Frictional power generation device, self-powered sensor, and energy providing device

Abstract

The present disclosure provides a triboelectric generator with constant intrinsic capacitance, comprising: a triboelectric pair, comprising a first triboelectric layer and a second triboelectric layer arranged oppositely, the first triboelectric layer and the second triboelectric layer being made of different materials; and an electrode pair, comprising a first electrode and a second electrode, the first electrode and the second electrode being arranged oppositely and being movable between the first triboelectric layer and the second triboelectric layer, wherein the first electrode and the second electrode are arranged longitudinally oppositely and the relative position and surface area of the first electrode and the second electrode are fixed, the electrode pair formed by the first electrode and the second electrode is capable of moving transversely in the space between the first triboelectric layer and the second triboelectric layer arranged longitudinally oppositely at a constant speed so as to enter and exit, wherein the first electrode is in contact with the first triboelectric layer and the second electrode is in contact with the second triboelectric layer. The present disclosure also provides a self-powered sensor and an energy providing device.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a triboelectric generator with constant intrinsic capacitance, a self-powered sensor and an energy providing device. BACKGROUND

[0002] Triboelectricity (contact electrification) is a well-known phenomenon that the contact or friction between two materials can make the surfaces of the two materials charged. In recent years, with the increasing demand for distributed power supply, the triboelectric nanogenerator (TENG) based on triboelectricity and electrostatic induction has become a new type of mechanical energy collection device, which has been used in traditional energy collection devices, sensors, flexible devices, etc.

[0003] The triboelectric nanogenerator utilizes the contact electrification and electrostatic induction phenomenon to obtain energy from the environment, and has the advantages of high output power, high energy conversion efficiency, good scalability, high stability and flexibility, and low cost. Good matching between mechanical motion frequency and circuit characteristic frequency is the key to the high output performance of TENG. However, the existing TENG usually adopts an intrinsic capacitance varying with time, which hinders the effective design of good matching.

[0004] The generator mechanism of TENG mainly includes two processes: contact electrification of triboelectric materials and change of potential difference between electrodes. Based on this generator mechanism, there are currently various working modes of TENG, among which the common ones are: contact-separation mode (CS-TENG), lateral sliding mode, single motor mode and independent friction layer mode. In order to improve the power conversion efficiency of TENG, many studies focus on material selection, structure design and power management circuit, etc. However, the common TENG usually works in contact-separation mode or lateral sliding mode, and has an intrinsic capacitance varying with time, which hinders the effective design of device parameters and cannot effectively convert mechanical motion into electrical energy. SUMMARY

[0005] In order to solve one of the above technical problems, the present disclosure provides a triboelectric generator with constant intrinsic capacitance, a self-powered sensor and an energy providing device.

[0006] According to one aspect of the present disclosure, a triboelectric generator with constant intrinsic capacitance comprises:

[0007] a friction pair comprising a first friction layer and a second friction layer arranged oppositely, the first friction layer and the second friction layer being made of different materials and capable of being charged with opposite charges; and

[0008] an electrode pair comprising a first electrode and a second electrode, the first electrode and the second electrode being isolated and movable between the first friction layer and the second friction layer,

[0009] wherein the first electrode and the second electrode are longitudinally opposite and the relative position and surface area of the first electrode and the second electrode are fixed, the electrode pair comprising the first electrode and the second electrode is able to move laterally at a constant speed in the space between the longitudinally opposite first friction layer and second friction layer in order to enter and exit, wherein the first electrode is in contact with the first friction layer and the second electrode is in contact with the second friction layer.

[0010] According to at least one embodiment of the present disclosure, the contact surface of the first friction layer is the same in shape and / or size as the contact surface of the first electrode, and the contact surface of the second friction layer is the same in shape and / or size as the contact surface of the second electrode.

[0011] According to at least one embodiment of the present disclosure, the materials of the first friction layer and the second friction layer are PET or PVC, respectively, and / or the first electrode and the second electrode are made of Cu film.

[0012] According to at least one embodiment of the present disclosure, each power generation cycle of the triboelectric generator comprises:

[0013] (1) contact electrification occurs at the contact surfaces of the first friction layer and the second friction layer, the electrode pair is inserted into the space between the first friction layer and the second friction layer at the constant speed, so that the two closely attached are separated to form a quasi-uniform electric field therebetween;

[0014] (2) the electrode pair moves in the space between the first friction layer and the second friction layer at the constant speed, and the current flows from one of the first electrode and the second electrode to the other electrode;

[0015] (3) the electrode pair reaches an overlap position fully overlapping the contact surfaces of the first friction layer and the second friction layer, and the current is zero; and

[0016] (4) the electrode pair leaves the friction pair from the overlap position at the constant speed, and the current flows from the other electrode to the one electrode.

