Piezoelectric composite film and preparation method thereof

Abstract

The present invention relates to the technical field of composite film preparation, and specifically discloses a piezoelectric composite film and a preparation method thereof. The preparation method comprises: preparing a PZT fiber with an inner diameter of 300 μm-500 μm and a length of 300 μm-1000 μm, and crystallizing the PZT fiber into a phase; compounding the crystallized PZT fiber with an organic polymer in a mass ratio of 1:1 to 1:4, and stirring the PZT fiber and the organic polymer to form a slurry; flattening the surface of the slurry to obtain a piezoelectric body; longitudinally stretching the piezoelectric body to obtain a piezoelectric block with consistent PZT fiber orientation; cutting the surface of the piezoelectric block; and polarizing the cut piezoelectric block to obtain a piezoelectric composite film. The preparation method can fully polarize the PZT fiber, improve the piezoelectric performance of the composite film, and the uniform dispersion of the PZT fiber in the organic polymer can also make the piezoelectric composite film both windable.

Description

Technical Field

[0001] The present invention relates to the technical field of composite film preparation, and in particular to a piezoelectric composite film and a preparation method thereof. Background Art

[0002] With the rapid development of integrated circuit technology and the continuous improvement in the energy harvesting efficiency of piezoelectric materials, it has become possible to self-power low-energy devices such as wireless sensors by harvesting energy from the environment. Due to the increasing requirements for piezoelectric materials in current tactile feedback applications (such as VR, artificial skin, and flexible sensors), these materials are required to have both a high piezoelectric constant (D33) and good bendability.

[0003] However, the performance of existing piezoelectric composite films cannot meet the material requirements for tactile feedback. Therefore, it is urgent to prepare a piezoelectric composite film with a high piezoelectric constant D33 and strong winding properties. Summary of the Invention

[0004] The invention discloses a piezoelectric composite film and a preparation method thereof, which can prepare a uniformly oriented PZT piezoelectric composite film and improve the piezoelectric performance and windability of the piezoelectric composite film.

[0005] In order to achieve the above-mentioned objectives, in a first aspect, an embodiment of the present invention discloses a method for preparing a piezoelectric composite film, comprising: preparing PZT fibers with an inner diameter of 300μm-500μm and a length of 300μm-1000μm, and crystallizing the PZT fibers; compounding the crystallized PZT fibers with an organic polymer in a mass ratio of 1:1 to 1:4, and stirring the PZT fibers and the organic polymer evenly to form a slurry; pouring the slurry into a pre-prepared forming tank, scraping the surface of the slurry flat, and then baking the slurry to prepare a piezoelectric body; longitudinally stretching the piezoelectric body to obtain a piezoelectric block with the PZT fibers having a consistent orientation; cutting the surface of the piezoelectric block so that the PZT fibers are exposed on the upper and lower surfaces of the piezoelectric block; and polarizing the cut piezoelectric block to prepare a piezoelectric composite film.

[0006] This preparation method involves preparing micron-sized PZT fibers and dispersing them in an organic polymer matrix. The PZT fibers are then stretched into uniformly oriented PZT fibers using a stretching method. The fibers are then cut and polarized to produce a piezoelectric composite film. The uniformly oriented PZT fibers in this piezoelectric composite film penetrate the organic polymer, allowing for complete polarization and improving the piezoelectric performance of the composite film. Furthermore, the uniform dispersion of the PZT fibers in the organic polymer makes the piezoelectric composite film both windable and suitable for tactile feedback applications requiring piezoelectric materials.

[0007] As an optional implementation, in an embodiment of the present invention, the PZT fiber is prepared by using at least one of an electrospinning method, an extrusion molding method, and a condensation water bath method, which can achieve automated, continuous, and efficient production of the PZT fiber.

