A contact electrification device

Abstract

Disclosed is a contact electrification device, which comprises a vacuum cavity; a first friction member and a second friction member, the first friction member and the second friction member being located in the vacuum cavity, the first friction member and the second friction member being capable of contact and relative movement, the first friction member obtaining electrons and the second friction member losing electrons when the relative movement occurs; and an electron generator, the electron generator being located in the vacuum cavity and being used for applying electrons to the second friction member. The device enhances the driving force of charge transfer by injecting exogenous electrons into materials by means of an electron beam in a vacuum environment, and effectively improves the contact electrification efficiency and the amount of accumulated charges.

Description

Technical Field

[0001] This utility model relates to the field of nanoenergy and systems, and optionally to a contact electrification device. Background Technology

[0002] The principle of contact electrification is that contact polarization is generated through charge transfer at the material interface. Since contact electrification is achieved by electron transfer when two materials are forced to approach atomically close distances, the outermost atoms of the material can acquire a corresponding charge. Furthermore, the additional charge on the surface atoms is significantly less shielded than that on the bulk atoms due to the incompleteness and asymmetry of the surrounding electron cloud distribution. Therefore, unlike other materials with high charge (such as piezoelectric and ferroelectric materials), tribopolarized materials possess extremely high electric field strengths and have wide applications: in sensors, they can sensitively detect changes in the environment (such as gases and biomolecules); in electronic devices, they can regulate carrier concentration and optimize the performance of field-effect transistors; in the energy field, they facilitate charge separation in solar cells and storage in supercapacitors; and they can also be applied to triboelectric nanogenerators to efficiently harvest mechanical energy, serving as one of the key mechanisms for constructing novel functional devices.

[0003] However, charge transfer in traditional contact electrification is driven by the difference in the work function (the ability of a material to bind electrons) between the two materials. But if the difference in work function is small, the driving force for electron transfer is insufficient, resulting in a limited amount of charge transferred in each contact. Simultaneously, the generated charge is easily leaked through interaction with the surrounding environment, thus reducing the effective charge. Therefore, traditional contact electrification devices suffer from low electrification efficiency. Utility Model Content

[0004] The purpose of this invention is to overcome the problem of low contact electrification efficiency in the existing technology and to provide a contact electrification device. This device enhances the charge transfer driving force by injecting exogenous electrons into the material using an electron beam in a vacuum environment, thereby effectively improving the contact electrification efficiency and charge accumulation.

[0005] To achieve the above objectives, this utility model provides a contact electrification device, comprising: Vacuum cavity; A first friction element and a second friction element are located inside the vacuum cavity. The first friction element and the second friction element are able to contact each other and move relative to each other. When the relative movement occurs, the first friction element gains electrons and the second friction element loses electrons. An electron generator, located within the vacuum chamber, is used to apply electrons to the second friction element.

[0006] Preferably, the electron generator is a thermionic emission electron gun, and the electron generator is located above the second friction member.

[0007] Preferably, the thermionic emission gun is a gridless thermionic emission gun.

[0008] Preferably, the contact electrification device further includes a rotating platform, a support, a first driver, and a second driver. The rotating platform, the support, the first driver, and the second driver are located inside the vacuum chamber. The second friction element is fixed on the rotating platform, and the first friction element is fixed on the support. The second driver is used to drive the rotating platform to move up and down, so that the first friction element and the second friction element make contact or disengage. The first driver is used to drive the rotating platform to rotate, so that the first friction element and the second friction element move relative to each other when they are in contact, or to move the second friction element below the electron generator.

[0009] Preferably, the first driver is a programmable motor.

[0010] Preferably, the second driver is a miniature vibration motor, which is built into the rotary table.

[0011] Preferably, the vacuum cavity is provided with an openable transparent viewing window.

[0012] Preferably, the vacuum chamber is connected to a two-stage vacuum system, which includes a mechanical pump and a molecular pump. Preferably, the contact energizing device further includes a vacuum pressure gauge and a vacuum gauge for monitoring the vacuum status.

