A double-valve column structure for liquid release without cross-contamination

Abstract

The present invention discloses a double-valve column structure for liquid release without cross-contamination, which relates to the field of medical in vitro diagnostic and analytical instruments. By optimizing the structural design, a solution with a simpler structure is adopted to achieve the same or even better functions without adding more production processes, which can ensure the stability of liquid storage, the success rate of release, prevent liquid from contacting the valve column, eliminate cross-contamination, and is less affected by the characteristics of the elastic cover sheet layer and the height of the valve column. The double-valve column structure includes a partition wall provided between a liquid storage pool and a liquid buffer pool, at least two valve columns penetrating the partition wall, and a diversion blind groove opened on the top surface of the partition wall, and the diversion blind groove is staggered from the valve column. The risk of liquid leakage from the gap between the valve column and the valve hole is greatly reduced, and at the same time, the release performance is less affected by the characteristics of the elastic cover sheet layer and the height of the valve column, and the success rate of liquid transfer can be improved.

Description

Technical Field

[0001] The present invention relates to the field of medical in vitro diagnostic and analysis instruments, and particularly to the field of point-of-care testing (POCT) using microfluidic chip technology. Background Art

[0002] Microfluidic chip technology has gradually developed from microarray technology and is used to integrate discontinuous processes such as sample preparation, biochemical reactions, and analytical detection into a disposable chip, realizing the overall technology from sample processing to result detection. Due to its characteristics of miniaturization, automation, integration, and portability, this technology has been rapidly popularized and applied in the field of point-of-care testing (POCT).

[0003] For example, in 1969, Anderson et al. reported a centrifugal detection analyzer. It designed samples and reagents in the center of a disc, and different centrifugal forces were generated by the rotation of a motor to make them flow into small outer chambers. During rotation, each small chamber could pass through a light source in turn to detect the reaction results, thus realizing the simultaneous analysis of multiple samples. In this technical field, the vast majority of biochemical, immunological, or nucleic acid reactions require the participation of multiple liquids, and the process of most reactions involves the successive addition of liquid reagents. Therefore, it is a very important technology to store reagents in a disposable microfluidic chip or cartridge and automatically release and add the reagents.

[0004] In existing research, liquids can be stored in ampoules and placed in a chip or reaction cartridge. Before use, the ampoules are broken by an external mechanical structure to release the stored liquids. This method is difficult to process ampoules, and the final size of the chip or reaction device is large. In addition, a special motion mechanism is required to strike the ampoules, and the broken glass debris may pierce the structural layer of the chip and block the pipeline structure. Similar to the i-STAT blood gas analyzer, the research group at the University of Freiburg used plastic or aluminum foil-sealed liquid sacs to store some reagents participating in the reaction. During use, the liquid sacs were squeezed by external pressure to contact the barbs and be punctured to release the liquid. Although this method does not produce glass debris like ampoules, the liquid sacs are also difficult to make very small, and a special puncturing mechanism and external force are required to squeeze the liquid sacs. In addition, various valve or fluid control methods have also been proposed by researchers. They include two major categories:

[0005] One is the active valve, such as the paraffin valve, laser sintering valve, etc., which can more flexibly achieve various fluid operations, but the chip processing technology involved is complex, the required supporting equipment and control are complex, and paraffin or high temperature may affect the reaction.

[0006] Second, passive valves, such as capillary valves, siphon valves, etc., can achieve valve control only through rotation speed. However, in applications involving multi-step fluid release and release after long-term liquid storage, the application of these valves is subject to certain limitations.

[0007] Therefore, it is necessary to propose a structure with simple structure, low cost, and high reliability for liquid storage and release. For example, in the Chinese invention patent application with publication number CN 106195321 A, a liquid storage pool is arranged in the chip, and a connection through groove with a valve hole in the center is arranged on the partition wall connected to the pipeline. The whole chip is covered by an elastic cover layer. During use, the valve column jacks up the elastic cover layer near the valve hole upwards, so that a flow-through gap is formed on the partition wall between the elastic cover layer and the valve hole; and under the action of centrifugation, the liquid is released from the storage pool to the metering pool. The mechanical tray where the valve column is located is a reusable component.

[0008] This solution is relatively simple and reliable. In order to improve the reliability of liquid release, a through groove with an arc-shaped cross section for connection is proposed to be arranged on the partition wall in this patent application; further, in order to avoid cross-contamination between chips, this patent application proposes to cover the back surface of the structural layer with a second elastic cover layer, or to arrange a plunger with sealed filling in the valve hole. However, in actual implementation of this solution, some new challenges are also encountered, and new ideas and solutions need to be designed for adjustment and improvement.

[0009] Specifically:

[0010] The valve column solution in this patent application mainly sets a partition wall between the liquid storage pool and the liquid metering pool to confine the liquid within the partition wall; a valve hole penetrating the two side planes of the structural layer is arranged on the partition wall, and when the liquid is released, the elastic cover layer is jacked up from the position of the valve hole, and a flow-through gap is formed around the valve hole.