[0008] As an optional embodiment, in an embodiment of the present invention, the preparation of PZT fibers with an inner diameter of 300μm-500μm and a length of 300μm-1000μm, and crystallizing the PZT fibers into phases, include the following steps: preparing PZT fibers with an inner diameter of 300μm-500μm and a length of 300μm-1000μm; placing the PZT fibers into a heating furnace; and heating the PZT fibers at a temperature of 1000℃-1300℃ for 3h-8h in the heating furnace to crystallize the PZT fibers into phases, thereby preventing the PZT fibers from being broken up or deformed by stirring during the mixing process with the organic mixture, and ensuring the structural integrity of the PZT fibers.

[0009] As an optional embodiment, in an embodiment of the present invention, the organic polymer is PDMS, PE, or PP. Setting the organic mixture to PDMS, PE, or PP allows for thorough mixing with the PZT fibers, resulting in excellent insulation properties and ensuring a high dielectric constant for the resulting piezoelectric composite film.

[0010] As an optional embodiment, in an embodiment of the present invention, the PZT fibers and the organic polymer are uniformly stirred by magnetic force to form a slurry. Mixing the PZT fibers and the organic polymer by magnetic stirring not only allows the PZT fibers and the organic polymer to be stirred, but also heats them during the stirring and mixing process, thereby increasing the mixing speed and shortening the mixing time.

[0011] As an optional implementation, in an embodiment of the present invention, the forming groove is formed by attaching and surrounding the glass plate with adhesive tape, which has a simple structure and is easy to implement.

[0012] As an optional implementation manner, in an embodiment of the present invention, the piezoelectric body is baked at a temperature of 50° C. to 150° C. for 1 hour to 10 hours, so that the piezoelectric body can be quickly prepared.

[0013] As an optional embodiment, in an embodiment of the present invention, the piezoelectric element is heated at a temperature of 100° C. to 150° C. during the stretching process. Stretching the piezoelectric element longitudinally under heating conditions ensures the stretching continuity of the PZT fiber and prevents breakage of the PZT fiber during the stretching process.

[0014] As an optional implementation, in an embodiment of the present invention, after cutting the piezoelectric block and before polarizing the piezoelectric block, the piezoelectric block is polished with 8000-10000 mesh sandpaper, which can quickly make the surface of the piezoelectric block smoother, ensure that the polarization material can fully contact the piezoelectric block, and thus facilitate the full polarization of the PZT fiber, thereby improving the piezoelectric coefficient of the piezoelectric composite film finally prepared.

[0015] As an optional implementation, in an embodiment of the present invention, the piezoelectric block is polarized by applying copper foil on the surface of the piezoelectric block. Copper foil can be stably and quickly attached to an organic polymer.

[0016] In the second aspect, an embodiment of the present invention further discloses a piezoelectric composite film, which is prepared by the above-mentioned method for preparing a piezoelectric composite film, and the piezoelectric composite film includes: an organic polymer body, the organic polymer body including a first surface and a second surface opposite to the first surface; at least two sections of PZT fibers, the PZT fibers are distributed in the organic polymer body, the PZT fibers are oriented in the same direction and extend along the thickness direction of the organic polymer body, and the two ends of the PZT fibers protrude from the first surface and the second surface respectively; and two electrode layers, the two electrode layers include a first electrode layer and a second electrode layer, the first electrode layer is laid on the first surface and in contact with the PZT fibers, and the second electrode layer is laid on the second surface and in contact with the PZT fibers.

[0017] The piezoelectric composite film of the present invention comprises uniformly oriented PZT fibers that penetrate the organic polymer matrix and directly contact the electrode layer, maximizing polarization of the PZT fibers within the piezoelectric composite film and improving the piezoelectric performance of the piezoelectric composite film. Furthermore, at least two segments of PZT fibers are dispersed within the organic polymer matrix, providing a wide range of motion and enabling relative movement without breakage or loss. Consequently, the piezoelectric composite film of this embodiment exhibits high coilability.

