Micro-fluidic chip with phase change valve and use method of micro-fluidic chip

Abstract

The invention provides a micro-fluidic chip with a phase change valve and a use method of the micro-fluidic chip. The chip comprises a first cavity, a valve cavity and a second cavity, and the first cavity and the second cavity are separated through the valve cavity; a phase change valve is arranged in the valve cavity; the phase change valve comprises a micro valve and a hydrophobic isolator, a channel and a control part are arranged on the micro valve, the control part is used for controlling the micro valve to drive the channel to rotate, and the channel can communicate with the first cavity and the second cavity; the valve cavity is filled with an isolator, and the isolator can be switched between a liquid phase and a solid phase; when the isolator is in a liquid phase, the micro valve can be switched between an opening position and a closing position when rotating; when the micro valve is in the opening position, the first cavity and the second cavity can be communicated through the channel. When the micro valve is located at the closing position, the micro valve can isolate the first cavity from the second cavity. The micro-fluidic chip does not need to be stored at low temperature, the universality is improved, and double conditions are needed when the valve is opened to reduce misoperation.

Description

Technical Field

[0001] The present invention relates to the field of microfluidic technology, and in particular to a microfluidic chip with a phase change valve and a use method thereof. Background Art

[0002] Microfluidic chips integrate sample preparation, reaction, detection and other operational units in chemical, biological, medical and other analytical processes onto a micron-scale carrier to automatically complete the entire analysis process.

[0003] Among the current microfluidic chips, a large part of them use paraffin as phase change valves, and control the opening and closing of channels by melting and solidifying the paraffin. Paraffin valves have strict requirements on ambient temperature. Paraffin has a low melting point. Microfluidic chips with paraffin temperature control valves must be stored at low temperatures, making them difficult to preserve for a long time. In addition, during the production process, the entire platform needs to be heated and injected when the paraffin temperature control valve is filled into the chip. After filling the paraffin and then sealing, the paraffin will be squeezed, deformed, cracked, or fail, which makes production inconvenient. In addition, a large part of microfluidic chips use mechanical valves. If they want to maintain a high seal, they require a very high level of design, assembly process, and production cost, and have high requirements for supporting equipment. Summary of the invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the first purpose of the present invention is to provide a microfluidic chip with a phase change valve which has good sealing performance, is easy to operate, and is not prone to leakage.

[0005] The second objective of the present invention is to provide a method for using the above-mentioned microfluidic chip.

[0006] In order to achieve the above-mentioned first purpose, the microfluidic chip with a phase change valve provided by the present invention includes a first cavity, a valve cavity, and a second cavity, and the first cavity and the second cavity are separated by the valve cavity; a phase change valve is arranged in the valve cavity; the phase change valve includes a microvalve and a hydrophobic insulator, and a channel and a control part are arranged on the microvalve, and the control part is used to control the microvalve to drive the channel to rotate, and the channel can connect the first cavity and the second cavity; the valve cavity is filled with an insulator, and the insulator can switch between liquid phase and solid phase; when the insulator is in liquid phase, the microvalve can switch between an open position and a closed position when it rotates; when the microvalve is in the open position, the channel can connect the first cavity and the second cavity; when the microvalve is in the closed position, the microvalve can isolate the first cavity and the second cavity.

[0007] As can be seen from the above, since the micro-valve rotates within the valve cavity, there is a gap between the micro-valve and the valve cavity. By filling the gap with an isolating material, the sealing performance can be improved and leakage can be prevented. The combination of the isolating material and the micro-valve does not require low-temperature storage, which can improve the storage environment and enhance versatility. Additionally, compared with using a mechanical valve alone, when using a mechanical valve alone, misoperation may cause the mechanical valve to open, and at this time, there is a risk of mutual contamination of the reagents in the first cavity and the second cavity, resulting in the scrapping of the chip. However, in this solution, by adding a valve-opening interlock, misoperation can be avoided.

[0008] A further solution is that a track is provided on the cavity wall of the valve cavity; the track enables the micro-valve to move along the extension direction of the track. When the control part moves to the second end of the track, the micro-valve is in the open position, and the channel connects the first cavity and the second cavity; when the control part moves to the first end of the track, the micro-valve is in the closed position, and the micro-valve isolates the first cavity and the second cavity.

