A microfluidic chip temperature control fixture and its application method

Abstract

This invention provides a microfluidic chip temperature control fixture and its usage method, including a fixture base for mounting the entire fixture; a clamping groove is formed in the middle of the fixture base, and a chip stage is supported inside the clamping groove; a heating film and a temperature sensor for precise temperature control of the microfluidic chip are disposed inside the chip stage; a fixture cover for mounting the microfluidic chip is hinged to one side of the fixture base via a connecting shaft, and the fixture cover can rotate around the connecting shaft and press against the chip stage; a pressure head for pressing and locking the fixture cover is hinged to the other side of the fixture base. This fixture facilitates the installation and removal of microfluidic chips, and allows for easy adjustment of their installation position. The overall structure is simple and easy to operate; it also enhances the sealing performance of the circulating fluid path and achieves temperature control of the microfluidic chip, facilitating rapid cooling and improving work efficiency.

Description

Technical Field

[0001] This invention relates to the field of microfluidic chip technology, and in particular to a microfluidic chip temperature control fixture and its usage method. Background Technology

[0002] Microfluidic chips are platforms for manipulating fluids at the micrometer scale. Due to this characteristic, microfluidic chips can perform micro-operations that are difficult to achieve using conventional methods.

[0003] The fully automated in situ hybridization analyzer for liquid-based cells developed in our laboratory uses a microfluidic chip as the reaction carrier and can perform a complete automated fluorescence in situ hybridization process that integrates separation, purification, fixation, and FISH hybridization of body fluid samples.

[0004] The microfluidic chip used in the fully automated in situ hybridization analyzer requires a matching placement platform to connect the chip to the circulating liquid path for liquid inlet and outlet, and to perform operations such as chip fixation and temperature control.

[0005] Traditional placement platforms use bolts or adhesives to fix microfluidic chips. Using bolts is cumbersome and it is difficult to control the preload of the bolts. Using adhesives makes it impossible to disassemble the chip, and the fluidity of the adhesive can easily contaminate the chip and affect the experimental results.

[0006] Existing microfluidic chip fixtures, such as the one disclosed in Chinese Patent Publication No. CN115635439A, while not requiring bolts or adhesives for fixation, suffer from problems such as slow cooling speed, the need for manual adjustment of the microfluidic chip's position on the fixture, and the lack of foolproof design. Another example is a fluorescence in situ hybridization (FISH) chip fixture disclosed in Chinese Patent Publication No. CN218516762U, which includes a fixing plate, a chip slot, and a chip fixing device. This fixture can easily fix the microfluidic chip, but it does not solve the problems of lacking foolproof design, slow cooling speed, and insufficient contact between the microfluidic chip and the fixture. Summary of the Invention

[0007] To address the shortcomings of the existing technology, this invention provides a microfluidic chip temperature control fixture and its usage method. This fixture facilitates the installation and removal of microfluidic chips and allows for easy adjustment of their installation position. It features a simple overall structure and convenient operation. Furthermore, it enhances the sealing performance of the circulating fluid path and enables temperature control of the microfluidic chip, facilitating rapid cooling and improving work efficiency.

[0008] To achieve the above-mentioned technical features, the present invention aims to provide a microfluidic chip temperature control fixture, comprising a fixture base for mounting the entire fixture; a clamping groove is provided in the middle of the fixture base, and a chip stage is supported inside the clamping groove; a heating film and a temperature sensor for precise temperature control of the microfluidic chip are disposed inside the chip stage; a fixture cover for mounting the microfluidic chip is hinged to one side of the fixture base via a connecting shaft, the fixture cover being rotatable around the connecting shaft and pressing against the chip stage; a pressure head for pressing and locking the fixture cover is hinged to the other side of the fixture base.

[0009] Preferably, multiple sets of through holes are symmetrically machined on both sides of the fixture base. The through holes are used to pass through bolts and fix the entire fixture base to the instrument base. A first boss is provided on one side of the top of the fixture base. A pressure head is hinged to the first boss by a round pin. A second boss is provided on the other side of the top of the fixture base. An arc-shaped groove is provided in the middle part of the second boss. The fixture cover is hinged to the second boss by a connecting shaft.

[0010] A small fan for cooling is fixed on the fixture base and close to the inner wall of the second protrusion.

