A dual-helmholtz resonator device based on a triboelectric nanogenerator
By using a dual Helmholtz resonant cavity device based on a triboelectric nanogenerator, and employing a symmetrical design and a porous structure, the problem of inflexible adjustment of the resonant frequency of the Helmholtz resonant structure was solved, and broadband acoustic response and stable acoustic energy acquisition were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DALIAN MARITIME UNIVERSITY
- Filing Date
- 2023-08-24
- Publication Date
- 2026-07-21
AI Technical Summary
The existing Helmholtz resonant structure has inflexible resonant frequency adjustment, resulting in weak performance of sound energy acquisition devices when processing the entire spectrum, and it is prone to sound reflection and echo.
A dual Helmholtz resonant cavity device based on triboelectric nanogenerators is used to achieve a wideband acoustic response through symmetrical design and porous structure, combined with taper adjustment of the conical neck.
It achieves stable acoustic energy acquisition and wideband response, reduces acoustic interference, and improves the flexibility and efficiency of acoustic energy acquisition.
Smart Images
Figure CN117231449B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of acoustic energy harvesting technology, and more particularly to a dual Helmholtz resonant cavity device based on a triboelectric nanogenerator. Background Technology
[0002] In the era of the Internet of Things (IoT), there is an urgent need to develop environmentally friendly, independent, and maintenance-free sensor devices. Since sensor facilities operate in environments with various forms of energy, such as solar, vibration, wind, and acoustic energy, harvesting energy from the environment provides a practical solution for the sustainable power supply of sensor devices. Among these different energy forms, acoustic energy harvesting, as a green, abundant, and sustainable energy source, is gradually becoming a research hotspot.
[0003] Developing novel energy harvesting methods for collecting and utilizing environmental sound energy has broad application value and prospects. However, due to the low energy density of sound energy in the environment, researchers have attempted to design and propose various acoustic energy harvesting technologies with different coupling and enhancement structures. The main types of acoustic enhancement structures include: Helmholtz resonators, half-wave / quarter-wave tube resonators, and acoustic energy harvesting using phononic crystals / metamaterials. By designing these structures to make the incident sound resonate with the acoustic energy harvesting device at a certain frequency, the acoustic energy of a specific frequency and sound pressure level range in the environment can be efficiently harvested and utilized. Furthermore, these acoustic energy harvesting methods utilize piezoelectric materials or electromagnetic structures to convert sound energy into electrical energy, enabling low-power sensors or electrical devices to achieve the purpose of acoustic energy harvesting and utilization.
[0004] However, the resonant frequency of the most widely studied and applied traditional Helmholtz resonator structures depends on the geometry of the resonator chamber and the area of the opening. This limits the specific frequency range they can be tuned, thus potentially making them inflexible for a wide range of sound adjustments. Furthermore, the resonator only works effectively near its resonant frequency, with weaker effects at other frequencies. This can lead to acoustic imbalance because it cannot smoothly handle the entire spectrum, and adjusting the resonator to achieve the desired sound effect may require complex structural parameter adjustments, significantly reducing the flexibility and adjustability of the structure's application. Finally, depending on the arrangement and location of the Helmholtz resonators, they may unintentionally cause sound reflections or echoes. This can produce unwanted acoustic effects. Summary of the Invention
[0005] To address the aforementioned technical problem of the narrow frequency response of existing Helmholtz resonant structures to sound waves, a dual Helmholtz resonant cavity device based on a triboelectric nanogenerator is provided to achieve sound pressure enhancement and a wide frequency response to sound waves.
[0006] The technical means employed in this invention are as follows:
[0007] A dual Helmholtz resonant cavity device based on a triboelectric nanogenerator includes a front Helmholtz resonant cavity and a rear Helmholtz resonant cavity of identical shape. The front and rear Helmholtz resonant cavities are hollow, platform-shaped structures with narrow upper surfaces and wide lower surfaces. The upper surface of the front Helmholtz resonant cavity is connected to the lower surface of the rear Helmholtz resonant cavity and arranged symmetrically. A groove structure is provided on the upper surface of the rear Helmholtz resonant cavity, and a triboelectric nanogenerator is disposed within the groove structure. A porous plate is connected to the lower surface of the front and rear Helmholtz resonant cavities, and a plurality of perforated structures are provided on the porous plate.
