Liquid transfer device and liquid transfer method

Abstract

The present invention discloses a liquid transfer device and a liquid transfer method. The liquid transfer device includes a container, the container has a cavity; the cavity is divided into a first cavity and a second cavity adjacent to the first cavity by a sealing valve; the inner wall of the container is provided with a valve seat for limiting the lowest stroke position of the sealing valve; a power mechanism is provided inside the first cavity, and the power mechanism controls the longitudinal movement of the sealing valve relative to the power mechanism; the sealing valve or the inner wall of the cavity and the sealing valve have a flow channel connecting the first cavity and the second cavity when the sealing valve leaves the valve seat. The present invention solves the problems of precision control and wear of the piston mechanical structure in the prior art by changing the pressure difference, and completes micro-liquid extraction by moving the sealing valve through a small stroke.

Description

Technical Field

[0001] The invention relates to a liquid transfer device, and in particular to a liquid transfer device and a liquid transfer method. Background Art

[0002] At present, air displacement pipettes such as piston pipette structures need to precisely locate the position of the piston through mechanical structures to achieve the requirements of accurate pipetting. However, due to the inherent limitations of the mechanical structure, especially for small micro-pipettes, such as 1μL pipetting, according to the current existing pipette piston sleeve inner diameter within 5 mm and 5% accuracy, the positioning accuracy of the piston needs to be in the order of several microns, which puts forward extremely high requirements on the angular resolution of the micro-stepping or servo motor used in the pipette, the processing accuracy and backlash of the transmission mechanism such as gears or screws, and the clearance of various bearings.

[0003] In addition, accurate piston positioning also depends on good piston sealing to achieve accurate pipetting. In order to avoid contamination of reagents, the piston cannot be lubricated, and due to size limitations, the power of the motor is not very large, so the piston interference cannot be designed too large. However, the total life of the instrument requires that the piston can still be well sealed after running millions of times. These have high requirements on the material of the sealing ring and the roughness of the inner wall of the piston sleeve. Summary of the invention

[0004] Purpose of the invention: In order to overcome the defects of the prior art, the present invention provides a liquid transfer device, which overcomes the problems of high cost and difficult process of the mechanism using piston motion positioning in the prior art. The present invention also provides a method for liquid transfer using the liquid transfer device.

[0005] Technical solution: A liquid transfer device according to the present invention comprises a container, wherein the container has a cavity;

[0006] The cavity is divided into a first cavity and a second cavity adjacent to the first cavity by a sealing valve; the inner wall of the container is provided with a valve seat for limiting the lowest stroke position of the sealing valve;

[0007] A power mechanism is disposed inside the first cavity, and the power mechanism controls the sealing valve to move relative to the power mechanism;

[0008] A flow channel is provided on the sealing valve or between the inner wall of the cavity and the sealing valve, which communicates the first cavity with the second cavity when the sealing valve leaves the valve seat.

[0009] A preferred structure of the present invention is that the power mechanism is an electromagnetic spring, including an electromagnet mainly composed of an iron core and a coil; the end surface of the sealing valve opposite to the power mechanism is provided with a magnet structure. Preferably, the magnet structure is a permanent magnet.

[0010] The sealing valve includes a valve core fixed to the magnet structure.

[0011] The lower end surface of the valve core is convex and has a truncated cone structure.

[0012] The valve seat comprises a contact edge which forms a sealing surface with the lower end surface of the valve core.

[0013] The valve seat is a partition formed by the inner circumferential surface of the container protruding inwards; and / or the partition is a slope formed by the inner circumferential surface of the container protruding inwards.

[0014] The lower opening of the container is provided with an interface end for mounting a pipette tip; and / or the interface end is detachably mounted with a pipette tip.

[0015] The magnet structure of the sealing valve is embedded in the upper end of the valve core, and a gap for forming a flow channel is provided between the outer wall of the upper part of the sealing valve and the inner wall of the container.

