Flexible piezoelectric sensor packaged by fish scale microstructure elastomer and preparation method thereof

Abstract

The embodiment of the invention discloses a flexible piezoelectric sensor packaged by a fish scale microstructure elastomer and a preparation method thereof, the flexible piezoelectric sensor is provided with a flexible main body structure, the flexible main body structure comprises a first packaging layer, a piezoelectric layer, an electrode layer and a second packaging layer, the central area of the first packaging layer is provided with a rectangular notch, and the piezoelectric layer is arranged in the rectangular notch; a rectangular notch is formed in the first packaging layer, an elastomer packaging layer covers the rectangular notch, the elastomer packaging layer comprises a substrate and a fish scale microstructure, and the stress distribution effect of the elastomer packaging layer is optimized through the fish scale microstructure, so that the composite packaging structure of the first packaging layer and the elastomer packaging layer can guide stress to be concentrated in a specific area; the flexible piezoelectric sensor has the advantages that the flexible piezoelectric sensor is provided with the fish scale microstructure, local strain capacity is enhanced, energy dissipation is reduced, the fish scale microstructure comprises a plurality of fish scale microstructure units, the fish scale microstructure units are arranged in an array mode, and sensitivity and response speed of the flexible piezoelectric sensor under the low-pressure or low-frequency condition are further improved.

Description

Technical Field

[0001] The present disclosure relates to the field of piezoelectric technology, and in particular to a flexible piezoelectric sensor encapsulated by a fish-scale microstructure elastomer and a preparation method thereof. Background Art

[0002] In practical applications, flexible piezoelectric sensors are an important auxiliary tool in the fields of health monitoring and human physiological characteristics identification. These application scenarios place higher demands on the mechanical properties and sensitivity of flexible piezoelectric sensors. Currently, an effective way to improve sensing performance is to integrate elastomer packaging design into flexible piezoelectric sensors and use methods to prepare planar structures or homogeneous structures to achieve the packaging of flexible piezoelectric sensors. However, when the planar or homogeneous structure packaging method is subjected to complex stress for a long time, it is easy to cause material fatigue or interface delamination due to local stress concentration, which reduces signal stability and affects the sensitivity and response speed of the piezoelectric sensor. Summary of the Invention

[0003] The following is an overview of the subject matter described in detail in this disclosure. This overview is not intended to limit the scope of the claims.

[0004] The embodiments of the present disclosure provide a flexible piezoelectric sensor encapsulated in an elastomer with a fish scale microstructure and a preparation method thereof. The stress distribution effect of the elastomer encapsulation layer is optimized through the fish scale microstructure, so that the composite encapsulation structure of the first encapsulation layer and the elastomer encapsulation layer can guide the stress to concentrate in a specific area, enhance local strain capacity and reduce energy dissipation, and improve the sensitivity and response speed of the flexible piezoelectric sensor encapsulated in an elastomer with a fish scale microstructure under low pressure or low frequency conditions.

[0005] In one aspect, an embodiment of the present disclosure provides a flexible piezoelectric sensor encapsulated in a fish-scale microstructure elastomer, comprising:

[0006] A flexible main body structure includes a first packaging layer, a piezoelectric layer, an electrode layer and a second packaging layer. A rectangular notch is opened in the central area of the first packaging layer, and an elastomer packaging layer is covered above the rectangular notch. The elastomer packaging layer includes a substrate and a fish-scale microstructure. The fish-scale microstructure includes a plurality of fish-scale microstructure units, and the plurality of fish-scale microstructure units are arranged in an array.

[0007] On the other hand, the present disclosure also provides a method for preparing a flexible piezoelectric sensor encapsulated by a fish scale microstructure elastomer, comprising:

[0008] preparing a light-curing solution, adding the light-curing solution to a light-curing 3D printing platform, and performing layer-by-layer printing under continuous exposure to ultraviolet light set on the light-curing 3D printing platform to obtain the elastomer encapsulation layer;

[0009] Obtaining a low-viscosity polyimide tape and a glass slide, attaching the low-viscosity polyimide tape to the glass slide, and performing laser cutting according to the size of the first encapsulation layer and the size of the second encapsulation layer to obtain the first encapsulation layer and the second encapsulation layer;

[0010] A L-polylactic acid mixed solution is prepared, and the L-polylactic acid mixed solution is uniformly dripped into a piezoelectric layer mold for natural air drying to obtain the piezoelectric layer, and an electrode template is attached to the piezoelectric layer and then a double-sided silver electrode operation is performed to obtain a piezoelectric layer electrode;

[0011] The piezoelectric layer electrode is welded to the flexible circuit cable, the welded piezoelectric layer is attached to the first packaging layer and the second packaging layer respectively, and the elastomer packaging layer is covered on the rectangular notch of the first packaging layer to obtain the flexible piezoelectric sensor with fish scale microstructure elastomer packaging.

[0012] The embodiments of the present disclosure include at least the following beneficial effects: a flexible main body structure is provided, the flexible main body structure includes a first packaging layer, a piezoelectric layer, an electrode layer and a second packaging layer, a rectangular notch is opened in the central area of the first packaging layer, and an elastomer packaging layer is covered above the rectangular notch, the elastomer packaging layer includes a substrate and a fish-scale microstructure, and the stress distribution effect of the elastomer packaging layer is optimized by the fish-scale microstructure, so that the composite packaging structure of the first packaging layer and the elastomer packaging layer can guide the stress to concentrate in a specific area, enhance local strain capacity and reduce energy dissipation, and at the same time, the fish-scale microstructure includes a plurality of fish-scale microstructure units, and the plurality of fish-scale microstructure units are arranged in an array, which further improves the sensitivity and response speed of the flexible piezoelectric sensor encapsulated by the fish-scale microstructure elastomer under low pressure or low frequency conditions.

