An artificial joint in-situ testing machine based on a variable curvature microfluidic fixture and its use method

Abstract

The present invention relates to the technical field of material mechanics testing equipment, and in particular to an artificial joint in-situ testing machine based on a variable curvature microfluidic fixture and a method for using the same, comprising a drive unit, a fixture test unit, and a mobile unit on a platform base, wherein the drive unit is located on one side of the platform base, the drive unit and the mobile unit are connected by a gear transmission assembly, the mobile unit is respectively connected to the fixture assembly and the test assembly of the fixture test unit via a slider assembly, the liquid pool of the fixture test unit is located in the center of the platform base, the fixture assembly is located inside the liquid pool, and a temperature control assembly is also provided inside the liquid pool. The present invention adopts the above structure, and a variable curvature microfluidic channel combining a semicircle and an arc is provided in the flexible gasket to achieve force anisotropy, the semicircular microfluidic channel avoids stress concentration, and the arc microfluidic channel realizes the interaction between the flow of the liquid medium and the sample observation area.

Description

Technical Field

[0001] The present invention relates to the technical field of material mechanics testing equipment, and in particular to an artificial joint in-situ testing machine based on a variable curvature micro-channel fixture and a use method thereof. Background Art

[0002] The in vivo service mechanical environment of artificial joints is complex, and the loads they are subjected to change dynamically in a cyclical and multi-directional manner. The joint cavity in which they are located contains synovial fluid with various biological components, which has a certain viscosity and cushioning property and continuously acts on the joint surface to affect the mechanical properties of the material. Given that the human body is in a "black box state", it is extremely difficult to conduct mechanical monitoring in vivo. In order to explore replacement materials with better performance, it is of practical significance to reproduce the actual service environment in vitro and conduct mechanical tests. Simulating the various mechanical loads that artificial joints are subjected to in actual service, such as pressure, friction, impact, etc., while taking into account the lubricating effect of synovial fluid on joint movement and the chemical effect on the joint surface, can more comprehensively evaluate the mechanical properties, wear characteristics, durability and other performance indicators of artificial joints in complex liquid environments.

[0003] In addition, exploring the deformation mechanism of the microstructure of materials under service conditions, such as grain deformation, dislocation movement, and grain boundary changes, is the key to revealing macroscopic deformation behavior and a direct way to obtain the mechanical properties of joint materials. In conventional mechanical experiments, the response of the microstructure is complex and rapid, and it is quite difficult to observe the evolution process in real time. After deformation, the material has "residual" traces of microstructural changes, such as dislocation distribution, density, and morphology. With the help of microanalysis methods such as scanning electron microscopy for characteristic analysis, researchers can reversely infer the evolution mode of the material microstructure during the stress process and reveal the behavior laws of the microstructure in the mechanical process. However, the characterization of the cross-sectional microstructure in the above-mentioned test method is observed for a specific state and time. The results obtained are not for the entire test period. They reflect the microstructural characteristics of a certain area under a specific state in the micro-area material test, and discontinuously show the performance of the local microstructure. The dynamic evaluation of the material performance lacks continuous characterization information, such as the dynamic evolution process of dislocations.

[0004] In-situ experiments combining mechanical testing with scanning electron microscopy (SEM) can explore the relationship between microstructure and mechanical properties. High-resolution electron microscopy can be used to observe the deformation process of grains and the trajectory of dislocation motion, obtaining images of the structural characteristics of materials under different load conditions at the micrometer and nanometer scales. In-situ test benches can achieve different environmental conditions, such as temperature, humidity, and atmosphere, to replicate the actual service environment, and then conduct mechanical property tests on materials to understand the mechanical properties of materials under different stress and strain conditions, such as strength, toughness, and elastic modulus. The combination of the two can observe the microstructural changes of materials in actual service environments in real time, obtain the structural characteristics of a certain area of ​​the material in dynamic state and at a specific moment, continuously measure and characterize the micromechanical properties of the material, and gain a deeper understanding of the dynamic evolution of the material's mechanical properties and microstructure.

