A nanogenerator, a preparation method and application thereof

Abstract

The application relates to a nanogenerator, a preparation method and application, the nanogenerator comprising a piezoelectric layer, a friction layer and an encapsulation layer, the piezoelectric layer comprising a polyvinylidene fluoride piezoelectric film, a silver electrode and a polyimide film; the friction layer is arranged on one side of the piezoelectric layer and generates charge transfer with the piezoelectric layer, and the friction layer comprises a polytetrafluoroethylene film after surface activation by plasma etching; and the encapsulation layer covers the outer surfaces of the piezoelectric layer and the friction layer respectively.The advantages are that stable direct current output is realized by coupling of triboelectric effect and piezoelectric effect, so that renewable electric energy can be provided for various electronic devices, the problems of limited storage capacity and environmental pollution of existing external power sources are overcome, the preparation method is simple and convenient for batch production, the performance is excellent and fatigue resistant, mechanical damage under the action of external force or vibration is not prone to occur, so that the working life is derived, and the biocompatibility is good, so that the nanogenerator can be implanted as an implant material.

Description

Technical Field

[0001] This invention relates to the field of micro-nano energy power generation technology, and in particular to a nanogenerator, its preparation method, and its application. Background Technology

[0002] Triboelectricity is a common phenomenon in nature. It occurs when objects rub against each other, causing one object to become positively charged and the other negatively charged. Examples include static electricity generated when putting on or taking off clothes, or when combing hair. However, due to a lack of equipment, instruments, or apparatus for collecting and utilizing triboelectricity, it is often wasted.

[0003] To address these issues, researchers have developed a triboelectric generator that generates electricity through friction, converting minute amounts of mechanical energy into electrical energy. Common triboelectric generators are transparent, flexible models that utilize flexible polymer materials.

[0004] However, this type of triboelectric generator has some drawbacks, such as harsh operating conditions, requiring operation under uniform mechanical force / vibration; it is prone to mechanical damage if operated under non-uniform mechanical force / vibration for a long time; it has poor fatigue resistance and cannot be used for a long time; and it has poor biocompatibility, making it difficult to use as an implant material.

[0005] With the development of technology, electronic products such as smartphones, smartwatches, and smart bracelets are showing a trend towards miniaturization, multifunctionality, portability, and wearability. Due to the diverse application scenarios, high demand, and low energy consumption of these products, reliance on traditional battery power supply methods limits their further application. Therefore, there is an urgent need to develop new power sources that can continuously power small electronic devices while addressing the environmental pollution, limited battery life, and potential health hazards associated with traditional power supply methods.

[0006] Nanogenerators, as an emerging power generation technology, have gained increasing attention and application due to their green and sustainable conversion of mechanical energy into electrical energy. They are mainly divided into triboelectric nanogenerators and piezoelectric nanogenerators. The mechanism of triboelectric nanogenerators originates from the triboelectric effect, where charge transfer and a potential difference occur when two materials with different triboelectric polarities come into contact. Driven by this potential difference, the charge flows back and forth between the two electrodes, thus forming an electric current. Piezoelectric nanogenerators are manufactured using the principle of generating current by bending and compressing special nanomaterials with piezoelectric properties.

[0007] Currently, most nanogenerators are fabricated using a single power generation method, which results in low power generation efficiency, poor stability, and poor fatigue resistance. Furthermore, they lack good biocompatibility, limiting their applications.

[0008] Currently, no effective solutions have been proposed for the problems of low power generation efficiency, poor stability, poor fatigue resistance, and poor biocompatibility in related technologies. Summary of the Invention

[0009] The purpose of this application is to address the shortcomings of existing technologies by providing a nanogenerator, its preparation method, and its application, thereby at least solving the problems of low power generation efficiency, poor stability, poor fatigue resistance, and poor biocompatibility in related technologies.

[0010] To achieve the above objectives, the technical solution adopted in this application is as follows: In a first aspect, the present invention provides a nanogenerator, comprising: A piezoelectric layer, comprising a polyvinylidene fluoride piezoelectric film, a silver electrode, and a polyimide film; A friction layer is disposed on one side of the piezoelectric layer and generates charge transfer with the piezoelectric layer. The friction layer includes a polytetrafluoroethylene film activated by plasma etching. An encapsulation layer covers the outer surface of the piezoelectric layer and the outer surface of the friction layer, and the encapsulation layer includes a Teflon film and a polydimethylsiloxane film.