[0017] According to at least one embodiment of the present disclosure, the number of friction pairs is multiple, and the number of electrode pairs is one or more, the friction pairs and the electrode pairs constitute a disc-shaped triboelectric generator, and the friction pairs and the electrode pairs are arranged to be able to rotate relative to each other so that the electrode pairs are away from or enter the space between the first friction layer and the second friction layer of each friction pair.

[0018] According to at least one embodiment of the present disclosure, each two friction pairs arranged adjacently in the disc-shaped triboelectric generator have opposite polarities.

[0019] According to at least one embodiment of the present disclosure, the number of friction pairs is m, and the number of electrode pairs is n, where m = n > 1.

[0020] According to at least one embodiment of the present disclosure, the disc is evenly divided into 2m regions, and each region is provided with one friction pair.

[0021] According to at least one embodiment of the present disclosure, each power generation cycle of the triboelectric generator includes:

[0022] (1) Contact electrification occurs at the contact surface of the first friction layer and the second friction layer, and the electrode pair is inserted into the space between the first friction pair at the constant speed;

[0023] (2) The electrode pair moves in the space between the first friction pair at the constant speed, and the electromotive force linearly increases;

[0024] (3) The electrode pair completely overlaps the contact surface of the first friction pair, and the electromotive force reaches a maximum value;

[0025] (4) The electrode pair continues to move and insert into the second friction pair at the constant speed, and the electromotive force gradually decreases, and when half the length of the electrode pair is inserted into the second friction pair, the electromotive force is zero;

[0026] (5) The electrode pair continues to move at the constant speed, and when the electrode pair completely overlaps the contact surface of the second friction pair, the electromotive force reaches a maximum value;

[0027] (6) The electrode pair continues to move at the constant speed, and the electromotive force repeats the above changes.

[0028] According to another aspect of the present disclosure, a self-powered sensor includes the triboelectric generator as claimed in any one of the above to provide electrical energy for the sensor.

[0029] According to still another aspect of the present disclosure, an energy providing device includes the triboelectric generator as claimed in any one of the above to provide energy. BRIEF DESCRIPTION OF DRAWINGS

[0030] The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description thereof, serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0031] Figure 1 This is a schematic diagram of a triboelectric power generation device according to one embodiment of the present disclosure.

[0032] Figure 2 The power generation cycle of a triboelectric power generation device according to an embodiment of the present disclosure is shown.

[0033] Figure 3 The relationship between the open-circuit voltage and electrode displacement of the CIC-TENG is shown.

[0034] Figure 4 Numerical simulations and experimental measurements show the relationships between output voltage, current, and transferred charge and time under different load or no-load conditions.

[0035] Figure 5 The effect of the spacing between electrodes on output performance is shown.

[0036] Figure 6 A schematic diagram of the DCIC-TENG structure is shown.

[0037] Figure 7 An exploded view of DCIC-TENG is shown.

[0038] Figure 8 The energy harvesting principle of DCIC-TENG is shown.

[0039] Figure 9 A schematic diagram showing the output performance and electric field change rate of the DCIC-TENG is presented.

[0040] Figure 10 The output voltage and current of the DCIC-TENG under different load resistances are shown.

[0041] Figure 11 The relationship between the output power and load resistance of the DCIC-TENG is shown.

[0042] Figure 12 The electrode pair at different frequencies is shown. OC (A), I SC (B) and Q SC (C).

[0043] Figure 13 V is shown OC (A), I SC(B) and Q SC (C) and the relationship with the motion frequency.

[0044] Figure 14 A schematic diagram showing the number of electrode pairs and the number of paired friction pairs with opposite polarity is shown.

[0045] Figure 15 The relationship between the charge transferred per unit time and the motion frequency under different combinations of n and m is shown.

[0046] Figure 16 A circuit diagram of the rectifier circuit is shown.

[0047] Figure 17 The experimental results showing the relationship between the voltage of C L and time under different power regulation circuit conditions are shown.

[0048] Figure 18 DCIC-TENG specific test results are shown.

[0049] Figure 19 DCIC-TENG specific test results are shown.

[0050] Figure 20 DCIC-TENG and CS-TENG comparison results are shown.

[0051] Figure 21 The relationship between the charge of C L and the charge of C a / C b is shown.

[0052] Figure 22 A system architecture diagram is shown.

[0053] Figure 23 The output results of the system are shown.

