阅读说明：本技术 柔性摩擦纳米发电机及无源轮胎监测系统 (Flexible friction nano generator and passive tire monitoring system ) 是由 徐婷 张不扬 于 2020-04-19 设计创作，主要内容包括：本发明涉及纳米新能源技术领域,尤其涉及一种柔性摩擦纳米发电机及无源轮胎监测系统。本发明的柔性摩擦纳米发电机包括柔性封装腔、分别固定设置在柔性封装腔两相对内壁上的两导电层,以及分别固定设置在两导电层上的两摩擦层,两导电层电性连接,两摩擦层间存在间隔距离；当以上结构在两导电层的相对方向上受压时两摩擦层能够接触产生正负静电荷,当所受压力减小时两摩擦层脱离接触,电子在两电极层间流动形成交流电。本发明的柔性摩擦纳米发电机的结构简单、耐潮、稳定性和柔性优良。本发明的无源轮胎监测系统利用本发明的柔性摩擦纳米发电机为其提供电能,进而实现在不额外接入其他电源的情况下执行监测轮胎状态的任务。(The invention relates to the technical field of nano new energy, in particular to a flexible friction nano generator and a passive tire monitoring system. The flexible friction nano generator comprises a flexible packaging cavity, two conductive layers and two friction layers, wherein the two conductive layers are respectively and fixedly arranged on two inner walls of the flexible packaging cavity, the two friction layers are respectively and fixedly arranged on the two conductive layers, the two conductive layers are electrically connected, and a spacing distance exists between the two friction layers; when the structure is pressed in the opposite direction of the two conductive layers, the two friction layers can be contacted to generate positive and negative static charges, when the pressure is reduced, the two friction layers are separated from the contact, and electrons flow between the two electrode layers to form alternating current. The flexible friction nano generator has the advantages of simple structure, moisture resistance, and excellent stability and flexibility. The passive tire monitoring system utilizes the flexible friction nano generator to provide electric energy for the passive tire monitoring system, and further realizes the task of monitoring the tire state under the condition of not additionally connecting other power supplies.)

1. A flexible triboelectric nanogenerator, comprising: the flexible packaging cavity comprises a flexible packaging cavity, a first conducting layer, a second conducting layer, a first friction layer and a second friction layer, wherein the first conducting layer, the second conducting layer, the first friction layer and the second friction layer are arranged in the flexible packaging cavity;

the first conducting layer and the second conducting layer are respectively and fixedly arranged on a group of opposite inner walls of the flexible packaging cavity, one surface of the first conducting layer, facing the second conducting layer, is fixedly provided with the first friction layer, and one surface of the second conducting layer, facing the first conducting layer, is fixedly provided with the second friction layer; the first conductive layer is electrically connected with the second conductive layer, and a spacing distance exists between the first friction layer and the second friction layer;

when the flexible packaging cavity is pressed and deformed in the opposite direction of the first conducting layer and the second conducting layer, the first friction layer and the second friction layer can be close to each other and contact with each other; when the pressure applied to the flexible packaging cavity is reduced, the first friction layer and the second friction layer can be separated from contact and are far away from each other.

2. The flexible triboelectric nanogenerator of claim 1, wherein:

the first conductive layer comprises a first flexible substrate layer and a first electrode layer, the first flexible substrate layer is fixedly arranged on the inner wall of the flexible packaging cavity, and the first electrode layer is fixedly arranged on the surface, close to the first friction layer, of the first flexible substrate layer;

and/or the second conducting layer comprises a second flexible substrate layer and a second electrode layer, the second flexible substrate layer is fixedly arranged on the inner wall of the flexible packaging cavity, and the second electrode layer is fixedly arranged on the surface, close to the second friction layer, of the second flexible substrate layer.

3. The flexible triboelectric nanogenerator of claim 2, wherein: the first flexible substrate layer and/or the second flexible substrate layer and the flexible packaging cavity are of an integrated insulating structure made of the same material.

4. The flexible triboelectric nanogenerator according to claim 2 or 3, wherein: the first friction layer and the first electrode layer are of an integral conductive structure made of the same materials or the second friction layer and the second electrode layer are of an integral conductive structure made of the same materials.