[0011] In some embodiments, the piezoelectric layer includes: Polyvinylidene fluoride piezoelectric film; A silver electrode is disposed on the surface of the polyvinylidene fluoride piezoelectric film, forming a silver / polyvinylidene fluoride piezoelectric film / silver structure; A polyimide film is disposed covering one side surface of the polyvinylidene fluoride piezoelectric film, forming a silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure.

[0012] In some embodiments, the friction layer comprises: A polytetrafluoroethylene (PTFE) film, wherein the PTFE film is disposed on one side surface of the piezoelectric layer, and the PTFE film is activated by plasma etching. An aluminum electrode is disposed on the outer surface of the polytetrafluoroethylene film, forming a polytetrafluoroethylene film / aluminum electrode structure; A polyimide film is disposed covering the outer surface of the aluminum electrode, forming a polytetrafluoroethylene film / aluminum electrode / polyimide film structure.

[0013] In some embodiments, the encapsulation layer includes: A Teflon film is provided to cover the outer surface of the piezoelectric layer and the outer surface of the friction layer, forming a Teflon film / piezoelectric layer / friction layer / Teflon film structure; A polydimethylsiloxane film is provided to cover the outer surface of the Teflon film, forming a polydimethylsiloxane / Teflon film / piezoelectric layer / friction layer / Teflon film / polydimethylsiloxane structure.

[0014] In some of these embodiments, the thickness of the silver / polyvinylidene fluoride piezoelectric film / silver structure is 100 μm.

[0015] In some of these embodiments, the polyimide film in the piezoelectric layer has a thickness of 100 μm.

[0016] In some of these embodiments, it also includes: An insulating layer is disposed at both ends of the friction layer and connected to the friction layer and the piezoelectric layer respectively. The insulating layer includes an acrylic film.

[0017] In some embodiments, there are multiple friction layers, and an insulating layer is disposed between two adjacent friction layers.

[0018] In some embodiments, the insulating layer comprises: Two acrylic films are symmetrically disposed at both ends of the friction layer, and each acrylic film is connected to the friction layer and the piezoelectric layer respectively.

[0019] In some of these embodiments, the acrylic film has a thickness of 0.8 mm.

[0020] Secondly, a method for preparing a nanogenerator is provided, comprising: (Preparation of piezoelectric layer) A silver electrode is sprayed onto the outer surface of a polyvinylidene fluoride piezoelectric film to form a silver / polyvinylidene fluoride piezoelectric film / silver structure. The silver / polyvinylidene fluoride piezoelectric film / silver structure is combined with a polyimide film to form a silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure. (Preparation of the friction layer) Plasma etching was used to activate the surface of a polytetrafluoroethylene (PTFE) film to obtain a PTFE film with a nanostructure. The polytetrafluoroethylene film, aluminum electrode, and polyimide film are combined to form a polytetrafluoroethylene film / aluminum electrode / polyimide film structure. (Packaging) The silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure is combined with the polytetrafluoroethylene film / aluminum electrode / polyimide film structure to form a polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure. The polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure is combined with a Teflon film to form a Teflon film / polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film / Teflon film structure. The Teflon film / polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film / Teflon film structure is combined with a polydimethylsiloxane film to form a polydimethylsiloxane / Teflon film / polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film / Teflon film / polydimethylsiloxane structure, thereby obtaining a nanogenerator.

[0021] In some of these embodiments, the thickness of the silver / polyvinylidene fluoride piezoelectric film / silver structure is 100 μm.

[0022] In some of these embodiments, the polyimide film has a thickness of 100 μm during the fabrication of the piezoelectric layer.

[0023] In some of these embodiments, it also includes: (Preparation of insulating layer) An acrylic film is disposed at both ends of the polytetrafluoroethylene film / aluminum electrode / polyimide film structure to form an acrylic film / polytetrafluoroethylene film / aluminum electrode / polyimide film structure. The packaging also includes: The silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure is combined with the acrylic film / polytetrafluoroethylene film / aluminum electrode / polyimide film structure to form a polyimide film / aluminum electrode / polytetrafluoroethylene film / acrylic film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure.

