Triboelectric nanogenerator, sensing system, and sensing method

Abstract

The application discloses a friction nanogenerator, a sensing system and a sensing method. The friction nanogenerator comprises a rotor assembly, a stator assembly, a rotating shaft and an impeller assembly. The rotor assembly is relatively rotated with the stator assembly through the rotating shaft. The stator assembly comprises a supporting seat and a first friction layer. The rotor assembly comprises a rotating disc, a double-way shape memory alloy and a second friction layer. The rotating disc is fixedly connected with the impeller assembly. The second friction layer is oppositely arranged with the first friction layer. The double-way shape memory alloy is in a first state and a second state respectively when being at different temperatures. The friction areas of the first friction layer and the second friction layer are different when the double-way shape memory alloy is in the first state and the second state. The impeller assembly drives the rotating disc to rotate around the rotating shaft. The rotating disc drives the double-way shape memory alloy and the second friction layer to rotate. The second friction layer rotates and generates electric charges by friction with the first friction layer. The friction nanogenerator can simultaneously monitor wind speed and wind temperature.

Description

Technical Field

[0001] This invention relates to the field of generator technology, and more specifically, to a triboelectric nanogenerator, a sensing system, and a sensing method. Background Technology

[0002] With the development of power Internet of Things (IoT) technology, a large number of micro- and nano-sensors are widely used in the field of online equipment monitoring. Providing stable and reliable continuous power to these sensors is a prerequisite for their normal operation. Currently, micro- and nano-sensors are mainly powered by batteries, but battery power has drawbacks such as limited battery life, the need for periodic replacement, and environmental pollution. Since micro- and nano-sensors operate at power levels in the microwatt / milliwatt range, the mechanical energy widely available in the environment becomes a potential energy source.

[0003] Triboelectric nanogenerators based on triboelectric and electrostatic induction coupling effects can convert mechanical energy into electrical energy, providing a new approach for micro-energy harvesting and conversion.

[0004] In transformer systems, it is necessary to monitor the transformer's operating temperature in real time to avoid overheating and safety risks. Therefore, setting up a self-powered sensing system is crucial for the power industry. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a triboelectric nanogenerator, sensing system, and sensing method capable of simultaneously monitoring wind speed and wind temperature.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A triboelectric nanogenerator includes a rotor assembly, a stator assembly, a shaft, and an impeller assembly. The rotor assembly and the stator assembly are respectively connected to the shaft, and the rotor assembly rotates relative to the stator assembly via the shaft. The stator assembly includes a support base and a first friction layer disposed on the support base. The rotor assembly includes a turntable, a two-way shape memory alloy connected to the turntable, and a second friction layer stacked on the two-way shape memory alloy. The turntable is fixedly connected to the impeller assembly, and the second friction layer and the first friction layer are disposed opposite to each other. The two-way shape memory alloy has a first state and a second state, and the two-way shape memory alloy is in the first state and the second state respectively when it is at different temperatures. When the two-way shape memory alloy is in the first state and the second state, the friction areas of the first friction layer and the second friction layer are different. The rotation of the impeller assembly drives the turntable to rotate around the shaft, and the rotation of the turntable drives the two-way shape memory alloy and the second friction layer to rotate. The second friction layer generates electric charge through friction with the first friction layer.

[0008] The present invention also provides a sensing system, including the triboelectric nanogenerator and sensor as described above; the sensor is electrically connected to the second triboelectric layer; the sensor is used to monitor the charge generated by the second triboelectric layer, and to monitor wind speed and / or wind temperature based on the charge.

[0009] The present invention also provides a sensing method for the sensing system as described above, comprising: measuring a first relationship curve between the frequency of the charge generated by the triboelectric nanogenerator and the wind speed; measuring a second relationship curve between the amount of charge generated by the triboelectric nanogenerator and the wind temperature; comparing the real-time frequency of the charge generated by the triboelectric nanogenerator with the first relationship curve to obtain real-time wind speed information; and comparing the real-time amount of charge generated by the triboelectric nanogenerator with the second relationship curve to obtain real-time wind temperature information.

