In-situ mechanical testing device for scanning electron microscope

Abstract

The utility model provides a scanning electron microscope in situ mechanics experiment device relates to the field of mechanics test technology. Base realizes each module compact integration and coaxial assembly, adapts SEM vacuum narrow and small environment. Macro motion coarse adjustment module adopts step motor, ball screw and double guide rail transmission, realizes big stroke quick positioning, micro motion fine adjustment module passes through first micro drive spare and first flexible hinge drive anvil assembly, and sample micro motion platform realizes XY micro motion of object table with the help of second micro drive spare and second flexible hinge, and both reach nanometer level accurate loading and alignment in cooperation. After macro motion coarse adjustment, XY positioning, micro motion fine adjustment loading, can realize indentation, scratch and other multi -mode in situ mechanics test under SEM observation. Solve traditional device poor adaptability, insufficient precision, cumbersome operation and other problems, can accurate characterization micro - nanometer material intrinsic mechanics performance, be applicable to the microcosmic mechanics analysis of advanced material and device.

Description

Technical Field

[0001] This utility model relates to the field of mechanical testing technology, and in particular to an in-situ mechanical experimental device for scanning electron microscope. Background Technology

[0002] With the rapid iteration of micro / nano materials, thin-film devices, biomaterials, and MEMS (microelectromechanical systems), the mechanical properties and surface behavior of materials have become increasingly critical to the overall reliability of devices. At the micro or nanoscale, the dynamic behaviors of materials, such as deformation mechanisms, crack initiation and propagation paths, and interfacial bonding strength, differ significantly from those at the macroscale. Traditional macroscopic mechanical testing methods (such as tensile testing machines and hardness testers) are limited by testing resolution and observation capabilities, making it impossible to capture these microscopic dynamic responses and accurately characterize the intrinsic mechanical properties of materials.

[0003] To address this technological bottleneck, in-situ mechanical experimental devices based on scanning electron microscopy (SEM) have emerged. These devices combine a precise mechanical loading system with the high-resolution imaging capabilities of SEM, enabling real-time observation of the microstructural evolution of materials during mechanical loading. This achieves a direct correlation between "mechanical loading and microscopic response," providing core technological support for characterizing the micromechanical properties of materials. They have been widely applied in fields such as advanced materials research and development, and device failure analysis.

[0004] However, existing SEM in-situ mechanical experimental setups still have many technical shortcomings that urgently need to be addressed in practical applications, which severely restrict the testing accuracy and application scope: Poor compatibility of SEM sample chambers: SEM sample chambers are small and have strict requirements for non-magnetic and vacuum compatibility of the device. Most existing devices adopt a split design, which is bulky and difficult to integrate into the sample chamber. If integrated, they may interfere with the SEM imaging magnetic field, resulting in a decrease in imaging quality. Insufficient positioning and loading accuracy: Existing devices mostly adopt a single drive mode, with macro-motion positioning accuracy only reaching the 10μm level and micro-motion loading resolution limited to above 10nm. This cannot meet the dual requirements of "large stroke and rapid alignment, and precise loading at the nanoscale" in nano-indentation / scratch testing, and it is difficult to capture nanoscale dynamic behaviors such as dislocation movement and microcrack propagation. Moreover, the sample positioning of existing devices relies on manual adjustment, which is cumbersome and has a large positioning error.

[0005] In summary, developing an in-situ mechanical experimental device that is compact, highly precise, easy to operate, and adaptable to the SEM environment has become an urgent technical problem to be solved in this field. Utility Model Content

[0006] The purpose of this invention is to provide an in-situ mechanical experimental device for scanning electron microscopes to solve the problems existing in the prior art. It is compact, highly accurate, easy to operate, and suitable for the SEM environment.

[0007] To achieve the above objectives, this utility model provides the following solution: A scanning electron microscope in-situ mechanical experimental device, comprising: a base; a macro-motion coarse adjustment module, the macro-motion coarse adjustment module including a macro-motion drive component, a lead screw, a guide rail, and a transmission seat; the output end of the macro-motion drive component is connected to the lead screw via a transmission connection; the guide rail is disposed on the base, and the axis of the guide rail is parallel to the axis of the lead screw; the transmission seat is threadedly engaged with the lead screw, and the transmission seat is slidably connected to the guide rail via a worktable; a micro-motion fine adjustment module, the micro-motion fine adjustment module is disposed on the worktable, the micro-motion fine adjustment module including a first micro-drive component and a pressure head assembly, the pressure head assembly including a pressure head and a pressure head seat, the drive end of the first micro-drive component being connected to the pressure head seat; a sample micro-motion platform, the sample micro-motion platform including a second micro-drive component and a stage, the drive end of the second micro-drive component being connected to the stage, the stage having a sample bearing area, the sample bearing area being disposed opposite to the pressure head.

[0008] As one embodiment, the micro-motion fine-tuning module further includes a first flexible hinge, the first flexible hinge having a first movable part, and the driving end of the first micro-drive component being connected to the pressure head seat through the first movable part.

[0009] As one embodiment, the sample micro-motion platform is further provided with a second flexible hinge. The fixed end of the second flexible hinge is connected to the sample micro-motion platform, and the movable end of the second flexible hinge is provided with a second movable part. The second micro-drive component is connected to the stage through the second movable part.

[0010] In one embodiment, the macro-drive component is a stepper motor, and the output shaft of the stepper motor is connected to one end of the lead screw via a flexible coupling.

[0011] As one embodiment, a support seat is provided at the end of the lead screw away from the macro drive component. The bottom of the support seat is fixedly connected to the base. A bearing is provided on the support seat, and the inner ring of the bearing is connected to the shaft end of the lead screw.

[0012] In one embodiment, there are two guide rails, which are arranged parallel and symmetrically on the reference surface of the base along the axis of the lead screw.

[0013] In one embodiment, the bottom surface of the workbench is slidably connected to the guide rail via four sliders, and two sliders are provided on each guide rail.

[0014] As one embodiment, the base is provided with a support seat, the support seat includes two symmetrically arranged bosses and a groove located between the two bosses; the top surface of each boss is provided with the guide rail, the lead screw is disposed in the groove, and the lead screw is arranged along the axial direction of the groove.

[0015] In one embodiment, the base is fixedly provided with a first baffle and a second baffle at both ends along its length, and the first baffle and the second baffle are arranged parallel to each other; the sample micro-motion platform is disposed on the end face of the first baffle facing the support seat, and there is a first gap between the first baffle and the end of the support seat, and the edge portion of the stage is located in the first gap; there is a second gap between the second baffle and the end of the support seat, and the macro-motion drive is disposed in the second gap.