[0054] Figure 24 A schematic diagram of the existing CF-TENG is shown. DETAILED DESCRIPTION

[0055] The present disclosure will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are intended to be illustrative only and not limiting of the present disclosure. In addition, it should be noted that only the parts related to the present disclosure are shown in the drawings for ease of description.

[0056] It should be noted that the embodiments and features in the embodiments in the present disclosure can be combined with each other without conflict. The technical solutions of the present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0057] Unless otherwise stated, the exemplary implementations / examples illustrated will be understood to provide exemplary features of various details that can be implemented in practice to embody the technological concepts of the present disclosure. Accordingly, features of the various implementations / examples can additionally be combined, separated, interchanged, and / or rearranged, unless otherwise stated, without departing from the technological concepts of the present disclosure.

[0058] The use of cross-hatching and / or shading in the drawings is generally used to illustrate the boundaries, of adjacent components. As such, unless specified, the presence of cross-hatching or shading in a drawing generally shall not be construed to indicate or imply any particular material, material properties, dimensions, proportions, commonality of materials between components, and / or any other characteristic or property of a component, unless otherwise specified. Additionally, in the drawings, the dimensions and relative dimensions of the various components can be exaggerated or rendered for clarity and / or descriptive purposes. Where exemplary embodiments can be implemented differently, a particular process sequence can be performed in an order different than described. For example, two described consecutive processes can be performed at substantially the same time or in the reverse order of the described sequence. Additionally, like reference numerals can denote like components.

[0059] When a component is referred to as being “on” or “over” another component, “connected to” or “coupled to” another component, it can be directly on, directly connected to, or directly coupled to the other component, or one or more intervening components can be present. However, when a component is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another component, there are no intervening components present. To that end, the term “connected” can refer to a physical or electrical connection, whether or not with intervening components.

[0060] For descriptive purposes, the present disclosure can use spatial or relative terms, such as “below,” “lower,” “under,” “underneath,” “below,” “down,” “up,” “above,” “over,” “higher,” and “side” (e.g., as in “sidewall”) to describe the relationship between one component and another component as illustrated in the figures. The spatial or relative terms can be intended to encompass different orientations of the device in use, operation, and / or manufacture in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, a component described as “below” or “under” another component would then be oriented “above” the other component. Thus, the exemplary term “below” can encompass both an orientation of above and below. Moreover, the device can be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatial or relative descriptors used herein interpreted accordingly.

[0061] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, to the extent that the terms "comprising," "including," "containing," and / or "having" and variations thereof are used herein, such terms are intended to be inclusive in a manner similar to the term "comprising" as that term is interpreted when employed as a transitional term in a claim. It is also noted that, as used herein, the terms "substantially," "approximately," and other similar terms are used as synonyms for "about," and are employed to account for inherent variations in measuring, calculating, and / or providing a value or quantity.

[0062] According to embodiments of the present disclosure, a triboelectric generator is provided. In the present disclosure, the triboelectric generator has a constant inherent capacitance. Thus, the triboelectric generator of the present disclosure is a constant intrinsic capacitance triboelectric generator (CIC-TENG).

[0063] As shown in FIG. 1, the triboelectric generator 10 can include triboelectric pairs and electrode pairs. The triboelectric pairs can include a first triboelectric layer 110 and a second triboelectric layer 120. The electrode pairs can include a first electrode 210 and a second electrode 220. Figure 1

[0064] ​The first friction layer 110 and the second friction layer 120 can be oppositely arranged and made of two different materials, or at least the friction surfaces thereof are made of two different materials. In the present disclosure, preferably, the first friction layer 110 and the second friction layer 120 can be made of PET and PVC plastic materials, respectively. The first electrode 210 and the second electrode 220 can be made of metal materials, for example, can be made of Cu thin film. The first electrode 210 and the second electrode 220 can be arranged at intervals. For example, the first electrode 210 and the second electrode 220 can be attached to the surfaces on both sides of the spacer layer 300. For example, in the case of the first electrode 210 and the second electrode 220 being made of Cu thin film, the Cu thin film can be attached to the surfaces on both sides of the acrylic film. In the following, PET, PVC, Cu thin film and acrylic film will be taken as examples for illustration, it should be noted that these materials are only preferred, and not limit the content of the present disclosure, and those skilled in the art can also select other suitable materials. The electrode pair composed of the first electrode 210 and the second electrode 220 can move between the first friction layer 110 and the second friction layer 120, so that the first electrode 210 transfers electric charges with the friction surface of the first friction layer 110, and the second electrode 220 transfers electric charges with the friction surface of the second friction layer 120. In the present disclosure, the moving direction of the electrode pair is referred to as the transverse direction, and the arrangement direction of the electrode pair and the friction pair is referred to as the longitudinal direction. Figure 1 The moving direction of the electrode pair can be referred to as the transverse direction, and the arrangement direction of the electrode pair and the friction pair is referred to as the longitudinal direction.

