A method for acoustic energy conversion into electrical energy

Abstract

A method for converting sound energy into electrical energy includes a sound wave entering a resonant cavity of an acoustic metamaterial through an inlet. The resonant cavity responds to the sound wave, and a sound pressure distribution region comprising at least one sound pressure level is formed within the resonant cavity. A wobbly elastic mechanism disposed within the sound pressure distribution region is moved by the sound pressure, and a nano-power generation unit disposed on the wobbly elastic mechanism is driven by the wobbly elastic mechanism to generate electrical energy. The wobbly elastic mechanism includes a first elastic element and a second elastic element that moves relative to and is spaced apart from the first elastic element. The nano-power generation unit includes a first nanogenerator, and the first nanogenerator has a first friction plate and a second friction plate respectively mounted on the first elastic element and the second elastic element.

Description

Technical Field

[0001] This invention relates to a method for converting acoustic energy into electrical energy, and more particularly to a method for converting acoustic energy into electrical energy using acoustic metamaterials. Prior Technology

[0002] With increasing environmental awareness, energy development is gradually shifting towards green energy. Sound energy is a clean and widely distributed form of energy in the environment, therefore, converting sound energy into electrical energy has gradually become a research hotspot for researchers in the field of green energy.

[0003] Chinese Patent Publication No. CN117037757A discloses an acoustic metamaterial for low-frequency sound insulation and sound energy capture. This acoustic metamaterial comprises an acoustic metamaterial and a nanogenerator disposed on the acoustic metamaterial. The acoustic metamaterial includes a central frustum, a thin film disposed on the outer wall of the central frustum, and a cylindrical mass block disposed on the outer wall of the thin film.

[0004] Although the acoustic metamaterial can convert acoustic energy into electrical energy, the thin film of the acoustic metamaterial has the problem of not being able to precisely control the tension. Therefore, it is necessary to provide a novel way to convert acoustic energy into electrical energy without using thin film acoustic metamaterials. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide a method for converting sound energy into electrical energy.

[0006] A method for converting sound energy into electrical energy includes a sound wave entering a resonant cavity of an acoustic metamaterial through an inlet, and the resonant cavity responding to the sound wave, wherein a sound pressure distribution region including at least one sound pressure is formed in the resonant cavity.

[0007] A swingable elastic mechanism disposed within the sound pressure distribution area is moved by the sound pressure. The swingable elastic mechanism includes a first elastic element and a second elastic element that moves relative to the first elastic element and is spaced apart from the first elastic element.

[0008] A nano-power generation unit disposed on the swingable elastic mechanism is driven by the swingable elastic mechanism to generate electrical energy. The nano-power generation unit includes a first nano-generator, and the first nano-generator has a first friction plate and a second friction plate respectively mounted on the first elastic member and the second elastic member.

[0009] The advantages of this invention are: the resonant cavity responds to the sound wave to form the sound pressure distribution area, and the oscillating elastic mechanism is driven to move by the sound pressure; simultaneously, the nano-power generation unit is driven by the oscillating elastic mechanism to generate electrical energy, thereby achieving the purpose of converting sound energy into electrical energy. Simple Explanation of the Diagram

[0010] Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: Figure 1 is a three-dimensional schematic diagram of an acoustic metamaterial and a swingable elastic mechanism according to a first embodiment of the method for converting acoustic energy into electrical energy of the present invention; Figure 2 is a top view of the acoustic metamaterial of the first embodiment; Figure 3 is a schematic diagram of the swingable elastic mechanism and a nano-power generation unit of the first embodiment; Figure 4 is a schematic diagram of a swingable elastic mechanism and a nano-power generation unit according to a second embodiment of the method for converting sound energy into electrical energy of the present invention; Figure 5 is a schematic diagram of a swingable elastic mechanism and a nano-power generation unit according to a third embodiment of the method for converting sound energy into electrical energy of the present invention; Figure 6 is a schematic diagram illustrating the swinging behavior and displacement of the swingable elastic mechanism in the third embodiment when the sound wave frequency is 1000 Hz. Figure 7 is a schematic diagram illustrating the oscillation and displacement of the oscillating elastic mechanism in the third embodiment when the sound wave frequency is 3000 Hz; and Figure 8 is a schematic diagram illustrating the swinging behavior and displacement of the swingable elastic mechanism in the third embodiment when the sound wave is 4000Hz. Implementation

[0011] Before the invention is described in detail, it should be noted that similar elements are represented by the same numbers in the following description.