[0016] The liquid transfer method of the above-mentioned liquid transfer device comprises the following steps:

[0017] (a) Before pipetting: the sealing valve is attached to the valve seat, dividing the cavity in the container into a first cavity and a second cavity, the first cavity is in a stable negative pressure state, and the second cavity is the external air pressure in the use state; the sealing valve described in the present invention is attached to the valve seat. In a preferred embodiment, the sealing valve is attached to the valve seat under the repulsive force of the power mechanism.

[0018] (b) During pipetting: When preparing to absorb the liquid, the lower end of the pipette tip installed below the pipetting device is brought into contact with the liquid surface, and the repulsive force of the power mechanism on the sealing valve is reduced, so that the sealing valve leaves the valve seat due to the change in force, connecting the first cavity and the second cavity, and the pressure in the second cavity is reduced. The external air pressure presses the liquid into the pipette tip to obtain the liquid;

[0019] (c) Liquid discharge.

[0020] Preferably, in step (b), the sealing valve moves upward and leaves the valve seat to connect the first cavity with the second cavity, the pressure in the second cavity decreases, and the atmospheric pressure presses the liquid into the pipette tip installed below the pipetting device to extract the liquid.

[0021] Preferably, the step (b) is as follows: during pipetting: when preparing to absorb the required amount of liquid, first make the lower end of the pipette tip installed below the pipetting device contact the liquid surface, and then reduce the repulsive force of the power mechanism on the sealing valve by controlling the current value of the coil on the power mechanism adapted to the said pipetting amount, so that the sealing valve moves upward due to the change in force and leaves the valve seat to connect the first cavity and the second cavity, the pressure in the second cavity is reduced, and the external air pressure presses the required amount of liquid into the pipette tip to take the liquid.

[0022] Preferably, the step (b) is as follows: during pipetting: when preparing to absorb the required amount of liquid, first make the lower end of the pipette tip installed below the pipetting device contact the liquid surface, and then reduce the repulsive force of the power mechanism on the sealing valve by controlling the current value of the coil on the power mechanism adapted to the said pipetting amount, so that the sealing valve moves upward along the longitudinal axis of the cavity due to the change in force, leaves the valve seat and connects the first cavity with the second cavity, the pressure in the second cavity is reduced, and the pipette tip installed below the pipetting device absorbs the required amount of liquid to obtain the liquid.

[0023] Beneficial effects: (1) The present invention overcomes the accuracy problem caused by relying on mechanical transmission (such as piston movement) in the prior art, and controls the movement of the sealing valve by controlling the change of the force on the sealing valve through the power mechanism, and realizes the transfer of liquid by changing the pressure in the upper and lower cavities of the sealing valve; (2) Based on the structure and construction provided by the present invention, the repulsive force of the power mechanism on the sealing valve adapted to the transfer amount can be accurately adjusted by controlling the current value of the coil on the power mechanism, thereby controlling the movement of the sealing valve by changing the force on the upper and lower surfaces of the sealing valve, and realizing the accurate transfer of the required transfer amount by changing the pressure in the upper and lower cavities; (3) The present invention further seals the side wall of the sealing valve with the valve seat, and compared with the traditional side wall seal, the movement stroke is small, and the wear of the sealing surface of the sealing valve is effectively reduced; (4) The present invention controls the two sides of the sealing valve through the power mechanism The force difference is used to control the movement of the sealing valve. Therefore, it is not necessary to precisely control the negative pressure in the first cavity and the pressure in the second cavity during the pipetting process. It is sufficient as long as the negative pressure in the first cavity is stable before the pipetting is prepared. Moreover, compared with the prior art, there is no need to use a pressure sensor in the second cavity and the pipette tip. The structure is simple and ingenious, and it saves cost. (5) The structure of the present invention overcomes the problem in the prior art that when a volatile liquid is transferred, the liquid may evaporate during the transfer process, causing the pressure above the liquid surface to increase and drip. When the pipetting device provided by the present invention is used for pipetting, the volatilization of the liquid will cause the pressure in the second cavity to rise, and then the sealing valve will automatically open to connect the upper and lower cavities, thereby reducing the pressure in the second cavity and effectively preventing dripping during the transfer process. There is no need to repeatedly move the piston to compensate for the increased pressure. The structure is reasonable and easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic cross-sectional view of the structure of Embodiment 1 of the present invention;