[0013] Other features and advantages of the present disclosure will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practicing the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings are used to provide a further understanding of the technical solution of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the technical solution of the present disclosure and do not constitute a limitation to the technical solution of the present disclosure.

[0015] Figure 1 An optional schematic diagram of a flexible piezoelectric sensor structure encapsulated by a fish-scale microstructure elastomer provided in an embodiment of the present disclosure;

[0016] Figure 2 A schematic diagram of an optional structural dimension of a flexible piezoelectric sensor encapsulated by a fish-scale microstructure elastomer provided in an embodiment of the present disclosure;

[0017] Figure 3 An optional physical schematic diagram of a flexible piezoelectric sensor encapsulated in a fish-scale microstructure elastomer provided in an embodiment of the present disclosure;

[0018] Figure 4 A schematic diagram of an optional process for preparing a flexible piezoelectric sensor encapsulated with a fish-scale microstructure elastomer provided in an embodiment of the present disclosure;

[0019] Figure 5 Provided for the embodiments of the present disclosure Figure 4 Specific flow chart of step S410;

[0020] Figure 6 Provided for the embodiments of the present disclosure Figure 4 Specific flow chart of step S440;

[0021] Figure 7 An optional schematic diagram of the geometric parameter design of the fish scale microstructure provided in the embodiment of the present disclosure;

[0022] Figure 8 A schematic diagram of an optional design for avoiding lateral interference of the fish scale microstructure unit provided in an embodiment of the present disclosure;

[0023] Figure 9 A schematic diagram of an optional optical morphology of a fish scale microstructure provided in an embodiment of the present disclosure;

[0024] Figure 10 An optional comparison chart of the impact response performance and sensitivity linear fitting of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer provided in the embodiment of the present disclosure;

[0025] Figure 11 An optional performance comparison chart of the response time of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer provided in the embodiment of the present disclosure;

[0026] Figure 12 An optional frequency response performance graph of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer provided in the embodiment of the present disclosure within the range of 5-50 Hz;

[0027] Figure 13 An optional stability performance graph of a flexible piezoelectric sensor encapsulated in a fish-scale microstructure elastomer according to an embodiment of the present disclosure subjected to 3000 cyclic shocks at 6.4 kPa and 5 Hz.

[0028] Figure 14 An optional characteristic signal diagram for monitoring saliva swallowing using a flexible piezoelectric sensor encapsulated by a fish-scale microstructure elastomer according to an embodiment of the present disclosure;

[0029] Figure 15An optional characteristic signal diagram of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer provided by the embodiment of the present disclosure for monitoring the eating and swallowing process;

[0030] Figure 16 An optional characteristic signal diagram of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer provided in the embodiment of the present disclosure for monitoring the drinking and swallowing process;

[0031] Figure 17 An optional characteristic signal diagram of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer provided in the embodiment of the present disclosure for monitoring eating and swallowing disorders and adjustment processes;

[0032] Figure 18 An optional characteristic signal diagram for an application scenario in which a flexible piezoelectric sensor encapsulated in a fish-scale microstructure elastomer provided in an embodiment of the present disclosure monitors the speech production process.

[0033] Reference numerals: elastomer packaging layer 1 , first packaging layer 2 , piezoelectric layer 3 , electrode layer 4 , second packaging layer 5 , graphite conductive zebra paper 6 , flexible circuit cable 7 . DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure and are not intended to limit the present disclosure.

[0035] It should be noted that in various specific embodiments of the present disclosure, when it comes to the need to perform relevant processing based on data related to the characteristics of the target object, such as the target object attribute information or attribute information set, the permission or consent of the target object will be obtained first, and the collection, use and processing of these data will comply with relevant laws, regulations and standards. Among them, the target object can be a user. In addition, when the embodiment of the present disclosure needs to obtain the attribute information of the target object, the separate permission or separate consent of the target object will be obtained through a pop-up window or by jumping to a confirmation page. After clearly obtaining the separate permission or separate consent of the target object, the necessary target object-related data for the normal operation of the embodiment of the present disclosure will be obtained.

[0036] To facilitate understanding of the technical solutions provided by the embodiments of the present disclosure, some key terms used in the embodiments of the present disclosure are explained here:

[0037] Flexible piezoelectric sensors are flexible, bendable devices based on the piezoelectric effect that convert mechanical energy into electrical energy to sense and measure physical quantities. They are widely used in healthcare, smart wearables, and other fields. When a flexible piezoelectric sensor is mechanically deformed by an external force, polarization occurs within the sensor, causing the positive and negative charge centers to separate, generating equal but opposite charges on the surface of the material, forming an electric field.

[0038] Polyimide tape: Made of polyimide resin, it has excellent properties such as high temperature resistance, high tensile strength, good insulation performance, and high chemical stability. It is often used in scenarios such as the electronics field that require high temperature tolerance and electrical insulation performance, such as manufacturing packaging materials for electronic components to protect components from the influence of the external environment.

[0039] Poly-L-lactic acid (PLLA) is a polymer formed by polymerization of poly-L-lactic acid monomers. It is non-toxic, non-irritating, and is a flexible material and biodegradable polymer.

[0040] Ethyl 4-dimethylaminobenzoate (EDB): An organic compound and a commonly used photoinitiator, EDB absorbs ultraviolet light and generates reactive free radicals. It is widely used in photosensitive resins, photoresists, photosensitive inks, and other processes, including photolithography and photocuring. Its photosensitivity makes it an important initiator for photochemical reactions.

[0041] Camphorquinone (also known as hydroquinone and naphthoquinone hydroxide) is a quinone compound derived from the oxidation of camphor. It is commonly used as a photoinitiator in photocuring technology. It absorbs ultraviolet energy and generates reactive free radicals, making it useful in applications such as photocurable resins and photoresists.

