A flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode and a preparation method thereof

Abstract

The present invention discloses a flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode and a preparation method thereof. The flexible piezoelectric sensing / driving dual-purpose device comprises a flexible piezoelectric functional material layer with an intermediate electrode, a lateral lead-out electrode and a flexible insulating packaging layer; the device structure is specifically arranged from top to bottom as follows: an upper flexible insulating packaging layer, a flexible piezoelectric functional material layer, left and right lateral lead-out electrodes, and a lower flexible insulating packaging layer. The flexible piezoelectric functional material is composed of micron piezoelectric ceramic columns arranged in a longitudinal and transverse array, a flexible intermediate electrode and a polymer adhesive. The preparation method of the sensing / driving dual-purpose device mainly includes a preparation method for the piezoelectric functional material, a preparation and assembly method for the lateral lead-out electrode, and a packaging method for the dual-purpose device. The flexible piezoelectric functional material with an intermediate electrode of the present invention polarizes the piezoelectric ceramic column in a direction perpendicular to the intermediate electrode, and effectively uses the piezoelectric ceramic column d during sensing and driving. 33 The piezoelectric constant greatly enhances the sensing / driving sensitivity of piezoelectric functional materials. The overall structure of the device is compact, flexible and stable. It can be well coupled with the curved surface structure as a stress / strain sensor, and can also input excitation signals for active vibration suppression drive.

Description

Technical Field

[0001] The invention relates to a flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode and a preparation method thereof. The piezoelectric sensing / driving dual-purpose device is used for plate-like structure damage monitoring and plate-like structure vibration suppression. Background Art

[0002] Piezoelectric materials are new intelligent materials developed in recent years. They have been widely used in optics, electronics, aerospace, mechanical manufacturing, bioengineering and robotics. Traditional piezoelectric ceramic sensors are generally large in size, sensitive to electrical noise, and have low flexibility and are not easy to attach to curved structures. Flexible piezoelectric ceramic / polymer composites inherit the advantages of piezoelectric ceramics such as high piezoelectricity, low ferroelectricity or pyroelectricity and high Curie point. At the same time, due to the addition of flexible polymer phase, the density, acoustic impedance and dielectric constant of flexible piezoelectric ceramic / polymer composites are reduced, and they have a certain degree of flexibility. Flexible piezoelectric ceramic / polymer composites can be used as both drivers and sensors due to their piezoelectric effect, and they have high sensitivity, fast response speed, and are suitable for high-frequency excitation. Therefore, they are increasingly used in structural health monitoring.

[0003] Among the existing flexible piezoelectric ceramic / polymer composite materials, the MacroFiber Composite (MFC) developed by NASA and the Active Fiber Composite (AFC) developed by MIT are typical representatives. They are mainly piezoelectric ceramic fiber / epoxy resin two-phase composite materials. The material has a certain flexibility only in the direction of epoxy resin bonding arrangement. The piezoelectric effect is low. 31 The conversion of electrical energy into mechanical energy is realized, and the use of interdigital electrodes results in uneven electric field distribution (there is no electric field in the piezoelectric material under the interdigital electrodes), resulting in low sensing and driving efficiency, making it difficult to meet the requirements of health monitoring of large flexible structures and large strain active vibration suppression.

[0004] Therefore, this patent describes a flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode and its preparation method. The flexible piezoelectric functional material is provided with an intermediate flexible electrode, and the micron piezoelectric ceramic column is in direct contact with the intermediate electrode, which can effectively solve the electric field "dead zone" problem existing in the existing piezoelectric fiber composite material interdigital electrode, and greatly enhance the sensing / driving sensitivity. As a piezoelectric functional element, the flexible piezoelectric functional material has the characteristics of high flexibility, fast response, high sensitivity, and good driving performance. The piezoelectric sensing / driving dual-purpose device prepared by the flexible piezoelectric functional material has a compact overall structure, good flexibility, and stable performance. It can be well coupled with the curved surface structure as a stress / strain sensor, and can also input excitation signals for active vibration suppression or structural intelligent control drive.