[0012] A first embodiment of the method for converting acoustic energy into electrical energy according to the present invention is performed by an acoustic energy-to-electrical-energy device. Referring to Figures 1 and 2, the acoustic energy-to-electrical-energy device includes an acoustic metamaterial 2, a swingable elastic mechanism 3, and a nano-power generation unit 4.

[0013] Referring to Figures 1 and 3, the acoustic metamaterial 2 includes a bottom wall 21, a surrounding wall 22, a top wall 23, a first wall 24, and two second walls 25. The surrounding wall 22 extends from the periphery of the bottom wall 21 away from the periphery and forms an entrance 26 for sound waves to enter. The top wall 23 is spaced apart from the bottom wall 21 and connected to the top of the surrounding wall 22.

[0014] The first wall 24 extends from the bottom wall 21 toward the top wall 23 and is spaced apart from the entrance 26.

[0015] The second walls 25 extend from opposite sides of the first wall 24 in a direction opposite to the inlet 26, and from the bottom wall 21 toward the top wall 23. The second walls 25 and the first wall 24 together define a resonant cavity 241, which has an opening 252 communicating with the inlet 26. A slot 251 is formed on one surface of one of the second walls 25. The acoustic metamaterial 2 has different absorption coefficients for sound waves of different frequencies. In some embodiments, the absorption coefficient of the acoustic metamaterial 2 is between 0.8 and 1.

[0016] It is worth noting that the structure of this acoustic metamaterial is not limited to the structures described above, and it can also employ conventional resonant sound absorbers, such as Helmholtz resonators, dual-cavity resonators, slit resonators, or labyrinth resonators. The structural design of this acoustic metamaterial can be adjusted according to the required resonant frequency of the acoustic metamaterial or the specific frequency of sound waves to be matched.

[0017] Referring to Figures 1 and 2, the swingable elastic mechanism 3 includes an insert 31, a first elastic element 32, and a second elastic element 33 that moves relative to the first elastic element 32. In this first embodiment, the insert 31, the first elastic element 32, and the second elastic element 33 are manufactured using 3D printing.

[0018] The insert 31 is elongated and is installed in the slot 251.

[0019] The first elastic member 32 is U-shaped, and the two oppositely arranged ends 321 of the first elastic member 32 are connected to the insert 31, so that the first elastic member 32 and the insert 31 together define a first moving space 320.

[0020] The second elastic member 33 is disposed within the first moving space 320. The second elastic member 33 is U-shaped, and its two oppositely disposed ends 331 are connected to the insert 31, so that the second elastic member 33 and the insert 31 together define a second moving space 330.

[0021] The thicknesses of the first elastic element 32 and the second elastic element 33 can be adjusted according to the sound pressure level generated by the acoustic metamaterial 2 in response to the sound wave, the required electrical energy, or the required displacement of the oscillating elastic mechanism 3. In some embodiments, the thickness of either the first elastic element 32 or the second elastic element 33 is not greater than 1 mm. The materials of the first elastic element 32 and the second elastic element 33 are not particularly limited, for example, but not limited to, 3D printing resin. The Young's modulus of the first elastic element 32 and the second elastic element 33 can be adjusted according to the sound pressure level generated by the acoustic metamaterial 2 in response to the sound wave, the required electrical energy, or the required displacement of the oscillating elastic mechanism 3. In some embodiments, the Young's modulus of either the first elastic element 32 or the second elastic element 33 is less than 10 MPa. In some embodiments, the Young's modulus of either the first elastic element 32 or the second elastic element 33 is 9 MPa or less.