[0009] A further solution is that the control part can be adsorbed by a magnet. The control part is arranged in the valve cavity, and the cooperation between the control part and the track enables the micro-valve to move along the extension direction of the track.

[0010] As can be seen from the above, the control part being located in the valve cavity can effectively reduce the risk of leakage.

[0011] A further solution is that the phase-change valve further includes a first positioning pin and a second positioning pin; on the top wall of the valve cavity, a first limiting hole and a second limiting hole communicating with the valve cavity are provided. The first limiting hole and the second limiting hole are arranged along the circumferential direction of the micro-valve, and the channel is opposite to the bottom wall of the valve cavity; the first positioning pin is arranged in the first limiting hole, and the second positioning pin is arranged in the second limiting hole; on one side of the micro-valve close to the first limiting hole, a third limiting hole is provided. The extension directions of the third limiting hole, the second limiting hole, and the first limiting hole are the same, and the distance from the third limiting hole to the axis of the micro-valve is equal to the distance from the first limiting hole to the axis of the micro-valve; when the control part moves to the first end of the track, the first limiting hole communicates with the third limiting hole, and the first positioning pin can extend into the third limiting hole, and the micro-valve isolates the first cavity and the second cavity; when the control part moves to the second end of the track, the second limiting hole communicates with the third limiting hole, and the second positioning pin can extend into the third limiting hole, and both ends of the channel communicate with the first cavity and the second cavity respectively; the first positioning pin can pass through the first limiting hole and the third limiting hole at the same time, and the length of the first positioning pin is less than or equal to the length of the first limiting hole; the second positioning pin can pass through the second limiting hole and the third limiting hole at the same time, and the length of the second positioning pin is less than or equal to the length of the second limiting hole.

[0012] As can be seen from the above, the micro-valve is limited and fixed by the first positioning pin and the second positioning pin to prevent the micro-valve from continuing to move, and the structure is stable.

[0013] A further solution is that the phase change valve further includes a first positioning pin and a second positioning pin; a first limiting hole and a second limiting hole communicating with the valve cavity are formed in the top wall of the valve cavity, and the channel is opposite to the bottom wall of the valve cavity; the first positioning pin is arranged in the first limiting hole, and the second positioning pin is arranged in the second limiting hole; a third limiting hole and a fourth limiting hole are arranged on one side of the micro-valve close to the first limiting hole, the extending directions of the first limiting hole and the third limiting hole are the same, and the extending directions of the second limiting hole and the fourth limiting hole are the same; when the control part moves to the first end of the track, the first limiting hole communicates with the third limiting hole, and the first positioning pin can extend into the third limiting hole, and the micro-valve isolates the first cavity and the second cavity; when the control part moves to the second end of the track, the second limiting hole communicates with the fourth limiting hole, and the second positioning pin can extend into the fourth limiting hole, and both ends of the channel communicate with the first cavity and the second cavity respectively; the first positioning pin can be simultaneously inserted through the first limiting hole and the third limiting hole, and the length of the first positioning pin is less than or equal to the length of the first limiting hole; the second positioning pin can be simultaneously inserted through the second limiting hole and the fourth limiting hole, and the length of the second positioning pin is less than or equal to the length of the second limiting hole.

[0014] A further solution is that both the first positioning pin and the second positioning pin are located in the valve cavity; both the first positioning pin and the second positioning pin can be adsorbed by a magnet.

[0015] As can be seen from the above, both the first positioning pin and the second positioning pin are located in the valve cavity, which can improve the sealing performance of the chip and reduce the risk of leakage.

[0016] A further solution is that the isolating substance includes paraffin.

[0017] A further solution is that the micro-valve is made of plastic, and a receiving groove for receiving the control part is arranged on the micro-valve.

[0018] To achieve the above second object, the present invention also provides a method for using the above microfluidic chip, and the method includes:

[0019] When opening the micro-valve, heat the isolating substance into a liquid phase, and rotate the micro-valve so that the micro-valve is in the open position;

[0020] When closing the micro-valve, heat the isolating substance into a liquid phase, rotate the micro-valve so that the micro-valve is in the closed position, and wait for the isolating substance to cool and solidify into a solid state.

