Nano-pan-tilt head with high static and low dynamic stiffness

Abstract

The present invention discloses a nano-pan-tilt platform with high static and low dynamic stiffness characteristics. The nano-pan-tilt platform includes a base frame, an output platform, an atomic force microscope probe, and a quasi-zero stiffness mechanism. The output platform is movably mounted on the base frame in the vertical direction. The atomic force microscope probe is mounted on the output platform. The quasi-zero stiffness mechanism includes a first mounting block, a second mounting block, and a quasi-zero stiffness unit. The quasi-zero stiffness unit is mounted between the first mounting block and the second mounting block. The first mounting block is used to connect to the base frame, and the second mounting block is used to connect to the output platform. The quasi-zero stiffness unit includes a positive stiffness mechanism and a negative stiffness mechanism. The positive stiffness mechanism is used to apply a supporting force to the output platform. The negative stiffness mechanism is arranged in the horizontal direction and is configured to offset the vertical stiffness of the positive stiffness mechanism when the positive stiffness mechanism applies a supporting force to the output platform. By introducing the quasi-zero stiffness structure into the nano-pan-tilt platform, the nano-pan-tilt platform achieves a lower system natural frequency.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration reduction of precision instruments, and in particular to a nanometer platform with high static and low dynamic stiffness characteristics. Background Art

[0002] The nano-PTZ with active / passive vibration suppression is a comprehensive vibration isolation platform that combines active and passive vibration isolation technologies. It is designed to provide more efficient and comprehensive vibration control to meet the stringent requirements of vibration-sensitive equipment or systems.

[0003] In order to improve the vibration reduction capability of the traditional active / passive suppression fusion nano-pan-tilt platform in the resonance area, the method of increasing damping in the passive vibration isolation system is usually adopted to suppress the resonance frequency and increase the bandwidth.

[0004] However, the vibration reduction method of increasing damping weakens the characteristic of the passive vibration isolation device in suppressing vibration in the high frequency band. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one objective of the present invention is to provide a nano-pan-tilt platform with high static and low dynamic stiffness. By introducing a quasi-zero stiffness structure, the nano-pan-tilt platform achieves high static and low dynamic stiffness. This high static and low dynamic stiffness characteristic achieves a lower system natural frequency without sacrificing load-bearing capacity and stability, thereby achieving vibration suppression in the resonant and high-frequency regions.

[0006] The present invention proposes a nano-pan-tilt platform with high static and low dynamic stiffness characteristics. The nano-pan-tilt platform includes a base frame, an output platform, an atomic force microscope probe and a quasi-zero stiffness mechanism; the output platform is movably mounted on the base frame along the vertical direction; the atomic force microscope probe is mounted on the output platform; the quasi-zero stiffness mechanism includes a first mounting block, a second mounting block and a quasi-zero stiffness unit, the quasi-zero stiffness unit is mounted between the first mounting block and the second mounting block, the first mounting block is used to connect the base frame, and the second mounting block is used to connect the output platform; the quasi-zero stiffness unit includes a positive stiffness mechanism and a negative stiffness mechanism, the positive stiffness mechanism is used to apply a supporting force to the output platform, and the negative stiffness mechanism is arranged along the horizontal direction and is configured to offset the stiffness of the positive stiffness mechanism in the vertical direction when the positive stiffness mechanism applies a supporting force to the output platform.

[0007] In some embodiments, the first mounting block and the second mounting block are arranged along the vertical direction; the positive stiffness mechanism includes four positive stiffness elastic members connected end to end, the positive stiffness elastic members are connected and sequentially form a first intersection, a second intersection, a third intersection and a fourth intersection, and each of the positive stiffness elastic members is configured to rotate relative to the intersection; the negative stiffness mechanism includes a negative stiffness elastic member, one end of the negative stiffness elastic member is connected to the first intersection, and the other end of the negative stiffness elastic member is connected to the third intersection, and the line between the first intersection and the third intersection is parallel to the horizontal direction; the second intersection is fixed to the first mounting block, and the fourth intersection is fixed to the second mounting block.

[0008] In some embodiments, a line connecting the second intersection point and the fourth intersection point is parallel to the vertical direction.

[0009] In some embodiments, the quasi-zero stiffness unit is a one-piece piece.

[0010] In some embodiments, the first mounting block and the second mounting block are arranged along the vertical direction; the quasi-zero stiffness unit includes a frame, the frame includes four trusses connected end to end, and two adjacent trusses are rotatable; the positive stiffness mechanism includes a positive stiffness elastic member, the positive stiffness elastic member is provided at a diagonal of the frame, one end of the positive stiffness elastic member is hinged to the first frame intersection of the frame, and the other end of the positive stiffness elastic member is hinged to the third frame intersection of the frame, the first frame intersection is connected to the first mounting block, and the third frame intersection is connected to the second mounting block; the negative stiffness mechanism includes a negative stiffness elastic member, the negative stiffness elastic member is provided at another diagonal of the frame, one end of the negative stiffness elastic member is hinged to the second frame intersection of the frame, and the other end of the negative stiffness elastic member is hinged to the fourth frame intersection of the frame; the positive stiffness elastic member is arranged parallel to the vertical direction, and the negative stiffness elastic member is arranged parallel to the horizontal direction.

[0011] In some embodiments, different diagonals of the frame intersect to form a fifth frame intersection; there are two positive stiffness elastic members, one is located between the first frame intersection and the fifth frame intersection, and the other is located between the third frame intersection and the fifth frame intersection; there are two negative stiffness elastic members, one is located between the second frame intersection and the fifth frame intersection, and the other is located between the fourth frame intersection and the fifth frame intersection.