[0005] In mechanical tests, due to the low precision of the loading equipment or the complexity of the test design, the specimen will inevitably slip and experience temperature concentration, especially at the contact surface between the clamping device and the specimen, which will affect the mechanical observation results of the inspection area. In summary, the in-situ test of the micromechanical properties of artificial joints still needs to reproduce the actual service environment, use SEM for characterization observation, explore the deformation mechanism of the microstructure, and solve the stress concentration phenomenon, which is conducive to the accurate evaluation of the evolution of the microstructure and failure mechanism of the material. In combination with the urgent need for the durability of artificial joint materials under actual service conditions, the present invention develops an artificial joint in-situ testing machine with a variable curvature microchannel to realize anisotropic clamps, which is very necessary. Summary of the Invention

[0006] The purpose of the present invention is to provide an artificial joint in-situ testing machine based on a variable curvature microfluidic channel fixture and a method of using the same. A variable curvature microfluidic channel combining a semicircle and an arc is set in the flexible gasket to achieve force anisotropy. The semicircular microfluidic channel avoids stress concentration, and the arc microfluidic channel realizes the interaction between the flow of liquid medium and the sample observation area.

[0007] To achieve the above-mentioned objectives, the present invention provides an artificial joint in-situ testing machine based on a variable curvature microfluidic fixture, comprising a driving unit, a fixture testing unit and a moving unit on a platform base, the driving unit being located on one side of the platform base, the driving unit and the moving unit being connected through a gear transmission assembly, the moving unit being respectively connected to the fixture assembly and the test assembly of the fixture testing unit through a slider assembly, the liquid pool of the fixture testing unit being located in the center of the platform base, the fixture assembly being located inside the liquid pool, and a temperature control assembly being also provided inside the liquid pool.

[0008] Preferably, the servo motor of the driving unit is connected to the platform base through the servo motor support seat, the output shaft of the servo motor is connected to the first gear of the gear transmission assembly, the second gear of the gear transmission assembly is sleeved on the first transmission rod of the mobile unit, and the first gear is meshed with the second gear.

[0009] Preferably, worms are provided at both ends of the first transmission rod of the mobile unit, the worms are engaged with the worm gear on the second transmission rod, and the second transmission rod is symmetrically provided with transmission thread parts with opposite thread directions, and the transmission thread parts are threadedly connected to the slider assembly. The two ends of the first transmission rod are connected to the platform base through the first support seat and the second support seat respectively, and the angle between the first transmission rod and the second transmission rod is 90°.

[0010] Preferably, the platform base is provided with a measuring assembly on a side of the slider assembly away from the liquid pool, and a grating reading head is provided on the grating ruler of the measuring assembly. The grating ruler is connected to the platform base, and the grating reading head is connected to the first slider of the slider assembly.

[0011] Preferably, the first slider of the slider assembly is connected to one side of the force measuring piece of the test assembly. The cross-section of the force measuring piece is a U-shaped structure. Sliding grooves are symmetrically provided on both sides of the force measuring piece. The sliding grooves are slidingly connected to the side walls of the liquid pool. The rear side of the force measuring piece is connected to one end of the mechanical sensor in the liquid pool, and the other end of the mechanical sensor is connected to the left clamp of the clamp assembly through a connector.

[0012] Preferably, the second slider of the slider assembly is connected to one side of the motor fixing frame, and the side of the motor fixing frame away from the left clamp is connected to the waterproof motor, and the waterproof motor passes through the motor fixing frame and is connected to the right clamp.

[0013] Preferably, the electric heating rod and the waterproof temperature measuring probe of the temperature control component are both located inside the liquid pool.