5. The flexible triboelectric nanogenerator of claim 1, wherein: the first conductive layer and/or the second conductive layer include a flexible substrate and a conductive medium mixed with the flexible substrate to form a flexible conductive film layer.

6. The flexible triboelectric nanogenerator according to any one of claims 1, 2, 3, 5, wherein: the first friction layer and/or the second friction layer are arched away from the opposite friction layer.

7. The flexible triboelectric nanogenerator of claim 1, wherein: the material of the first friction layer and the material of the second friction layer are not adjacent in a triboelectric charging sequence.

8. The flexible triboelectric nanogenerator of claim 7, wherein: the first friction layer and the second friction layer are flexible film layers, and the materials are respectively one of polytetrafluoroethylene, polydimethylsiloxane, polyimide, polyvinylidene fluoride, polyethylene terephthalate, carbon nano tubes, elastic silica gel, epoxy resin, brominated butyl rubber and nylon materials.

9. The flexible triboelectric nanogenerator of claim 1, wherein: the flexible packaging cavity is made of an insulating material and comprises at least one of rubber, silica gel, elastic resin and polyimide.

10. The flexible triboelectric nanogenerator according to any one of claims 1, 2, 3, 5, 7, 8, 9, wherein: and a micro-nano structure is arranged on one surface of the first friction layer facing the second friction layer and/or one surface of the second friction layer facing the first friction layer.

11. A passive tire monitoring system for monitoring the condition of a tire, comprising: the energy collection module, the energy management module and the sensor module are arranged in the tire and are electrically connected in sequence;

the energy collection module comprises at least one flexible friction nano-generator according to any one of claims 1 to 10, each of which is fixedly arranged on the inner surface of the tread or inner surface of the sidewall of the tire and is capable of converting the alternating current generated by the flexible friction nano-generator into direct current through an energy management module to be supplied to the sensor module, and the sensor module measures the state parameters of the tire in real time under the power supply of the energy collection module.

12. The passive tire monitoring system of claim 11, wherein: the flexible friction nano generator is fixedly arranged on the circumferential central line of the inner surface of the tire tread.

13. The passive tire monitoring system of claim 11, wherein: the flexible friction nano generator is fixedly arranged on the inner surface of the side wall, and the outer surface of the flexible packaging cavity is an arc surface which can be tightly attached to the inner surface of the side wall.

14. The passive tire monitoring system according to any one of claims 11 to 13, wherein:

a plurality of flexible friction nano generators which are connected in series and/or in parallel are fixedly arranged on the circumferential central line of the inner surface of the tire tread at equal intervals;

and/or the presence of a gas in the gas,

the flexible friction nano generators which are connected in series and/or in parallel are symmetrically arranged on the inner surfaces of the left side and the right side of the inner surface of the tire tread, and the flexible friction nano generators positioned on the same side are fixedly arranged on a circumferential ring line of the inner surface of the tire sidewall parallel to the circumferential center line at equal intervals.

15. The passive tire monitoring system according to any one of claims 11 to 13, wherein: the passive tire monitoring system further comprises a display module arranged in the vehicle and electrically connected with a vehicle-mounted power supply of the vehicle, wherein the display module is in signal connection with the sensor module, and can receive and display the state parameters of the tire measured by the sensor module.

16. The passive tire monitoring system according to any one of claims 11 to 13, wherein: the energy management module comprises a switch, a transformer, a rectifier bridge and a capacitor which are electrically connected.

Technical Field

The invention belongs to the technical field of nano new energy, and particularly relates to a flexible friction nano generator and a passive tire monitoring system.

Background

The power generation principle of the friction nanometer generator is that when two different materials are contacted under the action of mechanical force, the surfaces of the two different materials can generate positive and negative static charges under the action of contact electricity; when the two materials are separated, positive and negative charges generated by contact electrification are separated, and then an induced potential difference is generated between the electrodes of the two materials and electrons are induced; if a load is connected between the electrodes of the two materials or the two materials are in a short circuit state, the induced potential difference drives the induced electrons to flow between the two electrodes through an external circuit so as to form alternating current.

The existing friction nanometer generator is always under the continuous action of mechanical force in order to ensure that the generator can generate electricity continuously, the stability and the reliability of the structure of the generator are poor, and the mechanical property of the installation position of the generator under stress can be seriously influenced; meanwhile, the friction material or the electrode in the friction nano generator is exposed to moisture for a long time, and the electric output performance and the energy conversion efficiency of the friction nano generator are adversely affected.