[0018] As an optional embodiment, in an embodiment of the present invention, the PZT fibers are cylindrical, with an inner diameter of 300 μm to 500 μm and a height of 300 μm to 1000 μm. Within this range, the mechanical stress differences caused by overly thin PZT fibers are avoided, while the upper limit of the PZT fibers in the composite film, which would be affected by overly thick PZT fibers, is also avoided, thereby improving the strength and stability of the piezoelectric composite film.

[0019] As an optional implementation, in an embodiment of the present invention, the electrode layer is a copper foil layer, which has a simple structure, is easily bonded to the organic polymer body, and has a stable and reliable structure.

[0020] Compared with the prior art, the piezoelectric composite film and the preparation method thereof of the present invention have at least the following beneficial effects:

[0021] The preparation method of the piezoelectric composite film of the present invention prepares micron PZT fibers by electrospinning, disperses the PZT fibers in an organic polymer matrix, uses a stretching method to stretch the PZT fibers into uniformly oriented PZT fibers, and then cuts, polishes, and polarizes to form an organic, windable piezoelectric composite film with uniformly oriented PZT fibers.

[0022] The piezoelectric composite film prepared by the preparation method has the following advantages:

[0023] (1) The piezoelectric composite film has uniformly oriented PZT fibers, and the PZT fibers penetrate the piezoelectric composite film and can directly contact the electrode material, which can maximize the polarization of the PZT fibers in the piezoelectric composite film and improve the piezoelectric performance of the piezoelectric composite film;

[0024] (2) Because the PZT fibers are evenly dispersed in the organic polymer, they have a large degree of freedom of movement and can move relative to each other without breaking or falling off. Therefore, the piezoelectric composite film has high windability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 is a flow chart of a method for preparing a piezoelectric composite film disclosed in an embodiment of the present invention;

[0027] Figure 2 is a top view of the adhesive tape disclosed in an embodiment of the present invention applied to a glass plate;

[0028] Figure 3 yes Figure 2 sectional view of

[0029] Figure 4 is a schematic diagram of a piezoelectric body stretched into a piezoelectric block according to an embodiment of the present invention;

[0030] Figure 5 Schematic diagram of the piezoelectric block disclosed in an embodiment of the present invention after cutting, polishing, and polarization to form a piezoelectric composite film;

[0031] Figure 6 Schematic diagram of the piezoelectric composite film disclosed in an embodiment of the present invention.

[0032] Icons: 10, PZT fiber; 20, organic polymer body; 21, first surface; 22, second surface; 30, electrode layer; 31, first electrode layer; 32, second electrode layer; 40, tape; 50, glass plate; 60, molding groove. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0034] In the present invention, terms such as "upper," "lower," "left," "right," "front," "back," "top," "bottom," "inner," "outer," "center," "vertical," "horizontal," "transverse," and "longitudinal" indicate positions or locations based on the positions or locations shown in the accompanying drawings. These terms are primarily intended to better describe the present invention and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific orientation, or to being constructed or operated in a specific orientation.

[0035] Furthermore, some of the above terms may be used to express other meanings besides indicating a position or location. For example, the term "on" may also be used to indicate a dependency or connection in certain circumstances. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0036] Furthermore, the terms "installed," "disposed," "provided with," "connected," and "connected" should be interpreted broadly. For example, they can refer to fixed connections, removable connections, or integral structures; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; or internal communication between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0037] In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified, "plurality" means two or more.

[0038] As mentioned in the background technology above, the windability of existing piezoelectric materials is difficult to meet the needs of VR (virtual reality), artificial skin, foldable sensors, etc. To this end, the present invention provides a method for preparing a piezoelectric composite film, which prepares micron-sized PZT fibers (lead zirconate titanate piezoelectric ceramic fibers), disperses them in an organic polymer matrix, uses a stretching method to stretch the PZT fibers into uniformly oriented PZT fibers, and then cuts and polishes them to form a windable piezoelectric composite film with uniformly oriented PZT fibers. The uniformly oriented PZT fibers in the piezoelectric composite film penetrate the organic polymer, which can fully polarize the PZT fibers and improve the piezoelectric properties of the composite film. In addition, the uniform dispersion of the PZT fibers in the organic polymer can also make the piezoelectric composite film both windable and able to meet the use requirements of tactile feedback (VR, artificial skin, foldable sensors, etc.) for piezoelectric materials.