[0012] In some embodiments, the nano-pan head further includes a flexible leaf spring, one end of which is connected to the base frame, and the other end of which is connected to the output platform, and the flexible leaf spring is used to apply elastic force in the vertical direction to the output platform.

[0013] In some embodiments, the first mounting block and the second mounting block are arranged along the horizontal direction; the positive stiffness mechanism includes a flexible leaf spring member, one end of the flexible leaf spring member is connected to the first mounting block, and the other end of the flexible leaf spring member is connected to the second mounting block, and the flexible leaf spring member deflects and deforms to apply an elastic force in the vertical direction; the negative stiffness mechanism includes a negative stiffness elastic member, one end of which is connected to the first mounting block, and the other end of which is connected to the second mounting block.

[0014] In some embodiments, the first mounting block and the second mounting block are arranged along the vertical direction; the first mounting block has a mounting groove, and the second mounting block is movably arranged in the mounting groove along the vertical direction; the positive stiffness mechanism includes a positive stiffness elastic member, one end of the positive stiffness elastic member is connected to the bottom wall of the mounting groove, and the other end of the positive stiffness elastic member is connected to the top wall of the second mounting block; the negative stiffness mechanism includes a negative stiffness elastic member, and the negative stiffness elastic member is a plurality of negative stiffness elastic members arranged at intervals around the first mounting block, one end of each of the negative stiffness elastic members is connected to the groove peripheral wall of the mounting groove, and the other end of each of the negative stiffness elastic members is on the side peripheral wall of the second mounting block; the extension lines of the negative stiffness elastic members intersect on the straight line where the positive stiffness elastic member is located.

[0015] In some embodiments, the nano-pan-tilt platform further includes a hard spring component, one end of which is connected to the base frame, and the other end of which is connected to the output platform, and the hard spring component is used to apply elastic force in the vertical direction to the output platform.

[0016] In combination with the technical solution, it can be seen that the embodiment provided by the present invention has the following advantages: the first mounting block is fixedly connected to the base frame, the second mounting block is fixedly connected to the output platform, the quasi-zero stiffness unit includes a positive stiffness mechanism and a negative stiffness mechanism, the positive stiffness mechanism can apply a supporting force to the output platform, that is, the direction of the supporting force generated by the positive stiffness mechanism is parallel to the vertical direction and opposite to the direction of the gravity exerted on the output platform, so the positive stiffness mechanism increases the bearing capacity and the static stiffness is maintained at a high level; the negative stiffness mechanism is arranged in the horizontal direction, and when the positive stiffness mechanism applies a supporting force to the output platform, the negative stiffness mechanism offsets the stiffness of the positive stiffness mechanism in the vertical direction, that is, the positive stiffness mechanism and the negative stiffness mechanism are connected in parallel, and its dynamic stiffness is close to zero. This means that the quasi-zero stiffness unit exhibits a strong bearing capacity when subjected to static loads, and exhibits a lower stiffness when facing dynamic loads, which is conducive to achieving vibration isolation and vibration reduction effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 Schematic diagram of the overall structure of the nano pan-tilt platform in the first embodiment;

[0019] Figure 2 This is a comparison chart of the vibration suppression effects of nano-pan-tilt platforms. The three different lines in the figure represent the vibration suppression effect of a traditional nano-pan-tilt platform with active / passive vibration suppression, the vibration suppression effect after adding damping to the traditional nano-pan-tilt platform with active / passive vibration suppression, and the vibration suppression effect after adding a quasi-zero stiffness mechanism to the traditional nano-pan-tilt platform with active / passive vibration suppression.

[0020] Figure 3 Schematic diagram of the overall structure of the nano pan-tilt platform according to the second embodiment;

[0021] Figure 4 is a schematic diagram of a quasi-zero stiffness mechanism of a second embodiment;

[0022] Figure 5 1 is a schematic diagram of the overall structure of the nano pan-tilt platform according to the third embodiment;

[0023] Figure 6 is a schematic diagram of a quasi-zero stiffness mechanism of a third embodiment;

[0024] Figure 7 1 is a schematic diagram of the overall structure of the nano pan-tilt platform according to the fourth embodiment;

[0025] Figure 8 is a schematic diagram of a quasi-zero stiffness mechanism of a fourth embodiment;

[0026] Figure 9 1 is a schematic diagram of the overall structure of the nano pan-tilt platform according to the fifth embodiment;

[0027] Figure 10 It is a schematic diagram of the quasi-zero stiffness mechanism of the fifth embodiment.

[0028] Reference numerals:

[0029] First embodiment:

[0030] Nano-pan-tilt platform 101 with high static and low dynamic stiffness, base frame 102, output platform 103, atomic force microscope probe 104, quasi-zero stiffness mechanism 105;

[0031] Second embodiment:

[0032] Nano-stage 201 with high static and low dynamic stiffness characteristics, base frame 202, output platform 203, atomic force microscope probe 204, quasi-zero stiffness mechanism 205, first mounting block 215, second mounting block 225, quasi-zero stiffness unit 235, positive stiffness mechanism 2135, negative stiffness mechanism 2235, first intersection a2, second intersection b2, third intersection c2, fourth intersection d2, flexible leaf spring 206, hard spring 207, drive assembly 208;

[0033] Third embodiment:

[0034] Nano-stage 301 with high static and low dynamic stiffness characteristics, base frame 302, output platform 303, atomic force microscope probe 304, quasi-zero stiffness mechanism 305, first mounting block 315, second mounting block 325, quasi-zero stiffness unit 335, positive stiffness mechanism 3135, negative stiffness mechanism 3235, frame 32135, first frame intersection a3, second frame intersection b3, third frame intersection c3, fourth frame intersection d3, fifth frame intersection e3, flexible leaf spring 306, hard spring 307, drive assembly 308;