[0011] Therefore, when the liquid is released, the liquid will flow through the two sides and around the valve column, and there are the following defects to be improved:

[0012] First, the valve column is a reusable structure. When the liquid is released, it will contact the valve column. If the top and surrounding of the valve column are not clean, it may cause cross-contamination of the liquid; at the same time, there may also be a small amount of liquid remaining on the top of the valve column, causing cross-contamination to subsequent chip measurements;

[0013] Second, it is required that the outer peripheral surface of the valve column is in sealed cooperation with the inner peripheral surface of the valve hole. If the gap between the valve hole and the valve column is too large, there is a risk of liquid leaking from the gap between the valve column and the valve hole;

[0014] III. To balance the effectiveness of the balanced seal and the success rate of liquid release, a communication through-channel with an arc-shaped cross-section needs to be provided at the valve hole position to increase the pre-restoring force of the elastic cover layer. This arc-shaped depression increases the difficulty of chip processing and packaging, and it needs to be used in conjunction with an elastic cover layer with a relatively high elastic modulus.

[0015] IV. The opening of the valve is greatly affected by the thickness and elastic modulus of the elastic cover layer and the viscosity of the glue, and the allowable error of the valve post height is relatively small. Therefore, the material and processing costs of the elastic cover layer and the chip tray are increased.

[0016] Among them, considering the above-mentioned problem of cross-contamination caused by avoiding contact with the valve post during liquid release, two solutions are also proposed in this patent application, but there are still defects in actual practice. Specifically:

[0017] One is the solution of "single valve post" combined with "plunger". A plunger is arranged in the valve hole in contact with the liquid to avoid direct contact and cross-contamination. However, in practice, the plunger is relatively small, and the process cost of embedding it into the chip during production is high, resulting in an increase in the overall cost.

[0018] The other is the solution of "single valve post" combined with the "second elastic cover layer" on the back. A "second elastic cover layer" is added between the valve post and the first cover layer to avoid direct contact and cross-contamination. However, in practice, the second elastic cover layer needs to have a large deformation amount, and the material selection is difficult and the die-cutting process is relatively complex, resulting in a relatively high overall cost.

[0019] In summary, the field needs a liquid release solution that can avoid contact between the valve post and the liquid, eliminate cross-contamination, is less affected by the characteristics of the elastic cover layer and the height of the valve post, and has low processing difficulty and high success rate. Summary of the Invention

[0020] In view of the above problems, the present invention proposes a double-valve post structure for liquid release without cross-contamination. By optimizing the structural design, a solution with a simpler structure is adopted to complete the same or better functions without adding more production processes, which can ensure the stability of liquid storage, the success rate of release, prevent liquid from contacting the valve post, eliminate cross-contamination, and is less affected by the characteristics of the elastic cover layer and the height of the valve post.

[0021] The technical solution of the present invention is as follows: the double valve column structure is arranged between the liquid storage tank 11 and the liquid buffer tank 13 on the structural layer 1, and the double valve column structure includes a partition wall 16 arranged between the liquid storage tank 11 and the liquid buffer tank 13, at least two valve columns 34 penetrating the partition wall 16, and a guide blind groove 15 opened on the top surface of the partition wall 16, the guide blind groove 15 is staggered with the valve column 34, one end of the guide blind groove 15 is connected to the liquid storage tank 11, and the other end extends to the middle of the top surface of the partition wall 16 and is separated by the partition wall to form a disconnected blind pipeline, and the blind end and the valve hole are distributed on a similar centrifugal radius;

[0022] The liquid storage tank 11 , the isolation wall 16 , and the liquid buffer tank 13 are covered by the elastic cover layer 2 . When the valve column 34 moves relative to the isolation wall 16 , it extends upwards out of the isolation wall 16 to lift up the elastic cover layer 2 , or retracts downwards into the isolation wall 16 .

[0023] Furthermore, the liquid storage tank 11 and the liquid buffer tank 13 are both opened on the top surface of the structural layer 1 and are arranged in sequence from the inside to the outside, forming a separation wall 16 between the liquid storage tank 11 and the liquid buffer tank 13;

[0024] The structural layer 1 is provided with valve holes 14 corresponding to the valve posts 34 one by one. The valve holes 14 penetrate the isolation wall 16 , and the valve posts 34 are slidably accommodated in the valve holes 14 .

[0025] As an optimization, the valve posts 34 have two, and the center line of the guide blind groove 15 coincides with the perpendicular midline of the connection line of the two valve posts.

[0026] Furthermore, one end of the blind diversion groove 15 close to the liquid buffer pool 13 is a blind end, and the distance between the blind end and the liquid buffer pool 13 is smaller than the distance between the blind end and the nearest valve hole.