[0042] Photocuring: a technology that uses photoinitiators to generate free radicals or cations under ultraviolet light, thereby initiating polymerization reactions in monomers and rapidly curing liquid materials.

[0043] In practical applications, flexible piezoelectric sensors are an important auxiliary tool in the fields of health monitoring and human physiological feature identification. These application scenarios place higher demands on the mechanical performance and sensitivity of flexible piezoelectric sensors. Currently, incorporating microstructure design into flexible piezoelectric sensors has been proven to be an effective strategy for improving mechanical performance and sensitivity. Flexible piezoelectric sensors mainly include an encapsulation layer, a pressure-sensitive layer, and an electrode layer. The microstructure is prepared as the encapsulation layer using a template method. The pressure-sensitive layer is usually enhanced by incorporating high-dielectric constant materials into the pressure-sensitive material to improve response and sensitivity. The electrode layer usually uses metallic conductive materials to collect and transmit the generated charge. Finally, a planar or homogeneous structure method is used for encapsulation. However, when subjected to complex stress, the planar or homogeneous structure encapsulation method is prone to material fatigue or interface delamination due to local stress concentration, which reduces signal stability. The pressure-sensitive layer incorporating high-dielectric constant materials is expensive and complex to prepare. The use of metallic conductive materials can easily lead to rigidification of the flexible piezoelectric sensor, limiting its performance and thus affecting its sensitivity and response speed.

[0044] Based on this, an embodiment of the present disclosure provides a flexible piezoelectric sensor encapsulated in an elastomer with a fish scale microstructure. The stress distribution effect of the elastomer encapsulation layer is optimized through the fish scale microstructure, so that the composite encapsulation structure of the first encapsulation layer and the elastomer encapsulation layer can guide the stress to concentrate in a specific area, enhance local strain capacity and reduce energy dissipation, and improve the sensitivity and response speed of the flexible piezoelectric sensor encapsulated in an elastomer with a fish scale microstructure under low pressure or low frequency conditions.

[0045] The flexible piezoelectric sensor encapsulated in a fish-scale microstructure elastomer provided by the embodiments of the present disclosure will be further described below in conjunction with the accompanying drawings.

[0046] Reference Figure 1 , Figure 1 An optional schematic diagram of a flexible piezoelectric sensor structure with a fish-scale microstructure elastomer package provided in an embodiment of the present disclosure. The flexible main structure includes a first packaging layer 2, a piezoelectric layer 3, an electrode layer 4, and a second packaging layer 5. A rectangular notch is opened in the center area of the first packaging layer 2, and the elastomer packaging layer 1 is covered above the rectangular notch. The piezoelectric layer 3 is bridged to the flexible circuit cable 7 via graphite conductive zebra paper 6. The elastomer packaging layer 1 includes a fish-scale microstructure and a substrate (not shown in the figure). The fish-scale microstructure includes a plurality of fish-scale microstructure units, and the plurality of fish-scale microstructure units are arranged in an array.

[0047] Reference Figure 2 , Figure 2 A schematic diagram of an optional structural size of a flexible piezoelectric sensor packaged with a fish scale microstructure elastomer provided in an embodiment of the present disclosure. The size of the flexible main structure is 32×22 mm. 2The size of the flexible main structure is determined by the first packaging layer 2 and the second packaging layer 5. Therefore, the size of the first packaging layer 2 and the second packaging layer 5 is 32×22mm. 2 The size of the elastomer encapsulation layer 1 is 13×13 mm 2 , the size of the piezoelectric layer 3 is 17×13mm 2 , the size of the electrode layer 4 is 12×12 mm 2 The size of the electrode pins of electrode layer 4 is 4×2mm 2 , which is compatible with the pin size of the flexible circuit cable 7. The flexible circuit cable 7 includes two pins, the width and spacing of a single pin are both 1mm, and the overall size of the flexible circuit cable 7 is 35×4mm 2 .

[0048] Reference Figure 3 , Figure 3 This is an optional physical diagram of a flexible piezoelectric sensor encapsulated by a fish scale microstructure elastomer provided in an embodiment of the present disclosure. The scale of the physical diagram is 2 cm. Figure 3 As shown, the fish-scale microstructure of the elastomer encapsulation layer 1 is assembled toward the outside.

[0049] In some embodiments, the fish-scale microstructure unit is an asymmetric three-dimensional structure based on rhombus transformation, and can be a rhombus-shaped structure.

[0050] In some embodiments, the elastomeric encapsulation layer 1 is made of a polymer of 4-hydroxybutyl acrylate and tetrahydrofuran acrylate, the electrode layer 4 is made of metallic silver, the first encapsulation layer 2 and the second encapsulation layer 5 are made of polyimide, and the piezoelectric layer 3 is made of a mixture of dichloromethane and L-polylactic acid. Specifically, the electrode layer 4 is a flexible silver electrode, consisting of two layers; the piezoelectric layer 3 is a piezoelectric film; and the first encapsulation layer 2 and the second encapsulation layer 5 are both polyimide encapsulation layers.

[0051] In addition, the present disclosure also provides a method for preparing a flexible piezoelectric sensor encapsulated by a fish scale microstructure elastomer, referring to Figure 4 , Figure 4 An optional flow chart of a method for preparing a flexible piezoelectric sensor encapsulated with a fish-scale microstructure elastomer provided in an embodiment of the present disclosure may specifically include but not be limited to the following steps S410 to S440:

[0052] Step S410: preparing a light-curing solution, adding the light-curing solution to a light-curing 3D printing platform, and performing layer-by-layer printing under continuous exposure to ultraviolet light set on the light-curing 3D printing platform to obtain an elastomer encapsulation layer.

[0053] Specifically, a photocurable solution is prepared based on 4-hydroxybutyl acrylic acid and tetrahydrofuran acrylate, and the photocurable solution is added to a photocurable 3D printing platform. Layer by layer printing is performed under continuous exposure to ultraviolet light set on the photocurable 3D printing platform to obtain an elastomer encapsulation layer.