[0016] A method for operating a scanning electron microscope in-situ mechanical experimental apparatus, using the aforementioned scanning electron microscope in-situ mechanical experimental apparatus, includes the following steps: S1. Macro-motion coarse adjustment step: Control the macro-motion drive component to drive the lead screw to rotate, so that the transmission seat that is threaded with the lead screw drives the worktable to slide along the axis of the guide rail. The worktable drives the micro-motion fine adjustment module and the pressure head assembly to make macro-displacement along the Z direction, so that the pressure head assembly is initially close to the sample on the stage. S2, XY positioning steps: Control the second micro-drive component of the sample micro-motion platform to drive the stage to move along the X and / or Y directions, adjust the position of the sample, and align the sample with the indenter. S3. Fine-tuning loading step: Control the first micro-drive component of the fine-tuning module to move, and drive the indenter to make nanometer-level precise displacement along the Z direction through the elastic deformation of the first flexible hinge, so as to realize the in-situ mechanical loading of the indenter on the sample.

[0017] The present invention achieves the following technical advantages over the prior art: 1. This technical solution, through structural integration and precise drive design, integrates the macro coarse adjustment module, the micro fine adjustment module, and the sample micro-motion platform based on the mounting reference plane of the base. The overall structure is simplified and non-magnetic, adapting to the SEM vacuum environment and perfectly meeting the space limitations of the sample chamber. The macro coarse adjustment module adopts a transmission architecture of stepper motor, ball screw, and linear guide rail to achieve rapid positioning with a large stroke, quickly bringing the indenter and sample close to a micron-level distance. Then, the first flexible hinge driven by the piezoelectric stack achieves nanometer-level micro-motion loading. Combined with the precise XY-axis positioning of the sample micro-motion platform, it effectively solves the defects of low positioning accuracy and cumbersome operation of traditional devices, ensuring that the area to be tested is accurately aligned with the indenter.

[0018] Meanwhile, the indenter assembly works in conjunction with the macro-micro two-stage drive and the XY micro-motion platform to achieve in-situ mechanical testing of multiple modes such as indentation and scratching without replacing any parts, meeting the needs of multi-dimensional mechanical property characterization of advanced materials. During mechanical loading, SEM can observe the dynamic behavior of the sample such as micro-deformation and crack propagation in real time, directly establishing the correspondence between "mechanical load and micro-response". This solves the problem of the disconnect between loading data and observation data in traditional devices, effectively capturing the intrinsic mechanical behavior of materials at the nanoscale, and breaking through the technical bottleneck that traditional macro-tests cannot characterize micro-dynamic responses.

[0019] Other technical solutions of this utility model have also achieved the following technical effects: 2. The first movable part of the first flexible hinge and the second movable part of the second flexible hinge optimize the power transmission path through structural design, so that the driving force of the first and second micro-drive components is concentrated on the pressure head seat and the stage, reducing the dispersion and transmission loss of force, and significantly improving the linearity and repeatability of nanometer-level displacement output. The macro-drive component is connected to the lead screw drive through an elastic coupling, which can effectively compensate for the installation coaxiality error and reduce the impact of vibration on the transmission accuracy. The support seat and bearing combination at the other end of the lead screw enhances the radial stiffness of the lead screw, reduces the deflection deformation during high-speed rotation, and further reduces the macro-positioning error. With the coordinated control of the two-stage drive, a seamless connection from macro to micro is achieved, which greatly improves the overall testing accuracy.

[0020] 3. Two parallel and symmetrically arranged guide rails and four sliders on the bottom of the worktable form a four-point support structure, which not only improves the stability of the worktable movement but also enhances the load-bearing capacity of the device, avoiding test deviations caused by worktable tilting during loading. The integrated boss-groove design of the bearing seat arranges the guide rail and lead screw on the top surface of the boss and inside the groove, respectively, to achieve compact integration of the transmission components. With the gap distribution of the first and second baffles at both ends of the base, it provides reasonable installation space for the edge of the stage and the macro drive components, and also protects the components through the baffles to avoid collision damage. The overall structure maintains compactness while significantly improving rigidity, making it more suitable for the narrow space and vacuum non-magnetic environment of the SEM sample chamber, and the structural stability is stronger during long-term testing.

[0021] 4. The three-stage layered process of macro-motion coarse adjustment, XY positioning, and micro-motion fine adjustment in the working method is deeply integrated with the structural design of the device. The operation logic is clear, and the entire process from sample alignment to mechanical loading can be automated without complex manual intervention, greatly reducing the difficulty of operation. The symmetrical layout of dual guide rails and multiple sliders and the modular design of the bearing seat make the device easier to assemble and maintain. The uniform wear of moving parts, combined with the elastic deformation transmission of flexible hinges, reduces component wear and extends service life. At the same time, the structured transmission design and layered loading mode enable the device to maintain stable positioning accuracy and loading consistency in the testing of different types of samples, significantly improving test repeatability, reducing experimental errors, and providing more reliable data support for the characterization of the micromechanical properties of materials. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the overall structure of this utility model from another perspective; Figure 3 for Figure 2 A magnified view of a portion of point A in the middle; Figure 4 This is a schematic diagram of the structure of the present invention, omitting the micro-adjustment module; Figure 5 This is a schematic diagram of the structure of the present invention, omitting the micro-adjustment module and the worktable; Figure 6 This is a schematic diagram of the internal structure of this utility model; Figure 7 for Figure 6 A magnified view of a section at point B in the middle; Figure 8 This is a schematic diagram of the micro-adjustment module structure of this utility model; Figure 9 This is a schematic diagram of the lead screw structure of this utility model; Figure 10 Schematic diagrams of three types of flexible hinge pairs; Figure 11 This is a schematic diagram of the FEA calculation results for a right-angle flexible hinge; Figure 12 This is a schematic diagram of the FEA calculation results for a straight circular flexible hinge; Figure 13 This is a schematic diagram of the FEA calculation results for a V-shaped flexible hinge.

[0024] Among them, 1. base; 2. sample micro-motion platform; 3. stage; 4. Pressure head assembly; 401. Pressure head; 402. Pressure head base; 5. Macro drive unit; 6. Lead screw; 7. Guide rail; 8. Transmission base; 9. Worktable; 10. First flexible hinge; 1001. First moving part; 11. First micro-actuator; 12. Second micro-actuator; 13. Second flexible hinge; 1301. Second moving part; 14. Support seat; 15. Slider; 16. Boss; 17. Groove; 18. First baffle; 19. Second baffle; 20. Bearing seat; 21. Connecting crossbeam; 22. Connecting longitudinal arm; 23. Micro-motion seat. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] This embodiment provides an in-situ mechanical experimental setup for scanning electron microscopy. Please refer to [reference needed]. Figure 1-9As shown, the system includes a base 1, a macro-motion coarse adjustment module, a micro-motion fine adjustment module, a sample micro-motion platform 2, a stage 3, and a pressure head assembly 4. The upper surface of the base 1 is machined with a high-precision mounting reference surface to ensure the coaxiality of the macro-motion coarse adjustment module and the sample micro-motion platform 2. The macro-motion coarse adjustment module includes a macro-motion drive component 5, a lead screw 6, a guide rail 7, and a transmission seat 8. The output end of the macro-motion drive component 5 is coaxially connected to the lead screw 6, which can be a high-precision ball screw. The guide rail 7 is mounted on the base 1, and its axis is parallel to the axis of the lead screw 6. The transmission seat 8 is sleeved on the outside of the lead screw 6, and is threadedly connected to the lead screw 6. Preferably, the bottom of the transmission seat 8 is machined with threads matching the lead screw 6, forming a threaded pair when sleeved on the outside of the lead screw 6. The transmission seat 8 is slidably connected to the guide rail 7 via the worktable 9. The upper surface of the transmission seat 8 is rigidly connected to the worktable 9 via bolts. The micro-adjustment module is mounted on the worktable 9. The lower surface of the worktable 9 is slidably engaged with the guide rail 7 via the slider 15. The transmission seat 8 can rotate with the lead screw 6 and move stably along the axis of the guide rail 7, driving the worktable 9 and the micro-adjustment module above it to synchronously achieve coarse adjustment displacement. The micro-adjustment module includes a first flexible hinge 10 and a first micro-drive component 11. The drive end of the first micro-drive component 11 is connected to the first flexible hinge 10, and the movable end of the first flexible hinge 10 is connected to the pressure head assembly 4. Preferably, the drive end of the first micro-drive component 11 is connected to the pressure head assembly 4 via the movable end of the first flexible hinge 10. The first micro-drive component 11 can drive the first flexible hinge 10 to produce micro-deformation, driving the pressure head assembly 4 to move closer to or further away from the platform 3 via the movable end. The pressure head assembly 4 includes a pressure head 401 and a pressure head seat 402. The movable end of the first flexible hinge 10 is directly connected to the pressure head seat 402 of the pressure head assembly 4. Preferably, the movable end of the first flexible hinge 10 has a first movable part 1001. The driving end of the first micro-drive member 11 is connected to the pressure head seat 402 through the first movable part 1001.

