Acoustic metamaterial structures and geometries for sound amplification and / or cancellation

Abstract

The present invention discloses geometric configurations and embodiments of acoustic metamaterial structures that produce sound amplification or cancellation. An acoustic metamaterial device for use with a sound source includes a plurality of fins, wherein each fin is made of a material that is very dense relative to air, the material producing anisotropic properties of the acoustic metamaterial device, wherein each fin has a length dimension, a width dimension, and a thickness dimension, the width and length dimensions being equal and substantially perpendicular to the direction of propagation of sound waves from the sound source, wherein each fin has a different dimension from the other fins along the width and length dimensions, and wherein the plurality of fins are interconnected such that a plane formed by the width and length dimensions of each fin is perpendicular to the direction of propagation of sound waves from the sound source.

Description

Technical Field

[0001] The present invention relates to acoustic metamaterial structures and geometric configurations of acoustic metamaterial structures that produce sound amplification and / or cancellation. Background Art

[0002] Acoustic metamaterials are synthetic materials designed to manipulate sound wave propagation, resulting in acoustic transformation behaviors not typically observed in natural materials. For example, a technology demonstrator called an acoustic superlens, built using acoustic metamaterials, can transform near-field waves into far-field waves. The acoustic superlens propagates sound waves along the air gaps between radial fins made of very dense materials such as brass. Summary of the Invention

[0003] The present invention discloses embodiments of acoustic metamaterial structures and geometric configurations of acoustic metamaterial structures that produce sound amplification or cancellation. In one embodiment, an acoustic metamaterial device for use with a sound source includes a plurality of fins, wherein each fin is made of a material that is very dense relative to air, which produces anisotropic properties of the acoustic metamaterial device, wherein each fin has a length dimension, a width dimension, and a thickness dimension, wherein the width and length dimensions are equal and substantially perpendicular to the direction of propagation of sound waves from the sound source, wherein each fin has a different dimension from the other fins along the width and length dimensions, and wherein the plurality of fins are interconnected such that a plane formed by the width and length dimensions of each fin is perpendicular to the direction of propagation of sound waves from the sound source.

[0004] In one embodiment, a noise cancellation device includes a plurality of fin sections, each fin section including a plurality of fins, wherein each fin is made of a material that is very dense relative to air, which produces anisotropic properties of the acoustic metamaterial device, wherein each fin has a first dimension, a second dimension, and a third dimension, wherein two of the first dimension, the second dimension, and the third dimension are equal and substantially perpendicular to a direction of propagation of sound waves from a sound source, wherein each fin is of different sizes along the two equal-sized directions, wherein the plurality of fins are interconnected such that a plane formed by the two equal dimensions of each fin is perpendicular to the direction of propagation of sound waves from the sound source, and wherein the plurality of fin sections substantially surround the sound source. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication in color will be provided by the Office upon request and payment of the necessary fee.

[0006] The present invention may be better understood from the following detailed description when read in conjunction with the accompanying drawings, which are incorporated into and constitute a part of this specification. It is emphasized that, in accordance with common practice, the various features of the drawings are not drawn to scale. Instead, the dimensions of the various features are arbitrarily expanded or reduced for clarity.

[0007] Figure 1 Schematic diagram of the acoustic superlens and dual-speaker sound source.

[0008] Figure 2 yes Figure 1 A simulated sound field or model of an acoustic metalens.

[0009] Figure 3 is an example acoustic metamaterial fin structure having a fin geometry perpendicular to the sound source, according to certain embodiments.

[0010] Figure 4 is an example acoustic metamaterial fin structure having a fin geometry perpendicular to the sound source, according to certain embodiments.

[0011] Figure 5 is a simulated acoustic field or model of an example acoustic metamaterial fin structure with a fin geometry perpendicular to the sound source, according to certain embodiments.

[0012] Figure 6 It is a simulated sound field or model of an independent speaker.

[0013] Figure 7 is a simulated acoustic field or model of an example acoustic metamaterial fin structure with a fin geometry perpendicular to the sound source, according to certain embodiments.