[0025] Figure 2 This is a schematic three-dimensional diagram of the structure of one of the sealing valves used in Example 1 of the present invention;

[0026] Figure 3 for Figure 2 A schematic cross-sectional view of a sealing valve when it is located in a container;

[0027] Figure 4A schematic cross-sectional view of the structure of another sealing valve used in Example 1 of the present invention;

[0028] Figure 5 This is a schematic three-dimensional diagram of the structure of another sealing valve used in Example 1 of the present invention;

[0029] Figure 6 for Figure 5 A schematic cross-sectional view of a sealing valve when located in a container. DETAILED DESCRIPTION

[0030] The structure of the present invention is further described below in conjunction with the accompanying drawings.

[0031] Example 1: Figure 1 As shown, a liquid transfer device of the present invention comprises a container 10 , wherein the container 10 has a cavity 100 . In this embodiment, the container 10 has a longitudinally extending cavity 100 , and the cavity has a longitudinal axis 11 .

[0032] The cavity 100 is divided into a first cavity 101 and a second cavity 102 located below the first cavity 101 by a sealing valve 20. When the pipetting device is installed with a pipette tip 60, the second cavity 102 includes the cavity surrounded by the pipette tip 60, that is, the second cavity 102 is connected with the cavity of the pipette tip 60 as a whole, which is collectively referred to as the second cavity 102 in the present embodiment. The second cavity 102 is connected to the outside when no pipetting is performed. For example, when the pipetting device of the present embodiment is used under standard atmospheric pressure, the pressure in the second cavity 102 when no pipetting is performed is the standard atmospheric pressure.

[0033] The first cavity 101 is provided with a power mechanism 30, which is used to control the longitudinal distance (the extension direction of the longitudinal axis 11) between the sealing valve 20 and the power mechanism 30, so that the sealing valve 20 leaves the valve seat 40 and connects the first cavity 101 and the second cavity 102. In other embodiments, the sealing valve 20 can move longitudinally relative to the power mechanism 30 along the longitudinal axis 11. In this embodiment, the power mechanism 30 is an electromagnetic spring, which mainly includes an iron core 301 and an electromagnet composed of a coil 302 surrounding the outer periphery of the iron core 301.

[0034] The inner wall of the container 10 is provided with a valve seat 40 for positioning and limiting the lowest position of the sealing valve 20. The valve seat 40 has a contact edge 401, which contacts the side wall of the sealing valve 20 and forms a dividing surface together with the sealing valve 20 to divide the cavity 100 into independent cavities (the first cavity 101 and the second cavity 102 in this embodiment).

[0035] The structure of the valve seat 40 forming the contact edge 401 can be various, such as a circular ring structure (ring surface) extending horizontally from the inner wall of the container 10, or a protruding structure extending from the inner wall of the container 10, and the shape of the protrusion is not limited. When the contact edge 401 is formed by the ring surface, the ring surface can be arranged perpendicularly or non-perpendicularly to the longitudinal axis 11, that is, the contact edge 401 only needs to clamp the sealing valve 20 and form a structure that separates the cavity 100 together with the sealing valve 20.

[0036] In order to realize the control of the sealing valve 20 by the power mechanism 30, the end face of the sealing valve 20 opposite to the power mechanism 30 is a magnet structure 201 (permanent magnet). When the coil 302 is energized, a repulsive force is generated on the magnet structure, and the sealing valve 20 is fixed on the valve seat 40 by the repulsive force. The sealing valve 20 is stuck on the contact edge 401 of the valve seat 40.

