Liquid flow channel switching structure

Abstract

The present invention discloses a liquid flow path switching structure, comprising a chip cover plate and a centrifugal rotating mechanism for driving the chip cover plate to perform centrifugal rotational motion, and further comprising a magnet, which is fixedly mounted on the outside and arranged close to the centrifugal center of the chip cover plate when performing centrifugal rotational motion; the chip cover plate is also provided with a sample injection port assembly and a selection cavity, and the lower ends of the selection cavity are respectively provided with a first liquid chamber and a second liquid chamber connected to the selection cavity. The present invention utilizes the magnetic force of the magnetic field and the direction switching of the centrifugal rotating mechanism to cause the guide block in the cavity on the chip cover plate to deflect left and right, thereby achieving the switching of the liquid flow path in the cavity, and adopts the method of switching the flow path first and then flowing in the liquid sample, which can improve the accuracy of the liquid flow path switching. At the same time, the liquid flow path switching can be achieved only by switching the direction and speed of the centrifugal rotating mechanism, which is low in cost, easy to use, and highly practical.

Description

Technical Field

[0001] The present invention relates to the technical field of microfluidic chips, and in particular to a liquid flow channel switching structure. Background Art

[0002] In microfluidic chip applications, "sample-in, answer-out" ('sample-to-answer') is a key goal for microfluidic-based point-of-care (POCT) devices. Achieving this "sample-in, answer-out" requires precise control of the flow of various liquids. When waste liquid enters the collection chamber, it can seriously interfere with experimental results. Insufficient collection of collected liquid (residue elsewhere upstream of the chip or entering the waste chamber) can affect the final test value of the microfluidic chip. Therefore, specialized structures are necessary to manipulate the flow of liquids.

[0003] The conventional method of controlling the flow direction of liquid usually uses a special valve structure, such as paraffin valve, PDMS valve and solenoid valve. However, the integrated valve structure increases the difficulty of chip processing, is not conducive to the assembly and processing of microfluidic chips, and increases the price cost of the chip. At the same time, the paraffin valve can only open or close the liquid channel, the PDMS valve requires the liquid to reach the preset pressure of the PDMS valve to work, and the solenoid valve requires an electromagnetic generator to be integrated on the microfluidic chip platform, which is complicated to install and extremely inconvenient to use. Summary of the Invention

[0004] The purpose of the present invention is to provide a liquid flow path switching structure, which utilizes the magnetic force of the magnetic field and the direction switching of the centrifugal rotating mechanism to deflect the guide block in the chamber on the chip cover plate to the left and right, thereby realizing the switching of the liquid flow path in the chamber, and adopts the method of switching the flow path first and then flowing in the liquid sample, which can improve the accuracy of the liquid flow path switching. At the same time, the liquid flow path switching can be realized only by switching the direction and speed of the centrifugal rotating mechanism, which is low in cost, easy to use and highly practical.

[0005] In order to achieve the above objectives, the following technical solutions are adopted:

[0006] 20. The liquid flow path switching structure of claim 19, wherein the at least one liquid container is mounted on a surface of the at least one liquid container and wherein the container is mounted on a surface of the at least one liquid container and wherein the container is located adjacent to the container end of the at least one liquid container.

[0007] Furthermore, a first limiting groove connected to the sample injection port assembly is opened in the vertical direction on the top inner wall of the selection chamber; the flow channel switching assembly includes a connecting hose and a guide block arranged in the selection chamber and having magnetism; one end of the connecting hose is inserted into the first limiting groove, and the other end of the connecting hose is extended into the selection chamber; the top of the guide block is also provided with a first flow channel extending to the bottom thereof, and the end of the connecting hose extending into the selection chamber is inserted into the first flow channel from the top of the guide block.

[0008] Furthermore, the guide block is of cylindrical structure.

[0009] Furthermore, the sample injection port assembly includes a sample injection port opened on the chip cover, a buffer cavity communicated with the sample injection port, and a silicone membrane cavity communicated with the buffer cavity; the first limiting groove is communicated with the silicone membrane cavity.