[0065] In the present disclosure, the moving speed of the electrode pair is constant during the process of the electrode pair entering between the first friction layer 110 and the second friction layer 120 and moving therein. By the transverse movement of the electrode pair attached to the acrylic film in the space between the two friction layers, the kinetic energy can be effectively obtained. According to the present disclosure, the mechanical structure of the CIC-TENG can be more stable, and the compact design provides a larger constant intrinsic capacitance.

[0066] Each power generation cycle of the friction power generation device according to the present disclosure includes four stages, i.e. stage (I), stage (II), stage (III) and stage (IV). In the following, the first friction layer 110 is made of PET, and the second friction layer 120 is made of PVC as an example for illustration.

[0067] Figure 2 The four stages of the power generation cycle of the friction power generation device are shown. Among them, in stage (I), contact electrification occurs at the interface (contact surface) of the first friction layer 110 and the second friction layer 120. As Figure 2In stage (I), due to the contact electrification, the contact surface of the first rubbing layer 110 can be positively charged, while the contact surface of the second rubbing layer 120 can be negatively charged. A certain amount of charge is transferred from the contact surface of the first rubbing layer 110 to the contact surface of the second rubbing layer 120. In stage (II), the electrode pair can be inserted into the space between the first rubbing layer 110 and the second rubbing layer 120 at a constant speed, so that the two closely attached first rubbing layer 110 and second rubbing layer 120 are separated, and a downward quasi-uniform electric field is formed in the space between them. Due to the charge transfer, the average potential of the top first electrode 110 will be higher than that of the bottom second electrode 120, so there is a potential difference between the first electrode 110 and the second electrode 120, which will generate an electromotive force, and in the case that the first electrode 110 and the second electrode 120 are connected to an external circuit (represented by resistance R), an electric current will flow from the first electrode 110 to the second electrode 120. As the electrode pair moves at a constant speed, the potential difference between the first electrode 110 and the second electrode 120 increases until stage (III). In stage (III), the electrode pair can completely overlap the rubbing pair, at which time the potential difference caused by the charge of the rubbing layer will offset the built-in electric field between the two electrodes, and at this time the current in the external circuit is zero. Then in stage (IV), the electrode pair moves away from between the rubbing pair, and the potential difference between the two electrodes caused by the rubbing layer decreases, which will form a reverse current in the external circuit opposite to the current in stage (II). When the electrode pair moves at a constant speed with a constant intrinsic capacitance, the output waveform of the short-circuit circuit (I SC ) of the CIC-TENG is similar to a square wave, while the open-circuit voltage (V OC ) is similar to a triangular wave. Therefore, the open-circuit voltage (V OC ) of the CIC-TENG has a good linear relationship with the electrode displacement, as shown in FIG. Figure 3 In Figure 3 , the relationship between the open-circuit voltage (V OC ) of the CIC-TENG according to the present disclosure and the electrode displacement is shown in green. In the upper left corner of Figure 3 , the relationship between the open-circuit voltage (V OC ) of the sliding mode TENG and the electrode displacement is shown. Those skilled in the art will understand that, compared with the sliding mode TENG, the CIC-TENG can be better applied to a self-powered sensor or an energy providing device to provide electricity.

[0068] In order to clearly illustrate the mechanism and optimization principles of the CIC-TENG of the present disclosure, a mathematical model based on electrokinetics can be established for the CIC-TENG, and can be used to evaluate the performance, etc.

[0069] The length of the first friction layer 110 and the second friction layer 120 is L, and the length of the first electrode 110 and the second electrode 120 is L. The moving speed of the electrode pair is v, the surface area of the first electrode 110 and the second electrode 120 is S, and the distance between the first electrode 110 and the second electrode 120 is d. Thus, the intrinsic capacitance of the CIC-TENG can be expressed as wherein ε0 is the vacuum permittivity, ε r is the relative permittivity. Since the distance d and the surface area S are constant, the intrinsic capacitance is constant. In the present disclosure, the relative positions of the first electrode 110 and the second electrode 120 are set to be relatively fixed.

[0070] At the time t = 0, the electrode pair starts to insert between the friction pair. At the time t = T (wherein ), the electrode pair completely overlaps with the friction pair. At the time t = 2T, the electrode pair completely leaves the friction pair.

