A multifunctional tribo-nano cantilever energy harvesting device and system

Abstract

The present invention discloses a multifunctional triboelectric nanocantilever energy harvesting device and system, which relates to the field of triboelectric nanocantilever energy harvesting. The device mainly includes: a base, a support assembly, a sliding friction unit and a sliding assembly; the sliding friction unit includes a cathode member and an anode member; the support assembly includes a fixed seat, a beam and a fixed frame; one end of the beam is connected to the base through the fixed seat, and the other end is connected to the center of the cathode member through the fixed frame. The anode member is connected to the base through the sliding assembly, and the sliding assembly is used to move the anode member along the length direction, width direction and height direction of the base; the sliding friction unit is used to connect a voltage sensor; the voltage sensor is used for the output voltage of the sliding friction unit; the output voltage is used to determine the health state of the beam. The present invention can not only make the pre-tightening force between the two friction layers adjustable, but also can simply monitor the health state of the cantilever beam.

Description

Technical Field

[0001] The present invention relates to the field of triboelectric nanocantilever energy harvesting, and particularly to a multifunctional triboelectric nanocantilever energy harvesting device and system. Background Art

[0002] With the rapid development of the Internet of Things and the continuous development of intelligent electronic technologies such as wireless sensor networks, energy harvesting technology has attracted increasing attention to meet the growing power supply requirements of low-power sensors. So far, batteries are still the choice for powering wireless sensor networks, but they have some obvious disadvantages, such as limited lifespan, the need for regular replacement, and environmental pollution. Therefore, researchers are committed to developing clean and environmentally friendly energy harvesting technologies. As an emerging energy harvesting technology, the triboelectric nanogenerator (TENG) utilizes the principle of triboelectrification to collect scattered energy from the environment and convert it into usable electrical energy, providing a solution to extend the battery lifespan and even replace batteries to power wireless sensor networks sustainably, which has attracted great interest.

[0003] For large-scale deployed wireless sensor networks, in order to meet their power supply requirements, it is also necessary to deploy energy harvesting devices for collecting environmental energy on a large scale. Since the cantilever beam type energy harvesting device has a simple structure and is relatively easy to fabricate, most researchers use it to collect energy from the environment. On the one hand, when researchers deploy triboelectric nanocantilever energy harvesting devices, they often neglect the pre-tightening force between the two friction layers and only design based on experience. However, the pre-tightening force between the two friction layers has a great influence on the output performance of the TENG. When the pre-tightening force is large, the frictional force between the two friction layers is large, resulting in the triboelectric nanocantilever energy harvesting device being unable to collect energy from the environment under weak excitation and the output performance decreasing. When the pre-tightening force is small, although the triboelectric nanocantilever energy harvesting device can collect energy from a weak excitation environment, due to the small contact area between the two friction layers, the output performance of the TENG also decreases. Therefore, an appropriate pre-tightening force plays an important role in improving the output performance of the TENG. On the other hand, during the daily operation of the triboelectric nanocantilever energy harvesting device, especially in the stress concentration area, crack damage is inevitable (as shown in Figure 1 ). Stress concentration and damage propagation may cause the triboelectric nanocantilever energy harvesting device to malfunction.

[0004] In order to supply energy to the wireless sensor network more reliably and stably, the health monitoring of the triboelectric nanocantilever energy harvesting device is also necessary. At present, the main methods for the health monitoring of the triboelectric nanocantilever energy harvesting device are piezoelectric methods. This method processes the electrical signals generated by the triboelectric nanocantilever energy harvesting device through numerical analysis, intelligent algorithms, etc., so as to obtain the vibration parameters (frequency, voltage, etc.) of the cantilever beam, and then judge the health state of the cantilever beam. However, the piezoelectric measurement method requires a certain thickness of piezoelectric material to be coated above or below the cantilever beam, which inevitably changes the vibration characteristics of the original cantilever beam, making the triboelectric nanocantilever energy harvesting device unable to couple well with the natural environment, resulting in a decline in the output performance of the triboelectric nanocantilever energy harvesting device, and the calculation process is complex. In view of the above two aspects, it is necessary to study a cantilever energy harvesting device with adjustable pre-tightening force between two friction layers and capable of simply monitoring the health of the cantilever beam. Summary of the Invention

[0005] The purpose of the present invention is to provide a multifunctional triboelectric nanocantilever energy harvesting device, which can not only adjust the pre-tightening force between two friction layers, but also simply monitor the health state of the cantilever beam.