[0008] Furthermore, the porous structure includes a connected cylindrical hole and a frustum hole. The lower surface of the cylindrical hole communicates with the upper surface of the frustum hole and has the same size. The area of the lower surface of the frustum hole is larger than the area of the upper surface. The lower surface of the frustum hole is positioned close to the triboelectric nanogenerator.
[0009] Furthermore, the cross-sections of the front Helmholtz resonant chamber and the rear Helmholtz resonant chamber are one of the following: circular, rectangular, or elliptical.
[0010] Furthermore, the triboelectric nanogenerator includes a conductive ink layer, an FEP film, an intermediate ring, and an aluminum film arranged sequentially from the front Helmholtz resonant chamber to the rear Helmholtz resonant chamber.
[0011] Furthermore, the cylindrical hole and the connected frustum hole form a Helmholtz resonant cavity, which absorbs broadband sound waves.
[0012] Furthermore, the formula for the taper of the frustum hole is:
[0013]
[0014] Where c is the speed of sound, r i L is the radius of the cylindrical hole. n V is the thickness of the porous plate, V is the volume of the front or rear Helmholtz resonant chamber, r0 is the radius of the bottom surface of the frustum-shaped hole, and L is the length of the cylindrical hole. p This is the length of the frustum hole.
[0015] Furthermore, the conductive ink layer and the aluminum film are each connected to a wire, which passes through the perforated structure of the porous plate on the rear Helmholtz resonant chamber and is then connected to an external electrical device.
[0016] Compared with the prior art, the present invention has the following advantages:
[0017] This invention employs acoustic energy harvesting technology based on a triboelectric nanogenerator with a dual Helmholtz resonant cavity structure. The symmetrical dual Helmholtz design achieves more stable acoustic energy harvesting, while the multi-pore structure allows for parallel resonance of multiple pores, enhancing sound pressure levels. Furthermore, the tapered neck design allows for adjustment of the neck's taper, thereby changing the resonant frequency of the pores and achieving a wideband acoustic response.
[0018] This invention discloses a taper formula for a frustum hole, which accurately calculates the resonant frequency of the structure. By using the parameters in the formula as a guide, the resonant frequency of the structure can be changed relatively accurately by altering the design parameters of the structure. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention.
[0021] Figure 2 This is a front view of the Helmholtz resonance chamber before and after the present invention.
[0022] Figure 3 This is a three-dimensional view of the Helmholtz resonance chamber before and after the present invention.
[0023] Figure 4 This is a top view of the Helmholtz resonance chamber before and after the present invention.
[0024] Figure 5 This is a three-dimensional view of the overall structure of the present invention.
[0025] Figure 6 This is a three-dimensional view of the porous plate of the present invention.
[0026] Figure 7 This is a front view of the perforated plate of the present invention.
[0027] Figure 8 This is a side sectional view of the Helmholtz resonance chamber of the present invention.
[0028] Figure 9 This is a schematic diagram of the triboelectric nanogenerator structure of the present invention.
[0029] In the figure: 1. Front Helmholtz resonant chamber; 2. Rear Helmholtz resonant chamber; 3. Groove structure; 4. Triboelectric nanogenerator; 5. Porous plate; 6. Cylindrical hole; 7. Frustum hole; 8. Conductive ink layer; 9. FEP film; 10. Intermediate ring; 11. Aluminum film. Detailed Implementation
[0030] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0033] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.
[0034] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.
[0035] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.
[0036] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.