[0014] Preferably, the left clamp and the right clamp have the same structure, a clamp cover is connected to the top of the left clamp, a test slot is provided between the left clamp and the clamp cover, a flexible gasket is provided at the bottom of the test slot, a semicircular microfluidic channel and an arc microfluidic channel are provided on the flexible gasket, the semicircular microfluidic channel and the arc microfluidic channel are connected, the semicircular microfluidic channel is composed of several microfluidic channels with uniformly increasing radii and the same center, and the width of the arc microfluidic channel is the same as the width of the semicircular microfluidic channel.

[0015] Preferably, the number of the second transmission rods is one on each side of the left and right sides of the liquid pool, and the two ends of the second transmission rod are connected to the platform base through the third support seat and the fourth support seat respectively, and the second transmission rod passes through the third support seat and is connected to the worm gear.

[0016] The method for using the artificial joint in-situ testing machine based on the variable curvature microfluidic fixture comprises the following steps:

[0017] S1. Start the servo motor of the driving unit to drive the second transmission rod of the moving unit to rotate, adjust the distance between the left clamp and the right clamp of the clamp assembly, and monitor the movement distance of the slider assembly by the measuring assembly;

[0018] S2. Connect the two ends of the test sample to the left and right clamps respectively, and tighten the clamp covers so that the test sample presses the flexible gasket;

[0019] S3. Add synovial fluid to the liquid pool, turn on the electric heating rod to heat the synovial fluid, and monitor the temperature of the synovial fluid using a waterproof temperature control probe;

[0020] S4. Start the waterproof motor to drive the fixture assembly and the test sample to rotate, and the mechanical sensor monitors the mechanical data.

[0021] Therefore, the present invention adopts an artificial joint in-situ testing machine based on a variable curvature microfluidic fixture and a method of using the above structure, and its beneficial effects are:

[0022] 1. The in-situ testing machine provided by the present invention has a compact structure and a main body size of 240 mm × 232 mm × 80 mm, which is suitable for most scanning electron microscope sample chambers;

[0023] 2. The in-situ testing machine provided by the present invention can replicate the service environment of artificial joint specimens, including constructing a liquid environment and a temperature environment to accurately simulate the environmental conditions of artificial joints in actual use. This covers the complex motion and different stress conditions in the joint fluid environment, enabling in vitro mechanical testing of prosthetic materials and preventing environmental factors from affecting the macroscopic and micro-area mechanical performance evaluation results of the test specimens.

[0024] 3. The flexible gasket provided by the present invention is provided with interconnected semicircular microchannels and arc microchannels. When the flexible gasket is squeezed, its contact area with the test sample is expanded, thereby increasing the static friction between the contact surface of the fixture assembly and the test sample, thereby avoiding unstable factors such as displacement of the test sample during the test process.

[0025] 4. The present invention provides a variable curvature microchannel that combines a semicircle and an arc to achieve force anisotropy. The semicircular microchannel avoids stress concentration, and the arc microchannel realizes the interaction between the flow of the liquid medium and the sample observation area. At the same time, the wall microchannel opening is a gradually expanding channel, which accelerates the flow of the liquid in the microchannel, avoids temperature concentration, and makes the temperature distribution uniform.

[0026] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of an artificial joint in-situ testing machine based on a variable curvature microfluidic fixture of the present invention;

[0028] Figure 2 This is a schematic diagram of the side view of the connection of the clamp assembly in the present invention;

[0029] Figure 3 This is a schematic structural diagram of the flexible gasket and the left clamp in the present invention;

[0030] Figure 4 is a two-dimensional graph of friction force-time in the test example of the present invention;

[0031] Figure 5 Schematic diagram of the test structure connection in the test example of the present invention;

[0032] Figure 6 This is a gasket-sample temperature distribution diagram in the test example of the present invention.