[0039] The following is a detailed description with reference to the accompanying drawings.

[0040] Example 1

[0041] See Figures 1 to 4 As shown, Figure 1 This is a flow chart of the method for preparing the piezoelectric composite film disclosed in Example 1 of the present invention. Figure 2 This is a top view of the adhesive tape disclosed in the first embodiment of the present invention when applied to a glass plate. Figure 3 yes Figure 2 sectional view of . Figure 4 Schematic diagram of the piezoelectric body after being stretched into a piezoelectric block according to the first embodiment of the present invention. Specifically, the method for preparing the piezoelectric composite film in this embodiment includes the following steps:

[0042] 101. Prepare a PZT fiber 10 with an inner diameter of 300 μm-500 μm and a length of 300 μm-1000 μm, and crystallize the PZT fiber 10 into a phase.

[0043] Specifically, in this embodiment, the PZT fiber 10 is prepared using an electrospinning method. This electrospinning method is a special form of electrostatic atomization of polymer fluids. The substances split by the atomization are not tiny droplets, but rather tiny polymer jets. The polymer solution or melt is spray-spun in a strong electric field and can travel a considerable distance. This method can produce PZT fibers 10 with a nanometer diameter. In other embodiments of the present invention, the PZT fiber 10 can also be prepared by an extrusion molding method. The extrusion molding method can extrude products of various shapes, has high production efficiency, and can automatically and continuously produce PZT fibers 10. In another embodiment of the present invention, the PZT fiber 10 can also be prepared by a condensation water bath method.

[0044] Furthermore, the specific inner diameter and length of the PZT fiber 10 in the embodiment may be as shown in Table 1, for example.

[0045] Table 1:

[0046] Inner diameter of PZT fiber 10 (unit: μm) Length of PZT fiber 10 (unit: μm) 300 300 330 400 360 500 410 600 440 700 460 800 500 900 1000

[0047] It is understandable that the specific values ​​of the inner diameter and length of the PZT fiber 10 in Table 1 are not in a one-to-one correspondence. The two are independent of each other and can be combined arbitrarily.

[0048] In this embodiment, the inner diameter of the PZT fibers 10 is set to 300 μm-500 μm. Within this range, the mechanical stress differences caused by excessively thin PZT fibers 10 are avoided, while the upper limit of the PZT fibers 10 in the composite film is also avoided by excessively thick PZT fibers 10. Setting the length of the PZT fibers 10 to 300 μm-1000 μm ensures uniform dispersion in the organic polymer, ensuring the strength and stability of the resulting piezoelectric composite film.

[0049] After preparing a PZT fiber 10 with an inner diameter of 300μm-500μm and a length of 300μm-1000μm, the PZT fiber 10 is placed in a heating furnace, and then the PZT fiber 10 is heated at a temperature of 1000℃-1300℃ for 3h-8h, so that the PZT fiber 10 is finally crystallized into a phase, thereby preventing the PZT fiber 10 from being stirred and broken up or deformed during the mixing process with the organic mixture, thereby ensuring the structural integrity of the PZT fiber 10. The heating temperature of the heating furnace in this embodiment can be, for example, 1050℃, 1100℃, 1150℃, 1200℃, 1250℃, 1300℃, etc. The heating time of the PZT fiber 10 can be, for example, 4h, 5h, 6h, 7h, etc. For example, the heating furnace in this embodiment is a muffle furnace.

[0050] 102. Compound the crystallized PZT fiber 10 with an organic polymer at a mass ratio of 1:1 to 1:4, and stir the PZT fiber 10 and the organic polymer to form a slurry.

