An optical interferometry device for studying water lubrication properties of bionic soft material surfaces

Abstract

The present invention discloses an optical interferometric measurement device for studying the water lubrication performance of the surface of a bionic soft material, comprising a rotating system, a microscope system and a loading system installed on a stand, wherein the loading system comprises a translation mechanism and a lever mechanism installed on the translation mechanism, wherein the lever mechanism comprises a lever body and a contact body and a leveling mechanism connected to both ends thereof, wherein a fine-tuning weight is slidingly arranged on the loading side of the lever body; the rotating system is connected to a contact disk, wherein an annular structure made of bionic soft material is embedded in the contact disk; the translation mechanism is used to adjust the contact between the contact body and the annular structure, the lever mechanism is used to adjust the contact load of the contact body on the annular structure, and the microscope system is used to observe and record experimental data. The present invention achieves the purpose of in-situ observation of the change of the water lubrication film of the contact pair under a small continuously changing contact stress by making the bionic soft material into an annular structure in contact with the contact body, arranging a leveling mechanism on the lever mechanism for leveling, and fine-tuning with a fine-tuning weight.

Description

Technical Field

[0001] The invention relates to the technical field of research on lubrication properties of material surfaces, and in particular to an optical interference measurement device for researching water lubrication properties on the surface of bionic soft materials. Background Art

[0002] Mechanical sliding interfaces such as oil-immersed bearings and gears widely used in the industrial field belong to hard-hard contact, also known as rigid contact. At present, there is a mature theoretical system and experimental research device for the observation of the lubrication state and behavior mechanism of the sliding interface under hard-hard contact conditions, and the most common one is the optical interference thin film measurement device. However, in many engineering and biological sliding interface application fields, such as joint lubrication and eyelid contact in the human body, windshield wipers, tires, various seals, etc., the contact interface is mostly made of low elastic modulus materials and water-based lubrication. At this time, the contact condition is soft-hard / soft contact, also known as compliant contact. Compared with rigid oil-based contact, the lubrication behavior of compliant water-based contact interface is more complicated. This is because in addition to the interface fluid lubrication effect, the contact surface will also undergo large elastic deformation, that is, the fluid effect and elastic deformation jointly determine the lubrication state of the interface. In particular, due to the existence of elastic deformation effect, the traditional optical interference thin film device can no longer be used for the accurate measurement of the change in the thickness of the water lubrication film on the contact interface, and it is impossible to explain the lubrication mechanism under the compliant contact state from a scientific level, so it is impossible to guide the directional design of actual water-lubricated materials.

[0003] Implantable bionic lubricating materials, such as bionic articular cartilage, contact lenses, anti-adhesive barrier films, or functional coatings on the surface of biomedical devices, are all slippery elastic materials that meet the compatibility with the human tissue modulus during use. In the hydrated state, this type of slippery elastic material not only exhibits excellent lubrication effect to reduce the friction of the sliding interface, but is also often accompanied by compliant deformation during the contact process to dissipate large mechanical stresses at the interface. At present, from a scientific point of view, it is difficult to accurately observe and measure the lubricating film of bionic elastic materials in the hydrated state. In recent years, domestic and foreign research reports have shown that optical interferometry can be used to measure interfacial lubricating films, but it is limited to oil-based hard contact lubrication interfaces.

[0004] Some measuring devices are disclosed in the prior art. For example, the Chinese patent with the authorization announcement number CN 107402098 B discloses a lubricating film measuring device, which uses a rotary device to fix and clamp the glass disk, and uses a motor to drive the glass disk to rotate, so as to provide a rotating glass disk contact plane for the steel ball; in the ball-driven loading rotary device, the steel ball is fixed to the servo motor shaft, and the servo motor is fixed to the force-bearing end of the lever, and a standard weight is placed at a fixed position at the loading end of the lever to provide a load for the contact between the steel ball and the glass disk. For another example, the Chinese patent with the authorization announcement number CN 101458068 B discloses a device for measuring the lubricating film between a micro-slider and a glass disk, which contacts the micro-slider with the glass disk at a certain small angle, and its contact pair is also hard-hard contact; it uses a similar lever loading mechanism and also lacks the need to provide a small contact stress that meets the biomechanical properties to the contact area.

