Integrated probe stepping and scanning assembly and stepping scanning method for scanning probe microscope

Abstract

This invention relates to the field of probe scanning technology, specifically to an integrated probe stepping scanning assembly and method for a scanning probe microscope. The invention includes a frame and a piezoelectric tube with its fixed outer edge fixed to the frame. At least three partition slits are arranged along the axial direction on the outer surface of the piezoelectric tube to divide it into at least three electrode partitions. Decoupling slits penetrating the inside and outside of the piezoelectric tube are also correspondingly arranged at the partition slits of adjacent electrode partitions. The starting point of each decoupling slit is located at the free end of the piezoelectric tube, and all decoupling slits are of equal length and shorter than the length of the partition slits. An elastic body is arranged on the inner side of the piezoelectric tube, elastically abutting against each electrode partition. The sliding friction between any electrode partition and the elastic body is less than the sum of the static frictions between other electrode partitions and the elastic body. A probe assembly is installed on the elastic body near the fixed end of the piezoelectric tube. This invention integrates traditional coarse approximation and fine scanning functions into a single piezoelectric element, thereby simplifying the system structure and improving performance.

Description

Technical Field

[0001] This invention relates to the field of probe scanning technology, specifically to an integrated probe stepping scanning component and stepping scanning method for a scanning probe microscope. Background Technology

[0002] Scanning probe microscopy is a key tool for characterizing surface morphology and properties at the nanoscale and even atomic scale. Its working principle involves scanning the sample surface with an extremely sharp probe, reconstructing surface information by detecting signals such as the interaction force or tunneling current between the probe tip and the sample.

[0003] Traditional scanning probe microscope systems generally employ a hierarchical drive structure to achieve probe positioning and scanning. Specifically, they typically include two independent actuators:

[0004] Coarse approximation actuators: These typically employ piezoelectric motors, inertial motors, or screw drives, which have large strokes and relatively low resolution. Their function is to rapidly and extensively move the entire assembly, equipped with a fine scanner and a probe tip, from its initial position to a location close to the sample surface (e.g., on the micrometer scale).

[0005] Fine scanning actuator: This typically employs a small-sized piezoelectric tube scanner or a piezoelectric stack. It is mounted on the coarse stage and its function is to scan the sample surface after the coarse approximation is completed.

[0006] However, in practical implementation, firstly, the aforementioned hierarchical structure inevitably increases the system's structural hierarchy and assembly complexity, leading to increased overall size and mass, and reduced mechanical stiffness. Secondly, coupling errors between each level of actuator are difficult to eliminate, making the system more sensitive to environmental vibrations, thus limiting its applicability in applications such as extremely low temperatures, strong magnetic fields, or space-constrained conditions. Finally, some coarse-approximation actuators are prone to transient overshoot during operation, making it difficult to achieve smooth and controllable quasi-static motion. This poses a risk of accidental tip impact with the sample surface, potentially damaging the probe or sample and affecting measurement safety and repeatability, thus requiring urgent solutions. Summary of the Invention

[0007] To avoid and overcome the technical problems existing in the prior art, the present invention provides an integrated probe stepping scanning component and stepping scanning method for a scanning probe microscope, which integrates the traditional coarse approximation and fine scanning functions onto a single piezoelectric element, thereby simplifying the system structure and improving performance.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] The scanning probe microscope's probe stepping scanning integrated assembly includes a frame and a piezoelectric tube fixed to the frame at its fixed end. The outer surface of the piezoelectric tube has at least three partition slits along its axial direction to divide the piezoelectric tube into at least three electrode partitions. At the partition slits of adjacent electrode partitions, decoupling slits penetrating the inside and outside of the piezoelectric tube are also provided. The starting point of the decoupling slits is located at the free end of the piezoelectric tube, and each decoupling slit is of equal length and shorter than the length of the partition slits. An elastic body is provided on the inner side of the piezoelectric tube, which elastically abuts against each electrode partition. The sliding friction between any electrode partition and the elastic body is less than the sum of the static friction between other electrode partitions and the elastic body. A probe assembly is installed on the elastic body near the fixed end of the piezoelectric tube.