[0051] Specifically, the mass ratio of the PZT fiber 10 to the organic polymer in this embodiment can be, for example, 1:1, 1:2, 1:3, or 1:4. A mass ratio of the PZT fiber 10 to the organic polymer within the range of 1:1 to 1:4 not only meets the minimum requirements for film formation, but also avoids fluidity issues caused by excessive organic polymer. This balances the film-forming properties and fluidity of the mixed solution, making it easier to manufacture.

[0052] During the process of mixing the PZT fibers 10 and the organic polymer, the PZT fibers 10 and the organic polymer are stirred uniformly by magnetic stirring to form a slurry.

[0053] Furthermore, a magnetic stirrer can be used to mix the PZT fibers 10 and the organic mixture. A magnetic stirrer utilizes the principle of like charges repelling and opposite charges attracting in a magnetic field, using the magnetic field to propel a magnetic stirrer placed in a container into a circular motion, thereby stirring the liquid. The magnetic stirrer not only stirs the PZT fibers 10 and the organic polymer, but also heats them during the mixing process, increasing the mixing speed and shortening the mixing time.

[0054] Furthermore, the organic mixture in this embodiment can be PDMS (polydimethylsiloxane), which has a Si-O-Si main chain and a linear dimethyl silicone oil with methyl groups attached to the silicon atoms. Due to the small intermolecular force, the molecule has a helical structure, the methyl groups are arranged outward and can rotate freely, and thus has a series of properties of silicone, such as colorless and transparent liquid, wide viscosity range, high and low temperature resistance, weather resistance, radiation resistance, low surface tension, high compressibility, resistance to oxygen plasma, high insulation, hydrophobicity, high gloss, inertness to materials, chemical and physiological inertness, etc. Polydimethyl silicone oil remains in a liquid state within a wide molar mass range (162-500000), and the viscosity can be adjusted from 0.65-1x106mm 2 / s, which is unmatched by other polymer systems. Therefore, in this embodiment, the organic mixture is set to PDMS, which can be fully mixed with the PZT fiber 10, has good insulation properties, and can ensure the dielectric constant of the finally prepared piezoelectric composite film.

[0055] Of course, in other embodiments of the present invention, the organic polymer may also be PE (polyethylene) or PP (a thermoplastic resin made by polymerizing propylene, which is a non-toxic, odorless, tasteless, highly crystalline polymer) and the like.

[0056] 103. Pour the slurry into a pre-prepared molding tank, smoothen the surface of the slurry, and bake the slurry to prepare a flat, semi-solidified piezoelectric body.

[0057] See also Figure 2 and Figure 3 As shown, before the process of preparing the piezoelectric body, it is first necessary to prepare and form a forming groove 60. The forming groove 60 can be performed before any one of step 101, step 102 or step 103.

[0058] Specifically, the forming groove 60 in this embodiment is formed by applying adhesive tape 40 to a glass plate 50. Specifically, after cleaning the surface of a 400-600 μm thick glass plate 50, multiple layers of 40-60 μm thick high-temperature adhesive tape 40 are applied according to the desired film shape and thickness to form the forming groove 60. The thickness of the glass plate 50 can be, for example, 400 μm, 450 μm, 500 μm, 550 μm, or 600 μm, and the thickness of the adhesive tape 40 can be, for example, 40 μm, 45 μm, 50 μm, 55 μm, or 60 μm.

[0059] Furthermore, the forming groove 60 in this embodiment may be a square groove, or a circular groove, a triangular groove, a pentagonal groove, or other special-shaped grooves.

[0060] After preparing the slurry, pour it onto the front end of the forming tank 60. Then, use another piece of clean glass to smooth it from front to back. Then, bake it at 50°C-150°C for 1-10 hours to obtain a flat, solidified piezoelectric block. Examples of baking temperatures include 50°C, 70°C, 100°C, 120°C, and 150°C. Examples of baking times include 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, and 10 hours.

