Flexible electrode structure and piezoelectric driving device

Abstract

The invention provides a flexible electrode structure and a piezoelectric driving device. The flexible electrode structure comprises a flexible electrode slice body. The flexible electrode plate body is provided with at least one of a first through groove and a second through groove, namely, the structure can comprise the first through groove or the second through groove, or the first through groove and the second through groove exist at the same time. The first through groove is completely formed in the outline of the flexible electrode plate body, and the whole first through groove does not exceed the boundary of the electrode plate body; and at least one part of the second through groove is configured to intersect with the outline of the flexible electrode plate body, namely, the structure of the second through groove extends to the edge of the electrode plate body or forms an opening. When the piezoelectric device works and causes the flexible electrode plate body to extend or contract, the first through groove and / or the second through groove can generate adaptive deformation accordingly, stress in the electrode plate body is effectively released through opening and closing or form change of the groove structure, and therefore the flexibility and durability of the electrode in the cyclic deformation process are improved.

Description

Technical Field

[0001] This application belongs to the field of piezoelectric actuator technology, and more specifically, relates to a flexible electrode structure and a piezoelectric actuator. Background Technology

[0002] Piezoelectric actuators rely on the inverse piezoelectric effect to frequently generate minute deformations during operation to achieve precise driving and positioning; this periodic strain is the basis for their normal operation. However, it is precisely this continuous alternating load that poses a severe challenge to the external electrodes attached to the surface of the piezoelectric material.

[0003] Conventional external electrode structures, such as directly deposited metal films or bonded sheet electrodes, have limited flexibility and poor matching with piezoelectric materials in terms of thermal expansion coefficients and deformation capabilities, making it difficult to fully follow the dynamic deformation of piezoelectric elements. This incompatibility leads to the accumulation of significant cyclic stress within the electrode material, resulting in insufficient ability to alleviate fatigue loads from the piezoelectric body.

[0004] Under prolonged exposure, microcracks can easily appear in the electrode layer and propagate, eventually leading to fatigue failure issues such as electrode breakage and peeling off from the piezoelectric surface. Simultaneously, the solder joints connecting the electrodes to external leads become weak points due to stress concentration, posing a high risk of detachment. These reliability issues with the electrode system directly cause open circuits or performance degradation in the driver circuit, thus limiting the overall lifespan and long-term operational stability of the piezoelectric actuator. Summary of the Invention

[0005] The purpose of this application is to provide a flexible electrode structure and a piezoelectric actuator to solve the technical problems of insufficient electrode toughness and weak bonding ability with piezoelectric stacks in the prior art.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: A flexible electrode structure is provided, comprising: Flexible electrode sheet; The first through groove is entirely located within the outline of the flexible electrode sheet; And / or, the second through groove at least partially intersects the contour of the flexible electrode sheet; When the flexible electrode sheet extends or contracts, the first through groove and / or the second through groove deforms to adapt to the deformation of the flexible electrode sheet.

[0007] When the piezoelectric device operates and causes the flexible electrode sheet to extend or contract, the first through groove and / or the second through groove can adapt to the deformation. The opening and closing or shape change of the groove structure can effectively release the stress in the electrode sheet, thereby improving the flexibility and durability of the electrode during cyclic deformation.

[0008] As a further improvement to the above technical solution: Optionally, the first through groove and the second through groove are alternately arranged along the length direction of the flexible electrode sheet, so that the different structural characteristics of the first through groove and the second through groove can work together along the length direction, thereby adjusting and releasing the stress in the overall structure when the flexible electrode sheet is subjected to reciprocating deformation from the piezoelectric device, and optimizing the flexibility and fatigue durability of the electrode.

[0009] Optionally, the first through slot and the second through slot are arranged parallel to each other and spaced apart, so that the stress is distributed and released more regularly and in a more controllable manner in a specific direction of the flexible electrode sheet.

[0010] When the electrode sheet undergoes directional expansion and contraction driven by the piezoelectric device, each through slot can deform in a coordinated manner, thereby systematically enhancing the deformation compliance and reliability of the electrode structure in that direction.

[0011] Optionally, the first through groove includes a transverse through groove extending along the width direction of the flexible electrode sheet, and / or a longitudinal through groove extending along the length direction of the flexible electrode sheet. The transverse through groove and the longitudinal through groove intersect each other, so that the first through groove forms a continuous grid-like stress relief structure, which can effectively adapt to the complex deformation of the flexible electrode sheet in multiple directions. The second through groove is located between the transverse through groove and / or the longitudinal through groove, further enhancing the flexibility of the local area. The two work together to improve the overall durability of the electrode sheet under dynamic working conditions.

