Microfluidic chip and detection device and control method thereof

Abstract

The present invention provides a microfluidic chip, a detection device, and a control method thereof. The microfluidic chip includes a device body, a channel formed within the device body and open at one end, a pushing unit disposed outside the channel opening for pushing a reaction reagent and a sealing liquid into the channel; a closed space is formed between the end of the channel away from the opening and the pushing end of the pushing unit, the closed space containing a reaction reagent, an air column, and a sealing liquid for sealing the reaction reagent, the reaction reagent, the air column, and the sealing liquid being disposed sequentially from the end of the channel away from the opening toward the channel opening; a valve body is disposed on the channel wall, the valve body being configured to melt upon heating and solidify within the channel after melting, thereby dividing the channel into two mutually unconnected parts, the melting point of the valve body material being higher than the temperature at which the reaction reagent reacts.

Description

Technical Field

[0001] The invention relates to a microfluidic chip and a detection device and a control method thereof, and belongs to the field of microfluidic chips. Background Art

[0002] Microfluidic chips can effectively accommodate fluids at the micron scale, enabling unique analytical capabilities. Currently, research on these chips is expanding, and their application in medical testing is gaining significant attention. Ensuring more accurate and robust test results is crucial, and maintaining the airtightness of microfluidic chips is crucial. Maintaining good airtightness within the chip plays a crucial role in protecting reagent storage, preventing interference, preventing contamination, and improving test accuracy.

[0003] Microvalves are a key technology for controlling fluid flow in microfluidic chips. The microvalve's configuration and opening and closing processes must ensure long-term airtightness within the chip. Current microvalves utilize materials such as paraffin. For example, heating a paraffin microvalves can adjust the valve from a normally closed state to an open state, thereby achieving a valve state change.

[0004] However, due to its low melting point, paraffin microvalves easily mix with the fluid during opening and closing, contaminating the reactants. Furthermore, the reagent reaction temperature within the microfluidic chip can reach 100°C. By this time, the paraffin valve has melted, losing its function as a sealing pipe. Consequently, the valve cannot be closed during the reagent reaction, and the airtightness within the chip cannot be guaranteed, potentially contaminating the reagents. Summary of the Invention

[0005] The problem to be solved by the present invention is that paraffin microvalves in the prior art are easily mixed with fluids during opening and closing, thereby contaminating reaction reagents. A microfluidic chip, a detection device and a control method thereof are provided.

[0006] To solve the above technical problems, the present invention adopts a technical solution: a microfluidic chip, comprising a device body, a channel formed in the device body and open at one end, wherein a pushing unit is provided outside the channel opening for pushing a reaction reagent and a sealing liquid into the channel;

[0007] A closed space is formed between the end of the channel away from the opening and the pushing end of the pushing unit, and the closed space contains a reaction reagent, an air column, and a sealing liquid for sealing the reaction reagent. The reaction reagent, the air column, and the sealing liquid are arranged in sequence from the end of the channel away from the opening to the channel opening; a receiving groove is formed on the lower wall of the channel, and the sample to be tested is accommodated in the receiving groove;

[0008] The channel wall is provided with a valve body, which is used to melt after being heated and solidify in the channel after melting, thereby separating the gas column into two parts that are not connected to each other. The melting point of the valve body material is higher than the temperature of the reaction reagent during reaction. The receiving groove is located between the valve body and the channel opening;

[0009] When the pushing unit is not in action, the first position is located between the pushing end of the pushing unit and the outermost receiving groove.