[0061] 104. The piezoelectric body is longitudinally stretched to obtain a piezoelectric block with uniform orientation of the PZT fibers 10.

[0062] Specifically, during the stretching process of the piezoelectric body, the piezoelectric body is heated at a temperature of 100° C. to 150° C., and then cooled to obtain a piezoelectric block. The heating temperature may be, for example, 100° C., 110° C., 120° C., 130° C., 140° C., or 150° C.

[0063] See also Figure 4 As shown, longitudinally stretching the piezoelectric body under heating conditions can ensure the stretching continuity of the PZT fiber 10 and prevent the PZT fiber 10 from breaking during the stretching process.

[0064] 105. Cut the surface of the piezoelectric block to expose the PZT fibers 10 on the surface of the piezoelectric block.

[0065] See also Figure 5 As shown, in this step, a cutting machine is used to cut the piezoelectric block material with the PZT fibers 10 uniformly oriented to expose the PZT fibers 10 on the upper and lower surfaces, and then the surface is polished with 8000-10000 grit sandpaper, which can quickly make the surface of the piezoelectric block smoother, ensure that the polarization material can fully contact the piezoelectric block, and then facilitate the full polarization of the PZT fibers, thereby improving the piezoelectric coefficient of the piezoelectric composite film finally prepared.

[0066] 106. The piezoelectric block after cutting and polishing is polarized to prepare a piezoelectric composite film. The copper foil can be stably and quickly bonded to the organic polymer.

[0067] Specifically, in this step, the piezoelectric block is polarized by applying copper foil to its surface. The PZT fibers 10 passing through the piezoelectric block can directly contact the copper foil, maximizing the polarization of the PZT fibers 10 in the piezoelectric composite film and improving the piezoelectric performance of the piezoelectric composite film.

[0068] The preparation method of the piezoelectric composite film of the present invention prepares micron PZT fibers 10 by electrospinning, disperses the PZT fibers 10 in an organic polymer matrix, and uses a stretching method to stretch the PZT fibers 10 into uniformly oriented PZT fibers 10 (such as Figure 4 As shown), the piezoelectric block is then cut, polished, and polarized to form an organic, windable piezoelectric composite film (such as Figure 5 shown).

[0069] The piezoelectric composite film prepared by the preparation method has the following advantages:

[0070] (1) The piezoelectric composite film has uniformly oriented PZT fibers 10, and the PZT fibers 10 penetrate the piezoelectric composite film and can directly contact the electrode material, which can maximize the polarization of the PZT fibers 10 in the piezoelectric composite film and improve the piezoelectric performance of the piezoelectric composite film;

[0071] (2) Because the PZT fibers 10 are uniformly dispersed in the organic polymer, they have a large degree of freedom of movement and can move relative to each other without breaking or falling off. Therefore, the piezoelectric composite film has high windability.

[0072] Example 2

[0073] This embodiment provides a method for preparing a piezoelectric composite film. The method in this embodiment is basically the same as that in the first embodiment. The method for preparing a piezoelectric composite film in this embodiment is used to prepare a 1-3 type uniformly oriented PZT-organic windable piezoelectric composite film. The specific steps of the preparation method are as follows:

[0074] 101. Prepare PZT fibers with an inner diameter of 300 μm-500 μm and a diameter of 100 μm-300 μm by electrospinning, and sinter them in a muffle furnace at 700°C-1200°C for 3h-8h to crystallize the PZT fibers;

[0075] 102. Compounding the PZT fiber and the organic polymer in a mass ratio of 1:1 to 1:4, and then mixing them into a uniform slurry using a magnetic stirrer;

[0076] 103. Take a 500μm thick clean glass surface and apply multiple layers of 50μm high-temperature tape according to the shape and thickness of the 1-3 type film to form a molding groove; pour the slurry on the front end of the molding groove, use another piece of clean glass to scrape it flat from front to back, and bake it at 50℃-150℃ for 1h-10h to obtain a flat and solidified piezoelectric body;

[0077] 104. The piezoelectric body with randomly distributed PZT fibers is longitudinally stretched at a temperature of 100° C. to 150° C. to obtain a uniformly oriented 1-3 type piezoelectric block;

[0078] 105. Use a cutting machine to cut the 1-3 piezoelectric blocks with consistent orientation to expose the PZT fibers on the upper and lower surfaces, then polish the surface with 8000-10000 mesh sandpaper, and then cool at room temperature;

[0079] 106. Copper foil electrodes are applied to the upper and lower surfaces of the film for polarization.

