High-precision three-degree-of-freedom piezoelectric scanning table

Abstract

The invention relates to the technical field of precise positioning tables, and discloses a high-precision three-degree-of-freedom piezoelectric scanning table which comprises a flexible hinge structure. The flexible hinge structure is provided with an X-axis piezoelectric driving mechanism, a Y-axis piezoelectric driving mechanism and a Z-axis piezoelectric driving mechanism. The flexible hinge structure sequentially comprises a first annular part, a second annular part and a third annular part from inside to outside. And the X-axis piezoelectric driving mechanism is connected with the first annular part and the second annular part. And the Y-axis piezoelectric driving mechanism is connected with the second annular part and the third annular part. The Z-axis piezoelectric driving mechanism is arranged on the first annular part, and the moving end of the Z-axis piezoelectric driving mechanism is connected with the moving face. A plurality of X-axis amplification piezoelectric actuators, Y-axis amplification piezoelectric actuators and Z-axis amplification piezoelectric actuators are connected in series, so that a moving surface can linearly move in the X axis, the Y axis and the Z axis, and three-dimensional ultra-precise nanoscale positioning is realized. The whole series connection structure is small in motion coupling, high in precision, good in straightness and high in scanning flatness.

Description

Technical Field

[0001] The present invention belongs to the technical field of precision positioning stages, and in particular relates to a high-precision three-degree-of-freedom piezoelectric scanning stage. Background Art

[0002] In recent years, micro-nanotechnology has experienced rapid development and widespread application. Research and development in this field relies on nanometer-precision actuation, positioning, displacement measurement, and related processing technologies and equipment. With the advancement of nanotechnology, the development of proprietary intellectual property rights for nanometer-precision stepping displacement positioning, high-precision nano-actuation, and positioning devices has become increasingly important and has significant application implications.

[0003] Piezoelectric ceramic tubes (PZTs), with their nanometer-scale movement steps, fast response speed, suitable scanning range, and compact structure, are ideal materials for studying nanomotion. Piezoelectric ceramics are particularly popular as actuators in instruments such as scanning probe microscopes (SPMs). However, existing piezoelectric scanning stages suffer from significant kinematic coupling, low repeatability, poor scanning smoothness, limited travel range, and bulky design.

[0004] Based on the above, the current problem to be solved is to provide a high-precision three-degree-of-freedom piezoelectric scanning stage that can achieve three-dimensional motion in the X-axis, Y-axis, and Z-axis, with small motion coupling, high repeatability, large stroke, and compact structure. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-precision three-degree-of-freedom piezoelectric scanning stage, aiming to solve the problems of large motion coupling, low repeatability, small stroke, large size and poor scanning flatness of the piezoelectric scanning stage in the prior art.

[0006] The present invention is achieved by providing a high-precision three-degree-of-freedom piezoelectric scanning stage, comprising a moving surface, an upper cover, an outer shell, and a bottom cover, wherein the moving surface, the upper cover, the outer shell, and the bottom cover form an accommodating cavity, wherein a flexible hinge structure connected to the outer shell is provided in the accommodating cavity, and an X-axis piezoelectric drive mechanism, a Y-axis piezoelectric drive mechanism, and a Z-axis piezoelectric drive mechanism are provided on the flexible hinge structure;

[0007] The flexible hinge structure includes, from the inside out, a first annular portion, a second annular portion, and a third annular portion, wherein the first annular portion and the second annular portion are connected by a first flexible hinge arm, and the second annular portion and the third annular portion are connected by a second flexible hinge arm;

[0008] The X-axis piezoelectric drive mechanism is connected to the first annular portion and the second annular portion; the Y-axis piezoelectric drive mechanism is connected to the second annular portion and the third annular portion; the Z-axis piezoelectric drive mechanism is arranged on the first annular portion, and the moving end of the Z-axis piezoelectric drive mechanism is connected to the moving surface.

[0009] Furthermore, two of the X-axis piezoelectric drive mechanisms and two of the Y-axis piezoelectric drive mechanisms are provided; the two X-axis piezoelectric drive mechanisms are provided symmetrically with the Y-axis as the center axis, and the two Y-axis piezoelectric drive mechanisms are provided symmetrically with the X-axis as the center axis.