[0027] Furthermore, the isolation wall 16 includes a long channel wall and a columnar valve hole wall, and the diversion blind groove 15 is opened on the top surface of the channel wall, forming an isolation wall contraction area 141 on both sides of the channel wall;

[0028] The valve hole 14 is opened in the valve hole wall, one side of the valve hole wall is connected to the channel wall, and the valve hole wall is located next to the blind end of the diversion blind groove 15. A valve column isolation wall notch 142 is also opened at the connection between the valve hole wall and the channel wall.

[0029] Furthermore, a partition wall end notch 143 between two valve hole walls is provided at the connection between the channel wall and the liquid buffer tank 13 , and a partition wall end step 145 is provided in the partition wall end notch 143 .

[0030] Furthermore, the height of the bottom of the diversion blind groove 15 gradually decreases from the side where the liquid storage pool 11 is located.

[0031] For further optimization, the tops of the two valve posts 34 have a height difference.

[0032] Furthermore, the structural layer 1 is a sheet-shaped microfluidic chip, and the microfluidic chip is circular, fan-shaped or triangular.

[0033] Furthermore, all the valve posts 34 are fixedly connected to the chip tray 3 below the structural layer 1, and the tray 3 can be reused;

[0034] When liquid is released, the structural layer 1 and the elastic cover layer 2 are integrally placed on the tray, so that the valve posts 34 pass through the valve holes 14 and lift the elastic cover layer 2 to cover the valve holes 14 and the surrounding parts, thereby forming a flow-through gap between the elastic cover layer and the isolation wall, conducting the blind end of the diversion blind groove 15, and the flow-through gap is separated from the valve posts 34;

[0035] When the liquid release ends, the structural layer 1 and the elastic cover layer 2 are integrally lifted, so that the valve posts 34 retract into the valve holes 14, the elastic cover layer 2 resets, and the liquid is cut off at the blind end of the diversion blind groove 15.

[0036] Furthermore, a liquid metering pool 12 and a liquid overflow pool 18 are provided on the top surface of the structural layer 1 outside the liquid buffer pool 13. The liquid metering pool 12 and the liquid buffer pool 13 are kept in communication through a plurality of communication grooves 122 provided on the structural layer 1. A communication groove variable diameter area 121 is provided at the notch where one or more of the communication grooves 122 communicate with the liquid metering pool 12. The liquid metering pool 12 and the liquid overflow pool 18 are kept in communication through an overflow channel 17 provided on the structural layer 1.

[0037] Furthermore, a centrifugal positioning hole 10 is provided on the structural layer 1, and a chip positioning post 30 adapted to the centrifugal positioning hole 10 is fixedly connected to the chip tray 3.

[0038] The present invention adopts valve posts arranged on both sides of the flow path after liquid release; these valve posts lift the parts of the elastic cover layer that cover and seal the valve holes, and then lift the elastic cover layer 2 between the two valve holes upward, and a flow-through gap is formed in the middle of the two valve posts. Finally, the liquid storage pool, the liquid buffer pool and the liquid metering pool are connected; a diversion blind groove is provided along the perpendicular bisector of the connection line of the two valve posts, which can limit the liquid release to only flow along the central gap. The liquid in the microfluidic chip is released from the center to the outside under the action of centrifugal force through the pipe gap in the center of the valve posts.

[0039] The present invention first avoids the problem of cross - contamination when the liquid is released and contacts the valve post. In this solution, when the liquid is released, the liquid flow passes through the center of the bilateral valve posts, avoiding cross - contamination caused by contact with the valve posts. Moreover, since there is no liquid contact with the valve posts and valve holes, the risk of liquid leakage from the gaps between the valve posts and valve holes is greatly reduced. At the same time, the release performance is less affected by the characteristics of the elastic cover layer and the height of the valve post, which can improve the success rate of liquid transfer.

[0040] The present invention pre - defines the flow path of liquid release by setting diversion blind grooves on the partition wall. At the same time, valve posts are arranged on both sides of the sealed end of the diversion blind groove. During use, the valve posts on the left and right sides simultaneously push up the elastic cover layer, opening the blind end of the originally sealed diversion blind groove, thus realizing the connection of the diversion blind groove.

[0041] During the liquid transfer process of the present invention, the liquid flows down from the diversion blind groove in the center of the double valve posts without touching the valve posts, thus avoiding the cross - contamination problem caused by direct contact between the valve posts and the liquid, and also eliminating the liquid leakage problem caused by the gaps between the valve posts and valve holes. In the double - side top - film valve opening, there is no need to design a depression at the valve hole, which also reduces the requirements for the height and diameter of the valve posts, the viscosity, thickness, and elastic modulus of the elastic cover layer, and reduces the manufacturing cost of the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic diagram of the implementation mode of this case,

[0043] Figure 2 is a top - view of the structure in this case,

[0044] Figure 3 is a three - dimensional Figure 1 ,

[0045] Figure 4 is a three - dimensional Figure 2 ,

[0046] Figure 5 is a three - dimensional Figure 3 ,

[0047] Figure 6 is a structural schematic diagram of the chip positioning posts and valve posts in this case Figure 1 ,

[0048] Figure 7 is a structural schematic diagram of the chip positioning posts and valve posts in this case Figure 2 ,

[0049] Figure 8 is a reference diagram of the use state of the valve post in this case,

[0050] Figure 9 is a diagram showing the cooperation relationship between the structural layer and the elastic cover layer in this case,

[0051] Figure 10 It is a cross-sectional view of the position where the diversion blind groove is located during liquid release in this case.

