A flexible stretchable piezoelectric composite material, its 3D printing method and application

Abstract

This invention relates to the field of additive manufacturing technology, and discloses a flexible tensile piezoelectric composite material, its preparation method, and its application. The method includes: (1) mixing the components of a solvent and slurry raw material composition to obtain a slurry; the solid content of the slurry is 70-85 wt% based on the total weight of the slurry; (2) 3D printing the slurry; the 3D printing is performed using a pre-programmed file, which is a code file that sets the number of support structure layers to 1-3 and the included angle between any two adjacent layers of the support structure to 0°-180°. The method for preparing flexible piezoelectric fiber composite materials provided by this invention allows for arbitrary adjustment of the support structure angle, enabling the design of the three-dimensional structure of the flexible piezoelectric fiber composite material, as well as the design and control of the equivalent piezoelectric coefficient of the piezoelectric composite; it also eliminates the ceramic cutting step, improving preparation efficiency and avoiding environmental pollution.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, specifically to a flexible stretchable piezoelectric composite material, its 3D printing method, and its applications. Background Technology

[0002] Flexible piezoelectric fiber composites possess excellent flexibility, maintaining the high piezoelectric properties of piezoelectric ceramics while overcoming the shortcomings of traditional piezoelectric ceramic materials, such as high brittleness, poor toughness, and difficulty in applying them to complex shapes. They represent a high-performance integrated sensing and actuation material. Currently, flexible piezoelectric fiber composites are widely used in actuation, sensing, and structural health monitoring.

[0003] The traditional fabrication process for flexible piezoelectric fiber composites is complex, mainly involving ceramic sheet preparation, sintering, cutting, resin filling, thinning, and encapsulation. One significant step is the generation of lead-containing dust during the cutting of lead zirconate titanate ceramics, which inevitably causes environmental pollution. Furthermore, traditional stretched flexible piezoelectric fiber composites suffer from poor shape versatility. Specifically, irregular shapes and non-standard samples require separate preparation of ceramic sheets, and larger samples are difficult to process, resulting in lengthy and time-consuming processes. Additionally, the piezoelectric ceramic framework within the composite lacks a three-dimensional structural design.

[0004] CN105405963A discloses a gradient piezoelectric fiber composite material and its preparation method. This material is prepared using a cut-and-fill method and consists of two interlaced finger electrodes, piezoelectric fibers, and a polymer. The piezoelectric fibers and polymer are arranged alternately, and the volume fraction of a single piezoelectric fiber exhibits a continuous gradient along the transverse direction of the composite material. This composite material possesses high flexibility and excellent piezoelectric actuation properties. However, this technology is still based on the traditional cut-and-fill process, which suffers from drawbacks such as environmental pollution, poor shape diversity, lack of structural design, and low preparation efficiency.

[0005] Currently, the development of additive manufacturing technology (also known as 3D printing technology) has greatly reduced the processing difficulty of complex-shaped ceramic devices. 3D printing technology not only easily prints complex shapes and structures, but also can directly prepare the ceramic framework in composites. Summary of the Invention

[0006] The purpose of this invention is to solve the problems of poor shape diversity and lack of three-dimensional structural design caused by the processing difficulties in the existing flexible piezoelectric fiber composite material preparation process, and to overcome the environmental pollution caused by cutting lead zirconate titanate ceramics in the existing preparation process.

[0007] To achieve the above objectives, a first aspect of the present invention provides a 3D printing method for flexible tensile piezoelectric composite materials, the method comprising the following steps:

[0008] (1) The solvent and the components in the slurry raw material composition are mixed to obtain a slurry; the solid content of the slurry is 70-85 wt% based on the total mass of the slurry.

[0009] (2) The slurry is subjected to 3D printing; the 3D printing is performed under a pre-programmed file, which is a code file that sets "the number of support structure layers is 1-3" and "the included angle between any two adjacent layers of the support structure is 0°-180°".

[0010] The 3D printing process is performed using a needle with an inner diameter of 100-800 μm, and the conditions for the 3D printing process must at least meet the following requirements: extrusion pressure of 0.1-0.7 MPa.