[0021] A further solution is that the phase change valve further includes a first positioning pin and a second positioning pin; on the cavity wall of the valve cavity, a first limiting hole and a second limiting hole communicating with the valve cavity are provided. The first limiting hole and the second limiting hole are arranged along the circumferential direction of the micro-valve, and the channel is opposite to the bottom wall of the valve cavity; the first positioning pin is arranged in the first limiting hole, and the second positioning pin is arranged in the second limiting hole; on one side of the micro-valve close to the first limiting hole, a third limiting hole is provided. The extending directions of the third limiting hole, the second limiting hole, and the first limiting hole are the same, and the distance from the third limiting hole to the axis of the micro-valve is equal to the distance from the first limiting hole to the axis of the micro-valve; when the control part moves to the first end of the track, the first limiting hole communicates with the third limiting hole, and the first positioning pin can extend into the third limiting hole, and the micro-valve isolates the first cavity and the second cavity; when the control part moves to the second end of the track, the second limiting hole communicates with the third limiting hole, and the second positioning pin can extend into the third limiting hole, and both ends of the channel communicate with the first cavity and the second cavity respectively; the first positioning pin can be simultaneously inserted through the first limiting hole and the third limiting hole, and the length of the first positioning pin is less than or equal to the length of the first limiting hole; the second positioning pin can be simultaneously inserted through the second limiting hole and the third limiting hole, and the length of the second positioning pin is less than or equal to the length of the second limiting hole; the control part, the first positioning pin, and the second positioning pin can all be adsorbed by a magnet;

[0022] The method further includes:

[0023] When opening the micro-valve, heat the isolating substance into a liquid phase, bring an external magnetic rod device close to the first limiting hole and the second limiting hole, suck the first positioning pin into the first limiting hole, the magnetic rod device controls the control part to move to the second end of the track, the second limiting hole communicates with the third limiting hole, the magnetic rod device leaves the microfluidic chip or loses magnetic force after power-off, and the second positioning pin extends into the third limiting hole under the action of gravity;

[0024] When closing the micro-valve, heat the isolating substance into a liquid phase, bring an external magnetic rod device close to the first limiting hole and the second limiting hole, suck the second positioning pin into the second limiting hole, the magnetic rod device controls the control part to move to the first end of the track, the first limiting hole communicates with the third limiting hole, the magnetic rod device leaves the microfluidic chip or loses magnetic force after power-off, and the first positioning pin extends into the third limiting hole under the action of gravity.

[0025] In summary, the microfluidic chip with a phase change valve of the present invention has good sealing performance, is convenient to operate, and is not prone to leakage. Description of the Drawings

[0026] Figure 1 It is an exploded view of an embodiment of the microfluidic chip with a phase change valve of the present invention.

[0027] Figure 2 It is an internal structure diagram of the upper cover plate of an embodiment of the microfluidic chip with a phase change valve of the present invention.

[0028] Figure 3 This is a state diagram of the upper cover plate and the microvalve when the microvalve of the microfluidic chip with a phase change valve according to the embodiment of the present invention is in the open position.

[0029] Figure 4 This is a state diagram of the upper cover plate and the microvalve when the microvalve of the microfluidic chip with a phase change valve according to the embodiment of the present invention is in the closed position.

[0030] Figure 5 This is a cross-sectional view of the upper cover plate and the microvalve of the microfluidic chip with a phase change valve according to the embodiment of the present invention. Detailed implementation mode

[0031] The microfluidic chip with a phase change valve provided in this embodiment includes an upper cover plate 16 and a lower cover plate 17. The upper cover plate 16 and the lower cover plate 17 enclose a first cavity 1, a valve cavity 2, and a second cavity 3. The first cavity 1 and the second cavity 3 are separated by the valve cavity 2. A phase change valve 4 is provided in the valve cavity 2. The phase change valve 4 includes a microvalve 5, a first positioning pin 14, a second positioning pin 15, and a hydrophobic isolator 6. In this embodiment, the isolator 6 is paraffin. Optionally, the isolator 6 can be switched between a solid phase and a liquid phase. The microvalve 5 is made of plastic.

[0032] A track 7, a first limiting hole 8, and a second limiting hole 9 are provided on the top wall of the valve cavity 2. The first limiting hole 8 and the second limiting hole 9 are arranged along the circumferential direction of the microvalve 5, and the track 7 extends along the circumferential direction of the valve cavity 2. The length of the first positioning pin 14 is greater than or equal to the length of the first limiting hole 8, and the length of the second positioning pin 15 is greater than or equal to the length of the second limiting hole 9.