[0024] In some of these embodiments, the acrylic film has a thickness of 0.8 mm.

[0025] Thirdly, the application of a nanogenerator as described in the first aspect or a nanogenerator obtained by the preparation method described in the second aspect in the preparation of bioimplant materials.

[0026] Compared to related technologies, the nanogenerator, preparation method, and application provided in this application embodiment achieve stable DC current output by utilizing the coupling of triboelectric and piezoelectric effects, thereby providing renewable electrical energy for various electronic devices. This overcomes the problems of limited storage capacity and environmental pollution associated with existing external power supplies. The preparation method is simple and facilitates mass production. It exhibits excellent performance and fatigue resistance, and is not prone to mechanical damage under external forces or vibrations, thus extending its working life. It also has good biocompatibility and can be used as an implant material. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the structure of a nanogenerator according to an embodiment of the present invention (I); Figure 2 This is a schematic diagram of the structure of the piezoelectric layer according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the friction layer according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the encapsulation layer according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the insulating layer according to an embodiment of the present invention; Figure 6 This is a schematic diagram (II) of the structure of a nanogenerator according to an embodiment of the present invention. Figure 7 This is a schematic diagram of a method for preparing a nanogenerator according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the packaging layer structure of a nanogenerator according to an embodiment of the present invention; Figure 9 This is a schematic diagram of corona discharge in plasma etching according to an embodiment of the present invention; Figure 10 This is a scanning electron microscope image of a polytetrafluoroethylene film after surface activation by plasma etching according to an embodiment of the present invention; Figure 11 This is a schematic diagram illustrating the piezoelectric or triboelectric power supply principle of a nanogenerator according to an embodiment of the present invention; Figure 12 This is a schematic diagram of a nanogenerator according to an embodiment of the present invention performing simple piezoelectric or triboelectric and composite HTP output electrical signals; Figure 13 This is a schematic diagram of the external electrical output performance test of the nanogenerator according to an embodiment of the present invention; Figures 14a-14b This is a schematic diagram of a 5000-cycle fatigue resistance test of a nanogenerator according to an embodiment of the present invention; Figure 15 This is a schematic diagram of the airtightness test of a nanogenerator according to an embodiment of the present invention; Figure 16 This is a schematic diagram of the output electrical signal of the nanogenerator under the action of a hand tap, according to an embodiment of the present invention; Figure 17This is a schematic diagram of the output electrical signal of the nanogenerator under the action of elbow joint movement according to an embodiment of the present invention; Figure 18 This is a schematic diagram of the output electrical signal of the nanogenerator under the action of knee joint movement according to an embodiment of the present invention; Figure 19 This is a schematic diagram of the output electrical signal of a nanogenerator after implantation in a knee joint according to an embodiment of the present invention; Figure 20 This is a schematic diagram of the biocompatibility test of a nanogenerator according to an embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0029] Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0030] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0031] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms “a,” “an,” “an,” “the,” and similar words used in this application do not indicate quantity limitation and may indicate singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms “connected,” “linked,” “coupled,” and similar words used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Multiple” used in this application refers to two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following objects are in an "or" relationship. The terms "first," "second," and "third" used in this application are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0032] Example 1 This embodiment relates to the nanogenerator, its preparation method, and its application according to the present invention.

[0033] like Figure 1 As shown, a nanogenerator (hereinafter referred to as HTP-NG) includes a piezoelectric layer, a tribological layer, and an encapsulation layer. The tribological layer is disposed on one side of the piezoelectric layer and generates charge transfer with the piezoelectric layer; the encapsulation layer covers the outer surface of both the piezoelectric layer and the outer surface of the tribological layer.

[0034] like Figure 2 As shown, the piezoelectric layer includes a polyvinylidene fluoride piezoelectric film (PVDF film), a silver electrode (Ag), and a polyimide film (Kapton film).

[0035] Specifically, a silver electrode is disposed on the surface of a polyvinylidene fluoride piezoelectric film, forming a silver / polyvinylidene fluoride piezoelectric film / silver structure (Ag / PVDF / Ag film); a polyimide film is disposed on one side of the surface of the polyvinylidene fluoride piezoelectric film, forming a silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure (Ag / PVDF / Ag / Kapton film).