[0028] The sample micro-motion platform 2 is mounted on the base 1. The sample micro-motion platform 2 is also an XY micro-motion platform, and its transmission direction corresponds to that of the macro coarse adjustment module. The sample micro-motion platform 2 is used to realize the micro-motion positioning of the stage 3 in the plane (X-axis and Y-axis directions) to ensure that the sample test area is accurately aligned with the pressure head 401. The sample micro-motion platform 2 includes a second micro-drive component 12 and a second flexible hinge 13. The fixed end of the second flexible hinge 13 is connected to the sample micro-motion platform 2, and the movable end of the second flexible hinge 13 is provided with a second movable part 1301. The second movable part 1301 is fixedly connected to the stage 3, that is, the second micro-drive component 12 is connected to the stage 3 through the second movable part 1301 of the second flexible hinge 13. The second micro-drive component 12 can drive the second flexible hinge 13 to produce micro-deformation, and drive the stage 3 to produce micro-motion displacement in the plane through the movable end of the second flexible hinge 13. The sample bearing area of ​​the stage 3 is positioned opposite to the indenter 401 of the indenter assembly 4, and the sample bearing area of ​​the stage 3 is used to mount the sample.

[0029] Work methods: S1. Device installation and positioning: Place the base 1 in the sample chamber of the scanning electron microscope (SEM). Utilize the high-precision mounting reference surface on the upper surface of the base 1 to ensure that the coaxiality of the macro-motion coarse adjustment module and the sample micro-motion platform 2 meets the requirements. Ensure that the center of the sample micro-motion platform 2 is collinear with the transmission direction of the macro-motion coarse adjustment module (i.e., the moving direction of the subsequent pressure head assembly 4), thus completing the fixation and initial positioning of the device within the SEM.

[0030] S2. Sample clamping: Place the sample to be subjected to in-situ mechanical testing in the sample bearing area of ​​the stage 3, ensuring that the sample is stably placed in the bearing area. The sample and the indenter 401 are positioned opposite each other to complete the clamping and fixing of the sample.

[0031] S3, Coarse Adjustment Approach of the Indenter: The lead screw 6 can be arranged along the Z-axis. The macro drive 5 of the macro coarse adjustment module is activated, and the output end of the macro drive 5 drives the lead screw 6 to rotate coaxially. Since the transmission seat 8 is sleeved on the outside of the lead screw 6 and forms a threaded pair with the lead screw 6, and the transmission seat 8 slides with the guide rail 7 through the worktable 9, the rotation of the lead screw 6 will drive the transmission seat 8 to move stably along the axis of the guide rail 7, enabling the transmission seat 8 to perform feed motion in the Z-axis direction. When the transmission seat 8 moves, it synchronously drives the worktable 9 and the fine adjustment module to move, which in turn drives the indenter assembly 4 on the fine adjustment module to move towards the stage 3, until the indenter 401 and the sample on the stage 3 are in the preset coarse adjustment approach state. Then, the macro drive 5 is turned off, and the coarse adjustment is stopped.

[0032] S4. Precise positioning of the sample: Start the sample micro-motion platform 2, and drive the second flexible hinge 13 to generate micro-deformation through the second micro-drive component 12; Since the movable end (second movable part 1301) of the second flexible hinge 13 is fixedly connected to the stage 3, the micro-deformation of the second flexible hinge 13 will cause the stage 3 to generate micro-displacement in the plane (X-axis and Y-axis directions); By adjusting the micro-displacement in the X-axis and Y-axis directions, the test area of ​​the sample on the stage 3 is precisely aligned with the indenter 401, and the precise positioning of the sample is completed.

[0033] S5. In-situ mechanical loading: The first micro-drive unit 11 of the micro-adjustment module is activated. The drive end of the first micro-drive unit 11 performs a Z-axis feed motion, and the drive end of the first micro-drive unit 11 drives the first flexible hinge 10 to produce controllable micro-deformation. Since the movable end (first movable part 1001) of the first flexible hinge 10 is connected to the indenter assembly 4, the micro-deformation of the first flexible hinge 10 will drive the indenter 401 of the indenter assembly 4 to move closer to the stage 3 through the movable end, so that the indenter 401 contacts the sample and applies a mechanical load, thereby realizing in-situ mechanical loading. If it is necessary to adjust the loading state or stop loading, the first flexible hinge 10 can be driven to deform in the opposite direction by the first micro-drive unit 11, which will drive the indenter 401 to move away from the stage 3, adjust the relative position of the indenter 401 and the sample, or release the load.

[0034] S6. Experimental observation: During the above-mentioned in-situ mechanical loading process, the mechanical response (such as deformation, damage, etc.) of the sample is observed in real time using a scanning electron microscope (SEM). After the experiment is completed, the first micro-drive 11 and the second micro-drive 12 are turned off in sequence. The macro-drive 5 drives the lead screw 6 to rotate in the opposite direction, which drives the pressure head 401 to move away from the stage 3 to the initial position. The sample is then removed, and the entire in-situ mechanical experiment is completed.

[0035] In one embodiment, the macro-drive component 5 is a stepper motor, and the output shaft of the stepper motor is connected to one end of the lead screw 6 via a flexible coupling. To accommodate the overall miniaturized design of the device and the limited installation space in the SEM sample chamber, the flexible coupling is preferably a miniature flexible coupling. The elastic deformation characteristics of the flexible coupling can absorb the instantaneous impact when the stepper motor starts or brakes, reducing the vibration transmitted to the lead screw 6, thereby reducing interference with positioning accuracy.