[0010] In the present invention, when the pushing unit is not in action, the first position is between the pushing end of the pushing unit and the outermost holding groove, so that the reaction reagent can enter the holding groove for storage. The pushing unit can be used to push the reaction reagent, the gas column and the sealing liquid to the inside of the channel, so that the sealing liquid is located above the holding groove to seal the reaction reagent. After the pushing is completed, the gas column can be separated into two parts that are not connected to each other after the melted valve body is solidified by heating, thereby completely blocking the channel at the position of the gas column. During the study, the applicant found that since heating is required during the reaction, if the valve body is not sealed, the sealing liquid will expand due to the heat and squeeze the gas column to the left, so that the sealing liquid may move left and right in the direction of channel extension, making its state unstable, which may affect the reaction between the reaction reagent and the sample being tested. In the present invention, since the valve body is sealed, the sealing liquid is enclosed in the closed space between the valve body and the pushing end of the pushing unit, so that its range of movement is limited, so that it can be in a thermodynamically stable state to avoid affecting the test results. During their research, the applicant discovered that if there are reagents or sealing oil in the pipeline, the heated vaporization of the reagents and the heated flow of the oil will increase the difficulty of sealing the valve body. By providing an air column, the valve body can be sealed to block the channel at the location of the air column, thereby facilitating sealing, and the sealing process will not contaminate the reagents. Because the melting point of the valve body material is higher than the temperature at which the reagents react (generally 100°C), the valve body will not melt when the temperature at which the reagents react is reached. Heating the valve body causes it to melt and seal, thereby achieving closure of the valve body, ensuring the airtightness inside the chip and preventing contamination of the reagents.

[0011] Furthermore, the number of the containing slots is not less than 2, the containing slots are spaced apart along the extending direction of the channel, and the samples to be tested in the containing slots are the same or different samples.

[0012] The receiving grooves are spaced apart along the extending direction of the channel, and the reaction reagent in one receiving groove is separated from the reaction reagent in the adjacent receiving groove by a sealing liquid.

[0013] Furthermore, the sealing liquid is a liquid having a boiling point higher than that of the reaction reagent.

[0014] In the present invention, the reaction reagent generally needs to be heated when reacting with the sample to be tested, so the heated reaction reagent is likely to generate bubbles on the upper surface of the reaction reagent. By setting the sealing liquid to a liquid with a boiling point higher than that of the reaction reagent, the bubbles can be blocked, thereby preventing the reaction reagent from volatilizing.

[0015] Furthermore, the valve body is made of opaque material, the valve body is arranged on the inner wall surface of the device body, and at least one side wall of the device body located outside the valve body is made of translucent material.

[0016] In the present invention, through the above-mentioned arrangement, when heating is performed using an external light heating unit (such as a laser heating unit), at least one side wall on the outside of the valve body is made of a light-transmitting material, and therefore does not absorb heat and will not be deformed due to the irradiation of the heating unit; while the valve body is made of an opaque material and can absorb heat, thereby causing the valve body to melt due to the heat and block the channel.

[0017] Furthermore, the valve body and the device body are both made of plastic materials, the opaque material is dark plastic, and the translucent material is transparent plastic.

[0018] Furthermore, the valve body includes a first sub-valve body and a second sub-valve body which are arranged opposite to each other on both sides of the channel extending direction;

[0019] The side wall of the device body located outside the first sub-valve body and the side wall located outside the second sub-valve body are made of light-transmitting material.

[0020] Furthermore, a first groove and a second groove are provided on the wall of the device body facing the channel. The first groove and the second groove are arranged opposite to each other on both sides of the channel extension direction. The first sub-valve body and the second sub-valve body are respectively accommodated and fixed in the first groove and the second groove.

[0021] In the present invention, by accommodating and fixing the first and second sub-valve bodies in the first and second grooves, respectively, the first and second sub-valve bodies can only move toward one side of the channel when heated and melted, thereby facilitating their movement toward each other. The melted first and second sub-valve bodies then work together to block the channel. The provision of the first and second grooves also avoids excessive obstruction to the flow of liquid in the channel.

[0022] Furthermore, an annular groove is formed on the wall of the channel, surrounding the channel, and the valve body is annular and accommodated in the annular groove. Furthermore, because the valve body is annular, heating can be achieved by simply placing a heating unit on the outside of the side wall of the device body made of a light-transmitting material.

[0023] The present invention also provides a microfluidic chip detection device, which includes a control unit and a detection unit for detecting the position of the air column of the microfluidic chip to be detected as described in any of the above items in the channel of the microfluidic chip to be detected. The control unit and the detection unit are both arranged on the outside of the microfluidic chip to be detected, and the output end of the detection unit and the control end of the pushing unit of the microfluidic chip to be detected are electrically connected to the control unit respectively.