[0054] It should be noted that the elastomer encapsulation layer modeling file has been imported into the light-curing 3D printing platform, and the elastomer encapsulation layer modeling file contains multiple slice files of the fish scale microstructure.

[0055] Step S420: obtaining a low-viscosity polyimide tape and a glass slide, attaching the low-viscosity polyimide tape to the glass slide, and performing laser cutting according to the size of the first encapsulation layer and the size of the second encapsulation layer to obtain the first encapsulation layer and the second encapsulation layer.

[0056] Specifically, the thickness of the low-viscosity polyimide tape is 0.015 mm, the viscosity range is 50 to 150 g, and the size of the first packaging layer is 32×22 mm. 2 , the second packaging layer size is 32×22mm 2 Based on the size of the first packaging layer, the low-viscosity polyimide tape attached to the glass slide was laser cut to obtain a size of 32×22mm. 2 Based on the size of the elastomer packaging layer, a 13×13mm square is cut in the center of the base packaging layer. 2 Then, the polyimide tape attached to the glass slide was laser cut based on the size of the second encapsulation layer to obtain a 32×22 mm 2 The second encapsulation layer.

[0057] Step S430: Prepare a L-polylactic acid mixed solution, drip the L-polylactic acid mixed solution into the piezoelectric layer mold at a uniform speed and let it air dry naturally to obtain a piezoelectric layer, attach the electrode template to the piezoelectric layer, and then perform double-sided sputtering of silver electrodes to obtain piezoelectric layer electrodes.

[0058] Specifically, dichloromethane and L-polylactic acid particles were added to a reagent bottle and placed on a magnetic stirrer for thorough stirring until completely dissolved to obtain a L-polylactic acid mixed solution with a concentration of 2 wt%. Using a casting method, 2 ml of the L-polylactic acid mixed solution was uniformly added dropwise to a 60×20×18 mm 3 The piezoelectric layer mold is naturally air-dried, and the naturally air-dried piezoelectric layer mold is fixed using a customized fixture and high-viscosity polyimide tape. A 4x hot stretching process is completed at a stretching rate of 0.1 mm / s and a temperature of 100°C, and an annealing heat treatment process is performed at a temperature of 140°C for 4 hours to obtain the piezoelectric layer.

[0059] Next, the electrode template was tightly attached to the piezoelectric layer and placed in a magnetron sputtering apparatus for double-sided silver sputtering to form the piezoelectric layer electrode. It should be noted that during this double-sided silver sputtering operation, argon gas was required, the chamber pressure was maintained at 40 mbar, the current was set at 25 mA, and each side was sputtered for 90 seconds.

[0060] It should also be noted that the electrode template can be a metal electrode pattern mask, and the piezoelectric layer electrodes are double-sided electrode pins.

[0061] Step S440: Weld the piezoelectric layer electrode to the flexible circuit cable, attach the welded piezoelectric layer to the first packaging layer and the second packaging layer respectively, cover the elastomer packaging layer onto the rectangular notch of the first packaging layer, and obtain a flexible piezoelectric sensor with fish scale microstructure elastomer packaging.

[0062] It should be noted that the piezoelectric layer electrodes are flush with the flexible circuit wiring and are bridged by graphite conductive zebra paper.

[0063] Reference Figure 5 , Figure 5 Provided for the embodiments of the present disclosure Figure 4 In the specific flow chart of step S410, the preparation method of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer may include but is not limited to steps S510 to S530.

[0064] Step S510: 4-hydroxybutyl acrylic acid and tetrahydrofuran acrylate are mixed in equal proportions to obtain a mixed solution, a first photoinitiator and a second photoinitiator are sequentially added to the mixed solution, and the mixed solution with the first photoinitiator and the second photoinitiator is shaken to obtain a photocurable solution.

[0065] Specifically, equal proportions of 4-hydroxybutyl acrylic acid and tetrahydrofuran acrylate are mixed to obtain a mixed solution, a first photoinitiator and a second photoinitiator with a concentration of 2 wt% are sequentially added to the mixed solution, and the mixed solution with the first photoinitiator and the second photoinitiator added is thoroughly shaken by an adjustable mixer to obtain a photocurable solution, which is then sealed and stored in a light-proof environment.

[0066] It should be noted that the first photoinitiator may be camphorquinone, and the second photoinitiator may be ethyl 4-dimethylaminobenzoate.

[0067] Step S520: obtaining geometric parameters of the elastomer encapsulation layer, modeling the elastomer encapsulation layer based on the geometric parameters of the elastomer encapsulation layer, and obtaining a modeling file of the elastomer encapsulation layer.

[0068] Specifically, the geometric parameters of the elastomer encapsulation layer were obtained, and modeling was performed using 3D drawing software based on the geometric parameters of the elastomer encapsulation layer to obtain the elastomer encapsulation layer model, which includes a base model and a fish scale microstructure model. The actual printing effect of the elastomer encapsulation layer model was simulated using a light-curing 3D printing platform, and the size of the elastomer encapsulation layer model was determined to be 13×13×0.8mm. 3 , that is, the length and width of the elastomer encapsulation layer model are 13 mm, and the height is 0.7 mm, wherein the heights of the base model and the fish scale microstructure model of the elastomer encapsulation layer model are both 0.4 mm.

[0069] Next, the elastomer encapsulation layer model is imported into the slicing software for slicing preparation. The slicing layer parameters are set to 0.2 mm. The elastomer encapsulation layer model is divided into a series of two-dimensional slices according to the slicing layer parameters. Multiple two-dimensional slices are exported as .png format slice files to obtain the elastomer encapsulation layer modeling file.