[0005] From the above content, it can be seen that the existing optical interferometry film thickness measurement technology all adopts the hard-hard contact form at the GPa level, while the contact interface of soft matter involves low elastic modulus materials, and the interface contact stress during sliding shear is at the KPa-MPa level. Therefore, the existing technology ignores the important role played by the elastic deformation of soft matter materials in lubrication film formation, that is, it is not suitable for the study of the lubrication state of elastic soft matter contact interfaces. Furthermore, the existing technology does not have the function of continuous dynamic loading and is not suitable for simulating the dynamic loading process of elastic biological lubrication interfaces. Therefore, the existing optical interferometry film thickness measurement technology can no longer meet the research needs of the lubrication state and mechanism of bionic soft matter elastic interfaces.

[0006] Some of the terms are explained below:

[0007] Compliant contact: When the elastic modulus of one or two contacting surfaces is low, a soft solid or a hard-soft solid contact combination is formed, that is, compliant contact, such as the contact between the rubber wiper and the glass of the car's front windshield, the knee joint in the human body, etc.

[0008] Isoviscosity-elastohydrodynamic lubrication (I-EHL): In the case of compliant contact, the contact pressure is large enough to cause elastic deformation of one or two interacting solids, but the pressure in the contact area is relatively low, not enough to cause any substantial change in the viscosity of the lubricant in the contact entrance. Compared with the hard-hard contact widely used in industry (such as bearings, gears, etc.), the lubrication mechanism under compliant contact is no longer elastic hydrodynamic lubrication (abbreviated as EHL) caused by fluid dynamic pressure effect. At this time, the large elastic deformation of the contact surface and the fluid dynamic pressure effect act together, and the contribution of the two to the thickness of the lubricating film changes with the changes in working conditions and time. It is in a more complex lubrication mechanism. This lubrication is called isoviscosity-elastohydrodynamic lubrication. Summary of the invention

[0009] The purpose of the present invention is to provide an optical interferometry measurement device for studying the water lubrication properties of the surface of bionic soft materials, so as to solve the problems existing in the above-mentioned prior art. The bionic soft material is made into a ring structure to contact the contact body, and a leveling mechanism is set on the lever mechanism for leveling. Fine-tuning is performed using fine-tuning weights, so as to achieve the purpose of in-situ observation of changes in the water lubrication film of the contact pair under small continuously changing contact stress.

[0010] To achieve the above object, the present invention provides the following solutions:

[0011] The present invention provides an optical interferometry measuring device for studying the water lubrication performance of the surface of a bionic soft material, comprising a platform and a rotation system, a microscope system and a loading system respectively mounted on the platform, wherein the loading system comprises a translation mechanism and a lever mechanism mounted on the translation mechanism, wherein the lever mechanism comprises a lever body and a contact body and a leveling mechanism respectively connected to the two ends of the lever body, wherein a fine-tuning weight is slidably arranged on the loading side of the lever body; the rotation system is connected to a contact disk and can drive the contact disk to rotate, wherein the contact disk is embedded with an annular structure made of a bionic soft material; the translation mechanism is used for adjusting the contact between the contact body and the annular structure, the lever mechanism is used for adjusting the contact load of the contact body on the annular structure, and the microscope system is used for observing and recording experimental data.

[0012] Preferably, the contact plate comprises a grooved glass plate and the annular structure embedded in the grooved glass plate, and the annular structure comprises an annular body made of PDMS material and a silver-plated layer arranged on the surface of the annular body.

[0013] Preferably, a loading guide rail is fixedly disposed on the lever body, and the fine-tuning weight is slidably disposed on the lever body via the loading guide rail.

[0014] Preferably, the leveling mechanism comprises a leveling screw connected to the lever body and a leveling block threadedly connected to the leveling screw.

[0015] Preferably, a first motor bracket is fixedly mounted on the lever body, a first servo motor is mounted on the first motor bracket, and the contact body is connected to the main shaft of the first servo motor via a first coupling.

[0016] Preferably, the stand comprises a support upper panel, a support lower panel and a support column supported between the support upper panel and the support lower panel.