[0024] By setting up a detection unit, it is possible to determine when the gas column reaches the position facing the valve body, so that the pushing unit can be stopped when the gas column faces the valve body, thereby facilitating the sealing of the valve body.

[0025] In a preferred technical solution, the detection unit is used to detect the position of the pushing end of the pushing unit.

[0026] In the present invention, since the channel size, the volume of the sealing liquid, the volume of the reaction reagent, and the speed of the pushing unit can all be determined, the position of the air column can be estimated by detecting the position of the pushing end.

[0027] In a preferred technical solution, the detection unit is a visual detection unit, and an image acquisition end of the visual detection unit is positioned toward the channel. In a preferred technical solution, at least the portion of the device body located between the visual detection unit and the channel is made of a transparent material, and the visual detection unit can distinguish the color and / or brightness difference between the gas column and the reaction reagent, and the color and / or brightness difference between the gas column and the sealing liquid.

[0028] In the present invention, through the above arrangement, the visual detection unit can detect the position of the interface between the gas column and the reaction reagent, and the position of the interface between the gas column and the sealing liquid, thereby detecting the position of the gas column.

[0029] The present invention also provides a microfluidic chip control method, wherein the controlled microfluidic chip is any one of the microfluidic chips described above;

[0030] The microfluidic chip control method comprises the following steps:

[0031] Step (A): pushing the reaction reagent, gas column and sealing liquid into the inner side of the channel;

[0032] Step (B): If it is determined that the valve body is between the first position and the second position, stopping pushing;

[0033] Step (C): heating the valve body for a preset time so that the valve body melts after being heated and solidifies in the channel after melting, thereby dividing the channel into two parts that are not connected to each other.

[0034] The advantages and positive effects of the present invention are:

[0035] 1. After the valve body is closed, the inside of the chip can maintain a high degree of airtightness for a long time, which is stable and reliable;

[0036] 2. The overall manufacturing process of the valve body is simplified, the valve body and the microfluidic chip are easier to integrate, which reduces the production cost of the chip and is suitable for mass production;

[0037] 3. The normally open valve closes quickly, and the valve body can be closed in as short as 0.5s;

[0038] 4. The moving position of the gas column is visualized, and the control is precise and fast;

[0039] 5. The use of an external heating unit makes the power source and the chip independent, which reduces the difficulty of chip processing and production, makes the installation and removal of the chip in the instrument more flexible during testing, and improves the testing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0041] Figure 1 Schematic diagram of the cross-sectional structure of the microfluidic chip when the valve body of Examples 1 and 2 of the present invention is open and the pushing unit is not actuated and is in the initial state;

[0042] Figure 2 Schematic diagram of the cross-sectional structure of the microfluidic chip when the valve body of embodiments 1 and 2 of the present invention is open and the valve body 100 is located between the first position and the second position;

[0043] Figure 3 Schematic diagram of the cross-sectional structure of the microfluidic chip when the valve body is closed according to Example 1 of the present invention;

[0044] Figure 4 for Figure 2 AA cross-sectional view of ;

[0045] Figure 5 for Figure 3 BB cross-sectional diagram;

[0046] Figure 6 For Example 2 of the present invention Figure 2 AA cross-sectional view of ;

[0047] Figure 7 is a schematic three-dimensional cross-sectional view of the device body according to embodiment 2 of the present invention;

[0048] Figure 8 Flowchart of the working process of the microfluidic chip control method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0050] Example 1

[0051] like Figure 1-5 As shown, the present invention provides a microfluidic chip, comprising a device body 10 and a channel 6 formed in the device body 10 and open at one end.

[0052] A pushing unit 3 is provided outside the opening of the channel 6 to push the reaction reagent 7 and sealing liquid 4 into the channel 6. A barrel 31 is provided on the device body 10. The pushing unit 3 can slide along the inner wall of the barrel 31 toward the opening of the channel 6, thereby pushing the reaction reagent 7 and sealing liquid 4 into the channel 6. The space enclosed by the barrel 31, the outer wall of the device body 10, and the pushing end of the pushing unit 3 is in communication with the channel 6.