[0005] When the piezoelectric sensing / driving dual-purpose device described in this patent is used as a sensor, the excitation source applies a certain regular excitation waveguide to the structure to be tested. The waveguide is received by the sensor through the structure to be tested. The flexible piezoelectric functional material in the sensor converts the detected waveguide signal into an electrical signal and transmits it to the signal processing system to achieve structural damage detection. The detectable signal frequency range can be from several Hz to tens of kHz. When the piezoelectric sensing / driving dual-purpose device is used as a driver, the driver is attached or embedded in the object to be tested. When the controlled object vibrates abnormally, an excitation voltage is applied to the driver. The driver converts electrical energy into mechanical energy according to the inverse piezoelectric effect of the piezoelectric material, generates mechanical deformation or mechanical pressure applied to the structure to be tested, and achieves the purpose of vibration suppression. The flexible piezoelectric functional material with an intermediate electrode and its sensing / driving dual-purpose device overcomes the brittleness of piezoelectric ceramics and the temperature limitation of PVDF piezoelectric film, and solves the "dead zone" problem of the traditional MFC electric field, and has a strong application demand.

[0006] The invention patent with publication number CN105405963B discloses a gradient flexible piezoelectric functional material and a preparation method thereof. The flexible piezoelectric functional material prepared by this preparation method cannot solve the problem of the "dead zone" of the electric field, and the driving performance is poor. The invention patent with publication number CN107565013A discloses a longitudinal gradient short fiber flexible piezoelectric functional material and a preparation method thereof. This preparation method has complicated steps, is difficult to prepare in practice, has high requirements on equipment, cannot effectively carry out process control, has too low efficiency, and is not easy to mass-produce automatically. Summary of the invention

[0007] The main purpose of the present invention is to provide a flexible piezoelectric sensing / driving dual-purpose device that can drive and sense and a preparation method thereof. When used as a sensor, it can realize the impact load positioning, impact energy and damage state detection, and when used as a driver, it can be used for active vibration suppression of flexible structures. The sensor / driver has the characteristics of large bidirectional flexibility, fast response, high sensitivity, good driving performance, etc., and has good application value.

[0008] In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions: A flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode and a preparation method thereof are characterized in that the flexible piezoelectric functional material is composed of micron piezoelectric ceramic columns arranged along a longitudinal and transverse array, a flexible intermediate electrode and a polymer adhesive. The flexible piezoelectric sensing / driving dual-purpose device includes a flexible piezoelectric functional material layer, a lateral lead-out electrode and a flexible insulating packaging layer; the preparation method of the sensing / driving dual-purpose device includes a preparation method for the flexible piezoelectric functional material, a preparation and assembly method for the lateral lead-out electrode, and a device packaging method.

[0009] Further: the flexible piezoelectric sensing / driving dual-purpose device includes a piezoelectric functional material layer, a lateral lead-out electrode and a flexible insulating packaging layer, and the specific layout of the device structure is: with the flexible piezoelectric functional material as the center, lateral lead-out electrodes are installed on the left and right sides, and the upper and lower sides are covered with flexible insulating packaging layers respectively.

[0010] Further: the flexible piezoelectric functional material is formed by micron piezoelectric ceramic columns arranged in arrays in the horizontal and vertical directions, and different polymers are poured into the horizontal grooves and the vertical grooves to bond and form a flexible conductive glue. The specific structure is represented as follows: micron piezoelectric ceramic columns of the same size are uniformly arranged in the horizontal and vertical directions, polymer adhesives are poured into the vertical gaps, and flexible conductive glue is poured into the horizontal gaps to form a flexible piezoelectric functional material layer.

[0011] Furthermore: the intermediate electrode is a flexible conductive glue that runs transversely through and is arranged in parallel in the flexible piezoelectric functional material. The intermediate electrode is in direct contact with the piezoelectric ceramic column, and each two adjacent intermediate electrodes form a uniform parallel electric field when working or polarizing.

[0012] Further: the lateral extraction electrode is a "nail rake-shaped" copper electrode, and the copper electrode is provided with regularly arranged "electrode nails", and the spacing of the "electrode nails" is twice the spacing of the middle electrodes. The "nail rake-shaped" copper electrode is installed on the left and right sides of the flexible piezoelectric functional material, and the "electrode nails" are staggered from the side into the middle electrode of the flexible piezoelectric functional material to ensure that the lateral extraction electrode is connected to the corresponding middle electrode, so that the polarization directions of the piezoelectric ceramic columns between the two adjacent middle electrodes are opposite during polarization.