[0013] Preferably, the vacuum chamber is provided with a vacuum aviation interface, and the mechanical pump, molecular pump, vacuum pressure gauge and vacuum gauge are fixed to the corresponding flange on the vacuum chamber through the vacuum aviation interface by flange connection.

[0014] Through the above technical solution, the contact electrification device of this utility model includes an electron generator, which can apply electrons to the second friction element (i.e., the electron-depleted material). These extra electrons are not the valence electrons of the electron-depleted material molecules themselves, but rather "external" charges injected through external energy (electron beam). Due to the filling of surface state energy levels and the repulsive effect between charges in the local negative charge region, the binding force of these extra electrons on the surface of the electron-depleted material is significantly weakened. This will bring a stronger charge transfer driving force and may lead to more significant electron transfer, thereby accumulating more static charge, thus effectively improving the contact electrification efficiency and charge accumulation. In this process, contact electrification can cause the outermost atoms of the material to carry corresponding charges. In addition, the extra charge of the surface atoms is significantly less shielded than that of the atoms in the bulk phase due to the incompleteness and asymmetry of the surrounding electron cloud distribution. Therefore, unlike the charging of other materials (such as piezoelectric and ferroelectric materials), tribopolarized materials have extremely high electric field strength. In sensors, it can sensitively detect changes in the environment (such as gases and biomolecules); when used in electronic devices, it can regulate carrier concentration and optimize the performance of field-effect transistors; in the energy field, it can assist in charge separation in solar cells and storage in supercapacitors; it can also be applied to triboelectric nanogenerators to efficiently harvest mechanical energy, and is one of the key mechanisms for constructing novel functional devices. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the contact electrification device of this utility model; Figure 2 A schematic diagram illustrating the working mechanism of the contact electrification device of this utility model; Figure 3 A schematic diagram illustrating the principle of traditional contact electrification; Figure 4 A schematic diagram illustrating the working mechanism of the contact electrification device of this utility model; Figure 5 This is a flowchart describing the working process of the contact energizing device of this utility model.

[0016] Explanation of reference numerals in the attached figures 1 Mechanical pump; 2 Molecular pump; 3 Vacuum gauge; 4 Pressure gauge; 5 Electronic generator; 6 Sample rack; 7 Rotary stage; 8 First friction element; 9 Second friction element; 10 Polyurethane foam; 11 Vibration motor; 12 Rotary stage; 13 Vacuum chamber. Detailed Implementation

[0017] The optional embodiments of this utility model are described in detail below with reference to the accompanying drawings. It should be understood that the optional embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0018] In this utility model, unless otherwise stated, directional terms such as "up," "down," "left," and "right" generally refer to the direction of reference to the drawing paper or the direction of gravity relative to the device in normal use; "inner" and "outer" refer to the space between the interior and exterior of the vacuum chamber; and "far" and "near" refer to the spatial distance relative to the component mounting base or a designated reference point.

[0019] Figure 1 A schematic diagram of a contact electrification device according to the present invention is shown. Figure 2 A schematic diagram illustrating the working mechanism of the contact electrification device according to this utility model is provided. For example... Figure 1 , Figure 2 As shown, this utility model provides a vacuum electron beam assisted contact electrification device, which includes: a vacuum cavity 13; a first friction element 8 and a second friction element 9, the first friction element 8 and the second friction element 9 being located inside the vacuum cavity 13, the first friction element 8 and the second friction element 9 being able to contact each other and undergo relative movement, during the relative movement, the first friction element 8 gains electrons and the second friction element 9 loses electrons; and an electron generator 5, the electron generator 5 being located inside the vacuum cavity 13, for applying electrons to the second friction element 9.