[0052] Figure 11 It is a cross-sectional view of the position where the step at the end of the partition wall is located during liquid release in this case.

[0053] In the figure, 1 is the structural layer, 10 is the chip positioning hole, 11 is the liquid storage pool, 12 is the liquid metering pool, 13 is the liquid buffer pool, 14 is the valve hole, 15 is the diversion blind groove, 16 is the partition wall, 17 is the overflow channel, 18 is the liquid overflow pool, and 19 is the air pressure balance pipeline.

[0054] 112 is the injection hole isolation column, 116 is the injection hole, 121 is the variable diameter area of the communication groove, 122 is the communication groove, 123 is the outlet of the communication groove, 141 is the constriction area of the partition wall, 142 is the notch of the valve column partition wall, 143 is the notch at the end of the partition wall, 145 is the step at the end of the partition wall, 151 is the micro pipeline of the diversion blind groove, and 152 is the end of the diversion blind groove.

[0055] 2 is the elastic cover layer, 25 is the unbonded area between the elastic cover layer and the structural layer, and 29 is the air pressure balance through hole.

[0056] 3 is the chip tray, 30 is the chip positioning post, and 34 is the valve post. Specific implementation mode

[0057] To clearly illustrate the technical features of this patent, the following will elaborate on this patent in detail through specific implementation modes and in combination with its attached drawings.

[0058] As shown in Figures 1-11 this invention includes the following:

[0059] The structural layer 1, the structural layer 1 is a sheet-shaped microfluidic chip, the bottom surface of the structural layer 1 is a plane, and a liquid storage pool 11, a liquid buffer pool 13, and a liquid metering pool 12 are arranged on the top surface. The liquid storage pool 11 and the liquid buffer pool 13 are isolated by a common T-shaped wall. A plurality of valve holes 14 penetrating both side planes of the structural layer 1 are arranged in the partition wall 16. The microfluidic chip can be a circular chip, or a fan-shaped, triangular, etc. chip.

[0060] The upper plane of the structural layer 1 is provided with a liquid storage tank 11, a liquid buffer tank and a liquid quantitative tank 12. The liquid storage tank 11 and the liquid buffer tank 13 are isolated by a common isolation wall 16. A diversion blind groove 15 is provided in the upper plane of the isolation wall 16. Two valve holes 14 penetrating the two side planes of the structural layer 1 are axially symmetrically provided along the diversion blind groove 15; one end of the diversion blind groove 15 is connected to the liquid storage tank 11, and the other end extends to the liquid buffer tank 13, but does not penetrate the isolation wall 16, forming a diversion blind groove 15 with a certain depth.

[0061] The liquid storage tank 11, liquid buffer tank 13, liquid quantitative tank 12, isolation wall 16, guide blind groove 15 and valve column 34 can be independently arranged on the structural layer as a set, or can be symmetrically arranged in multiple sets on the structural layer, the latter can realize the sampling and detection of more samples.

[0062] The diversion blind groove 15 is located on the partition wall between the two pools and is set along the vertical line connecting the valve columns on both sides; one end is connected to the liquid storage pool, and the other end extends to the liquid buffer pool and is separated by the partition wall. In the sealed state, the two ends of the diversion blind groove 15 are not connected, and a disconnected blind pipe is formed in the part close to the liquid buffer pool 13, and the blind end is located between the valve holes 14. When the liquid needs to be released, the elastic cover layer is lifted up by the valve column, and the blind end of the diversion blind groove 15 is located in the area where the elastic cover layer is propped up. At the blind end of the diversion blind groove, the structural layer and the elastic cover layer form a gap, thereby connecting the liquid storage pool 11 and the liquid buffer pool 13; after the diversion blind groove is connected, the liquid can flow from the tail end of the storage pool 11, along the diversion blind groove 15 to the liquid buffer pool 13 under the action of centrifugal force, and enter the liquid quantitative pool 12.

[0063] The valve hole 14 is located in the partition wall 16 between the liquid storage tank 11 and the liquid buffer tank 13, and is symmetrically located on both sides of the diversion blind groove 15, and is a through hole that penetrates the planes on both sides of the structural layer; the valve column 34 can push up the elastic cover layer 2 near the valve hole 14. The number of valve holes 14 can be 2-6, and preferably, the number of valve holes is 2.

[0064] The valve column 34 is located on the chip tray 3, and the arrangement of the valve column 34 corresponds to the shape, quantity and position of the valve hole 14. In the sealed state, the structural layer 1 and the elastic cover layer 2 are tightly fitted; when liquid needs to be released, the valve column 34 passes through the valve hole 14, and lifts and opens the valve hole 14 and the elastic cover layer 2 glued and sealed around it, so that a gap is formed between the structural layer 1 and the elastic cover layer in this area.