[0070] Step S530: Add a photocuring solution to the photocuring 3D printing platform into which the elastomer encapsulation layer modeling file is imported, import the elastomer encapsulation layer modeling file into the photocuring 3D printing platform, and perform layer-by-layer printing under continuous exposure to ultraviolet light set by the photocuring 3D printing platform to obtain the elastomer encapsulation layer.

[0071] Specifically, the light-curing 3D printing platform includes a solution pool, a specific code program, and a light-curing 3D printer. Use a plastic dropper to draw 1 ml of light-curing solution and add it to the solution pool of the light-curing 3D printing platform. Import the elastomer encapsulation layer modeling file into the specific code program of the light-curing 3D printing platform for identification and processing. After completing the bottom search work and setting the printing parameters in the light-curing 3D printing platform, run the light-curing 3D printer to start preparing the fish scale microstructure. During the printing process, the fish scale microstructure is printed layer by layer under continuous exposure to ultraviolet light to obtain a size of 13×13×0.4mm. 3 Finally, the printed elastomer encapsulation layer is post-processed to complete the preparation of the elastomer encapsulation layer.

[0072] It should be noted that the settings of the printing parameters include: the power density parameter is set to 10.68mW / cm 2 , the single layer curing time is 60s, the printing layer thickness is 0.2mm, the initial lifting distance is 0.1mm, the step lifting distance is 0.1mm, and the wavelength of the ultraviolet light is 405nm.

[0073] Reference Figure 6 , Figure 6 Provided for the embodiments of the present disclosure Figure 4In the specific flow chart of step S440, the preparation method of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer may include but is not limited to steps S610 to S630.

[0074] Step S610: After aligning the piezoelectric layer electrodes with the flexible circuit cables, graphite conductive zebra paper is used for bridging, and the bridging portions are subjected to hot pressing welding to obtain a pressure-sensitive layer.

[0075] Specifically, after aligning the piezoelectric layer electrode with the flexible circuit cable, graphite conductive zebra paper is used to bridge the piezoelectric layer electrode and the flexible circuit cable, and the bridge portion is hot-pressed and welded using a pulse hot press. During the hot-press welding process, the hot press moves to the bridge portion and heats up to 120°C, then preheats for 5 seconds. A heat-saturating rubber sheet is then covered over the bridge portion. The welding switch is then pressed, causing the hot press to contact the bridge portion and increase pressure until the temperature rises to 140°C. This process is maintained for 11 seconds.

[0076] Next, the electrode layer is attached to the piezoelectric layer, and graphite conductive zebra paper is used to bridge the electrode pins of the flexible silver electrode in the electrode layer with the flexible circuit cable. The bridged area is hot-pressed and welded using a pulse hot press to make the flexible circuit cable flush with the piezoelectric layer and sandwiched between the upper and lower graphite conductive zebra papers to obtain a pressure-sensitive layer.

[0077] It should also be noted that the flexible circuit cable includes two pins, such as Figure 1 As shown, during the hot pressing welding operation, the piezoelectric layer electrode is bridged with the pin on the right side of the flexible circuit cable through the graphite conductive zebra paper; the electrode layer includes two flexible silver electrodes, and the electrode pins of the two flexible silver electrodes are bridged with the two pins of the flexible circuit cable respectively through the graphite conductive zebra paper.

[0078] Step S620: attaching the pressure-sensitive layer to the second packaging layer to complete the lower packaging, and attaching the other side of the pressure-sensitive layer to the first packaging layer to complete the upper packaging, so that the pressure-sensitive layer is located between the first packaging layer and the second packaging layer.

[0079] Specifically, the electrode layer side of the pressure-sensitive layer is flatly attached to the second packaging layer to complete the lower layer packaging, and the first packaging layer is aligned with the piezoelectric layer electrode and the outer edge of the second packaging layer and then attached to the piezoelectric layer side of the pressure-sensitive layer, so that the pressure-sensitive layer is located between the first packaging layer and the second packaging layer.

[0080] Step S630: Covering the rectangular notch of the first packaging layer with an elastomer packaging layer to obtain a flexible piezoelectric sensor with fish-scale microstructure elastomer packaging, wherein the second structure corner faces the flexible circuit wiring side.

[0081] Specifically, with the help of the self-adhesiveness of the elastomer packaging layer, the second structural corner of the fish-scale microstructure unit in the fish-scale microstructure layer of the elastomer packaging layer is directed toward the side of the flexible circuit wiring, and then the elastomer packaging layer is covered on the rectangular notch of the first packaging layer after alignment with the outer contour edge of the rectangular notch as a reference to achieve complete sealing, thereby obtaining a flexible piezoelectric sensor with fish-scale microstructure elastomer packaging.

[0082] In some embodiments, the geometric parameters of the elastomer encapsulation layer include the size of the elastomer encapsulation layer and the geometric parameters of the fish scale microstructure. The geometric parameters of the fish scale microstructure are used to determine the geometric shape of the fish scale microstructure unit and the geometric layout of multiple fish scale microstructure units in the fish scale microstructure. The elastomer encapsulation layer is modeled based on the size of the elastomer encapsulation layer and the geometric parameters of the fish scale microstructure.

[0083] In some embodiments, the geometric parameters of the fish scale microstructure include a first structural angle, a second structural angle, a lateral distance, and a longitudinal distance; the first structural angle is the structural angle of the diamond plane pattern, and any vertex angle of the diamond plane pattern is transformed on the central axis where the vertex is located to obtain the second structural angle, wherein the first structural angle is greater than the second structural angle; the longitudinal distance is twice the lateral distance.