[0010] As a further aspect of the present invention: the elastic body is a non-closed cylindrical structure with a C-shaped cross-section, and friction bodies are installed on the outer periphery of the elastic body near each electrode partition, forming a friction contact part that elastically abuts the electrode partition.

[0011] As a further aspect of the present invention: the friction body is a spherical structure that contacts the electrode partition point, and the friction bodies that elastically abut against each electrode partition are at least two that are spaced apart along the axial direction of the piezoelectric tube.

[0012] As a further embodiment of the present invention: the friction body is a strip-shaped structure that contacts the electrode partition line or an arc-shaped structure that contacts the surface.

[0013] As a further embodiment of the present invention: the friction body comprises an insulating substrate made of sapphire or zirconium oxide ceramic, and the outer surface of the insulating substrate is coated with a titanium nitride coating.

[0014] As a further embodiment of the present invention: the probe assembly includes a disc-shaped needle seat and a needle body coaxially fixed on the needle seat, the needle seat being coaxially arranged with the piezoelectric tube and fixed to the end of the piezoelectric tube adjacent to the elastomer.

[0015] As a further embodiment of the present invention: the outer edge of the fixed end of the piezoelectric tube is fixed to the frame by an insulating sleeve.

[0016] A step-scanning method, applied to the integrated probe step-scanning assembly of the scanning probe microscope, includes the following steps:

[0017] S1. Install the sample in the work area of ​​the frame;

[0018] S2. Apply a preset excitation voltage to one of the electrode sections to cause the electrode section to undergo axial tensile deformation pointing towards the free end, and keep the excitation voltage unchanged.

[0019] S3. Repeat step S2 until all electrode zones are subjected to the preset excitation voltage.

[0020] S4. Simultaneously cancel or synchronously adjust the excitation voltage of all electrode partitions so that all electrode partitions axially contract and deform towards the fixed end, thereby driving the inner elastic body and probe assembly to move along the piezoelectric tube axial direction toward the work station area.

[0021] S5. Repeat steps S2 to S4 until the probe assembly moves to the designated detection area;

[0022] S6. Apply a scanning drive voltage to the electrode sections of the piezoelectric tube to drive the probe assembly to scan and perform atomic-level scanning of the sample surface.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. This application introduces a decoupling slit that runs through the inside and outside of the piezoelectric tube at the partition seams separating the electrode sections. This partially decouples the mechanical coupling between adjacent electrode sections, allowing the deformation of one electrode section to occur more independently and reducing the influence on adjacent sections. In implementation, a preset excitation voltage is applied sequentially to each electrode section, causing each section to stretch axially independently. Since the sliding friction between the elastomer and the inner wall of any single electrode section must be less than the sum of the static friction between the elastomer and the inner walls of the remaining electrode sections, when the axial deformation of any electrode section causes relative sliding with the elastomer, the friction between the remaining stationary electrode sections and the elastomer keeps the elastomer stationary along with the other electrode sections. Therefore, after each electrode section is stretched sequentially, both the elastomer and the probe assembly remain stationary. When each electrode section is simultaneously retracted or adjusted, they simultaneously contract, causing the elastomer and probe assembly to move closer to the sample. This reciprocating operation allows the probe assembly to move stepwise to the designated detection area.

[0025] Since the length of the decoupling seam is less than the length of the partition seam, the piezoelectric tube at the fixed end remains a continuous whole. Applying a scanning driving voltage to the electrode partition of the piezoelectric tube can drive the probe assembly to scan and perform atomic-level scanning of the sample surface.

[0026] This application integrates coarse approximation driving and fine scanning functions into a single piezoelectric tube, achieving an integrated design for stepping drive and scanning execution. This avoids the increased size and multi-stage mechanical coupling errors caused by traditional hierarchical stacking structures, significantly reducing the system size and making it more suitable for space-constrained scanning probe microscopy applications. Furthermore, the integrated design of the piezoelectric tube and frame results in a short mechanical loop and high overall rigidity, which helps improve the system's natural frequency and scanning stability, thereby enhancing imaging accuracy. Simultaneously, the overall structure uses non-magnetic or low-magnetic materials, making it suitable for operation under extreme experimental conditions such as low temperatures and strong magnetic fields. Finally, the quasi-static driving method of step deformation accumulation avoids transient overshoot caused by inertial drive, effectively reducing the risk of probe tip impact with the sample during probe assembly insertion, thus protecting the probe assembly and sample, and facilitating high-stability spatial imaging measurements under low-temperature conditions.