[0013] Further: the flexible piezoelectric functional material, wherein the micron piezoelectric ceramic column is a PZT-based piezoelectric ceramic, wherein the polymer binder is an epoxy resin with good flexibility, wherein the flexible conductive glue is a conductive silver glue with strong conductivity, good adhesion and flexibility. The lateral lead-out electrode is made of copper with good conductivity and flexibility.

[0014] Further: the flexible insulating packaging layer material is a mica film or a polyimide film having insulation, weather resistance and certain high temperature resistance, and the film thickness can be selected from 0.01mm to 1.00mm according to the size of the sensor.

[0015] A method for preparing a flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode comprises the following steps:

[0016] S1. One-time cutting of piezoelectric functional materials: Fix the prefabricated piezoelectric ceramic block in a fixture, set the cutting parameters, and use a ceramic dicing machine to perform a transverse groove on the ceramic block. The groove depth is less than the height of the green body, and the grooves are arranged equidistantly.

[0017] S2. Filling of primary polymer binder of piezoelectric functional material: According to the design requirements of piezoelectric sensing / driving dual-purpose device, a certain proportion of epoxy resin is prepared and placed in a fully automatic degassing mixer to fully mix and eliminate bubbles. Fill it into the cut groove of the piezoelectric ceramic body, and place it in a vacuum drying oven, vacuum cure it at 50°C, grind off the excess polymer on the surface, and obtain a piezoelectric ceramic sheet / polymer block.

[0018] S3. Secondary cutting of piezoelectric functional materials: Fix the dried piezoelectric ceramic sheet / polymer block in a fixture, set the cutting parameters, and use a ceramic dicing machine to perform a second uniform grooving of the body perpendicular to the first grooving direction. The groove depth is less than or equal to the first groove depth, and the grooves are arranged equidistantly.

[0019] S4. Filling of secondary conductive adhesive with piezoelectric functional material: Use conductive adhesive with good flexibility to fill the secondary grooves, and then place them in a vacuum drying oven and cure them in a vacuum environment at 50°C to obtain a piezoelectric ceramic column / polymer / conductive adhesive composite material blank with an intermediate electrode.

[0020] S5. Preparation of piezoelectric functional materials: Fix the piezoelectric ceramic column / polymer / conductive adhesive composite material block with an intermediate electrode on a fixture, use laser pulse cutting equipment to cut the body perpendicular to the groove depth direction, grind and thin it, and obtain a sheet-like flexible piezoelectric functional material product containing an intermediate electrode layer.

[0021] S6. Preparation of lateral lead-out electrodes for flexible piezoelectric sensing / actuating devices: Use chemical methods to roughen the surfaces of both sides of the metal copper film, use laser cutting to cut into "rake-shaped" copper electrodes, and then stamp and bend the copper film to form "electrode nails."

[0022] S7. Installation of lateral lead-out electrodes of flexible piezoelectric sensing / driving dual-purpose devices: Apply epoxy resin glue on the inner side of the metal copper film, and insert the "electrode pins" of the lateral lead-out electrodes into the middle electrodes of the flexible piezoelectric functional material from the side in an alternating manner with each other through a conductive glue layer to ensure that the lateral lead-out electrodes are conductively connected to the corresponding middle electrodes.

[0023] S8: Polarization of flexible piezoelectric sensing / driving dual-purpose device: Connect the wiring terminals of the left and right lateral lead electrodes to the positive and negative terminals of the DC polarization system respectively, place the entire flexible piezoelectric functional material product in a silicone oil or vacuum insulation environment, set the polarization parameters (such as polarization electric field, polarization temperature and polarization time, etc.), and polarize to obtain a flexible piezoelectric functional material with piezoelectric effect.

[0024] S9: Flexible piezoelectric sensing / driving dual-purpose device packaging: Through the adhesive dispensing equipment, precise dispensing and uniform scraping, the polyimide film or mica film is covered on the upper and lower surfaces of the flexible piezoelectric functional material with the intermediate electrode, and then cured and packaged, and finally a flexible piezoelectric functional material sensing / driving dual-purpose device with an intermediate electrode is obtained.