[0006] To achieve the above purpose, the present invention provides the following solutions:

[0007] A multifunctional triboelectric nanocantilever energy harvesting device, comprising: a base, a support assembly, a sliding friction unit, and two identical sliding assemblies;

[0008] The sliding friction unit includes a cathode member and two identical anode members; the cathode member is used for triboelectrification with the anode members in the horizontal direction;

[0009] The support assembly includes a fixed seat, a cover plate, a beam, and a fixed frame; one end of the beam is connected to the base through the fixed seat and the cover plate, and the other end of the beam is connected to the center of the cathode member through the fixed frame, and the beam is parallel to the base;

[0010] One of the anode members is connected to the base through one of the sliding assemblies, and the other anode member is connected to the base through the other sliding assembly; one of the anode members and the other anode member are on the same horizontal line, and one of the anode members and the other anode member do not contact;

[0011] The sliding assembly includes a first slide rail mounted on the base, a second slide rail mounted on the first slide rail, and a third slide rail mounted on the second slide rail; the anode member is mounted on the third slide rail; the first slide rail is used to move the anode member along the length direction of the base, the second slide rail is used to move the anode member along the width direction of the base, and the third slide rail is used to move the anode member along the height direction of the base;

[0012] The sliding friction unit is used to connect to a voltage sensor; the voltage sensor is used to obtain the output voltage of the sliding friction unit; the output voltage is used to determine the health state of the beam.

[0013] Optionally, the fixed seat is a gantry frame; one end of the fixed seat is mounted on the base by bolts, and the fixed seat is perpendicular to the base;

[0014] One end of the beam is placed on the other end of the fixed seat and one end of the beam is fixed to the other end of the fixed seat by a cover plate.

[0015] Optionally, the cathode member is of a circular structure; a connection block is provided at the center of the cathode member; the other end of the beam is mounted on the connection block through a fixing frame.

[0016] Optionally, the cathode member is a moving plate coated with a friction cathode material; the anode member is a moving plate coated with a friction anode material.

[0017] Optionally, the friction cathode material is Teflon; the friction anode material is copper.

[0018] Optionally, the output voltage is used to determine the health state of the beam according to the fact that the output voltage has a proportional linear relationship with the movement height of the cathode member.

[0019] A multifunctional triboelectric nanocantilever energy harvesting system includes a processor, a voltage sensor, and a multifunctional triboelectric nanocantilever energy harvesting device;

[0020] The voltage sensor is connected to the sliding friction unit; the voltage sensor is used to obtain the output voltage of the sliding friction unit;

[0021] The processor is connected to the voltage sensor; the processor is used to determine the health state of the beam according to the output voltage.

[0022] Optionally, in terms of determining the health state of the beam according to the output voltage, the processor is used for:

[0023] Determine the moving height of the cathode member based on the output voltage and based on the fact that the output voltage has a proportional linear relationship with the moving height of the cathode member;

[0024] Determine the health state of the beam based on the moving height of the cathode member;

[0025] Wherein, when the maximum value of the moving height of the cathode is greater than a set threshold, it is determined that there is a defect in the beam.

[0026] According to the specific embodiments provided by the present invention, the following technical effects are disclosed by the present invention:

[0027] The present invention is provided with a first slide rail, a second slide rail and a third slide rail; the first slide rail is used to move the anode member along the length direction of the base, the second slide rail is used to move the anode member along the width direction of the base, and the third slide rail is used to move the anode member along the height direction of the base, that is, the present invention realizes the spatial movement of the anode member through three slide rails, so that the pre-tightening force between the anode member and the cathode member can be adjusted; the present invention judges the health state of the beam through the output voltage of the sliding friction unit, without other devices or materials, avoiding reducing the output performance of the friction nanocantilever energy harvesting device. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is a defect diagram of the beam in the existing friction nanocantilever energy harvesting device;

[0030] Figure 2 It is a structural diagram of the multifunctional friction nanocantilever energy harvesting device of the present invention;

[0031] Figure 3 It is a friction power generation working principle diagram of the multifunctional friction nanocantilever energy harvesting device of the present invention;

[0032] Figure 4 It is a defect detection principle diagram of the beam in the multifunctional friction nanocantilever energy harvesting device of the present invention;

[0033] Figure 5 It is a structural diagram of the multifunctional friction nanocantilever energy harvesting system of the present invention. Detailed Embodiments

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] To make the above objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] As Figure 2 shown, the embodiment of the present invention provides a multifunctional triboelectric nanocantilever energy harvesting device, including: a base 4, a support assembly, a sliding friction unit, and two identical sliding assemblies.

[0037] The sliding friction unit includes a cathode member 5 and two identical anode members; the cathode member 5 is used for triboelectrification with the anode members in the horizontal direction; Figure 2 Only the left anode member 6 is shown in the figure, and the right anode member is the same as the left anode member 6. Among them, the cathode member 5 is a moving plate coated with a triboelectric cathode material; the anode member is a moving plate coated with a triboelectric anode material. Preferably, the triboelectric cathode material is Teflon; the triboelectric anode material is copper. Further, each anode member is divided into upper and lower parts, and both parts are coated with the triboelectric anode material copper.

