A nanometer volume flow generating device and method based on temperature control regulation principle

Abstract

This invention discloses a nano-volume flow rate generation device and method based on temperature control principle, comprising an outer water bath, an inner water bath, a liquid storage container, a capillary tube, a microscopic vision acquisition module, and a controller. The inner water bath is disposed inside the outer water bath. A first thermistor heater and a second thermistor heater are respectively installed in the outer and inner water baths. The liquid storage container is installed on the bottom wall of the inner water bath. The capillary tube is connected to the top of the liquid storage container. A gallium indium tin alloy is disposed inside the liquid storage container. A temperature measuring component is disposed inside the inner water bath. An observation window is provided on the side wall of the inner water bath. This invention significantly reduces the influence of heat diffusion and environmental interference through layered gradient temperature control, multi-point distributed temperature measurement, and automatic visual detection, achieving stable nano-flow output with reliable traceability and low uncertainty. Furthermore, the use of gallium indium tin alloy as the expansion driving medium improves the safety of the device.

Description

Technical Field

[0001] This invention relates to the field of micro-liquid flow metering and detection technology, and more specifically to a nano-volume flow generation device and method based on the principle of temperature control. Background Technology

[0002] Microfluidics and nanofluidics technologies are now widely used in life sciences, the automotive industry, medical devices, and micro / nanofabrication. In particular, applications such as medical pain control pumps, dermal implantable drug delivery devices, single-cell analysis, and micro-reagent dispensing place extremely high demands on the accuracy, stability, and traceability of nanofluid flow rates. While traditional nanofluidics devices based on the principle of mercury thermal expansion possess traceability potential, they also present challenges such as high toxicity, volatility, and complex hazardous waste disposal. Summary of the Invention

[0003] In view of this, the present invention provides a nano-volume flow generation device and method based on the principle of temperature control, the purpose of which is to solve the problems existing in the prior art.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A nano-volume flow rate generation device based on temperature control principle includes: an outer water bath, an inner water bath, a liquid storage container, a capillary tube, a microscopic vision acquisition module, and a controller; the inner water bath is disposed inside the outer water bath; a first thermistor heater and a second thermistor heater are respectively provided in the outer water bath and the inner water bath; the liquid storage container is installed on the bottom wall of the inner water bath via a first fixing mechanism; the capillary tube is detachably connected to the top of the liquid storage container via a quick-connect fitting assembly; a first liquid inlet is provided at the top of the capillary tube; a gallium indium tin alloy is disposed inside the liquid storage container as an expansion driving medium; a negative pressure vacuum port and a second liquid inlet are provided at the top of the liquid storage container; a temperature measuring component is disposed inside the inner water bath for real-time acquisition of temperature gradient data in the inner water bath; an observation window corresponding to the capillary tube is embedded on the side wall of the inner water bath; the microscopic vision acquisition module is disposed corresponding to the observation window.

[0005] Preferably, the first fixing mechanism includes a first fixing seat and a clamping assembly; the bottom of the first fixing seat is provided with a first buffer pad; a first groove adapted to the first buffer pad is formed on the bottom wall of the inner water bath tank; the lower part of the first buffer pad is inserted into the first groove; the top of the first fixing seat is provided with a multi-level stepped groove for adapting to liquid storage containers of different specifications; the clamping assembly is disposed on the top of the first fixing seat for clamping and fixing the liquid storage container.

[0006] Preferably, the clamping assembly includes a fixing ring; the fixing ring is sleeved on the outside of the liquid storage container; a plurality of support rods are evenly distributed at the bottom of the fixing ring; the bottom of the support rods is fixedly connected to the top of the first fixing seat; a plurality of threaded rods are threadedly connected to the side wall of the fixing ring; the end of the threaded rod near the liquid storage container extends into the interior of the fixing ring and is rotatably connected to a clamping plate; a guide rod is provided on the side of the clamping plate away from the liquid storage container; the guide rod passes through the fixing ring; the guide rod is slidably connected to the fixing ring.

[0007] Preferably, the temperature measuring component includes a plurality of first temperature sensors and a plurality of second temperature sensors; the number of first temperature sensors is the same as that of the clamping plates, and they are arranged in a one-to-one correspondence; the clamping plates have a mounting groove extending through both sides of the clamping plates on the side near the liquid storage container; the first temperature sensors are disposed in the mounting groove; and the plurality of second temperature sensors are arranged along the axial direction of the capillary.

[0008] Preferably, the clamping plate is provided with a second buffer pad on the side near the liquid storage container.