[0037] Another structure of the sealing valve 20 in the present embodiment is that the sealing valve 20 has a valve core 202 embedded with a magnet structure 201, and a cavity for accommodating the magnet structure 201 is provided above the valve core 202. The magnet structure 201 is fixed in the cavity so that the magnet structure 201 and the valve core 202 form an integrated structure. In order to further reduce the friction between the sealing valve 20 and the valve seat 40 without affecting the sealing performance, the structure of the lower end of the sealing valve 20 is preferably a truncated cone structure, and the truncated cone surface of the truncated cone structure forms a sealing surface with the contact edge 401 to separate the first cavity 101 and the second cavity 102.

[0038] In order to match the truncated cone structure at the lower end of the sealing valve 20, the valve seat 40 is provided with a partition 402 protruding inwardly from the inner circumferential surface of the container 10, that is, the sealing valve 20 is clamped on the partition 402. At the same time, a flow channel 103 is provided between the upper part of the sealing valve 20 and the inner wall of the container 10 for air circulation.

[0039] Furthermore, the valve seat 40 is a sloped surface formed by the inward protrusion of the inner circumferential surface of the container 10 (an inverted truncated cone structure matching the truncated cone structure at the lower end of the sealing valve 20). When this structure is adopted, the structure of the container 10 can be optimized at the same time, that is, the inner diameter of the second cavity 102 is smaller than the inner diameter of the first cavity 101, and a sloped surface is formed at the connection between the first cavity 101 and the second cavity 102. The sloped surface is the valve seat 40 structure described in this embodiment, and the truncated cone structure at the lower end of the sealing valve 20 is stuck on the sloped surface, that is, the inverted truncated cone structure matching the lower end of the sealing valve 20. When this structure is adopted, the contact surface between the sealing valve 20 and the valve seat 40 also forms a contact edge 401.

[0040] The structure of the sealing valve 20 is further optimized, that is, the sealing valve 20 is composed of a truncated cone structure and a cylindrical structure. The truncated cone structure is stuck on the slope, and the outer diameter of the cylindrical structure (located in the first cavity) is smaller than the inner diameter of the first cavity, and the gap between the cylindrical structure and the inner wall of the first cavity 101 forms a flow channel 103; the valve seat 40 adopts a slope structure and the truncated cone structure of the sealing valve 20 can further reduce wear and increase service life.

[0041] The flow channel 103 provided on the sealing valve 20 for connecting the first cavity 101 and the second cavity 102 when the sealing valve leaves the valve seat can also be realized by other methods. Figure 2 As shown, in some embodiments, the sealing valve 20 is composed of a truncated cone structure and a cylindrical structure located at the upper part. When the sealing valve 20 is attached to the valve seat 40, the bottom surface of the truncated cone structure is attached to the above-mentioned slope surface, and the cylindrical structure of the sealing valve is concave at the edge of the cylinder to form a plurality of circumferentially distributed flow channels 103, as shown in FIG. Figure 3 As shown, at this time, the horizontal cross-section of the cylindrical structure above the sealing valve 20 is a circular surface with a plurality of small notches evenly distributed around the outer edge. In this embodiment, the outer wall of the cylindrical structure is partially fitted with the inner wall of the first cavity. Due to the notch structure on the outer edge of the cross-section, there is a gap between the outer wall of the cylindrical structure and the inner wall of the first cavity of the container to form a flow channel 103. When the sealing valve leaves the valve seat, the first cavity 101 and the second cavity 102 can be connected through the flow channel 103.

[0042] like Figure 4 and Figure 5 As shown, in some embodiments, the sealing valve 20 is composed of a truncated cone structure and a cylindrical structure located at the upper part. When the sealing valve is attached to the valve seat, the bottom surface of the truncated cone structure is attached to the above-mentioned slope surface. On the cross section of the cylindrical structure of the sealing valve, a plurality of circular through holes are evenly distributed circumferentially on the circular surface away from the center and close to the outer edge, such as Figure 6 As shown, in this embodiment, the outer wall of the cylindrical structure can be completely fitted with the inner wall of the first cavity, and when the sealing valve is fitted with the valve seat, the first cavity 101 and the second cavity 102 are separated. When the sealing valve leaves the valve seat, a flow channel 103 can be formed by several circular through holes passing through the upper and lower parts of the cylindrical structure to connect the first cavity 101 and the second cavity 102.