[0071] When 0≤t≤T, the electrode pair inserts between the first friction layer 110 and the second friction layer 120 and moves at a constant speed. The electromotive force in the circuit caused by the electric field of the charges (whose surface charge density is expressed as σ) of the friction surfaces of the first friction layer 110 and the second friction layer 120 linearly increases. The charge Q of the capacitance changes over time, which can be expressed as:

[0072]

[0073] wherein R is the load resistance of the external circuit, At is the linearly increasing electromotive force, is the coefficient of the linearly increasing electromotive force.

[0074] Using the initial condition Q(t = 0) = 0, the solution of the differential equation of formula 1 is:

[0075]

[0076] The output current can be expressed as:

[0077]

[0078] Similarly, when T≤t≤2T, the electrode pair is in the process of leaving the friction pair, and the charge Q of the capacitance changes over time, which can be expressed as:

[0079]

[0080] Considering the continuity of the charge Q at the time t = T, it can be obtained that:

[0081]

[0082] The output current can be expressed as:

[0083]

[0084] At the moment t = T, the output current can reach the current maximum I max i.e.

[0085]

[0086] The maximum short-circuit current I short of the CIC-TENG corresponds to I max when R → 0, i.e.

[0087]

[0088] The open-circuit voltage V OC of the CIC-TENG corresponds to the voltage drop of the load when R → ∞, i.e.

[0089]

[0090] The maximum value of the open-circuit voltage V OC is:

[0091] The maximum output power is:

[0092] In order to make P max reach its maximum value, the extreme condition is:

[0093]

[0094] Therefore,

[0095] Solving this equation gives: i.e.

[0096] The average output power of the CIC-TENG is: i.e. Let then Thus we get When the maximum value of appears, i.e. The maximum value of P * is Therefore, the maximum average output power can be obtained as:

[0097] The FOM material is set as 2 ; So where FOM device represents the upper limit of the average output power of the device, which can be used to evaluate whether the potential of the device meets the requirement. FOM material represents the influence of material selection on the output performance of the CIC-TENG. FOM structure represents the influence of geometric design on the output performance.

[0098] Through the above calculation, the analytical expressions of the output voltage, current and transferred charge are obtained. In order to facilitate the design of CIC-TENG, we numerically simulate the CIC-TENG based on the model, which clearly illustrates the relationship between the output parameters and the design parameters. Figure 4 Figures 2A to 2C respectively show the numerical simulation and experimental measurement relationship between the output voltage, current and transferred charge and time under different load or no load conditions.

[0099] In addition, the influence of the distance between the electrodes on the output performance is shown in Figure 5 , where Figure 5 Figure 2A shows the relationship between the open circuit voltage (V OC ) and the distance, Figure 2B shows the relationship between the short circuit current (I SC ) and the distance, and Figure 2C shows the relationship between the transferred charge (Q SC ) and the distance. As can be seen from Figure 2A, the larger the distance, the higher the output voltage, and the output voltage is saturated rapidly after a distance of 2 mm.

[0100] The load impedance also has an influence on the output performance. In both load and no load conditions, the voltage curve is similar to a periodic triangular wave. The short circuit current waveform is a square wave in the short circuit condition, and is similar to a triangular wave in the load condition. The waveform of the transferred charge is also different in the two conditions. In the short circuit condition, the waveform of the transferred charge is a triangular wave, and in the load condition, the waveform of the transferred charge tends to be smooth, which is approximately a sine wave.

[0101] In addition to the load impedance, other factors also affect the output of the CIC-TENG, such as the selection of the friction material. In the present disclosure, a combination of PVC and PET is used to increase the surface charge density of the friction layer, thereby improving the charge transfer efficiency and the output of the CIC-TENG.

[0102] According to a further embodiment of the present disclosure, a CIC-TENG in the form of a disc is provided. This form of CIC-TENG can continuously acquire unidirectional mechanical energy from the environment and is suitable for various scenarios.

[0103] The disc-shaped CIC-TENG in the form of a disc (referred to as DCIC-TENG) is generally used to continuously acquire unidirectional mechanical energy from the environment and is suitable for various scenarios. Figure 6The DCIC-TENG is shown, consisting of a first friction layer, a second friction layer, a first electrode, a second electrode, and a rotating shaft. Figure 6 In the DCIC-TENG shown, the first friction layer 110 can be made of PET material, the second friction layer 120 can be made of PVC material, the first electrode 210 is formed of a Cu film, and the second electrode 220 is formed of a Cu film. The Cu film is attached to the acrylic film to form an electrode pair. The entire disk can be uniformly divided into multiple regions, for example, an even number of regions (e.g., 2m). Each region is provided with one friction pair (including a first friction layer and a second friction layer respectively). In adjacent friction pairs, the first and second friction layers are arranged in opposite positions to have opposite polarities. For example, in one friction pair, the first friction layer is located on top and the second friction layer is located on the bottom, while in an adjacent friction pair, the first friction layer is located on the bottom and the second friction layer is located on top. Multiple friction pairs are arranged in a ring to form the DCIC-TENG. That is, friction pairs with different polarities are provided in adjacent regions, and the two friction layers of adjacent friction pairs are reversed. The first and second electrodes attached to the acrylic film are connected to the friction pairs via a rotating shaft. Figure 7 An exploded view of DCIC-TENG is shown. Figure 8 The image shows a photograph of DCIC-TENG.