[0025] A method for using a flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode, the method comprising:

[0026] (1) When the piezoelectric sensor / actuator dual-purpose device is used as a sensor, it is attached to the surface of the structure to be detected, and the lateral electrode terminal is connected to the signal acquisition device. During detection, an exciter is placed on the surface of the structure to be detected, and the exciter generates ultrasonic guided waves. The guided waves pass through the object to be detected and are received by the sensor. The sensor converts the mechanical energy of the guided waves into electrical energy and transmits it to the signal processing system, thereby realizing damage monitoring of the object to be detected.

[0027] (2) When the piezoelectric sensor / actuator dual-purpose device is used as a driver, it is attached to the surface of the structure to be controlled, and the lateral lead-out electrode terminal is connected to the signal generating device. When the signal generating device sends out an alternating electrical signal, the driver converts the electrical energy into mechanical energy, generates a corresponding action on the structure to be controlled, and realizes vibration suppression.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The piezoelectric sensing / actuating dual-purpose device prepared by the present invention has significant advantages such as high flexibility, good piezoelectricity, and low acoustic impedance. It can overcome the shortcomings of piezoelectric ceramics such as brittleness, temperature limitation of PVDF piezoelectric film, and uneven electric field distribution of MFC, as well as high price and low overall efficiency.

[0030] (2) Common piezoelectric ceramic materials are brittle and hard, and traditional piezoelectric fiber composite materials (MFC) can only be bent in one direction and are usually only used for damage monitoring of flat plate structures. The piezoelectric functional material with a flexible intermediate electrode of the present invention can achieve bidirectional bending and can be applied to large curvature curved surface structures.

[0031] (3) The piezoelectric sensing / driving dual-purpose device prepared by the present invention is a mechanical / electrical energy transducer based on the piezoelectric effect. Its structure and function can be used as a sensor in active / passive monitoring and as an actuator in active monitoring.

[0032] (4) The piezoelectric sensing / driving dual-purpose device prepared by the present invention has a polarization direction consistent with the driving electric field direction, which effectively utilizes the piezoelectric effect. 33 Constant, which improves the sensitivity of the sensor and the driver.

[0033] (5) In the piezoelectric sensing / driving dual-purpose device prepared by the present invention, the polarization directions of the piezoelectric ceramic columns between the two adjacent middle electrodes are opposite. When used as a piezoelectric driver, each piezoelectric ceramic column in the piezoelectric functional material has consistent elasticity. Compared with other drivers (such as MFC), it can achieve a larger elastic strain under the same driving voltage, thereby improving its driving efficiency.

[0034] (6) The piezoelectric driver in the present invention can provide mechanical force through flexible piezoelectric materials to stimulate or effectively suppress vibration. The technology is relatively mature, with high control accuracy and can be applied to different structures. It has the characteristics of fast response, high sensitivity, high driving efficiency, etc., and has good application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a three-dimensional schematic diagram of the flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode of the present invention.

[0036] Figure 2 It is a three-dimensional schematic diagram of the flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode of the present invention without the packaging layer.

[0037] Figure 3 It is a schematic diagram of the structural decomposition of the flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode of the present invention.

[0038] Figure 4 It is a schematic diagram of the structure of the flexible piezoelectric functional material of the present invention.

[0039] Figure 5 It is a schematic diagram of the lateral extraction electrode structure of the present invention.

[0040] Figure 6 It is a schematic diagram of the preparation process of the lateral extraction electrode of the present invention.

[0041] Figure 7 It is a schematic diagram of the preparation process of the piezoelectric sensing / driving dual-purpose device of the present invention.

[0042] Figure 8 It is a flowchart of the preparation process of the invented piezoelectric sensing / driving dual-purpose device.

[0043] in:

[0044] 1—upper insulating packaging layer, 2—flexible piezoelectric functional material, 21—micrometer piezoelectric ceramic column, 22—polymer adhesive, 23—flexible conductive adhesive, 3—lateral lead-out electrode, 31—electrode pin, 32—connection terminal, 4—lower insulating packaging layer. DETAILED DESCRIPTION

[0045] The present invention is further described in detail below with reference to the accompanying drawings and actual cases.

[0046] like Figure 1 As shown, the flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode provided by the present invention mainly includes: an upper packaging layer 1, a flexible piezoelectric functional material 2, a lateral lead-out electrode 3, and a lower packaging layer 4.

[0047] like Figure 2 As shown, the device structure of the flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode provided by the present invention.

[0048] like Figure 3 As shown, the device structure of the flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode provided by the present invention.