[0014] Figure 8 According to certain embodiments, Figure 7 Simulated sound pressure plots for the acoustic metamaterial fin structure and a standalone loudspeaker with the fin geometry shown perpendicular to the sound source.

[0015] Figure 9 According to certain embodiments, Figure 7 Measured sound pressure plots of an acoustic metamaterial fin structure and a standalone loudspeaker with the fin geometry shown perpendicular to the sound source.

[0016] Figure 10 is a 2D diagram of an example acoustic metamaterial structure for sound cancellation, according to certain embodiments.

[0017] Figure 11 It is a simulated 2D sound field or model referenced to a single pole source.

[0018] Figure 12is an example acoustic metamaterial fin structure for sound cancellation according to certain embodiments (e.g. Figure 10 A simulated 2D sound field or model (as shown).

[0019] Figure 13 is a perspective view of one metamaterial fin component of an example 3D acoustic metamaterial fin structure for sound cancellation, according to certain embodiments.

[0020] Figure 14 is a perspective view of four metamaterial fin components of an example 3D acoustic metamaterial fin structure for sound cancellation, according to certain embodiments.

[0021] Figure 15 is a perspective view of six metamaterial fin components of an example 3D acoustic metamaterial fin structure for sound cancellation, according to certain embodiments.

[0022] Figure 16 is a simulated acoustic field or model shown in a cross-sectional view of a 3D reference monopole source.

[0023] Figure 17 is a simulated sound field or model shown in a cross-sectional view of a 3D acoustic metamaterial structure for sound cancellation, according to certain embodiments.

[0024] Figure 18 is an example of a flow chart of a method for providing an acoustic metamaterial fin component according to certain embodiments.

[0025] Figure 19 is an example of a flow chart of a method for providing an acoustic metamaterial fin structure composed of a defined number of metamaterial fin components, according to certain embodiments. DETAILED DESCRIPTION

[0026] The accompanying drawings and description provided by the present invention can be simplified to illustrate the aspects of the described embodiments, which are relevant to clearly understanding the process, machine, manufactured goods and / or material composition disclosed by the present invention, while excluding other aspects that may be found in typical similar equipment, systems, compositions and methods for the sake of clarity. Therefore, those skilled in the art will recognize that other elements and / or steps may be desirable or necessary for realizing equipment, systems, compositions and methods described in the present invention. However, because these elements and steps are well known in the art, and because they do not contribute to a better understanding of the disclosed embodiments, discussion of these elements and steps may not be provided herein. However, the present invention is considered to inherently include all such elements, variations and modifications to the described aspects that those of ordinary skill in the relevant art will know according to the discussion herein.

[0027] Embodiments are provided in the present invention so that the present invention is fully and thoroughly and the scope of the disclosed embodiments is fully conveyed to those skilled in the art. Many specific details, such as examples of specific aspects, devices and methods, are set forth to provide a thorough understanding of embodiments of the present invention. However, it will be apparent to those skilled in the art that it is not necessary to adopt certain specific disclosed details, and that the embodiments may be embodied in different forms. Therefore, the exemplary embodiments set forth should not be construed as limiting the scope of the present invention.

[0028] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. For example, 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. The terms "comprise," "include," "contain," and "have" are inclusive and, therefore, specify the presence of the recited features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof.

[0029] Therefore, the steps, processes, and operations described herein should not be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless expressly identified as a preferred or desired order of performance. It should also be understood that additional or alternative steps may be employed in place of or in combination with the disclosed aspects.

[0030] In addition, although the term first, second, third etc. can be used to describe various elements, steps or aspects in the present invention, these elements, steps or aspects should not be limited by these terms.These terms are only used to distinguish an element or aspect from another element or aspect.Therefore, unless the context clearly points out, otherwise the terms such as "first", "second" and other numerical terms do not imply sequence or order when used in the present invention.Therefore, without departing from the teaching of the present invention, the first element, step, parts, region, layer or part discussed below can be referred to as the second element, step, parts, region, layer or part.