[0104] The energy harvesting principle of DCIC-TENG is as follows: Figure 8 The diagram illustrates an example of several friction pairs and a pair of electrodes. In stage (I), contact charging is formed at the interface between a first friction layer 110 and a second friction pair 120 made of different triboelectric materials. The first electrode 210 and the second electrode 220 enter the friction pair at a constant velocity, causing the tightly adhered first friction layer 110 and the second friction layer 120 to separate, creating a quasi-uniform electric field between them. In stage (II), the electrode pair is inserted into the first friction pair, generating an electromotive force (EMF) that increases linearly between the first friction pair. In stage (III), the EMF reaches its maximum value when the electrode pair completely overlaps with the first friction pair. In stage (IV), the EMF gradually decreases as the electrodes continue to move forward and insert into the second friction pair, reaching zero when half the length of the electrode pair is inserted into the second friction pair. The EMF then reverses direction, reaching its maximum value in stage (V) when the electrode pair just completely overlaps with the second friction pair. Then, the electrode pair is inserted into a third friction pair with the same polarity as the first friction pair, and the electromotive force begins to gradually decrease. When half the length of the electrode is inserted into the third friction pair, the electromotive force is zero. The above stages are repeated.

[0105] This structural design doubles the output performance of the DCIC-TENG and doubles the rate of change of the electric field (e.g.,Figure 9 (As shown). In other words, the coefficient A in formulas 5, 6, and 9 becomes 2A. One A originates from the decrease (or increase) in the electric field generated by the first friction pair, and the other A originates from the increase (or decrease) in the electric field generated by the second friction pair. Therefore, V OC I SC and Q SC All will double. The DCIC-TENG has 3 electrode pairs and 6 friction pairs. At a motion frequency of 3.6Hz, the output voltage and current under different load resistances are as follows: Figure 10 As shown, the relationship between output power and load resistance is as follows: Figure 11 As shown, when the load resistance is 55MΩ, the highest instantaneous output power is 0.3mW, and the power density is 33.3mW / m². 2 . Figure 12 The electrode pair at different frequencies is shown. OC (A), I SC (B) and Q SC (C).

[0106] The periodic rotation frequency, the number of electrodes, and the number of friction pairs all affect the output performance of the DCIC-TENG. Based on the established analytical model, the relationship between the output parameters and the motion frequency was obtained. OC (A), I SC (B) and Q SC (C) The relationship with motion frequency is as follows: Figure 13 As shown, the simulation results agree well with the experimental results under both ideal and loaded conditions. Let n represent the number of electrode pairs, and m represent the number of pairs of friction pairs with opposite polarities. The sector radii for each electrode and friction pair are π / n and π / m, respectively. Wherein... Figure 14 The diagram shows the number of electrode pairs and the number of pairs of friction pairs with opposite polarities.

[0107] Figure 15 The relationship between the charge transferred per unit time and the motion frequency is shown under different combinations of n and m, denoted as (n, m). The total charge transferred per rotation cycle (rotation angle 2π) is denoted as Q, and the charge transfer contribution from each electrode pair is denoted as Q1. Since the electrode pairs are parallel, Q = nQ1. When n > m, the radian of each electrode sector is less than the radian of each friction pair. Therefore, during the periodic motion of the electrode pairs, there is only a short period where the electrode pairs completely overlap with the friction pairs, and the electromotive force between the two electrodes is zero. In this case, a certain amount of time is wasted in each cycle of each electrode pair, and Q1 is reduced by a factor of m / n. When n > m, This is essentially the same as the case where n = m (Q = mQ1) utilizes the entire cycle; therefore, when m is a fixed value, n greater than m does not provide a significant advantage for a larger Q. For simplicity, when n ≥ m, n is preferably equal to m. When n is less than m, the radius of the sector for each electrode pair is greater than the radius of the sector for each friction pair. For each electrode pair in the motion cycle, there will be a period of time during which each pair of electrodes simultaneously enters and leaves a friction pair with different polarities. In this case, the potential difference between the electrodes hardly changes, and the transferred charge tends to zero. Therefore, Q'1 = ηQ1, where η represents the time of the motion cycle when the electrodes enter and leave two friction pairs with different polarities. If So Where 0 ≤ η ≤ 1. If So Where 0 ≤ η ≤ 1. Therefore, when n < m, Q = nQ'1 = nηQ1 ≤ nQ1 < mQ1. Therefore, the total charge transfer efficiency is highest when the number of electrode pairs is equal to the number of pairs of friction pairs with opposite polarities (n = m).