[0010] Implementing the embodiments of the present invention will have the following beneficial effects:

[0011] This invention utilizes the fact that a two-way shape memory alloy exists in a first state and a second state at different temperatures. The friction areas of the first and second friction layers in the first state and the second state are different. This difference in friction area leads to a difference in the amount of charge generated through friction, allowing wind temperature to be monitored by analyzing the output power of the triboelectric nanogenerator. Furthermore, different wind speeds cause the impeller assembly to rotate at different speeds around its axis, resulting in different rotation speeds of the second friction layer. This causes the frequency of charge generation through friction between the second and first friction layers to differ, allowing wind speed to be monitored by analyzing the frequency of the output electrical signal from the triboelectric nanogenerator. Attached Figure Description

[0012] 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] in:

[0014] Figure 1a This is a schematic diagram of the overall structure of a triboelectric nanogenerator according to a specific embodiment of the present invention.

[0015] Figure 1b This is a schematic diagram of the structure of a two-way shape memory alloy in a specific embodiment of the present invention, showing the transition between the first and second states.

[0016] Figure 2 This is an equivalent structural diagram of a triboelectric nanogenerator according to a specific embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram illustrating the working principle of a sensing system according to a specific embodiment of the present invention.

[0018] Figure 4 The triboelectric nanogenerators prepared in Examples 1 and Comparative Examples 1-3 of this invention have hot airflows (6 m·s) at different temperatures. -1 Comparison of the effective voltage values ​​generated under ( ) conditions.

[0019] Figure 5 This is the curve showing the relationship between the real-time frequency of the charge generated by the triboelectric nanogenerator in Embodiment 3 of the present invention and the wind speed.

[0020] Figure 6 This is the curve showing the relationship between the real-time charge generated by the triboelectric nanogenerator in Embodiment 4 of the present invention and the wind temperature. Detailed Implementation

[0021] 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. 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.

[0022] Please refer to Figures 1a-1b , Figure 1a This is a schematic diagram of the overall structure of a triboelectric nanogenerator according to a specific embodiment of the present invention. Figure 1b This is a schematic diagram illustrating the structure of a two-way shape memory alloy undergoing alternating transitions between its first and second states, according to a specific embodiment of the present invention. A triboelectric nanogenerator 10 includes a rotor assembly 11, a stator assembly 12, a shaft 13, and an impeller assembly 14. The rotor assembly 11 and the stator assembly 12 are respectively connected to the shaft 13, and the rotor assembly 11 rotates relative to the stator assembly 12 via the shaft 13. Figure 1a The stator assembly 12 includes a support base 121 and a first friction layer 122 disposed on the support base 121. The rotor assembly 11 includes a turntable 111, a two-way shape memory alloy 112 connected to the turntable 111, and a second friction layer 113 stacked on the two-way shape memory alloy 112. The turntable 111 is fixedly connected to the impeller assembly 14. The second friction layer 113 and the first friction layer 122 are disposed opposite to each other.

[0023] In one specific embodiment, the triboelectric nanogenerator 10 includes a stator assembly 12 and a rotor assembly 11 stacked on the stator assembly 12. The stator assembly 12 includes a support base 121 and a first friction layer 122 covering the support base. The rotor assembly 11 includes a turntable 111, a two-way shape memory alloy 112 disposed circumferentially on the turntable 111 and extending radially along the turntable 111, and a second friction layer 113 disposed on one side surface of the two-way shape memory alloy 112 opposite to the first friction layer 122. The rotor assembly 11 and the stator assembly 12 are fixedly connected to a rotating shaft 13. The rotor assembly 11 is fixedly connected to an impeller assembly 14. Wind power drives the impeller assembly 14 to rotate. The rotation of the impeller assembly 14 causes the turntable 111 to move in a circular motion around the rotating shaft 13. The turntable 111 drives the two-way shape memory alloy 112 and the second friction layer 113 to rotate, thereby realizing the rotation of the rotor assembly 11 in a circular direction. The rotation of the second friction layer 113 generates electric charge through friction with the first friction layer 122.