[0010] Furthermore, a first capillary flow channel is provided on the bottom inner wall of the buffer cavity in a vertical direction, and the buffer cavity is communicated with the silicone membrane cavity via the first capillary flow channel.

[0011] Furthermore, the inner diameter of the first capillary channel is smaller than the inner diameter of the connecting hose.

[0012] Furthermore, the sample injection port assembly further comprises a lysis liquid chamber, a cleaning liquid chamber and an elution liquid chamber which are opened on the chip cover plate, and the lysis liquid chamber, the cleaning liquid chamber and the elution liquid chamber are all communicated with the buffer chamber.

[0013] Furthermore, an isolation protrusion is provided in the middle of the bottom inner wall of the selection cavity.

[0014] Furthermore, the liquid flow channel switching structure further includes a chip sealing plate arranged on one side of the chip cover plate.

[0015] By adopting the above scheme, the beneficial effects of the present invention are:

[0016] This structure uses the magnetic force of the magnetic field and the direction switching of the centrifugal rotating mechanism to deflect the guide block in the chamber on the chip cover plate to the left and right, thereby realizing the switching of the liquid flow path in the chamber. The method of switching the flow path first and then flowing in the liquid sample can improve the accuracy of the liquid flow path switching. At the same time, the liquid flow path switching can be achieved only by switching the direction and speed of the centrifugal rotating mechanism. It is low cost, easy to use and highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A perspective view of the present invention;

[0018] Figure 2 for Figure 1 Front view of (omitting the chip sealing plate);

[0019] Figure 3 is a cross-sectional view of a guide pad of the present invention;

[0020] Figure 4 This is a schematic structural diagram of the chip cover of the present invention when the guide block approaches the magnet during forward rotation;

[0021] Figure 5 This is a structural schematic diagram of the chip cover of the present invention when the guide block approaches the magnet during forward rotation;

[0022] Figure 6 This is a structural schematic diagram of the chip cover of the present invention, when the guide block approaches the magnet during forward rotation, driving the guide block to deflect;

[0023] Figure 7 This is a structural schematic diagram of the chip cover plate of the present invention, in which when the guide block is away from the magnet, it is thrown toward the second liquid chamber under the action of centrifugal force;

[0024] The accompanying drawings illustrate:

[0025] 1—Chip cover; 2—Magnet;

[0026] 3—injection port assembly; 4—selection cavity;

[0027] 5—first liquid chamber; 6—second liquid chamber;

[0028] 7—flow channel switching assembly; 8—chip sealing plate;

[0029] 9—first capillary flow channel; 10—isolation protrusion;

[0030] 31—sample port; 32—silicone membrane cavity;

[0031] 33—buffer chamber; 34—lysate chamber;

[0032] 35—cleaning fluid chamber; 36—elution fluid chamber;

[0033] 71—connecting hose; 72—guide block;

[0034] 73—First flow channel. DETAILED DESCRIPTION

[0035] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Reference Figures 1 to 7 As shown, the present invention provides a liquid flow path switching structure, comprising a chip cover plate 1, and a centrifugal rotation mechanism for driving the chip cover plate 1 to perform centrifugal rotation. The structure also includes a magnet 2, which is fixedly mounted on the outside and arranged near the centrifugal center of the chip cover plate 1 during centrifugal rotation. The chip cover plate 1 is further provided with an injection port assembly 3 and a selection chamber 4, and the selection chamber 4 is provided with a first liquid chamber 5 and a second liquid chamber 6 at the lower ends thereof, respectively, which are connected to the selection chamber 4. A flow path switching assembly 7 capable of centrifugal swinging movement is also movably arranged in the selection chamber 4, and the flow path switching assembly 7 is connected to the injection port assembly 3 and has magnetic properties. The distance between the flow path switching assembly 7 and the centrifugal center of the chip cover plate 1 during centrifugal rotation is less than the distance between the magnet 2 and the centrifugal center. The flow path switching assembly 7 is used to guide the liquid sample injected through the injection port assembly 3 to the second liquid chamber 6 and the first liquid chamber 5, respectively, when the chip cover plate 1 performs forward and reverse rotation.