[0009] Preferably, both the first thermistor heater and the second thermistor heater are annular structures.

[0010] Preferably, the microscopic visual acquisition module includes a light source unit and a microscopic imaging unit; the light source unit is disposed inside the inner water bath and is used to irradiate the capillary; the microscopic imaging unit is disposed outside the outer water bath and corresponds to the observation window.

[0011] Preferably, the light source unit includes an annular mounting plate and an LED lamp; an annular fixing plate is provided on the inner side wall of the inner water bath tank; an annular groove adapted to the annular mounting plate is opened on the top of the annular fixing plate; the annular mounting plate is installed in the annular groove; and the LED lamp is inclinedly arranged on the inner side of the annular mounting plate.

[0012] A method for generating nano-volume flow rate based on the principle of temperature control, utilizing the aforementioned nano-volume flow rate generating device based on the principle of temperature control, includes the following steps: S1, the capillary tube is installed on the top of the liquid storage container through the quick-connect assembly, and the liquid storage container and the capillary tube are vacuumed through the negative pressure vacuum interface; S2, Gallium indium tin alloy is injected into the liquid storage container through the second liquid inlet, and the total mass of the liquid storage container before and after the Gallium indium tin alloy is injected is weighed by an electronic balance to determine the net mass of the Gallium indium tin alloy. Then, the fluid to be tested is injected into the capillary through the second liquid inlet. S3, place the liquid storage container and the capillary tube into the inner water bath, and add a temperature control medium into the outer water bath and the inner water bath; S4, the controller controls the first thermistor heater and the second thermistor heater to start, the first thermistor heater and the second thermistor heater control the outer water bath and the inner water bath to generate a constant temperature gradient, and the temperature data is detected and corrected in real time by the temperature measuring component; S5, the temperature in the inner water bath rises continuously and uniformly, and the gallium indium tin alloy expands in volume due to heating, pushing the fluid to be measured to form a nanoflow; during this process, the microscopic vision acquisition module acquires the liquid level image of the gallium indium tin alloy in the capillary, the controller calculates the liquid level change per unit time, and calculates the real-time volumetric flow rate by combining the density of gallium indium tin alloy and the coefficient of thermal expansion.

[0013] Preferably, the flow rate is calculated using the following formula:

[0014] in, The volume is a function of temperature T, and m is the mass of the gallium indium tin alloy. It is density; Reference temperature Reference density of gallium indium tin alloy, A It is the linear volume expansion coefficient of gallium indium tin alloy. B It is the coefficient of secondary volume expansion of gallium indium tin alloy; for Instantaneous flow rate.

[0015] Compared with the prior art, the present invention has achieved the following technical effects: The present invention uses a combination of components such as a thermistor heater, a temperature measuring component, a microscopic vision acquisition module, and a controller to achieve layered gradient temperature control, multi-point distributed temperature measurement, and automatic visual inspection, which greatly reduces the impact of heat diffusion and environmental interference, achieves stable nanocurrent output, and has reliable traceability and low uncertainty. At the same time, it uses gallium indium tin alloy as the expansion driving medium to achieve mercury-free, non-toxic, and non-volatile processes, thereby improving the safety of the device. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a nano-volume flow rate generation device based on the principle of temperature control according to the present invention. Figure 2 for Figure 1 A magnified view of part A in the middle; Figure 3 for Figure 1A magnified view of part B in the middle section; Figure 4 A schematic diagram of the gallium indium tin alloy inside the liquid storage container and capillary tube, and the fluid to be tested. In the diagram: 1. Outer water bath; 2. Inner water bath; 3. Liquid storage container; 4. Capillary tube; 5. First thermistor heater; 6. Second thermistor heater; 7. First liquid inlet port; 8. Gallium indium tin alloy; 9. Vacuum port; 10. Second liquid inlet port; 11. Observation window; 12. First fixing base; 13. First buffer pad; 14. Multi-stage stepped groove; 15. Fixing ring; 16. Support rod; 17. Threaded rod; 18. Clamp 19. Plate; 20. Guide rod; 21. First temperature sensor; 22. Second temperature sensor; 23. Mounting groove; 24. Second buffer pad; 25. Microscopic imaging unit; 26. Annular mounting plate; 27. LED light; 28. Fluid to be tested; 29. ​​Sealing and heat insulation cover; 30. Connecting rod; 31. Vertical plate; 32. Electric push rod; 33. Observation seat; 34. Quick-connect connector body; 35. Quick-connect fixing seat; 36. Locking sleeve; 37. Annular fixing plate. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example