[0024] In one specific embodiment, the rotor assembly 11 and the stator assembly 12 are obtained by 3D printing technology.

[0025] In one specific embodiment, the two-way shape memory alloy 112 has a ring structure, with an inner diameter of 4cm to 4.5cm, an outer diameter of 6cm to 6.5cm, and an included angle of 45° to 50°.

[0026] It should be understood that Figure 1 only shows that there are 4 two-way shape memory alloys 112, but it is not limited to this. The number of two-way shape memory alloys 112 can also be 1, 2, 3, 5, etc., which is not limited here. It is only required that the second friction layer on the two-way shape memory alloy 112 can generate charge with the first friction layer through friction.

[0027] In one specific embodiment, the impeller assembly 14 includes a wind turbine 141 and a wind turbine 141 support arm 142.

[0028] In one specific embodiment, the wind turbine 141 has a hemispherical structure.

[0029] It should be understood that the impeller 141 is not limited to a hemispherical structure, but can also be a fan-shaped structure, a square structure, etc. There is no limitation here, as long as the impeller assembly 14 can drive the turntable to rotate around the axis.

[0030] In one specific embodiment, the support base 121 is a disc with a radius of 5cm to 8.5cm.

[0031] In one specific embodiment, the first friction layer 122 is a PI film.

[0032] In one specific embodiment, the PI film comprises the following components in weight percentages: 49% to 49.5% of 4,4-(hexafluoroisopropene)phthalic acid (6FTA), 49% to 49.5% of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFDB), and 1% to 2% of PbTiO3.

[0033] When the triboelectric nanogenerator 10 is in the high-temperature environment of the transformer, the charge generated by the friction of the friction layer is easily dissipated into the environment through thermionic emission, resulting in a significant reduction in the output performance of the triboelectric nanogenerator 10. The PI film, as the first friction layer 122, is attached to the surface of the support 121 as the stator. By introducing strong electron-withdrawing groups, such as trifluoromethyl and sulfone groups, and doping with PbTiO3, the triboelectric charge density and thermal charge stability of the film are improved, effectively improving the output stability of the triboelectric nanogenerator 10 at high temperatures.

[0034] In one specific embodiment, the support base 121 is a copper foil.

[0035] In one specific embodiment, the second friction layer 113 is rabbit skin.

[0036] Specifically, rabbit skin is used as a second friction layer 113 on the side of the two-way shape memory alloy 112 near the stator. This not only serves as a friction layer but also prevents the two-way shape memory alloy 112 from directly rubbing against the stator, thus extending the service life of the triboelectric nanogenerator 10.

[0037] Furthermore, such as Figure 1b The two-way shape memory alloy 112 includes a first state and a second state. The two-way shape memory alloy 112 will be in the first state and the second state respectively when it is at different temperatures. When the two-way shape memory alloy 112 is in the first state and the second state, the friction areas of the first friction layer 122 and the second friction layer 113 are different.

[0038] In one specific embodiment, the two-way shape memory alloy 112 is arc-shaped in the first state and sheet-shaped in the second state.

[0039] Specifically, the two-way shape memory alloy 112 is in an arc-shaped first state and a flat sheet-like second state at different temperatures. The friction areas of the first friction layer 122 and the second friction layer 113 in the first state are different from those in the second state, resulting in different amounts of charge generated by friction.

[0040] In one specific embodiment, the friction area of ​​the first friction layer 122 and the second friction layer 113 when the two-way shape memory alloy 112 is in the first state is smaller than the friction area of ​​the first friction layer 122 and the second friction layer 113 when the two-way shape memory alloy 112 is in the second state.

[0041] In one specific embodiment, the phase transformation temperature of the two-way shape memory alloy 112 is 50°C to 200°C.

[0042] In one specific embodiment, the two-way shape memory alloy 112 is a NiTi two-way shape memory alloy.