[0053] A closed space is formed between the end of the channel 6 away from the opening and the pushing end of the pushing unit 3. The closed space contains a reaction reagent 7, a sealing liquid 4 for sealing the reaction reagent 7, and an air column 5 arranged between the reaction reagent 7 and the sealing liquid 4. The reaction reagent 7, the air column 5, and the sealing liquid 4 are arranged in sequence from the end of the channel 6 away from the opening to the opening of the channel 6.

[0054] A receiving groove 61 (also called a microchamber) is formed on the lower wall of the channel 6 , and the sample to be tested is received in the receiving groove 61 .

[0055] The wall of channel 6 is provided with a valve body 100. This valve body 100 is designed to melt upon heating and solidify within channel 6 after melting, thereby separating the gas column 5 into two mutually disconnected portions, thereby separating channel 6 into two mutually disconnected portions. The melting point of the material of valve body 100 is higher than the reaction temperature of the reagents. The receiving groove 61 is located between valve body 100 and the opening of channel 6.

[0056] When the pushing unit 3 is not in action, the first position is between the pushing end of the pushing unit 3 and the outermost receiving groove 61 .

[0057] The number of the receiving slots 61 may be no less than 2, and the receiving slots 61 are spaced apart along the extending direction of the channel. The samples to be tested in the receiving slots 61 may be the same or different samples.

[0058] like Figure 1-4 As shown, the device body 10 is surrounded by sidewalls 101, 102, 103, and 104. During processing, each sidewall can be an independent structure and can be formed by vacuum bonding or conventional bonding followed by vacuum pumping to form the device body 10, thereby creating a vacuum-sealed environment. A channel 6 (i.e., a microfluidic channel) is formed between sidewalls 101, 102, 103, and 104, and a valve body 100 is disposed within the channel 6.

[0059] In this embodiment 1, the valve body 100 includes a first sub-valve body 1 and a second sub-valve body 2 which are arranged opposite to each other on both sides of the extending direction of the channel 6;

[0060] The valve body 100 can be made of an opaque material and is positioned on the inner wall of the device body 10. At least one sidewall of the device body 10, located outside the valve body 100, is made of a translucent material. In this embodiment, the sidewall 101 located outside the first sub-valve body 1 and the sidewall 102 located outside the second sub-valve body 2 of the device body 10 are made of a translucent material. Sidewalls 103 and 104 can be made of either translucent or opaque materials.

[0061] Since the side walls 101 and 102 are made of light-transmitting material, they do not absorb heat. When the first sub-valve body 1 and the second sub-valve body 2 melt, they transfer heat to the side walls 101 and 102 respectively, and when solidified, they adhere to the side walls 101 and 102 respectively.

[0062] The valve body 100, sidewalls 103, 104, 101, and 102 can all be made of a polymer plastic material. The polymer plastic material can have a melting point above 100°C, preferably PC or PP. The opaque material can be a dark plastic, while the translucent material can be a transparent plastic. Because the valve body 100 is made of a polymer plastic material, it is not easily affected by environmental changes, does not contaminate reagents, and is stable and reliable.

[0063] Sidewalls 103 and 104 can be made of a dark, opaque material, preferably black. Valve body 100, consisting of a first sub-valve body 1 and a second sub-valve body 2, is positioned above and below the channel where fluid flow is to be controlled. It is made of the same material as sidewalls 103 and 104 and is not integrally formed with them. By using the chip's own material as the valve body, the valve body and chip can be integrally formed. When the valve body is closed, the chip interior maintains a high degree of airtightness for a long time.

[0064] In this embodiment, the side wall 101 is provided with the first groove on the side facing the channel 6, and the side wall 102 is provided with the second groove on the side facing the channel 6. The first groove and the second groove are arranged opposite to each other on both sides of the extension direction of the channel 6, and the first sub-valve body 1 and the second sub-valve body 2 are respectively accommodated and fixed in the first groove and the second groove.

[0065] The first sub-valve body 1 can be integrally formed with the side wall 101 , and the second sub-valve body 2 can be integrally formed with the side wall 102 .