[0080] The present invention prepares micron PZT fibers through electrospinning, disperses them in a polymer matrix, and then uses a stretching method to stretch the PZT fibers into uniformly oriented PZT fibers within a 1-3 type piezoelectric composite film. The piezoelectric film is then cut and polished to form a 1-3 type uniformly oriented PZT-organic windable piezoelectric composite film. This piezoelectric composite film maximizes the polarization of the PZT fibers within the piezoelectric composite film, improving the piezoelectric performance of the 1-3 type piezoelectric composite film. The piezoelectric composite film has a high degree of freedom of movement, allowing relative motion without breaking or falling apart, and exhibits strong windability.

[0081] Example 3

[0082] See also Figure 6 As shown, according to an embodiment of the present invention, a piezoelectric composite film is provided. The piezoelectric composite film is prepared by the preparation method of the piezoelectric composite film in embodiment 1 or embodiment 2.

[0083] Specifically, the piezoelectric composite film in this embodiment includes an organic polymer body 20 , at least two sections of PZT fibers 10 , and two electrode layers 30 .

[0084] Among them, the organic polymer body 20 has a first surface 21 and a second surface 22 opposite to the first surface 21; at least two sections of PZT fibers 10 are distributed in the organic polymer body 20, the PZT fibers 10 are oriented in the same manner and extend along the thickness direction of the organic polymer body 20, and the two ends of the PZT fibers 10 protrude from the first surface 21 and the second surface 22 respectively; the two electrode layers 30 include a first electrode layer 31 and a second electrode layer 32, the first electrode layer 31 is laid on the first surface 21 of the organic polymer body 20 and contacts the PZT fibers 10, and the second electrode layer 32 is laid on the second surface 22 of the organic polymer body 20 and contacts the PZT fibers 10.

[0085] The piezoelectric composite film in this embodiment comprises uniformly oriented PZT fibers 10, which penetrate the organic polymer matrix 20 and directly contact the electrode layer 30. This maximizes the polarization of the PZT fibers 10 within the piezoelectric composite film, thereby enhancing the piezoelectric performance of the piezoelectric composite film. Furthermore, at least two segments of PZT fibers 10 are dispersed within the organic polymer matrix 20, providing them with ample freedom of movement and enabling relative motion without breakage or loss. Consequently, the piezoelectric composite film in this embodiment exhibits high coilability.

[0086] For example, the organic polymer body 20 in this embodiment is a PDMS film layer, a PE film layer, or a PP film layer.

[0087] Furthermore, the PZT fiber 10 in this embodiment is cylindrical, and the inner diameter of the cylinder is 300 μm-500 μm, for example, 300 μm, 400 μm, 500 μm, etc.; the height is 300 μm-1000 μm, for example, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1000 μm, etc. In this embodiment, the inner diameter of the PZT fiber 10 is set to 300 μm-500 μm, and the height is 300 μm-1000 μm. Within this range, the problem of mechanical stress difference caused by setting the PZT fiber 10 too thin can be avoided, and the problem of setting the PZT fiber 10 too thick and affecting the upper limit of the PZT fiber 10 in the composite film can be avoided, thereby improving the strength and stability of the piezoelectric composite film.

[0088] Furthermore, the electrode layer 30 in this embodiment is a copper foil layer, which has a simple structure and is easily attached to the organic polymer body 20 .