[0011] Preferably, the fixture cover includes a chip base, a chip cover, a spring, a spring plate, and a sample loading slot; one end of the chip base is hinged to the fixture base, the chip base and the chip cover are fixed by bolts, and a chip loading slot is formed between the chip base and the chip cover, and the microfluidic chip can be inserted into the chip loading slot and can move up and down.

[0012] Preferably, the chip cover is machined with a strip-shaped through groove, and a spring for pressing the microfluidic chip is placed in the strip-shaped through groove. The spring is pressed and fixed by a spring plate, and the spring plate is fixed to the top of the chip cover by bolts and located at the position of the strip-shaped through groove.

[0013] Preferably, the chip base has a protruding block at the top and at the end where the pressure head is located. The top of the protruding block has a circular hole for engaging with a spring pin mounted on the pressure head, and the edge of the protruding block has a beveled notch for facilitating the passage of the spring pin.

[0014] Preferably, the chip stage includes a heating block mounting plate, a heating block, a heating film, a temperature sensor, a flared mouth, a thin steel cylinder, and an inverted conical connector; the heating block mounting plate is located in the middle of the fixture base, the heating block is fixedly mounted on the top of the heating block mounting plate, a planar groove is provided at the bottom of the heating block, the heating film is fixed in the planar groove by adhesive, a cylinder is provided in the middle of the planar groove, a notch is provided on the side of the cylinder, a temperature sensor is provided inside the cylinder, and the lead wire of the temperature sensor is led out from the notch.

[0015] Preferably, the heating film adopts a flexible structure, with a through hole in the middle of the heating film for passing through the cylinder, and a wire hole in the middle of the heating block mounting plate, through which the wires of the heating film and the temperature sensor can be led out.

[0016] Preferably, the heating block mounting plate is provided with four through holes, which correspond to the four channels of the microfluidic chip respectively. The end of the through hole is provided with a thread, and an inverted conical joint is installed through the thread. A thin steel cylinder is installed inside the inverted conical joint, and the top of the thin steel cylinder extends out of the heating block by a small section. The flared mouth is fitted onto the top of the thin steel cylinder.

[0017] Preferably, the sample loading slot has four sample loading holes, which are fixed to the microfluidic chip with adhesive. The four sample loading holes are respectively aligned with the four inlets of the microfluidic chip. The outlet of the microfluidic chip is connected to the flared end. The upper cover of the fixture is machined with a sample loading slot notch for inserting the sample loading slot. O-rings are provided around the four sample loading holes. A rubber ring groove is provided at the top of the lower part of the sample loading slot, and a rubber ring is installed on the rubber ring groove. When the microfluidic chip is loaded, the rubber ring contacts the chip cover, which plays a buffering role. The sample loading slot is fixed to the microfluidic chip with waterproof sealing double-sided tape, and the O-ring at the lower end of the sample loading slot plays a role in strengthening the seal.

[0018] Preferably, a method for using a microfluidic chip temperature control fixture is provided, comprising the following steps:

[0019] Step 1: Raise the top cover of the fixture to a certain angle. Then, insert the microfluidic chip along the clamping groove between the chip base and the chip top cover. When the microfluidic chip touches the curved edge of the spring, continue to push it to the left. The spring will undergo elastic deformation under the force and generate a downward elastic force on the microfluidic chip, making the microfluidic chip stick tightly to the chip base. Continue to push it to the left, and the microfluidic chip will reach the leftmost end of the chip base.

[0020] Step 2: Insert the sample loading slot into the fixture cover, ensuring that the sample loading hole of the sample loading slot is located at the inlet of the microfluidic chip. At the same time, press the microfluidic chip to ensure a tight seal between the two. At this time, due to the limiting effect of the chip clamping slot of the fixture cover and the sample loading slot notch of the chip cover, the sample loading slot fixed on the microfluidic chip is exactly located in the sample loading slot notch of the chip cover. The chip is in the optimal position and can only move up and down, not in all directions.

[0021] Step 3: Close the fixture cover. The microfluidic chip will contact the chip stage. Continue to close the fixture cover. The chip stage will exert an upward force on the microfluidic chip. The spring on the chip cover is compressed under this force and makes the microfluidic chip come into close contact with the heating block on the chip stage. The flared opening on the chip stage connects with the outlet of the microfluidic chip to form a passage. At this time, use the pressure head to lock the fixture cover. The chip loading is complete.