[0036] In this design, a silver electrode serves as the conductive layer, and a polyimide film serves as the substrate.

[0037] In some of these embodiments, the thickness of the Ag / PVDF / Ag film is 110 μm.

[0038] In some of these embodiments, the PVDF film has dimensions of 0.5 cm × 2 cm to 2 cm × 8 cm.

[0039] In some of these embodiments, the thickness of the Kapton film is 100 μm.

[0040] like Figure 3 As shown, the friction layer comprises a PTFE film with nanostructure after plasma etching and surface activation. Additionally, the friction layer also includes an aluminum electrode (Al) and a polyimide film (Kapton film).

[0041] In this process, the aluminum electrode serves as the conductive layer.

[0042] Specifically, an aluminum electrode is disposed on the outer surface of a polytetrafluoroethylene (PTFE) film, forming a PTFE / Al film structure; a polyimide film is disposed on the outer surface of the aluminum electrode, forming a PTFE / Al / Kapton film structure.

[0043] More specifically, the polytetrafluoroethylene film of the friction layer comes into contact with the silver electrode of the piezoelectric layer, and charge transfer occurs, thus forming a polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure (Kapton / Al / PTFE / Ag / PVDF / Ag / Kapton).

[0044] like Figure 4 As shown, the encapsulation layer includes a Teflon film and a polydimethylsiloxane (PDMS) layer.

[0045] Specifically, a Teflon film is disposed on the outer surface of the piezoelectric layer and the outer surface of the friction layer, forming a Teflon film / piezoelectric layer / friction layer / Teflon film structure (Telfon / piezoelectric layer / friction layer / Telfon); a polydimethylsiloxane film is disposed on the outer surface of the Teflon film, forming a polydimethylsiloxane / Teflon film / piezoelectric layer / friction layer / Teflon film / polydimethylsiloxane structure (PDMS / Telfon / piezoelectric layer / friction layer / Telfon / PDMS).

[0046] More specifically, the Teflon film covers the polytetrafluoroethylene film of the piezoelectric layer and the polyimide film of the friction layer, respectively, forming a Teflon film / polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film / Teflon film structure (Telfon / Kapton / Al / PTFE / Ag / PVDF / Ag / Kapton / Telfon).

[0047] In some of these embodiments, the thickness of the Teflon film is 100 μm.

[0048] In some of these embodiments, the thickness of the PDMS layer is 100 μm.

[0049] In some of these embodiments, the PDMS layer is Sylgard 184 silicone rubber.

[0050] Furthermore, the nanogenerator also includes an insulating layer. This insulating layer is disposed at both ends of the friction layer and is connected to both the friction layer and the piezoelectric layer.

[0051] like Figure 5 As shown, the insulating layer includes several acrylic films, which together form a spacer between the triboelectric layer and the piezoelectric layer.

[0052] Specifically, several acrylic films are symmetrically disposed at both ends of the friction layer, and each acrylic film is connected to the friction layer and the piezoelectric layer respectively.

[0053] More specifically, each acrylic film is connected to the silver electrode of the piezoelectric layer and the polytetrafluoroethylene film of the friction layer, respectively.

[0054] In some of these embodiments, the acrylic film has a thickness of 0.8 mm.

[0055] In some of these embodiments, such as Figure 6 As shown, there are several friction layers, with an insulating layer between adjacent friction layers. Specifically, the structure of the nanogenerator is: encapsulation layer / friction layer / insulating layer / ... / friction layer / insulating layer / piezoelectric layer / encapsulation layer.