[0036] In one embodiment, the end of the lead screw 6 furthest from the macro-drive component 5 is positioned and supported by a support base 14. The bottom of the support base 14 is rigidly connected to the base 1, ensuring the stability of the support base 14 on the base 1. A bearing is embedded in the upper part of the support base 14, and the inner ring of the bearing is connected to the shaft end of the lead screw 6. Through the above structure, the side of the lead screw 6 furthest from the drive end is stably constrained by the support base 14, forming a "fixed at both ends" support mode in conjunction with the support structure at the end of the macro-drive component 5.

[0037] In one embodiment, there are two guide rails 7, which are arranged parallel and symmetrically along the axis of the lead screw 6 on the reference surface of the base 1. The bottom surface of the worktable 9 is slidably connected to the guide rails 7 via sliders 15. Preferably, the bottom surface of the worktable 9 is slidably connected to the guide rails 7 via four preload sliders 15, and each guide rail 7 is equipped with two sliders 15. The combination of two symmetrically arranged precision linear guide rails 7 and preload sliders 15 not only improves the stability of the movement of the worktable 9, but also effectively suppresses the sway and axial movement during the macro-motion coarse adjustment process.

[0038] In one embodiment, a support seat 20 is provided on the base 1. The cross-section of the support seat 20 is U-shaped. The support seat 20 specifically includes two symmetrical bosses 16 and a central groove 17. There is one boss 16 on each side, and the top surface of the boss 16 is used to install linear guide rails 7. Two preloaded sliders 15 are configured on the guide rails of each boss 16. The groove 17 is located between the two bosses 16 and can accommodate a screw drive structure. The screw drive structure specifically includes a screw 6, a macro drive component 5 (stepper motor), and a support seat 14. The screw 6 is arranged along the axial direction of the groove 17. One end is connected to the output shaft of the macro drive component 5 through a miniature elastic coupling, and the other end is fixed to the side wall of the groove of the base 1 through the support seat 14, forming a "fixed at both ends" support mode. The worktable 9 serves as the connecting carrier between the macro coarse adjustment module and the micro fine adjustment module. The bottom is rigidly connected to the slider 15, and the top is used to install the Z-axis micro transmission mechanism. When the macro-drive component 5 drives the lead screw 6 to rotate, the worktable 9 moves smoothly along the axial direction of the linear guide rail 7 with the slider 15, achieving micron-level coarse positioning between the pressure head 401 and the stage 3. The lead screw drive structure can be hidden within the groove 17, making the guide rail layout on the top surface of the boss 16 simpler. Furthermore, the rigid structure of the boss 16 protects the lead screw drive area, reducing external vibration and magnetic field interference, while also providing a structural basis for adapting to the compact space of the SEM sample chamber.

[0039] In one embodiment, a first baffle 18 and a second baffle 19 are fixedly installed at both ends of the base 1 along its length, respectively, arranged in parallel and perpendicular to the top surface of the base 1. The sample micro-motion platform 2 is located on the side of the first baffle 18 facing the support 20. A first gap is formed between the first baffle 18 and the end of the support 20 near the first baffle 18, and the edge of the stage 3 is located within this first gap. This gap is designed to provide clearance for the stage 3 to make micro-motions with the sample micro-motion platform 2, preventing motion interference between the stage 3 and the support 20. A second gap is formed between the second baffle 19 and the end of the support 20 near the second baffle 19. The macro-motion drive 5 (stepper motor) is installed within this second gap via a motor bracket, and the output shaft axis of the macro-motion drive 5 is coaxial with the axis of the lead screw 6. This gap design not only provides space for the installation of the macro-motion drive 5 but also provides lateral protection for the macro-motion drive 5 through the second baffle 19. Through the structural design of "two-end baffles and gap avoidance", the sample micro-motion platform 2, bearing seat 20, lead screw 6 and macro-motion drive 5 are arranged linearly on the base 1, which is adapted to the axial space limitation of the SEM sample chamber.

[0040] In one embodiment, both the first flexible hinge 10 and the second flexible hinge 13 include right-angle flexible hinge structures. Each right-angle flexible hinge structure includes a connecting beam 21 and a connecting longitudinal arm 22. Both the connecting beam 21 and the connecting longitudinal arm 22 are flexible structures with elastic deformation capabilities. The connecting beam 21 is a strip-shaped flexible arm, and the connecting longitudinal arm 22 is a strip-shaped flexible beam. Adjacent connecting longitudinal arms 22 are distributed in parallel at intervals and are connected by the connecting beam 21. The axis of the connecting beam 21 is perpendicular to the axis of the connecting longitudinal arm 22. When the piezoelectric stack outputs driving force, the connecting longitudinal arm 22 undergoes bending deformation, and the connecting beam 21 coordinates the displacement synchronization of adjacent connecting longitudinal arms 22 through its own elastic deformation.

[0041] In one embodiment, the micro-motion fine-tuning module uses the worktable 9 as the macroscopic displacement connection basis and the micro-motion seat 23 as the nanometer-level fine-tuning core carrier, integrating components such as the right-angled first flexible hinge 10 and the piezoelectric stack (first micro-drive component 11) to achieve precise loading of the pressure head assembly 4 along the Z-axis. The worktable 9 is rectangular and flat. Its bottom is rigidly connected to the transmission seat 8 of the macro-motion coarse-tuning module by bolts, and the two sides of the worktable 9 are fixed to the pre-loaded slider 15 on the guide rail 7. When the macro-motion drive component 5 (stepper motor) drives the lead screw 6 to rotate, the worktable 9 performs micrometer-level coarse-tuning movement along the Z-axis of the guide rail 7 with the slider 15, serving as the "macroscopic displacement bearing basis" of the micro-motion fine-tuning module and ensuring rapid alignment of the initial position of the pressure head assembly 4 with the stage 3. The micro-motion seat 23 has a rectangular structure and is directly fixed to the center area of ​​the top surface of the worktable 9 by screws. As the "fine-tuning core carrier," the micro-motion seat 23 has bolt holes at its ends for connecting the fixed end of the first flexible hinge 10. The first flexible hinge 10 is a right-angle flexible hinge structure. The fixed end of the first flexible hinge 10 is fixedly connected to the end of the micro-motion seat 23, and the movable end of the first flexible hinge 10 is welded to the mounting base of the pressure head assembly 4. Its connecting crossbeam 21 and connecting longitudinal arm 22 are arranged in a vertical array. When the first micro-drive component 11 outputs driving force, the connecting longitudinal arm 22 bends and deforms along the Z direction. The connecting crossbeam 21 coordinates the displacement synchronization of adjacent connecting longitudinal arms 22 through its own elastic deformation, thereby driving the pressure head assembly 4 to achieve fine adjustment in the Z direction. This structure, through the hierarchical design of "worktable 9 bearing macro coarse adjustment → micro-motion seat 23 connecting fine adjustment transmission → first flexible hinge 10 achieving nanometer-level displacement", ensures compatibility with the SEM non-magnetic environment while realizing "micron-level coarse adjustment coverage and nanometer-level fine adjustment control" of the pressure head assembly 4 in the Z direction, meeting the dual requirements of "large stroke positioning and high-precision loading" in in-situ mechanical testing.