[0011] In step (1), the solvent is selected from deionized water, 1,2-dimethylbenzene or anhydrous ethanol; the slurry raw material composition contains piezoelectric ceramic powder, binder, plasticizer and dispersant; in the slurry raw material composition, the mass ratio of the piezoelectric ceramic powder, the binder, the plasticizer and the dispersant is 1:0.03-0.2:0.01-0.03:0.01-0.03.

[0012] A second aspect of the present invention provides a flexible tensile piezoelectric composite material prepared by the method described in the first aspect of the present invention.

[0013] The third aspect of the present invention provides the application of the flexible tensile piezoelectric composite material described in the second aspect of the present invention in the fields of actuation, sensing, structural health monitoring, vibration suppression and energy harvesting.

[0014] The method for preparing flexible piezoelectric fiber composite materials provided by this invention also has at least the following beneficial effects:

[0015] (1) The method provided by the present invention can adjust the angle of the support structure to realize the design of the three-dimensional structure of the flexible piezoelectric fiber composite material, and realize the design and control of the equivalent piezoelectric coefficient of the piezoelectric composite.

[0016] (2) The method provided by the present invention eliminates the ceramic cutting step, improves the preparation efficiency, and avoids environmental pollution.

[0017] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0018] Figure 1This is a three-dimensional structural schematic diagram of the flexible tensile piezoelectric composite material obtained in Embodiment 1 of the present invention;

[0019] Figure 2 This is a free strain curve of the flexible tensile piezoelectric composite material obtained in Example 1 of the present invention;

[0020] Figure 3 This is a free strain curve of the flexible tensile piezoelectric composite material obtained in Example 2 of the present invention;

[0021] Figure 4 This is an optical photograph of the support structure of the flexible tensile piezoelectric composite material obtained in Embodiment 1 of the present invention;

[0022] Figure 5 This is an optical photograph of the support structure of the flexible tensile piezoelectric composite material obtained in Embodiment 2 of the present invention. Detailed Implementation

[0023] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0024] In this invention, PZT-type piezoelectric ceramic powder refers to lead zirconate titanate piezoelectric ceramic powder.

[0025] As previously described, a first aspect of the present invention provides a 3D printing method for flexible tensile piezoelectric composite materials, the method comprising the following steps:

[0026] (1) The solvent and the components in the slurry raw material composition are mixed to obtain a slurry; the solid content of the slurry is 70-85 wt% based on the total mass of the slurry.

[0027] (2) The slurry is subjected to 3D printing; the 3D printing is performed under a pre-programmed file, which is a code file that sets "the number of support structure layers is 1-3" and "the included angle between any two adjacent layers of the support structure is 0°-180°".

[0028] The 3D printing process is performed using a needle with an inner diameter of 100-800 μm, and the conditions for the 3D printing process must at least meet the following requirements: extrusion pressure of 0.1-0.7 MPa.

[0029] In step (1), the solvent is selected from deionized water, 1,2-dimethylbenzene or anhydrous ethanol; the slurry raw material composition contains piezoelectric ceramic powder, binder, plasticizer and dispersant; in the slurry raw material composition, the mass ratio of the piezoelectric ceramic powder, the binder, the plasticizer and the dispersant is 1:0.03-0.2:0.01-0.03:0.01-0.03.

[0030] In a preferred embodiment, in step (2), the method further includes: defoaming the slurry before performing the 3D printing process.

[0031] Preferably, the defoaming treatment conditions at least satisfy the following: time of 2-5 minutes and rotation speed of 1500-2500 rpm.

[0032] The present invention does not impose any particular limitation on the defoaming treatment method. For example, the defoaming treatment is performed by a rotary defoamer.

[0033] Preferably, in step (2), the 3D printing process is performed using a needle with an inner diameter of 200-400 μm. The inventors of this invention have discovered that under these preferred conditions, the prepared flexible tensile piezoelectric composite material exhibits good flexibility.

[0034] In this invention, the inner diameter of the needle is an important factor in obtaining the flexible tensile piezoelectric composite material. When the inner diameter of the needle is too large, the thickness of the obtained flexible tensile piezoelectric composite material is too large, and the flexibility and free strain performance of the composite material deteriorate.