[0049] like Figure 4 As shown, the schematic diagram of the structure of flexible piezoelectric functional material.

[0050] like Figure 5 As shown, the lateral lead-out electrode structure mainly includes: "electrode pin" and terminal.

[0051] like Figure 6 It is shown that the surfaces of both sides of the metal copper film are roughened, and then the metal copper film is cut and punched and bent to form "electrode nails".

[0052] like Figure 7 Shown is the flow chart for the preparation of flexible piezoelectric functional materials.

[0053] like Figure 8 Shown is a flowchart of the preparation process of a piezoelectric sensing / actuating dual-purpose device.

[0054] like Figures 1 to 8 The present invention provides a method for preparing a flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode, and the specific steps are as follows:

[0055] S1. One-time cutting of piezoelectric functional materials: Fix the prefabricated piezoelectric ceramic block in a fixture, set the cutting parameters, and use a ceramic dicing machine to perform a transverse groove on the ceramic block. The groove depth is less than the height of the green body, and the grooves are arranged equidistantly.

[0056] S2. Filling of primary polymer binder of piezoelectric functional material: According to the design requirements of piezoelectric sensing / driving dual-purpose device, a certain proportion of 22 epoxy resin is prepared and placed in a fully automatic degassing mixer to fully mix and eliminate bubbles. Fill it into the groove of the piezoelectric ceramic body, and place it in a vacuum drying oven, vacuum cure it at 50°C, grind off the excess polymer on the surface, and obtain a piezoelectric ceramic sheet / polymer block.

[0057] S3. Secondary cutting of piezoelectric functional materials: Fix the dried piezoelectric ceramic sheet / polymer block in a fixture, set the cutting parameters, and use a ceramic dicing machine to perform a second uniform grooving of the body perpendicular to the first grooving direction. The groove depth is less than or equal to the first groove depth, and the grooves are arranged equidistantly.

[0058] S4. Filling of secondary conductive adhesive with piezoelectric functional material: Use 23 conductive adhesive with good flexibility to fill the secondary grooves, and then place them in a vacuum drying oven and cure them in a vacuum environment at 50°C to obtain a piezoelectric ceramic column / polymer / conductive adhesive composite material blank with an intermediate electrode.

[0059] S5. Preparation of piezoelectric functional materials: Fix the piezoelectric ceramic column / polymer / conductive adhesive composite material block with an intermediate electrode on a fixture, use laser pulse cutting equipment to cut the body perpendicular to the groove depth direction to prepare slices, grind and thin it, and obtain a sheet-like 2 flexible piezoelectric functional material product containing an intermediate electrode layer.

[0060] S6. Preparation of lateral lead-out electrodes for flexible piezoelectric sensing / actuating devices: Use chemical methods to roughen the surfaces of both sides of the metal copper film, use laser cutting to cut into "rake-shaped" copper electrodes, and then stamp and bend the copper film to fold out 31 "electrode nails".

[0061] S7. Installation of lateral lead-out electrodes of flexible piezoelectric sensing / driving dual-purpose devices: Apply epoxy resin glue on the inner side of the metal copper film, and insert the 31 "electrode pins" of the lateral lead-out electrodes into the middle electrode of the flexible piezoelectric functional material from the side in an alternating manner with every other conductive glue layer to ensure that the lateral lead-out electrodes are conductively connected to the corresponding middle electrodes.

[0062] S8: Polarization of flexible piezoelectric sensing / driving dual-purpose device: Connect the 32 terminals of the left and right lateral lead electrodes to the positive and negative terminals of the DC polarization system respectively, put the entire flexible piezoelectric functional material product into silicone oil or vacuum insulation environment, set the polarization parameters (such as polarization electric field, polarization temperature and polarization time, etc.), and polarize to obtain a flexible piezoelectric functional material with piezoelectric effect.

[0063] S9: Flexible piezoelectric sensing / driving dual-purpose device packaging: Through the adhesive dispensing equipment, precise dispensing and uniform scraping, the polyimide film or mica film is covered on the upper and lower surfaces of the flexible piezoelectric functional material with the intermediate electrode, and then cured and packaged, and finally a flexible piezoelectric functional material sensing / driving dual-purpose device with an intermediate electrode is obtained.