Disclosure of Invention

The invention mainly aims to provide a flexible friction nano generator which is simple in structure, good in stability and flexibility and reliable in moisture resistance.

The invention also provides a passive tire monitoring system, which utilizes the flexible friction nano generator to provide electric energy for the passive tire monitoring system, thereby realizing the task of monitoring the tire state under the condition of not additionally connecting other power supplies.

The invention relates to a flexible friction nano generator, which comprises: the flexible packaging cavity comprises a flexible packaging cavity, a first conducting layer, a second conducting layer, a first friction layer and a second friction layer, wherein the first conducting layer, the second conducting layer, the first friction layer and the second friction layer are arranged in the flexible packaging cavity;

the first conducting layer and the second conducting layer are respectively and fixedly arranged on a group of opposite inner walls of the flexible packaging cavity, one surface of the first conducting layer, facing the second conducting layer, is fixedly provided with the first friction layer, and one surface of the second conducting layer, facing the first conducting layer, is fixedly provided with the second friction layer; the first conductive layer is electrically connected with the second conductive layer, and a spacing distance exists between the first friction layer and the second friction layer;

when the flexible packaging cavity is pressed and deformed in the opposite direction of the first conducting layer and the second conducting layer, the first friction layer and the second friction layer can be close to each other and contact with each other; when the pressure applied to the flexible packaging cavity is reduced, the first friction layer and the second friction layer can be separated from contact and are far away from each other.

Optionally, the first conductive layer includes a first flexible substrate layer and a first electrode layer, the first flexible substrate layer is fixedly mounted on the inner wall of the flexible packaging cavity, and the first electrode layer is fixedly mounted on a surface of the first flexible substrate layer close to the first friction layer;

and/or the second conducting layer comprises a second flexible substrate layer and a second electrode layer, the second flexible substrate layer is fixedly arranged on the inner wall of the flexible packaging cavity, and the second electrode layer is fixedly arranged on the surface, close to the second friction layer, of the second flexible substrate layer.

Optionally, the first flexible substrate layer and/or the second flexible substrate layer and the flexible encapsulation cavity are of an integrated insulating structure made of the same material.

Optionally, the first friction layer and the first electrode layer are an integral conductive structure made of the same material, or the second friction layer and the second electrode layer are an integral conductive structure made of the same material.

Optionally, the first conductive layer and/or the second conductive layer comprise a flexible substrate and a conductive medium mixed with the flexible substrate to form a flexible conductive film layer.

Optionally, the first friction layer and/or the second friction layer are arched away from the opposite friction layer.

Optionally, the material of the first friction layer and the material of the second friction layer are not adjacent in the triboelectric charging sequence.

Optionally, the first friction layer and the second friction layer are flexible film layers, and the material of each of the flexible film layers is one of polytetrafluoroethylene, polydimethylsiloxane, polyimide, polyvinylidene fluoride, polyethylene terephthalate, carbon nanotubes, elastic silica gel, epoxy resin, brominated butyl rubber, and nylon.

Optionally, the flexible packaging cavity is made of an insulating material and includes at least one of rubber, silica gel, elastic resin, and polyimide.

Optionally, a micro-nano structure is arranged on one surface of the first friction layer facing the second friction layer and/or one surface of the second friction layer facing the first friction layer.

A passive tire monitoring system for monitoring tire conditions, comprising: the energy collection module, the energy management module and the sensor module are arranged in the tire and are electrically connected in sequence;

the energy collection module comprises at least one flexible friction nano generator, each flexible friction nano generator is fixedly arranged on the inner surface of the tread or the inner surface of the sidewall of the tire and can convert alternating current generated by the flexible friction nano generator into direct current through the energy management module to be supplied to the sensor module, and the sensor module measures the state parameters of the tire in real time under the energy supply of the energy collection module.

Optionally, the flexible friction nano-generator is fixedly mounted on a circumferential centerline of the inner surface of the tread.

Optionally, the flexible friction nano-generator is fixedly mounted on the inner surface of the sidewall, and the outer surface of the flexible packaging cavity is an arc surface capable of being tightly attached to the inner surface of the sidewall.