[0042] In this embodiment, the micro-motion seat 23 has a rectangular block structure with a mounting groove reserved in the middle along the Z direction. The first micro-drive element 11 is a piezoelectric stack, with its main body embedded in the mounting groove and its end protruding from the top surface of the micro-motion seat 23. The axis of the first micro-drive element 11 is parallel to the Z-axis of the micro-motion seat 23 and coaxial with the central axis of the pressure head assembly 4, ensuring that the driving force is transmitted without bias along the Z direction. The pressure head assembly 4 includes a pressure head 401 and a pressure head seat 402: the pressure head seat 402 has a rectangular block structure, with its bottom end face directly abutting against the protruding end of the first micro-drive element 11, and its top rigidly connected to the pressure head 401; the pressure head 401 is made of diamond material and is used to directly contact the sample surface to apply load. Two first flexible hinges 10 are symmetrically arranged on both sides of the pressure head seat 402. Each hinge is a right-angle flexible hinge, and the movable ends of the two first flexible hinges 10 are connected to the first movable part 1001. The fixed ends of the first flexible hinges 10 are rigidly connected to the side wall of the micro-motion seat 23, and the movable ends of the first flexible hinges 10 are fixedly connected to the side wall of the pressure head seat 402. The connecting beams 21 and connecting arms 22 of the first flexible hinges 10 are arranged in a vertical array. Both the connecting beams 21 and connecting arms 22 are flexible structures, and displacement is transmitted through elastic deformation.

[0043] When the first micro-actuator 11 (piezoelectric stack) is energized, it undergoes expansion and contraction along the Z-direction, driving the pressure head seat 402 to move synchronously through its end contact. At this time, the connecting longitudinal arms 22 of the first flexible hinges 10 on both sides bend and deform along the Z-direction, and the connecting crossbeam 21 coordinates the displacement synchronization of the hinges on both sides through its own elastic deformation, ultimately driving the pressure head assembly 4 to achieve Z-direction fine adjustment. The symmetrical layout of the double flexible hinges can counteract the off-center load moment of the pressure head assembly 4, making the loading direction perpendicular to the sample surface. Preferably, the outermost connecting crossbeam 21 is fixedly connected to the side wall of the micro-motion seat 23 through the connecting seat 24, and the innermost connecting crossbeam 21 is directly fixedly connected to the side wall of the first movable part 1001 as the movable end. The two ends of the connecting longitudinal arm 22 in the middle are rigidly fixedly connected to the adjacent connecting crossbeam 21 respectively. The connecting beam 21 and the connecting longitudinal arm 22 are spaced apart from the micro-motion seat 23, providing sufficient space for the elastic deformation of the connecting beam 21 and the connecting longitudinal arm 22 under the driving force of the first micro-drive component 11. This ensures that the two can achieve precise displacement through their own micro-bending, while avoiding mechanical interference with the micro-motion seat 23 and ensuring smooth movement.

[0044] In one embodiment, the lead screw 6 of the macro-motion coarse adjustment module is arranged along the Z-axis of the device (perpendicular to the surface of the stage 3). When the macro-motion drive 5 drives the lead screw 6 to rotate, the nut pair converts the rotational motion into linear motion, driving the worktable 9 and the micro-motion fine adjustment module to make macroscopic displacement along the Z-axis, achieving preliminary alignment of the indenter 401 with the sample. The first micro-drive 11 is a Z-axis piezoelectric stack, extending along the Z-axis. The Z-axis expansion and contraction that this piezoelectric stack can generate under the driving voltage, through the coordinated deformation of the first flexible hinge 10, drives the indenter 401 to make nanoscale feed motion along the Z-axis.

[0045] The second micro-actuator 12 is integrated into the sample micro-motion platform 2, comprising two mutually perpendicular piezoelectric stacks. The X-axis second micro-actuator is arranged along the X-axis, which is parallel to the transverse direction of the stage 3 surface. Its fixed end is bolted to the side wall of the sample micro-motion platform 2, and its telescopic end abuts against the X-axis flexible hinge group of the stage 3. The Y-axis second micro-actuator is arranged along the Y-axis, which is parallel to the longitudinal direction of the stage 3 surface. The fixed end of the Y-axis second micro-actuator is fixed to the front wall of the sample micro-motion platform 2, and its telescopic end abuts against the Y-axis flexible hinge group of the stage 3. Both the X-axis and Y-axis flexible hinge groups are right-angle hinges, and their structures are the same as the first flexible hinge 10. The X-axis / Y-axis telescopic amounts generated by the two second micro-actuators 12 under voltage drive the stage 3 to move independently along the X and Y axes through the elastic deformation of the corresponding flexible hinges. It adopts a hierarchical driving logic of "Z-axis macro coarse adjustment, Z-axis fine adjustment, and XY-axis fine adjustment", which not only achieves large stroke alignment through lead screw 6, but also achieves nanometer-level precision control through piezoelectric stack, meeting the dual requirements of "rapid approach and accurate loading" in SEM in-situ testing.

[0046] In this embodiment, the present invention adopts a two-stage positioning and transmission architecture of "macro-coarse adjustment - micro-fine adjustment" to meet the requirements of "large stroke rapid alignment and nanometer-level precision loading" for in-situ mechanical testing of scanning electron microscopes (SEM). The specific structure and function are as follows: Macro-motion coarse adjustment module: The macro-motion coarse adjustment module is mounted on base 1 and includes macro-motion drive 5 (stepper motor), lead screw 6 (precision ball screw), guide rail 7 (linear guide rail), and transmission seat 8. The transmission seat 8 is threadedly engaged with the lead screw 6 and slidably connected to the guide rail 7 via slider 15. The top of the transmission seat 8 is rigidly fixed to the worktable 9. When the device is started, the macro-motion drive 5 drives the lead screw 6 to rotate, and the transmission seat 8 moves smoothly along the Z-axis of the guide rail 7 (perpendicular to the surface of the stage 3) via slider 15, driving the worktable 9 and the Z-axis micro-motion fine adjustment module (including micro-motion seat 23, first micro-drive 11, etc.) fixed on it to move synchronously, realizing the rapid approach of the pressure head 401 and the sample on the stage 3 until the distance between them is reduced to the micrometer level.

[0047] Z-axis micro-adjustment module: The Z-axis micro-adjustment module is integrated on the top surface of the worktable 9 and includes a micro-adjustment base 23, a first micro-drive component 11 (piezoelectric stack), and a first flexible hinge 10. The first micro-drive component 11 is embedded in the mounting groove of the micro-adjustment base 23, and its telescopic end abuts against the indenter seat 402. The two sides of the indenter seat 402 are connected to the micro-adjustment base 23 via the first flexible hinge 10, and the top is rigidly connected to the indenter 401. When the macro-adjustment is completed, the first micro-drive component 11 is energized to generate Z-axis telescopic movement, which drives the indenter 401 to make nanometer-level precise displacement along the Z-axis through the elastic deformation of the first flexible hinge 10, realizing indentation testing on the sample surface.