[0035] In a preferred embodiment, in step (2), the 3D printing process conditions must at least satisfy: the extrusion pressure is 0.3-0.6 MPa. The inventors of this invention have discovered that under these preferred conditions, the prepared flexible tensile piezoelectric composite material has a specific three-dimensional structure, and the structure of this composite material is not prone to defects or deformation. Specifically, the obtained flexible tensile piezoelectric composite material has a support structure with a specific number of layers, and any two adjacent layers have the same specific angle.

[0036] In this invention, the extrusion pressure is an important factor in obtaining the flexible tensile piezoelectric composite material. When the extrusion pressure is too high, the extrusion speed of the slurry is too fast, and the resulting flexible tensile piezoelectric composite material does not have a specific three-dimensional structure or cannot form a three-dimensional structure, and the free strain performance of the composite material deteriorates.

[0037] More preferably, in step (2), the 3D printing process is performed under a pre-programmed file, which is a code file that sets "the number of support structure layers is 2" and "the included angle between the two layers of the support structure is 30°-120°".

[0038] In a preferred embodiment, the pre-programmed file is configured using AutoCAM software.

[0039] In a preferred embodiment, in step (1), the amount of solvent used is 0.5-1 mL relative to 1 g of the piezoelectric ceramic powder.

[0040] Preferably, in step (1), the mass ratio of the piezoelectric ceramic powder, the binder, the plasticizer, and the dispersant in the slurry raw material composition is 1:0.03-0.1:0.01-0.025:0.01-0.015. The inventors of this invention have discovered that under these preferred conditions, the obtained slurry exhibits optimal shear-thinning properties and a modulus capable of maintaining its shape, thereby producing a flexible, tensile piezoelectric composite material with a highly accurate three-dimensional structure.

[0041] Preferably, in step (1), the piezoelectric ceramic powder in the slurry raw material composition is a PZT type piezoelectric ceramic powder, and the average particle size of the piezoelectric ceramic powder is 0.1-1 μm.

[0042] More preferably, in step (1), the binder in the slurry raw material composition is polyvinyl butyral or polyvinyl alcohol.

[0043] More preferably, in step (1), the plasticizer in the slurry raw material composition is selected from at least one of dibutyl phthalate, polyethylene glycol, and glycerol.

[0044] Preferably, in step (1), the dispersant in the slurry raw material composition is triethyl phosphate or ammonium polyacrylate.

[0045] In a preferred embodiment, the mixing process in step (1) is carried out in a ball mill jar.

[0046] Preferably, in step (1), the conditions for the mixing process are at least: a rotation speed of 100-500 rpm and a time of 12-48 h.

[0047] Preferably, in step (1), the method further includes: concentrating the mixture obtained by the mixing process.

[0048] In a preferred embodiment, the concentration process is carried out under stirring, and the conditions for the concentration process are at least: a rotation speed of 300-400 rpm, a temperature of 60-90°C, and a time of 2-10 h.

[0049] According to a preferred embodiment, the method further includes: sequentially performing drying, sintering, curing, encapsulation, and polarization treatments on the intermediate product obtained from 3D printing.

[0050] Preferably, the drying conditions at least satisfy the following: the time is 24-72 hours.

[0051] In a preferred embodiment, the sintering process is carried out in a lead-containing air atmosphere, which is provided by PZT powder, and the conditions of the sintering process are at least: a heating rate of 3-5℃ / min, a temperature of 1200-1300℃, and a holding time of 2-4h.

[0052] Preferably, the PZT powder is laid at the bottom of the intermediate product after the drying treatment, the thickness of the PZT powder is 1 cm, and the average particle size of the PZT powder is 10 μm.

[0053] It should be noted that in the sintering process, the holding time is the time required at the stated temperature, excluding the time used for the heating process.

[0054] Preferably, the curing process is carried out in epoxy resin, and the curing conditions at least meet the following requirements: time of 12-48 hours and temperature of 25-60°C.

[0055] The present invention does not impose any particular limitation on the amount of epoxy resin used. For example, in the curing process, the amount of epoxy resin used is 3-5g.

[0056] In a preferred embodiment, the method further includes: after the curing process and before the encapsulation process, grinding the obtained intermediate I to obtain intermediate II.

[0057] Preferably, the polishing conditions should at least meet the following requirements: time of 30-40 minutes and rotation speed of 55-65 rpm.