[0010] Furthermore, four Z-axis piezoelectric drive mechanisms are provided, and the Z-axis piezoelectric drive mechanisms are arranged in groups of two and are symmetrically arranged with the X-axis as the center.

[0011] Furthermore, the X-axis piezoelectric drive mechanism includes a first quadrilateral enlarging body and a first piezoelectric ceramic arranged in the first quadrilateral enlarging body; the movable end and the fixed end of the first quadrilateral enlarging body are respectively connected to the first annular portion and the second annular portion; the first piezoelectric ceramic is arranged parallel to the Y-axis, and the first flexible hinge arm is arranged parallel to the Y-axis.

[0012] Furthermore, the Y-axis piezoelectric drive mechanism includes a second quadrilateral enlarging body and a second piezoelectric ceramic arranged in the second quadrilateral enlarging body; the movable end and the fixed end of the second quadrilateral enlarging body are respectively connected to the second annular portion and the third annular portion; the second piezoelectric ceramic is arranged parallel to the X-axis, and the second flexible hinge arm is arranged parallel to the X-axis.

[0013] Furthermore, the Z-axis piezoelectric drive mechanism includes a rectangular magnifying body and a third piezoelectric ceramic arranged in the rectangular magnifying body, the third piezoelectric ceramic is arranged parallel to the X-axis, the rectangular magnifying body is provided with 4 third flexible hinge arms, and the third flexible hinge arms are symmetrically arranged in groups of two on the upper and lower sides of the third piezoelectric ceramic.

[0014] Furthermore, a strain sensor is provided on the outer side surface of the third flexible hinge arm.

[0015] Furthermore, a strain sensor is provided on the side of the first flexible hinge arm and / or the second flexible hinge arm.

[0016] Furthermore, the flexible hinge structure is configured as a wire-cut flexure hinge structure optimized by finite element analysis.

[0017] Furthermore, the movable surface is provided with a through hole for light transmission.

[0018] The high-precision three-degree-of-freedom piezoelectric scanning stage of the present invention utilizes multiple X-axis, Y-axis, and Z-axis amplifying piezoelectric actuators connected in series, enabling linear motion of the moving surface along the X, Y, and Z axes, achieving three-dimensional ultra-precision nanometer-scale positioning. Furthermore, the series structure minimizes kinematic coupling, resulting in high accuracy, excellent linearity, and high scanning smoothness. Each axis utilizes multiple piezoelectric actuators, each employing an amplifying structure, resulting in a large output stroke.

[0019] The first, second, and third annular sections of the flexible hinge structure are connected in series from the inside out and integrated into one unit. This minimizes kinematic coupling between the X-axis, Y-axis, and Z-axis piezoelectric drive mechanisms, resulting in highly accurate repeatable positioning, fast response, and a compact structure. Furthermore, the flexible hinge structure utilizes a wire-cut flexure hinge optimized using finite element analysis (FEA), resulting in enhanced rigidity and minimal linear and angular motion.

[0020] The present invention can use a strain sensor. The strain sensor performs real-time detection and feedback of the position, which can eliminate the hysteresis and creep characteristics of piezoelectric ceramics and achieve nanometer-level precision positioning control. The closed-loop version of the present invention has higher repeatability and is suitable for various high-precision application scenarios. The center of the high-precision three-degree-of-freedom piezoelectric scanning stage is provided with a light-transmitting through-hole, so it can be used in scenarios such as near-field scanning, confocal microscopy, and mask positioning, and has strong functionality. The overall structure of the present invention is reasonable, compact, and small in size, making it easy to install in other application systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the three-dimensional structure of the high-precision three-degree-of-freedom piezoelectric scanning stage provided by the present invention;

[0022] Figure 2 This is an exploded view of the high-precision three-degree-of-freedom piezoelectric scanning stage provided by the present invention;