[0031] The non-limiting embodiments described herein are directed to structures and devices, and methods for making the same, wherein the structures and devices are acoustic metamaterial structures and geometric configurations of acoustic metamaterial structures that produce sound amplification and / or cancellation. Within the spirit and scope of the claims, the structures and devices, and methods for making the structures and devices, may be modified for various applications and uses. The embodiments and variations described herein and / or shown in the accompanying drawings are presented as examples only and are not limiting of the scope and spirit. The description of the present invention is applicable to all embodiments of the devices and methods for making the devices.

[0032] Embodiments of acoustic metamaterial structures and geometric configurations of acoustic metamaterial structures that produce sound amplification and / or cancellation, as well as methods for fabricating acoustic metamaterial structures, are disclosed.

[0033] Acoustic metamaterials are artificially synthesized materials designed to manipulate sound wave propagation, resulting in acoustic transformation behaviors not typically observed in natural materials. This manipulation of sound wave propagation leads to unique acoustic transformations and potential real-world applications. When a propagating sound wave of a certain frequency encounters a structural object in its path, its propagation behavior is altered due to the object's geometry and material properties. These changes in wave propagation are the result of diffraction around the object, refraction through the object, and reflection away from the object. In acoustic metamaterials, these structural objects are periodic unit cells embedded within the material itself, and the overall material properties are therefore characterized using an effective parameter approach. This approach avoids the complexity of acoustic wave interactions at each individual periodic unit cell. Thus, acoustic metamaterials leverage their inherent periodic unit cell structure to manipulate effective material properties such as mass density and bulk modulus. These effective properties, in turn, influence the material's anisotropy and refractive index, leading to unique and predictable sound wave propagation. Typically, objects made of acoustic metamaterials use periodic structural units to manipulate the object's effective mass density and bulk modulus to determine material properties such as anisotropy and refractive index, creating unique acoustic transformation functions.

[0034] Figure 1 is a schematic diagram of the acoustic metalens 100, Figure 2 yes Figure 1 Figure 200 shows the acoustic field or pattern 200 of the acoustic superlens 100. The acoustic superlens 100 is a metamaterial that can convert near-field waves into far-field waves. The inherent anisotropic properties of this metamaterial facilitate the conversion. As shown, the acoustic superlens 100 includes a plurality of fins 110 that originate from or radiate relative to a dual-speaker sound source 120. The fins 110 can be made of a very dense material, such as but not limited to brass, which produces the anisotropic properties of the acoustic superlens. The acoustic superlens 100 has a geometric configuration in which sound waves propagate along the air gaps between the fins 100. Figure 2 yes Figure 1 The simulated sound field or model of the acoustic metalens. Figure 2 As shown, by having controlled directivity and continuous separation of multiple sound sources, the acoustic metalens 100 allows two different sound fields located in the near field 210 to propagate into the far field 220 as separate sound sources.

[0035] Figure 3is a 2D diagram of an example acoustic metamaterial fin structure 300 having a fin geometry perpendicular to a sound source 320 according to certain embodiments. The acoustic metamaterial fin structure 300 includes a plurality of fins 310 that are perpendicular to a single sound source 320. In one embodiment, the fins 310 are made of a material that is very dense relative to the density of air, including but not limited to brass, which promotes the anisotropic properties of the structure by manipulating the bulk modulus and / or mass density in different directions throughout the structure. Each fin 310 is wider (or longer) in a direction perpendicular to the sound source 320, and each fin 310 is symmetrical about a line 330 drawn from the sound source 320. The fin spacing, fin width, fin thickness, and number of fins 310 can depend on the frequency of interest, the wavelength of interest, etc. In one embodiment, an air layer is between each fin 310.