[0017] Preferably, the translation mechanism comprises a translation plate for mounting the lever mechanism and a translation guide rail fixed to an upper panel of the bracket, and the translation plate is slidably disposed on the translation guide rail.

[0018] Preferably, the rotating system includes a second motor bracket installed on the upper panel of the bracket and an outer sleeve, the second motor bracket is fixedly connected to a second servo motor, the main shaft of the second servo motor is connected to a rotating shaft through a second coupling, the rotating shaft is rotatably arranged in the outer sleeve, and is connected to the contact plate after passing through the outer sleeve.

[0019] Preferably, the microscope system includes a U-shaped bracket fixedly mounted on a panel of the bracket, the inner side of the U-shaped bracket can form a moving channel for the contact body, the U-shaped bracket is provided with a microscope translation stage, a support rod connected by the microscope translation stage and a clamping seat connected to the support rod, and the clamping seat is connected to a microscope assembly.

[0020] Preferably, the microscope assembly comprises a lens frame connected to the clamping seat and a microscope body connected to the lens frame, wherein a lens is arranged at one end of the microscope body facing the contact plate, and a CCD connector and a light source connector are arranged at the other end.

[0021] Compared with the prior art, the present invention has achieved the following technical effects:

[0022] (1) The present invention forms a bionic soft material into an annular structure to contact a contact body, arranges a leveling mechanism on a lever mechanism for leveling, and uses a fine-tuning weight for fine-tuning. This can provide correct stress conditions for a bionic water-based soft material whose working environment is kPa to MPa, thereby achieving the purpose of in-situ observation of changes in the water lubrication film of the contact pair under a small continuously changing contact stress. The dynamic formation process of the hydration film is observed in situ using a microscope system, and the thickness of the water film between interfaces can be accurately measured. This provides a feasible technical means for evaluating the lubrication performance of bionic lubricating materials and studying the lubrication mechanism between interfaces of bio-lubricating materials, and clarifies the core factors that affect the lubrication performance, so as to provide necessary guidance for the design of bionic lubricating materials from the perspective of lubrication.

[0023] (2) The present invention can simulate the deformation of water-based elastic materials under shear conditions by arranging bionic soft materials on the contact disk, and can realize the sliding interface of the soft-hard contact pair, thereby solving the problem that the existing test bench lever loading mechanism cannot provide continuous micro-Hertzian contact stress that meets biomechanical requirements and cannot analyze the biolubrication characteristics of composite materials combining low elastic modulus soft materials with high elastic modulus hard materials. The present invention can be used to measure the influence of the deformation of low elastic modulus soft materials on the evolution of lubrication state. The present invention can realize continuous contact stress loading by arranging fine-tuning weights on the lever body and leveling by the leveling mechanism, thereby simulating the dynamic load process of elastic biolubrication interfaces such as joints.

[0024] (3) The present invention constructs a set of soft-hard contact pairs by pouring soft lubricating material into the glass groove. The optical interference measurement technology can be used to measure the lubricating film under the condition of large elastic deformation, which can better explain the unique lubrication mechanism of soft material under the combined action of surface elastic deformation and fluid dynamic pressure effect; the existing lever and weight loading mechanism is abandoned, and a new lever mechanism designed according to the blade pivot principle is adopted, which solves the problem that the existing lever and weight loading cannot provide continuous low contact stress loading, and provides a novel technical means for evaluating the lubrication performance of soft material under low contact stress compliant contact, and provides a novel technical evaluation means for evaluating the lubrication characteristics of composite bionic materials under continuous low contact stress and compliant contact; by revealing its complex lubrication mechanism, it can provide theoretical guidance for the structural design of materials, for example, it can be used to study the complex lubrication mechanism of hard-soft composite materials (such as articular hard bone-articular cartilage) under continuous low contact stress compliant contact. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 It is a schematic diagram of the structure of the bench of the present invention;

[0028] Figure 3 This is a schematic diagram of the structure of the loading system of the present invention;

[0029] Figure 4 It is a schematic diagram of the structure of the microscope system of the present invention;

[0030] Figure 5 It is a schematic diagram of the structure of the rotating system of the present invention;

[0031] Figure 6 This is a schematic diagram of the structure of the contact disk of the present invention;