[0022] The nano-power generation unit 4 includes three spaced-apart first nano-generators 41. Each first nano-generator 41 has a first friction plate 411, a second friction plate 412 opposite to the first friction plate 411, and a wire (not shown) connecting the first friction plate 411 and the second friction plate 412. The first friction plates 411 are disposed on the first elastic member 32 and located between the first elastic member 32 and the second elastic member 33, wherein two are respectively disposed on two bends of the first elastic member 32, and the other is disposed between the bends of the first elastic member 32. The second friction plates 412 are disposed on the second elastic member 33 and located between the first elastic member 32 and the second elastic member 33, wherein two are respectively disposed on two bends of the second elastic member 33, and the other is disposed between the bends of the second elastic member 33. In some embodiments, the first friction plates 411 and the second friction plates 412 are in contact with each other. In some embodiments, the first friction plate 411 and the second friction plate 412 are spaced apart. It is worth noting that the number of such first nanogenerators 41 is not limited to three; it can be one, two, or four, etc.

[0023] In the method for converting sound energy into electrical energy according to the first embodiment of the present invention, a sound wave enters the resonant cavity 241 through the inlet 26 of the acoustic metamaterial 2. Then, the resonant cavity 241 responds to the sound wave, and a sound pressure distribution region including at least one sound pressure is formed within the resonant cavity 241. The oscillating elastic mechanism 3 is disposed within the sound pressure distribution region and is moved by the sound pressure. The nano-power generation unit 4 disposed on the oscillating elastic mechanism 3 is driven by the oscillating elastic mechanism 3 to generate electrical energy.

[0024] The sound wave is, for example, a sound wave with a frequency of 20 Hz to 4000 Hz.

[0025] When the frequency of the sound wave matches the resonant frequency of the resonant cavity 241, the sound wave can be amplified in the resonant cavity 241, thereby forming the sound pressure distribution area in the resonant cavity 241, and different degrees of sound pressure will be formed in different directions in the sound pressure distribution area.

[0026] The sound pressure can drive the oscillating elastic mechanism 3 to oscillate and deform, thereby converting the sound pressure into mechanical energy. Since there are different degrees of sound pressure in different directions within the sound pressure distribution area, the direction of displacement or oscillation of the oscillating elastic mechanism 3 can be up, down, forward, backward, left, or right, or an irregular direction, such as diagonally forward or diagonally backward. It is worth noting that the sound pressure distribution can be in a single direction and can be adjusted according to the structural design of the acoustic metamaterial 2 or the resonant cavity 241.

[0027] In this first embodiment, the larger sound pressure is concentrated between the two bends of the second elastic member 33, causing the sound pressure to drive the second elastic member 33 to produce a relative displacement with the first elastic member 32, thereby electrifying the second friction plate 412 and the first friction plate 411 through friction or electrostatic induction, so as to convert the sound wave into electrical energy.

[0028] Referring to Figure 4, a second embodiment of the method for converting sound energy into electrical energy according to the present invention is similar to the first embodiment, except that the swingable elastic mechanism 3 and the nano-power generation unit 4 are different.

[0029] In this second embodiment, the swingable elastic mechanism 3 of the sound-to-electricity conversion device further includes a third elastic member 34 disposed within the second moving space 330 and movable relative to the second elastic member 33. The third elastic member 34 is rectangular and defines a third moving space 340, and has two opposite ends 341 connected to the second elastic member 33. In this second embodiment, the third elastic member 34, the insert 31, the first elastic member 32, and the second elastic member 33 are manufactured using 3D printing.

[0030] The nano-power generation unit 4 also includes four spaced-apart second nano-generators 42 and a third nano-generator 43 spaced-apart from the second nano-generators 42.

[0031] Each of the second nanogenerators 42 has a third friction plate 421 and a fourth friction plate 422. Each third friction plate 421 is disposed on the insert 31 and located between the insert 31 and the third elastic member 34. Each fourth friction plate 422 is disposed on the third elastic member 34 and located between the insert 31 and the third elastic member 34, and is disposed opposite to the third friction plate 421.