[0019] Reference Figure 1-4As shown, this invention discloses a nano-volume flow rate generation device based on the principle of temperature control, comprising: an outer water bath 1, an inner water bath 2, a liquid storage container 3, a capillary tube 4, a microscopic vision acquisition module, and a controller; the inner water bath 2 is disposed inside the outer water bath 1, forming a double-stage heat insulation and temperature control structure; a first thermistor heater 5 and a second thermistor heater 6 are respectively provided in the outer water bath 1 and the inner water bath 2; the liquid storage container 3 is installed on the inner bottom wall of the inner water bath 2 through a first fixing mechanism; the capillary tube 4 is detachably connected to the top of the liquid storage container 3 through a quick-connect fitting assembly; the top of the capillary tube 4 is provided with... The first liquid inlet port 7; the liquid storage container 3 is equipped with a gallium indium tin alloy 8 inside, which is used as an expansion driving medium; the top of the liquid storage container 3 is equipped with a negative pressure vacuum port 9 and a second liquid inlet port 10; the inner water bath 2 is equipped with a temperature measuring component, which is used to collect temperature gradient data in the inner water bath in real time; the side wall of the inner water bath 2 is embedded with an observation window 11 corresponding to the capillary tube 4; the microscopic vision acquisition module is set in correspondence with the observation window 11; the microscopic vision acquisition module, the first thermistor heater, the second thermistor heater 6 and the temperature measuring component are all electrically connected to the controller to realize closed-loop control of temperature and flow and data storage.

[0020] In this embodiment, the first fixing mechanism includes a first fixing seat 12 and a clamping assembly; the bottom of the first fixing seat 12 is provided with a first buffer pad 13 to reduce the impact of external vibration on the liquid storage container 3; a first groove adapted to the first buffer pad 13 is opened on the inner bottom wall of the inner water bath 2; the lower part of the first buffer pad 13 is inserted into the first groove; a multi-level stepped groove 14 is opened on the top of the first fixing seat 12 to adapt to liquid storage containers 3 of different specifications; the clamping assembly is set on the top of the first fixing seat 12 to clamp and fix the liquid storage container 3.

[0021] In this embodiment, the clamping assembly includes a fixing ring 15; the fixing ring 15 is sleeved on the outside of the liquid storage container 3; a plurality of support rods 16 are evenly distributed at the bottom of the fixing ring 15; the bottom of the support rods 16 is fixedly connected to the top of the first fixing seat 12; a plurality of threaded rods 17 are threadedly connected to the side wall of the fixing ring 15; one end of the threaded rod 17 near the liquid storage container 3 extends into the interior of the fixing ring 15 and is rotatably connected to a clamping plate 18; a guide rod 19 is provided on the side of the clamping plate 18 away from the liquid storage container 3; the guide rod 19 passes through the fixing ring 15; the guide rod 19 is slidably connected to the fixing ring 15; in use, by rotating the threaded rod 17, the clamping plate 18 is driven to approach the liquid storage container 3, thereby clamping and fixing the liquid storage container 3.

[0022] In this embodiment, the temperature measuring component includes multiple first temperature sensors 20 and multiple second temperature sensors 21; the number of first temperature sensors 20 is the same as that of the clamping plate 18, and they are arranged in a one-to-one correspondence; the clamping plate 18 has a mounting groove 22 that runs through both sides of the clamping plate 18 on the side near the liquid storage container 3; the first temperature sensors 20 are disposed in the mounting groove 22; the multiple second temperature sensors 21 are arranged along the axial direction of the capillary tube 4.

[0023] In this embodiment, there are six first temperature sensors 20; correspondingly, there are also six clamping plates 18 and six threaded rods 17; the six threaded rods 17 are arranged in a ring array on the side wall of the fixing ring 15; there are four second temperature sensors 21; two second temperature sensors 21 are located at the upper part of the capillary tube 4, and the other two second temperature sensors 21 are located at the lower part of the capillary tube 4.

[0024] In this embodiment, the outer water bath 1 and the inner water bath 2 are provided with a sealed heat insulation cover 28 on top.

[0025] In this embodiment, two second temperature sensors 21 located at the upper part of the capillary tube 4 are connected to the bottom of the sealed heat insulation cover 28 via connecting rods 29; two second temperature sensors 21 located at the lower part of the capillary tube 4 have a vertical plate 30 at the end away from the capillary tube 4; the vertical plate 30 is connected to the inner wall of the inner water bath 2 via an electric push rod 31, which facilitates adjusting the distance between the second temperature sensors 21 and the capillary tube 4, thereby facilitating the removal and placement of the liquid storage container.