[0032] Figure 7 This is a schematic diagram of the lever mechanism of the present invention;

[0033] Among them, 1. Stage; 2. Loading system; 3. Microscope system; 4. Rotation system;

[0034] 11. Bracket lower panel; 12. Bracket column; 13. Bracket upper panel; 14. Bottom plate support feet;

[0035] 21. Leveling screw; 22. Leveling block; 23. Loading guide rail; 24. Fine-tuning weight; 25. First servo motor; 26. First motor bracket; 27. Contact body; 28. Translation plate; 29. ​​Translation guide rail; 210. First coupling; 211. First support plate; 212. Second support plate; 213. Lever support shaft; 214. Lever body;

[0036] 31. Lens; 32. Microscope body; 33. Light source connector; 34. First locking button; 35. CCD connector; 36. Second locking button; 37. Lens holder; 38. Clamping seat; 39. Support rod; 310. Translation stage slider; 311. Microscope translation stage; 312. U-shaped bracket;

[0037] 41. Second coupling; 42. First rolling bearing; 43. Second rolling bearing; 44. Pressing nut; 45. Contact plate; 451. Grooved glass plate; 4511. Annular groove; 452. Annular structure; 46. Rotating shaft; 47. Outer sleeve; 48. Second motor bracket; 49. Second servo motor. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] The purpose of the present invention is to provide an optical interferometry measurement device for studying the water lubrication properties of the surface of bionic soft materials, so as to solve the problems existing in the prior art. The bionic soft material is made into a ring structure to contact the contact body, and a leveling mechanism is set on the lever mechanism for leveling. Fine-tuning is performed using fine-tuning weights, so as to achieve the purpose of in-situ observation of changes in the water lubrication film of the contact pair under small continuously changing contact stress.

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] like Figures 1 to 6As shown, the present invention provides an optical interferometric measurement device for studying the water lubrication performance of the surface of a bionic soft material, comprising a stand 1 and a rotating system 4, a microscope system 3 and a loading system 2 respectively mounted on the stand 1, wherein the stand 1 serves as a support and fixing structure for each system to connect each system into a whole. Among them, the loading system 2 comprises a translation mechanism and a lever mechanism mounted on the translation mechanism, the lever mechanism comprises a lever body 214 and a contact body 27 respectively connected to both ends of the lever body 214 and a leveling mechanism, the contact body 27 can be a sphere, for example, a steel ball, a ceramic ball, etc.; a fine-tuning weight 24 is slidably provided on the loading side of the lever body 214. The lever body 214 can adopt a plate-like structure or a rod-like structure, and the fulcrum adopts a lever support shaft 213, so that the lever body 214 rotates around the lever support shaft 213, the balance of the lever body 214 is achieved by adjusting the leveling mechanism, and the adjustment of the contact force of the contact body 27 is achieved by adjusting the position of the fine-tuning weight 24. The rotating system 4 is connected to a contact disk 45 and can drive the contact disk 45 to rotate. The contact disk 45 is embedded with an annular structure 452 made of bionic soft material. The contact disk 45 can be made of a transparent material, such as a glass disk, and the contact position of the contact pair formed by the contact body 27 and the annular structure 452 can be observed through the glass disk by the microscope system 3. The contact between the contact body 27 and the annular structure 452 can be adjusted by the translation mechanism to form a contact pair, which can be a hard-soft contact pair according to experimental requirements. Driven by the rotating system 4, the sliding contact movement between the contact body 27 and the annular structure 452 is realized. Under the action of the lever mechanism, the contact load of the contact body 27 on the annular structure 452 is adjusted, and since the fine-tuning weight 24 can slide continuously, continuous loading of the contact load can be achieved. The microscope system 3 is used to observe and record experimental data, such as in-situ observation of the dynamic formation process of the hydration film, and can accurately measure the thickness of the water film between the interfaces. The present invention makes the bionic soft material into an annular structure 452 in contact with the contact body 27, arranges a leveling mechanism on the lever mechanism for leveling, and uses the fine-tuning weight 24 for fine-tuning. It can provide correct stress conditions for the bionic water-based soft material with a working environment of kPa to MPa level, and achieve the purpose of in-situ observation of the change of the water lubrication film of the contact pair under a small continuously changing contact stress; the microscope system 3 is used to in-situ observe the dynamic formation process of the hydration film, and the thickness of the water film between the interfaces can be accurately measured. It provides a feasible technical means for evaluating the lubrication performance of bionic lubricating materials and studying the lubrication mechanism between the interfaces of biological lubricating materials, and clarifies the core factors affecting the lubrication performance, so as to provide necessary guidance for the design of bionic lubricating materials from the perspective of lubrication.