[0038] In addition, both the cathode member 5 and the anode members are coated with a nickel cloth material. Since the nickel cloth has adhesiveness on both sides, the triboelectric cathode material and the triboelectric anode material are respectively fixed on the cathode member 5 and the anode members.

[0039] The support assembly includes a fixed seat 7, a cover plate 10, a beam 8, and a fixed frame 9; one end of the beam 8 is connected to the base 4 through the fixed seat 7 and the cover plate 10, and the other end of the beam 8 is connected to the center of the cathode member 5 through the fixed frame 9 and a connecting block 11, and the beam 8 is parallel to the base 4.

[0040] Further, the fixed seat 7 is a gantry frame; one end of the fixed seat 7 is installed on the base 4 through bolts, and the fixed seat 7 is perpendicular to the base 4; one end of the beam 8 is placed on the other end of the fixed seat 7 and one end of the beam 8 is fixed on the other end of the fixed seat 7 through the cooperation of the cover plate 10 and bolts.

[0041] In one example, the cathode member 5 is of a circular structure; the connecting block 11 is arranged at the center of the cathode member 5, that is, the connecting block 11 is installed at the center of the cathode member 5 through bolts; the other end of the beam 8 is installed on the connecting block 11 through the fixed frame 10.

[0042] One of the anode components is connected to the base through one of the sliding components, and the other anode component is connected to the base through the other sliding component; one of the anode components and the other anode component are on the same horizontal line, and one of the anode components and the other anode component do not touch each other.

[0043] The sliding component includes a first slide rail 1 installed on the base, a second slide rail 2 installed on the first slide rail 1, and a third slide rail 3 installed on the second slide rail 2; the anode component is installed on the third slide rail 3; the first slide rail 1 is used to move the anode component along the length direction of the base, the second slide rail 2 is used to move the anode component along the width direction of the base, and the third slide rail 3 is used to move the anode component along the height direction of the base. Therefore, the pre-tightening force between the anode component and the cathode component can be adjusted by three slide rails.

[0044] The sliding friction unit is used to connect a voltage sensor; the voltage sensor is used to obtain the output voltage of the sliding friction unit; the output voltage is used to determine the health state of the beam.

[0045] Further, the output voltage is used to determine the health state of the beam according to the fact that the output voltage and the movement height of the cathode component are in a positive proportional linear relationship.

[0046] The working principle of the sliding friction unit is as Figure 3 shown. At the initial position, the cathode component and the left anode component completely overlap. Since the electron gain and loss abilities of the friction materials of the two are different, negative charges accumulate on the surface of the cathode component, and an equal amount of positive charges accumulate on the surface of the left anode component. Then, when the cathode component slides to the right, due to the electrostatic induction effect, the positive charges in the circuit will flow from the left anode component to the right anode component through the load. When the cathode component and the right anode component completely overlap, all the positive charges will flow into the right anode component. Subsequently, the cathode component moves in the opposite direction, and at this time the moving direction of the positive charges is the same as its moving direction. Therefore, in an external vibration environment, the beam drives the cathode component to swing up and down. At this time, the upper and lower friction anode materials on the third slide rail are connected to the load with wires, and there will be current flowing through the load.

[0047] Assume that the charge density on the surfaces of the cathode component and the anode component is σ (determined by factors such as material properties and the pre-tightening force between the cathode component and the anode component), the amount of charge flowing through the external load is Q, the equivalent capacitance between the two friction materials is C, and the surface area of the two friction materials is S. Therefore, the output voltage V of the sliding friction unit can be calculated by the following formula:

[0048]

[0049] Under an external excitation, the triboelectric nanocantilever energy harvesting device vibrates, and its working schematic diagram is as shown in Figure 4 Figure. Assume that under a certain excitation, the cathode member rises by H relative to its initial position, and the circular radius of the cathode member is r. Therefore, the area ΔS of the cathode member's change relative to its initial position can be calculated by Equation (2):

[0050]

[0051] where θ can be calculated by Equation (3):

[0052]

[0053] According to Equations (1), (2), and (3), it can be seen that the output voltage V of the sliding friction unit is linearly related to the height H that the cathode member rises. Therefore, by measuring multiple sets of output voltages V and the height H that the cathode member rises through an excitation device, the functional relationship between the output voltage V of the triboelectric nanocantilever energy harvesting device and the height H that the cathode member rises can be obtained. Under a certain known excitation (measured by a sensor), when the output voltage V of the sliding friction unit is obtained, the height H that the cathode member rises at this time can be obtained. If, under a certain known excitation, the output voltage of the sliding friction unit increases for the cantilever beam, then the height that the cathode member rises increases, and thus it can be known that there must be a defect in the cantilever beam at this time (because when there is a defect in the cantilever beam, its own stiffness decreases, and under the same excitation, the height that the moving plate rises increases).