[0036] Figure 4 is an example acoustic metamaterial fin structure 400 having a fin geometry perpendicular to a sound source 420 according to certain embodiments. The acoustic metamaterial fin structure 400 includes a plurality of fins 410 perpendicular to the sound source 420. In one embodiment, the fins 410 are made of a very dense material, including but not limited to, for example, brass, which promotes anisotropic properties of the structure by manipulating the bulk modulus and / or mass density in different directions throughout the structure. The fin spacing, fin width, fin thickness, and the number of fins 410 can depend on the frequency of interest, the wavelength of interest, the application, the environment, etc. Therefore, the fin relationship can vary. In one embodiment, the fin relationship can cover angles up to 65°. Each fin 410 has the same or substantially the same fin thickness. In one embodiment, the fin thickness can be between 5-15 mm. The spatial spacing between each fin 410 is the same or substantially the same. In one embodiment, the spatial spacing can be between 5-15 mm. The wider the fin width of each fin 410 (in a vertical direction relative to a single sound source 420), the farther the fin 410 is from the sound source 420, and each fin 410 is symmetrical about a line 430 drawn from the sound source 420. In one embodiment, the fin width can be 19.05-24.5 mm, and each subsequent fin width can be defined according to the fin relationship.

[0037] Figure 5 Figure 2 is a simulated acoustic field or model of an example acoustic metamaterial fin structure with a fin geometry perpendicular to the sound source, according to certain embodiments. Amplitude enhancement of the original sound source is observed through redirection of sound wave propagation. In one embodiment, the acoustic signal-to-noise ratio can be improved by redirecting the sound waves back to the transducer through the metamaterial. Figure 66 is a simulated sound field or model 600 of an independent speaker 610. The simulated sound field or model 500 can be compared with the sound field or model 600 of the independent speaker 610. As shown, the sound pressure level of the reflected waves in the simulated sound field or model 500 is enhanced.

[0038] Figure 7 The acoustic field or model of an example acoustic metamaterial fin structure with fin geometry perpendicular to the sound source, according to certain embodiments, is shown 700. Amplitude enhancement of the original sound source is observed through redirection of sound wave propagation. Figure 8 800 is a simulated sound pressure graph of an acoustic metamaterial fin structure with a fin geometry perpendicular to the sound source and a standalone loudspeaker according to certain embodiments. Figure 7 The cut arc 710 shown in FIG, shows an enhancement in the sound pressure level 810 of the acoustic metamaterial fin structure with the fin geometry perpendicular to the sound source relative to the sound pressure level 820 of an isolated sound source. The simulated enhanced sound pressure level is approximately 25 dB higher compared to an isolated sound source along the cut arc 710. Figure 9 FIG. 9 is a graph of measured sound pressure for an acoustic metamaterial fin structure having a fin geometry perpendicular to the sound source and a standalone loudspeaker according to certain embodiments. The measured enhanced sound pressure level 910 is generally higher than that along Figure 7 Figure 9 shows the sound pressure level 920 of an independent sound source for the cutting arc 710. As shown, the vertical fin orientation enhances and redirects the sound waves.

[0039] In one embodiment, Figure 3-9 The acoustic metamaterial fin structure and vertical geometric fin configuration shown and described in the present invention can be used in a self-contained noise cancelling metamaterial structure. The self-contained noise cancelling metamaterial structure can reduce unwanted noise emitted from various devices such as pumps, fans, motors, actuators, etc. The above-mentioned devices can be found in equipment used in the medical, commercial and manufacturing industries. The self-contained noise cancelling metamaterial structure can reduce unwanted noise emissions from any internal source within the metamaterial structure by using less space, less material and additive manufacturing technology. In addition, the self-contained noise cancelling metamaterial structure can be used with any product that is considered to have reached a noise level that is harmful to the end user. This includes OHSA safe exposure levels and annoyance levels. Noise reduction can also be used in manufacturing environments to improve processes and working conditions. Compared with traditional methods, the above-mentioned metamaterial structure requires significantly less material to provide the same noise reduction effect.

[0040] In one embodiment, the self-contained noise-canceling metamaterial structure can provide air circulation between and around the fins. This allows the acoustic source to be cooled by air flowing through the metamaterial structure.

[0041] Known existing noise reduction solutions require the use of traditional sound-absorbing materials, such as porous foams, mass-loaded vinyl, sealants, and thermoplastic composites. These solutions require large amounts of material, which takes up valuable space in the application environment. This large amount of material usage is also very expensive. Traditional approaches require large amounts of sound-blocking and / or sound-absorbing materials, which are expensive and take up valuable real estate. Furthermore, the use of traditional materials also has limitations in terms of performance effectiveness.