[0064] The method for using the flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode provided by the present invention is as follows: the method comprises:

[0065] (1) When the piezoelectric sensor / actuator dual-purpose device is used as a sensor, it is attached to the surface of the structure to be detected, and the lateral electrode terminal is connected to the signal acquisition device. During detection, an exciter is placed on the surface of the structure to be detected, and the exciter generates ultrasonic guided waves. The guided waves pass through the object to be detected and are received by the sensor. The sensor converts the mechanical energy of the guided waves into electrical energy and transmits it to the signal processing system, thereby realizing damage monitoring of the object to be detected.

[0066] (2) When the piezoelectric sensor / actuator dual-purpose device is used as a driver, it is attached to the surface of the structure to be controlled, and the lateral lead-out electrode terminal is connected to the signal generating device. When the signal generating device sends out an alternating electrical signal, the driver converts the electrical energy into mechanical energy, generates a corresponding action on the structure to be controlled, and realizes vibration suppression.

[0067] It should be noted that, in this article, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method of the present invention and its core idea. The above is only a preferred implementation method of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements, modifications or changes can be made, and the above technical features can be combined in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the invention to other occasions without improvement, should be regarded as the protection scope of the present invention.

Claims

1. A flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode, characterized in that: The flexible piezoelectric sensing / driving dual-purpose device comprises: a flexible piezoelectric functional material layer, a lateral lead-out electrode and a flexible insulating packaging layer; the flexible piezoelectric functional material layer comprises: micron piezoelectric ceramic columns arranged along a longitudinal and transverse array, a flexible intermediate electrode and a polymer adhesive; The flexible piezoelectric functional material layer is formed by micron piezoelectric ceramic columns arranged in arrays in the transverse and longitudinal directions, and different polymer adhesives and flexible intermediate electrodes are poured into the transverse grooves and the longitudinal grooves; the specific structure is represented as follows: micron piezoelectric ceramic columns with the same size are uniformly arranged in the transverse and longitudinal directions, polymer adhesives are poured into the longitudinal gaps, and flexible intermediate electrodes are poured into the transverse gaps to form a flexible piezoelectric functional material layer; The flexible intermediate electrode and the flexible piezoelectric functional material layer are transversely connected and arranged in parallel; The lateral lead-out electrode is a rake-shaped copper electrode, and the copper electrode is provided with regularly arranged electrode nails. The rake-shaped copper electrode is installed on the left and right sides of the flexible piezoelectric functional material layer, and the electrode nails are inserted into the flexible intermediate electrode in an alternating manner from the side to ensure that the lateral lead-out electrode is conductive with the corresponding intermediate electrode, so that the polarization directions of the micron piezoelectric ceramic columns between the two adjacent flexible intermediate electrodes are opposite during polarization.

2. A flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode according to claim 1, characterized in that: The flexible piezoelectric sensing / driving dual-purpose device includes a flexible piezoelectric functional material layer, a lateral lead-out electrode and a flexible insulating packaging layer. The specific layout of the device structure is: with the flexible piezoelectric functional material layer as the center, lateral lead-out electrodes are installed on the left and right sides, and the upper and lower sides are covered with flexible insulating packaging layers respectively.

3. A flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode according to claim 1, characterized in that: The flexible middle electrode is a flexible conductive glue, and the flexible conductive glue is in direct contact with the micron piezoelectric ceramic column. Each two adjacent flexible middle electrodes form a uniform parallel electric field when working or polarizing.

4. A flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode according to claim 1, characterized in that: The spacing between the electrode nails is twice the spacing between the flexible middle electrodes.

5. The flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode according to claim 1, characterized in that: The flexible piezoelectric functional material layer, wherein the micron piezoelectric ceramic column is a PZT-based piezoelectric ceramic, wherein the polymer binder is an epoxy resin with good flexibility, wherein the flexible conductive glue is a conductive silver glue with strong conductivity, good adhesion and flexibility; the lateral lead-out electrode is made of copper with good conductivity and flexibility.

6. A flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode according to claim 2, characterized in that: The material of the flexible insulating packaging layer is a mica film or a polyimide film having insulation, weather resistance and certain high temperature resistance. The thickness of the film is selected from 0.01mm to 1.00mm according to the size of the sensor. mm thickness.