[0065] The liquid storage pool 11 is arranged near the inner diameter of the centrifuge, and is used to pre-store the solution required for the biochemical reaction and release it by the valve column and centrifugal force when needed. The elastic cover layer 2 is elastically attached to the surface of the structural layer 1, and there is an unbonded area 25 between the elastic cover layer and the structural layer on the channel walls where the liquid storage pool 11, the liquid buffer pool 13 and the diversion blind groove 15 are located.

[0066] On the plane of the structural layer 1 opposite to the elastic cover layer 2, there is also a sampling hole 116 communicated with the liquid storage pool 11 for injecting the liquid in the liquid storage pool. The sampling holes can be set to more than 2, preferably 2; the sampling ports can be isolated by the sampling hole isolation columns 112. When injecting liquid, it enters from one sampling hole, and the corresponding internal air is discharged from the other sampling hole.

[0067] Outside the liquid metering pool 12, a liquid overflow pool 18 can also be arranged; it is used to store the excess liquid after quantification. When the liquid is released after the double valve columns are opened, it preferentially fills the metering pool 12 after entering the buffer pool and overflows to the overflow pool after the metering pool is full, so as to achieve accurate quantification of the liquid. The liquid metering pool 12 and the liquid buffer pool 13 are kept in communication through a plurality of communication grooves 122 opened on the structural layer 1. A communication groove diameter-changing area 121 is opened at the notch of one or more of the communication grooves 122 communicated with the liquid metering pool 12. The liquid metering pool 12 and the liquid overflow pool 18 are kept in communication through an overflow channel 17 opened on the structural layer 1. An air pressure balance pipeline 19 is also communicated beside the liquid buffer pool 13 and the liquid overflow pool 18, and an air pressure balance through hole for communicating with the air pressure balance pipeline 19 is opened on the elastic cover layer 2;

[0068] Centrifugal positioning holes 10 are also arranged at other positions on the structural layer 1. Chip positioning columns 30 adapted to the centrifugal positioning holes 10 are fixedly connected to the chip tray 3. The centrifugal positioning holes can be located outside or inside the liquid metering pool and the liquid storage pool, and are used to realize the function of accurate positioning of the tray and assist the valve column to jack up the elastic cover layer upward.

[0069] The whole structural layer 1 is covered by an elastic cover layer 2. When the liquid is released, the valve column 34 jacks up the elastic cover layer 2 above and around the valve hole 14 upward, so that a flow gap is formed on the lower surface of the elastic cover layer 2 and the partition wall between the two valve holes 14; under the action of centrifugal force, the liquid is released from the storage pool to the metering pool. This scheme is simple and reliable, avoiding the direct contact between the liquid and the valve column.

[0070] The elastic cover sheet layer is attached to the structure layer 1 and covers and seals structures such as the liquid storage pool, the diversion blind groove, the buffer pool, the liquid metering pool, and the valve hole, forming a closed microfluidic pipeline; when liquid release is required, each valve post can be inserted into the corresponding valve hole to lift the part of the elastic cover sheet layer covering the valve hole and its surroundings, thereby forming a connected flow gap.

[0071] The elastic cover sheet layer 2 is attached to the structure layer 1 and covers and seals the liquid storage pool 11, the liquid metering pool 12, and the valve hole 14. The valve hole 14 can be hermetically inserted with a valve post 34 for lifting the part of the elastic cover sheet layer 2 covering the valve hole 14.

[0072] When the valve post lifts the film, the diversion blind groove is opened, and the liquid storage pool is communicated with the lower metering area. However, since the diversion blind groove is the only connecting pipeline and a capillary micro-pipeline with capillary force is formed by designing the pipeline width, the path of fluid release will be restricted.

[0073] Experiments verified that the channels formed at the blind ends of the blind grooves after the two valve posts are lifted are small. When the centrifugal force is insufficient, it will be difficult for the liquid to flow out. When the centrifugal speed < 1500 rpm, the liquid in the liquid storage pool is affected by air pressure and cannot flow down. When the centrifugal speed > 1500 rpm, the centrifugal force > the force received by the angular acceleration. Therefore, the angle between the flowing direction of the liquid and the centrifugal force < 45°. Therefore, when the distance between the blind end of the diversion blind groove and the metering area is less than the distance between the blind end of the diversion blind groove and the valve hole, the liquid will not touch the valve hole.

[0074] The distance between the two valve holes, especially the minimum distance (non-center distance) between the two valve holes, will affect the height of the valve post required to open the valve. When the valve hole spacing increases, the height of the valve post for opening the valve increases. The height of the valve post can be set slightly higher than the thickness of the chip, for example, 0.3 - 1 mm, preferably 0.4 - 0.8 mm, and more preferably the height of the valve post is 0.55 - 0.7 mm higher than the thickness of the chip.