[0023] Figure 3 A top view of the X-axis piezoelectric drive mechanism, Y-axis piezoelectric drive mechanism, Z-axis piezoelectric drive mechanism, flexible hinge structure, and housing assembly provided by the present invention;

[0024] Figure 4 A schematic diagram of the three-dimensional structure of the X-axis piezoelectric drive mechanism provided by the present invention;

[0025] Figure 5 A front view of the Z-axis piezoelectric drive mechanism provided by the present invention;

[0026] Figure 6 is a top view of the flexible hinge structure and housing combination provided by the present invention;

[0027] In the figure: 1-moving surface; 11-through hole; 2-upper cover; 3-housing; 4-bottom cover; 5-accommodating cavity; 6-flexible hinge structure; 61-first annular portion; 62-second annular portion; 63-third annular portion; 64-first flexible hinge arm; 65-second flexible hinge arm; 7-X-axis piezoelectric drive mechanism; 71-first quadrilateral magnifying body; 72-first piezoelectric ceramic; 8-Y-axis piezoelectric drive mechanism; 81-second quadrilateral magnifying body; 82-second piezoelectric ceramic; 9-Z-axis piezoelectric drive mechanism; 91-rectangular magnifying body; 911-third flexible hinge arm; 92-third piezoelectric ceramic; 10-strain sensor. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] The implementation of the present invention is described in detail below with reference to specific embodiments.

[0030] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "up", "down", "left", "right", etc. indicate directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0031] Reference Figure 1-6 The figure shows a preferred embodiment of the present invention.

[0032] The high-precision three-degree-of-freedom piezoelectric scanning platform includes a moving surface 1, an upper cover 2, a shell 3 and a bottom cover 4. Figure 1 The moving surface 1, the upper cover 2, the outer shell 3 and the bottom cover 4 form a receiving cavity 5. The moving surface 1 is provided with a through hole 11 for light transmission, which is suitable for near-field scanning, confocal microscopy and mask positioning. The receiving cavity 5 is provided with a flexible hinge structure 6, an X-axis piezoelectric drive mechanism 7, a Y-axis piezoelectric drive mechanism 8 and a Z-axis piezoelectric drive mechanism 9. Figure 2 The flexible hinge structure 6 is connected to the housing 3 and is arranged at the bottom of the housing 3. Preferably, the flexible hinge structure 6 and the housing 3 are integrally formed. The X-axis piezoelectric drive mechanism 7, the Y-axis piezoelectric drive mechanism 8 and the Z-axis piezoelectric drive mechanism 9 are laid flat on the flexible hinge structure 6 and fixed by bolts. Figure 3 .

[0033] The flexible hinge structure 6 includes a first annular portion 61, a second annular portion 62 and a third annular portion 63 from the inside out. Figure 6 The first annular portion 61 and the second annular portion 62 are connected by a first flexible hinge arm 64. The second annular portion 62 and the third annular portion 63 are connected by a second flexible hinge arm 65. The flexible hinge structure 6 utilizes a wire-cut flexure hinge structure optimized by finite element analysis (FEA). This structure has improved rigidity and minimizes linear and angular motion.

[0034] The movable end and the fixed end of the X-axis piezoelectric drive mechanism 7 are arranged at the bottom. The movable end of the X-axis piezoelectric drive mechanism 7 is connected to the first annular portion 61, and the fixed end of the X-axis piezoelectric drive mechanism 7 is connected to the second annular portion 62. The movable end and the fixed end of the Y-axis piezoelectric drive mechanism 8 are arranged at the bottom. The movable end of the Y-axis piezoelectric drive mechanism 8 is connected to the second annular portion 62, and the fixed end of the Y-axis piezoelectric drive mechanism 8 is connected to the third annular portion 63. The fixed end of the Z-axis piezoelectric drive mechanism 9 is arranged at the bottom, and the movable end is arranged at the top. The fixed end of the Z-axis piezoelectric drive mechanism 9 is connected to the first annular portion 61, and the movable end of the Z-axis piezoelectric drive mechanism 9 is connected to the movable surface 1. The Z-axis piezoelectric drive mechanism 9 pushes the movable surface 1 to move linearly along the Z-axis. The X-axis piezoelectric drive mechanism 7 pushes the first annular portion 61, and the first annular portion 61 drives the Z-axis piezoelectric drive mechanism 9 and the movable surface 1 to move linearly along the X-axis. The Y-axis piezoelectric drive mechanism 8 pushes the second annular portion 62, which in turn drives the first annular portion 61, thereby pushing the moving surface 1 to move linearly along the Y-axis. The present invention achieves ultra-precise nano-positioning along the X-axis, Y-axis, and Z-axis with very high straightness.