[0020] Specifically, the vacuum chamber 13 can be manufactured using CNC (Computer Numerical Control) machining, and the chamber has pre-installed interfaces for accessories such as a vacuum gauge 3, a molecular pump 2, a flange aviation plug, and a pressure gauge 4. The vacuum chamber 13 also features a switchable quartz window (not shown in the figure) for easy observation of the interior and sample placement. The vacuum chamber 13 is connected to a two-stage vacuum system, including a mechanical pump 1 and a molecular pump 2, which are connected to the vacuum chamber 13 via an ISO interface. The mechanical pump 1 is used for initial vacuuming, reducing the chamber pressure from atmospheric pressure to the activation threshold of the molecular pump 2; the molecular pump 2 is used to further increase the vacuum level, achieving a high-vacuum environment to avoid contamination of the contact electrostatic surface and charge leakage by air humidity and dust.

[0021] Optionally, the electron generator 5 can be a thermionic emission electron gun, located above the second friction element 9. With this arrangement, the electron generator 5 can directionally emit an electron beam onto the surface of the second friction element 9. Specifically, the thermionic emission electron gun is preferably a gridless thermionic emission electron gun, which emits thermionic electrons under the action of an accelerating electric field by heating the cathode (such as a metal wire) to the emission temperature, and then forming an electron beam through a focusing structure. Electron beam irradiation can cause the second friction element 9 (a de-electron material) to accumulate a large number of exogenous electrons, resulting in an electron-rich state.

[0022] Optionally, the contact electrification device further includes a rotating platform 7, a support 6, a first driver, and a second driver, all located within the vacuum chamber 13. The second friction element 9 is fixed to the rotating platform 7, and the first friction element 8 is fixed to the support 6. The second driver drives the rotating platform 7 to move up and down, causing the first friction element 8 and the second friction element 9 to contact or disengage; the first driver drives the rotating platform 7 to rotate, causing relative movement between the first friction element 8 and the second friction element 9 during contact, or moving the second friction element 9 below the electron generator 5.

[0023] Specifically, the first driver is a programmable motor used to drive the rotary table 7 to rotate periodically. The second driver is a miniature vibration motor 11, which is built into the rotary table 7. Polyurethane foam 10 is installed on the surface of the rotary table 7 to provide vibration damping and cushioning. The second friction element 9 (such as a nylon film) is attached to the surface of the polyurethane foam 10. The first friction element 8 (such as fluorocrystalline mica) is fixed on the bracket 6, maintaining a certain gap with the second friction element 9, but can contact and separate under the action of the vibration motor 11.

[0024] Optionally, the vacuum chamber 13 is equipped with a vacuum aviation interface. The mechanical pump 1, molecular pump 2, vacuum gauge 3, and pressure gauge 4 are fixed to the corresponding flanges on the vacuum chamber 13 via the vacuum aviation interface using a flange connection method, ensuring vacuum sealing and modularity of the components. The vacuum gauge 3 and pressure gauge 4 are used to monitor the vacuum status inside the vacuum chamber 13 in real time, and the monitoring can be manually switched: the pressure gauge 4 is observed during the low vacuum stage, and the vacuum gauge 3 is switched during the high vacuum stage.

[0025] Figure 3 The diagram shown is a schematic of the traditional contact electrification principle. Figure 4 The diagram illustrates the operating principle of a vacuum electron beam assisted contact power generation device, as follows: Figure 3 , Figure 4 As shown, this invention provides a vacuum electron beam assisted contact electrification method that overcomes the shortcomings of traditional contact electrification, such as "insufficient driving force, small amount of charge, slow speed, and easy leakage," by "enhancing driving force through external electron injection + suppressing leakage in a high vacuum environment + improving accumulation speed through active injection." This method addresses the four dimensions of "power, total amount, speed, and stability of charge transfer," ultimately achieving "high electrification efficiency."

[0026] Figure 5The diagram shows a contact polarization process assisted by a vacuum electron beam provided by this utility model, including: evacuating the vacuum chamber, irradiating the electron-depleting material with an electron beam, rotating the sample stage to align the irradiated electron-depleting material with the electron-gaining material, starting the vibration motor to make contact between the electron-depleting material and the electron-gaining material to generate electricity, and achieving tribopolarization on the electron-gaining material after multiple cycles.