[0043] Please continue to refer to Figure 1a The impeller assembly 14 rotates, causing the turntable 111 to rotate around the shaft 13. The rotation of the turntable 111 causes the double-pass shape memory alloy 112 and the second friction layer 113 to rotate. The second friction layer 113 rotates and generates charge through friction with the first friction layer 122.

[0044] In one specific embodiment, four electrodes 15 are also provided on the support base 121, and the electrodes 15 are electrically connected to the support base 121 to form a current loop.

[0045] In one specific embodiment, the electrode 15 is disposed on the side of the support 121 opposite to the first friction layer 122. The electrode 15 is electrically connected to the support 121 through a wire. The four electrodes 15 are symmetrical about the center of the support and the polarities of adjacent electrodes 15 are opposite.

[0046] Specifically, Figure 2 This is a schematic diagram of the equivalent structure of the triboelectric nanogenerator of the present invention. Since the generation of charge in this generator is achieved through the friction between the first friction layer 122 and the second friction layer 113, the working principle of the generator is explained here only by taking a cross-sectional view of the contact area between the two as an example. Figure 2 In (i)-(iv), the first friction layer 122 and the second friction layer 113 have opposite polarities. Under the action of wind, the two-way shape memory alloy 112 and the second friction layer 113 rotate, and the second friction layer 113 will rub against the first friction layer 122. Through the opposite polarity electrodes 15 connected to the load, electrons flow from one electrode 15 to the other electrode 15, causing a periodic change in potential between the first friction layer 122 and the second friction layer 113, thereby forming a current. As the two-way shape memory alloy 112 and the second friction layer 113 continue to rotate, Figure 2 The process (i)-(iv) will repeat cyclically.

[0047] This invention also discloses a sensing system, such as Figure 3 , Figure 3This is a schematic diagram of the working principle of the sensing system of the present invention, including a triboelectric nanogenerator 10 and a sensor 20 as in any embodiment of the present invention; the sensor 20 is electrically connected to the triboelectric nanogenerator 10; the sensor 20 is used to monitor the charge generated by the triboelectric nanogenerator 10, and to monitor the wind speed and / or wind temperature based on the charge.

[0048] In one specific embodiment, the sensor 20 includes an energy storage unit 21, a wind temperature monitoring unit 22, and a wind speed monitoring unit 23.

[0049] In one specific embodiment, the energy storage unit 21 is used to receive and store the charge generated by the triboelectric nanogenerator 10 and to power the wind temperature monitoring unit 22 and the wind speed monitoring unit 23.

[0050] In one specific embodiment, the wind temperature monitoring unit 22 is used to analyze the magnitude of the charge to monitor the wind temperature.

[0051] Specifically, the two-way shape memory alloy 112 in the triboelectric nanogenerator 10 will be in a first state and a second state at different temperatures. The friction areas of the first friction layer 122 and the second friction layer 113 in the first state are different from those in the second state. The difference in friction area leads to a difference in the amount of charge generated by friction. Therefore, the wind temperature can be monitored by analyzing the amount of charge in the triboelectric nanogenerator 10.

[0052] In one specific embodiment, the wind temperature monitoring unit 22 can preset a threshold value for the amount of charge generated by the triboelectric nanogenerator 10 corresponding to the wind temperature. The wind temperature monitoring unit 22 can determine whether the amount of charge exceeds the preset threshold value. If it does not exceed the threshold value, the wind temperature monitoring unit 22 will not output a signal. If it exceeds the preset threshold value, the wind temperature monitoring unit 22 will output an abnormality and issue an alarm.

[0053] In one specific embodiment, the wind speed monitoring unit 23 is used to analyze the frequency of the charge to monitor the wind speed.

[0054] Specifically, by using different wind speeds, the impeller assembly 14 in the triboelectric nanogenerator 10 rotates at different speeds around the shaft 13. As a result, the second friction layer 113 rotates at different speeds due to the rotation of the impeller assembly 14. This causes the rotation frequency of the second friction layer 113 to be different from that of the first friction layer 122 through friction to generate charges. Therefore, the wind speed can be monitored by analyzing the frequency of the charges in the triboelectric nanogenerator 10.