[0033] Reference numerals:

[0034] 1. Servo motor; 2. Servo motor support seat; 3. First gear; 4. First support seat; 5. Worm gear; 6. Platform base; 7. First transmission rod; 8. Worm; 9. Second support seat; 10. Third support seat; 11. Nut; 12. Grating scale; 13. Grating reading head; 14. Second transmission rod; 15. First movable connecting piece; 16. Fourth support seat; 17. First slider; 18. Slide rail; 19. Liquid pool; 20. Force measuring piece; 21. Mechanical sensor; 22. Connector; 23. Heating rod; 24. Left fixture; 25. Fixture cover; 26. Waterproof temperature probe; 27. Test sample; 28. Right fixture; 29. ​​Motor fixing bracket; 30. Waterproof motor; 31. Computer; 32. Instruments and meters; 33. Power supply. DETAILED DESCRIPTION

[0035] The present invention is further described below with reference to the accompanying drawings and examples. Unless otherwise defined, technical or scientific terms used herein shall have the same meanings as those commonly understood by persons of ordinary skill in the art to which the present invention pertains. The above-mentioned features or features described in the specific examples of the present invention may be combined in any manner. These specific examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention.

[0036] Example 1

[0037] like Figure 1As shown, the present invention provides an artificial joint in-situ testing machine based on a variable curvature microfluidic fixture, comprising a drive unit, a fixture test unit, and a mobile unit on a platform base 6. The drive unit is located on one side of the platform base 6, and the drive unit and the mobile unit are connected by a gear transmission assembly. The mobile unit is respectively connected to the fixture assembly and the test assembly of the fixture test unit through a slider assembly, and the liquid pool 19 of the fixture test unit is located in the center of the platform base 6. The fixture assembly is located inside the liquid pool 19, and a temperature control assembly is also provided inside the liquid pool 19.

[0038] The in-situ testing machine in this embodiment has a compact structure, with a main body size of 240 mm × 232 mm × 80 mm. It is suitable for most scanning electron microscope sample chambers and facilitates the acquisition of structural feature images of the test sample under different load conditions. The platform base 6 is fixed by threaded connection to other rigid bases. The drive unit drives the movement of the mobile unit, which drives the clamp assembly in the clamp test unit through the slider assembly. The clamp assembly clamps and fixes the test sample 27, and the test assembly measures the mechanical data of the test sample 27. The liquid pool 19 provides the actual operating temperature of the test sample 27 in the body. The temperature control assembly heats the synovial fluid in the liquid pool 19 and controls it to maintain the operating temperature.

[0039] The in-situ testing machine uses an external power supply 33 to power each unit. Data from the test assembly, temperature control assembly, and grating ruler 12 is transmitted to a cooperating instrument 32 using existing technology. Computer 31 controls the parameters of the temperature control assembly using existing technology. The grating ruler 12 and grating readhead 13, in conjunction with the instrument 32, collect and analyze test data such as displacement and temperature.

[0040] The drive unit's servo motor 1 is connected to the platform base 6 via a servo motor support 2. The servo motor's output shaft is connected to the first gear 3 of the gear transmission assembly. The second gear of the gear transmission assembly is mounted on the first transmission rod 7 of the mobile unit, with the first gear 3 meshing with the second gear. When the servo motor 1 is activated, it rotates the first gear 3, which in turn rotates the first transmission rod 7 via the second gear. Both the first gear 3 and the second gear are bevel gears.

[0041] The mobile unit's first transmission rod 7 is fitted with worm gears 8 at both ends, meshing with the worm gear 5 on the second transmission rod 14. The second transmission rod 14 is symmetrically threaded with oppositely oriented transmission threads, which are threadedly connected to the slider assembly. The first transmission rod 7 is connected to the platform base 6 via the first support 4 and second support 9, respectively, at a 90° angle between the first transmission rod 7 and the second transmission rod 14.

[0042] The rotation of the first transmission rod 7 drives the worm 8, which in turn drives the worm wheel 5 below it, which in turn drives the second transmission rod 14. The second transmission rod 14, through its oppositely threaded transmission threaded portion, drives the nut 11 threadedly connected to it. The nut 11 drives the slider assembly connected to it, thereby adjusting the position of the clamp assembly. The arrangement of the first support base 4 and the second support base 9 ensures the smooth rotation of the first transmission rod 7, to which it is hinged.