[0035] Fourth embodiment:

[0036] Nano-stage 401 with high static and low dynamic stiffness characteristics, base frame 402, output platform 403, atomic force microscope probe 404, quasi-zero stiffness mechanism 405, first mounting block 415, second mounting block 425, quasi-zero stiffness unit 435, positive stiffness mechanism 4135, negative stiffness mechanism 4235, flexible leaf spring 406, hard spring 407, and drive assembly 408;

[0037] Fifth embodiment:

[0038] Nano-pan-tilt head 501 with high static and low dynamic stiffness characteristics, base frame 502, output platform 503, atomic force microscope probe 504, quasi-zero stiffness mechanism 505, first mounting block 515, mounting groove 5515, second mounting block 525, quasi-zero stiffness unit 535, positive stiffness mechanism 5135, negative stiffness mechanism 5235, flexible leaf spring component 506, hard spring component 507, and drive assembly 508. DETAILED DESCRIPTION

[0039] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0040] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0041] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0042] The Nano PTZ is a comprehensive vibration isolation platform that combines active and passive vibration isolation technologies. It is designed to provide more efficient and comprehensive vibration control to meet the stringent requirements of vibration-sensitive equipment or systems.

[0043] Specifically, active vibration isolation technology applies a certain control strategy to drive the actuator according to the detected vibration signal, thereby achieving the purpose of suppressing or eliminating vibration. Passive vibration isolation technology mainly utilizes material properties, such as using coil springs, vibration isolation rubber pads, air springs, etc. to isolate foundation vibration or isolate the vibration source so that its vibration is not transmitted to the equipment or system. Although the structure used in passive vibration isolation technology is simpler, passive vibration isolation technology performs poorly in low-frequency resonance, has low vibration isolation performance, and requires a long stabilization time. The applicant proposes an active / passive vibration suppression fusion nano-pan-tilt platform that can combine the advantages of active vibration isolation technology and passive vibration isolation technology. Through the coordinated work of active vibration isolation technology and passive vibration isolation technology, it not only improves the vibration isolation efficiency, but also broadens the vibration isolation frequency range. This comprehensive platform can more effectively reduce the impact of vibration on equipment or systems, thereby improving working stability and overall performance. Specifically, the vibration isolation platform is an active-passive hybrid vibration isolation strategy improved by flexible nano-positioning technology. The system combines the high resolution, high force and frictionless characteristics of a piezoelectric actuator (PZT) with the high power and high speed characteristics of a voice coil motor (VCM) to improve vibration isolation performance.

[0044] However, the applicant also found that the inherent damping level of the system makes the vibration reduction effect in the resonance area poor. The traditional active / passive vibration suppression fusion nano-panel still focuses on suppressing resonance by changing the damping of the system. Increasing the damping weakens the passive vibration isolation device's ability to suppress vibration in the high-frequency band. The main function of increasing the damping is to reduce vibration by consuming energy. This energy loss also means an increase in the effective mass of the system, which may lead to problems such as reduced system efficiency. These methods only focus on vibration suppression in the resonance area of ​​the system, and their high-frequency vibration suppression effects are subject to certain limitations. At the same time, although the design of the low-rigidity structure can reduce the natural frequency, it also makes it difficult to effectively suppress resonance. Faced with this challenge, how to improve the vibration isolation performance of the active / passive vibration suppression fusion nano-panel in the resonance area to optimize the overall vibration isolation effect has become the key to achieving higher precision for the nano-panel.

[0045] First embodiment

[0046] Figure 1 FIG. 1 shows a nano-pan-tilt platform 101 with high static and low dynamic stiffness characteristics according to the first embodiment of the present invention. Figure 1 As can be seen, the nano-stage 101 includes a base frame 102, an output platform 103, an atomic force microscope probe 104, and a quasi-zero stiffness mechanism 105. The output platform 103 is vertically mounted on the base frame 102, and the atomic force microscope probe 104 is mounted on the output platform 103. The quasi-zero stiffness mechanism 105 includes a first mounting block, a second mounting block, and a quasi-zero stiffness unit. The quasi-zero stiffness unit is mounted between the first mounting block and the second mounting block. The first mounting block is connected to the base frame 102, and the second mounting block is connected to the output platform 103.

[0047] A drive assembly is mounted on the base frame 102. The output end of the drive assembly is connected to the output platform 103, driving the output platform 103 to move vertically relative to the base frame 102. A staff member controls the movement of the drive assembly, which in turn drives the output platform 103, which in turn drives the AFM probe 104, thereby adjusting the distance between the AFM probe 104 and the object being observed.

[0048] As the output platform 103 moves relative to the base, it vibrates, which is transmitted to the atomic force microscope probe 104. The quasi-zero stiffness mechanism 105, positioned between the output platform 103 and the base, gives the nano-pan-tilt platform 101 high static stiffness and low dynamic stiffness, enhancing the vibration isolation and load-bearing capacity of the output platform 103.

[0049] The quasi-zero stiffness mechanism 105 may include one or more quasi-zero stiffness units. The number of quasi-zero stiffness units is not limited here.