7. A method for preparing a flexible piezoelectric sensing / driving dual-purpose device with an intermediate electrode according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: S1. Primary cutting of piezoelectric functional materials: fix the prefabricated piezoelectric ceramic block in a fixture, set cutting parameters, and use a ceramic dicing machine to perform a transverse groove on the ceramic block. The groove depth is less than the height of the green body, and the grooves are arranged equidistantly. S2. Filling of primary polymer binder of piezoelectric functional material: according to the design requirements of piezoelectric sensing / driving dual-purpose device, prepare a certain proportion of epoxy resin, place it in a fully automatic degassing mixer to fully mix and eliminate bubbles, fill it into the cut groove of the piezoelectric ceramic body, and place it in a vacuum drying oven, vacuum cure it at 50°C, grind off the excess polymer on the surface, and obtain a piezoelectric ceramic sheet / polymer block; S3, secondary cutting processing of piezoelectric functional materials: fix the dried piezoelectric ceramic sheet / polymer block in a fixture, set the cutting parameters, use a ceramic dicing machine to perform a secondary uniform grooving on the body perpendicular to the primary grooving direction, the groove depth is less than or equal to the first groove depth, and the grooves are arranged equidistantly; S4. Filling the secondary conductive adhesive of the piezoelectric functional material: Use a conductive adhesive with good flexibility to fill the secondary cut grooves, and then place it in a vacuum drying oven and solidify it under a vacuum environment of 50°C to obtain a piezoelectric ceramic column / polymer / conductive adhesive composite material blank with an intermediate electrode; S5. Preparation of piezoelectric functional materials: Fix the piezoelectric ceramic column / polymer / conductive adhesive composite material block with the intermediate electrode on the fixture, use laser pulse cutting equipment to cut the blank perpendicular to the groove depth direction, grind and thin it, and obtain a sheet-shaped flexible piezoelectric functional material product containing an intermediate electrode layer; S6. Preparation of lateral lead-out electrodes for flexible piezoelectric sensing / actuating devices: Use chemical methods to roughen the surfaces of both sides of the metal copper film, use laser cutting to form "rake-shaped" copper electrodes, and then perform stamping and bending on the copper film to form "electrode nails"; S7. Installation of lateral lead-out electrodes of flexible piezoelectric sensing / driving dual-purpose devices: Apply epoxy resin glue on the inner side of the metal copper film, and insert the "electrode pins" of the lateral lead-out electrodes into the middle electrodes of the flexible piezoelectric functional material from the side in an alternating manner with each other in a conductive glue layer to ensure that the lateral lead-out electrodes are conductive with the corresponding middle electrodes; S8. Polarization of flexible piezoelectric sensing / driving dual-purpose device: Connect the wiring terminals of the left and right lateral lead electrodes to the positive and negative terminals of the DC polarization system respectively, put the entire flexible piezoelectric functional material product into a silicone oil or vacuum insulation environment, set the polarization parameters, and polarize to obtain a flexible piezoelectric functional material with piezoelectric effect; S9. Flexible piezoelectric sensing / driving dual-purpose device packaging: Through the adhesive dispensing equipment, precise dispensing and uniform scraping, the polyimide film or mica film is covered on the upper and lower surfaces of the flexible piezoelectric functional material with the intermediate electrode, and then cured and packaged, and finally a flexible piezoelectric functional material sensing / driving dual-purpose device with an intermediate electrode is obtained.

8. The method for using the flexible piezoelectric sensing / driving dual-purpose device according to any one of claims 1 to 6, characterized in that: When the flexible piezoelectric sensing / driving dual-purpose device is used as a sensor, it is attached to the surface of the structure to be detected, and the lateral lead-out electrode terminal is connected to the signal acquisition device. During detection, an exciter is placed on the surface of the structure to be detected, and the exciter generates ultrasonic guided waves. The guided waves pass through the object to be detected and are received by the sensor. The sensor converts the mechanical energy of the guided waves into electrical energy and transmits it to the signal processing system, thereby realizing damage monitoring of the object to be detected; When the flexible piezoelectric sensing / driving dual-purpose device is used as a driver, it is attached to the surface of the structure to be controlled, and the lateral electrode terminals are connected to the signal generating device. When the signal generating device sends out an alternating electric signal, the driver converts the electrical energy into mechanical energy, generates corresponding actions on the structure to be controlled, and realizes vibration suppression.

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