Optionally, a plurality of flexible friction nano generators connected in series and/or in parallel are fixedly installed on the circumferential central line of the inner surface of the tread at equal intervals;

and/or the presence of a gas in the gas,

the flexible friction nano generators which are connected in series and/or in parallel are symmetrically arranged on the inner surfaces of the left side and the right side of the inner surface of the tire tread, and the flexible friction nano generators positioned on the same side are fixedly arranged on a circumferential ring line of the inner surface of the tire sidewall parallel to the circumferential center line at equal intervals.

Optionally, the passive tire monitoring system further includes a display module disposed in the vehicle and electrically connected to a vehicle-mounted power supply of the vehicle, and the display module is in signal connection with the sensor module, and can receive and display the state parameters of the tire measured by the sensor module.

Optionally, the energy management module includes an electrically connected switch, a transformer, a rectifier bridge, and a capacitor.

The invention has the beneficial effects that:

the invention discloses a flexible friction nano generator which comprises a flexible packaging cavity, a first conducting layer, a second conducting layer, a first friction layer and a second friction layer, wherein the first conducting layer and the second conducting layer are respectively and fixedly arranged on two inner walls in the flexible packaging cavity; the two conducting layers are electrically connected, and a spacing distance exists between the two friction layers made of different materials; when the structure is pressed in the opposite direction of the two conductive layers, the two friction layers can approach each other and contact each other to generate positive and negative static charges, when the pressed force is reduced, the two friction layers are separated from contact and are far away, and electrons flow between the two conductive layers to form alternating current. The flexible friction nano generator has the advantages of simple structure, moisture resistance, and excellent stability and flexibility.

Drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a cross-sectional view of one embodiment of a flexible triboelectric nanogenerator according to the invention;

FIG. 2 is a cross-sectional view of a second embodiment of a flexible triboelectric nanogenerator according to the invention;

FIG. 3 is a cross-sectional view of a third embodiment of a flexible triboelectric nanogenerator according to the invention;

FIG. 4 is a cross-sectional view of a fourth embodiment of a flexible triboelectric nanogenerator according to the invention;

FIG. 5 is a cross-sectional view of a fifth embodiment of a flexible triboelectric nanogenerator according to the invention;

FIG. 6 is a schematic structural diagram of a flexible friction nano-generator fixedly mounted on the inner surface of the tread of a tire in the passive tire monitoring system of the present invention;

FIG. 7 is a schematic structural diagram of a flexible friction nano-generator fixedly mounted on the inner surface of a sidewall of a tire in the passive tire monitoring system of the present invention;

FIG. 8 is an enlarged view of a portion of FIG. 7;

FIG. 9 is a schematic diagram of an embodiment of the passive tire monitoring system of the present invention, also illustrating the vehicle power supply.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

It is to be noted that, unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the invention pertains.

In the description of the present application, it is to be understood that the terms "length", "inner", "outer", "axial", "radial", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected or detachably connected or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The invention provides a flexible friction nano-generator, a first embodiment of which is shown in fig. 1 and comprises:

the flexible packaging cavity comprises a flexible packaging cavity 1, a first conducting layer 2, a second conducting layer 3, a first friction layer 4 and a second friction layer 5.

As shown in fig. 1, a first embodiment of the flexible friction nanogenerator of the invention is characterized in that a first conductive layer 2 and a second conductive layer 3 are respectively and fixedly arranged on a group of opposite inner walls of a flexible packaging cavity 1, a first friction layer 4 is fixedly arranged on one surface of the first conductive layer 2 facing the second conductive layer 3, and a second friction layer 5 is fixedly arranged on one surface of the second conductive layer 3 facing the first conductive layer 2; in particular, the first conductive layer 2 is electrically connected to the second conductive layer 3, and the first friction layer 4 and the second friction layer 5 are made of different materials and have a spacing distance therebetween.

When the above structure is deformed by pressure in the direction in which the first conductive layer 2 and the second conductive layer 3 are opposite (i.e. the direction in which the first friction layer 4 and the second friction layer 5 are opposite), the first friction layer 4 and the second friction layer 5 can approach each other to contact each other, and at this time, positive and negative static charges are generated on the surfaces of the two friction layers due to the contact; when the pressure applied to the structure is reduced, the first friction layer 4 and the second friction layer 5 can be separated from contact and are far away from each other, an induced potential difference is generated between the two conductive layers and induces electrons, and the induced potential difference drives the induced electrons to flow through a circuit electrically connected between the first conductive layer 2 and the second conductive layer 3 to form alternating current, so that power generation is realized.