[0033] A channel 10, a receiving groove 11, and a third limiting hole 12 are provided on the microvalve 5. The channel 10 faces the bottom wall of the valve cavity 2, and the third limiting hole 12 faces the top wall of the valve cavity 2. The receiving groove 11 is a through groove that penetrates the microvalve 5 in the direction from the bottom wall to the top wall of the valve cavity 2. A control part 13 is provided in the receiving groove 11. The control part 13 is spherical, the control part 13 is made of metal and can be adsorbed by a magnet, and the control part 13 can only move along the track 7. The first positioning pin 14 is arranged in the first limiting hole 8, the second positioning pin 15 is arranged in the second limiting hole 9, the lengths of the first positioning pin 14 and the second positioning pin 15 are both greater than the length of the third limiting hole 12. The first positioning pin 14 can extend into both the first limiting hole 8 and the third limiting hole 12 at the same time, and the second positioning pin 15 can extend into both the second limiting hole 8 and the third limiting hole 12 at the same time. The length of the first positioning pin 14 is less than or equal to the length of the first limiting hole 8, and the length of the second positioning pin 14 is less than or equal to the length of the second limiting hole 9. Both the first positioning pin 14 and the second positioning pin 15 can be adsorbed by a magnet.

[0034] When the isolator is in a liquid phase, when the control part 13 drives the micro-valve 5 to rotate and move to the first end of the track 7, the micro-valve 5 is in a closed position, the first limiting hole 8 communicates with the third limiting hole 12, and the first positioning pin 14 can extend into the third limiting hole 12, and the micro-valve 5 isolates the first cavity 1 and the second cavity 3.

[0035] When the control part 13 drives the micro-valve 5 to rotate and move to the second end of the track 7, the micro-valve 5 is in an open position, the second limiting hole 9 communicates with the third limiting hole 12, and the second positioning pin 15 can extend into the third limiting hole 12, and both ends of the channel 10 communicate with the first cavity 1 and the second cavity 3 respectively.

[0036] This embodiment also provides a method for using the above-mentioned microfluidic chip, and the method includes:

[0037] When it is necessary to open the micro-valve 5, the isolator 6 is heated into a liquid phase by using the heating wire on the microfluidic chip or an external heating device, the external magnetic bar device approaches the first limiting hole 8 and the second limiting hole 9, sucks the first positioning pin 14 into the first limiting hole 8, the magnetic bar device controls the control part 13 to move to the second end of the track 7, the magnetic bar device leaves the microfluidic chip or loses magnetic force after power-off, and the second positioning pin 15 extends into the third limiting hole 12 under the action of gravity, and the reagent extraction operation can be carried out;

[0038] When it is necessary to close the micro-valve 5, the isolator 6 is heated into a liquid phase, the external magnetic bar device approaches the first limiting hole 8 and the second limiting hole 9, sucks the second positioning pin 15 into the second limiting hole 9, the magnetic bar device controls the control part 13 to move to the first end of the track 7, the magnetic bar device leaves the microfluidic chip or loses magnetic force after power-off, and the first positioning pin 14 extends into the third limiting hole 12 under the action of gravity. After cooling, it can be stored and packed in a box.

[0039] Optionally, the phase change valve 4 further includes a first positioning pin 14 and a second positioning pin 15. The top wall of the valve cavity 2 is provided with a first limiting hole 8 and a second limiting hole 9 that communicate with the valve cavity 2. The channel 10 is opposite to the bottom wall of the valve cavity 2. The first positioning pin 14 is arranged in the first limiting hole 8, and the second positioning pin 15 is arranged in the second limiting hole 9. On one side of the micro-valve 5 close to the first limiting hole 8, a third limiting hole 12 and a fourth limiting hole (not shown in the figure) are provided. The extending directions of the first limiting hole 8 and the third limiting hole 12 are the same, and the extending directions of the second limiting hole 9 and the fourth limiting hole are the same. When the control part 13 moves to the first end of the track 7, the first limiting hole 8 communicates with the third limiting hole 12, and the first positioning pin 14 can extend into the third limiting hole 12, and the micro-valve 5 isolates the first cavity 1 and the second cavity 3. When the control part 13 moves to the second end of the track 7, the second limiting hole 9 communicates with the fourth limiting hole, and the second positioning pin 15 can extend into the fourth limiting hole. Both ends of the channel 10 communicate with the first cavity 1 and the second cavity 3 respectively. The length of the first positioning pin 14 is greater than the length of the third limiting hole 12, and the length of the first positioning pin 14 is less than or equal to the length of the first limiting hole 8. The length of the second positioning pin 15 is greater than the length of the fourth limiting hole, and the length of the second positioning pin 15 is less than or equal to the length of the second limiting hole 9. The first positioning pin 14 can be simultaneously inserted through the first limiting hole 8 and the third limiting hole 12, and the second positioning pin 15 can be simultaneously inserted through the second limiting hole 9 and the fourth limiting hole.

