A flag-shaped triboelectric nanogenerator with internal multi-degree-of-freedom capability and a self-powered sensor

Abstract

This invention provides an internally multi-degree-of-freedom flag-shaped triboelectric nanogenerator and a self-powered sensor. The internally multi-degree-of-freedom flag-shaped triboelectric nanogenerator includes: a polytetrafluoroethylene (PTFE) film with both sides polished; a polyethylene terephthalate (PET) film, the surface of which facing the PTFE film is uniformly coated with conductive ink; the PTFE film is fixedly connected to the edges of the upper and lower PET films; when subjected to external vibration, the middle portion of the PTFE film alternately contacts and separates from the upper and lower PET films, creating a different potential difference between the two PET films at different times, allowing current to be generated under stable airflow conditions after connecting an external circuit. This invention can improve the energy density of the flag-shaped triboelectric nanogenerator, enabling even a single small flag-shaped triboelectric nanogenerator to have a large energy output.

Description

Technical Field

[0001] This invention relates to the field of self-powered technology, and more particularly to an internal multi-degree-of-freedom flag-shaped triboelectric nanogenerator and a self-powered sensor. Background Technology

[0002] With the rapid development of modern society and the advent of the artificial intelligence era, people's daily lives have become increasingly inseparable from various electronic devices. Whether it's miniature personal electronic devices or industrial production equipment, all rely on a continuous supply of electricity. The energy shortage problem has become increasingly serious, urgently requiring the development of machinery and equipment that can utilize renewable energy to alleviate the problems caused by the shortage of traditional energy sources. Renewable energy sources such as wind, ocean, and acoustic energy all have large reserves, wide distribution, and are pollution-free, possessing significant utilization value. However, the current utilization rate of renewable energy development technologies is low. Therefore, exploring new ways to utilize renewable energy is of paramount importance for promoting healthy social development and solving energy shortages.

[0003] Currently, existing new energy technologies mainly consist of solar power and fuel cell power. However, solar power is limited by various environmental factors, such as temperature, humidity, and altitude, making large-scale deployment difficult. Fuel cells are limited by fuel carrying capacity and safety issues. Both can only solve the energy shortage problem to a certain extent. Against this backdrop, new self-powered technologies have emerged. These new self-powered technologies collect environmental energy such as wind, vibration, and sound to power sensors and microelectronic devices, offering a possibility for solving the energy shortage problem. Traditional self-powered technologies mainly rely on the photoelectric effect, piezoelectric effect, and electromagnetic induction effect. Although these technologies can achieve self-powering of equipment, the devices are large, costly, and complex, making it difficult to drive further development of self-powered technologies.

[0004] Triboelectric nanogenerators, based on the coupling of triboelectricity and electrostatic induction, have been proposed in recent years. They feature high output efficiency, simple fabrication processes, low manufacturing costs, and a clean, pollution-free energy conversion process. Furthermore, through different structural designs, they can be widely applied to the harvesting of various types of environmental energy, showing great promise for future environmental energy harvesting and new energy utilization. Currently, triboelectric nanogenerators are widely used in environmental energy harvesting, converting collected environmental energy into electrical energy to power electronic devices.

[0005] Wind energy, as one of the most widely available clean energy sources in nature, can be converted into electrical energy through the design of suitable triboelectric nanogenerator structures, effectively alleviating the energy shortage problem faced by society today. Existing designs for wind energy harvesting, such as flag-shaped triboelectric nanogenerators, suffer from low energy density and low output efficiency due to the small area of ​​the flags. The only way to improve overall output efficiency is to connect multiple flags in series and parallel to power sensor nodes and electronic devices. This approach increases the size of the overall power generation device, and the excessive external circuitry can easily lead to wiring problems, thus reducing the durability of the triboelectric nanogenerator. Summary of the Invention

[0006] To address the aforementioned technical problems of low energy density and low output efficiency in existing flag-shaped triboelectric nanogenerators, this invention provides an internally multi-degree-of-freedom flag-shaped triboelectric nanogenerator and a self-powered sensor. This invention can improve the energy density of flag-shaped triboelectric nanogenerators, enabling even a single small flag-shaped triboelectric nanogenerator to achieve significant energy output efficiency.