[0022] Step 4: Connect the other end of the thin steel cylinder to the negative pressure pump. In this way, the entire system pathway is formed. The negative pressure pump can generate negative pressure at the outlet of the microfluidic chip, add body fluid samples through the sample loading tank, and then enter the microfluidic chip through the inlet.

[0023] Step 5: When it is necessary to control the temperature of the microfluidic chip, the microfluidic chip is heated by the heating film inside the chip stage. The temperature sensor inside the chip stage detects the temperature of the microfluidic chip in real time. The heating film and the temperature sensor are connected to the temperature control system, thereby achieving precise temperature control of the microfluidic chip. The small fan located on one side of the fixture can accelerate the airflow near the microfluidic chip, shortening the cooling time.

[0024] The present invention has the following beneficial effects:

[0025] 1. The clamp of the present invention can facilitate the installation and removal of microfluidic chips, and can easily adjust their installation position. The overall structure is simple and easy to operate. It also enhances the sealing performance of the circulating fluid path and realizes the temperature control of the microfluidic chip, so as to achieve rapid cooling and improve work efficiency.

[0026] 2. By employing the fixture base of the present invention, a convenient fixed connection can be made between it and the instrument base. Furthermore, a corresponding first boss is used to mount the pressure head, and a corresponding second boss is used to mount the fixture cover.

[0027] 3. The small fan is used to dissipate heat and cool the fixture.

[0028] 4. The spring clips can reliably press the microfluidic chip between the chip base and the chip cover after it is inserted, ensuring that it can only move in the up and down direction.

[0029] 5. The above-described arrangement facilitates heating control of the chip stage via a heating film. Furthermore, the temperature sensor provides timely feedback on the chip stage temperature, enabling precise control of the subsequent heating temperature.

[0030] 6. The downward force provided by the spring contacts ensures that the chip adheres tightly to the chip carrier, resulting in more uniform heating, a tighter connection with the horn, and better sealing.

[0031] 7. The chip can be heated by the heating film inside the chip stage. The temperature sensor inside the chip stage can detect the chip temperature in real time. Both the heating film and the temperature sensor are controlled by a separate control system, thereby achieving precise temperature control of the microfluidic chip. The small fan located on the left end of the fixture can accelerate the airflow near the chip, shortening the cooling time. Attached Figure Description

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0033] Figure 1 This is the first model of the device of the present invention.

[0034] Figure 2 This is the second model of the device of the present invention.

[0035] Figure 3 This is a diagram showing the operational status of the device of the present invention.

[0036] Figure 4 This is a diagram showing the walking state of the device of the present invention.

[0037] Figure 5 This is a diagram of the separation mechanism of the present invention.

[0038] Figure 6 Details of the separation mechanism of the present invention Figure 1 .

[0039] Figure 7 Details of the separation mechanism of the present invention Figure 2 .

[0040] Figure 8 Details of the separation mechanism of the present invention Figure 3 .

[0041] Figure 9 This is a structural diagram of the invention installed on the instrument base.

[0042] Figure 10 This is a diagram of the internal structure of the heating block of the present invention.

[0043] In the diagram: 1-Clamping top cover, 2-Chip stage, 3-Clamping base, 4-Sample loading slot, 5-Spring pressure plate, 6-Spring, 7-Chip top cover, 8-Chip base, 9-Small fan, 10-Pressure head, 11-Flange mouth, 12-Heating block, 13-Temperature sensor, 14-Heating film, 15-Heating block mounting plate, 16-Inverted conical connector, 17-Slim steel cylinder, 18-Microfluidic chip, 19-Inlet, 20-Outlet, 21-Protrusion block, 22-Spring pin, 23-Circular hole, 24-Beveled notch, 25-First boss, 26-Second boss, 27-Arc-shaped groove, 28-Connecting shaft, 29-Through hole, 30-Instrument base, 31-Flat groove, 32-Cylinder, 33-Notch, 34-Sample loading slot notch, 35-Circular pin. Detailed Implementation

[0044] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0045] Example 1:

[0046] See Figure 1-10 A microfluidic chip temperature control fixture includes a fixture base 3 for mounting the entire fixture; a clamping groove is formed in the middle of the fixture base 3, and a chip stage 2 is supported inside the clamping groove; a heating film 14 and a temperature sensor 13 for precise temperature control of the microfluidic chip 18 are disposed inside the chip stage 2; a fixture cover 1 for mounting the microfluidic chip 18 is hinged to one side of the fixture base 3 via a connecting shaft, and the fixture cover 1 can rotate around the connecting shaft and press against the chip stage 2; a pressure head 10 for pressing and locking the fixture cover 1 is hinged to the other side of the fixture base 3. By using the above fixture, the microfluidic chip 18 can be easily clamped and mounted inside the fixture cover 1, and the temperature of the microfluidic chip 18 can be controlled by the chip stage 2.