[0043] The platform base 6 is equipped with a measurement assembly on the side of the slider assembly away from the liquid pool 19. A grating readhead 13 is mounted on the measuring assembly's grating scale 12. The grating scale 12 is connected to the platform base 6, and the grating readhead 13 is connected to the first slider 17. The grating readhead 13 measures the displacement data of the fixture assembly by monitoring the displacement of the slider assembly.

[0044] The first slider 17 of the slider assembly is connected to one side of the test assembly's force-measuring member 20, which has a U-shaped cross-section. Sliding grooves are symmetrically arranged on either side of the force-measuring member 20, which slides into contact with the sidewalls of the liquid reservoir 19. The rear end of the force-measuring member 20 is connected to one end of a force sensor 21 within the liquid reservoir 19. The other end of the force sensor 21 is connected to the left clamp 24 of the fixture assembly via a connector 22.

[0045] The sliding groove on the force-measuring member 20 facilitates smooth movement of the force gauge along the liquid pool 19, driven by the first slider 17. A first movable connector 15 is provided on the first slider 17. The portion of the first movable connector 15 protruding from the first slider 17 is connected to the side wall of the force-measuring member 20. The provision of the first movable connector 15 ensures that the movement of the first slider 17 is not affected by the force-measuring member 20.

[0046] The force sensor 21 is a twin-screw force sensor. A threaded groove is provided on the rear side of the force measuring member 20. This groove is threadedly connected to a screw at one end of the force sensor 21, while the screw at the other end of the force sensor 21 is threadedly connected to a connector 22. While the force sensor 21 measures the mechanical data of the test piece, its twin-screw structure ensures that the fixture assembly can rotate under the power of the waterproof motor 30.

[0047] The second slider of the slider assembly is connected to one side of the motor fixing frame 29 . The side of the motor fixing frame 29 away from the left clamp 24 is connected to the waterproof motor 30 . The waterproof motor 30 passes through the motor fixing frame 29 and is connected to the right clamp 28 .

[0048] The second slider is equipped with a second movable connector. The portion of the second movable connector protruding from the second slider is connected to a motor mount 29. Driven by the second slider, motor mount 29 moves relative to liquid pool 19. Once the ends of the test piece are connected to left fixture 24 and right fixture 28, respectively, waterproof motor 30 is activated to rotate the test piece, left fixture 24, connector 22, and force sensor 21 through right fixture 28.

[0049] The temperature control assembly's heating rod 23 and waterproof temperature probe 26 are both located within the liquid pool 19. The heating rod 23 is a submersible type. During operation, the temperature control assembly remains below the surface of the synovial fluid. The heating rod 23 heats the synovial fluid within the liquid pool 19, while the waterproof temperature probe 26 monitors the synovial fluid temperature, ensuring that the synovial fluid accurately reaches the service environment temperature of the test piece.

[0050] like Figure 2 and Figure 3 As shown, the left fixture 24 and the right fixture 28 have identical structures. A fixture cover 25 is connected to the top of the left fixture 24, and a test slot is located between the left fixture 24 and the fixture cover 25. A flexible gasket with a variable curvature is located at the bottom of the test slot. A semicircular microfluidic channel and an arcuate microfluidic channel are arranged on the flexible gasket. The semicircular microfluidic channel is located away from the test slot opening, while the arcuate microfluidic channel is located closer to the test slot opening. The semicircular microfluidic channel is composed of several microfluidic channels with uniformly increasing radii and the same center. The width of the arcuate microfluidic channel is the same as that of the semicircular microfluidic channel.

[0051] The test piece is fixed between the fixture cover 25 and the flexible gasket. By controlling the degree of tightening of the fixture cover 25, the test piece squeezes the flexible gasket to varying degrees. Under the action of pressure, the flexible gasket deforms and has different contact areas with the test piece. In any direction of pressure, the test sample 27 is perpendicular to the tangent of the semicircular microchannel, achieving force anisotropy, greater resistance to dislocation movement, and increasing the static friction coefficient to solve the stress concentration problem. The arc microchannel is close to the electron microscope observation area, which is conducive to the circulation of the liquid medium in the tensile direction, realizing the interaction between the liquid flow and the electron microscope observation area of ​​the sample.