[0055] The present invention also discloses a sensing method for a sensor 20, wherein the sensor 20 is a sensor 20 as described in any embodiment of the present invention, comprising the following steps:

[0056] 1) The first curve showing the relationship between the frequency of the charge generated by the triboelectric nanogenerator 10 and the wind speed was measured.

[0057] 2) The second relationship curve between the amount of charge generated by the triboelectric nanogenerator 10 and the wind temperature was determined.

[0058] 3) Compare the real-time frequency of the charge generated by the triboelectric nanogenerator 10 with the first relationship curve to obtain real-time wind speed information.

[0059] Specifically, the second friction layer 113 in the triboelectric nanogenerator 10 rotates at different speeds due to different wind speeds, resulting in a different frequency of rotation between the second friction layer 113 and the first friction layer 122 generating charges through friction. Based on the first relationship curve between the frequency of the charges generated by the triboelectric nanogenerator 10 and the wind speed, real-time wind speed information is obtained by monitoring the real-time frequency of the charges generated by the triboelectric nanogenerator 10.

[0060] 4) Compare the real-time charge generated by the triboelectric nanogenerator 10 with the second relationship curve to obtain real-time wind temperature information.

[0061] Specifically, the friction areas of the first friction layer 122 and the second friction layer 113 differ due to different wind temperatures, resulting in different real-time electrical charges generated by friction. Based on the second relationship curve between the electrical charge generated by the triboelectric nanogenerator 10 and the wind temperature, real-time wind temperature information can be obtained by monitoring the real-time electrical charge generated by the triboelectric nanogenerator 10.

[0062] The following are specific examples.

[0063] Example 1

[0064] The triboelectric nanogenerator structure in this embodiment is shown in Figure 1. The triboelectric nanogenerator includes a rotor assembly, a stator assembly, a shaft, and an impeller assembly. The rotor assembly and the stator assembly are respectively connected to the shaft, and the rotor assembly rotates relative to the stator assembly through the shaft. The stator assembly includes a copper foil with a radius of 6 cm and a PI film with a thickness of 50 μm disposed on the copper foil. The PI film includes 49% 6FTA, 49% TFDB, and 2% PbTiO3. The rotor assembly includes a turntable, four NiTi two-way shape memory alloys connected to the turntable, and rabbit skins respectively stacked on the four NiTi two-way shape memory alloys. The turntable is fixedly connected to the impeller assembly, and the rabbit skins and PI films are disposed opposite to each other. The NiTi two-way shape memory alloys are arc-shaped in the first state and sheet-shaped in the second state. The friction area between the rabbit skin and the PI film when the NiTi two-way shape memory alloys are arc-shaped is smaller than the friction area between the rabbit skin and the PI film when the NiTi two-way shape memory alloys are sheet-shaped. The phase transition temperature of NiTi two-way shape memory alloy is 50℃~200℃. The arc-shaped NiTi two-way shape memory alloy has an inner diameter of 4cm, an outer diameter of 6cm, and an included angle of 45°. Four electrodes are also set on the copper foil, which is located on the side of the copper foil facing away from the PI film. The electrodes are electrically connected to the copper foil through wires. The four electrodes are symmetrical about the center of the support base, and the polarities of adjacent electrodes are opposite.

[0065] The triboelectric nanogenerator of this embodiment is electrically connected to the sensor, which is used to monitor the charge generated by the triboelectric nanogenerator and monitor the wind speed and wind temperature based on the charge.

[0066] The sensors include an energy storage unit, a wind temperature monitoring unit, and a wind speed monitoring unit.

[0067] The energy storage unit is used to receive and store the charge generated by the triboelectric nanogenerator and to power the wind temperature monitoring unit and the wind speed monitoring unit.

[0068] The wind temperature monitoring unit is used to analyze the magnitude of the charge to monitor the wind temperature.

[0069] The wind speed monitoring unit is used to analyze the frequency of the charge to monitor wind speed.