[0075] The valve hole and the diversion blind groove are also separated by a partition wall, which is arranged on the surface of the partition wall in contact with the elastic cover sheet layer. The distance from any valve hole to the edge of the diversion blind groove can be 0.4 - 1.2 mm, preferably 0.7 - 1 mm, and more preferably 0.85 mm.

[0076] The design of the valve post diameter is very important for the success rate of valve release. If the valve post is too thick, the resilience is large. When the two valves are opened, the liquid cannot be controlled into a line, and liquid flow bifurcation or even contact with the valve post will occur; if the valve post is too thin, the elastic cover sheet layer at the end of the diversion blind groove cannot be separated, and the valve cannot be opened. The valve post diameter is 1 - 3 mm, preferably 1.5 - 2 mm. The preferred cross-section of the valve post is circular, but it is not limited to a cylinder, and can also be a conical shape, an elliptical cylinder, or a square column.

[0077] Preferably, the two sides of the valve post can also be designed with different heights, and the deflection direction of liquid release can be adjusted by the height difference between the two sides, the distance between the valve posts, and the direction of centrifugal rotation.

[0078] Preferably, in the above microfluidic chip, the horizontal cross-sections of multiple valve posts are circular, semi-circular or oblong.

[0079] An isolation wall shrinkage area 141 and a valve post isolation wall notch 142 are provided around the valve post to separate the upper part of the diversion blind groove from the valve post, reducing the magnitude of the force required to open the valve; and when the valve post is lifted upward, the blind end at the lower part of the diversion blind groove is preferentially opened, while its upper part remains in a sealed state. Further, in order to reduce the force required to open the valve, an isolation wall end notch 143 and an isolation wall end step 145 are also provided at the end of the isolation wall, reducing the sealing area at the end of the diversion blind groove. The isolation wall end notch 143 also serves as a drainage function, enabling the liquid to flow vertically or at a small angle under the action of centrifugal force, avoiding contact with the valve post.

[0080] One end of the diversion blind groove is connected to the liquid storage pool and the other end extends towards the liquid buffer pool; preferably, the width of the diversion blind groove is 0.2 mm; the depth of the cross-section of the diversion blind groove is 0.15 - 0.25 mm. The depth of the diversion blind groove 15 on the side close to the liquid storage pool 11 is 0.15 mm, and the depth on the side close to the liquid buffer pool 13 is 0.25 mm.

[0081] The cross-section of the diversion blind groove is rectangular or square, and the aspect ratio of the rectangle can be any value from 1:2 to 1:5, where the width can be any value from 0.1 - 0.5 mm; the cross-sectional dimensions of the diversion blind groove can be set correspondingly and segmentally differently according to the rotation speed and flow resistance of liquid release, for example, set as pipes with different lengths and widths in multiple segments.

[0082] Regarding the thickening and deepening of the above diversion blind groove, a thin diversion blind groove channel. It is preferably divided into two sections, 0.15 - 0.25 mm (preferably 0.18 mm) near the centrifugal center end, and 0.25 - 0.8 mm (preferably 0.3 mm) near the blind end (away from the far center end). The preferred width of the diversion blind groove: 0.1 - 1 mm, preferably 0.15 - 0.4 mm, more preferably 0.2 - 0.3 mm (preferably 0.2 mm). More specifically, the top part of the diversion blind groove channel is shallower, and the part near the valve hole is deeper.

[0083] The blind end of the diversion blind groove extends to the connection line of the centers of two valve holes, and its positional relationship with the connection line of the valve hole centers is that the diversion blind groove is located on the perpendicular line of the connection line of the valve hole centers. Preferably, the diversion blind groove is located on the perpendicular bisector of the connection line of the valve hole centers.

[0084] The positional relationship between the blind end and the center line connecting the valve holes to the buffer pool is as follows: for the center line connecting the centers of the two valve holes (point A), and the midpoint between the lowest point of the blind end of the diversion blind groove (the point farthest from the center of the centrifuge) and the closest point to the blind end of the buffer pool (point B), the distance between point A and point B is less than 1.5 - 3 mm. Preferably, point B is lower than point A (in this case, the liquid is not likely to touch the valve post), and the distance between the two points is <0.8 mm, and more preferably, it can be set to 0.5 mm. The closest distance between the blind end of the diversion blind groove and the buffer pool, which is also the narrowest width of the partition wall, can be 0.4 - 1.2 mm, preferably 0.5 - 0.9 mm, and more preferably 0.6 mm.

[0085] On the other side plane of the structural layer facing away from the elastic cover layer, there is also a sampling hole 116 communicating with the liquid storage pool 11. This sampling hole is used to inject liquid into the liquid storage pool of the chip after the structural layer and the elastic cover layer are sealed to form a microfluidic chip; and it is sealed with tape.

[0086] The elastic cover layer is transparent and is an elastic layer composed of a polymer material or an elastic film structure composed of a metal film. The thickness of the elastic cover layer 2 is 0.01 mm to 2 mm. One side of the elastic cover layer is a single-sided adhesive bonding layer.