[0042] Combination Figure 6As shown, the contact disk 45 includes a grooved glass disk 451, on which an annular groove 4511 is provided, and an annular structure 452 is embedded in the annular groove 4511, and the annular structure 452 includes an annular body made of PDMS material and a silver-plated layer provided on the surface of the annular body. The present invention successfully obtains a soft-hard composite contact pair by providing an annular groove 4511 on the original glass disk raceway and preparing a transparent bionic elastic soft material (such as PMMA) on the raceway of the annular groove 4511, which can truly simulate the dynamic deformation process of low elastic modulus soft material and realize the observation and measurement of the interface lubrication state and lubricating film thickness of bionic water-based soft material. The present invention adopts the method of limiting the raceway of the annular groove 4511, and the depth of the annular groove 4511 can be precisely controlled, which can not only accurately control the thickness of the annular structure 452 (elastomer), but also ensure the mechanical stability of the interface during the shearing process, and prevent it from falling off from the contact area during the shearing process.

[0043] The manufacturing process of the contact plate 45 is as follows:

[0044] First, it is necessary to make a grooved glass plate 451 with an annular groove 4511. When making it, considering the imaging problem, the depth of the annular groove 4511 of the grooved glass plate 451 can be set to 3 mm in preparation for filling PDMS. Based on the original hard-hard glass plate with a diameter of 150 mm and the rolling track of the steel ball on the glass plate with a diameter of 126 mm, the width of the annular groove 4511 processed on the surface of the grooved glass plate 451 is determined to be 20 mm and the depth is 3 mm.

[0045] The specific processing method of the annular groove 4511 on the grooved glass plate 451 is as follows:

[0046] The annular groove 4511 of the above-mentioned size is processed on the surface of the original glass plate through a cutting process to ensure that the annular groove 4511 has a basically accurate geometric shape and size; the annular groove 4511 is processed to meet the above-mentioned size requirements through a rough grinding process; the surface of the annular groove 4511 is polished through a fine grinding process to meet the optical measurement requirements.

[0047] After the annular groove 4511 is processed, liquid dimethylsiloxane material (hereinafter referred to as PDMS) is poured into the annular groove 4511. It is a mixture of organic siloxanes with chain structures of different polymerization degrees and has optical transparency. The specific operation is as follows:

[0048] (1) Add liquid PDMS polymer and curing agent into a glass cup in a ratio of 10:1 and mix;

[0049] (2) Stir the mixed liquid in the glass cup with a paddle stirrer for 5 minutes at room temperature to obtain a uniform PDMS mixed solution;

[0050] (3) Place the glass in an ultrasonic cleaning machine for 10 to 20 minutes for ultrasonic treatment, add ice cubes to the water to prevent the PDMS from curing due to heat, and remove bubbles in the solution;

[0051] (4) Place the grooved glass plate 451 on a horizontal platform, and slowly inject the solution into the annular groove 4511 of the grooved glass plate 451 using a syringe to ensure that the entire annular groove 4511 is filled without overflowing. Then, place the grooved glass plate 451 filled with PDMS in a drying oven for drying and curing for 12 hours, with the temperature controlled at about 70°C.