[0043] Of course, the flow channel 103 can also be implemented in other ways, as long as it can be achieved that when the sealing valve is in contact with the valve seat, the first cavity 101 and the second cavity 102 are separated by the sealing valve, and when the sealing valve leaves the valve seat, the first cavity 101 and the second cavity 102 are connected through the flow channel 103.

[0044] The lower opening of the container 10 in this embodiment is provided with an interface end 50 for installing a pipette tip, and the interface end 50 is detachably mounted with a pipette tip 60. The connection method between the interface end 50 and the pipette tip 60 can adopt any structure in the prior art to meet the requirements of the detachable socket pipette tip 60.

[0045] The liquid transfer method of the liquid transfer device of the present invention is:

[0046] (a) Before pipetting: the sealing valve 20 is attached to the valve seat 40 under the repulsive force of the power mechanism, and the cavity in the container 10 is divided into a first cavity 101 and a second cavity 102. The first cavity 101 is in a stable negative pressure state, and the second cavity 102 is the external air pressure in the use state, which is the standard atmospheric pressure in this embodiment;

[0047] (b) During pipetting: When preparing to absorb liquid, the lower end of the pipette tip installed below the pipetting device is brought into contact with the liquid surface, and the repulsive force of the power mechanism 30 on the sealing valve 20 is reduced by controlling the current value of the coil on the power mechanism 30 adapted to the amount of liquid to be pipetted, so that the sealing valve 20 moves upward along the longitudinal axis 11 due to the change in force (pressure difference between the upper and lower cavities) to leave the valve seat 40 and connect the first cavity 101 with the second cavity 102, the pressure in the second cavity is reduced, and the atmospheric pressure presses the liquid into the pipette tip installed below the pipetting device to extract the liquid;

[0048] (c) Liquid discharge.

[0049] The working principle of the liquid transfer device of the present invention is:

[0050] The first cavity 101 is filled with a stable negative pressure. The iron core 301 and the coil 302 form an electromagnet as a power mechanism. When the power mechanism 30 is ready to transfer liquid, the power is turned on. The electromagnet presses the valve core 202 onto the valve seat 40 inside the container 10 through the repulsive force on the magnet structure 20, and forms a sealing surface together with the valve core 202 through the slope surface of the valve seat 40, thereby completely separating the first cavity 101 from the second cavity 102. When it is necessary to absorb a specified volume of liquid, the lower end of the pipette tip 60 is first brought into contact with the liquid surface, and then the repulsive force is reduced by controlling the current of the coil 302. The atmospheric pressure in the pipette tip 60 will push the valve core 202 upward along the longitudinal axis 11 for a small distance, so that the first cavity 101, the second cavity 102 and the inner cavity of the pipette tip of the container 10 are connected through the flow channel 103 around the valve core 202. The pressure in the pipette tip 60 is reduced, and the atmospheric pressure presses the liquid into the pipette tip 60. When the pressure difference between the cavity on the liquid column in the pipette tip (that is, the second cavity 102) and the first cavity 101 of the container 10 is reduced to the sum of the electromagnetic repulsive force and gravity on the magnet, the sealing valve 20 is closed under the action of the repulsive force of the magnet (when the pressure difference in the first cavity 101 and the second cavity 102 is balanced with the repulsive force of the power mechanism 30 and the gravity of the sealing valve 20, the sealing valve 20 returns to the valve seat 40, and the pressure in the first cavity 101 no longer decreases). The parameters that affect the current include the size of the valve core 202, the specifications of the iron core 301 and the coil 302 and the container 10, etc. These are all known parameters that can be obtained before pipetting. Therefore, by controlling the current of the coil 3, the pressure in the pipette tip 60 can be indirectly and accurately controlled. The difference between the pressure in the pipette tip 60 and the atmospheric pressure determines the height of the liquid column in the pipette tip 60, that is, the amount of pipetting (the amount of pipetting can also be called the amount of liquid taken).