[0037] The top inner wall of the selection chamber 4 is provided with a first limiting groove in the vertical direction which is in communication with the sample injection port assembly 3; the flow channel switching assembly 7 includes a connecting hose 71 and a guide block 72 which is arranged in the selection chamber 4 and has a magnetic property; one end of the connecting hose 71 is inserted into the first limiting groove, and the other end of the connecting hose 71 extends into the selection chamber 4; the top of the guide block 72 is also provided with a first flow channel 73 which passes through the bottom thereof, and the connecting hose 71 extends into the selection chamber 4. The end is inserted into the first flow channel 73 from the top of the guide block 72; the guide block 72 is cylindrical in structure; the injection port assembly 3 includes a sample injection port 31 opened on the chip cover plate 1, a buffer cavity 33 connected to the sample injection port 31, and a silicone membrane cavity 32 connected to the buffer cavity 33; the first limiting groove is connected to the silicone membrane cavity 32; the bottom inner wall of the buffer cavity 33 is also provided with a first capillary flow channel 9 along the vertical direction, and the buffer cavity 33 is connected to the silicone membrane cavity 32 through the first capillary flow channel 9.

[0038] The inner diameter of the first capillary flow channel 9 is smaller than the inner diameter of the connecting hose 71; the sample injection port assembly 3 also includes a lysis liquid chamber 34, a cleaning liquid chamber 35 and an elution liquid chamber 36 opened on the chip cover plate 1, and the lysis liquid chamber 34, the cleaning liquid chamber 35 and the elution liquid chamber 36 are all connected to the buffer chamber 33; an isolation protrusion block 10 is also provided in the middle of the bottom inner wall of the selection chamber 4; the liquid flow channel switching structure also includes a chip sealing plate 8 arranged on one side of the chip cover plate 1.

[0039] Working principle of the present invention:

[0040] Continue to refer to Figures 1 to 7 As shown, in this embodiment, the centrifugal rotating mechanism is a centrifugal motor, which uses the magnetic force of the magnetic field and the steering switch of the centrifugal motor to make the guide block 72 in the chamber on the chip cover plate 1 swing left and right, thereby realizing the accurate switching of the left and right channels of the liquid sample; in this embodiment, a selection chamber 4 is provided on the chip cover plate 1, and a silicone membrane chamber 32 is provided above the selection chamber 4. The silicone membrane chamber 32 has a first capillary flow channel 9 (capillary valve) connected to the buffer chamber 33 at the centrifugal center end close to the chip cover plate 1 when performing centrifugal rotation motion, and a connecting hose 71 is placed in the selection chamber 4, one end of the connecting hose 71 is connected to the outlet of the silicone membrane chamber 32, and the other end is connected to the outlet of the silicone membrane chamber 32 with good magnetic conductivity. The guide block 72 is connected (a first flow channel 73 is processed on the guide block 72 for assembly with the connecting hose 71 and outflow of the liquid sample); a magnet 2 is also fixedly installed on the outside, and the magnet 2 is located below the chip cover 1, and the center of the magnet 2 is closer to the centrifugal center than the guide block 72. In this way, when the chip cover 1 is rotated to the point where the selection cavity 4 is located above the magnet 2, under the action of the magnetic field of the magnet 2, the guide block 72 will be attracted to the end of the selection cavity 4 close to the centrifugal center. At this time, the chip cover 1 continues to rotate, and under the dominant action of the magnetic field force, the guide block 72 will deviate left and right. The direction of deviation is determined by the direction of the centrifugal motor under the chip cover 1 at this time. Figure 2 When the centrifugal motor rotates forward (along direction A), the guide block 72 deflects to the right, and when the centrifugal motor rotates reversely (along direction B), the guide block 72 deflects to the left.