[0026] In this embodiment, a second buffer pad 23 is provided on the side of the clamping plate 18 near the liquid storage container 3.

[0027] In this embodiment, both the first thermistor heater 5 and the second thermistor heater 6 are annular structures.

[0028] In this embodiment, the microscopic vision acquisition module includes a light source unit and a microscopic imaging unit 24; the light source unit is located inside the inner water bath 2 and is used to irradiate the capillary 4; the microscopic imaging unit 24 is located outside the outer water bath 1 and corresponds to the observation window 11.

[0029] In this embodiment, the light source unit includes an annular mounting plate 25 and an LED lamp 26; an annular fixing plate 36 is provided on the inner side wall of the inner water bath tank 2; an annular groove adapted to the annular mounting plate 25 is opened on the top of the annular fixing plate 36; the annular mounting plate 25 is installed in the annular groove; the LED lamp 26 is obliquely arranged on the inner side of the annular mounting plate 25, so that the LED lamp 26 obliquely illuminates the capillary tube 4, which is used to weaken the reflection of liquid metal and highlight the meniscus contour.

[0030] In this embodiment, the microscopic imaging unit 24 includes a microscope and an industrial camera; the microscope is connected to the industrial camera via a CTV adapter ring.

[0031] In this embodiment, a third temperature sensor is provided inside the outer water bath 1.

[0032] In this embodiment, the first temperature sensor 20, the second temperature sensor 21, and the third temperature sensor are all NTC temperature sensors with a resolution of 1 mK.

[0033] In this embodiment, a sealing control valve is provided on the first liquid inlet port 7, the negative pressure vacuum port 9, and the second liquid inlet port 10.

[0034] In this embodiment, a second fixing seat is provided inside the outer water bath 1; multiple columns are evenly distributed at the bottom of the second fixing seat; the columns are fixedly connected to the inner bottom wall of the outer water bath 1; a placement groove is provided at the top of the second fixing seat; a second buffer pad is provided inside the placement groove; and a through groove is provided at the center of the bottom of the placement groove.

[0035] In this embodiment, an observation seat 32 corresponding to the observation window 11 is embedded on the outer wall of the outer water bath 1; the side of the observation seat 32 near the inner water bath 2 is sealed and fitted to the outer wall of the inner water bath 2; an observation groove is opened inside the observation seat 32, penetrating both sides of the observation seat 32.

[0036] In this embodiment, the flow generation process is based on the thermodynamic expansion control of the driving liquid medium, while traceability is based on volume transfer and mass conservation.

[0037] In this embodiment, the quick-connect assembly includes a quick-connect body 33; the quick-connect body 33 is fixedly sleeved on the outer side wall of the bottom of the capillary tube 4; a locking sleeve 35 is movably sleeved on the outer side of the quick-connect body 33; a quick-connect fixing seat 34 is provided on the top of the liquid storage container; a slot is opened on the top of the quick-connect fixing seat 34; the quick-connect body 33 is inserted into the slot; the locking sleeve 35 is threadedly connected to the outer side wall of the quick-connect fixing seat 34; in use, the lower part of the quick-connect body 33 is inserted into the slot, and the locking sleeve 35 is rotated downwards so that the locking sleeve 35 is threadedly connected to the outer side wall of the quick-connect fixing seat 34, thus fixing the quick-connect body 33 and the quick-connect fixing seat 34 together, thereby realizing the quick installation of the capillary tube 4 and the liquid storage container 3.

[0038] In other embodiments, the entire device is housed in a temperature-controlled laboratory or temperature-controlled experimental chamber to further reduce heat leakage.

[0039] In some other embodiments, the vertical plate 30 is provided with an inner sleeve on the side away from the capillary tube 4; an outer sleeve is provided on the inner wall of the inner water bath 2; both the outer sleeve and the inner sleeve are sleeved on the outside of the electric push rod 31; the end of the inner sleeve away from the vertical plate 30 is slidably connected to the inner sleeve.