[0027] 2. The main body of the elastomer adopts a C-shaped, non-closed cylindrical structure with relatively uniform radial elasticity, allowing it to expand outwards. The outer periphery of the elastomer elastically abuts against each electrode zone through friction elements, thus forming a friction contact portion that stably abuts against the inner wall of the corresponding electrode zone. This structural arrangement allows for the selection of materials with better compatibility with piezoelectric ceramics and a more stable coefficient of friction as friction elements. Furthermore, as wear-prone components, the friction elements can be replaced individually after wear, eliminating the need to replace the entire elastomer. On the other hand, by designing the shape and size of the friction elements, the pressure and state of the contact points can be precisely controlled.

[0028] 3. This application provides a rotatable friction body that can adopt a spherical structure for point contact with the electrode zones, a slender strip structure for line contact, or an arc-shaped structure for surface contact. Among these, the spherical point contact method has a small contact area and high pressure, which is beneficial for obtaining sufficient static friction force under a relatively small radial preload, while maintaining relatively stable frictional resistance during sliding. Line contact can provide a larger actual contact area, thereby obtaining a larger total static friction force under the same preload, suitable for scenarios requiring greater driving force. Surface contact can maximize the contact area, evenly distribute pressure, and reduce local wear and stress concentration on the contact surface, making it suitable for applications that pursue ultra-long life and smooth motion.

[0029] 4. The friction element uses sapphire or zirconium oxide ceramic as the insulating substrate. The insulating substrate has high hardness, excellent wear resistance, and is also an excellent insulator, avoiding the risk of frictional electrification or signal leakage.

[0030] 5. A titanium nitride coating is applied to the outer surface of the insulating substrate. The titanium nitride coating has a very stable coefficient of friction and combines high hardness with low wear rate, effectively improving the service durability of the friction body.

[0031] 6. The probe assembly includes a disc-shaped needle base coaxial with the piezoelectric tube and a needle body fixed coaxially. The disc-shaped needle base provides a large mounting base, is firmly connected to the elastomer, can effectively transmit driving force and suppress high-frequency vibration; in addition, it can keep the entire probe assembly coaxial with the piezoelectric tube, ensuring that the motion axis of the probe coincides with the mechanical axis of the piezoelectric tube, reducing nonlinear distortion and orthogonality error of the scanned image. Attached Figure Description

[0032] Figure 1 This is a three-dimensional cross-sectional structural diagram of the present invention.

[0033] Figure 2 This is a schematic diagram of the piezoelectric tube in this invention.

[0034] Figure 3 This is a schematic diagram of the structure of the elastomer and probe assembly in this invention.

[0035] Figure 4 This is a three-dimensional structural diagram of the present invention.

[0036] Figure 5 This is a timing voltage waveform diagram of each electrode zone during the step-moving phase of the probe assembly of the present invention.

[0037] In the figure: 10, frame; 20, probe assembly; 21, needle body; 22, needle seat; 30, elastomer; 31, friction body; 40, insulating sleeve; 50, piezoelectric tube; 51, partition seam; 52, decoupling seam; a, sample. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] For ease of understanding, the specific structure and operation of the present invention will be further described below with reference to the accompanying drawings:

[0040] The specific structure of this invention is as follows: Figure 1-5 As shown, its main structure includes a frame 10 as a supporting foundation. Preferably, the frame 10 is provided with a cavity for coaxially fixing an insulating sleeve 40, and a fixed end of a piezoelectric tube 50. Figure 1 The upper part shown, in actual implementation, is not limited to Figure 1The fixed end is shown facing upwards. Since the entire application is small enough, it allows for arbitrary orientation across the entire spatial angle, even in a narrow, confined space within a magnetic field. This is beneficial for measuring samples with anisotropic properties. a) The outer edge is rigidly fixed to the frame 10 via an insulating sleeve 40, suspended above the sample placement area of ​​the frame 10, achieving insulation between the piezoelectric tube 50 and the frame 10, while also facilitating the positioning and installation of the piezoelectric tube 50. At this time, the unfixed end of the piezoelectric tube 50 ( Figure 1 The lower end shown is the free end.