[0087] The material of the structural layer is any one or any combination of polymer materials, glass, or metals.

[0088] In another embodiment of the present application,

[0089] The partition wall 16 includes a strip-shaped channel wall and a columnar valve hole wall. The diversion blind groove 15 is opened on the top surface of the channel wall, forming a partition wall contraction area 141 on both sides of the channel wall;

[0090] The valve hole 14 is opened in the valve hole wall. One side of the valve hole wall is integrated with the channel wall, and the valve hole wall is located beside the blind end of the diversion blind groove 15. There is also a valve post partition wall notch 142 opened at the connection between the valve hole wall and the channel wall. The partition wall around the valve post is provided with a partition wall contraction area 141 and a valve post partition wall notch 142, which are used to separate the upper part of the diversion blind groove and the valve post, reducing the force required to open the valve; and when the valve post is lifted upward, it preferentially opens the blind end at the lower part of the diversion blind groove, while its upper part remains in a sealed state.

[0091] After actual testing, when controlling the rotation speed so that the liquid flows above the blind end of the diversion blind groove, the fluid path is a single path without bifurcation. For example, when the liquid is released at 5000 rpm, it is a single path. This setting reduces the risk of the liquid touching the valve post.

[0092] In this structural design, when the rotational speed is < 3000 rpm, the liquid does not flow; when it is 3300 rpm, the liquid flows down slowly drop by drop; when it is 5000 rpm, the liquid flows down quickly. The controllable release of the fluid can be achieved.

[0093] Furthermore, at one end of the channel wall facing the liquid buffer pool, there is a notch 143 at the end of the partition wall between the two valve hole walls, and a step 145 at the end of the partition wall is provided in the notch 143 at the end of the partition wall. The notch 143 at the end of the partition wall and the step 145 at the end of the partition wall reduce the sealing area at the end of the diversion blind groove. The notch 143 at the end of the partition wall also plays a role in guiding the flow, enabling the liquid to flow vertically or at a small angle under the action of centrifugal force, thus avoiding contact with the valve post.

[0094] In this way, with the help of the notch 142 of the valve post partition wall, the separation between the valve hole wall and the channel wall can be more complete. If the liquid does not flow along the extension line of the diversion blind groove but along an arc, the existence of the notch 143 at the end of the partition wall can also play a role in guiding the flow, thereby guiding the liquid away instead of contacting the valve post.

[0095] In this structural design, when the rotational speed is < 1000 rpm, the liquid does not flow down; when it is 4100 rpm, the liquid flows down stably for the first time; when the rotational speed drops below 1500 rpm, the liquid stops flowing. When the rotational speed rises to 4900 rpm, the liquid flows down stably for the second time. The multiple release of the liquid can be achieved.

[0096] In this case, through the design of the diversion blind groove and the two valve posts on both sides, the success rate of valve opening for the second time reaches more than 99%, the release rotational speed range is stable, and the probability of contact between the liquid and the valve post is minimized.

[0097] In this case, the liquid will not contact the valve post, avoiding the risks of cross - contamination and liquid leakage from the gap between the valve hole and the valve post. The processing technology and packaging scheme adopted are simple, the success rate and reliability of liquid release are good, and there is no need to set a through - groove with an arc - shaped cross - section at the valve hole position. The material selection standard of the elastic cover layer is reduced, the influence of the thickness, elastic modulus of the elastic cover layer and the viscosity of the glue on the opening of the valve is reduced, and the tolerance of the valve post height is increased. Therefore, the material selection standard and cost of the materials are reduced.

[0098] In the double - valve - post structure proposed in this case, the liquid does not contact the valve post during valve opening and liquid release, and flows down from the diversion blind groove between the valve posts. Therefore, the problem of cross - contamination caused by direct contact between the valve post and the liquid is avoided, and the problem that the liquid may leak from the gap between the two when the valve post diameter is smaller than the valve hole diameter is also eliminated.

[0099] When liquid release is required in this case, the sealed microfluidic chip is placed on the tray, so that the valve hole is inserted into the valve post, and the elastic cover layer is lifted to cover the valve hole and its surrounding parts, forming a flow gap in the center of the bilateral valve posts. The liquid flows out along the diversion blind groove, avoiding the contact between the liquid and the reusable valve post.

[0100] In this case, the liquid flow resistance is mainly affected by the diversion blind groove. Even if the height of the valve post is very high, it will not cause the liquid flow rate to be too fast. Therefore, the height requirements for the bilateral valve posts are relatively low. This avoids the problem that the height and diameter requirements for the valve post in the aforementioned single valve post solution are relatively high.

[0101] For existing chips, even if a depression is provided at the valve hole, for example, with a depth of 0.5 mm, and if the tray valve post is too low or too thin, the elastic cover layer may not be able to be pushed open; for a single valve post plane without a depression, it is difficult to push open the elastic cover layer. In addition, for a plane without a depression but with a very narrow width of the fitting edge around the valve hole, the elastic cover layer cannot adhere, so the valve opening success rate of the single valve post is relatively low.