[0012] Optionally, the first through groove is a strip groove or a square groove. Multiple first through grooves are provided along the length and / or width of the flexible electrode sheet and are symmetrically arranged with respect to the length of the flexible electrode sheet. This ensures that the stress is evenly distributed when the electrode sheet is deformed under stress, effectively avoiding local stress concentration caused by structural asymmetry, thereby improving the morphological stability and fatigue resistance of the electrode structure under cyclic loading.

[0013] Optionally, the flexible electrode sheet extends along the wavy line direction with a preset amplitude and vibration frequency, which can effectively convert the main linear strain into a flexible change in the wavy curve shape.

[0014] This structure not only increases the effective expansion and contraction margin of the electrode sheet, but also further optimizes the stress distribution through its wavy profile, significantly enhancing the electrode's ability to adapt to repeated deformations in dynamic working environments.

[0015] Optionally, it also includes a partition hole, which is centrally located relative to the width of the flexible electrode sheet and is located between each of the first through slots or the second through slots. The partition hole can effectively block or reduce the transmission and accumulation of stress in the slot area, thereby working in synergy with the first through slot and the second through slot to further refine and optimize the stress distribution of the electrode sheet under complex deformation, and enhance the overall flexibility and reliability of the structure.

[0016] The advantages of the flexible electrode structure provided in this application are as follows: The flexible electrode structure provided in this application includes a flexible electrode sheet, on which at least one of a first through groove and a second through groove is provided, that is, the structure may include a first through groove, or a second through groove, or both.

[0017] The first through-slot is entirely within the contour of the flexible electrode sheet, and its entirety does not extend beyond the boundary of the electrode sheet. The second through-slot is configured such that at least a portion intersects the contour of the flexible electrode sheet, i.e., its structure extends to the edge of the electrode sheet or forms an opening. When the piezoelectric device operates and causes the flexible electrode sheet to extend or contract, the first and / or second through-slots can adaptively deform accordingly. Through the opening and closing or morphological changes of the slot structure, the stress in the electrode sheet is effectively released, thereby improving the flexibility and durability of the electrode during cyclic deformation.

[0018] This application also provides a piezoelectric actuation device, including the above-described flexible electrode structure.

[0019] When the piezoelectric drive stack undergoes reciprocating deformation under operating voltage, the flexible electrode structure integrated on it can effectively adapt to deformation and release stress through features such as the first through slot and the second through slot, thereby significantly improving the mechanical reliability and service life of the entire piezoelectric drive device. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A cross-sectional schematic diagram of the first flexible electrode structure provided in this application; Figure 2 A cross-sectional schematic diagram of the second flexible electrode structure provided in this application; Figure 3 A cross-sectional schematic diagram of the third flexible electrode structure provided in this application; Figure 4 A cross-sectional schematic diagram of the fourth flexible electrode structure provided in this application; Figure 5 This is a schematic diagram of the main structure of the piezoelectric actuator provided in this application; Figure 6 This is a cross-sectional structural diagram of the piezoelectric actuator provided in this application.

[0022] The following are the labeling elements in the figure: 1. Flexible electrode sheet; 2. First through slot; 3. Second through slot; 4. Separator holes; 5. Piezoelectric drive stack. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0024] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of the present invention.

[0029] In the following description, suffixes such as "module," "part," "component," or "unit" are used only for the purpose of illustrative purposes and have no specific meaning in themselves. Therefore, they can be used interchangeably.

[0030] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0031] like Figures 1 to 4 As shown, this application provides a flexible electrode structure for piezoelectric devices, which mainly includes a flexible electrode sheet 1. The flexible electrode sheet 1 is configured to be attached to the surface of the piezoelectric device and used as its external electrode. At least one of a first through groove 2 and a second through groove 3 is provided on the flexible electrode sheet 1, that is, the structure may include the first through groove 2, or the second through groove 3, or both.

[0032] The first through groove 2 is completely within the contour of the flexible electrode sheet 1, and its entirety does not extend beyond the boundary of the electrode sheet. The second through groove 3 is configured such that at least a portion intersects the contour of the flexible electrode sheet 1, i.e., its structure extends to the edge of the electrode sheet or forms an opening. When the piezoelectric device operates and causes the flexible electrode sheet 1 to extend or contract, the first through groove 2 and / or the second through groove 3 can adapt to the deformation, effectively releasing the stress in the electrode sheet through the opening and closing or shape change of the groove structure, thereby improving the flexibility and durability of the electrode during cyclic deformation.