[0041] like Figure 2 As shown, the outer surface of the piezoelectric tube 50 has at least three partition slits 51 along its axial direction, thereby dividing the outer wall of the piezoelectric tube 50 into at least three independent electrode partitions, each of which can be individually voltage-applied. At each partition slit 51 between two adjacent electrode partitions, there is a decoupling slit 52 of equal length. The decoupling slit 52 starts from the free end of the piezoelectric tube 50 and extends towards the fixed end. The decoupling slit 52 is a through slit that penetrates both the inside and outside of the piezoelectric tube 50, and its length is approximately 3 / 5 to 1 / 2 of the length of the partition slit 51, which is significantly smaller than the length of the partition slit 51.

[0042] The decoupling slit 52 decouples the mechanical coupling between adjacent electrode sections, allowing the deformation (such as stretching) of one electrode section to occur more independently, reducing the impact on adjacent sections. This forms the basis for the subsequent movement of the probe assembly 20 along the axial direction of the piezoelectric tube 50. Simultaneously, because the length of the decoupling slit 52 is less than the length of the partition slit 51, the piezoelectric tube 50 remains a continuous whole at its fixed end. This ensures that when a scanning drive voltage is applied to the electrode sections of the piezoelectric tube 50, the probe assembly 20 can be driven to perform a scanning action.

[0043] Specifically, such as Figure 1 and Figure 3 As shown, an elastic body 30 made of elastic material is provided in the inner cavity of the piezoelectric tube 50. The probe assembly 20 for scanning is fixed to the elastic body 30 near the fixed end of the piezoelectric tube 50 by threads or adhesive. In addition, the elastic body 30 is elastically abutted against each electrode section on the inner side of the piezoelectric tube 50.

[0044] It is worth noting that the sliding friction between the elastomer 30 and the inner wall of any single electrode partition must be less than the sum of the static friction between it and the inner walls of the remaining electrode partitions. That is, when the axial deformation of any electrode partition causes relative sliding with the elastomer 30, the friction between the other stationary electrode partitions and the elastomer 30 keeps the elastomer 30 stationary along with the other electrode partitions. This is one of the core conditions for achieving the axial movement of the probe assembly 20 along the piezoelectric tube 50 in this application. In actual implementation, since the number of electrode partitions with static friction to the elastomer 30 is greater than the number of electrode partitions with sliding friction to the elastomer 30, it is only necessary to maintain the relatively uniform elastic force between the elastomer 30 and each electrode partition, and supplement this with the selection of the contact surface material and the configuration of the radial pressure of the elastomer 30, to achieve the above requirements.

[0045] The working principle of the above structure is explained below with reference to a specific step-scan method:

[0046] In this embodiment, four partition slits 51 are provided, thus dividing the piezoelectric tube 50 into four electrode partitions, which are sequentially named as electrode partition A, electrode partition B, electrode partition C, and electrode partition D around the circumference of the piezoelectric tube 50. When applied to scanning probe microscope operations, adjacent electrode partitions are electrically insulated, and the inner wall of the piezoelectric tube 50 is provided with a common inner electrode and grounded.

[0047] S1. Install sample a in the work station area of ​​frame 10, such as Figure 1 The position is directly above the probe assembly 20 shown; after this, the stepping motion phase of the probe assembly 20 toward sample a can begin.

[0048] S2. A preset excitation voltage is applied to one of the electrode sections (i.e., electrode section A), causing the electrode section to undergo axial tensile deformation towards its free end due to the inverse piezoelectric effect. Then, its inner wall slides downwards relative to the elastic body 30 in contact with it to a predetermined length under the preset excitation voltage (the descriptions of upwards and downwards here and below refer to...). Figure 1 (Perspective description). Since there is no voltage change in electrode sections B, C, and D, they will not undergo stretching deformation at this time; that is, there is static friction between them and the elastic body 30. Because the sum of the static friction forces at the corresponding elastic contact points between them and the elastic body 30 is much greater than the sliding friction force between electrode section A and the elastic body 30, the elastic body 30 and the probe assembly 20 remain stationary. Thereafter, the excitation voltage remains constant. The waveform diagram of the excitation voltage versus time for electrode section A is shown below. Figure 5 The waveform is shown in (A).