[0037] like Figures 1-9 As shown, this invention provides a dual Helmholtz resonant cavity device based on a triboelectric nanogenerator, comprising a front Helmholtz resonant cavity 1 and a rear Helmholtz resonant cavity 2 of identical shape. The front Helmholtz resonant cavity 1 and the rear Helmholtz resonant cavity 2 are hollow, platform-shaped structures with a narrow upper surface and a wide lower surface. The cross-section of the front Helmholtz resonant cavity 1 and the rear Helmholtz resonant cavity 2 is one of a circle, a rectangle, or an ellipse. The upper surface of the front Helmholtz resonant cavity 1 is connected to the lower surface of the rear Helmholtz resonant cavity 2 and symmetrically arranged. A groove structure 3 is provided on the upper surface of the rear Helmholtz resonant cavity 2, and a triboelectric nanogenerator 4 is disposed within the groove structure 3. A porous plate 5 is connected to the lower surface of the front Helmholtz resonant cavity 1 and the rear Helmholtz resonant cavity 2, and the porous plate 5 has a plurality of perforated structures.
[0038] The perforated structure includes a connected cylindrical hole 6 and a frustum hole 7. The lower surface of the cylindrical hole 6 is connected to the upper surface of the frustum hole 7 and has the same size. The area of the lower surface of the frustum hole 7 is larger than the area of the upper surface. The lower surface of the frustum hole 7 is located close to the triboelectric nanogenerator 4.
[0039] The formula for the taper of a frustum hole is:
[0040]
[0041] Where c is the speed of sound, r i L is the radius of the cylindrical hole. n V is the thickness of the porous plate, V is the volume of the front or rear Helmholtz resonant chamber, r0 is the radius of the bottom surface of the frustum-shaped hole, and L is the length of the cylindrical hole. p This is the length of the frustum hole.
[0042] The triboelectric nanogenerator 4 includes a conductive ink layer 8, an FEP film 9, an intermediate ring 10, and an aluminum film 11 arranged sequentially from the front Helmholtz resonant chamber 1 to the rear Helmholtz resonant chamber 2.
[0043] The conductive ink layer 8 and the aluminum film 11 are each connected to a wire. The wire passes through the perforated structure of the porous plate 5 on the rear Helmholtz resonant chamber 2 and is then connected to an external electrical device.
[0044] The present invention employs a double Helmholtz symmetric structure with multiple conical hole structures, which can place the triboelectric nanogenerator 4 at the center of the symmetric structure, thereby absorbing broadband sound waves through the structure and further enhancing the sound pressure of the sound waves.
[0045] The Helmholtz structure is a unique structure capable of inducing acoustic resonance. It typically consists of a small space at the front end connected to a large space at the rear end; by adjusting the structural parameters, different frequencies of sound waves can resonate. In this structure, a single neck and anterior chamber form a traditional Helmholtz structure, but because it contains multiple necks, it is a porous Helmholtz structure.
[0046] The dual Helmholtz resonant cavity, acting as a sound pressure amplifier, enhances sound pressure through resonance with the sound wave. Furthermore, the symmetrical arrangement of the dual Helmholtz cavities reduces the risk of interference from external sound waves. Compared to a single resonator, the dual Helmholtz resonator offers advantages in overall efficiency and the stability of acquired acoustic data because it can mitigate the interference of reflected sound waves on the triboelectric nanogenerator 4 to some extent. The rear Helmholtz resonant cavity 2 prevents rearward sound waves from acting on the aluminum diaphragm 11, filtering out the sound waves. The front Helmholtz resonant cavity 1 ensures that the device only receives sound waves from the front, filtering out sound waves from the top, bottom, left, and right.
[0047] Triboelectric nanogenerators 4 convert the concentrated and amplified acoustic vibration energy into electrical energy output through triboelectric effect and electrostatic induction. Compared with piezoelectric energy conversion materials, triboelectric nanogenerators have higher output performance.
[0048] A multi-hole resonant structure consists of multiple hole-like structures. Each hole acts as an individual Helmholtz resonator, thus the structure comprises many parallel Helmholtz resonators. This allows for the concentration of sound energy and amplification of sound pressure. When a sound wave propagates through a hole, the wave at that hole is considered a new, independent wave source. The increase in the number of independent wave sources leads to the superposition of sound waves passing through different holes, enhancing the pressure within the cavity.