[0070] Comparative Example 1

[0071] Comparative Example 1 differs from Example 1 only in that it does not include NiTi two-way shape memory alloy.

[0072] Comparative Example 2

[0073] Comparative Example 2 differs from Example 1 only in that the PI film is not doped with PbTiO3. Specifically, the PI film comprises the following components by mass percentage: 50% 6FTA and 50% TFDB.

[0074] Comparative Example 3

[0075] Comparative Example 3 differs from Example 1 only in that the PI film comprises the following components by mass percentage: 50% pyromellitic dianhydride and 50% 4,4'-diaminodiphenyl ether.

[0076] Test Example 1

[0077] The output response of the triboelectric nanogenerator 10 of Example 1 and Comparative Examples 1-3 was tested at different temperatures.

[0078] The triboelectric nanogenerators of Example 1 and Comparative Examples 1-3 were tested at different temperatures for hot airflow (6 m·s⁻¹). -1 The output current in ) . The test results are as follows Figure 4 , Figure 4 The triboelectric nanogenerators of Embodiment 1 and Comparative Examples 1-3 of the present invention are hot airflows (6 m·s) at different temperatures. -1 A comparison chart of the effective voltage values ​​generated under these conditions.

[0079] according to Figure 4 The test results show that the triboelectric nanogenerator of Example 1 can still maintain an effective output voltage of 2.18V at 200℃. This is because the PI film of Example 1, by introducing strong electron-withdrawing groups and doping with PbTiO3, improves the triboelectric charge density and thermal charge stability of the film, which effectively improves the output stability of the triboelectric nanogenerator at high temperature. In addition, the NiTi two-way shape memory alloy can be restored to a flat sheet shape at high temperature to adjust the friction area between the PI film and the rabbit skin, which can avoid the reduction of the output performance of the triboelectric nanogenerator under high temperature conditions.

[0080] Test Example 2

[0081] The sensing system of Example 1 was used to monitor wind speed.

[0082] The sensing system of Example 1 was placed in a closed-loop wind tunnel control device to test the relationship curve between the real-time frequency of the charge and the wind speed, and the result was as follows: Figure 5 The curve showing the relationship between the real-time frequency of the charge generated by the triboelectric nanogenerator of Embodiment 1 of the present invention and the wind speed is based on... Figure 5 The results show that the real-time frequency of the charge increases linearly with the increase of airflow speed. This is because different wind speeds cause the impeller assembly 111 in the triboelectric nanogenerator to rotate at different speeds around the shaft 112, which in turn causes the rabbit skin to rotate at different speeds, resulting in different real-time frequencies of the charge generated by friction. Therefore, the sensing system of the present invention can monitor the wind speed by analyzing the real-time frequency of the charge.

[0083] Test Example 3

[0084] The sensing system of Example 1 was used to monitor wind temperature.

[0085] The sensing system of Example 1 was placed in a wind tunnel to test the real-time charge density versus wind temperature curve, and the results were as follows: Figure 6 The curve showing the relationship between the real-time charge generated by the triboelectric nanogenerator of Embodiment 1 of the present invention and the wind temperature is based on... Figure 6 The results show that the real-time charge level decreases linearly with increasing airflow temperature, and its fitting curve r 2 =0.96893, showing a linear relationship. Meanwhile, the triboelectric nanogenerator of Embodiment 1 of this invention still exhibits a high output charge density at a high temperature of 200°C. Due to the thermionic emission effect, electrons transferred to the dielectric surface are released into the vacuum after triboelectric charging (CE), causing the output of the triboelectric nanogenerator to decay. However, the NiTi two-way shape memory alloy used in this invention changes from an arc shape to a flat sheet shape as the wind temperature increases, increasing the friction area and ensuring the stable output of the triboelectric nanogenerator at high temperatures. Therefore, the sensing system of this invention can monitor the wind temperature by analyzing the real-time charge density.