[0049] S3. Repeat step S2: If the second electrode section to be applied with the preset excitation voltage is B, then electrode section B will also undergo axial tensile deformation pointing towards the free end due to the inverse piezoelectric effect. That is, its inner wall will slide downward relative to the elastic body 30 it contacts to the predetermined length under the preset excitation voltage. Similarly, since electrode sections A, C and D have not undergone voltage changes at this time, they will not undergo tensile deformation. That is, there is static friction between them and the elastic body 30. Since the sum of the static friction forces at the corresponding elastic contact points between them and the elastic body 30 is much greater than the sliding friction force between electrode section B and the elastic body 30, the elastic body 30 and the probe assembly 20 remain stationary. After this, the excitation voltage is kept constant.

[0050] Similarly, a preset excitation voltage is applied sequentially to electrode partitions C and D, causing the elastomer 30 and probe assembly 20 to remain stationary while electrode partitions C and D undergo axial stretching deformation towards their free ends to a predetermined length under the preset excitation voltage. At this point, the preset excitation voltage has been applied to all electrode partitions, and the axial stretching of all electrode partitions is complete. The waveforms of the excitation voltage versus time for electrode partitions B, C, and D are shown below. Figure 5 The waveforms in (B), (C), and (D) are shown in the diagram.

[0051] S4. Simultaneously cancel or synchronously adjust the excitation voltage of all electrode sections to a smaller voltage value. At this time, the four previously stretched electrode sections synchronously contract upwards and restore their original length. During the contraction process, all electrode sections are in a static friction connection with the friction body 31. Therefore, the contracted electrode sections of the piezoelectric tube 50 will pull the elastic body 30 and the probe assembly 20 upwards by one step, that is, the probe assembly 20 moves one step closer to the work station area where sample a is located.

[0052] S5. Repeat steps S2 to S4 above, and the probe assembly 20 will move upward (towards sample a) step by step to achieve coarse approximation until the probe assembly 20 moves to the designated detection area; thereafter, the subsequent probe scanning stage can begin.

[0053] S6. Apply a scanning drive voltage to the electrode partition of the piezoelectric tube 50. At this time, the piezoelectric tube 50 will produce precise bending and stretching deformation, driving the probe assembly 20 located at its end to perform nanoscale scanning motion, completing the atomic-level scanning of the surface of sample a, thereby obtaining a high-resolution morphological image of the surface of sample a.

[0054] The scanning procedure for this piezoelectric tube 50 can be performed using conventional scanning methods found in existing technologies. For ease of understanding, the scanning procedure is briefly described below:

[0055] Assume electrode partitions A and C are positioned opposite each other along a first direction to generate bending displacement along that first direction; electrode partitions B and D are positioned opposite each other along a second direction orthogonal to the first direction to generate bending displacement along that second direction. The first direction is defined as the fast scan axis (X-axis), and the second direction is defined as the slow scan axis (Y-axis).

[0056] During the scanning process, the driving voltage for each electrode zone is applied as follows:

[0057] Electrode partitions A and C are loaded with fast-axis sawtooth wave voltages +V(t) and -V(t) of equal amplitude but opposite polarity to produce periodic bending deformation along the fast scanning axis.

[0058] Electrode partitions B and D are loaded with slow-axis sawtooth wave voltages +V(t) and -V(t) of equal amplitude but opposite polarity to produce a stepped or quasi-linear displacement along the slow scanning axis.

[0059] The internal electrode remains grounded to provide a stable reference potential.

[0060] By coordinating the control of the voltage amplitude, polarity, and timing of the four external electrode regions, a two-dimensional square scanning trajectory of the scanning probe on the sample surface is achieved.

[0061] To achieve a regular two-dimensional square scanning area, both the fast and slow scanning axes use sawtooth wave drive signals, and their periods satisfy a strict integer multiple relationship.