[0058] The present invention does not have any special requirements for the grinding process, as long as the epoxy resin in the intermediate I exposes the upper and lower ceramic fibers. For example, the grinding process is carried out by a polishing machine.

[0059] Preferably, the encapsulation process involves first applying epoxy resin to both sides of the exposed ceramic fibers of the intermediate II, then attaching interdigitated electrode sheets to both sides coated with epoxy resin, and finally encapsulating the material under a pressure of 0.05-5 MPa and a temperature of 80-120°C for 20-30 minutes.

[0060] The present invention does not impose any particular limitation on the amount of epoxy resin adhesive used, as long as it is sufficient to coat both sides of the intermediate II exposed ceramic fiber. For example, the amount of epoxy resin adhesive used on either side is 0.1-0.5g.

[0061] More preferably, the polarization treatment conditions at least satisfy: DC voltage of 1-2.5kV and time of 15-30min.

[0062] As previously stated, a second aspect of the present invention provides a flexible tensile piezoelectric composite material prepared by the method described in the first aspect of the present invention.

[0063] As previously stated, the third aspect of the present invention provides the application of the flexible tensile piezoelectric composite material described in the second aspect of the present invention in the fields of actuation, sensing, structural health monitoring, vibration suppression and energy harvesting.

[0064] The present invention will be described in detail below through examples. In the following examples, unless otherwise specified, the raw materials are all commercially available products.

[0065] Among them, piezoelectric ceramic powder:

[0066] PZT-5A piezoelectric ceramic powder has an average particle size of 0.5μm.

[0067] The interdigitated electrode has an interdigitated coverage area of ​​28mm × 7mm and an interdigitated spacing of 550μm.

[0068] In the following example, the 3D printing process is performed in a direct-write 3D printer, which is purchased from Changsha Nayi Instrument Technology Co., Ltd., and the model number is JDX01.

[0069] The ball mill jar, model 100mL, was purchased from Hunan Changsha Miqi MITR Instrument Co., Ltd.

[0070] In the following examples, unless otherwise specified, the room temperature is 25±2℃.

[0071] In the following example, the lead-containing air atmosphere is provided by PZT powder, which is laid on the bottom of the intermediate product after the drying process. The thickness of the PZT powder is 1 cm, and the average particle size of the PZT powder is 10 μm.

[0072] Example 1

[0073] This example provides a 3D printing method for flexible, stretched piezoelectric composite materials, which includes the following steps:

[0074] (1) 15 mL of 1,2-dimethylbenzene was added to a mixture containing 30 g of PZT-5A piezoelectric ceramic powder, 1.0 g of polyvinyl butyral, 0.2 g of polyethylene glycol, 0.2 g of dibutyl phthalate, and 0.3 g of triethyl phosphate, and the mixture was then mixed and concentrated to obtain a slurry. Based on the total mass of the slurry, the solid content of the slurry was 85 wt%.

[0075] The mixing process is carried out in a ball mill jar, and the conditions for the mixing process are: a rotation speed of 100 rpm and a time of 24 h.

[0076] The concentration process is carried out under stirring, and the conditions for the concentration process are: temperature of 60°C, time of 5 hours, and rotation speed of 400 rpm.

[0077] (2) The slurry is subjected to defoaming treatment and 3D printing treatment in sequence to obtain an intermediate product with a two-layer support structure, and the included angle between the two-layer support structure of the intermediate product is 90°.

[0078] The defoaming process is carried out in a rotary defoamer, and the conditions for the defoaming process are: time is 2 minutes and rotation speed is 2000 rpm.

[0079] The 3D printing process is performed under a pre-compiled program file, which is a code file that uses Auto CAM software to set "the number of support structure layers is 2" and "the included angle between the two layers of the support structure is 90°".

[0080] The 3D printing process is performed using a needle with an inner diameter of 400 μm, and the conditions for the 3D printing process are: extrusion pressure of 0.4 MPa;

[0081] (3) The intermediate product is subjected to drying, sintering, curing, polishing, encapsulation and polarization treatment in sequence to obtain a flexible tensile piezoelectric composite material.

[0082] The drying process is performed at room temperature for 24 hours; the sintering process is carried out in a lead-containing air atmosphere, and the conditions for the sintering process are: heating rate of 3℃ / min, temperature of 1200℃, and holding time of 2 hours.