[0050] The specific working principle of the quasi-zero stiffness mechanism 105 is as follows: the first mounting block is fixedly connected to the base frame, and the second mounting block is fixedly connected to the output platform 103. The quasi-zero stiffness unit includes a positive stiffness mechanism and a negative stiffness mechanism. The positive stiffness mechanism can apply a supporting force to the output platform 103, that is, the direction of the supporting force generated by the positive stiffness mechanism is parallel to the vertical direction and opposite to the direction of the gravity acting on the output platform 103. Therefore, the positive stiffness mechanism increases the load-bearing capacity and maintains the static stiffness at a high level; the negative stiffness mechanism is arranged in the horizontal direction, and when the positive stiffness mechanism applies a supporting force to the output platform 103, the negative stiffness mechanism offsets the stiffness of the positive stiffness mechanism in the vertical direction. That is, the positive stiffness mechanism and the negative stiffness mechanism are connected in parallel, and their dynamic stiffness is close to zero. This means that the quasi-zero stiffness unit exhibits a strong load-bearing capacity when subjected to static loads, and exhibits a lower stiffness when facing dynamic loads, which is conducive to achieving vibration isolation and vibration reduction effects.

[0051] In the prior art, although there are studies and applications on the vibration reduction system of the negative stiffness mechanism, there is currently no solution to improve the performance of the active / passive vibration suppression fusion nano pan-tilt platform through the high static and low dynamic characteristics of the quasi-zero stiffness structure. The current active / passive vibration suppression fusion nano pan-tilt platform system has an inherent damping level, which makes the vibration reduction effect in the resonance area relatively low. The active / passive vibration suppression fusion nano pan-tilt platform experiences a sharp amplification of vibration energy in the resonance area. Passive vibration isolation structures usually have fixed resonance frequencies and damping characteristics. The performance of these structures in the resonance area will also be affected, thereby reducing their vibration isolation effect. In order to improve this problem, the present invention adds a quasi-zero stiffness mechanism 105 to the nano pan-tilt platform 101, and uses the quasi-zero stiffness mechanism 105 to significantly reduce the natural frequency of the nano pan-tilt platform 101, thereby achieving effective isolation of low-frequency vibrations.

[0052] See Figure 2 The passive vibration isolation technology utilizes the characteristics of the quasi-zero stiffness mechanism 105. The nano-pan-tilt platform 101 achieves better dynamic vibration isolation performance while maintaining a high static load capacity. Figure 2 As can be seen in the figure, the addition of the quasi-zero stiffness mechanism 105 to the nano-pan-tilt platform 101 improves its resonance suppression and high-frequency vibration suppression performance. In summary, the addition of the quasi-zero stiffness mechanism 105 decouples the load-bearing capacity and vibration isolation performance of the nano-pan-tilt platform 101, while also addressing the drawback that increased damping would weaken the nano-pan-tilt platform 101's high-frequency vibration suppression characteristics.

[0053] Second embodiment

[0054] Figure 2 、 Figure 3 and Figure 4 A second embodiment of the present invention is shown, in which components that are identical to or corresponding to those in the first embodiment are marked with corresponding reference numerals to those in the first embodiment. For example, in the first embodiment, the nano-pan head with high static and low dynamic stiffness characteristics is marked with 101, and in the second embodiment, the nano-pan head with high static and low dynamic stiffness characteristics is marked with 201, and other components are similar.

[0055] like Figure 3 Specifically, the first mounting block 215 and the second mounting block 225 are arranged in a vertical direction; see Figure 4The positive stiffness mechanism 2135 includes four positive stiffness elastic members connected end to end, and the positive stiffness elastic members are connected and sequentially form a first intersection a2, a second intersection b2, a third intersection c2 and a fourth intersection d2. Each positive stiffness elastic member can rotate relative to the corresponding intersection. For example, one end of a positive stiffness elastic member is located at the first intersection a2, and the other end is located at the second intersection b2. The positive stiffness elastic member can rotate relative to the first intersection a2 and can also rotate relative to the second intersection b2 to avoid damage to the positive stiffness elastic member due to the rigid connection at the intersection when bearing load; the negative stiffness mechanism 2235 includes a negative stiffness elastic member, one end of the negative stiffness elastic member is connected to the first intersection a2, and the other end of the negative stiffness elastic member is connected to the third intersection c2. The line between the first intersection a2 and the third intersection c2 is parallel to the horizontal direction; the second intersection b2 is fixed to the first mounting block 215, and the fourth intersection d2 is fixed to the second mounting block 225.

[0056] See Figure 4 The principle of this structure is that the negative stiffness elastic member and the positive stiffness elastic member will deform at the same time. When the four positive stiffness elastic members are deformed, the direction of the resultant force formed by the four positive stiffness elastic members is roughly parallel to the vertical direction and opposite to the direction of the load applied by the output platform 203 to the first mounting block 215. Therefore, the positive stiffness elastic member can provide the first mounting block 215 with a supporting force in the vertical direction. Since the negative stiffness elastic members are connected in parallel at the diagonal line, the overall stiffness of the quasi-zero stiffness unit 235 will exhibit a "quasi-zero" characteristic. Specifically, the atomic force microscope probe 204 has high precision, and the displacement magnitude of the output platform 203 is at the nanometer level. Under the action of a small displacement load, the deformation of the quasi-zero stiffness unit 235 is almost negligible. This characteristic enables the quasi-zero stiffness mechanism 205 to have a more outstanding vibration reduction effect in a low-frequency vibration environment.

[0057] See Figure 4 This embodiment forms a 2x2 honeycomb cell linear array by connecting negative and positive elastic members in parallel. This honeycomb structure offers greater strength and stiffness than solid materials of equal weight, resulting in a quasi-zero-stiffness honeycomb structure with improved durability and longevity when subjected to shock and vibration.

[0058] See Figure 4 Furthermore, the line between the first intersection a2 and the third intersection c2 is perpendicular to the vertical direction, and the four positive stiffness elastic members are symmetrical with respect to the vertical direction, and the force is more uniform.

