present invention can adopt the following technical solutions:
[0006] The multi-purpose centrifugal microfluidic chip of the present invention comprises a cover sheet, a hydrophobic breathable membrane and a substrate; the cover sheet, the hydrophobic breathable membrane and the substrate are stacked up and down in sequence and integrated into one by laser welding, hot pressing bonding or gluing; a rotating shaft connection structure is provided on the substrate at the geometric rotation center, a plurality of liquid separation pools are evenly distributed around the geometric rotation center, a waste liquid tank is provided on the substrate around the geometric rotation center, and the waste liquid tank is used to collect excess samples; each of the liquid separation pools is connected to the waste liquid tank through a detection tank, and the edge of the detection tank or one side thereof is connected to the waste liquid tank through a detection tank. A reaction pool is provided at the edge; a waste liquid exhaust hole, a separation pool exhaust hole and an injection hole with an upper opening structure are provided on the substrate; the separation pool exhaust hole is used to keep the air pressure in the detection tank constant during the rotation of the microfluidic chip; the separation pool exhaust hole and the injection hole are respectively connected with the separation pool, the waste liquid exhaust hole is connected with the waste liquid tank through an exhaust channel, and the orifices of the separation pool exhaust hole and the waste liquid exhaust hole are respectively sealed by the hydrophobic breathable membrane; through holes are respectively provided on the cover sheet corresponding to the positions of the rotating shaft connection structure, the injection hole, the separation pool exhaust hole and the waste liquid exhaust hole.
[0007] Preferably, the detection groove is a straight groove or an arc groove, and a capillary passive valve is provided at the junction of the detection groove and the liquid separation pool; the capillary passive valve is used to prevent liquid from entering the detection groove when adding samples.
[0008] Preferably, the shape of the reaction pool can be a circular hole, a square hole or a waist-shaped hole, etc., which can realize the liquid storage function; the diameter of the circular hole or the width of the square hole is equal to, less than or greater than the width of the detection slot.
[0009] Preferably, the straight groove or the arc groove is arranged to be tilted in a clockwise or counterclockwise direction, that is, the tilting direction is opposite to the rotation direction of the microfluidic chip when it is working.
[0010] Preferably, the capillary passive valve is a structural valve.
[0011] Preferably, the injection hole is a conical hole matching the size of a standard pipette tip, and is covered with a flexible mold to facilitate the insertion and sealing of the standard pipette tip.
[0012] Preferably, a plurality of reaction pools are arranged in each detection tank, and the volume of each liquid separation pool is equal to 1.2 to 1.5 times the total volume of the reaction pools in the detection tank connected thereto, so as to achieve preliminary equal division of the liquid.
[0013] Preferably, the plurality of liquid separation pools are interconnected, and the planar shape of each liquid separation pool may be fan-shaped, semicircular or semi-elliptical.
[0014] The present invention uses a low rotation speed to achieve the function of equal distribution and detection of liquid, is suitable for the range of 0~500r / min, and reduces the research and development cost of the instrument used therewith. Compared with the prior art, the liquid storage tank and the liquid separation tank are combined, and the siphon valve is not used, the structure is simple, and the processing difficulty is low; and only one rotation speed is used to achieve the quantitative and equal distribution operation of the liquid, which is convenient to operate. The arc-shaped detection tank structure is adopted, and the centrifugal force during the rotation process is used to force the liquid in the detection tank to flow along the wall, so as to achieve the equal distribution operation of the liquid in the reaction tank. At the same time, compared with the straight-line detection tank arranged in the radial direction, the length of the detection tank is extended, and the throughput of the sample detection is increased. A plurality of liquid separation tanks are set to achieve the equal distribution and detection of different types of samples. The liquid separation tanks are radially distributed from the geometric rotation center of the substrate to the periphery, avoiding cross contamination between samples in the liquid separation tanks. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a schematic diagram of the axonometric structure of embodiment 1 of the present invention.
[0016] Figure 2 yes Figure 1 Schematic diagram of the structure of the substrate.
[0017] Figure 3 It is a schematic diagram of the substrate structure of Example 2 of the present invention.
[0018] Figure 4 It is a schematic diagram of the substrate structure of Example 3 of the present invention. DETAILED DESCRIPTION
[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0020] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.
[0021] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0022] In addition, the meaning of "and / or" appearing in the full text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the protection scope required by the present invention.