[0007] The technical means employed in this invention are as follows:

[0008] An internally multi-degree-of-freedom flag-shaped triboelectric nanogenerator, characterized by comprising:

[0009] A polytetrafluoroethylene film, wherein both sides of the polytetrafluoroethylene film are sanded.

[0010] A polyethylene terephthalate film, wherein the polyethylene terephthalate film is respectively laid on the upper and lower surfaces of the polytetrafluoroethylene film, and conductive ink is uniformly coated on the surface of any polyethylene terephthalate film facing the polytetrafluoroethylene film.

[0011] The polytetrafluoroethylene film is fixedly connected to the edges of the upper and lower polyethylene terephthalate films;

[0012] When subjected to external vibration, the middle part of the polytetrafluoroethylene (PTFE) film alternately contacts and separates from the upper and lower polyethylene terephthalate (PET) films, thereby generating triboelectric charging that makes the PTFE film negatively charged, while the PET films on both sides become positively charged. Due to the different distances between the PTFE film and the PET films on both sides during the movement, there is a potential difference between the PET films on both sides. When connected to an external circuit, current can be generated under stable air intake conditions.

[0013] Furthermore, a number of soft, fine pads are uniformly arranged along the length direction and perpendicular to the length side on one side of the polyethylene terephthalate film coated with conductive ink.

[0014] Furthermore, the polytetrafluoroethylene film is divided into a first part and a second part in the length direction, wherein the width of the second part is smaller than that of the first part.

[0015] Furthermore, the second part is uniformly cut into several strip structures in the width direction.

[0016] Furthermore, the length of the first portion of the polytetrafluoroethylene film accounts for 7 / 50-11 / 50 of the total length of the polyethylene terephthalate film.

[0017] Furthermore, a frame-shaped flexible insulating layer is adhered to the edge of any one side of the polytetrafluoroethylene film to prevent the conductive ink layers on both sides of the polytetrafluoroethylene film from coming into contact with each other and causing a short circuit.

[0018] Furthermore, the width of the frame-shaped flexible insulating layer is 5mm.

[0019] Furthermore, the triboelectric nanogenerator also includes wires for connecting the conductive ink layer on the polyethylene terephthalate film to achieve electrical energy output.

[0020] The present invention also discloses a self-powered sensor, including a rectifier circuit, a sensing device, and an internal multi-degree-of-freedom flag-shaped triboelectric nanogenerator as described in any of the above.

[0021] The electrical energy generated by the internal multi-degree-of-freedom flag-shaped triboelectric nanogenerator is transmitted through wires to a rectifier circuit for rectification, and then used to power the sensing device.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] This invention optimizes the original flag-shaped triboelectric nanogenerator three times: modifying the wind-induced vibration film, adding a padding layer to the conductive ink layer, and increasing the degrees of freedom by cutting the wind-induced vibration film. For example, in a flag size of 7cm*14cm, the original flag-shaped triboelectric nanogenerator without any treatment has an open-circuit voltage of 24V, a short-circuit current of 2μA, and a transferred charge of 14nC under an ambient wind speed of 11.1m / s. After being modified with 1200-grit sandpaper, the wind-induced vibration film has an open-circuit voltage of 35V, a short-circuit current of 2.82μA, and a transferred charge of 31nC under the same conditions. Furthermore, after adding a padding layer to the conductive ink layer, the open-circuit voltage is 37.5V, the short-circuit current is 2.89μA, and the transferred charge is 34nC. Furthermore, after increasing the degrees of freedom by cutting the wind-induced vibration film, at the optimal degrees of freedom, the open-circuit voltage is 78V, the short-circuit current is 7.0μA, and the transferred charge is 72nC. The output performance of the flag-shaped triboelectric nanogenerator has been significantly improved. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is an exploded view of the internal multi-degree-of-freedom flag-shaped triboelectric nanogenerator structure of the present invention.