[0059] See Figure 4 Furthermore, the quasi-zero stiffness unit 235 is an integrated part, and the integrated processing eliminates the assembly gap between the moving pairs in the traditional rigid mechanism, thereby achieving a friction-free and lubrication-free working state.

[0060] It's important to emphasize that the honeycomb quasi-zero stiffness unit 235, based on the principle of parallel connection of positive and negative stiffness, is capable of achieving low-frequency, broadband vibration reduction. This means it effectively suppresses vibrations of all frequencies, particularly at low frequencies. Furthermore, despite its quasi-zero stiffness, the structure's load-bearing capacity remains unaffected, enabling the honeycomb quasi-zero stiffness unit 235 to maintain stable performance even under heavy loads.

[0061] See Figure 2 and Figure 3 When applied to the nano-pan-tilt platform 201, the drive assembly 208 drives the output platform 203 to move in the vertical direction, thereby driving the atomic force microscope probe 204 to move and adjust the distance between the atomic force microscope probe 204 and the observed object. The first mounting block 215 is fastened to the base frame 202 by screws, and the second mounting block 225 is fastened to the output platform 203 by screws. One or more honeycomb-shaped quasi-zero stiffness units 235 are provided between the first mounting block 215 and the second mounting block 225. The combination of the quasi-zero stiffness mechanism 205 and the nano-pan-tilt platform 201 with active / passive vibration suppression not only broadens the vibration isolation frequency band of the output platform 203, allowing the output platform 203 to exhibit good vibration isolation effects for vibrations of different frequencies, but also significantly improves the stability of the system through active and passive hybrid vibration isolation technology. Even in the event of active vibration isolation failure, the passive vibration isolation part, especially the honeycomb-shaped quasi-zero stiffness structure, can still effectively suppress vibration. Furthermore, the properties of the quasi-zero stiffness mechanism 205 and the highly customizable honeycomb structure allow for flexible adjustment of the stiffness of the nano-pan-tilt platform 201. Finally, the lightweight and high-strength nature of the honeycomb structure reduces overall weight while maintaining structural strength and stability, thereby improving energy efficiency and overall operational performance.

[0062] See Figure 3 Furthermore, the nano-stage 201 includes a hard spring member 207, one end of which is connected to the base frame 202 and the other end of which is connected to the output platform 203. The hard spring member 207 is used to apply a vertical elastic force to the output platform 203. The hard spring members 207 are symmetrically arranged on the left and right sides of the output platform 203. The hard spring members 207 can be coil springs, and the hard spring members 207 can offset the gravity of the output platform 203 and the atomic force microscope probe 204.

[0063] See Figure 3Furthermore, the nano-pan-tilt platform 201 further includes a flexible leaf spring 206. One end of the flexible leaf spring 206 is connected to the base frame 202, and the other end of the flexible leaf spring 206 is connected to the output platform 203. The flexible leaf spring 206 is used to apply a vertical elastic force to the output platform 203. Specifically, the flexible leaf spring 206 is an S-shaped spring and has greater flexibility than the hard spring 207. Therefore, the flexible leaf spring 206 can serve as a passive vibration isolation device for vibration reduction.

[0064] Third embodiment

[0065] Figure 2 、 Figure 5 and Figure 6 The third embodiment of the present invention is shown, in which the components that are identical or corresponding to those in the first and second embodiments are marked with corresponding figure marks. For example, in the first embodiment, the nano-pan-tilt with high static and low dynamic stiffness characteristics is marked as 101, in the second embodiment, the nano-pan-tilt with high static and low dynamic stiffness characteristics is marked as 201, and in the third embodiment, the nano-pan-tilt with high static and low dynamic stiffness characteristics is marked as 301. Other components are similar.

[0066] like Figure 5 Specifically, the first mounting block 315 and the second mounting block 325 are arranged in a vertical direction; see Figure 6 The quasi-zero stiffness unit 335 includes a frame 32135, and the frame 32135 includes four trusses connected end to end, and two adjacent trusses can be rotatably arranged. That is, the four trusses are connected end to end to form a closed quadrilateral, and the quadrilateral has four frame intersections and two diagonals. The two adjacent sides of the quadrilateral can rotate relative to the frame intersections. The first frame intersection a3 and the third frame intersection c3 are connected to form a diagonal, and the second frame intersection b3 and the fourth frame intersection d3 are connected to form another diagonal; the positive stiffness mechanism 3135 includes a positive stiffness elastic member, and the positive stiffness elastic member is provided at a diagonal of the frame 32135, that is, one of the positive stiffness elastic members. One end of the positive stiffness elastic member is hinged to the first frame intersection a3 of the frame 32135, and the other end of the positive stiffness elastic member is hinged to the third frame intersection c3 of the frame 32135. The first frame intersection a3 is connected to the first mounting block 315, and the third frame intersection c3 is connected to the second mounting block 325; the negative stiffness mechanism 3235 includes a negative stiffness elastic member, and the negative stiffness elastic member is arranged at the other diagonal line of the frame 32135, that is, one end of the negative stiffness elastic member is hinged to the second frame intersection b3 of the frame 32135, and the other end of the negative stiffness elastic member is hinged to the fourth frame intersection d3 of the frame 32135; the positive stiffness elastic member is parallel to the vertical direction, and the negative stiffness elastic member is parallel to the horizontal direction.