[0084] Specifically, the geometric parameters of the fish scale microstructure include a first structural angle, a second structural angle, a main side length, a transverse distance, a longitudinal distance, and an initial side spacing. When determining the geometric parameters of the fish scale microstructure unit, the first structural angle is the structural angle of the diamond plane pattern, and any vertex of the diamond plane pattern is transformed on the central axis where the vertex is located to obtain the second structural angle. The side length connected to the transformed vertex is used as the main side length, and the geometric parameters of the fish scale microstructure unit are determined based on the first structural angle, the second structural angle, and the main side length. Then, the geometric layout of multiple fish scale microstructure units in the fish scale microstructure is determined based on the transverse line distance, the lateral distance, and the initial side spacing. Refer to Figure 7 , Figure 7 An optional schematic diagram of the geometric parameter design of the fish scale microstructure provided by the embodiment of the present disclosure, θ1 is the first structural angle, θ2 is the second structural angle, l is the main side length, x is the horizontal distance, y is the longitudinal distance, and d0 is the initial side spacing. Figure 7 Taking the fish scale microstructure unit in the dotted area of the middle circle as an example, the pattern composed of vertex angles A, B, C and D is a diamond, ∠ADB is the first structural angle, and vertex angle D is stretched along the central axis where vertex angles B and D are located to vertex angle D′, and ∠AD′B is the second structural angle.

[0085] Furthermore, in order to prevent the adjacent fish scale microstructure units from interfering with each other when deformed under the action of external vertical pressure, causing different degrees of adhesion or even irreversible adhesion, which affects the performance of the fish scale microstructure, reference is made to Figure 8 , Figure 8 A schematic diagram of an optional design for avoiding lateral interference of a fish scale microstructure unit provided in an embodiment of the present disclosure, wherein A is the centroid of the fish scale microstructure unit, A′ is the symmetric point of the centroid A, b is the distance from the symmetric point A′ to point O before deformation (i.e., line segment A′O), Δb is the lateral deformation value after deformation (i.e., line segment OP), d n is the maximum lateral spacing. Taking the centroid A of the fish scale microstructure unit as the reference origin, when the fish scale microstructure is subjected to external force and undergoes lateral deformation, it is assumed that the deformation at each location is uniform, and the overall geometric structure of the fish scale microstructure unit remains unchanged during the deformation process, and only a certain displacement is generated, so the first structural angle and the second structural angle remain unchanged. However, the fish scale microstructure unit will deform in the thickness direction. When the thickness of the fish scale microstructure unit decreases, the longitudinal distance also decreases. Therefore, it will extend in the lateral direction, resulting in a lateral deformation value Δb. The lateral strain ε of the fish scale microstructure unit is x According to the formula ε x =Δb / b, the Poisson's ratio μ of the elastomer encapsulation layer can be calculated using the formula μ=ε x / ε y Get, ε y is the longitudinal strain of the fish scale microstructure unit. According to the transverse strain formula, Poisson's ratio formula and trigonometric function relationship, the initial side spacing d is obtained. o Maximum side distance d n The following relationship should be satisfied.

[0086] d0>d n =Δb / cosθ2=με y b / cosθ2

[0087] According to the above process, the geometric parameters of the fish scale microstructure can be determined: the first structural angle is 60°, the second structural angle is 45°, the main side length is 0.6mm, the horizontal spacing is 0.2mm, and the vertical spacing is 0.4mm. Figure 9 , Figure 9 Schematic diagram of an optional optical topography of a fish scale microstructure provided in an embodiment of the present disclosure, where the scale of each optical topography diagram is 500 μm. At 90° and 45° viewing angles and at different magnifications, the geometric features of the fish scale microstructure units and arrays of multiple fish scale microstructure units are clearly defined, meeting the geometric parameters and size requirements of the fish scale microstructure.

[0088] A series of comparative tests were also conducted on the flexible piezoelectric sensor encapsulated in the fish-scale microstructure elastomer provided in the embodiment of the present disclosure. The performance of the flexible piezoelectric sensor encapsulated in the fish-scale microstructure elastomer provided in the embodiment of the present disclosure will be further explained below in conjunction with the accompanying drawings.

[0089] Comparative test of impact performance of flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer: The flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer is connected to the self-built shock response test system, and the shock response and sensitivity tests are carried out within the low pressure range of 0-20kPa. The performance comparison can be referred to the PLLA sensor encapsulated by planar structure elastomer and the PLLA sensor without elastomer encapsulation. Figure 10 , Figure 10 An optional comparison chart of the impact response performance and sensitivity linear fitting of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer provided in the embodiment of the present disclosure, according to Figure 10 It can be seen that the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer prepared in the embodiment of the present disclosure has better shock response performance and sensitivity, and the sensitivity is as high as 24.35mv·kPa -1 .

[0090] Comparative test of the response time performance of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer: The PLLA sensor encapsulated by the planar structure elastomer and the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer provided by the embodiment of the present disclosure were regularly struck under an impact force of about 20kPa. The performance comparison can be referred to Figure 11 , Figure 11 An optional performance comparison chart of the response time of the flexible piezoelectric sensor packaged with the fish scale microstructure elastomer provided in the embodiment of the present disclosure, according to Figure 11 It can be seen that the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer prepared in the embodiment of the present disclosure has a faster response time.

[0091] Frequency response performance test of flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer: The flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer provided by the embodiment of the present disclosure is connected to the electronic dynamic and static load test system, and tested in the range of 5-50Hz under the impact load condition of 6.4kPa. The performance obtained can be referred to Figure 12 , Figure 12 An optional frequency response performance diagram of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer provided in the embodiment of the present disclosure in the range of 5-50Hz, according to Figure 12 It can be seen that the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer prepared in the embodiment of the present disclosure shows better response characteristics in a low-frequency environment.

[0092] Stability performance test of flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer: The flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer provided by the embodiment of the present disclosure is connected to the electronic dynamic and static load test system, and 3000 cycles of impact test are carried out under the conditions of 6.4kPa impact load and 5Hz low frequency. The performance obtained can be referred to Figure 13, Figure 13 An optional stability performance diagram of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer provided in the embodiment of the present disclosure under 6.4kPa, 5Hz conditions for 3000 cycles of impact, according to Figure 13 It can be seen that the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer prepared in the embodiment of the present disclosure shows good stability in a long-term low-frequency working environment.