[0062] Within a complete two-dimensional scanning cycle:

[0063] The period of the fast scan axis sawtooth wave is denoted as It is used to complete a linear displacement from the start to the end of the scan within a single scan line; the period of the slow scan axis sawtooth wave is denoted as... This is used to perform line-by-line displacement throughout the entire scanning process;

[0064] The two satisfy the following relationship:

[0065] ;

[0066] Where N is the number of scan lines, corresponding to the number of pixels in the slow scan direction of the image.

[0067] This period multiple relationship ensures that the fast scan axis can complete one full scan line within one cycle when the slow scan axis voltage remains constant; and after each step transition of the slow scan axis, the fast scan axis starts scanning the next line again, thus forming a regular two-dimensional scan array.

[0068] After the scan is completed, in steps S1 to S5 above, the applied excitation voltage is set to be opposite to the previously preset excitation voltage for the electrodes, which drives the probe assembly 20 away from the sample a to achieve reset. That is, each electrode section contracts at the excitation voltage, and stretches and resets after the excitation voltage is removed, causing the probe assembly 20 to move downward away from the sample a. By repeating this operation, the probe assembly 20 can be moved away from the sample a in a step-by-step manner.

[0069] Alternatively, a preset excitation voltage can be applied to all electrode sections to simultaneously stretch them axially downwards, moving the probe assembly 20 away from the sample a. Then, the preset excitation voltages for each electrode section can be removed sequentially, keeping the probe assembly 20 stationary. Repeating this operation allows the probe assembly 20 to be moved away from the sample a in a step-by-step manner.

[0070] This application integrates coarse approximation drive and fine scanning functions into a single piezoelectric tube 50, achieving an integrated design of stepping drive and scanning execution. This avoids the increased volume and multi-level mechanical coupling errors caused by traditional hierarchical stacking structures, thus significantly reducing the system size and making it more suitable for space-constrained scanning probe microscopy applications. Furthermore, the integrated design of the piezoelectric tube 50 and frame 10 results in a short mechanical loop and high overall rigidity, which helps improve the system's natural frequency and scanning stability, thereby enhancing imaging accuracy. Simultaneously, the overall structure uses non-magnetic or low-magnetic materials, making it suitable for operation under extreme experimental conditions such as low temperatures and strong magnetic fields. Finally, the quasi-static drive method of step deformation accumulation avoids transient overshoot caused by inertial drive, effectively reducing the risk of the probe tip colliding with the sample during probe assembly 20 insertion, thus protecting the probe assembly 20 and sample a, and facilitating high-stability real-space imaging measurements under low-temperature conditions.

[0071] Based on the above, such as Figure 3 As shown, the main body of the elastomer 30 is configured as a non-closed cylindrical structure with a C-shaped cross-section, possessing relatively uniform radial elasticity and capable of opening outwards. For example... Figure 2 As shown, in its natural state, the outer diameter of the elastomer 30 is slightly smaller than the inner diameter of the piezoelectric tube 50. When it is placed inside the piezoelectric tube 50, it expands due to its own elasticity and maintains tight contact with the inner walls of each electrode zone, forming an elastic abutment. To further optimize friction performance and reliability, such as... Figure 2 and Figure 3 As shown, mounting holes are machined on the outer peripheral wall of the elastomer 30 at the positions corresponding to the four electrode zones, and an independent friction body 31 is embedded in each hole (or directly fixed to the outer surface of the elastomer 30). These friction bodies 31 are preferably small spheres made of high-hardness, wear-resistant alumina ceramic. They are pushed outward by the elastic pre-pressure of the C-shaped opening of the elastomer 30 itself, thereby forming a friction contact part that stably abuts against the inner wall of the corresponding electrode zone.

[0072] The advantage of using an independent friction element 31 instead of direct contact with the elastic body 30 is that:

[0073] On the one hand, materials that are better matched with piezoelectric ceramics and have a more stable coefficient of friction can be selected as friction body 31. On the other hand, as a wear part, friction body 31 can be replaced separately after wear, without having to replace the entire elastomer 30.