[0066] When the push unit is not in action (i.e., in the initial state), the positions of the reaction reagent 7, the gas column 5, and the sealing liquid 4 can be the following two situations:

[0067] Case 1: If Figure 1 As shown, the reaction reagent 7 and the gas column 5 are located in the channel 6, and the sealing liquid 4 is located outside the channel 6. That is, the reaction reagent 7 is contained between the gas column 5 and the end of the channel 6 away from the opening, and the containing groove 61 contains the reaction reagent 7;

[0068] Case 2: There is a vacuum state between the end of the channel 6 away from the opening and the reaction reagent 7 .

[0069] exist Figure 1 In the initial state shown, the valve body 100 is in a normally open state, and the reaction reagent 7 can enter and be contained in the containing groove 61 .

[0070] The pushing unit 3 pushes the reaction reagent 7, the gas column 5 and the sealing liquid 4 to the inner side of the channel 6. When the valve body 100 is between the first position and the second position, the pushing unit 3 stops moving. Figure 2 At this point, the receiving tanks 61 still contain reaction reagents 7, and above each receiving tank 61 is a sealing liquid 4. The receiving tanks 61 are spaced apart along the channel extension direction, and the reaction reagent 7 in one receiving tank 61 is separated from the reaction reagent 7 in the adjacent receiving tank by the sealing liquid 4.

[0071] exist Figure 3 In the state shown, the valve body 100 is closed, and in this state, the reaction reagent 7 in the receiving tank 61 can react with the sample to be detected. Figure 3 As shown, when the valve body 100 is solidified in the channel 6, the valve body 100 separates the gas column 5 into two parts that are not connected to each other. Figure 3In the example, after the first and second sub-valve bodies 1 and 2 melt, they flow toward the sides of the fluid channel and solidify, blocking the channel. Due to the small amount of material in the center, a cavity forms. This cavity does not affect the sealing of the channel. After the first and second sub-valve bodies 1 and 2 melt, the melt flow is not only affected by gravity, but also by the fact that the sidewalls 103 and 104 outside the valve body 100 are unheated and solid, leaving no room for the melt to flow. Therefore, the molten first and second sub-valve bodies 1 and 2 can only flow toward one side of channel 6, thereby sealing (completely blocking) the channel. Figure 3 In the embodiment, there is a sealing liquid 4 above each holding tank 61. Therefore, when the reaction reagent 7 in each holding tank 61 reacts with the sample to be detected, the reaction reagents 7 in each holding tank 61 will not affect each other, and therefore will not affect the detection results of the sample to be detected in each holding tank 61 (will not affect the fluorescent labeling results).

[0072] The reaction reagent 7 typically requires heating when reacting with the sample being tested. This heating of the reagent 7 can easily generate bubbles on the surface of the reagent 7. By using a sealing liquid 4 with a higher boiling point than the reagent 7, bubbles can be blocked, thereby preventing the reagent 7 from volatilizing. The sealing liquid 4 is preferably sealing oil.

[0073] During the reaction, if the valve body 100 is not sealed, the sealing liquid 4 will expand due to the heat and squeeze the gas column 5 to the left, so that the sealing liquid 4 may move left and right in the direction of the channel extension, making its state unstable and possibly affecting the reaction between the reaction reagent 7 and the sample being tested.

[0074] exist Figure 3 In the embodiment, since the valve body 100 is sealed, the sealing liquid 4 is enclosed in the closed cavity between the valve body 100 and the pushing end of the pushing unit 3, so that its range of movement is limited, thereby keeping it in a thermodynamically stable state and avoiding affecting the detection results.

[0075] A control unit and a detection unit for detecting the position of the gas column 5 in the channel 6 are provided on the outside of the device body 10. The control unit can be a PLC controller, a single chip microcomputer, a DSP or an FPGA.

[0076] The detection unit is used to detect the position of the pushing end of the pushing unit 3. Since the position of the pushing unit, the channel size, the volume of the reaction reagent, the volume of the gas column, the volume of the sealing liquid, and the speed of the pushing unit can all be determined, it is possible to estimate the position to which the pushing unit needs to move from the start of operation until the gas column is directly opposite the valve body (i.e., one end of the gas column is located between the valve body and the end of the channel away from the opening, and the other end of the gas column is located between the valve body and the channel opening), so that the valve body 100 can be heated after the pushing unit stops.