[0052] In order to ensure optical imaging, a layer of silver film needs to be coated on the surface of PDMS. The specific process is as follows:

[0053] (1) First, prepare stannous chloride (SnCl 2 ) aqueous solution, 1850mL water and 185mL concentrated hydrochloric acid are mixed, shaken well, and then 185g stannous chloride powder is added. During the dissolution of stannous chloride, a glass rod is used to vigorously stir to prevent the hydrolysis of stannous chloride. Since the stannous chloride aqueous solution has a strong reducing property, it is not easy to store for a long time and needs to be prepared and used in the experiment;

[0054] (2) The grooved glass plate 451 filled with PDMS is completely immersed in a stannous chloride solution at room temperature for 20 minutes, so that a layer of stannous ions Sn is adsorbed on the surface of the PDMS. 2+ , then take out the grooved glass plate 451 and dry it in a vacuum drying oven at 50°C for 30 minutes;

[0055] (3) preparing a silver electrolyte solution and a reducing agent solution respectively: the silver electrolyte solution is prepared by mixing 7.4 g of silver nitrate, 1.85 mL of ethylenediamine and 740 mL of deionized water; the reducing agent solution is prepared by mixing 37 g of potassium sodium tartrate and 740 mL of deionized water; then, the silver electrolyte solution and the reducing agent solution are mixed to prepare a silver plating deposition solution;

[0056] (4) The glass disk adsorbed with stannous ions obtained in step (2) is immersed in the deposition solution in step (3) for 30 minutes at room temperature to perform chemical deposition on the PDMS surface. The silver ions in the solution react with the adsorbed stannous ions to produce the following chemical reaction:

[0057] Sn 2+ +2Ag + =Sn 4+ +2Ag

[0058] The reduced silver atoms will form nuclei at the position of the stannous ions, and then the silver ions in the deposition solution will be continuously reduced to silver nanoparticles by the reducing agent due to their catalytic activation, and finally a continuous silver-plated layer will be formed on the PDMS surface. During the deposition process, the deposition solution needs to be gently shaken to make the silver-plated layer evenly distributed. Then, the grooved glass plate 451 is taken out, and the surface of the PDMS silver-plated layer is repeatedly rinsed with deionized water, and dried in a vacuum drying oven at 50°C for 30 minutes.

[0059] It should be noted that silver nitrate is extremely unstable and easily decomposed by light, so the steps involving silver nitrate in the above process need to be protected from light. The thickness of the silver film is controlled at 30-50nm. Since the silver film is extremely thin, it does not affect the surface properties of PDMS.

[0060] like Figure 3 As shown, the lever body 214 can swing around the lever support shaft 213, and the lever support shaft 213 is mounted on the first support plate 211 and the second support plate 212, and the first support plate 211 and the second support plate 212 are fixed on the translation mechanism. A loading guide rail 23 is fixedly arranged on the lever body 214, and the direction of the loading guide rail 23 is consistent with the extension direction of the lever body 214. The fine-tuning weight 24 is slidably arranged on the lever body 214 through the loading guide rail 23. By moving the position of the fine-tuning weight 24 on the loading guide rail 23, the loading size of the loading side of the lever body 214 can be changed, thereby realizing the change of the contact force of the contact body 27.

[0061] The leveling mechanism may include a leveling screw 21 connected to the lever body 214 and a leveling block 22 threadedly connected to the leveling screw 21. By adjusting the position of the leveling block 22 on the leveling screw 21, the loading torque on the loading side of the lever body 214 can be adjusted, that is, the overall leveling of the lever mechanism is achieved.

[0062] The lever body 214 is fixedly mounted with a first motor bracket 26, which can be set in an L shape, with its lateral arm fixed on the lever body 214, and a horizontally arranged first servo motor 25 mounted on the vertical arm. The contact body 27 is connected to the main shaft of the first servo motor 25 through the first coupling 210. The contact body 27 can be driven to rotate by the first servo motor 25, so that the contact form between the contact body 27 and the annular structure 452 of the contact disk 45 can be controlled.

[0063] The present invention redesigns the lever mechanism of the loading system 2 and uses the lever balance principle to design a continuous loading device that can provide a small load (low contact stress, compliant deformation). This solves the problem that the lever and weight loading system in the traditional optical interference film thickness measurement device cannot provide a continuous small load, and can provide the contact area with a kPa to MPa level contact stress that conforms to the biomechanical properties.