[0040] This invention also discloses a nano-volume flow rate generation method based on the principle of temperature control, which utilizes the aforementioned nano-volume flow rate generation device based on the principle of temperature control and includes the following steps: S1, the capillary tube 4 is installed on the top of the liquid storage container 3 through the quick-connect fitting assembly, and the liquid storage container 3 and the capillary tube 4 are vacuumed through the negative pressure vacuum port 9. S2, Gallium indium tin alloy 8 is injected into the storage container 3 through the second liquid inlet, and the total mass of the storage container 3 before and after the Gallium indium tin alloy 8 is injected is weighed by an electronic balance to determine the net mass of the Gallium indium tin alloy 8. Then, the fluid to be tested 27 is injected into the capillary tube 4 through the second liquid inlet. S3, place the liquid storage container 3 and capillary tube 4 into the inner water bath 2, and add temperature control medium to the outer water bath 1 and the inner water bath 2; S4, the controller controls the first thermistor heater 5 and the second thermistor heater 6 to start, the first thermistor heater 5 and the second thermistor heater 6 control the outer water bath 1 and the inner water bath 2 to generate a constant temperature gradient, and the temperature data is detected and corrected in real time by the temperature measuring component. S5, the temperature in the inner water bath 2 continues to rise uniformly, and the gallium indium tin alloy 8 expands in volume due to heating, pushing the fluid to be measured 27 to form a nanoflow; during this process, the microscopic vision acquisition module acquires the liquid level image of the gallium indium tin alloy 8 in the capillary 4, and the controller calculates the liquid level change per unit time through the image analysis module, and calculates the real-time volumetric flow rate by combining the density and thermal expansion coefficient of the gallium indium tin alloy 8.

[0041] In S5, the controller compares the real-time flow rate with the target flow rate and dynamically fine-tunes the temperature gradient and heating rate in the inner water bath 2 to achieve adaptive flow correction.

[0042] In this embodiment, the flow rate is calculated using the following formula:

[0043] in, The volume is a function of temperature T, and m is the mass of the gallium indium tin alloy. It is density; Reference temperature Reference density of gallium indium tin alloy, A It is the linear volume expansion coefficient of gallium indium tin alloy. B It is the coefficient of secondary volume expansion of gallium indium tin alloy; for Instantaneous flow rate.

[0044] In this embodiment, the flow rate adjustment is divided into two modes: Mode 1 is the medium quality adjustment mode, which changes the filling quality of the gallium indium tin alloy by replacing the liquid storage container 3 and capillary tube 4 of different specifications, and adapts to a large range of flow rates; Mode 2 is the temperature gradient adjustment mode, which dynamically adjusts the heating slope of the inner water bath 2 under the same set of liquid storage container 3 and capillary tube 4, so as to achieve precise fine-tuning of the flow rate in a small range.

[0045] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A nano-volume flow rate generation device based on the principle of temperature control, characterized in that, include: The system comprises an outer water bath (1), an inner water bath (2), a liquid storage container (3), a capillary tube (4), a microscopic vision acquisition module, and a controller; the inner water bath (2) is located inside the outer water bath (1); the outer water bath (1) and the inner water bath (2) are respectively equipped with a first thermistor heater (5) and a second thermistor heater (6); the liquid storage container (3) is installed on the bottom wall of the inner water bath (2) by a first fixing mechanism; the capillary tube (4) is detachably connected to the top of the liquid storage container (3) by a quick-connect fitting assembly. The capillary tube (4) is provided with a first liquid inlet (7) at the top; the liquid storage container (3) is provided with a gallium indium tin alloy (8) inside, which is used as an expansion driving medium; the liquid storage container (3) is provided with a negative pressure vacuum port (9) and a second liquid inlet (10) at the top; the inner water bath (2) is provided with a temperature measuring component, which is used to collect temperature gradient data in the inner water bath in real time; the inner water bath (2) is provided with an observation window (11) corresponding to the capillary tube (4) on the side wall; the microscopic vision acquisition module is set in correspondence with the observation window (11).

2. The nano-volume flow rate generating device based on the temperature control principle according to claim 1, characterized in that, The first fixing mechanism includes a first fixing seat (12) and a clamping assembly; the bottom of the first fixing seat (12) is provided with a first buffer pad (13); the inner bottom wall of the inner water bath (2) is provided with a first groove that is adapted to the first buffer pad (13); the lower part of the first buffer pad (13) is inserted into the first groove; the top of the first fixing seat (12) is provided with a multi-level stepped groove (14) for adapting to different specifications of the liquid storage container (3); the clamping assembly is provided on the top of the first fixing seat (12) for clamping and fixing the liquid storage container (3).