[0032] The third nanogenerator 43 has a fifth friction plate 431 and a sixth friction plate 432. The fifth friction plate 431 is disposed on the second elastic member 33 and located between the second elastic member 33 and the third elastic member 34. The sixth friction plate 432 is disposed on the third elastic member 34 and located between the second elastic member 33 and the third elastic member 34, and is disposed opposite to the fifth friction plate 431.

[0033] It is worth noting that the number of the second nanogenerator 42 is not limited to four; it can be one, two, or five, etc. Similarly, the number of the third nanogenerator 43 is not limited to one; it can be two, three, or four, etc.

[0034] In the method for converting sound energy into electrical energy in the second embodiment of the present invention, the third elastic member 34 can also be driven by the sound pressure to move or deform.

[0035] Referring to Figure 5, a third embodiment of the method for converting sound energy into electrical energy according to the present invention is similar to the second embodiment, except that the swingable elastic mechanism 3 and the nano-power generation unit 4 are different.

[0036] In this third embodiment, the swingable elastic mechanism 3 further includes a fourth elastic element 35 and an adjusting element 36. The fourth elastic element 35 is disposed within the third moving space 340. The fourth elastic element 35 is U-shaped, and its two oppositely disposed ends 351 are connected to the third elastic element 34 and are movable relative to the third elastic element 34. The adjusting element 36 is cylindrical and connected between the two bends of the fourth elastic element 35. The weight of the adjusting element 36 can be adjusted, thereby causing a corresponding change in the weight of the swingable elastic mechanism 3, and thus adjusting the displacement of the swingable elastic mechanism 3. In this third embodiment, the adjusting element 36, the fourth elastic element 35, the insert 31, the first elastic element 32, the second elastic element 33, and the third elastic element 34 are manufactured using 3D printing.

[0037] The nano-power generation unit 4 also includes a fourth nano-generator 44. The fourth nano-generator 44 has a seventh friction plate 441 and an eighth friction plate 442. The seventh friction plate 441 is disposed on the third elastic member 34 and located between the third elastic member 34 and the fourth elastic member 35. The eighth friction plate 442 is disposed on the fourth elastic member 35 and located between the third elastic member 34 and the fourth elastic member 35, and is disposed opposite to the seventh friction plate 441.

[0038] In the method for converting sound energy into electrical energy in the third embodiment of the present invention, the fourth elastic member 35 can also be driven by the sound pressure to move or deform.

[0039] In this third embodiment, the acoustic metamaterial 2 of this third embodiment has sound absorption coefficients of 0.15, 0.42, and 0.72 for sound waves of 1000Hz, 3000Hz, and 4000Hz, respectively. Referring to Figures 6 to 8, these figures are schematic diagrams showing the swinging and displacement of the swingable elastic mechanism 3 of the third embodiment when the sound waves are 1000Hz, 3000Hz, and 4000Hz. As can be seen from Figures 6 to 8, the sound pressure acts on the first elastic element 32, the second elastic element 33, the third elastic element 34, the fourth elastic element 35, and the adjusting element 36, causing the first elastic element 32, the second elastic element 33, the third elastic element 34, and the fourth elastic element 35 to undergo displacement or deformation, so that the swingable elastic mechanism 3 can move or swing in multiple different directions. Furthermore, with the design of the resonant cavity 241, the resonant cavity 241 responds to the sound wave, causing the formed sound pressure distribution area to be mainly located in the position region of the second elastic element 33, the third elastic element 34, and the fourth elastic element 35. Therefore, compared to the displacement of the first elastic element 32, the second elastic element 33, the third elastic element 34, and the fourth elastic element 35 have larger displacements, with the second elastic element 33 having the largest displacement. Based on this, setting the nano-power generation unit 4 on the second elastic element 33 and the first elastic element 32 helps to generate a larger amount of electrical energy.