[0074] On the other hand, by designing the shape and size of the friction body 31, the pressure and state of the contact point can be precisely controlled.

[0075] In practical implementation, the elastomer 30 can also be implemented in other ways, as long as the elastic force between it and each electrode zone is relatively uniform. For example, the elastomer 30 can be composed of multiple independent elastic beams, which are evenly distributed circumferentially and connected as a whole by an upper connecting ring and a lower base ring. The connecting ring is used to fix the needle seat 22 of the probe assembly 20, while the base ring serves to position the bottom and increase the overall rigidity. Each elastic beam corresponds to one electrode zone, and a friction body 31 is installed on the outer side of its free middle section or directly elastically abuts against the electrode zone.

[0076] Alternatively, the elastomer 30 is formed by diffusion welding or precision bonding of three layers of materials. The inner layer is a support ring that provides the main support; the middle layer is a highly elastic damping material, such as elastic rubber, which provides elasticity and absorbs and suppresses high-frequency micro-vibrations generated during stepping and scanning; the outer layer is a high-hardness, low-friction coefficient protrusion or strip that can be directly used as a friction contact surface to achieve the above effects.

[0077] Furthermore, based on the above, such as Figure 3 As shown, the shape and arrangement of the friction body 31 are further defined. Specifically, the friction body 31 has a spherical structure, preferably made of sapphire spheres. For each electrode zone, at least two such spherical friction bodies 31 are arranged at intervals along the axial direction of the piezoelectric tube 50. This spherical point contact method has a small contact area and high pressure, which is beneficial for obtaining sufficient static friction force under a small radial preload, while the frictional resistance is relatively stable during sliding. In addition, the arrangement of at least two friction bodies 31 provides at least two defined contact points for each electrode zone, which can effectively prevent the elastomer 30 from tilting or deflecting relative to the zone, ensuring the linearity and stability of the movement during stepping and scanning.

[0078] Of course, in actual implementation, the friction body 31 can also adopt the following specific structural layout:

[0079] The friction element 31 can be a slender strip structure that makes line contact with the inner wall of the electrode partition. For example, a slender sapphire rod or silicon nitride ceramic rod can be attached axially along the piezoelectric tube 50 to a corresponding groove on the outer wall of the elastomer 30. This line contact can provide a larger actual contact area, thereby obtaining a larger total static friction force under the same preload, which is suitable for scenarios requiring greater driving force.

[0080] Alternatively, the friction body 31 can also be a surface-contact arc-shaped structure. That is, a sapphire or silicon nitride ceramic sheet with an inner arc surface matching the curvature of the inner wall of the piezoelectric tube 50 and an outer plane fixed to the elastomer 30 is machined. Surface contact can maximize the contact area, distribute pressure evenly, reduce local wear and stress concentration on the contact surface, and is suitable for applications that require ultra-long life and smooth motion.

[0081] In addition to using sapphire or zirconium oxide ceramic as the insulating substrate, the friction body 31 is further coated with a titanium nitride layer on its outer surface. The insulating substrate has high hardness, excellent wear resistance, and is a superior insulator, completely avoiding the risk of frictional electrification or signal leakage. The titanium nitride coating has a very stable coefficient of friction and combines high hardness with a low wear rate.

[0082] In addition, such as Figure 3 As shown, the probe assembly 20 includes a disc-shaped needle holder 22 with a diameter slightly smaller than the inner diameter of the piezoelectric tube 50. The needle holder 22 is preferably made of titanium alloy or stainless steel, and a needle body 21, made of a single or composite material such as tungsten, platinum-iridium alloy, silver, or gold, is coaxially bonded to it through its central through-hole using conductive adhesive. The needle holder 22 is securely mounted on the lower end face of the elastomer 30 near the fixed end of the piezoelectric tube 50 via threaded holes on its edge or by adhesive. The disc-shaped needle holder 22 provides a large mounting base, ensuring a firm connection with the elastomer 30, effectively transmitting driving force and suppressing high-frequency vibrations. Furthermore, it keeps the entire probe assembly 20 coaxial with the piezoelectric tube 50, ensuring that the probe's axis of motion coincides with the mechanical axis of the piezoelectric tube 50, reducing nonlinear distortion and orthogonality errors in the scanned image.