[0052] The setting of the semicircular microchannel and the arc microchannel ensures that after the test piece contacts the flexible gasket, the vertical cross-section of the flexible gasket presents a flow channel opening that is larger than the spacing between the hole walls, forming a gradually expanding channel, accelerating the flow of synovial fluid to carry away heat, and the distance from the electron microscope observation area is inversely proportional to the width of the flow channel opening, avoiding the influence of temperature concentration caused by the contact between the flexible gasket and the fixture assembly on the mechanical test results.

[0053] The number of second transmission rods 14 is one on each side of the liquid pool 19. The ends of the second transmission rods 14 are connected to the platform base 6 through the third support base 10 and the fourth support base 16, respectively. The second transmission rods 14 extend through the third support base 10 and are connected to the worm gear 5. The number of second transmission rods 14 ensures that the clamp assembly is driven by slider assemblies on both sides, ensuring smooth movement of the clamp assembly. Slide rails 18 are connected to the tops of the third support base 10 and the fourth support base 16. Slide rails 18 are slidably connected to the middle of the first slider 17 and the middle of the second slider.

[0054] Example 2

[0055] The method for using the artificial joint in-situ testing machine based on the variable curvature microfluidic fixture in Example 1 comprises the following steps:

[0056] S1. Start the servo motor of the driving unit to drive the second transmission rod of the moving unit to rotate, adjust the distance between the left clamp and the right clamp of the clamp assembly, and monitor the movement distance of the slider assembly by the measuring assembly.

[0057] S2. Connect the two ends of the sample to be tested to the test slots of the left fixture and the right fixture respectively, and tighten the fixture covers so that the sample to be tested presses the flexible gasket in the test slots.

[0058] S3. Add synovial fluid to the liquid pool, turn on the electric heating rod to heat the synovial fluid, and monitor the temperature of the synovial fluid through the waterproof temperature control probe.

[0059] S4. Start the waterproof motor to drive the fixture assembly and the test sample to rotate, and the mechanical sensor monitors the mechanical data.

[0060] Test Example 1

[0061] No gasket, ordinary gasket and flexible gasket of the present invention are respectively set in the left and right clamps, and the test sample is set to move left and right. Friction simulation analysis is performed on the contact surface between the test sample and each gasket. The results are as follows: Figure 4 The flexible gasket of the present invention increases the average static friction between the sample and the fixture assembly by 19.2% compared to conventional gaskets and 83.9% compared to no gasket. The stress distribution between the contact surface of the fixture assembly and the sample to be tested is uniform, and the fixing effect is enhanced.

[0062] like Figure 5 As shown, a common gasket and a flexible gasket provided by the present invention are set, and the temperature distribution results of the gasket-test sample are as follows. Figure 6 As shown, in the experimental simulation, the temperature of the sample portion contacted by the ordinary gasket on the right is 10.5% higher than that of the variable curvature microchannel gasket on the left, proving that the flexible gasket provided by the present invention can solve the temperature concentration problem due to its variable curvature texture.