[0077] The detection unit can also be a visual detection unit, and the image acquisition end of the visual detection unit is set toward the channel 6. At least the portion of the device body 10 located between the visual detection unit and the channel 6 is made of transparent material. The color difference and / or brightness difference between the gas column 5 and the reaction reagent 7 can be distinguished by the visual detection unit, and the color difference and / or brightness difference between the gas column 5 and the sealing liquid 4 can be distinguished by the visual detection unit.

[0078] A heating unit 50 for heating the valve body 100 is provided on the outside of the device body 10 at a position corresponding to the valve body 100. The control end, detection unit output end, and push unit control end of the heating unit 50 are electrically connected to the control unit. The heating unit 50 can be a laser heating unit. The heating unit 50 for heating the first sub-valve body 1 can be close to the outer wall of the side wall 101 or in contact with the outer wall of the side wall 101. The heating unit 50 for heating the second sub-valve body 2 can be close to the outer wall of the side wall 102 or in contact with the outer wall of the side wall 102. The laser can heat the first sub-valve body 1 and the second sub-valve body 2 respectively through the transparent side walls 101 and 102. The laser can use non-contact heating. The side walls covering the sub-valve bodies are heated by an external heating unit, causing the material to melt and solidify, thereby sealing the pipeline. The valve body 100 is made of opaque material, which can absorb laser energy and melt. The selected laser has a specific wavelength, and the reagent is not affected by light.

[0079] In the present invention, through the above arrangement, the control unit can determine whether the air column has reached a specified position based on the position of the air column in the channel detected by the detection unit. When the air column reaches the specified position, the control unit stops the push unit and controls the heating unit to heat the air, thereby achieving automatic control of the device. The heating end of the heating unit is in contact with or adjacent to a position on the outside of the device body corresponding to the valve body.

[0080] In a preferred embodiment, the heating unit is a laser heating unit, the valve body is arranged on the inner wall of the device body, the valve body is made of opaque material, and at least the portion of the device body located between the valve body and the heating unit is made of translucent material.

[0081] In the present invention, after the valve body is closed, the interior of the chip can maintain a high degree of airtightness for a long time.

[0082] The heating unit may be a laser heating unit, preferably a blue-violet laser light source, and the parameters of the heating unit may be: power of 1-5W, wavelength of 450nm, and heating time of 0.5-2s.

[0083] The present invention identifies the position of the gas column 5 through a visual detection unit, and then controls the gas column 5 to move to a specified position. The control of the moving position of the gas column 5 is accurate and rapid. The presence of the gas column 5 is conducive to the closing of the valve body 100. The valve body 100 is closed by laser heating the materials on both sides of the pipeline to melt them. If there are reagents or sealing oils in the pipeline, the heated vaporization of the reagents and the heated flow of the oil will increase the difficulty of sealing, so the gas column 5 is provided to facilitate sealing. The collection head of the visual detection unit can be set toward the channel, and the collection head can be oriented perpendicular to the side wall. The visual detection unit can use CCD or CMOS.

[0084] The valve body of the present invention is stable and reliable in opening and closing, simple to operate, can be implanted in a tiny microfluidic chip, and has no pollution to reagents. It can maintain a long-term stable vacuum degree inside the chip before use, and after the valve body is closed, the inside of the chip can maintain a high degree of airtightness for a long time.

[0085] like Figure 8 As shown, the present invention also provides a microfluidic chip control method, wherein an air column 5 is provided between the reaction reagent 7 and the sealing liquid 4;

[0086] The closed space contains a reaction reagent 7, an air column 5, and a sealing liquid 4 for sealing the reaction reagent 7. The reaction reagent 7, the air column 5, and the sealing liquid 4 are arranged in sequence from the end of the channel 6 away from the opening to the opening of the channel 6.