[0049] The aperture structure allows for alteration of the resonant frequency of the frustum-shaped aperture by changing its taper. Each aperture structure functions as an individual Helmholtz resonator, possessing its own resonant frequency through adjustment of the frustum-shaped aperture. Therefore, the combined effect of multiple resonators can produce a more complex broadband response.
[0050] During operation, the sound wave propagates from the sound source to the double Helmholtz resonant structure. The sound wave passes through multiple perforated structures and undergoes broadband resonance, thereby enhancing the sound pressure and achieving a broadband response.
[0051] The triboelectric nanogenerator 4 adopts a sandwich structure, consisting of four parts: an aluminum film 11, an intermediate ring 10, an FEP film 9, and a conductive ink layer 8. The FEP film 8 and the aluminum film 11 are both common materials in triboelectric nanogenerator energy harvesting devices.
[0052] Optionally, the number of pores in the porous structure is adjustable, the taper of the porous neck is adjustable, the arrangement and combination of pores with different neck taper ratios is adjustable, the porous radius and pore depth of the dual Helmholtz resonator are adjustable, and the size of the sandwich structure layer of the triboelectric nanogenerator is adjustable.
[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A dual Helmholtz resonant cavity device based on a triboelectric nanogenerator, characterized in that, It includes a front Helmholtz resonant chamber (1) and a rear Helmholtz resonant chamber (2) with the same shape. The front Helmholtz resonant chamber (1) and the rear Helmholtz resonant chamber (2) are hollow platform-shaped structures with narrow upper surfaces and wide lower surfaces. The upper surfaces of the front Helmholtz resonant chamber (1) and the rear Helmholtz resonant chamber (2) are connected and symmetrically arranged. A groove structure (3) is provided on the upper surface of the rear Helmholtz resonant chamber (2). A triboelectric nanogenerator (4) is provided in the groove structure (3). A porous plate (5) is connected to the lower surfaces of the front Helmholtz resonant chamber (1) and the rear Helmholtz resonant chamber (2). A number of pore-shaped structures are provided on the porous plate (5) that penetrate the porous plate (5). The perforated structure includes a connected cylindrical hole (6) and a frustum hole (7). The lower surface of the cylindrical hole (6) is connected to the upper surface of the frustum hole (7) and has the same size. The area of the lower surface of the frustum hole (7) is larger than the area of the upper surface. The lower surface of the frustum hole (7) is located close to the triboelectric nanogenerator (4). The cylindrical hole (6) and the connected frustum hole (7) form a Helmholtz resonant cavity, which absorbs broadband sound waves. The taper formula for the frustum hole (7) is: in, c For the speed of sound, r i Where is the radius of the cylindrical hole. L n For the thickness of the perforated plate, V This refers to the chamber volume of the pre-Helmholtz resonance chamber or the post-Helmholtz resonance chamber. r 0 is the radius of the bottom surface of the frustum hole. L The length of the cylindrical hole. L p This is the length of the hole in the frustum.
2. The dual Helmholtz resonant cavity device based on a triboelectric nanogenerator according to claim 1, characterized in that, The cross-sections of the front Helmholtz resonant chamber (1) and the rear Helmholtz resonant chamber (2) are one of the following: circular, rectangular, or elliptical.
3. The dual Helmholtz resonant cavity device based on a triboelectric nanogenerator according to claim 1, characterized in that, The triboelectric nanogenerator (4) includes a conductive ink layer (8), an FEP film (9), an intermediate ring (10), and an aluminum film (11) arranged sequentially from the front Helmholtz resonant chamber (1) to the rear Helmholtz resonant chamber (2).
4. The dual Helmholtz resonant cavity device based on a triboelectric nanogenerator according to claim 3, characterized in that, The conductive ink layer (8) and the aluminum film (11) are respectively connected to a wire, which passes through the perforated structure of the porous plate (5) on the rear Helmholtz resonant chamber (2) and is then connected to an external electrical device.