[0083] The curing process is carried out in 3g of epoxy resin, and the curing conditions are: temperature 25℃, time 48h; the polishing process is carried out using a polishing machine to expose the ceramic fibers and obtain intermediate II; the polishing conditions are: time 30min, speed 60rpm.

[0084] The encapsulation process involves first applying epoxy resin adhesive to both sides of the exposed ceramic fibers of intermediate II (based on the total weight of intermediate II, the amount of epoxy resin adhesive used on any side is 0.1g), then attaching interdigital electrode sheets to both sides coated with epoxy resin adhesive, and then encapsulating the material at a pressure of 0.05MPa and a temperature of 80℃ for 20 minutes.

[0085] The polarization treatment is performed at room temperature, and the conditions for the polarization treatment are: DC voltage of 2kV and time of 20min.

[0086] Example 2

[0087] This example provides a method for preparing flexible, tensile piezoelectric composite materials, which includes the following steps:

[0088] (1) Add 20 mL of deionized water to a mixture containing 20 g of PZT-5A piezoelectric ceramic powder, 1.5 g of polyvinyl alcohol, 0.3 g of glycerol, 0.2 g of dibutyl phthalate, and 0.3 g of ammonium polyacrylate, and perform mixing and concentration treatments in sequence to obtain a slurry; the solid content of the slurry is 70 wt% based on the total mass of the slurry.

[0089] The mixing process is carried out in a ball mill jar, and the conditions for the mixing process are: a rotation speed of 500 rpm and a time of 12 h.

[0090] The concentration process is carried out under stirring, and the conditions for the concentration process are: temperature of 90°C, time of 2 hours, and rotation speed of 400 rpm.

[0091] (2) The slurry is subjected to defoaming treatment and 3D printing treatment in sequence to obtain an intermediate product with a two-layer support structure, and the included angle between the two-layer support structure of the intermediate product is 120°.

[0092] The defoaming process is carried out in a rotary defoamer, and the conditions for the defoaming process are: time is 3 minutes and rotation speed is 2500 rpm.

[0093] The 3D printing process is performed under a pre-compiled program file, which is a code file that uses Auto CAM software to set "the number of support structure layers is 2" and "the included angle between the two layers of the support structure is 120°".

[0094] The 3D printing process is performed using a needle with an inner diameter of 250 μm, and the conditions for the 3D printing process are: an extrusion pressure of 0.6 MPa.

[0095] (3) The intermediate product is subjected to drying, sintering, curing, polishing, encapsulation and polarization treatment in sequence to obtain a flexible tensile piezoelectric composite material.

[0096] The drying process is performed at room temperature for 48 hours; the sintering process is carried out in a lead-containing air atmosphere, and the conditions for the sintering process are: heating rate of 5℃ / min, temperature of 1300℃, and holding time of 3 hours.

[0097] The curing process is carried out in 5g of epoxy resin, and the curing conditions are: temperature 45℃, time 12h; the polishing process is carried out using a polishing machine to expose the ceramic fibers and obtain intermediate II; the polishing conditions are: time 35min, speed 55rpm.

[0098] The encapsulation process involves first applying epoxy resin adhesive to both sides of the exposed ceramic fibers of intermediate II (based on the total weight of intermediate II, the amount of epoxy resin adhesive used on any side is 0.3g), then attaching interdigital electrode sheets to both sides coated with epoxy resin adhesive, and then encapsulating the material at a pressure of 5MPa and a temperature of 120℃ for 30min.

[0099] The polarization treatment is performed at room temperature, and the conditions for the polarization treatment are: DC voltage of 1kV and time of 30min.

[0100] Example 3

[0101] This example provides a method for preparing flexible, tensile piezoelectric composite materials, which includes the following steps:

[0102] (1) Add 20 mL of deionized water to a mixture containing 20 g of PZT-5A piezoelectric ceramic powder, 2 g of polyvinyl alcohol, 0.1 g of glycerol, 0.1 g of dibutyl phthalate, and 0.2 g of triethyl phosphate, and perform mixing and concentration treatments in sequence to obtain a slurry; the solid content of the slurry is 80 wt% based on the total mass of the slurry.