[0064] Combination Figure 7 As shown, the loading principle of the lever mechanism is as follows:

[0065] The leveling block 22 is rotated and adjusted so that the contact body 27 (Fb) and the leveling block 22 (Fc) at both ends of the lever body 214 are balanced, as shown in formula (1). At this time, the contact pair is in a zero load state. Then, the position of the fine-tuning weight 24 (Fa) is adjusted according to the adjustment scale on the lever body 214. When the leveling block 22 (Fa) reaches the specified position, the contact pair obtains the corresponding contact load, as shown in formula (2):

[0066] F b ×L b =F c ×L c (1)

[0067] F+F b ×L b =F t ×L c +F a ×L a (2)

[0068] By using this lever mechanism, a continuously changing small load can be provided to the contact pair.

[0069] Among them, Lb is the distance from the center of the contact body 27 to the fulcrum, La is the distance from the mass center of the fine-tuning weight 24 to the fulcrum, Lc is the distance from the mass center of the leveling block 22 to the fulcrum, Fc is the mass of the leveling block 22, Fa is the mass of the fine-tuning weight 24, Fb is the mass of the contact body 27 and the motor part, and F is the loading load.

[0070] The leveling block 22 and the fine-tuning weight 24 solve the deficiency of the original lever-weight loading mechanism that can only load at least 0.5N, and can provide continuous small loads for the point contact area to meet the loading requirements of bionic lubrication kPa~MPa level contact stress.

[0071] like Figure 2 As shown, the stand 1 may include a support upper panel 13, a support lower panel 11, and a support column 12 supported between the support upper panel 13 and the support lower panel 11. The support upper panel 13 is provided with mounting holes for mounting various systems. A bottom plate support foot 14 may also be installed under the support lower panel 11 to stably support the stand 1 as a whole and to adjust the horizontal state of the stand 1.

[0072] Combination Figure 3As shown, the translation mechanism of the loading system 2 may include a translation plate 28 for mounting a lever mechanism and a translation guide rail 29 fixed to the upper panel 13 of the bracket, and the translation plate 28 is slidably arranged on the translation guide rail 29. Since the lever mechanism is fixedly arranged on the translation plate 28, the position of the contact body 27 can be adjusted by moving the position of the translation plate 28, so that the contact body 27 can be translated to below the contact disk 45, so that the two form a contact pair.

[0073] like Figure 5 As shown, the rotating system 4 may include a second motor bracket 48 and an outer sleeve 47 mounted on the bracket upper panel 13, the second motor bracket 48 is fixedly connected to a second servo motor 49, the main shaft of the second servo motor 49 is connected to a rotating shaft 46 through a second coupling 41, the rotating shaft 46 is rotatably arranged in the outer sleeve 47 through a first rolling bearing 42 and a second rolling bearing 43, and is connected to a contact plate 45 after passing through the outer sleeve 47. The contact plate 45 is fixed to the rotating shaft 46 through a clamping nut 44 and rotates with the rotating shaft 46.

[0074] like Figure 4 As shown, the microscope system 3 may include a U-shaped bracket 312 fixedly mounted on the bracket upper panel 13, and the inner side of the U-shaped bracket 312 can form a moving channel for the contact body 27 to avoid interference with the movement of the contact body 27. The U-shaped bracket 312 is provided with a microscope translation stage 311, a support rod 39 connected through the microscope translation stage 311, and a clamping seat 38 connected to the support rod 39, and the clamping seat 38 is connected to the microscope assembly. The support rod 39 is connected to the microscope translation stage 311 through a translation stage slider 310. By adjusting the position of the translation stage slider 310, the position of the support rod 39 can be adjusted, and then the position of the microscope assembly can be adjusted, so that the microscope assembly is aligned with the position of the contact pair.

[0075] The microscope assembly may include a lens holder 37 connected to a clamping seat 38 and a microscope body 32 connected to the lens holder 37, wherein a lens 31 is provided at one end of the microscope body 32 facing the contact plate 45, and a light source connector 33 and a CCD connector 35 are provided at the other end, and a first locking button 34 for locking the light source and a second locking button 36 for locking the CCD are respectively provided.

[0076] The present invention performs mechanical design on a hard glass disk, processes an annular groove 4511 in the contact raceway measurement area, fills the annular groove 4511 with a transparent bionic elastic soft material (such as PDMS), and successfully obtains a soft-hard composite contact pair; the improved glass disk contact pair can truly simulate the dynamic deformation process of low elastic modulus soft matter materials, realize the observation and measurement of the interface lubrication state and lubrication film thickness of bionic water-based soft materials, and meets the basic research needs of bionic lubrication materials.