[0027] Specifically, the vacuum chamber is evacuated, and mechanical pump 1 is started to pre-evacuate the inlet pipes of vacuum chamber 13 and molecular pump 2, reducing the pressure to the starting threshold of molecular pump 2. Subsequently, molecular pump 2 is started, and with the continuous evacuation of mechanical pump 1, the chamber pressure is increased to the required high vacuum.

[0028] Specifically, the electron beam irradiates the electron-depleting material and the second friction material: the power supply to the electron generator 5 is turned on, the cathode is heated to the emission temperature, an accelerating electric field is applied to emit and accelerate electrons, and an electron beam is formed through a focusing structure. The electron beam irradiates the second friction element 9 (electron-depleting material) for an appropriate time, causing its surface to accumulate a large amount of additional negative charge (i.e., exogenous electrons), and it is in an electron-rich state.

[0029] Specifically, the contact electrification process involves: activating the first driver (programmable motor) to rotate the rotary table 7, causing the portion of the second friction element 9, irradiated by the electron beam, to move directly below the first friction element 8. Simultaneously, activating the second driver (micro-vibration motor 11) causes the second friction element 9 to contact and separate from the first friction element 8, resulting in triboelectric electrification. Due to the electron enrichment on the surface of the second friction element 9, and the weakening of electron binding force caused by surface state energy level filling and charge repulsion in local negative charge regions, the charge transfer driving force is enhanced, thereby accumulating more negative charge on the first friction element 8.

[0030] Specifically, after multiple cycles, tribopolarization is achieved on the electron material. After a period of time, the vibration motor 11 is turned off, the programmable motor is restarted, and the unirradiated portion of the second friction element 9 is rotated to below the electron generator 5 for electron beam irradiation. At the same time, the irradiated portion is rotated to below the first friction element 8 for contact charging. By repeating this process multiple times, efficient tribopolarization can be achieved on the first friction element 8.

[0031] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention. For example, the gridless thermionic emission electron gun can be replaced with other types of electron sources. Various optional technical features can be combined in any suitable manner. For example, the optional types of electron-losing and electron-gaining materials can be selected and replaced according to the triboelectric series table. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A contact energizing device, comprising: Vacuum cavity; A first friction element and a second friction element are located inside the vacuum cavity. The first friction element and the second friction element are able to contact each other and move relative to each other. When the relative movement occurs, the first friction element gains electrons and the second friction element loses electrons. An electron generator, located within the vacuum chamber, is used to apply electrons to the second friction element.

2. The contact electrification device according to claim 1, characterized in that, The electron generator is a thermionic emission electron gun, and the electron generator is located above the second friction element.

3. The contact electrification device according to claim 2, characterized in that, The thermionic emission electron gun is a gridless thermionic emission electron gun.

4. The contact electrification device according to claim 1, characterized in that, The contact electrification device further includes a rotary table, a support, a first driver, and a second driver, all of which are located within the vacuum chamber. The second friction element is fixed on the rotary table, and the first friction element is fixed on the bracket. The second driver is used to drive the rotary table to move up and down, so that the first friction element and the second friction element come into contact or disengage; The first driver is used to drive the rotary table to rotate, so that the first friction member and the second friction member move relative to each other when they come into contact, or to move the second friction member below the electron generator.

5. The contact electrification device according to claim 4, characterized in that, The first driver is a programmable motor.

6. The contact electrification device according to claim 4, characterized in that, The second driver is a miniature vibration motor, which is built into the rotary table.

7. The contact electrification device according to claim 1, characterized in that, The vacuum chamber is equipped with a switchable transparent viewing window.

8. The contact electrification device according to claim 1, characterized in that, The vacuum chamber is connected to a two-stage vacuum system, which includes a mechanical pump and a molecular pump.

9. The contact electrification device according to claim 8, characterized in that, The contact electrification device also includes a vacuum pressure gauge and a vacuum gauge for monitoring the vacuum status.

10. The contact electrification device according to claim 9, characterized in that, The vacuum chamber is equipped with a vacuum aviation interface, and the mechanical pump, molecular pump, vacuum pressure gauge and vacuum gauge are fixed to the corresponding flanges on the vacuum chamber through the vacuum aviation interface by flange connection.

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