[0056] like Figure 7 As shown, the fabrication method of the nanogenerator includes the following steps: (Preparation of piezoelectric layer) A silver electrode is sprayed onto the outer surface of a polyvinylidene fluoride piezoelectric film to form a silver / polyvinylidene fluoride piezoelectric film / silver structure (Ag / PVDF / Ag film). The silver / polyvinylidene fluoride piezoelectric film / silver structure is combined with a polyimide film to form a silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure (Ag / PVDF / Ag / Kapton film). (Preparation of the friction layer) Plasma etching was used to activate the surface of the polytetrafluoroethylene (PTFE) film to obtain a PTFE film with nanostructure. A polytetrafluoroethylene (PTFE) film, an aluminum electrode, and a polyimide film are combined to form a PTFE / Al / Kapton film structure. (Packaging) The silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure is combined with the polytetrafluoroethylene film / aluminum electrode / polyimide film structure to form a polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure (Kapton / Al / PTFE / Ag / PVDF / Ag / Kapton). A polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure is composited with a Teflon film to form a Teflon film / polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film / Teflon film structure (Telfon / Kapton / Al / PTFE / Ag / PVDF / Ag / Kapton / Telfon). A composite structure of Teflon film / polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film / Teflon film is formed by combining a polydimethylsiloxane film with a polydimethylsiloxane film, resulting in a polydimethylsiloxane / Teflon film / polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film / Teflon film / polydimethylsiloxane structure (PDMS / Telfon / Kapton / Al / PTFE / Ag / PVDF / Ag / Kapton / Telfon / PDMS, such as...) Figure 8 As shown), to obtain a nanogenerator (HTP-NG).

[0057] The preparation of the piezoelectric layer and the preparation of the friction layer can be carried out simultaneously or sequentially (e.g., the piezoelectric layer is prepared first and then the paper cup friction layer, or the friction layer is prepared first and then the piezoelectric layer).

[0058] The purpose of using Teflon and PDMS for encapsulation is to avoid liquid leakage and interference.

[0059] In some of these embodiments, the preparation of the Ag / PVDF / Ag film specifically involves spraying Ag onto both sides of the PVDF.

[0060] In some of these embodiments, the preparation of the Ag / PVDF / Ag / Kapton film specifically involves adhering the Ag / PVDF / Ag film onto the Kapton / PTFE film.

[0061] In some embodiments, the PTFE film with nanostructure is specifically treated with a corona discharge method to increase the effective contact area and surface charge density of the PTFE film.

[0062] In some of these embodiments, the operating parameters of the corona discharge method are sputtering gold for 30 s with a current of 20 μA, and etching parameters of 300 s, 400 W and 100 W, CF4 (30 sccm), O2 (10 sccm), and Ar (15 sccm).

[0063] In some of these embodiments, the encapsulation method using Teflon and PDMS is a wrap-around wrapping.

[0064] like Figures 9-10 As shown, a high-potential plasma region is generated around the corona needle by ionization, and the current propagates from the corona needle into the atmosphere. After corona polarization treatment, a PTFE film with a nanostructured surface is obtained, i.e., PTFE film with nanostructure.

[0065] Furthermore, the fabrication methods of nanogenerators also include: (Preparation of insulating layer) An acrylic film is placed at both ends of the polytetrafluoroethylene film / aluminum electrode / polyimide film structure to form an acrylic film / polytetrafluoroethylene film / aluminum electrode / polyimide film structure (spacer / PTFE / Al / Kapton film). The packaging also includes: The silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure is combined with the acrylic film / polytetrafluoroethylene film / aluminum electrode / polyimide film structure to form a polyimide film / aluminum electrode / polytetrafluoroethylene film / acrylic film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure (Kapton / Al / PTFE / spacer / Ag / PVDF / Ag / Kapton).

[0066] Furthermore, when there are multiple friction layers, the (encapsulation) also includes: Several acrylic film / polytetrafluoroethylene film / aluminum electrode / polyimide film structures are sequentially composited with silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structures.

[0067] The nano-electrogener of this invention can be used as a medical implant material. For example, it can be implanted in a joint to capture the biomechanical energy generated by joint movement.

[0068] The advantages of this invention are that it achieves stable DC current output by utilizing the coupling of triboelectric and piezoelectric effects, thereby providing renewable electrical energy for various electronic devices and overcoming the problems of limited storage capacity and environmental pollution of existing external power supplies; the preparation method is simple and easy to mass-produce; it has excellent performance and is fatigue-resistant, and is not easily damaged by external forces or vibrations, thus extending its working life; it has good biocompatibility and can be used as an implant material.

[0069] Example 2 This embodiment relates to the working principle and performance testing of the nanogenerator of the present invention.

[0070] like Figure 11 As shown, the working principle of the nanogenerator (HTP-NG) of this invention is a combination of triboelectric and piezoelectric effects. Specifically: In the initial state, since the piezoelectric layer is isolated from the tribological layer, there is no triboelectric potential or piezoelectric potential between the electrodes (Al electrode and Ag electrode).