[0040] In summary, the microfluidic chip with a phase change valve in this embodiment has good sealing performance, is easy to operate, and is not prone to leakage.

[0041] Finally, it should be emphasized that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A microfluidic chip with a phase change valve, comprising a first cavity, a valve cavity, and a second cavity, wherein the first cavity and the second cavity are separated by the valve cavity; A phase change valve is disposed in the valve cavity; It is characterized in that: The phase change valve includes a micro valve and a hydrophobic isolator. A channel and a control part are provided on the micro valve. The control part is used to control the micro valve to drive the channel to rotate, and the channel can communicate the first cavity and the second cavity; The valve cavity is filled with the isolator, and the isolator can switch between a liquid phase and a solid phase; When the isolator is in the liquid phase, the micro valve can switch between an open position and a closed position when rotating; When the micro valve is in the open position, the channel can communicate the first cavity and the second cavity; When the micro valve is in the closed position, the micro valve can isolate the first cavity and the second cavity.

2. The microfluidic chip with a phase change valve according to claim 1, wherein: A track is provided on the cavity wall of the valve cavity; The track enables the micro valve to move along the extension direction of the track. When the control part moves to the second end of the track, the micro valve is in the open position, and the channel communicates the first cavity with the second cavity; When the control part moves to the first end of the track, the micro valve is in the closed position, and the micro valve isolates the first cavity from the second cavity.

3. The microfluidic chip with a phase change valve according to claim 2, wherein: The control part can be adsorbed by a magnet. The control part is disposed in the valve cavity, and the control part cooperates with the track to enable the micro valve to move along the extension direction of the track.

4. The microfluidic chip with a phase change valve according to claim 2, wherein: The phase change valve further includes a first positioning pin and a second positioning pin; A first limiting hole and a second limiting hole communicating with the valve cavity are formed on the top wall of the valve cavity. The first limiting hole and the second limiting hole are arranged along the circumferential direction of the micro valve, and the channel faces the bottom wall of the valve cavity; The first positioning pin is disposed in the first limiting hole, and the second positioning pin is disposed in the second limiting hole; A third limiting hole is provided on one side of the micro valve close to the first limiting hole. The extension directions of the third limiting hole, the second limiting hole, and the first limiting hole are the same, and the distance from the third limiting hole to the axis of the micro valve is equal to the distance from the first limiting hole to the axis of the micro valve; When the control part moves to the first end of the track, the first limiting hole communicates with the third limiting hole, and the first positioning pin can extend into the third limiting hole, and the micro valve isolates the first cavity and the second cavity; When the control part moves to the second end of the track, the second limiting hole communicates with the third limiting hole, and the second positioning pin can extend into the third limiting hole, and both ends of the channel communicate with the first cavity and the second cavity respectively; The first positioning pin can be simultaneously inserted into the first limiting hole and the third limiting hole, and the length of the first positioning pin is less than or equal to the length of the first limiting hole; The second positioning pin can be inserted into the second limiting hole and the third limiting hole simultaneously, and the length of the second positioning pin is less than or equal to the length of the second limiting hole.