[0093] Swallowing action detection application test of flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer: The flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer provided by the embodiment of the present disclosure is attached to the human throat and connected to the swallowing signal acquisition system, and the signal is collected during the saliva swallowing process. The obtained signal characteristics can be referred to Figure 14 , Figure 14 An optional characteristic signal diagram for monitoring the swallowing process of saliva using a flexible piezoelectric sensor encapsulated by a fish scale microstructure elastomer according to an embodiment of the present disclosure. Figure 14 It can be seen that the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer prepared in the embodiment of the present disclosure can accurately capture the characteristics of swallowing movements and is consistent with the three-stage swallowing theory.

[0094] Application test of monitoring swallowing process of flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer: The flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer provided by the embodiment of the present disclosure is attached to the human throat and connected to the swallowing signal acquisition system, and the signal is collected for the swallowing process involved in eating. The obtained signal characteristics can be referred to Figure 15 , Figure 15 An optional characteristic signal diagram for monitoring the swallowing process of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer provided in the embodiment of the present disclosure. Figure 15 It can be seen that the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer prepared in the embodiment of the present disclosure can accurately distinguish and capture the characteristics of chewing and swallowing movements, and can accurately quantify the subtle changes in the force-electricity conversion relationship in the continuous process.

[0095] Application test of monitoring drinking and swallowing process of flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer: The flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer provided by the embodiment of the present disclosure is attached to the human throat and connected to the swallowing signal acquisition system, and the signal is collected for the swallowing process involved in drinking water. The obtained signal characteristics can be referred to Figure 16 , Figure 16 An optional characteristic signal diagram for monitoring the drinking and swallowing process of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer provided in the embodiment of the present disclosure. Figure 16It can be seen that the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer prepared in the embodiment of the present disclosure can accurately capture the swallowing action characteristics when drinking water, and can accurately quantify the subtle changes in the force-electricity conversion relationship in the continuous process.

[0096] Application test of monitoring swallowing difficulty adjustment process of flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer: The flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer provided by the embodiment of the present disclosure is attached to the human throat and connected to the swallowing signal acquisition system, and the signal is collected for the swallowing difficulty and adjustment process during eating. The obtained signal characteristics can be referred to Figure 17 , Figure 17 An optional characteristic signal diagram for the application scenario of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer provided in the embodiment of the present disclosure for monitoring eating and swallowing disorders and adjustment processes, according to Figure 17 It can be seen that the flexible piezoelectric sensor encapsulated by the fish-scale microstructure elastomer prepared in the embodiment of the present disclosure accurately captures the dynamic adjustment change characteristics in the process.

[0097] Speech recognition detection application test of flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer: The flexible piezoelectric sensor encapsulated by fish scale microstructure elastomer provided by the embodiment of the present disclosure is attached to the human throat and connected to the swallowing signal acquisition system. Signals are collected twice for the pronunciation process of "east, west, south, and north". The pronunciations of "west" and "north" are emphasized successively. The signal characteristics obtained can be referred to Figure 18 , Figure 18 An optional characteristic signal diagram for the application scenario of the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer provided in the embodiment of the present disclosure for monitoring the speech sound process, according to Figure 18 It can be seen that the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer prepared in the embodiment of the present disclosure can accurately capture the signal characteristics of different syllables, and the differences in signal characteristics of the same syllable with different volumes can also be significantly presented.

[0098] In summary, the flexible piezoelectric sensor with fish scale microstructure elastomer package and its preparation method provided by the embodiment of the present disclosure, by utilizing the elastomer packaging layer based on the fish scale microstructure, can improve the force transmission path along the thickness direction when subjected to a small pressure phenotype, guide the stress to concentrate in a specific area, enhance the local strain, and thus accelerate the charge generation rate of the piezoelectric material to mechanical stimulation. At the same time, the fish scale microstructure contains a plurality of fish scale microstructure units, and the fish scale microstructure is assembled toward the outside. The multi-point contact mechanism of its surface with the external force and the localized deformation mechanism weaken the negative effect of the overall thickness on the response speed, suppress the overall resonance effect of the packaging layer under low-frequency vibration, avoid energy retention, and enable the flexible sensor to quickly return to its initial state, thereby improving the sensitivity and response speed of the flexible sensor under low pressure and low frequency conditions. In addition, the composite packaging structure of the fish-scale microstructure elastomer packaging layer and the polyimide packaging layer (first packaging layer) can reduce energy dissipation while ensuring the reliability of the packaging seal, and the assembly scheme with one side of the fish-scale microstructure facing outward can better adapt to the complex surface of human skin. The array arrangement of the fish-scale microstructure units enables the flexible sensor to form microchannels when attached to the skin to help perspiration, effectively improving wearing comfort.

[0099] The terms "first," "second," "third," "fourth," and the like (if any) in the specification of the present disclosure and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate to describe embodiments of the present disclosure, e.g., capable of being implemented in orders other than those illustrated or described herein. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions, e.g., a process, method, system, product, or apparatus comprising a series of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0100] It should be understood that in the present disclosure, "at least one (item)" refers to one or more, and "plurality" refers to two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0101] It should be understood that in the description of the embodiments of the present disclosure, the meaning of multiple (or multiple items) is more than two, greater than, less than, exceed, etc. are understood to exclude the number itself, and above, below, within, etc. are understood to include the number itself.

[0102] In the several embodiments provided in the present disclosure, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0103] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0104] In addition, the functional units in the various embodiments of the present disclosure may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0105] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present disclosure is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the various embodiments of the present disclosure. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program code.