[0051] The liquid discharge method of the liquid transfer device of the present invention can be realized by the existing technology, which will not be elaborated. For example, the pressure in the first cavity 101 can be increased (the pressure in the first cavity 101 is greater than the pressure in the second cavity 102 to prevent the liquid in the pipette tip 60 from flowing back), and then the current direction in the electromagnet coil 302 is changed. At this time, the repulsive force of the electromagnet on the upper end of the sealing valve 20 becomes an attractive force, and the sealing valve 20 leaves the valve seat 40 to connect the first cavity and the second cavity. The pressure of the first cavity 101 discharges the liquid in the pipette tip 60 to achieve liquid discharge. Alternatively, a bypass (not shown in the figure) connected to the second cavity 102 is provided on the side wall of the interface end 50. When taking liquid, the bypass is closed. When discharging liquid, the bypass is opened, and gas is sent from the bypass into the second cavity 102 to discharge the liquid in the pipette tip 60. In addition to the above-mentioned methods, the liquid transfer device of the present invention can also use other technologies in the prior art to achieve liquid discharge.

[0052] It can be seen from the structure of the present invention that the present invention controls the opening and closing of the sealing valve 20 through the electromagnetic structure, without the trouble of mechanical positioning. In addition, since the movement stroke of the sealing valve 20 in the open and closed state is very small, and the sealing of the non-vertical surface (such as the inverted frustum-shaped sealing contact surface) can be achieved through the sealing valve 20 and the valve seat slope, the side wall of the sealing valve 20 in contact with the container 10 is also preferably matched with a gap, thereby greatly reducing the operating wear of the sealing valve and being durable. The valve seat of the present invention adopts a slope structure, which can achieve bevel-bevel sealing through the effect of gravity compaction, without the need for interference fit, and further solves the wear problem caused by the need for interference fit when sealing the vertical side in the prior art.

[0053] In addition, since the present invention controls the opening and closing of the sealing valve 20 by adjusting the repulsive force of the magnet, that is, adjusting the force difference at both ends of the valve seat 40, it is not necessary to accurately control the negative pressure in the first cavity and the pressure in the second cavity during the transfer process. As long as the negative pressure in the first cavity is stable before the transfer is prepared, relative to the prior art, there is no need to use a pressure sensor in the second cavity and the pipette tip, and the structure is more reasonable, concise and ingenious. If the absorbed liquid is volatile, causing the pressure in the pipette tip 60 above the liquid surface to rise, the sealing valve 20 will automatically open to connect the upper and lower cavities to reduce the pressure in the pipette tip above the liquid surface, thereby preventing dripping during the transfer process, effectively avoiding the problem of the prior art that the piston needs to be repeatedly moved to compensate for the increased pressure, and has good ease of use.

Claims

1. A liquid transfer device, characterized in that: It comprises a container (10), wherein the container (10) has a cavity (100); The cavity (100) is divided into a first cavity (101) and a second cavity (102) adjacent to the first cavity (101) by a sealing valve (20); the inner wall of the container (10) is provided with a valve seat (40) for limiting the lowest stroke position of the sealing valve (20); A power mechanism (30) is arranged inside the first cavity (101); the power mechanism (30) is an electromagnetic spring, comprising an electromagnet composed of an iron core (301) and a coil (302); the power mechanism (30) controls the sealing valve (20) to move relative to the power mechanism (30); a magnet structure (201) is arranged on the end surface of the sealing valve (20) opposite to the power mechanism (30); the sealing valve (20) further comprises a valve core (202) fixed to the magnet structure (201); when the coil (302) is energized, a repulsive force is generated on the magnet structure (201); the sealing valve (20) is fixed to the valve seat (40) by the repulsive force, and the sealing valve (20) is clamped on the contact edge (401) of the valve seat (40); The valve seat (40) is a partition formed by the inner circumferential surface of the container protruding inwards; the partition is a slope formed by the inner circumferential surface of the container protruding inwards; The structure of the lower end of the sealing valve (20) is a truncated cone-shaped structure, and the truncated cone surface of the truncated cone-shaped structure and the contact edge (401) form a sealing surface to separate the first cavity (101) and the second cavity (102); A flow channel (103) is provided on the sealing valve (20) or between the inner wall of the cavity (100) and the sealing valve (20), which connects the first cavity (101) and the second cavity (102) when the sealing valve (20) leaves the valve seat (40).