5. The microfluidic chip with a phase change valve according to claim 2, characterized in that: The phase change valve further includes a first positioning pin and a second positioning pin; A first limiting hole and a second limiting hole communicating with the valve cavity are formed on the top wall of the valve cavity, and the channel is opposite to the bottom wall of the valve cavity; The first positioning pin is arranged in the first limiting hole, and the second positioning pin is arranged in the second limiting hole; On one side of the micro-valve close to the first limiting hole, a third limiting hole and a fourth limiting hole are provided. The extending directions of the first limiting hole and the third limiting hole are the same, and the extending directions of the second limiting hole and the fourth limiting hole are the same; When the control part moves to the first end of the track, the first limiting hole communicates with the third limiting hole, the first positioning pin can extend into the third limiting hole, and the micro-valve isolates the first cavity and the second cavity; When the control part moves to the second end of the track, the second limiting hole communicates with the fourth limiting hole, the second positioning pin can extend into the fourth limiting hole, and both ends of the channel communicate with the first cavity and the second cavity respectively; The first positioning pin can be inserted into the first limiting hole and the third limiting hole simultaneously, and the length of the first positioning pin is less than or equal to the length of the first limiting hole; The second positioning pin can be inserted into the second limiting hole and the fourth limiting hole simultaneously, and the length of the second positioning pin is less than or equal to the length of the second limiting hole.

6. The microfluidic chip with a phase change valve according to claim 4 or 5, characterized in that: Both the first positioning pin and the second positioning pin are located in the valve cavity; Both the first positioning pin and the second positioning pin can be adsorbed by a magnet.

7. The microfluidic chip with a phase change valve according to any one of claims 1 to 5, characterized in that: The isolating substance includes paraffin.

8. The microfluidic chip with a phase change valve according to any one of claims 1 to 5, characterized in that: The micro-valve is made of plastic, and a receiving groove for receiving the control part is provided on the micro-valve.

9. The method for using a microfluidic chip according to any one of claims 1 to 3, characterized in that: When opening the micro-valve, heat the isolating substance into a liquid phase, and rotate the micro-valve so that the micro-valve is in the open position; When closing the micro-valve, heat the isolating substance into a liquid phase, rotate the micro-valve so that the micro-valve is in the closed position, and wait for the isolating substance to cool and solidify into a solid state.

10. The method for use according to claim 9, characterized in that: The phase change valve further includes a first positioning pin and a second positioning pin; A first limiting hole and a second limiting hole communicating with the valve cavity are formed on the cavity wall of the valve cavity. The first limiting hole and the second limiting hole are arranged along the circumferential direction of the micro-valve, and the channel is opposite to the bottom wall of the valve cavity; The first positioning pin is arranged in the first limiting hole, and the second positioning pin is arranged in the second limiting hole; A third limiting hole is arranged on one side of the micro-valve close to the first limiting hole. The extending directions of the third limiting hole, the second limiting hole, and the first limiting hole are the same, and the distance from the third limiting hole to the axis of the micro-valve is equal to the distance from the first limiting hole to the axis of the micro-valve; When the control part moves to the first end of the track, the first limiting hole is communicated with the third limiting hole, the first positioning pin can extend into the third limiting hole, and the micro-valve isolates the first cavity and the second cavity; When the control part moves to the second end of the track, the second limiting hole is communicated with the third limiting hole, the second positioning pin can extend into the third limiting hole, and both ends of the channel are communicated with the first cavity and the second cavity respectively; The first positioning pin can pass through the first limiting hole and the third limiting hole at the same time, and the length of the first positioning pin is less than or equal to the length of the first limiting hole; The second positioning pin can pass through the second limiting hole and the third limiting hole at the same time, and the length of the second positioning pin is less than or equal to the length of the second limiting hole; The control part, the first positioning pin, and the second positioning pin can all be adsorbed by a magnet; The method further includes: When opening the micro-valve, heating the isolating substance into a liquid phase, bringing an external magnetic rod device close to the first limiting hole and the second limiting hole, sucking the first positioning pin into the first limiting hole, controlling the control part to move to the second end of the track by the magnetic rod device, communicating the second limiting hole with the third limiting hole, the magnetic rod device leaving the microfluidic chip or losing magnetic force due to power-off, and the second positioning pin extending into the third limiting hole under the action of gravity; When closing the micro-valve, heating the isolating substance into a liquid phase, bringing an external magnetic rod device close to the first limiting hole and the second limiting hole, sucking the second positioning pin into the second limiting hole, controlling the control part to move to the first end of the track by the magnetic rod device, communicating the first limiting hole with the third limiting hole, the magnetic rod device leaving the microfluidic chip or losing magnetic force due to power-off, and the first positioning pin extending into the third limiting hole under the action of gravity.

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