[0047] Furthermore, multiple sets of through holes 29 are symmetrically machined on both sides of the clamp base 3. These through holes 29 are used to pass bolts and fix the entire clamp base 3 to the instrument base 30. A first boss 25 is provided on one side of the top of the clamp base 3, and a pressure head 10 is hinged to the first boss 25 via a round pin 35. A second boss 26 is provided on the other side of the top of the clamp base 3, and an arc-shaped groove 27 is provided in the middle of the second boss 26. A clamp cover 1 is hinged to the second boss 26 via a connecting shaft 28. The clamp base 3 can be easily fixedly connected to the instrument base 30. The corresponding first boss 25 is used to install the pressure head 10, and the corresponding second boss 26 is used to install the clamp cover 1.

[0048] Furthermore, a small fan 9 for cooling is fixed on the fixture base 3 and close to the inner wall of the second protrusion. The small fan 9 dissipates heat and cools the fixture.

[0049] Furthermore, the fixture cover 1 includes a chip base 8, a chip cover 7, a spring 6, a spring pressure plate 5, and a sample loading slot 4. One end of the chip base 8 is hinged to the fixture base 3, and the chip base 8 and the chip cover 7 are fixed by bolts. A chip loading slot is formed between the chip base 8 and the chip cover 7, and the microfluidic chip 18 can be inserted into the chip loading slot and can move up and down. The fixture cover 1 described above can be used to clamp and fix the microfluidic chip 18.

[0050] Furthermore, a strip-shaped through-slot is machined on the chip cover 7, and a spring 6 for pressing the microfluidic chip 18 is placed in the strip-shaped through-slot. The spring 6 is pressed and fixed by a spring plate 5, which is fixed to the top of the chip cover 7 by bolts and located at the position of the strip-shaped through-slot. The spring 6 can reliably press the microfluidic chip 18 after it is inserted between the chip base 8 and the chip cover 7, ensuring that it can only move in the vertical direction.

[0051] Furthermore, the chip base 8 has a frame structure, and the fixture cover 1 is provided with two strip-shaped through slots. One strip-shaped through slot is used to place the spring 6, and the other strip-shaped slot is used to leave a sample slot notch 34 for loading the sample slot 4 on the chip. The elastic part of the spring 6 is an arched structure. When the spring 6 is subjected to force, the arched structure of the spring 6 will produce elastic deformation. During installation, the arched structure of the spring 6 is placed in the strip-shaped slot, and the spring plate 5 fixes the spring 6 with screws.

[0052] Furthermore, a protruding block 21 is provided on the top of the chip base 8 at the end where the pressure head 10 is located. The top of the protruding block 21 is provided with a circular hole 23 for engaging with a spring pin 22 mounted on the pressure head 10, and the edge of the protruding block 21 is provided with a beveled notch 24 to facilitate the passage of the spring pin 22. After the clamp cover 1 is closed, the pressure head 10 can be rotated to lock the clamp cover 1. At this time, the chip will be in close contact with the chip stage 2.

[0053] Furthermore, by setting a spring pin at the lower end of the pressure head 10, when the clamp cover 1 is in the closed state, gradually rotating the pressure head 10 to close it, the spring pin first contacts the inclined notch of the clamp cover 1. Continuing to rotate the pressure head 10, the spring pin is pushed up by the inclined surface. When the pressure head 10 is fully closed, the spring pin passes over the inclined notch 24 and inserts into the circular hole 23 of the clamp cover 1, causing the pressure head 10 to engage with the clamp cover 1, thereby locking the clamp cover 1. To unlock, pushing the upper end of the pressure head 10 pushes the spring pin up and it disengages from the circular hole into the inclined area. Under the action of elasticity and gravity, the pressure head 10 automatically slides down.