The flexible friction nano generator has a simple structure, the flexible packaging cavity can buffer the pressure applied to the flexible friction nano generator, the conductive layer and the friction layer in the flexible friction nano generator are protected, a relatively clean and dry closed environment is provided for the internal structure, the stability and the reliability of the whole structure of the flexible friction nano generator are improved, the service life of the flexible friction nano generator is prolonged, and the electrical output performance and the energy conversion efficiency are optimized. Meanwhile, the flexible friction nano generator has excellent flexibility, and the mechanical property of the installation position of the flexible friction nano generator under stress cannot be influenced excessively.

In the above embodiments, the size of the flexible packaging cavity 1 is determined according to the specific installation and application environment, so as not to excessively affect the mechanical properties of the installation and application environment; the thickness (all the thicknesses are different from several micrometers to several hundred micrometers) and the area of the first conductive layer 2, the second conductive layer 3, the first friction layer 4 and the second friction layer 5 are adaptively adjusted according to the size of the flexible packaging cavity 1; meanwhile, the areas of the first friction layer 4 and the second friction layer 5 and the distance between the two friction layers can influence the electrical output performance of the flexible friction nano-generator, so the parameter design of the flexible friction nano-generator is determined according to specific application requirements, and the flexible friction nano-generator can meet the application requirements and has good economic performance.

In this embodiment, further, the material of the first friction layer 4 and the material of the second friction layer 5 may be different, and not adjacent to each other in the triboelectric series, and the sequence in the triboelectric series is as far as possible, so that the first friction layer 4 and the second friction layer 5 can generate more charges when contacting each other, which is more beneficial for the flexible friction nano-generator of the present invention to generate electricity. Further, the first friction layer 4 and the second friction layer 5 are provided as flexible film layers (i.e., flexible materials with small thickness), which can improve the flexibility of the structure.

Here, the material of the first friction layer 4 may be one of polytetrafluoroethylene, polydimethylsiloxane, polyimide, polyvinylidene fluoride, polyethylene terephthalate, carbon nanotube, elastic silicone, epoxy resin, brominated butyl rubber, and nylon, and the material of the second friction layer 5 may be one of the above materials, as long as it is different from the material of the first friction layer 4.

In this embodiment, further, the flexible packaging cavity 1 may be made of an insulating material including at least one of rubber, silica gel, elastic resin, and polyimide, so as to meet the flexibility requirement of the flexible packaging cavity.

The second embodiment of the invention is based on the structure of the first embodiment:

providing a first conductive layer 2 comprising a first flexible substrate layer 201 and a first electrode layer 202; the first flexible substrate layer 201 is fixedly installed on the inner wall of the flexible packaging cavity 1, and the first electrode layer 202 is fixedly installed on the surface, close to the first friction layer 4, of the first flexible substrate layer 201;

alternatively, the first and second electrodes may be,

providing a second conductive layer 3 comprising a second flexible substrate layer 301 and a second electrode layer 302; the second flexible substrate layer 301 is fixedly installed on the inner wall of the flexible packaging cavity 1, and the second electrode layer 302 is fixedly installed on the surface, close to the second friction layer 5, of the second flexible substrate layer 301;

still alternatively, the first and second substrates may be,

as shown in fig. 2, the first conductive layer 2 comprises a first flexible substrate layer 201 and a first electrode layer 202, while the second conductive layer 3 comprises a second flexible substrate layer 301 and a second electrode layer 302.

In the above structure, due to the arrangement of the first flexible substrate layer 201 and the second flexible substrate layer 301, the first conductive layer 2 and the second conductive layer 3 have flexibility, so that the flexibility of the overall structure of the flexible friction nano-generator is improved; in addition, the flexibility of the first flexible substrate layer 201 and the second flexible substrate layer 301 can be larger than the flexibility of the installation position of the flexible friction nano-generator, so that the mechanical property of the installation position of the flexible friction nano-generator under stress cannot be excessively influenced when the flexible friction nano-generator is installed.