[0041] Reference Figures 4 to 7 The chip cover 1 rotates one circle forward, and the guide block 72 deflects. Initially, the chip cover 1 rotates at a low speed, and the magnetic field force is greater than the centrifugal force. Therefore, the guide block 72 is in the process of approaching the magnet 2 (e.g. Figures 4 to 5 ), affected by the magnetic field force, the guide block 72 will deviate to the end close to the centrifugal center. After the guide block 72 approaches the magnet 2 (such as Figure 6 ), the magnetic field force will drive the guide block 72 to deflect, and after the guide block 72 is away from the magnet 2 (such as Figure 7), under the action of centrifugal force, it will be thrown to the second liquid chamber 6, and so on. Since the centrifugal speed was low before, the first capillary flow channel 9 connected to the buffer chamber 33 restricted the breakthrough of the liquid sample. Therefore, the previous process was only a flow channel selection process (the second liquid chamber 6 was selected for the forward rotation) and the liquid sample did not circulate. When the centrifugal speed of the chip cover 1 is increased to a certain value, the centrifugal force is much greater than the magnetic field force. Even when the selection cavity 4 reaches directly above the magnet 2, the guide block 72 will not be attracted to the end close to the centrifugal center by the magnetic field force. At this time, the guide block 72 has no deflection movement, and the liquid sample suddenly The liquid breaks through the first capillary channel 9, flows out from the first channel 73 inside the guide block 72 through the connecting hose 71, and then enters the selected first liquid chamber 5 or second liquid chamber 6 (the second liquid chamber 6 is selected in forward rotation, and the first liquid chamber 5 is selected in reverse rotation); in this embodiment, the guide block 72 includes but is not limited to a magnet block, an iron block, etc., and the magnet 2 includes but is not limited to a permanent magnet, etc.; the chip cover 1 can be made of but is not limited to glass, quartz and high molecular polymers, such as PC, PMMA, PET, PP, EVA, PA, PDMS, etc.; the connecting hose 71 can be made of but is not limited to thermoplastic elastic plastics, etc.

[0042] In an example of practical application, this structure is used to achieve the separation of lysate, cleaning solution and eluate after passing through the membrane in the HPV detection sample membrane extraction method; wherein, the outer diameter of the connecting hose 71 is 1mm and the inner diameter is 0.5mm; the inner diameter of the first capillary flow channel 9 is 0.2mm and the depth is 0.2mm; the diameter of the guide block 72 is 4mm and the thickness is 3mm, the inner diameter of the first flow channel 73 on the guide block 72 is 0.9mm, and the depth of the connecting hose 71 inserted into the guide block 72 is about 3mm; the diameter of the magnet 2 is 8mm and the thickness is 3mm, and the magnet 2 is closer to the centrifugal center than the center of the guide block 72; a silicone membrane is pre-installed in the silicone membrane cavity 32, and the chip cover plate 1 and the chip sealing plate 8 are bonded with pressure-sensitive adhesive. Use hydraulic equipment to maintain pressure at 5MPA for 10 minutes to ensure chip bonding strength and avoid leakage of the microfluidic chip; add 50ul of cervical brushing eluate (i.e., the sample for HPV detection) into the sample injection port 31, add 200ul of lysis solution into the lysis solution chamber 34, and rotate the microchip cover plate 1 at a forward speed of 300rpm for ten minutes. At this time, the cervical brushing eluate and lysis solution flow into the buffer chamber 33 under the action of centrifugation. At a low speed, the liquid in the buffer chamber 33 cannot pass through the first capillary channel 9 and stays in the buffer chamber 33 for sample lysis; adjust the speed of the centrifugal motor to 100rpm in the forward direction. At a low speed, the magnetic force is much greater than the centrifugal force, and the flow channel switching component 7 switches to the direction of the second liquid chamber 6 (such as Figure 6); then adjust the centrifugal motor speed to 2000 rpm in the forward direction. At high speed, the liquid in the buffer chamber 33 breaks through the first capillary flow channel 9 and enters the silicone membrane chamber 32, then enters the connecting hose 71, and enters the second liquid chamber 6. The second liquid chamber 6 stores waste liquid; add 400 ul of cleaning liquid to the cleaning liquid chamber 35, then adjust the centrifugal motor speed to 2000 rpm in the forward direction. The cleaning liquid passes through the buffer chamber 33, the silicone membrane chamber 32, the connecting hose 71, and then enters the second liquid chamber 6; in the elution liquid chamber 200ul of eluent is added to 36, and the speed of the centrifugal motor is adjusted to 100 rpm in reverse rotation. At this time, the liquid enters the buffer chamber 33 and stays there, and the flow channel switching component 7 switches to the direction of the first liquid chamber 5; then the speed of the centrifugal motor is adjusted to 2000 rpm in reverse rotation, and the liquid in the buffer chamber 33 passes through the silica gel membrane chamber 32, eluting the nucleic acid adsorbed on the silica gel membrane, and enters the connecting hose 71 together with the eluent, and finally enters the first liquid chamber 5. The liquid in the first liquid chamber 5 is the HPV detection sample extract.