[0048] The sample micro-motion platform 2 (XY micro-motion platform) is mounted on the base 1, and the sample stage 3 is fixed to the sample micro-motion platform 2 with screws made of non-magnetic pure titanium alloy. When the scratch test is performed, the second micro-drive component 12 in the X direction drives the stage 3 to move slightly in the X direction through the deformation of the second flexible hinge 13, and the second micro-drive component 12 in the Y direction achieves the same slight movement in the Y direction. With the constant load of the Z-direction indenter 401, the XY-direction movement of the stage 3 can cause the sample to slide relative to the indenter 401, thus completing the surface scratch test.

[0049] In one embodiment, the design of the micro-transmission mechanism, with the indenter 401 serving as the core actuator, directly determines the accuracy and reliability of SEM in-situ mechanical testing (indentation, scratch) through the selection of its material and geometry. ① Material selection In nano-indentation / scratch testing, the material of indenter 401 needs to meet the requirements of "high hardness and high elastic modulus". Then, depending on the usage environment, the commonly used indenter materials can be divided into two categories: at room temperature, diamond indenters are usually used; since diamond will turn into stone desert at high temperature, sapphire or boron carbide are usually used in high temperature environments.

[0050] ② Selection of pressure head Depending on the geometry of the tip, common types of nanoindenters include the Bodeich indenter, the round-headed conical indenter, and the filament indenter.

[0051] The Glass indenter is suitable for bulk materials or thin films thicker than 100 nm. It allows materials to undergo easy plastic deformation, and is therefore primarily used to characterize the hardness (Marsh hardness and indentation hardness) and modulus (indentation modulus) of materials. This indenter is also a common indenter used in instrumented indentation testing as required by testing standards. Compared to the Glass indenter, the cubic indenter has a sharper tip, making it more suitable for ultra-thin samples where plastic deformation must be limited to a small volume. Conical and spherical tips are widely used for indentation of soft polymers and MEMS structures. These indenters are also commonly used for scratch testing and friction / wear testing.

[0052] In summary, this design selects a round-headed conical diamond indenter, i.e., indenter 401 includes a conical head with a rounded end, which can avoid the tip directly crushing the sample. At the same time, the load is transferred through the contact between the rounded end and the sample, making it suitable for in-situ mechanical experimental scenarios such as micro-indentation and elastic modulus testing.

[0053] In one embodiment, regarding the integration scheme, this utility model adopts a two-stage drive scheme of macro-motion and micro-motion: ① Macro-motion coarse adjustment module: stepper motor, ball screw, linear guide rail. This module can achieve rapid positioning with a large stroke of ≥50mm, quickly bringing the pressure head 401 and the sample on the stage 3 close to the micron-level distance, greatly shortening the test preparation time.

[0054] ② Micro-motion fine-tuning module: piezoelectric stack drive and flexible hinge amplification mechanism, directly outputting nanometer-level precision displacement. After the macro-motion coarse adjustment is in place, the precise expansion and contraction of the piezoelectric stack and the coordinated deformation of the flexible hinge drive the indenter 401 to complete the Z-axis nanometer-level loading, meeting the high-precision force-displacement control requirements of indentation and scratch testing.

[0055] Integrated observation module: Adapted to the SEM sample chamber, it monitors the test area in real time through optical / electron imaging. The module relies on the SEM's own electron imaging system to perform real-time imaging of the test area through electron beam scanning of the SEM, and simultaneously records the contact state between the indenter 401 and the sample, microscopic deformation, and surface morphology changes.

[0056] In one embodiment, the sample fixing method is as follows: the sample to be tested is pre-attached to the surface of the working sheet, and then the working sheet containing the sample is fixed to the stage 3 with conductive tape.

[0057] In one embodiment, the macro-motion coarse adjustment mechanism: ① Stepper motor selection Model: PKP543N18A, Step angle: 0.72°, Maximum torque: 0.22N・m.

[0058] Driving method: Microstepping circuit achieves 5000 pulses / revolution, resolution ≤0.2μm.

[0059] Table 1. Basic Performance Table of PKP543N18A

[0060] By checking the speed-torque characteristic diagram of PKP543N18A, it can be seen that the operating speed and the operating range indicated by the necessary torque in this design are within the curve, therefore this model of motor can be used. Furthermore, the inertia ratio is 2.708103, which is much less than 30, further demonstrating that selecting this model of motor is safe and reliable.

[0061] ② Ball screw shaft design and selection Specifications: THK MDK-6mm, lead 1mm, support method: fixed support at both ends; preload 0.1kN.

[0062] Verification calculation: Axial stiffness: ≥30N / μm (meets positioning accuracy requirements). Effectively ensures the alignment stability between the indenter 401 and the sample.

[0063] Service life: >30,000 hours (based on equivalent load Lh=1.837×10⁻⁶) 7 km).

[0064] A schematic diagram of a two-section fixed-type ball screw is shown below. Figure 9 As shown.

[0065] In one embodiment, the micro-adjustment mechanism is: ① Piezoelectric stack drive The core drive unit of the micro-motion fine-tuning mechanism adopts a NanoMotions PZ150 / 5×2 / 20 piezoelectric stack, with a displacement range of 20-28μm and a resolution ≤1nm. Preload: A preload of 15MPa is applied to the thread to eliminate hysteresis.

[0066] Table 2. Basic performance of PZ 150 / 5×2 / 20 piezoelectric stack

[0067] ② Flexible Hinge Amplification Mechanism: The design of the flexible hinge includes the analysis and design of the flexible hinge pair, the amplification mechanism, and the guiding mechanism. Before designing these three main structural parts, materials are selected based on the working environment required by this design.

[0068] Material selection: Table 3 Common Flexible Hinge Materials

[0069] σ in the table s E represents the strength of the material; E represents the elastic modulus of the material.

[0070] The maximum deformation of a flexible hinge is not only related to the structural dimensions, but also closely related to the material parameters. When σ s When / E is at its maximum, the hinge has the greatest reliable deformation capacity. This ratio directly reflects the material's reliable deformation potential during the elastic deformation stage.

[0071] Therefore, according to Table 3, aluminum 075 and steel 4140 have relatively high ratios of strength to elastic modulus, indicating that they have greater reliable deformation potential in the elastic deformation stage and are more suitable for the micro-deformation transmission requirements of flexible hinges. Since the nano-indentation / scratch tester in this design is integrated into the SEM, the materials required for the flexible hinges need to be non-magnetic, and aluminum has very low magnetic permeability and is therefore a non-magnetic material.

[0072] In summary, aluminum 7075 was chosen as the material for the flexible hinge because it possesses excellent mechanical deformation potential and can meet the non-magnetic environment requirements of SEM.

[0073] In this embodiment, the selection of the flexible hinge type is as follows: This embodiment is based on the core requirements of micro-drive mechanisms for in-situ SEM testing (balancing large deformation, stress safety, and structural compactness), and uses finite element analysis to select the optimal flexible hinge type. According to flexible hinge design theory, common flexible hinge types can be divided into right-angle, straight-circular, and V-type. To verify the adaptability of different types, the commercial finite element software ABAQUS was used to model, calculate, and analyze three typical flexible hinges, and the micro-drive mechanism most suitable for integration into an in-situ testing unit within an SEM was selected.