[0083] Of course, those skilled in the art will recognize that the present invention is not limited to the details of the exemplary embodiments described above, but also includes the same or similar structures that can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0084] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0085] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

Claims

1. A probe stepping and scanning integrated assembly for a scanning probe microscope, characterized in that, The device includes a frame (10) and a piezoelectric tube (50) with its fixed end fixed on the frame (10). The outer surface of the piezoelectric tube (50) is provided with at least three partition seams (51) along its axial direction to divide the piezoelectric tube (50) into at least three electrode partitions. At the partition seams (51) of adjacent electrode partitions, there are also corresponding decoupling seams (52) that penetrate the inside and outside of the piezoelectric tube (50). The starting point of the decoupling seam (52) is located at the free end of the piezoelectric tube (50), and each decoupling seam (52) is of equal length and is shorter than the length of the partition seam (51). An elastic body (30) is provided on the inner side of the piezoelectric tube (50) and it elastically abuts against each electrode partition. The sliding friction between any electrode partition and the elastic body (30) is less than the sum of the static friction between other electrode partitions and the elastic body (30). A probe assembly (20) is installed on the elastic body (30) at the adjacent fixed end of the piezoelectric tube (50).

2. The integrated probe stepping and scanning assembly of the scanning probe microscope according to claim 1, characterized in that, The elastic body (30) is a non-closed cylindrical structure with a C-shaped cross-section. Friction bodies (31) are installed on the outer periphery of the elastic body (30) near each electrode partition, and the friction bodies (31) form the friction contact part of the elastic abutting electrode partition.

3. The integrated probe stepping and scanning assembly of the scanning probe microscope according to claim 2, characterized in that, The friction body (31) is a spherical structure that contacts the electrode partition point, and the friction bodies (31) that elastically abut against each electrode partition are at least two of them spaced apart along the axial direction of the piezoelectric tube (50).

4. The integrated probe stepping and scanning assembly of the scanning probe microscope according to claim 2, characterized in that, The friction body (31) is a strip-shaped structure that contacts the electrode partition line or an arc-shaped structure that contacts the surface.

5. The integrated probe stepping and scanning assembly of a scanning probe microscope according to any one of claims 2-4, characterized in that, The friction body (31) comprises an insulating substrate made of sapphire or zirconium oxide ceramic.

6. The integrated probe stepping and scanning assembly of the scanning probe microscope according to claim 5, characterized in that, The outer surface of the insulating substrate is coated with a titanium nitride layer.

7. The integrated probe stepping and scanning assembly of a scanning probe microscope according to any one of claims 1-4, characterized in that, The probe assembly (20) includes a disc-shaped needle seat (22) and a needle body (21) coaxially fixed on the needle seat (22). The needle seat (22) is coaxially arranged with the piezoelectric tube (50) and fixed on the end of the adjacent piezoelectric tube (50) on the elastomer (30).

8. The integrated probe stepping and scanning assembly of a scanning probe microscope according to any one of claims 1-4, characterized in that, The outer edge of the fixed end of the piezoelectric tube (50) is fixed to the frame (10) by an insulating sleeve (40).

9. A step-scanning method, wherein the step-scanning method is applied to the probe step-scanning integrated assembly of the scanning probe microscope according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Install the sample (a) in the work area of ​​the frame (10); S2. Apply a preset excitation voltage to one of the electrode sections to cause the electrode section to undergo axial tensile deformation pointing towards the free end, and keep the excitation voltage unchanged. S3. Repeat step S2 until all electrode zones are subjected to the preset excitation voltage. S4. Simultaneously cancel or synchronously adjust the excitation voltage of all electrode partitions so that all electrode partitions axially contract and deform towards the fixed end, thereby driving the inner elastic body (30) and probe assembly (20) to move along the piezoelectric tube (50) axially toward the work station area. S5. Repeat steps S2 to S4 until the probe assembly (20) moves to the designated detection area; S6. Apply a scanning drive voltage to the electrode partition of the piezoelectric tube (50) to drive the probe assembly (20) to scan and perform an atomic-level scan of the surface of the sample (a).

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