3. The nano-volume flow rate generating device based on the temperature control principle according to claim 2, characterized in that, The clamping assembly includes a fixing ring (15); the fixing ring (15) is sleeved on the outside of the liquid storage container (3); a plurality of support rods (16) are evenly distributed at the bottom of the fixing ring (15); the bottom of the support rods (16) is fixedly connected to the top of the first fixing seat (12); a plurality of threaded rods (17) are threadedly connected to the side wall of the fixing ring (15); the threaded rods (17) extend into the fixing ring (15) at one end near the liquid storage container (3) and are rotatably connected to a clamping plate (18); a guide rod (19) is provided on the side of the clamping plate (18) away from the liquid storage container (3); the guide rod (19) passes through the fixing ring (15); the guide rod (19) is slidably connected to the fixing ring (15).

4. The nano-volume flow rate generating device based on the temperature control principle according to claim 3, characterized in that, The temperature measuring component includes multiple first temperature sensors (20) and multiple second temperature sensors (21); the number of first temperature sensors (20) is the same as that of the clamping plate (18), and they are arranged in a one-to-one correspondence; the clamping plate (18) has an installation groove (22) that runs through both sides of the clamping plate (18) on the side near the liquid storage container (3); the first temperature sensors (20) are disposed in the installation groove (22); the multiple second temperature sensors (21) are arranged along the axial direction of the capillary tube (4).

5. A nano-volume flow rate generating device based on temperature control principle according to claim 4, characterized in that, The clamp (18) is provided with a second buffer pad (23) on the side near the liquid storage container (3).

6. A nano-volume flow rate generating device based on temperature control principle according to claim 1, characterized in that, Both the first thermistor heater (5) and the second thermistor heater (6) are annular structures.

7. A nano-volume flow rate generating device based on temperature control principle according to claim 1, characterized in that, The microscopic visual acquisition module includes a light source unit and a microscopic imaging unit (24); the light source unit is located inside the inner water bath (2) and is used to irradiate the capillary (4); the microscopic imaging unit (24) is located outside the outer water bath (1) and corresponds to the observation window (11).

8. A nano-volume flow rate generating device based on temperature control principle according to claim 7, characterized in that, The light source unit includes an annular mounting plate (25) and an LED lamp (26); an annular fixing plate (36) is provided on the inner side wall of the inner water bath tank (2); an annular groove adapted to the annular mounting plate (25) is opened on the top of the annular fixing plate (36); the annular mounting plate (25) is installed in the annular groove; the LED lamp (26) is inclinedly arranged on the inner side of the annular mounting plate (25).

9. A method for generating nano-volume flow rate based on the principle of temperature control, characterized in that, The nano-volume flow rate generating device based on the temperature control principle as described in any one of claims 1-8 includes the following steps: S1, the capillary tube (4) is installed on the top of the liquid storage container (3) through the quick-connect fitting assembly, and the liquid storage container (3) and the capillary tube (4) are vacuumed through the negative pressure vacuum port (9); S2, inject gallium indium tin alloy (8) into the storage container (3) through the second liquid inlet, and weigh the total mass of the storage container (3) before and after injecting gallium indium tin alloy (8) through an electronic balance to determine the net mass of gallium indium tin alloy (8). Then inject the fluid to be tested (27) into the capillary (4) through the second liquid inlet. S3, place the liquid storage container (3) and the capillary tube (4) into the inner water bath (2), and add temperature control medium to the outer water bath (1) and the inner water bath (2); S4, the controller controls the first thermistor heater (5) and the second thermistor heater (6) to start, the first thermistor heater (5) and the second thermistor heater (6) control the outer water bath (1) and the inner water bath (2) to generate a constant temperature gradient, and the temperature data is detected and corrected in real time by the temperature measuring component; S5, the temperature in the inner water bath (2) continues to rise uniformly, and the gallium indium tin alloy (8) expands in volume due to heat, pushing the fluid to be tested (27) to form a nanoflow; during this process, the microscopic vision acquisition module acquires the liquid level image of the gallium indium tin alloy (8) in the capillary (4), the controller calculates the liquid level change per unit time, and calculates the real-time volume flow rate by combining the density and thermal expansion coefficient of the gallium indium tin alloy (8).

10. A method for generating nano-volume flow rate based on temperature control principle according to claim 9, characterized in that, The flow rate is calculated using the following formula: in, The volume is a function of temperature T, and m is the mass of the gallium indium tin alloy (8). It is density; Reference temperature Reference density of gallium indium tin alloy, A It is the linear volume expansion coefficient of gallium indium tin alloy. B It is the coefficient of secondary volume expansion of gallium indium tin alloy; for Instantaneous flow rate.

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