[0023] Embodiment 1:
[0024] like Figure 1 , 2 As shown, the multi-purpose centrifugal microfluidic chip of the present invention comprises a disc-shaped cover sheet 1, a hydrophobic breathable membrane 2 and a disc-shaped substrate 3. The cover sheet 1, the hydrophobic breathable membrane 2 and the substrate 3 are stacked up and down in sequence and are integrated by laser welding, hot pressing bonding or gluing.
[0025] Three rotating shaft connecting holes 4 are evenly distributed on the substrate 1 at the radial position set by the center point o, which are used to fix and rotate the microfluidic chip.
[0026] Twelve liquid separation pools 5 are evenly distributed around the center point o of the substrate 1. The planar shape of each liquid separation pool 5 can be fan-shaped, semicircular or semi-elliptical, and the liquid separation pools 5 are connected in sequence; of course, the liquid separation pools 5 can be arbitrarily divided and blocked into different small chambers according to the requirements of the sample type to be detected.
[0027] A waste liquid tank 7 in the shape of a ring is provided on the substrate 1 near the edge thereof, with the center o of the substrate 1 being used for collecting excess samples during the detection process.
[0028] Each liquid separation pool 5 is connected to the waste liquid tank 7 through a detection groove 8. The detection groove 8 is an arc groove arranged in a clockwise direction, which is opposite to the rotation direction (counterclockwise) of the microfluidic chip when it is working. A plurality of reaction pools 9 are arranged in the detection groove 8 at intervals along the clockwise direction. The sample detection is achieved by pre-embedding substances used for biochemical reactions, immunodiagnosis or drug sensitivity testing.
[0029] The purpose of the arc grooves arranged in a clockwise direction is:
[0030] 1. When the microfluidic chip rotates counterclockwise, centrifugal force drives the liquid to flow along the curved side wall, making it easier for the liquid to break through the tension between the detection slot 8 and the reaction pool 9 and enter the reaction pool 9; 2. It serves to extend the length of the detection slot 8 and increase the throughput of sample detection.
[0031] The curvature of the detection slot 8 can be a standard semicircular arc, an elliptical arc or an arc that conforms to the trajectory of the Archimedean spiral; the reaction pool 9 can be any shape that can realize the liquid storage function, such as a circular hole, a square hole or a waist-shaped hole; the diameter of the circular hole or the width of the square hole is equal to, less than or greater than the width of the detection slot 8.
[0032] The volume of each liquid separation pool 5 is equal to 1.2 to 1.5 times the total volume of all reaction pools 9 in the detection tank 8 connected thereto, and is used to achieve preliminary equal distribution of the liquid.
[0033] A cross-shaped capillary passive valve 10 (a straight capillary passive valve or other shapes may also be selected) is provided at the junction of the detection tank 8 and the liquid separation pool 5; the capillary passive valve is used to prevent liquid from entering the detection tank 8 when adding a sample.
[0034] The substrate 3 is provided with a waste liquid exhaust hole 11, a separation pool exhaust hole 12 and an injection hole 13 with a stepped hole structure; the separation pool exhaust hole 12 is used to maintain a constant air pressure in the detection slot 8 during the rotation of the microfluidic chip; the separation pool exhaust hole 12 and the injection hole 13 are respectively connected to the separation pool 5, and the waste liquid exhaust hole 11 is connected to the waste liquid slot 7 through the exhaust channel 6; the injection hole 13 is a conical hole that matches the size of a standard pipette tip, and a flexible mold is covered on it to facilitate the insertion and sealing of a standard pipette tip.
[0035] The diameter of the hydrophobic breathable membrane 2 matches the waste liquid exhaust hole 11 and the separation pool exhaust hole 12 of the corresponding step hole structure; during actual manufacturing, the hydrophobic breathable membrane 2 is sealed and placed in the waste liquid exhaust hole 11 and the separation pool exhaust hole 12, respectively, and then combined into one by laser welding, hot pressing bonding or gluing.
[0036] The cover sheet 1 is provided with matching through holes 4.1, 13.1, 12.1 and 11.1 at positions corresponding to the shaft connection hole 4, the injection hole 13, the liquid separation pool exhaust hole 12 and the waste liquid exhaust hole 11.
[0037] Embodiment 2:
[0038] like Figure 3 As shown, the difference between this embodiment and embodiment 1 is that the reaction pool 9 is opened at one side edge of the detection slot 8 and is connected to the detection slot 8; in this way, the width of the arc-shaped detection slot 8 can be reduced.