[0054] When loading the microfluidic chip using the aforementioned fixture cover 1, the chip is placed between the chip cover 7 and the chip base 8, with the sample loading slot 4 on the chip facing upwards and aligned with the sample loading slot notch 34 on the chip cover 7. At this point, the chip is pushed into the left end of the fixture cover 1, and the chip contacts the arc-shaped edge of the spring 6. Continuing to push it to the left, the spring 6 undergoes elastic deformation under the force, generating a downward elastic force on the chip, causing the chip to adhere tightly to the chip base 8. Continuing to push it to the left, the chip will reach the leftmost end of the chip base 8. At this point, due to the limiting effect of the chip clamping slot of the fixture cover 1 and the sample loading slot notch of the chip cover 7, the sample loading slot 4 fixed on the chip is exactly located in the sample loading slot notch of the chip cover 7, and the chip is in the optimal position, only able to move up and down, and cannot move in all directions. Then, close the clamp cover 1, and the chip will contact the chip stage 2. Continue to close the clamp cover 1, and the chip stage 2 will exert an upward force on the chip. The spring 6 on the chip cover 7 is compressed under this force and makes the chip and the heating block 12 on the chip stage 2 come into close contact. The horn 11 on the chip stage 2 is connected to the chip outlet to form a passage. At this time, the clamp cover 1 is locked with the pressure head 10, and the chip loading is completed.

[0055] Furthermore, the chip stage 2 includes a heating block mounting plate 15, a heating block 12, a heating film 14, a temperature sensor 13, a flared opening 11, a thin steel cylinder 17, and an inverted conical connector 16. The heating block mounting plate 15 is located in the middle of the fixture base 3. The heating block 12 is fixedly mounted on the top of the heating block mounting plate 15. A planar groove is provided at the bottom end of the heating block 12. The heating film 14 is fixed in the planar groove 31 with adhesive. A cylinder 32 is provided in the middle of the planar groove 31. A notch 33 is provided on the side of the cylinder 32. The temperature sensor 13 is provided inside the cylinder 32, and the lead of the temperature sensor 13 is led out from the notch 33. The chip stage 2 described above can be used to heat the microfluidic chip 18.

[0056] Furthermore, the heating film 14 adopts a flexible structure, with a through hole in the center of the heating film 14 passing through the cylinder 32, and a wire through hole in the center of the heating block mounting plate 15, through which the wires of the heating film 14 and the temperature sensor 13 can be led out. This arrangement facilitates heating control of the chip stage 2 via the heating film 14. Moreover, the temperature sensor 13 can provide timely feedback on the temperature of the chip stage 2, thereby facilitating precise control of the subsequent heating temperature.

[0057] Furthermore, the heating block mounting plate 15 is provided with four through holes, corresponding to the four channels of the microfluidic chip 18. The ends of the through holes are threaded, and a tapered connector 16 is installed through the threaded connection. A thin steel cylinder 17 is installed inside the tapered connector 16, with its top end extending slightly beyond the heating block 12. A flared mouth 11 is fitted onto the top end of the thin steel cylinder 17. To ensure a tight contact between the outlet of the microfluidic chip and the flared mouth 11, the heights of the four flared mouths 11 must be at the same horizontal level. The position of the thin steel cylinder can be controlled by adjusting the depth of the tapered connector 16 screwed into the thread at the end of the through hole, thereby controlling the height of the flared mouth.

[0058] Furthermore, the heating block 12 has through holes that match the heating block mounting plate 15, and the heating film 14 has four notches that match the through holes on the heating block 12. The heating film 14 is tightly attached to the lower end of the heating block 12 with adhesive. A through hole is provided in the middle of the heating film 14 and the middle of the heating block mounting plate 15. The temperature sensor 13 is fixed to the middle through hole of the heating film 14 with adhesive. The wires of the temperature sensor 13 and the heating film 14 are led out from the through hole of the heating block mounting plate 15. The heating block 12 is fixed to the heating block mounting plate 15 with screws. When controlling the temperature of the chip, because the heating film 14 and the temperature sensor 13 are in close contact with the heating block 12, and the heating block 12 is in close contact with the chip, the chip heats up quickly and the temperature control is accurate.