[0026] Figure 2 This is a schematic diagram of the shape of the polytetrafluoroethylene film in its flat state according to the present invention.

[0027] Figure 3 This is a schematic diagram of the shape of the polytetrafluoroethylene film under vibration state according to the present invention.

[0028] Figure 4 This is a schematic diagram of the self-powered sensor structure of the present invention.

[0029] In the figure: 1. Polyethylene terephthalate film, 2. Conductive ink layer, 3. Soft fine pad, 4. Polytetrafluoroethylene film, 401. First part, 402. Second part, 5. Flexible insulating layer. Detailed Implementation

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0034] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0035] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0036] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0037] This invention discloses an internally multi-degree-of-freedom flag-shaped triboelectric nanogenerator, comprising a polytetrafluoroethylene (PTFE) film 4 and a polyethylene terephthalate (PET) film 1. Both sides of the PTFE film 4 are sanded. The PET film 1 is respectively applied to the upper and lower surfaces of the PTFE film 4, and conductive ink is uniformly coated on the surface of any PET film facing the PTFE film to form an ink layer 2. The edges of the PTFE film 4 and the upper and lower PET films 1 are fixedly connected. When subjected to external vibration, the middle portion of the PTFE film 4 alternately contacts and separates from the upper and lower PET films 1, thereby generating relative friction and leading to electron movement and current generation. In a preferred embodiment of this invention, 1200-grit sandpaper is used to sand the PTFE film 4. Theoretically, the sanded PTFE film 4 can achieve its function, but the higher the grit of the sandpaper, the better the modification effect. The choice of 1200 grit sandpaper here is based on a combination of cost and treatment effect; in reality, only sandpaper modification treatment is needed.

[0038] Furthermore, a plurality of soft, fine pads are uniformly arranged along the length direction and perpendicular to the length edge on one side of the polyethylene terephthalate film 1 coated with conductive ink. Preferably, two pairs of soft, fine pads are preferred; too many soft, fine pads will make it difficult for the PET film and PTFE film on both sides to make complete contact and generate frictional charge.

[0039] Furthermore, the polytetrafluoroethylene film 4 is divided into a first part and a second part in the length direction, wherein the width of the second part is smaller than that of the first part, such as... Figure 2 As shown. Furthermore, the second part is uniformly cut into several strip-shaped structures in the width direction, such as... Figure 3 As shown.

[0040] Specifically, the length of the first part should be much shorter than the length of the second part. Experimental observations show that, under airflow conditions, the flag-shaped triboelectric nanogenerator will bend for the first time at a point 11 / 50 of the distance from the fixed position at the base of the flag. This causes the internal PTFE film to slap against the PET film. Therefore, to make the strip-cutting method effective, it is necessary to cut the strip before 11 / 50 of the distance from the base. If the strip is too long, the internal PTFE film is prone to curling, causing a short circuit in the carbon layers on both sides of the PET film and resulting in a loss of power generation capability. Therefore, in this application, the length of the first part of the polytetrafluoroethylene film accounts for 7 / 50-11 / 50 of the length of the polyethylene terephthalate film; in a preferred embodiment, a ratio of 1 / 5 is preferable.

[0041] In addition, the PTFE film and PET film in this application are of similar size, and preferably the total length of the inner PTFE film is slightly shorter than that of the PET film, with the difference not exceeding 5 mm. This length should not exceed the width of the flexible insulation layer to avoid short circuits caused by contact between the two PET films and to allow the PTFE film to move freely without a fixed side.