[0087] The microfluidic chip control method comprises the following steps:

[0088] Step (A): Push the reaction reagent 7, gas column 5 and sealing liquid 4 into the inner side of the channel;

[0089] Step (B): If it is determined that the valve body 100 is between the first position and the second position, then the pushing is stopped;

[0090] Step (C): The valve body 100 is heated for a predetermined time, so that the valve body 100 melts and solidifies in the channel 6 after melting, thereby separating the channel 6 into two disconnected parts. The predetermined time may be 0.5-2 seconds.

[0091] The first position and the second position are respectively the boundary between the gas column 5 and the reaction reagent 7 and the boundary between the gas column 5 and the sealing liquid 4. By detecting the first position and the second position, it can be determined whether the valve body 100 is located between the first position and the second position.

[0092] The working process of the present invention is as follows: a plunger (i.e., a pushing unit 3) is connected to the upper end of the chip channel 6, and a sealing liquid 4 is stored in the plunger pipeline. The sealing liquid 4 can be a high-boiling point heat-conducting oil such as mineral oil, which is used to seal the reaction reagent 7. The front end of the sealing liquid 4 is in contact with the channel 6 for a 10-15 mm long gas column 5. The purpose of providing the gas column 5 is to facilitate the melting seal of the valve body 100. After the reaction reagent 7 enters the channel 6, the plunger is pressed down, and the gas column 5 moves as the plunger is pressed down, pushing the reaction reagent 7 forward. The visual detection unit can continuously identify the position of the gas column 5 by identifying the interface between the gas column 5 and the sealing liquid 4 and the interface between the gas column 5 and the reaction reagent 7, and feed back to the control system. The control system judges the result. When the gas column 5 moves close to the specified position, the control system controls the motor to brake and decelerate until the gas column 5 moves to the specified pipeline position at the lower end of the valve body 100. The motor brake stops and the plunger 3 stops pressing down. At this point, the heating unit 50 is adjusted to heat the first and second sub-valve bodies 1 and 2 simultaneously, causing the valve body material of both parts to partially melt and flow into the channel. Under the pressure of the device body 10, they connect and solidify at the channel, blocking the transverse section of the pipeline and thus terminating the channel. This valve body can achieve a "normally open / normally closed" function, maintaining a high degree of airtightness within the chip for a long time. The push unit 3 can be a plunger, which is a well-known technology in the field and will be understood by those skilled in the art.

[0093] Example 2

[0094] like Figure 1-2 、 Figure 6 、 Figure 7 As shown, the difference between this embodiment 3 and embodiment 1 is that an annular groove 60 is formed on the wall surface of the channel 6, and the annular groove 60 is arranged around the channel 6. The valve body 100 is annular and accommodated in the annular groove 60. At least one sidewall of the device body 10 located outside the valve body 100 is made of a light-transmitting material, that is, at least one of sidewalls 101, 102, 103, and 104 is made of a light-transmitting material. Because the valve body 100 is an integral annular structure, a heating unit 50 need only be provided outside the at least one light-transmitting sidewall to heat the device body 10. Moreover, the annular valve body 100 moves toward the center when heated, making it easier to close the valve body 100 and thus block the channel 6. Figure 7 The figure is a schematic three-dimensional cross-sectional view of the device body obtained by cutting the device body along its cross section.

[0095] Example 3

[0096] This embodiment 3 differs from embodiment 1 in that no detection device is provided, only a timing device. Based on the channel dimensions, the volume of the reaction reagent, the volume of the gas column, the volume of the sealing liquid, and the speed of the push unit, an estimate is made of how long the push unit will need to operate from the start of operation until the gas column 5 reaches a position directly opposite the valve body. This allows the valve body 100 to be heated after the push unit stops.