[0086] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A triboelectric nanogenerator, characterized in that, It includes a rotor assembly, a stator assembly, a shaft, and an impeller assembly. The rotor assembly and the stator assembly are respectively connected to the shaft, and the rotor assembly rotates relative to the stator assembly through the shaft. The stator assembly includes a support base and a first friction layer disposed on the support base; The rotor assembly includes a turntable, a two-way shape memory alloy connected to the turntable, and a second friction layer stacked on the two-way shape memory alloy. The turntable is fixedly connected to the impeller assembly, and the second friction layer and the first friction layer are disposed opposite to each other. The two-way shape memory alloy includes a first state and a second state. The two-way shape memory alloy will be in the first state and the second state respectively when it is at different temperatures. When the two-way shape memory alloy is in the first state and the second state, the friction areas of the first friction layer and the second friction layer are different. The rotation of the impeller assembly drives the turntable to rotate around the shaft, and the rotation of the turntable drives the two-way shape memory alloy and the second friction layer to rotate. The rotation of the second friction layer generates an electric charge through friction with the first friction layer. The shape of the two-way shape memory alloy in the first state is arc-shaped; The two-way shape memory alloy is in a sheet-like shape in the second state; The two-way shape memory alloy is in the first state and the second state at different temperatures. The friction area of ​​the first friction layer and the second friction layer in the first state is different from that in the second state. The difference in friction area leads to a difference in the amount of charge generated by friction. Therefore, the wind temperature can be monitored by analyzing the amount of charge generated by the triboelectric nanogenerator.

2. The triboelectric nanogenerator according to claim 1, characterized in that, The friction area of ​​the first friction layer and the second friction layer of the two-way shape memory alloy in the first state is smaller than the friction area of ​​the first friction layer and the second friction layer of the two-way shape memory alloy in the second state.

3. The triboelectric nanogenerator according to claim 2, characterized in that, The phase transformation temperature of the two-way shape memory alloy is 50℃~200℃.

4. The triboelectric nanogenerator according to claim 3, characterized in that, The two-way shape memory alloy is a NiTi two-way shape memory alloy.

5. The triboelectric nanogenerator according to claim 1, characterized in that, The first friction layer is a PI film; The thickness of the PI film is 50μm~55μm; The second friction layer is rabbit skin; The support base is made of copper foil; The impeller assembly includes a rotor and a rotor support arm, the rotor being connected to the shaft via the rotor support arm; the rotor has a hemispherical structure. The support base is also provided with electrodes, which are electrically connected to the support base to form a current loop.

6. The triboelectric nanogenerator according to claim 5, characterized in that, The PI film comprises the following components by mass percentage: 49%~49.5% of 4,4-(hexafluoroisopropene)diphthalic acid, 49%~49.5% of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 1%~2% of PbTiO3.

7. A sensing system, characterized in that, Including the triboelectric nanogenerator and sensor as described in any one of claims 1 to 6; The sensor is electrically connected to the triboelectric nanogenerator; The sensor is used to monitor the charge generated by the triboelectric nanogenerator and to monitor wind speed and / or wind temperature based on the charge.

8. The sensing system according to claim 7, characterized in that, The sensor includes an energy storage unit, a wind temperature monitoring unit, and a wind speed monitoring unit; The energy storage unit is used to receive and store the charge generated by the triboelectric nanogenerator and to power the wind temperature monitoring unit and the wind speed monitoring unit. The wind temperature monitoring unit is used to analyze the magnitude of the charge in order to monitor the wind temperature; The wind speed monitoring unit is used to analyze the frequency of the charge in order to monitor the wind speed.

9. A sensing method for a sensing system as described in any one of claims 7-8, characterized in that, include: The first relationship curve between the frequency of the charge generated by the triboelectric nanogenerator and the wind speed was determined. The second relationship curve between the amount of charge generated by the triboelectric nanogenerator and the wind temperature was determined. The real-time frequency of the charge generated by the triboelectric nanogenerator is compared with the first relationship curve to obtain real-time wind speed information; The real-time charge generated by the triboelectric nanogenerator is compared with the second relationship curve to obtain real-time wind temperature information.

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