[0089] The above is a detailed introduction to a piezoelectric composite film and a preparation method thereof disclosed in an embodiment of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the core idea of ​​a piezoelectric composite film and a preparation method thereof of the present invention; at the same time, for general technical personnel in this field, based on the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for preparing a piezoelectric composite film, characterized in that: include: preparing a PZT fiber having an inner diameter of 300 μm to 500 μm and a length of 300 μm to 1000 μm, and crystallizing the PZT fiber; Compounding the crystallized PZT fiber with PDMS in a mass ratio of 1:1 to 1:4, and uniformly stirring the PZT fiber and PDMS to form a slurry; Pour the slurry into a pre-prepared forming tank, smoothen the surface of the slurry, and then bake the slurry to prepare a piezoelectric body; The piezoelectric body is longitudinally stretched to obtain a piezoelectric block with consistent PZT fiber orientation; cutting the surface of the piezoelectric block so that the PZT fibers are exposed on the upper and lower surfaces of the piezoelectric block; The cut piezoelectric blocks are polarized to prepare a piezoelectric composite film.

2. The method for preparing a piezoelectric composite film according to claim 1, wherein: The PZT fiber is prepared by using at least one of an electrospinning method, an extrusion molding method, and a condensation water bath method.

3. The method for preparing a piezoelectric composite film according to claim 1, wherein: The process of preparing a PZT fiber having an inner diameter of 300 μm to 500 μm and a length of 300 μm to 1000 μm and crystallizing the PZT fiber into a phase includes the following steps: Prepare PZT fibers with an inner diameter of 300 μm-500 μm and a length of 300 μm-1000 μm; placing the PZT fiber into a heating furnace; The PZT fiber is heated at a temperature of 1000° C. to 1300° C. for 3 to 8 hours in the heating furnace to crystallize the PZT fiber.

4. The method for preparing a piezoelectric composite film according to claim 1, wherein: The PZT fibers and the PDMS are uniformly stirred by magnetic force to form a slurry.

5. The method for preparing a piezoelectric composite film according to claim 1, wherein: The forming groove is formed by sticking and surrounding the glass plate with adhesive tape.

6. The method for preparing a piezoelectric composite film according to claim 1, wherein: The piezoelectric body is obtained by baking at a temperature of 50° C. to 150° C. for 1 hour to 10 hours.

7. The method for preparing a piezoelectric composite film according to claim 1, wherein: During the stretching of the piezoelectric body, the piezoelectric body is heated at a temperature of 100° C. to 150° C.

8. The method for preparing a piezoelectric composite film according to claim 1, wherein: After cutting the piezoelectric block and before polarizing the piezoelectric block, the piezoelectric block is polished using 8000-10000 mesh sandpaper.

9. The method for preparing a piezoelectric composite film according to any one of claims 1 to 8, characterized in that: The piezoelectric block is polarized by applying copper foil on the surface of the piezoelectric block.

10. A piezoelectric composite film, characterized in that: The piezoelectric composite film is prepared by the method for preparing a piezoelectric composite film according to any one of claims 1 to 9, and the piezoelectric composite film comprises: a PDMS body comprising a first surface and a second surface opposite to the first surface; At least two sections of PZT fibers, the PZT fibers being distributed in the PDMS body, the PZT fibers being uniformly oriented and extending along the thickness direction of the PDMS body, and two ends of the PZT fibers protruding from the first surface and the second surface, respectively; and Two electrode layers, the two electrode layers include a first electrode layer and a second electrode layer, the first electrode layer is laid on the first surface and contacts the PZT fiber, and the second electrode layer is laid on the second surface and contacts the PZT fiber.

11. The piezoelectric composite film according to claim 10, characterized in that: The PZT fiber is cylindrical, and the inner diameter of the cylinder is 300 μm-500 μm, and the height is 300 μm-1000 μm.

12. The piezoelectric composite film according to claim 10 or 11, characterized in that: The electrode layer is a copper foil layer.

Images