The third embodiment of the invention is based on the structure of the second embodiment:

arranging a first flexible substrate layer 201 and a flexible packaging cavity 1 to be of an integrated insulation structure with the same material; or, the second flexible substrate layer 301 and the flexible packaging cavity 1 are arranged to be of an integrated insulation structure with the same material; further alternatively, as shown in fig. 3, the first flexible substrate layer 201, the second flexible substrate layer 301 and the flexible packaging cavity 1 are an integrated insulating structure made of the same material.

Here, it can also be understood that, when the materials of the first flexible substrate layer 201 and the second flexible substrate layer 301 are simultaneously suitable for being made into the material of the flexible packaging cavity 1, the inner wall of the flexible packaging cavity 1 can be used as the substrate of the first electrode layer 202 and the second electrode layer 302 while enclosing to form a closed cavity, so as to simplify the structure; when the materials of the first flexible substrate layer 201 and the second flexible substrate layer 301 are not suitable for the material of the flexible packaging cavity 1, the flexible substrate layers and the flexible packaging cavity 1 need to be arranged independently.

The fourth embodiment of the present invention is based on the structures of the second and third embodiments of the present invention:

the first friction layer 4 and the first electrode layer 202 are integrally formed of the same material, or the second friction layer 5 and the second electrode layer 302 are integrally formed of the same material.

As shown in fig. 4, on the basis of the structure of the embodiment shown in fig. 3 of the present invention, the second friction layer 5 and the second electrode layer 302 are provided with the integral conductive structure 6 made of the same material, so that the structure of the flexible friction nano-generator of the present invention is simplified on the premise of ensuring normal power generation.

In the present invention, the following design can also be adopted for the structures of the first conductive layer 2 and the second conductive layer 3:

the first conductive layer 2 and/or the second conductive layer 3 comprise a flexible substrate and a conductive medium mixed with the flexible substrate to form a flexible conductive film layer. For example, the flexible substrate can be a silica gel substrate with good flexibility, even a silica gel substrate subjected to vulcanization treatment, and the conductive medium can be silver-plated glass powder, or carbon nanotubes and carbon black. Of course, there is no particular limitation on the materials selected for the flexible substrate and the conductive medium, as long as the two can be mixed to form the flexible conductive film layer. At this time, the flexibility of the structures of the first conductive layer 2 and the second conductive layer 3 is improved, and the structural integrity is improved by the mixed composition mode of the flexible substrate and the conductive medium, so that the flexible substrate is more stable and reliable.

A fifth embodiment of the present invention is based on the structure of any one of the above embodiments:

the first friction layer 4 or the second friction layer 5 is provided so as to be arched away from the opposite friction layer, or as shown in fig. 5, both the first friction layer 4 and the second friction layer 5 are arched away from the opposite friction layer.

The manner in which the first and second friction layers 4, 5 can be caused to arch is numerous, for example:

when the first flexible substrate layer 201 and the second flexible substrate layer 301 are provided (as in the second embodiment of the present invention) such that they are arched away from the opposite side friction layer, the first electrode layer 202 and the second electrode layer 302 fixedly mounted on the above flexible substrate layers are also arched therewith, and the two friction layers are arched with the above electrode layers;

alternatively, when the flexible substrate layer is not separately provided, but the inner wall of the flexible packaging cavity 1 is used as the substrate (as in the third embodiment of the present invention), the inner wall of the flexible packaging cavity 1 is fixedly installed with the inner walls of two opposite conductive layers, wherein at least one inner wall of one side is recessed towards the direction far away from the inner wall of the opposite side, and the conductive layer and the friction layer fixedly installed on the inner wall of the recess are also arched along with the inner wall of the recess.

As shown in fig. 5, in the second embodiment of the present invention, two inner walls of the flexible packaging chamber 1, which are fixedly mounted with two friction layers, are recessed in a direction away from each other, and the first flexible substrate layer 201 and the second flexible substrate layer 301, which are fixedly mounted on the two inner walls, are arched in a direction away from each other, so that the first electrode layer 202 and the second electrode layer 302, which are fixedly mounted on the two flexible substrate layers, are arched, and finally, the first friction layer 4 and the second friction layer 5, which are fixedly mounted on the two electrode layers, are arched in a direction away from each other.