[0042] Figure 10 is a 2D diagram of an example acoustic metamaterial fin structure 1000 for noise cancellation according to certain embodiments. The acoustic metamaterial structure 1000 includes a plurality of metamaterial fin components 1010 surrounding a sound source 1020, wherein each metamaterial fin component 1010 may have the Figure 3-9 In one embodiment, the metamaterial fin components 1010 can be substantially identical. For example, each metamaterial fin component 1010 includes a plurality of fins 1015 separated by air layers, wherein the fin spacing, width, fin thickness, and number of fins depend on the characteristics of the sound source 1020, the desired cancellation level, and similar characteristics and / or requirements. Figure 10 In the illustrated geometry, four of the metamaterial fin components 1010 surround or enclose (or substantially surround or enclose) a sound source 1020 . Figure 11 The simulated 2D sound field or model 1100 of a reference monopole point source shows a uniform sound pressure level distribution of a 4kHz sound source. As shown in the figure, the sound pressure level (SPL) at 0.5 meters is approximately 100dB in all directions. Figure 12 is an example acoustic metamaterial fin structure (such as Figure 10 1000). This acoustic field or model 1200 is relative to a 4 kHz sound source. As shown, the acoustic metamaterial fin structure 1000 reduces the sound pressure level to approximately 55 dB in all directions.

[0043] Figure 13 is a perspective view 1300 of a metamaterial fin component 1310 of an example 3D acoustic metamaterial fin structure for sound cancellation according to some embodiments, such as Figure 14 or Figure 15As shown. The metamaterial fin component 1310 has a fin spacing, a fin width (or length), a fin thickness, and a number of fins, wherein the fin spacing, fin width (or length), fin thickness, and fin number depend on the characteristics and geometry of the sound source, the desired cancellation level, and similar characteristics and / or requirements. In one embodiment, the metamaterial fin components 1310 can be substantially the same. In one embodiment, the width 1330 and length 1340 of each fin 1320 have the same value. In one embodiment, the fins 1320 are connected to each other by a center beam 1325. In one embodiment, the fins 1320 are connected to each other by a skeleton support structure. In one embodiment, a noise reduction material such as foam can be used to connect the fins 1320 to each other. The air space between the fins and the fin components can be filled with foam that connects the fins and the fin components together. In addition, the foam can provide sound absorption performance over a wider spectrum, wherein the fin components can be concentrated on resonant frequencies with higher amplitudes. Other connection techniques can be used without departing from the scope of the specification and claims.

[0044] Figure 14 is a perspective view 1400 of four metamaterial fin components 1410 of an example 3D acoustic metamaterial fin structure for sound cancellation according to certain embodiments, such as Figure 14 or Figure 15 As shown. Each metamaterial fin component 1410 has a fin pitch, fin width (or length), fin thickness, and number of fins, which may depend on the characteristics and / or geometry of the sound source, the desired cancellation level, and similar characteristics and / or requirements. In one embodiment, the metamaterial fin components 1410 may be substantially identical. In one embodiment, the width 1430 and length 1440 of each fin 1420 have the same value. Although not shown, the fins 1420 may be configured as described for the embodiment of the present invention. Figure 13 The interconnection is achieved as described.

[0045] Figure 15 is a perspective view of six metamaterial fin components 1510 of an example 3D acoustic metamaterial fin structure 1500 for sound cancellation in accordance with certain embodiments. Each fin metamaterial component 1510 has a fin pitch, a fin width (or length), a fin thickness, and a number of fins, the fin pitch, fin width (or length), fin thickness, and number of fins depending on the characteristics and / or geometry of the sound source, the desired cancellation level, and similar characteristics and / or requirements. In one embodiment, the metamaterial fin components 1510 can be substantially identical. In one embodiment, the width 1530 and length 1540 of each fin 1520 have the same value. Although not shown, the fins 1520 can be configured as described for the example 3D acoustic metamaterial fin structure 1500. Figure 13The interconnection is achieved as described.