[0035] Two X-axis piezoelectric drive mechanisms 7 and two Y-axis piezoelectric drive mechanisms 8 are provided. The two X-axis piezoelectric drive mechanisms 7 are symmetrically arranged with the Y-axis as the center axis, and are respectively used to push the moving surface 1 to move linearly along the positive direction of the X-axis and the negative direction of the X-axis. The two Y-axis piezoelectric drive mechanisms 8 are symmetrically arranged with the X-axis as the center axis, and are respectively used to push the moving surface 1 to move linearly along the positive direction of the Y-axis and the negative direction of the Y-axis. Four Z-axis piezoelectric drive mechanisms 9 are provided. The Z-axis piezoelectric drive mechanisms 9 are arranged in groups of two with the X-axis as the center axis. The four Z-axis piezoelectric drive mechanisms 9 jointly push the moving surface 1 to move linearly along the Z-axis, with a large output and uniform force on the moving surface 1.

[0036] The preferred embodiment of the X-axis piezoelectric drive mechanism 7 includes a first quadrilateral amplifying body 71 and a first piezoelectric ceramic 72 disposed in the first quadrilateral amplifying body 71. The movable end of the first quadrilateral amplifying body 71 is connected to the first annular portion 61, and the fixed end of the first quadrilateral amplifying body 71 is connected to the second annular portion 62. Figure 4 The first piezoelectric ceramic 72 is arranged parallel to the Y axis and outputs displacement in a direction parallel to the X axis. The first flexible hinge arm 64 is arranged parallel to the Y axis.

[0037] The preferred embodiment of the Y-axis piezoelectric drive mechanism 8 includes a second quadrilateral amplifying body 81 and a second piezoelectric ceramic 82 disposed within the second quadrilateral amplifying body 81. The movable end of the second quadrilateral amplifying body 81 is connected to the second annular portion 62. The fixed end of the second quadrilateral amplifying body 81 is connected to the third annular portion 63. The second piezoelectric ceramic 82 is positioned parallel to the X-axis and outputs displacement in a direction parallel to the Y-axis. The second flexible hinge is positioned parallel to the X-axis.

[0038] The preferred embodiment of the Z-axis piezoelectric drive mechanism 9 includes a rectangular enlarged body 91 and a third piezoelectric ceramic 92 disposed in the rectangular enlarged body 91. Figure 5 The third piezoelectric ceramic 92 is arranged parallel to the X-axis and outputs displacement in the direction parallel to the Z-axis. The rectangular enlarged body 91 is provided with four third flexible hinge arms 911, which are symmetrically arranged in pairs on the upper and lower sides of the third piezoelectric ceramic 92.

[0039] Preferably, a strain sensor 10 is provided on the outer side of the third flexible hinge arm 911. Strain sensors 10 are also provided on the side surfaces of the first flexible hinge arm 64 and / or the second flexible hinge arm 65. The strain sensor 10 eliminates the hysteresis and creep characteristics of piezoelectric ceramics, provides real-time position detection and feedback, and enables nanometer-level precision positioning control.