[0103] The mixing process is carried out in a ball mill jar, and the conditions for the mixing process are: a rotation speed of 300 rpm and a time of 48 h.

[0104] The concentration process is carried out under stirring, and the conditions for the concentration process are: temperature of 80°C, time of 10 hours, and rotation speed of 300 rpm.

[0105] (2) The slurry is subjected to defoaming treatment and 3D printing treatment in sequence to obtain an intermediate product with a two-layer support structure, and the included angle between the two-layer support structure of the intermediate product is 30°.

[0106] The defoaming process is carried out in a rotary defoamer, and the conditions for the defoaming process are: time of 5 minutes and rotation speed of 1500 rpm.

[0107] The 3D printing process is performed under a pre-compiled program file, which is a code file that uses Auto CAM software to set "the number of support structure layers is 2" and "the included angle between the two layers of the support structure is 30°".

[0108] The 3D printing process is performed using a needle with an inner diameter of 200 μm, and the conditions for the 3D printing process are: an extrusion pressure of 0.3 MPa.

[0109] (3) The intermediate product is subjected to drying, sintering, curing, polishing, encapsulation and polarization treatment in sequence to obtain a flexible tensile piezoelectric composite material.

[0110] The drying process is performed at room temperature for 72 hours; the sintering process is carried out in a lead-containing air atmosphere, and the conditions for the sintering process are: heating rate of 5℃ / min, temperature of 1250℃, and holding time of 4 hours.

[0111] The curing process is carried out in 5g of epoxy resin, and the curing conditions are: temperature 60℃, time 24h; the polishing process is carried out using a polishing machine to expose the ceramic fibers to obtain intermediate II; the polishing conditions are: time 40min, speed 65rpm.

[0112] The encapsulation process involves first applying epoxy resin adhesive to both sides of the exposed ceramic fibers of intermediate II (based on the total weight of intermediate II, the amount of epoxy resin adhesive used on any side is 0.5g), then attaching interdigital electrode sheets to both sides coated with epoxy resin adhesive, and then encapsulating the material under a pressure of 1.5MPa and a temperature of 100℃ for 20min.

[0113] The polarization treatment is performed at room temperature, and the conditions for the polarization treatment are: DC voltage of 2.5kV and time of 15min.

[0114] Example 4

[0115] In this example, a flexible tensile piezoelectric composite material was prepared according to the method of Example 1. The difference is that in step (2), the 3D printing process was carried out through a needle with an inner diameter of 800 μm. The remaining steps and parameters are the same as in Example 1.

[0116] Example 5

[0117] In this example, a flexible tensile piezoelectric composite material was prepared according to the method of Example 1. The difference is that in step (2), the extrusion pressure of the 3D printing process is 0.7 MPa, and the remaining steps and parameters are the same as in Example 1.

[0118] Comparative Example 1

[0119] In this example, a flexible tensile piezoelectric composite material was prepared according to the method of Example 1. The difference is that in step (2), the 3D printing process was carried out through a needle with an inner diameter of 1000 μm. The remaining steps and parameters are the same as in Example 1.

[0120] Comparative Example 2

[0121] In this example, a flexible tensile piezoelectric composite material was prepared according to the method of Example 1. The difference is that in step (2), the extrusion pressure of the 3D printing process is 0.8 MPa, and the remaining steps and parameters are the same as in Example 1.

[0122] Test case

[0123] The flexible tensile piezoelectric composite materials prepared in the above embodiments and comparative examples were tested, and the results are shown in Table 1.

[0124] Table 1

[0125]

[0126] In Table 1, the longitudinal and transverse free strains were obtained under the condition of a driving voltage of -500-500V.

[0127] As can be seen from the results in Table 1, the flexible tensile piezoelectric composite material prepared in the embodiments of the present invention has a significantly more suitable thickness and good free strain capability under the same driving voltage.

[0128] Furthermore, as can be seen from the results in Table 1, by adjusting the support structure angle of the composite material, the embodiments of the present invention can make the obtained composite material have different equivalent piezoelectric coefficients.