Here, the flexibility of the first flexible substrate layer 201 and the second flexible substrate layer 301 is greater than the flexibility of the flexible friction nano-generator of the present invention at the installation position, and meanwhile, the first flexible substrate layer 201 and the second flexible substrate layer 301 still have certain strength and have certain support capability; as shown in fig. 5, both ends of the first friction layer 4 and both ends of the second friction layer 5 abut against each other during arching, and the first flexible base layer 201 and the second flexible base layer 301 in which the friction layers are respectively located exert a supporting function, thereby supporting the entire structure.

The arrangement can ensure that a certain space is kept between the two friction layers before the two friction layers are subjected to enough pressure, otherwise, the flexible friction nano generator can not generate electricity normally.

On the basis of the structure of any one of the above embodiments, there may be provided:

one surface of the first friction layer 4 facing the second friction layer 5 and/or one surface of the second friction layer 5 facing the first friction layer 4 are/is provided with a micro-nano structure. The surface of the friction layer is provided with a micro-nano structure, so that the structure period density of the surface of the friction layer and the charge density which can be generated can be improved, and the micro-nano structure can be a patterned micro-nano structure, and/or a nano composite structure, and/or a high-density grid structure.

The invention also provides a passive tyre monitoring system for monitoring the state of a tyre, comprising:

the energy collecting module 7, the energy management module 8 and the sensor module 9 are arranged inside the tire and electrically connected in sequence.

If the flexible friction nano-generator in any of the above embodiments of the present invention is denoted as B, the tire monitored by the passive tire monitoring system of the present invention is denoted as C, and the vehicle-mounted power supply of the vehicle to which the tire C monitored by the passive tire monitoring system of the present invention belongs is denoted as D,

the energy collection module 7 comprises at least one flexible friction nano-generator B, and each flexible friction nano-generator B is fixedly arranged on the inner surface of the tread or the inner surface of the sidewall of the tire C.

The energy harvesting module 7 powers the sensor module 9 in that the energy management module 8 converts the alternating current generated by the energy harvesting module 7 into direct current to power the sensor module 9, and the sensor module 9 is capable of measuring the tire condition parameters in real time upon powering of the energy harvesting module 7.

That is, the passive tire monitoring system of the present invention can perform the task of monitoring various tire status parameters without additional access to other power sources. (except for the vehicle-mounted power supply D, the fact that no other power supply is additionally connected means that a power supply for measuring is not required to be specially arranged inside the tire for the sensor module 9.)

The process of generating ac power with respect to the energy harvesting module 7 here is:

the tyre has a contact patch when rolling;

when the flexible friction nano-generator B installed on the inner surface of the tread and/or the inner surface of the sidewall of the tire C does not enter the grounding imprint area, two friction layers inside the flexible friction nano-generator B are in a state of a spacing distance;

when the friction nano generator B arranged on the inner surface of the tread and/or the inner surface of the sidewall of the tire C gradually enters the grounding imprint area, the flexible friction nano generator B is pressed, two friction layers in the flexible friction nano generator B gradually approach to contact, and the two friction layers are in contact electrification;

when the friction nano generator B arranged on the inner surface of the tread and/or the inner surface of the sidewall of the tire C gradually leaves the grounding imprint area, the pressure borne by the flexible friction nano generator B is reduced, the two friction layers in the flexible friction nano generator B are gradually far away from the grounding imprint area and are not in contact with each other, and at the moment, electrostatic induction is generated between the two conducting layers in the friction nano generator B to form induction current;

since the flexible friction nano-generator B mounted on the inner surface of the tread and/or the inner surface of the sidewall of the tire C periodically passes through the footprint when the tire C rolls, an induced current is periodically generated to form an alternating current.

In the above embodiment, the size of the selected flexible friction nano-generator B is based on the fact that the mechanical property of the tire is not affected, the mounting position of the selected flexible friction nano-generator B is preferably based on the fact that the mass balance and the dynamic balance of the tire are not affected, and the number of the selected flexible friction nano-generators B, the electrical connection relationship (series connection and/or series-parallel connection) of a plurality of flexible friction nano-generators, the area of the friction layer in each flexible friction nano-generator B, and the interval between the two friction layers need to be designed comprehensively, so that the whole energy collection module 7 can meet the electric power required by the sensor module 9 as necessary.