[0039] Embodiment 3:
[0040] like Figure 4 As shown, the difference between this embodiment and embodiment 1 is that the detection slots 8 are straight slots arranged in a clockwise direction.
[0041] like Figure 1 , 2 As shown, taking Example 1 as an example, the working process of the present invention is briefly described as follows:
[0042] Take 1 to 4 ml of sample and add it into the separation pool 5 from the injection hole 13. During the sample addition process, the gas in the sample addition chamber is discharged from the exhaust hole 12 of the separation pool. After the separation pool 5 is filled with liquid, no bubbles appear in the liquid, and the liquid fills each separation pool 5 in turn.
[0043] The microfluidic chip with the sample added is placed on a centrifugal detection platform and rotated counterclockwise for 2 to 5 seconds at a speed of 150 to 350 r / min. During the rotation, the liquid in the separation pool 5 breaks through the capillary passive valve 10 driven by the centrifugal force and enters the arc-shaped detection groove 8. Under the action of the centrifugal force, the liquid flows close to the side wall of the arc-shaped detection groove 8. When the liquid flows to the edge of the reaction pool 9, due to the influence of the surface tension of the liquid, the flow of the liquid is hindered and the liquid accumulates. As the mass of the accumulated liquid increases, the liquid breaks through the tension and enters the reaction pool 9.
[0044] The amount of liquid in the liquid separation pool 5 is greater than the total amount of liquid in all reaction pools 9 in the corresponding arc-shaped detection slot 8, and the remaining liquid to be tested flows into the waste liquid slot 7. During the centrifugation process, the gas in the microfluidic chip is discharged from the waste liquid exhaust hole 11 to ensure the balance of the air pressure in the entire microfluidic chip during rotation.
Claims
1. A multi-purpose centrifugal microfluidic chip, comprising a cover sheet, a hydrophobic breathable membrane and a substrate; the cover sheet, the hydrophobic breathable membrane and the substrate are stacked one above the other and integrated by laser welding, hot pressing bonding or gluing; wherein: A rotating shaft connection structure is provided on the substrate at the geometric rotation center, a plurality of liquid separation pools are evenly distributed around the geometric rotation center, and a circular waste liquid tank is provided on the substrate around the geometric rotation center; the plurality of liquid separation pools are interconnected, and the planar shape of each liquid separation pool is fan-shaped or semi-elliptical; each of the liquid separation pools is connected to the waste liquid tank through a detection tank, and a reaction tank is provided in the detection tank or at the edge of one side; the detection tank is a straight tank or an arc-shaped tank, and a capillary passive valve is provided at the junction of the detection tank and the liquid separation pool; the capillary passive valve is used to prevent liquid from entering the detection tank when adding samples; the straight tank or the arc-shaped tank is inclined clockwise or counterclockwise; a plurality of The reaction pools are each equal to 1.2 to 1.5 times the total volume of the reaction pools in the detection tank connected thereto, and are used to achieve preliminary equal distribution of the liquid; a waste liquid exhaust hole, a separation pool exhaust hole and an injection hole with an upper opening structure are provided on the substrate; the separation pool exhaust hole is used to keep the air pressure in the detection tank constant during the rotation of the microfluidic chip; the separation pool exhaust hole and the injection hole are respectively connected to the separation pool, the waste liquid exhaust hole is connected to the waste liquid tank through an exhaust channel, and the orifices of the separation pool exhaust hole and the waste liquid exhaust hole are respectively sealed by the hydrophobic breathable membrane; through holes are respectively provided on the cover sheet corresponding to the positions of the rotating shaft connection structure, the injection hole, the separation pool exhaust hole and the waste liquid exhaust hole.
2. The multi-purpose centrifugal microfluidic chip according to claim 1, wherein: The reaction pool is in the shape of a circular hole, a square hole, a waist-shaped hole or other shapes of holes capable of storing liquid; the diameter of the circular hole or the width of the square hole is equal to, less than or greater than the width of the detection slot.
3. The multi-purpose centrifugal microfluidic chip according to claim 1, wherein: The capillary passive valve is a structural valve.
4. The multi-purpose centrifugal microfluidic chip according to claim 1, wherein: The injection hole is a conical hole matching the size of a standard pipette tip, and a flexible film is covered on the injection hole to facilitate the insertion and sealing of the standard pipette tip.