[0042] In such Figure 3 In the preferred embodiment shown, the second part is preferably cut into 5 strip structures evenly in the width direction. In practice, the number of strip structures can vary depending on the actual situation. Experimental observations show that when the number of strip structures gradually increases from 1 to 5, the performance of the triboelectric nanogenerator in generating electrical energy gradually improves. When the number of strip structures gradually decreases from 5 to 8, the performance of the triboelectric nanogenerator in generating electrical energy gradually decreases. Therefore, in this embodiment, 5 strip structures are preferred.

[0043] Furthermore, a frame-shaped flexible insulating layer is adhered to the edge of any one side of the polytetrafluoroethylene film to prevent the conductive ink layers on both sides of the polytetrafluoroethylene film from coming into contact with each other and causing a short circuit.

[0044] Furthermore, the width of the frame-shaped flexible insulating layer is 5mm.

[0045] Furthermore, the triboelectric nanogenerator also includes wires for connecting the conductive ink layer on the polyethylene terephthalate film to achieve electrical energy output.

[0046] The structure of the above-mentioned triboelectric nanogenerator will be further explained below with specific application examples and accompanying drawings.

[0047] like Figure 1 As shown, this invention provides an internally multi-degree-of-freedom flag-shaped triboelectric nanogenerator, mainly composed of five thin films. The middle film is a polytetrafluoroethylene (PTFE) film 4 with a surface treated with 1200-grit sandpaper, preferably with a thickness of 0.08 mm. The two outer films of the PTFE film 4 are polyethylene terephthalate (PET) films 1, preferably with a thickness of 25 μm. Conductive ink 2 is brushed onto one side of the PET film. The conductive ink layer can completely cover the PET film layer to ensure conductivity; theoretically, the thinner the conductive ink layer, the better. The side of the PET 1 brushed with conductive ink 2 is opposite to the PTFE 4, forming a PET-PTFE-PET dual-electrode triboelectric nanogenerator. The PTFE film serves as the friction layer, and the PET films brushed with conductive ink on both sides serve as both conductive and friction layers.

[0048] Furthermore, on the side of the polyethylene terephthalate film 1 with the conductive ink layer 2 brushed on, two pairs of fine pads 3 are pasted, the material of which is required to be a soft pad.

[0049] Furthermore, to prevent the conductive ink layers 2 brushed on the polyethylene terephthalate film 1 on both sides of the polytetrafluoroethylene film 4 from coming into contact and causing a short circuit due to the reduced width of the middle polytetrafluoroethylene film 4, a flexible insulating layer 5 must be bonded to one side of any polyethylene terephthalate film 1 brushed with conductive ink 2. In this embodiment, transparent tape is preferably used as the insulating layer, and a ring-shaped insulating layer with a width of 5mm is attached around the outer side of the polyethylene terephthalate film 1.

[0050] Furthermore, in order to increase the contact and separation effect between the middle polytetrafluoroethylene layer 4 and the two sides of polyethylene terephthalate film 1, the middle polytetrafluoroethylene film 4 is uniformly cut to increase the degree of freedom. The cutting starts from the side of the polytetrafluoroethylene film opposite the flagpole and cuts towards the flagpole side. The cutting length ends when the cutting length reaches 4 / 5 of the total length of the film, forming multiple strips of polytetrafluoroethylene film with the same length and width.

[0051] Furthermore, the two conductive ink layers brushed onto the polyethylene terephthalate film are processed, and wires are led out from one end of the conductive layer near the flagpole side. A total of two wires are led out from the two conductive layers for the electrical output of the triboelectric nanogenerator. The four sides of the entire flag-shaped triboelectric nanogenerator are held together by an adhesive (this patent uses ordinary double-sided tape as the adhesive).

[0052] This invention also discloses a self-powered sensor, such as... Figure 4 As shown, it includes a rectifier circuit, a sensing device, and an internal multi-degree-of-freedom flag-shaped triboelectric nanogenerator as described in any of the above; the electrical energy generated by the internal multi-degree-of-freedom flag-shaped triboelectric nanogenerator is transmitted through wires to the rectifier circuit for rectification and then supplies power to the sensing device.