[0108] Figure 15 Figure A shows the effect of n on Q when m is 2. Figure 15 Figure B shows the effect of m on Q when n is 2. When n is set equal to m, under ideal conditions where the effect of the RC delay of the load circuit is negligible, Q will increase linearly with increasing n, as shown below. Figure 15 As shown in C. However, in practice, the RC delay cannot be ignored. When n is too large, the time for each electrode pair to pass through the friction pair may be too short to achieve effective charge transfer and thus reduce Q. In practical load circuits, Q only reaches its maximum value with a suitable n (or m).

[0109] To verify the advantages of the CIC-TENG, we used it as a power source to charge capacitors and evaluated its charging performance. Three commonly used power regulation circuits were employed: a half-wave rectifier circuit, a full-wave rectifier circuit, and a Bennet rectifier circuit, as shown below. Figure 16 Figures A through C are shown. The target capacitor being charged is denoted as C. L The inherent capacitance is represented by C. in C under three different power regulation circuits L The experimental results of the relationship between voltage and time are as follows: Figure 17 As shown (the amplitude of the equivalent voltage source is V0 = 10V, C...), in =1nF,C L =2μF), among which the rectifier circuit has the best effect and the highest power transfer efficiency.

[0110] When the DCIC-TENG rotates at a frequency of 3.6Hz, a full-wave rectifier circuit is used to convert the 100μF C L It only takes about 160 seconds to charge to 8V, such as Figure 18 As shown. Due to the inherent capacitance (C) of the DCIC-TENG. in ) is much smaller than C L Although a full-wave rectifier circuit consumes more energy in the rectifier bridge, it can still obtain energy for both half-cycles compared to a half-wave rectifier circuit. Within a certain time period, C... L The charge and C L It depends on the size, such as Figure 19 As shown. Figure 20 Comparison of reservations for C in C of DCIC-TENG L The charge and in the same C in The best results were obtained from the CS-TENG. The DCIC-TENG has twice the power transfer efficiency of the CS-TENG. The C of the CS-TENG... in From the variable part (C) a ) and constant part (C b Composed of ) C L The charge and C a / C b The relationship between charges is as follows Figure 21 As shown. To demonstrate the application of DCIC-TENG, the inventors created a real-time anemometer based on DCIC-TENG. DCIC-TENG is connected to an anemometer cup, which uses the kinetic energy of the wind to rotate DCIC-TENG, as shown. Figure 22 As shown. The output voltage of the DCIC-TENG is transmitted to a computer terminal in real time for processing to display the wind speed. The output voltage and the processed real-time wind speed are shown below. Figure 23 As shown.

[0111] According to the technical solution disclosed herein, compared with existing methods, it can effectively achieve the matching of mechanical motion frequency and circuit characteristics, and can significantly improve the output performance of the TENG. For example, in the existing CF-TENG (contact-mode freestanding–triboelectric-layer based TENG) (refer to...) Figure 24 The CF-TENG consists of a pair of electrodes, with a triboelectric layer that moves vertically between them, but the range of movement is limited. The dielectric of the CF-TENG's inherent capacitance is a combination of air and the triboelectric layer. Therefore, the inherent capacitance is very small, resulting in a large range of motion, and requiring a relatively large load resistance R to well match the similar mechanical movement frequency, sacrificing reduced output current. The small range of motion reduces charge transfer efficiency, limiting application scenarios.

[0112] The present disclosure provides a new constant intrinsic capacitance TENG structure, which is easy to manufacture and facilitates matching of mechanical motion frequency and circuit characteristic frequency. Analytical expressions of key output parameters of CIC-TENG and conditions for achieving maximum output power are analyzed to provide guidance for optimization of material selection, geometric design, etc. The output voltage, current and transferred charge under no-load and load conditions are measured by numerical simulation and experiment, and both are in good agreement. In order to collect energy more effectively when possible, a CIC-TENG in the form of a disc is proposed, and the maximum output power density can reach 33 MW / m 2 .