[0077] Compared with the traditional method of adjusting the load by changing the mass of the weight, the lever mechanism in the loading system 2 of the present invention has the main advantage of being able to achieve mN-level precision adjustment, solving the problem that the original lever and weight loading system cannot provide continuous small loads, and can provide the contact area with continuous kPa~Mpa-level contact stress that conforms to biomechanical properties.

[0078] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An optical interferometry device for studying the water lubrication properties of bionic soft material surfaces. Features: It includes a stage and a rotating system, a microscope system and a loading system respectively installed on the stage, the loading system includes a translation mechanism and a lever mechanism installed on the translation mechanism, the lever mechanism includes a lever body and a contact body and a leveling mechanism respectively connected to the two ends of the lever body, and a fine-tuning weight is slidably provided on the loading side of the lever body; the rotating system is connected to a contact disk and can drive the contact disk to rotate, and the contact disk is embedded with an annular structure made of bionic soft material; the translation mechanism is used to adjust the contact between the contact body and the annular structure, the lever mechanism is used to adjust the contact load of the contact body on the annular structure, and the microscope system is used to observe and record experimental data.

2. The optical interferometry measuring device for studying the water lubrication properties of biomimetic soft material surfaces according to claim 1, Features: The contact plate comprises a grooved glass plate and the annular structure embedded on the grooved glass plate, and the annular structure comprises an annular body made of PDMS material and a silver-plated layer arranged on the surface of the annular body.

3. The optical interferometry measuring device for studying the water lubrication properties of biomimetic soft material surfaces according to claim 1, Features: A loading guide rail is fixedly arranged on the lever body, and the fine-tuning weight is slidably arranged on the lever body through the loading guide rail.

4. The optical interferometry measuring device for studying the water lubrication properties of biomimetic soft material surfaces according to claim 1, Features: The leveling mechanism comprises a leveling screw connected to the lever body and a leveling block threadedly connected to the leveling screw.

5. The optical interferometry measuring device for studying the water lubrication performance of biomimetic soft material surfaces according to claim 1, Features: A first motor bracket is fixedly mounted on the lever body, a first servo motor is mounted on the first motor bracket, and the contact body is connected to the main shaft of the first servo motor through a first coupling.

6. The optical interferometry measuring device for studying the water lubrication properties of biomimetic soft material surfaces according to any one of claims 1 to 5, Features: The stand comprises an upper support panel, a lower support panel and support columns supported between the upper support panel and the lower support panel.

7. The optical interferometry measuring device for studying the water lubrication properties of biomimetic soft material surfaces according to claim 6, Features: The translation mechanism comprises a translation plate for mounting the lever mechanism and a translation guide rail fixed to the upper panel of the bracket, and the translation plate is slidably arranged on the translation guide rail.

8. The optical interferometry measuring device for studying the water lubrication properties of biomimetic soft material surfaces according to claim 6, Features: The rotating system includes a second motor bracket installed on the upper panel of the bracket and an outer sleeve. The second motor bracket is fixedly connected to a second servo motor. The main shaft of the second servo motor is connected to a rotating shaft through a second coupling. The rotating shaft is rotatably arranged in the outer sleeve and is connected to the contact plate after passing through the outer sleeve.

9. The optical interferometry measuring device for studying the water lubrication performance of biomimetic soft material surfaces according to claim 6, Features: The microscope system includes a U-shaped bracket fixedly mounted on a panel of the bracket, the inner side of the U-shaped bracket can form a moving channel for the contact body, the U-shaped bracket is provided with a microscope translation stage, a support rod connected by the microscope translation stage, and a clamping seat connected to the support rod, and the clamping seat is connected to a microscope assembly.

10. The optical interferometry measuring device for studying the water lubrication performance of the surface of biomimetic soft materials according to claim 9, Features: The microscope assembly comprises a lens frame connected to the clamping seat and a microscope body connected to the lens frame. The microscope body is provided with a lens at one end facing the contact plate, and a CCD connector and a light source connector at the other end.

Images