[0063] Therefore, the present invention adopts the above-mentioned structure to form an artificial joint in-situ testing machine based on a variable curvature microchannel fixture and its use method. A variable curvature microchannel combining semicircles and arcs is set in the flexible gasket to achieve force anisotropy. The semicircular microchannel avoids stress concentration, and the arc microchannel realizes the interaction between the flow of liquid medium and the sample observation area.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An artificial joint in-situ testing machine based on a variable curvature microfluidic fixture, characterized by: It includes a drive unit, a fixture test unit and a mobile unit on the platform base. The drive unit is located on one side of the platform base. The drive unit and the mobile unit are connected by a gear transmission assembly. The mobile unit is respectively connected to the fixture assembly and the test assembly of the fixture test unit through a slider assembly. The liquid pool of the fixture test unit is located in the center of the platform base. The fixture assembly is located inside the liquid pool. A temperature control assembly is also provided inside the liquid pool. The first slider of the slider assembly is connected to one side of the force-measuring piece of the test assembly. The cross-section of the force-measuring piece is U-shaped. Sliding grooves are symmetrically provided on both sides of the force-measuring piece. The sliding grooves are slidably connected to the side walls of the liquid pool. The rear side of the force-measuring piece is connected to one end of the force sensor in the liquid pool. The other end of the force sensor is connected to the left clamp of the fixture assembly through a connector. The second slider of the slider assembly is connected to one side of the motor fixing frame. The side of the motor fixing frame away from the left clamp is connected to a waterproof motor. The waterproof motor passes through the motor fixing frame and is connected to the right clamp. The left fixture and the right fixture have the same structure. A fixture cover is connected to the top of the left fixture. A test slot is provided between the left fixture and the fixture cover. A flexible gasket is provided at the bottom of the test slot. A semicircular microfluidic channel and an arc microfluidic channel are provided on the flexible gasket. The semicircular microfluidic channel and the arc microfluidic channel are connected. The semicircular microfluidic channel is composed of several microfluidic channels with uniformly increasing radii and the same center. The width of the arc microfluidic channel is the same as that of the semicircular microfluidic channel.

2. The artificial joint in-situ testing machine based on the variable curvature microfluidic fixture according to claim 1, characterized in that: The servo motor of the driving unit is connected to the platform base through the servo motor support seat, the output shaft of the servo motor is connected to the first gear of the gear transmission assembly, the second gear of the gear transmission assembly is sleeved on the first transmission rod of the mobile unit, and the first gear is meshed with the second gear.

3. The artificial joint in-situ testing machine based on the variable curvature microfluidic fixture according to claim 2, characterized in that: Worms are provided at both ends of the first transmission rod of the mobile unit, and the worms are engaged with the worm gear on the second transmission rod. The second transmission rod is symmetrically provided with transmission thread parts with opposite thread directions, and the transmission thread parts are threadedly connected to the slider assembly. The two ends of the first transmission rod are respectively connected to the platform base through the first support seat and the second support seat, and the angle between the first transmission rod and the second transmission rod is 90°.

4. The artificial joint in-situ testing machine based on the variable curvature microfluidic fixture according to claim 1, characterized in that: A measuring component is provided on the platform base at a side of the slider component away from the liquid pool, and a grating reading head is provided on the grating ruler of the measuring component.

5. The artificial joint in-situ testing machine based on the variable curvature microfluidic fixture according to claim 1, characterized in that: The heating rod and waterproof temperature probe of the temperature control component are both located inside the liquid pool.

6. The artificial joint in-situ testing machine based on the variable curvature microfluidic fixture according to claim 3, characterized in that: The number of the second transmission rods is one on each side of the liquid pool. Both ends of the second transmission rod are connected to the platform base through the third support seat and the fourth support seat respectively. The second transmission rod passes through the third support seat and is connected to the worm gear.

7. A method for using an artificial joint in-situ testing machine based on a variable curvature microfluidic fixture according to any one of claims 1 to 6, characterized in that: The following steps are included: S1. Start the servo motor of the driving unit to drive the second transmission rod of the moving unit to rotate, adjust the distance between the left clamp and the right clamp of the clamp assembly, and monitor the movement distance of the slider assembly by the measuring assembly; S2. Connect the two ends of the test sample to the left and right clamps respectively, and tighten the clamp covers so that the test sample presses the flexible gasket; S3. Add synovial fluid to the liquid pool, turn on the electric heating rod to heat the synovial fluid, and monitor the temperature of the synovial fluid using a waterproof temperature control probe; S4. Start the waterproof motor to drive the fixture assembly and the test sample to rotate, and the mechanical sensor monitors the mechanical data.

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