[0102] The depression in the original single valve post structure will cause the film attached to the front of the chip to be not easily adhered, and the viscosity of the film needs to be increased to achieve a reliable sealing success rate. In the double-column valve structure described in this application, a depression communication groove does not need to be designed at the valve hole position to ensure the success rate of liquid release, reducing the viscosity requirements for the elastic cover layer.

[0103] There are many specific implementation ways of the present invention. The above are only the preferred implementation manners of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements can still be made, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. A double-valve column structure for liquid release without cross-contamination, characterized in that, the double-valve column structure is arranged between a liquid storage pool (11) and a liquid buffer pool (13) on a structural layer (1). The double-valve column structure includes a partition wall (16) arranged between the liquid storage pool (11) and the liquid buffer pool (13), at least two valve columns (34) penetrating the partition wall (16), and a diversion blind groove (15) opened on the top surface of the partition wall (16). The diversion blind groove (15) is staggered with the valve columns (34). One end of the diversion blind groove (15) is in communication with the liquid storage pool (11), and the other end extends to the middle of the top surface of the partition wall (16) and is blocked by the partition wall to form a disconnected blind pipe; the liquid storage pool (11), the partition wall (16), and the liquid buffer pool (13) are covered by an elastic cover sheet layer (2). When the valve columns (34) move relative to the partition wall (16), they protrude upward from the top of the partition wall (16) to lift the elastic cover sheet layer (2), or retract downward into the partition wall (16); both the liquid storage pool (11) and the liquid buffer pool (13) are opened on the top surface of the structural layer (1) and are arranged in sequence from inside to outside, and a partition wall (16) is formed between the liquid storage pool (11) and the liquid buffer pool (13); valve holes (14) corresponding to the valve columns (34) one by one are opened on the structural layer (1). The valve holes (14) penetrate the partition wall (16), and the valve columns (34) are slidably accommodated in the valve holes (14); the partition wall (16) includes a strip-shaped channel wall body and a columnar valve hole wall body. The diversion blind groove (15) is opened on the top surface of the channel wall body, and partition wall contraction areas (141) are formed on both sides of the channel wall body; the valve holes (14) are opened in the valve hole wall body. One side of the valve hole wall body is integrated with the channel wall body, and the valve hole wall body is beside the blind end of the diversion blind groove (15). A valve column partition wall notch (142) is also opened at the connection between the valve hole wall body and the channel wall body; at the connection between the channel wall body and the liquid buffer pool (13), a partition wall end notch (143) located between two valve hole wall bodies is also opened, and a partition wall end step (145) is opened in the partition wall end notch (143); the tops of two valve columns (34) have a height difference.

2. A double-valve column structure for liquid release without cross-contamination according to claim 1, characterized in that, there are two valve columns (34), and the center line of the diversion blind groove (15) coincides with the perpendicular bisector of the line connecting the two valve columns.

3. A double-valve column structure for liquid release without cross-contamination according to claim 1, characterized in that, one end of the diversion blind groove (15) close to the liquid buffer pool (13) is a blind end, and the distance between the blind end and the liquid buffer pool (13) is less than the distance between the blind end and the nearest valve hole.

4. A double-valve column structure for liquid release without cross-contamination according to claim 1, characterized in that, The height of the bottom of the diversion blind groove (15) gradually decreases from the side where the liquid storage pool (11) is located.

5. A double-valve column structure for liquid release without cross-contamination according to any one of claims 1-4, characterized in that, all valve columns (34) are fixedly connected to the chip tray (3) below the structural layer (1); When liquid is released, the structural layer (1) and the elastic cover layer (2) are integrally placed on a reusable tray, so that the valve columns (34) pass through the valve holes (14) and lift the elastic cover layer (2) to cover the parts around the valve holes (14), thereby forming a flow gap between the elastic cover layer and the partition wall, conducting the blind end of the diversion blind groove (15), and the flow gap is separated from the valve columns (34); When the liquid release is completed, the structural layer (1) and the elastic cover layer (2) are integrally lifted, so that the valve columns (34) retract into the valve holes (14), the elastic cover layer (2) resets, and the liquid is cut off at the blind end of the diversion blind groove (15).

6. A double-valve column structure for liquid release without cross-contamination according to any one of claims 1-4, characterized in that, a liquid metering pool (12) and a liquid overflow pool (18) are further provided on the top surface of the structural layer (1) outside the liquid buffer pool (13). The liquid metering pool (12) and the liquid buffer pool (13) are kept in communication through a plurality of communication grooves (122) provided on the structural layer (1). A communication groove variable diameter area (121) is provided at the notch where one or more of the communication grooves (122) communicate with the liquid metering pool (12). The liquid metering pool (12) and the liquid overflow pool (18) are kept in communication through an overflow channel (17) provided on the structural layer (1).

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