[0053] The aforementioned flag-shaped triboelectric nanogenerator can power miniature sensor nodes or electronic devices by harvesting ambient wind energy. The specific principle is as follows:

[0054] When the wind blows from a certain direction, the entire flag vibrates, causing the PTFE film strips inside to vibrate freely. This vibrates and alternately strikes the polyethylene terephthalate (PET) films on both sides, creating a triboelectric effect that makes the PTFE film negatively charged and the PET films on both sides positively charged. Due to the different relative distances between the PTFE film and the PET films on both sides during the movement, there is a potential difference between the PET films on both sides. When an external circuit is connected, current can be generated under stable airflow conditions. By connecting to an external load circuit, power can be supplied to external micro-sensor nodes or electronic devices.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flag-shaped triboelectric nanogenerator with internal multi-degree-of-freedom characteristics, characterized in that: include: Polytetrafluoroethylene film (4), both sides of the polytetrafluoroethylene film (4) are sanded. A polyethylene terephthalate film (1) is provided on the upper and lower surfaces of the polytetrafluoroethylene film (4), and conductive ink is uniformly coated on the surface of any polyethylene terephthalate film (1) facing the polytetrafluoroethylene film (4). Several soft, fine pads (3) are uniformly arranged along the length direction and perpendicular to the length side on one side of the polyethylene terephthalate film (1) coated with conductive ink. The polytetrafluoroethylene film (4) is fixedly connected to the edges of the upper and lower polyethylene terephthalate films (1); The polytetrafluoroethylene film (4) is divided into a first part (401) and a second part (402) in the length direction, wherein the width of the second part (402) is smaller than that of the first part (401), and the second part (402) is uniformly cut into 5 strip structures in the width direction; When subjected to external vibration, the middle part of the polytetrafluoroethylene film (4) alternately contacts and separates from the upper and lower polyethylene terephthalate films (1), thereby generating triboelectric charging that makes the polytetrafluoroethylene film (4) negatively charged and the polyethylene terephthalate films (1) on both sides positively charged. Due to the different distances between the polytetrafluoroethylene film (4) and the polyethylene terephthalate films (1) on both sides during the movement, there is a potential difference between the polyethylene terephthalate films (1) on both sides. After connecting an external circuit, current can be generated under stable air intake conditions.

2. The internal multi-degree-of-freedom flag-shaped triboelectric nanogenerator according to claim 1, characterized in that, The length of the first portion (401) of the polytetrafluoroethylene film (4) accounts for 7 / 50-11 / 50 of the total length of the polyethylene terephthalate film (1).

3. The internal multi-degree-of-freedom flag-shaped triboelectric nanogenerator according to claim 1, characterized in that, A frame-shaped flexible insulating layer (5) is attached to the edge of any one side of the polytetrafluoroethylene film (4) to prevent the conductive ink layers (2) on both sides of the polytetrafluoroethylene film (4) from coming into contact with each other and causing a short circuit.

4. The internal multi-degree-of-freedom flag-shaped triboelectric nanogenerator according to claim 3, characterized in that, The width of the frame-shaped flexible insulating layer (5) is 5 mm.

5. The internal multi-degree-of-freedom flag-shaped triboelectric nanogenerator according to claim 1, characterized in that, The triboelectric nanogenerator also includes a wire for connecting a conductive ink layer (2) on the polyethylene terephthalate film (1) to achieve electrical energy output.

6. A self-powered sensor, characterized in that, Includes a rectifier circuit, a sensing device, and an internal multi-degree-of-freedom flag-shaped triboelectric nanogenerator as described in any one of claims 1-5; The electrical energy generated by the internal multi-degree-of-freedom flag-shaped triboelectric nanogenerator is transmitted through wires to a rectifier circuit for rectification, and then used to power the sensing device.

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