[0071] When a force is applied to HTP-NG, the PVDF film bends, generating a piezoelectric potential on its surface. Simultaneously, a portion of the bent Ag layer comes into contact with the PTFE layer, leading to charge transfer between the PVDF and PTFE films due to triboelectric effects. This charge transfer creates a potential difference between the Al and Ag electrodes on the PTFE film. When the deformation of the PTFE film reaches its maximum, a new equilibrium is established where both the triboelectric and piezoelectric potentials approach their peak levels.

[0072] If an external circuit is used to connect these different electrodes, a current will be generated during the deformation of the HTP-NG. When the pressure is released, the bent PVDF membrane begins to return to its original state, so electrons flow back from the upper Ag and Al electrodes to the lower Ag electrode, which will result in a reverse current in the external circuit.

[0073] like Figure 12 As shown, HTP-NG has a stronger electromyographic conversion capability compared to a single triboelectric module or a single piezoelectric module.

[0074] For the external electrical output performance of HTP-NG, this invention uses a modal vibrator to simulate normal biomechanical motion at low frequencies for testing. For example... Figure 13 As shown, the external electrical output performance of HTP-NG is positively correlated with its working area. Specifically, when the working area of ​​HTP-NG increases from 0.5 cm × 2 cm to 2 cm × 8 cm, the voltage of HTP-NG increases from 35 V to 530 V.

[0075] For further in vitro and animal studies, taking into account both conformal size and output performance, this invention uses HTP-NG with a working area of ​​0.5 cm × 2 cm.

[0076] To assess the stability and durability of HTP-NG, this invention employs approximately 5000 mechanical stimulation cycles at a constant frequency. For example... Figures 14a-14b As shown, the power generation capacity of HTP-NG is stable, and the voltage and current of HTP-NG are stable.

[0077] To assess the hermetic properties of HTP-NG, this invention employs the method of placing HTP-NG in air and PBS solution, respectively, for testing. For example... Figure 15 As shown, the power generation performance of HTP-NG placed in PBS solution is stable compared to that placed in air, indicating that HTP-NG has good sealing performance and will not cause liquid leakage or interference.

[0078] To assess the electrical output performance of HTP-NG under different motion interventions, this invention tested it under interventions of hand tapping, elbow joint movement, and knee joint movement. For example... Figure 16 As shown, under the intervention of hand tapping, the electrical output signal of the HTP-NG is approximately 40 V. (As...) Figure 17 As shown, under the intervention of elbow joint movement, the electrical output signal of HTP-NG is approximately 10 V. (As indicated...) Figure 18 As shown, under normal knee joint movement intervention, the electrical output signal of HTP-NG is approximately 5 V; under knee joint running movement intervention, the electrical output signal of HTP-NG is approximately 10 V. This demonstrates that HTP-NG exhibits excellent electrical output performance under different movement interventions.

[0079] Regarding the implantability of HTP-NG, this invention implants sterilized HTP-NG into the anterior knee joint of rats and tests it two weeks after implantation and recovery. Figure 19 As shown, at a speed of 1 km / h, the electrical output signal of the HTP-NG is approximately 1 V to 1.5 V.

[0080] Regarding the biocompatibility of HTP-NG, this invention performs H&E histochemical staining tests on normal soft tissue and soft tissue embedded with HTP-NG (over a 2-week period). For example... Figure 20As shown, no abnormalities were observed in the soft tissue embedded with HTP-NG compared to normal soft tissue, indicating that HTP-NG has excellent biocompatibility and can be used as a biological implant material.

[0081] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0082] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for preparing a nanogenerator, characterized in that, include: Fabrication of piezoelectric layer: A silver electrode is sprayed onto the outer surface of a polyvinylidene fluoride piezoelectric film to form a silver / polyvinylidene fluoride piezoelectric film / silver structure. The silver / polyvinylidene fluoride piezoelectric film / silver structure is combined with a polyimide film to form a silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure. Preparation of friction layer: Plasma etching was used to activate the surface of a polytetrafluoroethylene (PTFE) film to obtain a PTFE film with a nanostructure. The polytetrafluoroethylene film, aluminum electrode, and polyimide film are combined to form a polytetrafluoroethylene film / aluminum electrode / polyimide film structure. Packaging: The silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure is combined with the polytetrafluoroethylene film / aluminum electrode / polyimide film structure to form a polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure. The polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure is combined with a Teflon film to form a Teflon film / polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film / Teflon film structure. The Teflon film / polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film / Teflon film structure is combined with a polydimethylsiloxane film to form a polydimethylsiloxane / Teflon film / polyimide film / aluminum electrode / polytetrafluoroethylene film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film / Teflon film / polydimethylsiloxane structure, thereby obtaining a nanogenerator.