[0067] like Figure 6 As shown, the quasi-zero stiffness unit 335 of this embodiment is an X-shaped quasi-zero stiffness structure. By connecting the positive stiffness elastic member and the negative stiffness elastic member in parallel through the frame 32135, it is possible to achieve a lightweight design of the structure while ensuring the overall structural performance. This not only reduces material usage and production costs, but also improves the dynamic performance of the structure. In addition, this quasi-zero stiffness structure exhibits unique performance near the static equilibrium position: its dynamic stiffness is close to zero, while the static stiffness is maintained at a high level. This means that the structure exhibits a strong bearing capacity when subjected to static loads, and exhibits lower stiffness when facing dynamic loads, which is conducive to achieving vibration isolation and vibration reduction effects.

[0068] like Figure 6 As shown, the specific working principle is: this X-shaped structure connects a positive stiffness elastic member and a negative stiffness elastic member in parallel through the frame 32135. The positive stiffness elastic member is a vertically arranged spring, and the negative stiffness elastic member is a horizontally arranged spring. The two springs are arranged diagonally in the frame 32135, thereby constructing an overall structure with quasi-zero stiffness characteristics. When an external load acts on the quasi-zero stiffness mechanism 305, the horizontal spring and the vertical spring will deform simultaneously. Figure 2 As shown, the presence of the horizontal spring as negative stiffness mechanism 3135 makes the overall stiffness of the structure exhibit a "quasi-zero" characteristic, that is, under small loads, the deformation of the structure is almost negligible. This characteristic makes the X-shaped quasi-zero stiffness mechanism 305 have an excellent vibration reduction effect in low-frequency vibration environments.

[0069] like Figure 6 As shown, when applied to a nano-pan-tilt head 301, the first mounting block 315 is fastened to the base frame 302 via screws, and the second mounting block 325 is fastened to the output platform 303 via screws. A drive assembly 308 drives the output platform 303 to move vertically, thereby moving the AFM probe 304 to adjust the distance between the AFM probe 304 and the object being observed. One or more X-shaped quasi-zero stiffness mechanisms 305 are positioned between the first mounting block 315 and the second mounting block 325. The combination of the quasi-zero stiffness mechanisms 305 with the nano-pan-tilt head, which integrates active and passive vibration suppression, not only broadens the vibration isolation frequency band of the output platform 303, enabling the output platform 303 to exhibit excellent vibration isolation effects for vibrations of varying frequencies, but also significantly improves system stability through the hybrid active and passive vibration isolation technology. Even if active vibration isolation fails, the passive vibration isolation component, particularly the X-shaped quasi-zero stiffness mechanisms 305, can still effectively suppress vibrations.

[0070] like Figure 6As shown, further, different diagonals of frame 32135 intersect to form a fifth frame intersection e3. Two positive springs are provided, one between the first frame intersection a3 and the fifth frame intersection e3, and the other between the third frame intersection c3 and the fifth frame intersection e3. Two negative springs are provided, one between the second frame intersection b3 and the fifth frame intersection e3, and the other between the fourth frame intersection d3 and the fifth frame intersection e3. Accordingly, each positive spring can rotate relative to the fifth frame intersection e3, and each negative spring can rotate relative to the fifth frame intersection e3.

[0071] like Figure 6 As shown, the nano-stage 301 with high static and low dynamic stiffness further includes a hard spring member 307. One end of the hard spring member 307 is connected to the base frame 302, and the other end of the hard spring member 307 is connected to the output platform 303. The hard spring member 307 is used to apply a vertical elastic force to the output platform 303. The hard spring members 307 are symmetrically arranged on the left and right sides of the output platform 303. The hard spring members 307 can be coil springs. The hard spring members 307 can offset the gravity of the output platform 303 and the atomic force microscope probe 304.

[0072] Furthermore, the nano-pan-tilt platform 301, which exhibits high static and low dynamic stiffness, also includes a flexible leaf spring 306. One end of the flexible leaf spring 306 is connected to the base frame 302, and the other end is connected to the output platform 303. The flexible leaf spring 306 is used to apply a vertical elastic force to the output platform 303. Specifically, the flexible leaf spring 306 is an S-shaped spring and has greater flexibility than the hard spring 307. Therefore, the flexible leaf spring 306 can function as a passive vibration isolation device for vibration reduction.

[0073] Fourth embodiment

[0074] Figure 2 、 Figure 7 and Figure 8 The fourth embodiment of the present invention is shown, in which the components that are identical or corresponding to those in the first, second and third embodiments are marked with corresponding figure marks of the first, second and third embodiments. For example, in the first embodiment, the figure mark of the nano-pan-tilt with high static and low dynamic stiffness characteristics is 101, in the second embodiment, the figure mark of the nano-pan-tilt with high static and low dynamic stiffness characteristics is 201, in the third embodiment, the figure mark of the nano-pan-tilt with high static and low dynamic stiffness characteristics is 301, and in the fourth embodiment, the figure mark of the nano-pan-tilt with high static and low dynamic stiffness characteristics is 401, and other components are similar.

[0075] like Figure 7As shown, further, the first mounting block 415 and the second mounting block 425 are arranged in a horizontal direction; see Figure 8 The positive stiffness mechanism 4135 includes a flexible leaf spring member 406, one end of the flexible leaf spring member 406 is connected to the first mounting block 415, and the other end of the flexible leaf spring member 406 is connected to the second mounting block 425. The flexible leaf spring member 406 deflects and deforms to apply an elastic force in the vertical direction; the negative stiffness mechanism 4235 includes a horizontally arranged negative stiffness elastic member, one end of which is connected to the first mounting block 415, and the other end of which is connected to the second mounting block 425. The negative stiffness elastic member is arranged parallel to the horizontal direction.