[0129] To more clearly illustrate the flexible, stretchable piezoelectric composite material obtained by the present invention, by way of example, the present invention... Figure 1 This invention illustrates a three-dimensional structural schematic diagram of the flexible tensile piezoelectric composite material obtained in Embodiment 1 of the present invention. The present invention utilizes… Figure 2The free strain curve of the flexible tensile piezoelectric composite material obtained in Example 1 of the present invention is shown. The present invention, through... Figure 3 The free strain curve of the flexible tensile piezoelectric composite material obtained in Example 2 of the present invention is shown. The present invention, through... Figure 4 An optical photograph of the support structure of the flexible tensile piezoelectric composite material obtained in Embodiment 1 of the present invention is shown; the present invention... Figure 5 An optical photograph of the support structure of the flexible tensile piezoelectric composite material obtained in Embodiment 2 of the present invention is shown.

[0130] Among them, by Figure 1 As can be seen, the flexible tensile piezoelectric composite material obtained in Embodiment 1 of the present invention includes two layers of interdigitated electrode sheets, a PZT ceramic support, and an epoxy resin layer.

[0131] Depend on Figure 2 It can be seen that, under the condition of driving voltage of -500-500V, the maximum longitudinal free strain of the flexible tensile piezoelectric composite material obtained in Example 1 of the present invention is 733ppm and the maximum transverse free strain is 273ppm.

[0132] Depend on Figure 3 It can be seen that, under the condition of a driving voltage of -500-500V, the longitudinal and transverse free strain directions of the flexible tensile piezoelectric composite material obtained in Example 2 of the present invention are consistent, that is, the equivalent piezoelectric coefficient d 31 The value is >0, and the maximum longitudinal free strain of the composite material is 55ppm, and the maximum transverse free strain is 345ppm.

[0133] Depend on Figure 4 It can be seen that the flexible tensile piezoelectric composite material obtained in Example 1 of the present invention has a two-layer support structure, and the included angle between the two support structures is 90°.

[0134] Depend on Figure 5 It can be seen that the flexible tensile piezoelectric composite material obtained in Example 2 of the present invention has a two-layer support structure, and the included angle between the two support structures is 120°.

[0135] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A 3D printing method of a flexible stretch piezoelectric composite material, characterized in that, The method includes the following steps: (1) The solvent and slurry raw material composition are mixed to obtain a slurry; the solid content of the slurry is 80-85 wt% based on the total mass of the slurry. (2) The slurry is subjected to 3D printing; the 3D printing is performed under a pre-programmed file, which is a code file that sets "the number of support structure layers is 2" and "the included angle between any two adjacent layers of the support structure is 120°"; the pre-programmed file is set using Auto CAM software; The 3D printing process is performed using a needle with an inner diameter of 200-400 μm, and the conditions for the 3D printing process must at least meet the following requirements: extrusion pressure of 0.3-0.6 MPa. In step (1), the solvent is 1,2-dimethylbenzene; the slurry raw material composition contains piezoelectric ceramic powder, binder, plasticizer, and dispersant; in the slurry raw material composition, the mass ratio of the piezoelectric ceramic powder, the binder, the plasticizer, and the dispersant is 1:0.03-0.2:0.01-0.03:0.01-0.03; The piezoelectric ceramic powder is a PZT type piezoelectric ceramic powder, and the average particle size of the piezoelectric ceramic powder is 0.1-1μm.

2. The method of claim 1, wherein, In step (1), the binder in the slurry raw material composition is polyvinyl butyral or polyvinyl alcohol; And / or, in step (1), the plasticizer in the slurry raw material composition is selected from at least one of dibutyl phthalate, polyethylene glycol, and glycerol; And / or, in step (1), the dispersant in the slurry raw material composition is triethyl phosphate or ammonium polyacrylate.

3. The method of claim 1 or 2, wherein, In step (1), the conditions for the mixing process must at least be: a rotation speed of 100-500 rpm and a time of 12-48 h.

4. The method of claim 1 or 2, wherein, The method further includes: sequentially performing drying, sintering, curing, encapsulation, and polarization treatments on the intermediate products obtained from 3D printing.

5. A flexible tensile piezoelectric composite material prepared by the method according to any one of claims 1-4.

6. The application of the flexible tensile piezoelectric composite material as described in claim 5 in the fields of driving, sensing, structural health monitoring, vibration suppression and energy harvesting.

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