In addition to the above embodiments, as shown in fig. 6, the flexible friction nano-generator B is fixedly mounted (generally, a fixed mounting manner of bonding is adopted) on the circumferential center line of the inner surface of the tread, and the above mounting position setting can reduce the influence of the flexible friction nano-generator B on the mass balance of the tire C as much as possible, and further reduce the influence on the dynamic balance of the tire C.

In another embodiment, as shown in fig. 7 and 8, when the flexible friction nano-generator B is to be fixedly mounted on the inner surface of the sidewall, the outer surface of the flexible packaging cavity 1 of the flexible friction nano-generator B can be designed to be an arc surface capable of being tightly attached to the inner surface of the sidewall, so as to ensure the reliability of the fixed connection relationship between the flexible friction nano-generator B and the inner surface of the sidewall. Generally, the flexible friction nano generator B is also fixedly mounted on the inner surface of the sidewall by means of adhesion.

On the basis of the structure of any of the above embodiments.

When the number of the flexible friction nano-generators B is several:

the flexible friction nano-generators B are arranged in series and/or parallel connection with each other and fixedly installed on the circumferential central line of the inner surface of the tread of the tire C at equal intervals, so that the dynamic balance of the tire C can be kept, and the stability of the electrical output frequency of the flexible friction nano-generators B can be ensured;

and/or the presence of a gas in the gas,

the flexible friction nano-generators B are arranged in series and/or in parallel, are symmetrically arranged on the inner surfaces of the left side and the right side of the inner surface of the tire tread, and are fixedly arranged on the circumferential ring line of the inner surface of the tire sidewall parallel to the circumferential center line of the inner surface of the tire tread at equal intervals, so that the dynamic balance of the tire and the stability of the electrical output frequency of the flexible friction nano-generators B can be kept.

Based on the structure of any of the above embodiments of the passive tire monitoring system, as shown in fig. 9, the energy management module 8 is configured to include a switch 81, a transformer 82, a rectifier bridge 83, and a capacitor 84, which are electrically connected. The switch 81 can solve the impedance mismatch problem of the electric energy collected by the flexible friction nano generator B, and improve the transfer efficiency of the electric energy; the transformer 82 can increase the output current and increase the charging speed of the capacitor 84; the ac power output from the transformer 82 is converted into dc power by the rectifier bridge 83, and then stored in the capacitor 84 to supply power to the subsequent sensor module 9.

Alternatively, as shown in fig. 9, the sensor module 9 in the passive tire monitoring system of the present invention is configured to include an RF transmitter 91, an MCU 92 and a sensor assembly 93 which are electrically connected; here, the sensor assembly 93 includes a tire pressure sensor 931 and/or a temperature sensor 932 and/or an acceleration sensor 933. In the above structure, the RF transmitter 91 can transmit the air pressure data measured by the air pressure sensor 931, the temperature data measured by the temperature sensor 932, and the acceleration data measured by the acceleration sensor 933 to the outside in the form of high-frequency filtering by means of modulation of electrical signals; the MCU microcontrol unit 92 enables in-depth control of the signal emission from the data detection by the sensor module 9. Of course, the types of sensors in the sensor assembly 93 are not limited to the above three types, and may be selected according to the type of tire parameter to be detected.

On the basis of the structure of any one of the above embodiments of the passive tire monitoring system, as shown in fig. 9, the passive tire monitoring system of the present invention further includes a display module 10 disposed in the vehicle and electrically connected to the vehicle-mounted power source D of the vehicle, the display module 10 is in signal connection with the sensor module 9, and can receive and display the state parameters of the tire measured by the sensor module 9 under the power supply of the vehicle-mounted power source D, so that the vehicle-mounted personnel, particularly the driver, can observe the state parameters of the tire in real time.

Further, the display module 10 may include an RF receiver 101, an onboard control unit 102, and an LED display screen 103, which are electrically connected. The RF receiver 101 receives the high-frequency filter transmitted by the RF transmitter 91, modulates the high-frequency filter into electrical signals of tire pressure, temperature and acceleration, analyzes and processes the electrical signals by the vehicle-mounted control unit 102 (which may be a micro control unit), and displays the electrical signals on the LED display screen 103 in a data form, or gives an alarm when an abnormal value (a value exceeding a set safety range) occurs in the data.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.