[0076] like Figure 7 As shown, specifically, the quasi-zero stiffness mechanism 405 includes two, the second mounting block 425 of one quasi-zero stiffness mechanism 405 is fixed on the left side of the output platform 403, and its first mounting block 415 is fixed on the left side of the base and arranged horizontally with the second mounting block 425; the second mounting block 425 of the other quasi-zero stiffness mechanism 405 is fixed on the right side of the output platform 403, and its first mounting block 415 is fixed on the right side of the base and arranged horizontally with the second mounting block 425.

[0077] like Figure 7 and Figure 8 As shown, when used in a nano-pan-tilt head 401 with high static and low dynamic stiffness, the first mounting block 415 is fastened to the base frame 402 via screws, and the second mounting block 425 is fastened to the output platform 403 via screws. The drive assembly 408 drives the output platform 403 to move vertically, thereby moving the atomic force microscope probe 404 to adjust the distance between the atomic force microscope probe 404 and the observed object. The flexible leaf spring member 406 is designed using a leaf spring hinge connected end to end in series. Multiple leaf springs are arranged in a generally horizontal direction. The flexible leaf spring member 406 deflects and deforms to apply a vertical elastic force, thereby improving the load-bearing capacity. The flexible leaf spring member 406 with positive stiffness characteristics is combined in parallel with a negative stiffness elastic member with negative stiffness characteristics, thereby achieving a dynamic stiffness close to or equal to zero in the static equilibrium position. The rational combination of the positive stiffness mechanism 4135 and the negative stiffness mechanism 4235 can achieve a lightweight design while ensuring overall structural performance.

[0078] The flexible leaf spring member 406 can be processed in an integrated manner, requiring only a small amount of assembly, thereby reducing production costs. The design of the leaf spring hinge in series utilizes the deformation of the flexible leaf spring member 406 to achieve movement and force transmission, rather than simply relying on rigid connections, which reduces unnecessary material usage.

[0079] The difference between this embodiment and the above-mentioned embodiment 2 and embodiment 3 is that the flexible leaf spring member 306 in the above-mentioned embodiment 2 and embodiment 3 is incorporated into the quasi-zero stiffness unit 435, instead of being separately arranged between the output platform 403 and the base frame 402. This helps to reduce material consumption and production costs, while improving the dynamic performance of the structure.

[0080] like Figure 7 As shown, nano-stage 401 further includes a hard spring member 407, one end of which is connected to base frame 402, and the other end of which is connected to output platform 403. Hard spring member 407 is used to apply a vertical elastic force to output platform 403. Hard spring member 407 is symmetrically arranged on the left and right sides of output platform 403. Hard spring member 407 can be a coil spring, and hard spring member 407 can offset the gravity of output platform 403 and atomic force microscope probe 404.

[0081] Fifth embodiment

[0082] Figure 2 、 Figure 9 and Figure 10 The fifth embodiment of the present invention is shown, in which the components that are identical or corresponding to those in the first, second, third and fourth embodiments are marked with corresponding figure marks of the first, second, third and fourth embodiments. For example, in the first embodiment, the figure mark of the nano-pan-tilt with high static and low dynamic stiffness characteristics is 101, in the second embodiment, the figure mark of the nano-pan-tilt with high static and low dynamic stiffness characteristics is 201, in the third embodiment, the figure mark of the nano-pan-tilt with high static and low dynamic stiffness characteristics is 301, in the fourth embodiment, the figure mark of the nano-pan-tilt with high static and low dynamic stiffness characteristics is 401, and in the fifth embodiment, the figure mark of the nano-pan-tilt with high static and low dynamic stiffness characteristics is 501, and other components are similar.

[0083] like Figure 9 As shown, further, the first mounting block 515 and the second mounting block 525 are arranged in a vertical direction; see Figure 10The first mounting block 515 has a mounting groove 5515, and the second mounting block 525 is movably arranged in the mounting groove 5515 along the vertical direction; the positive stiffness mechanism 5135 includes a positive stiffness elastic member, one end of the positive stiffness elastic member is connected to the bottom wall of the mounting groove 5515, and the other end of the positive stiffness elastic member is connected to the top wall of the second mounting block 525; the negative stiffness mechanism 5235 includes a negative stiffness elastic member, and there are multiple negative stiffness elastic members arranged at intervals around the first mounting block 515, one end of each negative stiffness elastic member is connected to the groove peripheral wall of the mounting groove 5515, and the other end of each negative stiffness elastic member is on the side peripheral wall of the second mounting block 525; the extension lines of the negative stiffness elastic members intersect with the straight line where the positive stiffness elastic member is located.

[0084] See Figure 10 When applied to the nano pan-tilt head 501, the first mounting block 515 is fastened to the base frame 502 by screws, and the second mounting block 525 is fastened to the output platform 503 by screws. The driving component 508 drives the output platform 503 to move in the vertical direction, thereby driving the atomic force microscope probe 504 to move to adjust the distance between the atomic force microscope probe 504 and the observed object.

[0085] See Figure 10 In this embodiment, the quasi-zero stiffness unit 435 constructs an overall structure with quasi-zero stiffness characteristics by combining symmetrically arranged negative stiffness elastic members as negative stiffness mechanisms 5235 and vertically arranged positive stiffness elastic members as positive stiffness mechanisms 5135 in parallel. The principle of this structure is as follows: the vertically arranged positive stiffness elastic members are used to support the output platform 503 and the atomic force microscope probe 504, and the horizontally arranged negative stiffness elastic members are used to offset the stiffness of the positive stiffness compression springs, so that the stiffness of the output platform 503 at the static equilibrium position tends to zero. This quasi-zero stiffness mechanism 505 has high static stiffness and low dynamic stiffness characteristics. The high static stiffness improves the load-bearing capacity of the quasi-zero stiffness structure and reduces static displacement; the low dynamic stiffness reduces the natural frequency of the output platform 503, resulting in a wider vibration isolation frequency band than that of a linear vibration isolator.