[0054] The present invention also provides a multifunctional triboelectric nanocantilever energy harvesting system, as shown in Figure 5 Figure, which includes a processor, a voltage sensor, and a multifunctional triboelectric nanocantilever energy harvesting device as described in Embodiment 1.

[0055] The voltage sensor is connected to the sliding friction unit; the voltage sensor is used to obtain the output voltage of the sliding friction unit; the processor is connected to the voltage sensor; the processor is used to determine the health state of the beam according to the output voltage.

[0056] Further, in terms of determining the health state of the beam according to the output voltage, the processor is used to:

[0057] Determine the movement height of the cathode member according to the output voltage and according to the fact that the output voltage is in a direct proportional linear relationship with the movement height of the cathode member.

[0058] Determine the health state of the beam according to the movement height of the cathode member.

[0059] Among them, when the maximum value of the movement height of the cathode is greater than a set threshold, it is determined that there is a defect in the beam.

[0060] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.

[0061] Specific examples are used in this article to elaborate on the principles and implementation manners of the present invention. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A multifunctional triboelectric nanocantilever energy harvesting device, characterized in that, it includes: a base, a support assembly, a sliding friction unit, and two identical sliding assemblies; the sliding friction unit includes a cathode member and two identical anode members; the cathode member is used for triboelectrification with the anode member in the horizontal direction; the support assembly includes a fixed seat, a cover plate, a beam, and a fixed frame; one end of the beam is connected to the base through the fixed seat and the cover plate, and the other end of the beam is connected to the center of the cathode member through the fixed frame, and the beam is parallel to the base; one of the anode members is connected to the base through one of the sliding assemblies, and the other anode member is connected to the base through the other sliding assembly; one of the anode members and the other anode member are on the same horizontal line, and one of the anode members and the other anode member do not contact; the sliding assembly includes a first slide rail installed on the base, a second slide rail installed on the first slide rail, and a third slide rail installed on the second slide rail; the anode member is installed on the third slide rail; the first slide rail is used to move the anode member along the length direction of the base, the second slide rail is used to move the anode member along the width direction of the base, and the third slide rail is used to move the anode member along the height direction of the base; the sliding friction unit is used to connect a voltage sensor; the voltage sensor is used to obtain the output voltage of the sliding friction unit; the output voltage is used to determine the health state of the beam.

2. The multifunctional triboelectric nanocantilever energy harvesting device according to claim 1, characterized in that, the fixed seat is a gantry frame; one end of the fixed seat is installed on the base through bolts, and the fixed seat is perpendicular to the base; one end of the beam is placed on the other end of the fixed seat and one end of the beam is fixed to the other end of the fixed seat through the cover plate.

3. The multifunctional triboelectric nanocantilever energy harvesting device according to claim 1, characterized in that, the cathode member is of a circular structure; a connecting block is arranged at the center of the cathode member; the other end of the beam is installed on the connecting block through a fixed frame.

4. The multifunctional triboelectric nanocantilever energy harvesting device according to claim 1, characterized in that, the cathode member is a moving plate coated with a triboelectric cathode material; the anode member is a moving plate coated with a triboelectric anode material.

5. The multifunctional triboelectric nanocantilever energy harvesting device according to claim 4, characterized in that, the triboelectric cathode material is Teflon; the triboelectric anode material is copper.

6. The multifunctional triboelectric nanocantilever energy harvesting device according to claim 1, characterized in that, the output voltage is used to determine the health state of the beam according to the proportional linear relationship between the output voltage and the movement height of the cathode member.

7. A multifunctional triboelectric nanocantilever energy harvesting system, characterized in that, it includes a processor, a voltage sensor, and a multifunctional triboelectric nanocantilever energy harvesting device according to any one of claims 1-6; The voltage sensor is connected to the sliding friction unit; the voltage sensor is used to obtain the output voltage of the sliding friction unit; The processor is connected to the voltage sensor; the processor is used to determine the health state of the beam according to the output voltage.

8. A multifunctional triboelectric nanocantilever energy harvesting system according to claim 7, characterized in that in terms of determining the health state of the beam according to the output voltage, the processor is used for: determining the movement height of the cathode member according to the output voltage and according to the fact that the output voltage has a positive proportional linear relationship with the movement height of the cathode member; determining the health state of the beam according to the movement height of the cathode member; wherein, when the maximum value of the movement height of the cathode is greater than a set threshold, it is determined that the beam has a defect.

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