[0059] Furthermore, the sample loading groove 4 is provided with four sample loading holes. The sample loading groove 4 is fixed to the microfluidic chip 18 with adhesive. The four sample loading holes are respectively aligned with the four inlets 19 of the microfluidic chip 18. The outlet 20 of the microfluidic chip 18 is connected to the horn 11. The fixture cover 1 is machined with a sample loading groove notch 34 for inserting the sample loading groove 4. O-rings are provided around the four sample loading holes. A rubber ring groove is provided at the top of the lower part of the sample loading groove 4. A rubber ring is installed on the rubber ring groove. After the microfluidic chip 18 is loaded, the rubber ring contacts the chip cover 7 to play a buffering role. The sample loading groove 4 is fixed to the microfluidic chip 18 with waterproof sealing double-sided tape. The O-ring at the lower end of the sample loading groove 4 plays a role in strengthening the seal.

[0060] Furthermore, the sample loading slot is located at the inlet of the microfluidic chip, and the chip cover 7 has a sample loading slot notch 34 for fixing the sample loading slot. When placing the chip, the sample loading slot of the chip should face upward and be aligned with the sample loading slot notch 34 of the chip cover 7. Only by using this correct method can the chip be inserted into the chip cover 7. The design of the sample loading slot and the chip cover 7 realizes the foolproof function.

[0061] Furthermore, after the microfluidic chip 18 is loaded, its four outlets form a passageway tightly against the flare opening. The pressure from the spring clips on the chip cover ensures a tighter connection between the chip outlets and the flare opening, resulting in a good seal and preventing air leakage. The heating film tightly attached inside the heating block enables rapid heating of the chip, while the small fan on the fixture base accelerates the cooling process. A temperature sensor inside the heating block provides feedback on the chip's current temperature for temperature control.

[0062] The working process and principle of this invention:

[0063] The microfluidic chip loading slot 4 not only stores reagents but also serves as a foolproof mechanism, making the loading of the microfluidic chip 18 more convenient and user-friendly. After the microfluidic chip 18 is loaded, the fixture cover 1 is closed, and the pressure head 10 is used to lock it in place, the four channels on the microfluidic chip align perfectly with the flared opening 11 on the chip stage 2 due to the limiting effect of the chip cover 7. The downward force provided by the spring plate 6 ensures the chip adheres tightly to the chip stage 2, resulting in more uniform heating, a tighter connection with the flared opening 11, and better sealing. The heating film 14 inside the chip stage 2 heats the chip, and the temperature sensor 13 inside the chip stage 2 monitors the chip temperature in real time. Both the heating film 14 and the temperature sensor 13 are controlled by a separate control system, enabling precise temperature control of the microfluidic chip. The small fan 9 located at the left end of the fixture accelerates airflow near the chip, shortening the cooling time.

[0064] Example 2:

[0065] A method for using a microfluidic chip temperature control fixture includes the following steps:

[0066] Step 1: Raise the fixture cover 1 at a certain angle. Then, insert the microfluidic chip 18 along the clamping groove between the chip base 8 and the chip cover 7. The microfluidic chip 18 touches the arc-shaped edge of the spring 6. Continue to push it to the left. The spring 6 undergoes elastic deformation under the action of force and generates a downward elastic force on the microfluidic chip 18, so that the microfluidic chip 18 is in close contact with the chip base 8. Continue to push it to the left. The microfluidic chip 18 will reach the leftmost end of the chip base 8.

[0067] Step 2: Insert the sample loading slot 4 into the fixture cover 1, ensuring that the sample loading hole of the sample loading slot 4 is located at the inlet of the microfluidic chip 18. At the same time, press the microfluidic chip 18 to ensure a sealed fit. At this time, due to the limiting effect of the chip clamping slot of the fixture cover 1 and the sample loading slot notch 34 of the chip cover 7, the sample loading slot 4 fixed on the microfluidic chip 18 is exactly located in the sample loading slot notch of the chip cover 7. The chip is in the optimal position and can only move up and down, but cannot move around.

[0068] Step 3: Close the clamp cover 1. The microfluidic chip 18 will contact the chip stage 2. Continue to close the clamp cover 1. The chip stage 2 will exert an upward force on the microfluidic chip 18. The spring 6 on the chip cover 7 is compressed under this force and makes the microfluidic chip 18 come into close contact with the heating block 12 on the chip stage 2. The horn 11 on the chip stage 2 is connected to the outlet of the microfluidic chip 18 to form a passage. At this time, the clamp cover 1 is locked with the pressure head 10, and the chip loading is completed.