[0106] It should also be understood that the various implementations provided in the embodiments of the present disclosure can be combined arbitrarily to achieve different technical effects.

[0107] The above is a specific description of the preferred implementation of the present disclosure, but the present disclosure is not limited to the above implementation. Technical personnel familiar with the art can also make various equivalent modifications or substitutions under the shared conditions that do not violate the spirit of the present disclosure. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present disclosure.

Claims

1. A flexible piezoelectric sensor encapsulated by a fish scale microstructure elastomer, characterized in that: include: A flexible main body structure includes a first packaging layer, a piezoelectric layer, an electrode layer and a second packaging layer. A rectangular notch is opened in the central area of the first packaging layer, and an elastomer packaging layer is covered above the rectangular notch. The elastomer packaging layer includes a substrate and a fish-scale microstructure. The fish-scale microstructure includes a plurality of fish-scale microstructure units, and the plurality of fish-scale microstructure units are arranged in an array.

2. The flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer according to claim 1, characterized in that: The fish scale microstructure unit is an asymmetric three-dimensional structure based on rhombus transformation.

3. The flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer according to claim 1, characterized in that: The material of the elastomer packaging layer is a polymer of 4-hydroxybutyl acrylic acid and tetrahydrofuran acrylate, the material of the electrode layer is metallic silver, the material of the first packaging layer and the second packaging layer is polyimide, and the material of the piezoelectric layer is a mixture of dichloromethane and L-polylactic acid.

4. A method for preparing a flexible piezoelectric sensor encapsulated by a fish scale microstructure elastomer, applied to the flexible piezoelectric sensor encapsulated by a fish scale microstructure elastomer according to any one of claims 1 to 3, characterized in that: include: preparing a light-curing solution, adding the light-curing solution to a light-curing 3D printing platform, and performing layer-by-layer printing under continuous exposure to ultraviolet light set on the light-curing 3D printing platform to obtain the elastomer encapsulation layer; Obtaining a low-viscosity polyimide tape and a glass slide, attaching the low-viscosity polyimide tape to the glass slide, and performing laser cutting according to the size of the first encapsulation layer and the size of the second encapsulation layer to obtain the first encapsulation layer and the second encapsulation layer; A L-polylactic acid mixed solution is prepared, and the L-polylactic acid mixed solution is uniformly dripped into a piezoelectric layer mold for natural air drying to obtain the piezoelectric layer, and an electrode template is attached to the piezoelectric layer and then a double-sided silver electrode operation is performed to obtain a piezoelectric layer electrode; The piezoelectric layer electrode is welded to the flexible circuit cable, the welded piezoelectric layer is attached to the first packaging layer and the second packaging layer respectively, and the elastomer packaging layer is covered on the rectangular notch of the first packaging layer to obtain the flexible piezoelectric sensor with fish scale microstructure elastomer packaging.

5. The method for preparing the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer according to claim 4, characterized in that: Mixing equal proportions of 4-hydroxybutyl acrylic acid and tetrahydrofuran acrylate to obtain a mixed solution, sequentially adding a first photoinitiator and a second photoinitiator to the mixed solution, and shaking the mixed solution containing the first photoinitiator and the second photoinitiator to obtain the photocurable solution; obtaining geometric parameters of the elastomer encapsulation layer, and modeling the elastomer encapsulation layer based on the geometric parameters of the elastomer encapsulation layer to obtain a modeling file of the elastomer encapsulation layer; The photocurable solution is added to the photocurable 3D printing platform, the elastomer encapsulation layer modeling file is imported into the photocurable 3D printing platform, and layer-by-layer printing is performed under continuous exposure to ultraviolet light set on the photocurable 3D printing platform to obtain the elastomer encapsulation layer.

6. The method for preparing the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer according to claim 5, characterized in that: The geometric parameters of the elastomer encapsulation layer include the size of the elastomer encapsulation layer and the geometric parameters of the fish scale microstructure, and the geometric parameters of the fish scale microstructure are used to determine the geometric shape of the fish scale microstructure unit and the geometric layout of multiple fish scale microstructure units in the fish scale microstructure; The elastomer encapsulation layer is modeled based on the size of the elastomer encapsulation layer and the geometric parameters of the fish scale microstructure.

7. The method for preparing the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer according to claim 6, characterized in that: The geometric parameters of the fish scale microstructure include a first structural angle, a second structural angle, a transverse distance and a longitudinal distance; the first structural angle is the structural angle of the diamond plane pattern, and any vertex angle of the diamond plane pattern is transformed on the central axis where the vertex is located to obtain the second structural angle; wherein the first structural angle is greater than the second structural angle, and the longitudinal distance is twice the transverse distance.

8. The method for preparing the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer according to claim 4, characterized in that: The polyimide tape attached to the glass slide is laser cut based on the size of the first packaging layer to obtain a basic packaging layer, and laser cutting is performed again in the central area of the basic packaging layer based on the size of the elastomer packaging layer to obtain the first packaging layer with the rectangular notch.

9. The method for preparing the flexible piezoelectric sensor encapsulated by the fish scale microstructure elastomer according to claim 4, characterized in that: After aligning the piezoelectric layer electrode with the flexible circuit cable, use graphite conductive zebra paper to perform bridging, and perform hot pressure welding on the bridging part to obtain a pressure-sensitive layer; attach the pressure-sensitive layer to the second packaging layer to complete the lower layer packaging, and attach the other side of the pressure-sensitive layer to the first packaging layer to complete the upper layer packaging, so that the pressure-sensitive layer is located between the first packaging layer and the second packaging layer; cover the elastomer packaging layer onto the rectangular notch of the first packaging layer to obtain the fish scale microstructure elastomer-encapsulated flexible piezoelectric sensor, wherein the second structure angle faces the side of the flexible circuit cable.

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