[0033] like Figures 1 to 4 As shown in a specific embodiment of this application, the first through-slot 2 and the second through-slot 3 are arranged along the length direction of the flexible electrode sheet 1, specifically in an alternating sequence. This alternating arrangement allows the different structural characteristics of the first through-slot 2 and the second through-slot 3 to combine and function along the length direction, thereby more uniformly and effectively adjusting and releasing the stress within the overall structure of the flexible electrode sheet 1 when subjected to reciprocating deformation from the piezoelectric device, thus optimizing the flexibility and fatigue durability of the electrode.

[0034] like Figures 1 to 4 As shown, in one specific embodiment of this application, the first through-slot 2 and the second through-slot 3 are configured to be parallel to each other and are spaced apart. This parallel spacing arrangement enables the stress to be distributed and released more regularly and controllably in a specific direction of the flexible electrode sheet 1. When the electrode sheet undergoes directional expansion and contraction due to the drive of the piezoelectric device, each through-slot can generate deformation in a coordinated manner, thereby systematically enhancing the deformation compliance and reliability of the electrode structure in this direction.

[0035] like Figure 2 As shown, in a specific embodiment of this application, the first through-slot 2 specifically includes a transverse through-slot portion and a longitudinal through-slot portion. The transverse through-slot portion extends along the width direction of the flexible electrode sheet 1, while the longitudinal through-slot portion extends along its length direction, and the transverse and longitudinal through-slot portions are connected and arranged in a mutually intersecting manner. A second through-slot 3 is disposed between the areas defined by the transverse and longitudinal through-slot portions. This arrangement allows the first through-slot 2 to form a continuous grid-like stress-relieving structure, effectively adapting to the complex deformation of the flexible electrode sheet 1 in multiple directions; while the second through-slot 3 disposed therebetween further enhances the flexibility of local areas. The two work together to improve the overall durability of the electrode sheet under dynamic working conditions.

[0036] like Figure 3 and Figure 4As shown, in one specific embodiment of this application, the first through-slot 2 is constructed as a regular geometric shape such as a circular slot, a strip slot, or a square slot. Multiple first through-slots 2 are provided along at least one of the length and width directions of the flexible electrode sheet 1, and these through-slots are arranged in an array or regularly distributed on the sheet. Furthermore, the arrangement of the multiple first through-slots 2 is symmetrical about the centerline of the length direction of the flexible electrode sheet 1. This symmetrical arrangement ensures that the stress is evenly distributed when the electrode sheet is deformed under stress, effectively avoiding local stress concentration caused by structural asymmetry, thereby improving the morphological stability and fatigue resistance of the electrode structure under cyclic loading.

[0037] like Figure 3 As shown, in one specific embodiment of this application, the overall shape of the flexible electrode sheet 1 is configured to extend along a wavy line trajectory with a specific amplitude and vibration frequency. This wavy structure gives the electrode sheet a periodic bending characteristic on a macroscopic level, thereby effectively converting the main linear strain into a flexible change in the wavy curve shape when the piezoelectric device drives it to produce expansion and contraction deformation. This structure not only increases the effective expansion and contraction margin of the electrode sheet, but also further optimizes the stress distribution through its wavy profile, significantly enhancing the electrode's ability to adapt to repeated deformation in dynamic working environments.

[0038] like Figures 1 to 4 As shown, in one specific embodiment of this application, the flexible electrode structure is further provided with a partition hole 4. The partition hole 4 is positioned centrally on the flexible electrode sheet 1 relative to its width direction, specifically located between adjacent first through slots 2, or between adjacent second through slots 3, or in the region between the first through slot 2 and the second through slot 3. The introduction of the partition hole 4 forms an additional stress relief node on the electrode sheet, effectively blocking or reducing the transmission and accumulation of stress in the inter-slot region. Thus, it works synergistically with the first through slot 2 and the second through slot 3 to further refine and optimize the stress distribution of the electrode sheet under complex deformation, enhancing the overall flexibility and reliability of the structure.

[0039] like Figure 5 and Figure 6 As shown, this application also provides a piezoelectric actuator, including a piezoelectric drive stack 5 and a flexible electrode structure as described in any of the preceding embodiments. Specifically, the flexible electrode structure is a flexible electrode sheet 1, which is disposed and connected to the outer surface of the piezoelectric drive stack as an external electrode. When the piezoelectric drive stack undergoes reciprocating deformation under operating voltage, the flexible electrode structure integrated thereon can effectively adapt to deformation and release stress through features such as the first through-slot 2 and the second through-slot 3, thereby significantly improving the mechanical reliability and service life of the entire piezoelectric actuator.