[0069] Step 4: Connect the other end of the thin steel cylinder 17 to the negative pressure pump. In this way, the entire system pathway is formed. The negative pressure pump can generate negative pressure at the outlet of the microfluidic chip 18, add body fluid samples through the sample loading tank 4, and then enter the microfluidic chip 18 through the inlet of the microfluidic chip 18.

[0070] Step 5: When it is necessary to control the temperature of the microfluidic chip 18, the microfluidic chip 18 is heated by the heating film 14 inside the chip stage 2. The temperature sensor 13 inside the chip stage 2 detects the temperature of the microfluidic chip 18 in real time. The heating film 14 and the temperature sensor 13 are connected to the temperature control system, thereby achieving precise temperature control of the microfluidic chip 18. The small fan 9 located on one side of the fixture can accelerate the airflow near the microfluidic chip 18, shortening the cooling time.

Claims

1. A microfluidic chip temperature control fixture, characterized by: The fixture includes a fixture base (3) for mounting the entire fixture; a clamping groove is provided in the middle of the fixture base (3), and a chip stage (2) is carried inside the clamping groove; a heating film (14) and a temperature sensor (13) for precise temperature control of the microfluidic chip (18) are provided inside the chip stage (2); a fixture cover (1) for mounting the microfluidic chip (18) is hinged to one side of the fixture base (3) via a connecting shaft, and the fixture cover (1) can rotate around the connecting shaft and press the chip. The chip carrier (2) has a pressure head (10) hinged to the other side of the clamp base (3) for pressing and locking the upper cover (1) of the clamp; a small fan (9) for cooling is fixed on the clamp base (3) and close to the inner wall of the second protrusion; the chip carrier (2) includes a heating block mounting plate (15), a heating block (12), a heating film (14), a temperature sensor (13), a flared mouth (11), a thin steel cylinder (17) and an inverted conical joint (16); the heating block mounting plate (15) is set at the bottom of the clamp. In the middle part of the seat (3), a heating block (12) is fixedly installed on the top of the heating block mounting plate (15). A flat groove is provided at the bottom end of the heating block (12). The heating film (14) is fixed in the flat groove (31) by adhesive. A cylinder (32) is provided in the middle part of the flat groove (31). A notch (33) is provided on the side of the cylinder (32). A temperature sensor (13) is provided inside the cylinder (32). The lead wire of the temperature sensor (13) is led out from the notch (33); the heating film (14) The heating block mounting plate (15) has a through hole in the middle of the cylinder (32) and a wire hole in the middle of the heating block mounting plate (15). The heating block mounting plate (15) has four through holes, which correspond to the four channels of the microfluidic chip (18). The end of the through hole is threaded and a tapered connector (16) is installed through the thread. A thin steel cylinder (17) is installed inside the tapered connector (16). The top of the thin steel cylinder (17) extends out of the heating block (12) by a small section, and the flared mouth (11) is fitted on the top of the thin steel cylinder (17).

2. The temperature-controlled microfluidic chip holder of claim 1, wherein: The clamp base (3) has multiple sets of through holes (29) symmetrically machined on both sides. The through holes (29) are used to pass through bolts and fix the entire clamp base (3) on the instrument base (30). A first boss (25) is provided on one side of the top of the clamp base (3). The pressure head (10) is hinged on the first boss (25) by a round pin (35). A second boss (26) is provided on the other side of the top of the clamp base (3). An arc-shaped groove (27) is provided in the middle part of the second boss (26). The clamp cover (1) is hinged on the second boss (26) by a connecting shaft (28).

3. The temperature-controlled microfluidic chip holder of claim 2, wherein: The fixture cover (1) includes a chip base (8), a chip cover (7), a spring (6), a spring pressure plate (5), and a sample loading slot (4); one end of the chip base (8) is hinged to the fixture base (3), and the chip base (8) and the chip cover (7) are fixed by bolts. A chip loading slot is formed between the chip base (8) and the chip cover (7), and the microfluidic chip (18) can be inserted into the chip loading slot and can move up and down.