[0097] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0098] The embodiments of the present invention are described in detail above, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of this patent. After reading this invention, modifications of various equivalent forms of the present invention by those skilled in the art fall within the scope defined by the claims attached to this application. In the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

Claims

1. A microfluidic chip, comprising a device body (10), a channel (6) formed in the device body (10) and open at one end, wherein a pushing unit (3) is provided on the outer side of the opening of the channel (6) for pushing a reaction reagent (7) and a sealing liquid (4) into the inner side of the channel (6); A closed space is formed between the end of the channel (6) away from the opening and the pushing end of the pushing unit (3), wherein the closed space contains a reaction reagent (7), an air column (5), and a sealing liquid (4) for sealing the reaction reagent (7), wherein the reaction reagent (7), the air column (5), and the sealing liquid (4) are arranged in sequence from the end of the channel (6) away from the opening to the opening of the channel (6); a receiving groove (61) is provided on the lower wall of the channel (6), and a sample to be tested is contained in the receiving groove (61); It is characterized in that The wall of the channel (6) is provided with a valve body (100), the valve body (100) is used to melt after being heated and solidify in the channel (6) after melting, thereby separating the gas column (5) into two parts that are not connected to each other, the melting point of the material of the valve body (100) is higher than the temperature of the reaction reagent (7) during reaction, and the receiving groove (61) is located between the valve body (100) and the opening of the channel (6); When the pushing unit (3) is not in motion, the first position is located between the pushing end of the pushing unit (3) and the outermost receiving groove (61); the first position is the intersection of the gas column (5) and the reaction reagent (7).

2. The microfluidic chip according to claim 1, characterized in that The number of the containing grooves (61) is not less than 2, and the containing grooves (61) are arranged at intervals along the extension direction of the channel. The samples to be tested in the containing grooves (61) are the same or different samples.

3. The microfluidic chip according to claim 1, characterized in that The sealing liquid (4) is a liquid having a boiling point higher than that of the reaction reagent (7).

4. The microfluidic chip according to any one of claims 1 to 3, characterized in that The valve body (100) is made of opaque material and is arranged on the inner wall surface of the device body (10); at least one side wall (101, 102) of the device body (10) located outside the valve body (100) is made of translucent material.

5. The microfluidic chip according to claim 4, characterized in that: The valve body (100) and the device body (10) are both made of plastic materials, the opaque material is dark plastic, and the translucent material is transparent plastic.

6. The microfluidic chip according to claim 4, characterized in that: The valve body (100) comprises a first sub-valve body (1) and a second sub-valve body (2) which are arranged opposite to each other on both sides of the channel (6) in the extension direction; the side wall (101) located outside the first sub-valve body (1) and the side wall (102) located outside the second sub-valve body (2) of the device body (10) are made of light-transmitting material.

7. The microfluidic chip according to claim 6, characterized in that: A first groove and a second groove are provided on the wall of the device body (10) facing the channel (6). The first groove and the second groove are arranged opposite to each other on both sides of the extension direction of the channel (6). The first sub-valve body (1) and the second sub-valve body (2) are respectively accommodated and fixed in the first groove and the second groove.

8. The microfluidic chip according to claim 4, characterized in that: An annular groove (60) is provided on the wall surface of the channel (6), and the annular groove (60) is arranged around the channel (6). The valve body (100) is an annular structure and is accommodated in the annular groove (60).

9. A microfluidic chip detection device, characterized in that: The microfluidic chip detection device comprises a control unit and a detection unit for detecting the position of the gas column (5) of the microfluidic chip according to any one of claims 1 to 8 in the channel (6), wherein the control unit and the detection unit are both arranged outside the microfluidic chip, and the output end of the detection unit and the control end of the pushing unit (3) of the microfluidic chip are electrically connected to the control unit respectively.

10. The microfluidic chip detection device according to claim 9, characterized in that: The detection unit is used to detect the position of the pushing end of the pushing unit (3); or the detection unit is a visual detection unit, and the image acquisition end of the visual detection unit is arranged toward the channel (6).

11. A microfluidic chip control method, characterized in that: The controlled microfluidic chip is the microfluidic chip according to any one of claims 1 to 8; The microfluidic chip control method comprises the following steps: Step (A): pushing the reaction reagent (7), the gas column (5) and the sealing liquid (4) into the inner side of the channel (6); Step (B): if it is determined that the valve body (100) is located between the first position and the second position, stopping pushing; Step (C): heating the valve body (100) for a preset time, so that the valve body (100) melts after being heated and solidifies in the channel (6) after melting, thereby separating the channel (6) into two parts that are not connected to each other; The second position is the boundary between the gas column (5) and the sealing liquid (4).

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