[0074] According to the knowledge of elasticity mechanics and related literature, when designing flexible hinges and analyzing the stress inside them, the model can usually be simplified to a rigid physical model with one end fixed and the other end free. Accordingly, in the subsequent finite element calculation of the flexible hinge pair, the boundary conditions are all set to the form of one end being completely fixed and the other end being free.

[0075] Table 4 Dimensions of Three Types of Flexible Hinge Pairs

[0076] Where L, w, b, and t are references Figure 10 As shown.

[0077] In Figure 10 In the diagram, (a) is a straight circle; (b) is a right angle; and (c) is a V-shape.

[0078] Based on this, the calculation of three types of flexible hinges is performed in ABAQUS, and the modeling process is as follows: A. Material Setup Table 5. Parameter settings for flexible hinge pair materials

[0079] B. Boundary conditions: The left end of the flexible hinge is fully fixed; a load of 10N is applied to the vertical surface of the rigid arm at the right end; C. Seed density: Seed size is 0.1 mm; D. Calculation results a) Right-angle type: As shown in Table 6, the maximum stress is 134 MPa; the maximum displacement is 63.38 μm; Please refer to the schematic diagram of the FEA calculation results for the right-angle flexible hinge. Figure 11 As shown.

[0080] b) Straight-circular type: As shown in Table 6, the maximum stress is 87.36 MPa; the maximum displacement is 23.15 μm; Please refer to the schematic diagram of the FEA calculation results for the straight circular flexible hinge. Figure 12 As shown.

[0081] c) V-type: As shown in Table 6, the maximum stress is 64.79 MPa; the maximum displacement is 11.37 μm; Please refer to the schematic diagram of the FEA calculation results for the V-shaped flexible hinge. Figure 13 As shown.

[0082] E. Results Analysis Table 6 Comparison of FEA calculation results for three types of flexible hinge pairs

[0083] The maximum displacement of the right-angle flexible hinge (63.38 μm) is significantly higher than that of the circular (23.15 μm) and V-type (11.37 μm), exhibiting optimal flexibility. It can output greater deformation under the same driving load, matching the drive stroke of the piezoelectric stack and ensuring that the Z-axis fine-tuning range of the indenter 401 covers the testing requirements. The right-angle hinge has a compact structure and simple manufacturing process. Its vertical array layout (connecting beam 21 perpendicular to connecting longitudinal arm 22) reduces space occupation, adapting to the confined environment of the SEM sample chamber, and facilitating integration with the micro-motion seat 23 and indenter seat 402. The maximum stress of all three flexible hinges is less than the allowable stress of Al7075 (503 MPa), while the right-angle flexible hinge has the largest maximum displacement, indicating the greatest flexibility. It can achieve the maximum displacement output value while ensuring safety and reliability. Therefore, this design selects the right-angle flexible hinge pair.

[0084] In one embodiment, control and signal processing: ① Drive control: Macro-motion uses PID algorithm to control stepper motors, while micro-motion uses voltage-displacement linear control of piezoelectric stack.

[0085] ② Feedback system An incremental photoelectric encoder can be integrated at the end of the lead screw 6. The photoelectric encoder (1μm resolution) detects the macro position, and the piezoelectric ceramic displacement sensor (1nm resolution) provides feedback on the micro displacement. Specifically, the Z-direction displacement of the worktable 9 can be calculated by collecting the rotation angle of the lead screw 6.

[0086] ④ Data synchronization It works in conjunction with the SEM image acquisition system to achieve real-time synchronous storage of displacement-load-morphology data.

[0087] This invention can achieve the following beneficial effects: (1) Real-time capture of nanoscale deformation: Relying on the 1~10nm nanoscale resolution of SEM, the micro-dynamic behaviors such as dislocation movement, crack initiation and propagation, and interface peeling during the indentation / scratching process are directly observed, providing intuitive experimental evidence for revealing the essential mechanism of material failure.

[0088] (2) High precision and high resolution: The piezoelectric stacking drives the flexible hinge, achieving a displacement resolution of nanometer level (50nm) and a maximum output force of 1.5N, effectively ensuring nanometer-level loading control precision. The use of right-angle flexible hinges and bridge amplification mechanism reduces cross-coupling errors and improves control stability.

[0089] (3) Miniaturization and integration: The overall size is only 200mm×100mm×78mm. It adopts a modular and compact layout and can be integrated into the SEM sample chamber to meet the space constraints. The macro-micro two-level drive architecture (stepper motor, precision ball screw, piezoelectric stack) achieves a seamless connection between rapid coarse adjustment with a large stroke of ≥50mm and nanometer-level precision positioning, which greatly shortens the test preparation time.

[0090] (4) Non-magnetic and environmentally resistant design: Key components (worktable 9, micro-motion seat 23, stage 3, etc.) are made of non-magnetic materials such as titanium alloy and aluminum alloy to avoid interfering with the magnetic field of SEM electronic imaging and to adapt to the SEM vacuum environment; fasteners adopt anti-loosening structure design, and the transmission system optimizes the anti-vibration performance to ensure long-term stability.

[0091] (5) Modularity and scalability: The XY micro-motion platform supports parallel or series structure expansion, which can flexibly adapt to the multi-axis linkage test requirements; at the same time, it is compatible with different types of samples and multi-mode tests, and can expand the application scenarios without major modifications, making it suitable for complex multi-axis test requirements.

[0092] Working method of in-situ mechanical experimental setup using scanning electron microscope. Step 1: Device Installation and Initialization Adaptation: Place the base 1 stably inside the sample chamber of the scanning electron microscope (SEM). Using the high-precision mounting reference surface on the upper surface of the base 1, calibrate the coaxiality of the macro-motion coarse adjustment module and the sample micro-motion platform 2, ensuring that the center of the sample micro-motion platform 2 is collinear with the Z-axis transmission direction of the macro-motion coarse adjustment module. Utilizing the gap design formed by the first baffle 18 and the second baffle 19 at both ends of the base 1, the edge of the stage 3 and the macro-motion drive component 5 (stepper motor) are respectively adapted to the first and second gaps, avoiding motion interference. Simultaneously, the "U-shaped" structure of the support 20 allows for the compact integration of transmission components such as the lead screw 6 and guide rail 7, adapting to the confined space and vacuum-free environment of the SEM sample chamber, completing the fixation and initial positioning of the device within the SEM.

[0093] Step 2: Sample clamping and positioning: Place the sample to be tested in the sample bearing area of ​​the stage 3, ensuring that the sample is stably fixed and positioned opposite the indenter 401. The non-magnetic pure titanium alloy screws prevent magnetic interference during sample clamping, while ensuring the sample surface is flat and the area to be tested faces the indenter 401, thus completing the sample clamping preparation.