[0086] See Figure 9 Furthermore, the nano-stage 501 includes a hard spring member 507, one end of which is connected to the base frame 502 and the other end of which is connected to the output platform 503. The hard spring member 507 is used to apply a vertical elastic force to the output platform 503. The hard spring members 507 are symmetrically arranged on the left and right sides of the output platform 503. The hard spring members 507 can be coil springs, and the hard spring members 507 can offset the gravity of the output platform 503 and the atomic force microscope probe 504.

[0087] See Figure 9Furthermore, the nano-pan-tilt platform 501 further includes a flexible leaf spring 506. One end of the flexible leaf spring 506 is connected to the base frame 502, and the other end of the flexible leaf spring 506 is connected to the output platform 503. The flexible leaf spring 506 is used to apply a vertical elastic force to the output platform 503. Specifically, the flexible leaf spring 506 is an S-shaped spring and has greater flexibility than the hard spring 507. The flexible leaf spring 506 can serve as a passive vibration isolation device to reduce vibration.

[0088] The other components and operations of the nano-pan-tilt platform with high static and low dynamic stiffness according to the embodiments of the present invention are well known to those skilled in the art and will not be described in detail here. In the description of the present invention, "first feature" and "second feature" may include one or more of these features. The up-down direction, left-right direction, and front-back direction are based on the up-down direction, left-right direction, and front-back direction shown in the figure.

[0089] In the description of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or the first and second features being in contact not directly but through another feature therebetween. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is at a higher level than the second feature.

[0090] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0091] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A nano-pan-tilt platform with high static and low dynamic stiffness, characterized in that: include: scaffolding; An output platform, the output platform is movably mounted on the base frame in a vertical direction; an atomic force microscope probe, wherein the atomic force microscope probe is mounted on the output platform; A quasi-zero stiffness mechanism, comprising a first mounting block, a second mounting block, and a quasi-zero stiffness unit, wherein the quasi-zero stiffness unit is mounted between the first mounting block and the second mounting block, the first mounting block is used to connect to the base frame, and the second mounting block is used to connect to the output platform; The quasi-zero stiffness unit includes a positive stiffness mechanism and a negative stiffness mechanism, wherein the positive stiffness mechanism is used to apply a supporting force to the output platform, and the negative stiffness mechanism is arranged in the horizontal direction and is configured to offset the stiffness of the positive stiffness mechanism in the vertical direction when the positive stiffness mechanism applies the supporting force to the output platform; The quasi-zero stiffness unit meets one of the following conditions: Condition 1: The first mounting block and the second mounting block are arranged in parallel along the vertical direction; The positive stiffness mechanism includes four positive stiffness elastic members connected end to end, the positive stiffness elastic members are connected and sequentially form a first intersection point, a second intersection point, a third intersection point and a fourth intersection point, and each of the positive stiffness elastic members is configured to rotate relative to an intersection point; The negative stiffness mechanism includes a negative stiffness elastic member, one end of the negative stiffness elastic member is connected to the first intersection, the other end of the negative stiffness elastic member is connected to the third intersection, and the line between the first intersection and the third intersection is parallel to the horizontal direction; the second intersection is provided on the first mounting block, the fourth intersection is provided on the second mounting block, and the line between the second intersection and the fourth intersection is parallel to the vertical direction; Condition 2: The first mounting block and the second mounting block are arranged in parallel along the horizontal direction; The positive stiffness mechanism includes a flexible leaf spring member, one end of the flexible leaf spring member is connected to the first mounting block, the other end of the flexible leaf spring member is connected to the second mounting block, and the flexible leaf spring member deflects and deforms to apply an elastic force in the vertical direction; The negative stiffness mechanism includes a negative stiffness elastic member, one end of which is connected to the first mounting block and the other end of which is connected to the second mounting block; Condition 3: The first mounting block and the second mounting block are arranged in parallel along the vertical direction; The first mounting block has a mounting groove therein, and the second mounting block is movably arranged in the mounting groove along a vertical direction; The positive stiffness mechanism includes a positive stiffness elastic member, one end of which is connected to the bottom wall of the mounting slot, and the other end of which is connected to the top wall of the second mounting block, wherein the bottom wall and the top wall are arranged opposite to each other in the vertical direction; The negative stiffness mechanism includes a negative stiffness elastic member, a plurality of which are spaced apart and arranged around the first mounting block, one end of each of the negative stiffness elastic members being connected to the groove peripheral wall of the mounting groove, and the other end of each of the negative stiffness elastic members being connected to the side peripheral wall of the second mounting block, the groove peripheral wall and the side peripheral wall being arranged opposite to each other in the horizontal direction; The extension line of the negative stiffness elastic member intersects with the straight line where the positive stiffness elastic member is located.

2. The nano-pan-tilt platform with high static and low dynamic stiffness according to claim 1, characterized in that: In the quasi-zero stiffness unit in condition 1, the quasi-zero stiffness unit is a one-piece piece.

3. The nano-pan-tilt platform with high static and low dynamic stiffness according to claim 1, characterized in that: In the quasi-zero stiffness unit in Condition 1 and Condition 3, the nano-pan head further includes a flexible leaf spring member, one end of which is connected to the base frame, and the other end of which is connected to the output platform, and the flexible leaf spring member is used to apply an elastic force in the vertical direction to the output platform.

4. The nano-pan-tilt platform with high static and low dynamic stiffness according to claim 1, characterized in that: It also includes a hard spring component, one end of which is connected to the base frame, and the other end of which is connected to the output platform. The hard spring component is used to apply elastic force in the vertical direction to the output platform.

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