[0113] In the description of the present specification, the description of the terms "one embodiment / way", "some embodiments / ways", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment / way or example are included in at least one embodiment / way or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment / way or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments / ways or examples. In addition, the person skilled in the art can combine and combine the different embodiments / ways or examples described in the present specification and the features of the different embodiments / ways or examples without contradiction.

[0114] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0115] Those skilled in the art should understand that the above embodiments are only for the purpose of clearly illustrating the present disclosure, and are not intended to limit the scope of the present disclosure. Based on the above disclosure, other changes or modifications can also be made by those skilled in the art, and these changes or modifications are still within the scope of the present disclosure.

Claims

1. A triboelectric power generation device with a constant inherent capacitance, characterized in that, include: A friction pair includes a first friction layer and a second friction layer disposed opposite to each other, the first friction layer and the second friction layer being made of different materials and capable of carrying opposite charges; as well as The electrode pair includes a first electrode and a second electrode, which are isolated from each other and are movable between a first friction layer and a second friction layer. The first electrode and the second electrode are arranged longitudinally opposite each other, and the relative position and surface area of ​​the first electrode and the second electrode are fixed. The electrode pair formed by the first electrode and the second electrode can move laterally at a constant speed in the space between the first friction layer and the second friction layer arranged longitudinally opposite each other so as to enter and exit. The first electrode is in contact with the first friction layer, and the second electrode is in contact with the second friction layer.

2. The triboelectric power generation device as described in claim 1, characterized in that, The contact surface of the first friction layer has the same shape and / or size as the contact surface of the first electrode, and the contact surface of the second friction layer has the same shape and / or size as the contact surface of the second electrode.

3. The triboelectric power generation device as described in claim 1, characterized in that, The first friction layer and the second friction layer are made of PET or PVC, respectively, and / or the first electrode and the second electrode are made of Cu thin film.

4. The triboelectric power generation device as described in claim 1, characterized in that, Each power generation cycle of the triboelectric power generation device includes: (1) Contact charging occurs at the contact surface of the first friction layer and the second friction layer, and the electrode pair is inserted into the space between the first friction layer and the second friction layer at the constant speed, so that the two tightly attached layers are separated, thereby forming a quasi-uniform electric field between them. (2) The electrode pair moves at the constant speed in the space between the first friction layer and the second friction layer, and the current flows from one of the first electrode and the second electrode to the other electrode; (3) When the electrode pair reaches the overlap position where it completely overlaps with the contact surfaces of the first and second friction layers, the current is zero; and (4) The electrode pair leaves the friction pair from the overlapping position at the constant speed, and the current flows from the other electrode to the first electrode.

5. The triboelectric power generation device as described in any one of claims 1 to 3, characterized in that, The number of friction pairs is multiple, and the number of electrode pairs is more than one. The friction pairs and electrode pairs constitute a disk-shaped triboelectric power generation device. The friction pairs and electrode pairs are configured to rotate relative to each other so that the electrode pairs leave or enter the space between the first and second friction layers of each friction pair.

6. The triboelectric power generation device as described in claim 5, characterized in that, In the disc-shaped triboelectric generator, each pair of adjacent friction pairs has opposite polarities.

7. The triboelectric power generation device as described in claim 6, characterized in that, The number of friction pairs is m, and the number of electrode pairs is n, where m = n > 1.

8. The triboelectric power generation device as described in claim 7, characterized in that, The disk is evenly divided into 2m regions, and each region is provided with a friction pair.

9. The triboelectric power generation device as described in claim 5, characterized in that, Each power generation cycle of the triboelectric power generation device includes: (1) Contact charging occurs at the contact surface of the first friction layer and the second friction layer, and the electrode pair is inserted into the space between the first friction pair at the constant speed; (2) The electrode pair moves at the constant speed in the space between the first friction pair, and the electromotive force increases linearly; (3) The contact surfaces of the electrode pair and the first friction pair completely overlap, and the electromotive force reaches its maximum value; (4) The electrode pair continues to move at the constant speed and inserts into the second friction pair. The electromotive force gradually decreases. When half the length of the electrode pair is inserted into the second friction pair, the electromotive force is zero. (5) The electrode pair continues to move at the constant speed, and the electromotive force reaches its maximum value when the contact surfaces of the electrode pair and the second friction pair are completely overlapped. (6) The electrode pair continues to move at the constant speed, and the electromotive force repeats (1) to (5).

10. A self-powered sensor, characterized in that, The triboelectric power generation device as described in any one of claims 1 to 9 is included to provide electrical power to the sensor.

11. An energy supply device, characterized in that... Includes a triboelectric power generation device as described in any one of claims 1 to 9 for providing energy.

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