2. The liquid transfer device according to claim 1, characterized in that: A gap capable of forming a flow channel (103) is provided between the outer wall of the upper portion of the sealing valve (20) and the inner wall of the container (10).

3. The liquid transfer device according to claim 1, characterized in that: The sealing valve (20) is composed of a truncated cone structure and a cylindrical structure located at the top, and the cylindrical structure is located in the first cavity (101).

4. The liquid transfer device according to claim 1, characterized in that: The cylindrical structure of the sealing valve (20) is concave at the edge of the cylinder to form a plurality of circumferentially distributed flow channels (103).

5. The liquid transfer device according to claim 1, characterized in that: The outer wall of the cylindrical structure of the sealing valve (20) is completely fitted with the inner wall of the first cavity (101); a plurality of circular through holes are evenly distributed circumferentially on a circular surface of the cylindrical structure portion of the sealing valve (20) away from the center of the circle and close to the outer edge of the cylindrical structure; the plurality of circular through holes penetrate the cylindrical structure to form a flow channel (103); the flow channel (103) connects the first cavity (101) and the second cavity (102).

6. The liquid transfer device according to claim 3, characterized in that: The outer diameter of the cylindrical structure located in the first cavity (101) is smaller than the inner diameter of the first cavity (101), and the gap between the cylindrical structure and the inner wall of the first cavity (101) forms the flow channel (103).

7. The liquid transfer device according to claim 1, characterized in that: The lower opening of the container (10) is provided with an interface end (50) for mounting a pipette tip.

8. The liquid transfer device according to claim 7, characterized in that: The interface end (50) is detachably mounted with a pipette tip (60).

9. The liquid transfer method of the liquid transfer device according to claim 1, characterized in that: The following steps are involved: (a) Before liquid transfer: the sealing valve (20) is attached to the valve seat (40), dividing the cavity (100) in the container (10) into a first cavity (101) and a second cavity (102), wherein the first cavity (101) is in a stable negative pressure state, and the second cavity (102) is in an external air pressure state in a use state; (b) During pipetting: When preparing to absorb the liquid, the lower end of the pipette tip installed below the pipetting device is brought into contact with the liquid surface, and the repulsive force of the power mechanism (30) on the sealing valve (20) is reduced, so that the sealing valve (20) leaves the valve seat (40) due to the change in force, thereby connecting the first cavity (101) and the second cavity (102), and the pressure in the second cavity (102) is reduced. The external air pressure presses the liquid into the pipette tip, and the liquid is extracted; (c) Liquid discharge.

10. The liquid transfer method of the liquid transfer device according to claim 9, characterized in that: The step (b) is as follows: during liquid transfer: when preparing to absorb the required amount of liquid, firstly make the lower end of the pipette tip installed below the pipetting device contact the liquid surface, and then reduce the repulsive force of the power mechanism (30) on the sealing valve (20) by controlling the current value of the coil on the power mechanism (30) adapted to the amount of liquid transfer, so that the sealing valve (20) moves upward due to the change in force and leaves the valve seat (40) to connect the first cavity (101) and the second cavity (102), the pressure in the second cavity (102) is reduced, and the external air pressure presses the required amount of liquid into the pipette tip to obtain the liquid.

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