[0046] Figure 16 16 is a cross-sectional diagram of a 3D reference monopole source showing a simulated sound field or model 1600. As shown, the sound pressure level is substantially consistent at about or near 100-120 dB. Figure 17 is a simulated sound field or model 1700 shown in a cross-sectional view of a 3D acoustic metamaterial structure for sound cancellation according to certain embodiments, e.g. Figure 15 3D acoustic metamaterial structure. As shown in the figure, the reduction in sound pressure level is consistent at around 80dB.

[0047] In operation, a set of metamaterial fin elements are arranged to substantially surround a sound source. In one embodiment, the metamaterial fin elements are arranged symmetrically around the sound source. Sound emitted from the sound source encounters the metamaterial fin elements. Due to the symmetry of the metamaterial fin elements and their orientation, each metamaterial fin element reflects the sound back. As a result, the reflections are canceled out, and the noise is eliminated.

[0048] Figure 18 18 is a flow chart of an example method 1800 for providing an acoustic metamaterial fin component according to certain embodiments. The method includes: determining 1810 a number of fins of different sizes made of a material that is very dense relative to the density of air; determining 1820 a fin pitch; determining 1830 a fin width (or length); determining 1840 a fin thickness; forming 1850 the determined number of fins; and 1860 arranging the number of fins perpendicularly from a sound source, wherein the fin with the smallest width (or length) is located closest to the sound source.

[0049] Method 1800 includes determining 1810 the number of fins of different sizes made of a material that is very dense relative to the density of air, determining 1820 the fin spacing, determining 1830 the fin width (or length), and determining 1840 the fin thickness. Each fin is wider and longer in a direction perpendicular to the sound source. The size and number of fins can depend on the frequency of interest, the wavelength of interest, the characteristics of the sound source, etc. In one embodiment, the acoustic metamaterial is brass, whose anisotropic properties are controlled by varying the bulk modulus and / or mass density.

[0050] The method 1800 includes forming the determined number of fins at 1850. Each fin is formed using a fin width (or length) and a fin thickness.

[0051] Method 1800 includes arranging a determined number of fins perpendicularly from a sound source at 1860, wherein the smallest of the fins is closest to the sound source. Each fin is symmetrically positioned about a line drawn from the sound source. Sound emitted from the sound source is amplified and reflected back to the sound source. In one embodiment, the amplification is due to the superposition of multiple in-phase redirections of the sound wave through each fin.

[0052] Figure 19 19 is a flow chart of an example method 1900 for providing an acoustic metamaterial fin structure comprised of a defined number of metamaterial fin elements, according to certain embodiments. The method includes: forming 1910 a plurality of acoustic metamaterial fin elements; and arranging 1920 the plurality of acoustic metamaterial fin elements perpendicularly from a sound source to substantially surround the sound source. For example, example method 1900 provides a self-capacitive noise-canceling metamaterial structure using fin elements having fins made of a material that is very dense relative to the density of air.

[0053] Method 1900 includes providing 1910 a plurality of acoustic metamaterial fin components. The acoustic metamaterial fin components are substantially the same or identical in size and are comprised of fins made of a material that is very dense relative to the density of air, wherein each fin is wider (or longer) in a perpendicular direction away from the sound source. The number of acoustic metamaterial fin components may depend on the frequencies of interest, the wavelengths of interest, the sound source characteristics, the sound cancellation characteristics, etc. In one embodiment, the fin material is brass, which controls the anisotropic properties of the metamaterial fin components by varying the bulk modulus and / or mass density in different directions through the pyramidal fin components. In one embodiment, each fin component represents a pyramidal structure. In one embodiment, the acoustic metamaterial fin component uses Figure 18 Method 1800.

[0054] Method 1900 includes arranging, at 1920, a plurality of acoustic metamaterial fin components perpendicularly from a sound source to substantially surround the sound source, such that the smallest fins in the acoustic metamaterial fin components are closest to the sound source. In one embodiment, the acoustic metamaterial fin components are symmetrically positioned about a line drawn perpendicularly from the sound source. Due to destructive interference of reflected sound waves between each acoustic metamaterial fin component within the metamaterial structure, sound emanating from the sound source is canceled.