[0094] Step 3: Macro-motion coarse adjustment and rapid approach: Start the macro-motion drive unit 5 (stepper motor), whose output shaft drives the lead screw 6 to rotate through a miniature flexible coupling. Since the lead screw 6 adopts a "fixed at both ends" support mode, one end of the lead screw 6 is connected to the motor through the flexible coupling, and the other end is positioned by the bearing of the support seat 14. The transmission seat 8 and the lead screw 6 form a threaded pair. At the same time, the worktable 9 slides with two parallel and symmetrical guide rails 7 through four pre-loaded sliders 15. The rotation of the lead screw 6 is converted into a smooth linear motion of the transmission seat 8 along the Z direction, which drives the worktable 9 and the micro-motion fine adjustment module above it to move synchronously, so that the pressure head 401 rapidly approaches the sample until the distance between the pressure head and the sample is reduced to the micron-level preset range. Then, turn off the macro-motion drive unit 5 and stop the coarse adjustment.

[0095] Step 4: Precise Alignment in the XY Direction: Activate the sample micro-motion platform 2 (XY micro-motion platform) and control the movement of the two mutually perpendicular second micro-actuators (piezoelectric stacks) integrated therein: The X-axis second micro-actuator drives the stage 3 to move slightly in the X direction through the elastic deformation of the X-axis right-angled second flexible hinge 13; similarly, the Y-axis second micro-actuator drives the stage 3 to move slightly in the Y direction through the Y-axis second flexible hinge 13. The connecting beam 21 and connecting longitudinal arm 22 of the second flexible hinge 13 are arranged in a vertical array, and the elastic deformation coordinates the displacement synchronization to ensure the smooth movement of the stage 3, precisely adjusting the relative position of the sample testing area and the indenter 401, completing nanometer-level precise alignment.

[0096] Step 5: Fine-tuning the mechanical loading Indentation test: The first micro-actuator 11 (piezoelectric stack) is activated. It is embedded in the mounting groove of the micro-actuator 23 and undergoes expansion and contraction deformation along the Z-direction. The driving force is transmitted through the contact between its end and the indenter seat 402. The right-angled first flexible hinges 10 symmetrically arranged on both sides of the indenter seat 402 undergo elastic deformation simultaneously to counteract the off-center load torque, driving the indenter 401 to make nanometer-level precise feed along the Z-direction, contacting the sample surface and applying a controllable mechanical load to achieve in-situ indentation test.

[0097] Scratch test: Maintain a constant load output by the first micro-drive 11 so that the indenter 401 is in continuous contact with the sample surface; at the same time, control the second micro-drive in the XY direction to move in coordination, drive the stage 3 to move smoothly in the X or Y direction, and cause the sample to slide relative to the indenter 401 to complete the surface scratch test.

[0098] Step 6: Real-time observation and device reset: Throughout the mechanical loading process, the microscopic dynamic response of the sample is observed and recorded in real time using SEM, including microscopic dynamic responses such as deformation, crack initiation and propagation, and interface delamination. After the experiment, the first micro-drive component 11 is controlled to extend and retract in the reverse direction, driving the pressure head 401 to move away from the sample via the first flexible hinge 10, thus relieving the load; then the second micro-drive component is turned off to stop the micro-motion in the XY direction; finally, the macro-drive component 5 is started to rotate in the reverse direction, driving the worktable 9 and the micro-motion fine-tuning module to reset to the initial position, opening the SEM loading cavity, removing the sample, and completing the entire in-situ mechanical experiment.

[0099] It should be noted that, for those skilled in the art, it is obvious that this utility model is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this utility model is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0100] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A scanning electron microscope in-situ mechanical experimental apparatus, characterized in that, include: Base (1); The macro-motion coarse adjustment module includes a macro-motion drive component (5), a lead screw (6), a guide rail (7), and a transmission seat (8); the output end of the macro-motion drive component (5) is connected to the lead screw (6) for transmission; the guide rail (7) is set on the base (1), and the axis of the guide rail (7) is parallel to the axis of the lead screw (6); the transmission seat (8) is threadedly engaged with the lead screw (6), and the transmission seat (8) is slidably connected to the guide rail (7) through a worktable (9); The micro-motion fine adjustment module is located on the worktable (9). The micro-motion fine adjustment module includes a first micro-drive component (11) and a pressure head assembly (4). The pressure head assembly (4) includes a pressure head (401) and a pressure head seat (402). The drive end of the first micro-drive component (11) is connected to the pressure head seat (402). The sample micro-motion platform (2) includes a second micro-drive (12) and a stage (3). The drive end of the second micro-drive (12) is connected to the stage (3). The stage (3) has a sample bearing area, which is arranged opposite to the pressure head (401).

2. The scanning electron microscope in-situ mechanical experimental apparatus according to claim 1, characterized in that, The micro-motion fine-tuning module also includes a first flexible hinge (10), which has a first movable part (1001). The driving end of the first micro-drive (11) is connected to the pressure head seat (402) through the first movable part (1001).

3. The scanning electron microscope in-situ mechanical experimental apparatus according to claim 1, characterized in that, The sample micro-motion platform (2) is also provided with a second flexible hinge (13). The fixed end of the second flexible hinge (13) is connected to the sample micro-motion platform (2). The movable end of the second flexible hinge (13) is provided with a second movable part (1301). The second micro-drive component (12) is connected to the stage (3) through the second movable part (1301).

4. The scanning electron microscope in-situ mechanical experimental apparatus according to claim 1, characterized in that, The macro drive component (5) is a stepper motor, and the output shaft of the stepper motor is connected to one end of the lead screw (6) via a flexible coupling.

5. The scanning electron microscope in-situ mechanical experimental apparatus according to claim 1, characterized in that, A support base (14) is provided at one end of the lead screw (6) away from the macro drive component (5). The bottom of the support base (14) is fixedly connected to the base (1). A bearing is provided on the support base (14), and the inner ring of the bearing is connected to the shaft end of the lead screw (6).

6. The in-situ mechanical experimental apparatus for scanning electron microscopy according to claim 1, characterized in that, The number of guide rails (7) is two, and the two guide rails (7) are arranged parallel and symmetrically along the axis of the lead screw (6) on the reference surface of the base (1).

7. The scanning electron microscope in-situ mechanical experimental apparatus according to claim 6, characterized in that, The bottom surface of the workbench (9) is slidably connected to the guide rail (7) by four sliders (15), and two sliders (15) are provided on each guide rail (7).

8. The in-situ mechanical experimental apparatus for scanning electron microscopy according to claim 6, characterized in that, The base (1) is provided with a support seat (20), which includes two symmetrically arranged bosses (16) and a groove (17) located between the two bosses (16); the top surface of each boss (16) is provided with a guide rail (7), the lead screw (6) is arranged in the groove (17), and the lead screw (6) is arranged along the axial direction of the groove (17).

9. The in-situ mechanical experimental apparatus for scanning electron microscopy according to claim 8, characterized in that, The base (1) is fixed with a first baffle (18) and a second baffle (19) at both ends along its length, with the first baffle (18) and the second baffle (19) arranged parallel to each other; the sample micro-motion platform (2) is set on the side end face of the first baffle (18) facing the support seat (20), with a first gap between the first baffle (18) and the end of the support seat (20), and the edge part of the stage (3) is located in the first gap; the second baffle (19) and the end of the support seat (20) have a second gap, and the macro-motion drive (5) is set in the second gap.

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