4. The temperature-controlled microfluidic chip holder of claim 3, wherein: The chip cover (7) is machined with a strip-shaped through groove. A spring (6) for pressing the microfluidic chip (18) is placed in the strip-shaped through groove. The spring (6) is pressed and fixed by a spring plate (5). The spring plate (5) is fixed to the top of the chip cover (7) by bolts and is located at the position of the strip-shaped through groove.

5. The microfluidic chip temperature control fixture according to claim 3, characterized in that: A protruding block (21) is provided on the top of the chip base (8) and at the end where the pressure head (10) is located. A circular hole (23) is provided on the top of the protruding block (21) for cooperating with the spring needle (22) installed on the pressure head (10). A beveled notch (24) is provided on the edge of the protruding block (21) to facilitate the passage of the spring needle (22).

6. The microfluidic chip temperature control fixture according to claim 3, characterized in that: The heating film (14) has a flexible structure, and the wires of the heating film (14) and the temperature sensor (13) can be led out through this wire hole.

7. The microfluidic chip temperature control fixture according to claim 3, characterized in that: The sample loading slot (4) is provided with four sample loading holes. The sample loading slot (4) is fixed to the microfluidic chip (18) by adhesive. The four sample loading holes are respectively aligned with the four inlets (19) of the microfluidic chip (18). The outlet (20) of the microfluidic chip (18) is connected to the horn (11). The fixture cover (1) is machined with a sample loading slot notch (34) for inserting the sample loading slot (4). O-rings are provided around the four sample loading holes. A rubber ring groove is provided at the top of the lower part of the sample loading slot (4). A rubber ring is installed on the rubber ring groove. When the microfluidic chip (18) is loaded, the rubber ring contacts the chip cover (7) to play a buffering role. The sample loading slot (4) is fixed to the microfluidic chip (18) by waterproof sealing double-sided tape. The O-ring at the lower end of the sample loading slot (4) plays a role in strengthening the seal.

8. A method of using the microfluidic chip temperature control fixture according to any one of claims 4-7, characterized in that, Includes the following steps: Step 1: Raise the clamp cover (1) at a certain angle, and then insert the microfluidic chip (18) into the space between the chip base (8) and the chip cover (7) along the clamping groove. The microfluidic chip (18) touches the arc edge of the spring (6) and continues to be pushed to the left. The spring (6) undergoes elastic deformation under the action of force and generates a downward elastic force on the microfluidic chip (18), so that the microfluidic chip (18) is in close contact with the chip base (8). Continue to push to the left, and the microfluidic chip (18) will reach the leftmost end of the chip base (8). Step 2: Insert the sample loading slot (4) into the fixture cover (1) and ensure that the sample loading hole of the sample loading slot (4) is located at the inlet of the microfluidic chip (18). At the same time, press the microfluidic chip (18) to ensure a sealed fit. At this time, due to the limiting effect of the chip clamping slot of the fixture cover (1) and the sample loading slot notch (34) of the chip cover (7), the sample loading slot (4) fixed on the microfluidic chip (18) is located in the sample loading slot notch of the chip cover (7). The chip is in the optimal position and can only move up and down, not around. Step 3: Close the fixture cover (1). The microfluidic chip (18) will contact the chip stage (2). Continue to close the fixture cover (1). The chip stage (2) will exert an upward force on the microfluidic chip (18). The spring (6) on the chip cover (7) is compressed under this force and makes the microfluidic chip (18) and the heating block (12) on the chip stage (2) come into close contact. The horn (11) on the chip stage (2) is connected to the outlet of the microfluidic chip (18) to form a passage. At this time, use the pressure head (10) to lock the fixture cover (1). The chip loading is completed. Step 4: Connect the other end of the thin steel cylinder (17) to the negative pressure pump. In this way, the entire system pathway is formed. The negative pressure pump can generate negative pressure at the outlet of the microfluidic chip (18). The body fluid sample is added through the sample loading tank (4) and then enters the microfluidic chip (18) through the inlet. Step 5: When it is necessary to control the temperature of the microfluidic chip (18), the microfluidic chip (18) is heated by the heating film (14) inside the chip stage (2). The temperature sensor (13) inside the chip stage (2) detects the temperature of the microfluidic chip (18) in real time. The heating film (14) and the temperature sensor (13) are connected to the temperature control system, thereby achieving precise temperature control of the microfluidic chip (18). The small fan (9) located on one side of the fixture can accelerate the air flow near the microfluidic chip (18) and shorten the cooling time.

Images