[0040] The various flexible electrode structures provided in this application, after being assembled into piezoelectric actuators, all exhibit excellent stress adaptability and fatigue durability. Their specific working principles and effects are detailed in the following embodiments: When using Figure 1 When the flexible electrode sheet 1 of the first form is shown, it is attached to the outer surface of the piezoelectric drive stack 5. After a working voltage is applied to the piezoelectric drive device, the piezoelectric drive stack 5 will undergo periodic micro-expansion and contraction deformation along its axial direction. At this time, the flexible electrode sheet 1, as the outer electrode, needs to follow this deformation synchronously. The first through groove 2 and the second through groove 3 in its structure play a key role in this process: they will produce corresponding elastic deformation of opening (when the stack is extended) or closing (when the stack is shortened). This local and controllable deformation effectively absorbs and releases the interfacial stress caused by the deformation mismatch between the piezoelectric material and the electrode material, thereby significantly reducing the failure risk of fatigue fracture or detachment at the electrode sheet and the solder joint.

[0041] exist Figure 2 In the second embodiment shown, the structure of the flexible electrode sheet 1 is further optimized. Its first through-slot 2 is specifically designed to include intersecting transverse and longitudinal through-slots, forming a grid-like stress-relieving unit. When the piezoelectric drive stack 5 undergoes large-amplitude expansion and contraction, this grid structure provides a wider range and more directional degrees of deformation freedom. The junction of the transverse and longitudinal slots can generate a more significant opening and closing displacement than a simple strip slot, thus more effectively adapting to more intense driving strains. This ensures that the stress level at the interface remains low under large deformation conditions, improving the reliability of the device under harsh operating conditions.

[0042] Figure 3 The third embodiment introduced is a flexible electrode sheet 1 with a wavy, linear body. This macroscopic wavy structure itself endows the electrode sheet with inherent flexibility, giving it the ability to prepare for axial expansion and contraction in its initial state. When the piezoelectric drive stack 5 is activated, the deformation of the electrode sheet is accomplished by two parts working together: first, the overall expansion or bending of the wavy body provides primary, large-scale stress buffering; second, the local opening and closing of the first through-slot 2 and the second through-slot 3 distributed on the body provides secondary, fine stress adjustment. This dual deformation mechanism combining macroscopic and microscopic aspects ensures more complete and smooth stress release.

[0043] Figure 4The fourth embodiment shown illustrates another main body form, namely a continuously S-shaped flexible electrode sheet 1. The continuous S-shaped curve structure also provides excellent ductility and resilience. During operation, the radius of curvature of the S-shaped curve dynamically changes with the expansion and contraction of the piezoelectric drive stack 5. This smooth, distributed bending deformation itself efficiently dissipates axial strain. Simultaneously, the first through-slot 2 and the second through-slot 3 distributed on the S-shaped body further adapt to and refine this deformation. Especially in areas with large bending curvature, the deformation of the through-slots plays a crucial stress relaxation role, ensuring the consistency and reliability of electrode adhesion across the entire stack surface.

[0044] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A flexible electrode structure, characterized in that, include: Flexible electrode sheet (1); The first through groove (2) is entirely located within the outline of the flexible electrode sheet (1); And / or, the second through groove (3) intersects at least partially with the contour of the flexible electrode sheet (1); When the flexible electrode sheet (1) extends or contracts, the first through groove (2) and / or the second through groove (3) deform to adapt to the deformation of the flexible electrode sheet (1).

2. The flexible electrode structure as described in claim 1, characterized in that, The first through groove (2) and the second through groove (3) are alternately arranged along the length direction of the flexible electrode sheet (1).

3. The flexible electrode structure as described in claim 2, characterized in that, The first through slot (2) and the second through slot (3) are parallel to each other and spaced apart.

4. The flexible electrode structure as described in claim 2, characterized in that, The first through groove (2) includes a transverse through groove portion extending along the width direction of the flexible electrode sheet (1) and / or a longitudinal through groove portion extending along the length direction of the flexible electrode sheet (1), wherein the transverse through groove portion and the longitudinal through groove portion are intersected. The second through groove (3) is provided between the transverse through groove and / or the longitudinal through groove.

5. The flexible electrode structure as described in claim 2, characterized in that, The first through groove (2) is a strip groove or a square groove. Multiple first through grooves (2) are provided along the length and / or width direction of the flexible electrode sheet (1) and are symmetrically arranged with respect to the length of the flexible electrode sheet (1).

6. The flexible electrode structure according to any one of claims 1 to 5, characterized in that, The flexible electrode sheet (1) extends along the wavy line direction of the preset amplitude and vibration frequency.

7. The flexible electrode structure according to any one of claims 1 to 5, characterized in that, It also includes a partition hole (4), which is centrally located relative to the width of the flexible electrode sheet (1) and is located between each of the first through slots (2) or the second through slots (3).

8. A piezoelectric actuator, characterized in that, Includes the flexible electrode structure as described in any one of claims 1 to 7.

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