[0043] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A liquid flow channel switching structure, comprising a chip cover plate and a centrifugal rotation mechanism for driving the chip cover plate to perform centrifugal rotation, characterized in that: The device further comprises a magnet, which is fixedly mounted on the outside and arranged near the centrifugal center of the chip cover when the chip cover performs centrifugal rotation; the chip cover is also provided with an injection port assembly and a selection chamber, and the lower ends of the selection chamber are respectively provided with a first liquid chamber and a second liquid chamber connected to the selection chamber; a flow channel switching assembly capable of centrifugal swinging movement is movably arranged in the selection chamber, and the flow channel switching assembly is connected to the injection port assembly and has magnetism; the distance between the flow channel switching assembly and the centrifugal center of the chip cover when the chip performs centrifugal rotation is less than the distance between the magnet and the centrifugal center; the flow channel switching assembly is used to guide the liquid sample injected through the injection port assembly to the second liquid chamber and the first liquid chamber respectively when the chip cover performs forward and reverse rotation; The top inner wall of the selection chamber is provided with a first limiting groove in a vertical direction, which is in communication with the sample injection port assembly. The flow channel switching assembly includes a connecting hose and a magnetic guide block arranged in the selection chamber. One end of the connecting hose is inserted into the first limiting groove, and the other end of the connecting hose extends into the selection chamber. The top of the guide block is also provided with a first flow channel extending from the bottom thereof. The end of the connecting hose extending into the selection chamber is inserted into the first flow channel from the top of the guide block. The liquid flow channel switching structure further includes a chip sealing plate arranged on one side of the chip cover plate.

2. The liquid flow channel switching structure according to claim 1, characterized in that: The guide block is in a cylindrical structure.

3. The liquid flow channel switching structure according to claim 1, characterized in that: The sample injection port assembly includes a sample injection port opened on the chip cover, a buffer cavity communicated with the sample injection port, and a silicone membrane cavity communicated with the buffer cavity; the first limiting groove is communicated with the silicone membrane cavity.

4. The liquid flow channel switching structure according to claim 3, characterized in that: A first capillary flow channel is further provided on the bottom inner wall of the buffer cavity along the vertical direction, and the buffer cavity is communicated with the silicone membrane cavity via the first capillary flow channel.

5. The liquid flow channel switching structure according to claim 4, characterized in that: The inner diameter of the first capillary flow channel is smaller than the inner diameter of the connecting hose.

6. The liquid flow channel switching structure according to claim 3, characterized in that: The sample injection port assembly further comprises a lysis liquid chamber, a cleaning liquid chamber and an elution liquid chamber which are opened on the chip cover plate, and the lysis liquid chamber, the cleaning liquid chamber and the elution liquid chamber are all communicated with the buffer chamber.

7. The liquid flow channel switching structure according to claim 1, characterized in that: An isolation protrusion is also provided in the middle of the bottom inner wall of the selection cavity.

Images