[0040] This does not limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-precision three-degree-of-freedom piezoelectric scanning platform, comprising a moving surface (1), an upper cover (2), an outer shell (3) and a bottom cover (4), wherein the moving surface (1), the upper cover (2), the outer shell (3) and the bottom cover (4) form a receiving cavity (5), characterized in that: A flexible hinge structure (6) connected to the housing (3) is provided in the accommodating cavity (5), and an X-axis piezoelectric drive mechanism (7), a Y-axis piezoelectric drive mechanism (8), and a Z-axis piezoelectric drive mechanism (9) are provided on the flexible hinge structure (6); The flexible hinge structure (6) includes, from the inside out, a first annular portion (61), a second annular portion (62), and a third annular portion (63); the first annular portion (61) and the second annular portion (62) are connected by providing a first flexible hinge arm (64); the second annular portion (62) and the third annular portion (63) are connected by providing a second flexible hinge arm (65); The X-axis piezoelectric drive mechanism (7) is connected to the first annular portion (61) and the second annular portion (62); the Y-axis piezoelectric drive mechanism (8) is connected to the second annular portion (62) and the third annular portion (63); the Z-axis piezoelectric drive mechanism (9) is provided on the first annular portion (61), and the moving end of the Z-axis piezoelectric drive mechanism (9) is connected to the moving surface (1).

2. The high-precision three-degree-of-freedom piezoelectric scanning stage according to claim 1, characterized in that: Two of the X-axis piezoelectric drive mechanisms (7) and two of the Y-axis piezoelectric drive mechanisms (8) are provided; the two X-axis piezoelectric drive mechanisms (7) are provided symmetrically with the Y-axis as the center axis, and the two Y-axis piezoelectric drive mechanisms (8) are provided symmetrically with the X-axis as the center axis.

3. The high-precision three-degree-of-freedom piezoelectric scanning stage according to claim 1, characterized in that: Four Z-axis piezoelectric drive mechanisms (9) are provided, and the Z-axis piezoelectric drive mechanisms (9) are arranged in groups of two in a symmetrical manner with the X-axis as the center.

4. The high-precision three-degree-of-freedom piezoelectric scanning stage according to claim 1, characterized in that: The X-axis piezoelectric drive mechanism (7) includes a first quadrilateral magnifying body (71) and a first piezoelectric ceramic (72) arranged in the first quadrilateral magnifying body (71); the movable end and the fixed end of the first quadrilateral magnifying body (71) are respectively connected to the first annular portion (61) and the second annular portion (62); the first piezoelectric ceramic (72) is arranged parallel to the Y-axis, and the first flexible hinge arm (64) is arranged parallel to the Y-axis.

5. The high-precision three-degree-of-freedom piezoelectric scanning stage according to claim 1, characterized in that: The Y-axis piezoelectric drive mechanism (8) includes a second quadrilateral magnifying body (81) and a second piezoelectric ceramic (82) arranged in the second quadrilateral magnifying body (81); the movable end and the fixed end of the second quadrilateral magnifying body (81) are respectively connected to the second annular portion (62) and the third annular portion (63); the second piezoelectric ceramic (82) is arranged parallel to the X-axis, and the second flexible hinge arm (65) is arranged parallel to the X-axis.

6. The high-precision three-degree-of-freedom piezoelectric scanning stage according to claim 1, characterized in that: The Z-axis piezoelectric drive mechanism (9) comprises a rectangular magnifying body (91) and a third piezoelectric ceramic (92) arranged in the rectangular magnifying body (91), wherein the third piezoelectric ceramic (92) is arranged parallel to the X-axis, and the rectangular magnifying body (91) is provided with four third flexible hinge arms (911), wherein the third flexible hinge arms (911) are symmetrically arranged in groups of two on the upper and lower sides of the third piezoelectric ceramic (92).

7. The high-precision three-degree-of-freedom piezoelectric scanning platform according to claim 6, wherein a strain sensor (10) is provided on the outer side surface of the third flexible hinge arm (911).

8. The high-precision three-degree-of-freedom piezoelectric scanning stage according to claim 1, characterized in that: A strain sensor (10) is provided on the side of the first flexible hinge arm (64) and / or the second flexible hinge arm (65).

9. The high-precision three-degree-of-freedom piezoelectric scanning stage according to claim 1, characterized in that: The flexible hinge structure (6) is set as a wire-cut flexure hinge structure optimized by finite element analysis.

10. The high-precision three-degree-of-freedom piezoelectric scanning stage according to claim 1, characterized in that: The moving surface (1) is provided with a through hole (11) for light transmission.

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