2. The preparation method according to claim 1, characterized in that, Also includes: Preparation of insulating layer: An acrylic film is disposed at both ends of the polytetrafluoroethylene film / aluminum electrode / polyimide film structure to form an acrylic film / polytetrafluoroethylene film / aluminum electrode / polyimide film structure. The packaging also includes: The silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure is combined with the acrylic film / polytetrafluoroethylene film / aluminum electrode / polyimide film structure to form a polyimide film / aluminum electrode / polytetrafluoroethylene film / acrylic film / silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure.

3. A nanogenerator, prepared by the method according to any one of claims 1 to 2, characterized in that, include: A piezoelectric layer, comprising a polyvinylidene fluoride piezoelectric film, a silver electrode, and a polyimide film; A friction layer is disposed on one side of the piezoelectric layer and generates charge transfer with the piezoelectric layer. The friction layer includes a polytetrafluoroethylene film activated by plasma etching. An encapsulation layer covers the outer surface of the piezoelectric layer and the outer surface of the friction layer, and the encapsulation layer includes a Teflon film and a polydimethylsiloxane film.

4. The nanogenerator according to claim 3, characterized in that, The piezoelectric layer includes: Polyvinylidene fluoride piezoelectric film; A silver electrode is disposed on the surface of the polyvinylidene fluoride piezoelectric film, forming a silver / polyvinylidene fluoride piezoelectric film / silver structure; A polyimide film, wherein the polyimide film is disposed covering one side surface of the polyvinylidene fluoride piezoelectric film, forming a silver / polyvinylidene fluoride piezoelectric film / silver / polyimide film structure; and / or The friction layer includes: A polytetrafluoroethylene (PTFE) film, wherein the PTFE film is disposed on one side surface of the piezoelectric layer, and the PTFE film is activated by plasma etching. An aluminum electrode is disposed on the outer surface of the polytetrafluoroethylene film, forming a polytetrafluoroethylene film / aluminum electrode structure; A polyimide film, wherein the polyimide film covers the outer surface of the aluminum electrode and forms a polytetrafluoroethylene film / aluminum electrode / polyimide film structure; and / or The encapsulation layer includes: A Teflon film is provided to cover the outer surface of the piezoelectric layer and the outer surface of the friction layer, forming a Teflon film / piezoelectric layer / friction layer / Teflon film structure; A polydimethylsiloxane film is provided to cover the outer surface of the Teflon film, forming a polydimethylsiloxane / Teflon film / piezoelectric layer / friction layer / Teflon film / polydimethylsiloxane structure.

5. The nanogenerator according to claim 4, characterized in that, The thickness of the silver / polyvinylidene fluoride piezoelectric film / silver structure is 100 μm; and / or In the piezoelectric layer, the polyimide film has a thickness of 100 μm.

6. The nanogenerator according to any one of claims 3 to 5, characterized in that, Also includes: An insulating layer is disposed at both ends of the friction layer and connected to the friction layer and the piezoelectric layer respectively. The insulating layer includes an acrylic film.

7. The nanogenerator according to claim 6, characterized in that, The friction layer comprises several layers, and an insulating layer is disposed between two adjacent friction layers.

8. The nanogenerator according to claim 6, characterized in that, The insulating layer includes: Two acrylic films are symmetrically disposed at both ends of the friction layer, and each acrylic film is connected to the friction layer and the piezoelectric layer respectively.

9. The nanogenerator according to claim 8, characterized in that, The acrylic film has a thickness of 0.8 mm.

10. The application of a nanogenerator obtained by any of the preparation methods described in claims 1 to 2, or a nanogenerator described in any of claims 3 to 9, in the preparation of bio-implant materials.

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