[0055] The construction and arrangement of the method shown in various exemplary embodiments are only illustrative. Although only several embodiments are described in detail in the present invention, many modifications are possible (for example, the size, dimensions, structure, shape and ratio of various elements, parameter values, installation forms, use of materials and components, color, orientation, etc.). For example, the position of the element can be reversed or otherwise changed, and the property or quantity or position of the individual elements can be changed or varied. Therefore, all these modifications are intended to be included within the scope of the present invention. The order or sequence of any process or method step can be changed or reordered according to alternative embodiments. Without departing from the scope of the present invention, other substitutions, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments.

[0056] Although the accompanying drawings may show a specific order of method steps, the order of the steps may vary from that depicted. Furthermore, two or more steps may be performed simultaneously or partially simultaneously. Such variations will depend on the software and hardware systems selected and the designer's preferences. All such variations are within the scope of the present invention. Similarly, software implementation can be accomplished using standard programming techniques with rule-based logic and other logic to accomplish the various connection steps, processing steps, comparison steps, and decision steps.

[0057] While the invention has been described in conjunction with certain embodiments, it should be understood that the invention is not limited to the disclosed embodiments, but on the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the purview of the appended claims, the scope of which is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.

Claims

1. A noise cancellation device, comprising: An acoustic metamaterial device configured for use with an acoustic source, comprising: Multiple fins, and a plurality of fin members, each fin member comprising a group of the plurality of fins, wherein each fin is made of brass, said brass producing anisotropic properties of said acoustic metamaterial device, wherein each fin has a length dimension, a width dimension, and a thickness dimension, the width dimension and the length dimension being equal and substantially perpendicular to the direction of propagation of sound waves from the sound source, Wherein along the width dimension and the length dimension, each fin has a different size from other fins, wherein the plurality of fins are connected to each other so that a plane formed by the width dimension and the length dimension of each fin is perpendicular to the propagation direction of the sound wave from the sound source, The thickness of each of the plurality of fins is the same. The fin with the smallest volume is closest to the sound source.

2. The noise cancellation device according to claim 1, wherein The length dimension and the width dimension depend on at least one of the frequency of interest, the wavelength of interest, the desired amplification, the desired directionality, and the size and characteristics of the sound source.

3. The noise cancellation device according to claim 2, wherein The thickness dimension depends on at least one of the frequency of interest, the wavelength of interest, the desired amplification, the desired directionality, and the size and characteristics of the sound source.

4. The noise cancellation device according to claim 3, wherein The fin spacing depends on at least one of the frequency of interest, the wavelength of interest, the desired amplification, the desired directionality, and the size and characteristics of the sound source.

5. The noise cancellation device according to claim 4, wherein The number of fins depends on at least one of the frequency of interest, the wavelength of interest, the desired amplification, the desired directionality, and the size and characteristics of the sound source.

6. The noise cancellation device according to claim 1, wherein The length dimension and the width dimension depend on at least one of the frequency of interest, the wavelength of interest, the desired amplification, the desired directionality, and the size and characteristics of the sound source.

7. The noise cancellation device according to claim 6, wherein The number of fin members depends on at least one of the frequency of interest, the wavelength of interest, the desired amplification, the desired directionality, and the size and characteristics of the sound source.

8. A method for manufacturing a noise cancellation device including an acoustic metamaterial device, the method comprising: Multiple fins are formed from brass, which defines the anisotropy of the device. wherein each fin has a different volume defined by a length dimension, a width dimension, and a thickness dimension, and Wherein along the width dimension and the length dimension, each fin has a different size from other fins, forming a plurality of fin members, each fin member including a set of the plurality of fins; arranging the plurality of fin members vertically from a sound source to substantially surround the sound source, wherein the plurality of fins are connected to each other such that planes formed by the length dimension and the width dimension of each fin are substantially parallel; and Arranging the plurality of fins so that a plane formed by a length dimension and a width dimension of each fin is perpendicular to a direction of propagation of sound waves from a sound source; wherein each of the plurality of fins has the same thickness, and The fin with the smallest volume is closest to the sound source.

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