[0040] In summary, in the method of converting sound energy into electrical energy of the present invention, the acoustic metamaterial 2 absorbs the sound wave, and generates sound pressure in the resonant cavity 241 of the acoustic metamaterial 2. The sound pressure drives the swingable elastic mechanism 3 disposed in the resonant cavity 241 to produce displacement or deformation, thereby converting the sound pressure into mechanical energy. Then, the mechanical energy drives the nano-power generation unit 4 to generate electricity, thereby converting the mechanical energy into electrical energy. Therefore, the purpose of the present invention can indeed be achieved.

[0041] However, the above description is merely an embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the scope of the patent application and the contents of the patent specification of the present invention shall still fall within the scope of the patent of the present invention.

[0042] 2: Acoustic Metamaterials 21:Bottom wall 22: Surrounding the wall 23: Top Wall 24: First Wall 241: Resonance Cavity 25: The Second Wall 251: Slot 252: Opening 26: Entrance 3: Oscillating elastic mechanism 31: Inserts 32: First elastic element 320: First Mobile Space 321:End 33: Second elastic element 330: Second Mobile Space 331:End 34: Third elastic element 340: The Third Mobile Space 341:End 35: Fourth elastic element 351:End 36: Adjustment element 4: Nano-power generation unit 41: The First Nanogenerator 411: First friction plate 412: Second friction plate 42: Second Nanogenerator 421: Third friction plate 422: Fourth friction plate 43: Third Nanogenerator 431: Fifth friction plate 432: Sixth friction plate 44: Fourth Nanogenerator 441: Seventh friction plate 442: Eighth friction plate

Claims

1. A method for converting sound energy into electrical energy, comprising: a sound wave entering a resonant cavity of an acoustic metamaterial via an inlet, the resonant cavity responding to the sound wave, and forming a sound pressure distribution region including at least one sound pressure level within the resonant cavity, wherein... The acoustic metamaterial has a bottom wall, a surrounding wall extending from the periphery of the bottom wall away from the periphery and forming the entrance, a top wall spaced apart from the bottom wall and connected to the top of the surrounding wall, a first wall extending from the bottom wall toward the top wall and spaced apart from the entrance, and two second walls extending from opposite sides of the first wall toward directions opposite to the entrance. The first wall and the second walls together define a resonant cavity having an opening communicating with the entrance. A swingable elastic mechanism disposed within the sound pressure distribution area is driven to move by the sound pressure. The swingable elastic mechanism includes a first elastic element and a second elastic element that moves relative to the first elastic element and is spaced apart from the first elastic element. A nano-power generation unit disposed on the swingable elastic mechanism is driven by the swingable elastic mechanism to generate electrical energy. The nano-power generation unit includes a first nano-generator, and the first nano-generator has a first friction plate and a second friction plate respectively mounted on the first elastic element and the second elastic element.

2. The method for converting sound energy into electrical energy as described in claim 1, wherein, One surface of one of the second walls is formed with a slot, and the oscillating elastic mechanism further includes an insert mounted on the slot, the insert being connected to the first elastic member and the second elastic member.

3. The method for converting sound energy into electrical energy as described in claim 2, wherein, The first elastic member is U-shaped and its two opposite ends are connected to the insert, so that the first elastic member and the insert together define a first moving space, and the second elastic member is disposed in the first moving space.

4. The method for converting sound energy into electrical energy as described in claim 3, wherein, The second elastic member is U-shaped and its two opposite ends are connected to the insert, so that the second elastic member and the insert define a second moving space. The swingable elastic mechanism also includes a third elastic member, which is disposed in the second moving space, connected to the second elastic member, and moves relative to the second elastic member.

5. The method for converting sound energy into electrical energy as described in claim 4, wherein, The third elastic member has two opposite ends and these ends are connected to the second elastic member so that the third elastic member and the second elastic member together define a third moving space. The swingable elastic mechanism also includes a U-shaped fourth elastic member, which is disposed in the third moving space and whose two opposite ends are connected to the third elastic member and move relative to the third elastic member.

6. The method for converting sound energy into electrical energy as described in claim 5, wherein, The nano-power generation unit also includes a second nano-generator, which has a third friction plate and a fourth friction plate respectively mounted on the insert and the third elastic member.

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