Vibration sensor and microphone

Abstract

The vibration sensor and the microphone provided by the present specification fix both ends of a vibration beam on a base, and the middle part is suspended in a cavity and generates deformation in response to external vibration excitation. The vibration sensor and the microphone change the structure and size of the cavity and the size and position of the vibration beam, so that the size of the part suspended in the cavity of the plurality of vibration beams is different, so that different vibration beams have different natural frequencies, generate resonance peaks of different frequencies under vibration excitation, and have a wider frequency response range. At the same time, the vibration sensor and the microphone select the vibration signal in the preset range near the resonance peak, and have higher sensitivity. Moreover, the vibration sensor and the microphone realize the purpose of multiple resonance peaks and wide frequency band by designing the size of the base cavity, which has simple structure, low processing difficulty, low processing cost, higher precision, and more accurate vibration signal collection results.

Description

Technical Field

[0001] This specification relates to the field of sensors, and more particularly to a vibration sensor and a microphone. Background Technology

[0002] In existing technologies, vibration sensors such as accelerometers, loudspeakers, gyroscopes, energy harvesters, bone conduction microphones, and air conduction microphones widely employ diaphragm and mass block structures or cantilever beam and mass block structures. For example, microphones use diaphragm and mass block structures or cantilever beam and mass block structures in vibration sensors to receive external vibration excitations, convert the vibration excitations into electrical signals, process them through back-end circuitry, and output electrical signals to collect sound signals. Air conduction microphones can collect air vibrations caused by a user emitting sound and convert the air vibrations into electrical signals. Bone conduction microphones can collect mechanical vibrations of bones and skin caused by a user speaking and convert the mechanical vibrations into electrical signals. Higher sensitivity and a wider frequency response range to vibration excitations have always been the goals pursued by vibration sensors. However, due to the characteristics of vibration systems, the sensitivity decreases sharply after the resonance peak, and the higher the resonance frequency, the lower the sensitivity generally is. This makes it difficult for single-resonance-peak vibration sensors to simultaneously achieve both high sensitivity and wide bandwidth. At the same time, a single resonance peak often cannot meet the requirements. Existing multi-resonance-peak vibration sensors have complex structures and are difficult to manufacture, resulting in higher costs and lower accuracy.

[0003] Therefore, there is a need to provide a vibration sensor and microphone with a wider frequency response range, higher sensitivity, and simpler structure. Summary of the Invention

[0004] This manual provides a vibration sensor and microphone that have a wider frequency response range, higher sensitivity, and simpler structure.

[0005] In a first aspect, this specification provides a vibration sensor, including a base and a plurality of vibration beams. The base includes a cavity. The plurality of vibration beams are arranged sequentially on the base, wherein each vibration beam includes a fixed end and a movable end. The fixed end is located at both ends of the vibration beam and connected to the base. The movable end is connected to the fixed end and located between the fixed ends, suspended in the cavity. Each vibration beam has a different size suspended in the cavity and has a different natural frequency. Each vibration beam responds to external vibration excitation and generates a vibration signal within a sub-target frequency window, including its corresponding natural frequency.

[0006] In some embodiments, the multiple sub-target frequency windows corresponding to the multiple vibration beams cover different frequency ranges, and the multiple sub-target frequency windows constitute a target frequency window.

[0007] In some embodiments, the multiple natural frequencies corresponding to the multiple vibrating beams are uniformly distributed within the target frequency window.

[0008] In some embodiments, the dimensions of the cavity in the first direction vary along the second direction, the plurality of vibrating beams are arranged on the base along the second direction, and the fixed end is connected to the base along the first direction.

[0009] In some embodiments, the dimensions of the cavity in the first direction, the position of each vibrating beam on the cavity, and the dimensions of each vibrating beam satisfy a preset rule, such that the natural frequency of each vibrating beam satisfies a preset value.

[0010] In some embodiments, the mobile terminal deforms in response to the vibration excitation. The mobile terminal includes a piezoelectric sensing component and a connecting beam. The piezoelectric sensing component converts the deformation into the vibration signal, which includes an electrical signal. The connecting beam is connected to the piezoelectric sensing component.

[0011] In some embodiments, the distance between the piezoelectric sensing element and one of the fixed ends is in the range of one-quarter to three-quarters of the length of the moving end.

[0012] In some embodiments, the mobile end includes two piezoelectric sensing components, respectively located near the two ends of the fixed end, and the distance between each piezoelectric sensing component and the fixed end it is near is less than 1 / 4 of the length of the mobile end.

[0013] In some embodiments, the piezoelectric sensing component includes at least one of a piezoelectric single-crystal structure and a piezoelectric dual-crystal structure.

[0014] In some embodiments, each vibrating beam further includes a counterweight connected to the movable end, wherein the movable end deforms in response to the vibration excitation, and the counterweight generates displacement based on the deformation.

[0015] In some embodiments, the dimensions of the cavity in the first direction, the position of each vibrating beam on the cavity, the dimensions of each vibrating beam, and the dimensions of the counterweight satisfy a preset rule, such that the natural frequency of each vibrating beam satisfies a preset value.

[0016] In some embodiments, the size of the counterweight is matched with the natural frequency of its corresponding vibrating beam, such that the deviation of the vibration signal of the plurality of vibrating beams at their corresponding natural frequencies is within a preset deviation range.

[0017] Secondly, this specification also provides a microphone, including a housing, a vibration sensor as described in the first aspect of this specification, and a signal synthesis circuit. The vibration sensor is installed in the housing, and the base is fixedly connected to the housing. The signal synthesis circuit is connected to the plurality of vibration beams, and during operation, it collects the vibration signal and performs signal synthesis processing on the vibration signal to generate a vibration signal within a target frequency window. The plurality of sub-target frequency windows corresponding to the plurality of vibration beams cover different frequency ranges, and the plurality of sub-target frequency windows constitute the target frequency window.

[0018] As can be seen from the above technical solution, the vibration sensor and microphone provided in this specification fix both ends of the vibration beam to the base, while the middle part is suspended in the cavity and deforms in response to external vibration excitation. By changing the structure and size of the cavity and the size and position of the vibration beam, the vibration sensor and microphone allow for different sizes of the suspended portions of multiple vibration beams, resulting in different natural frequencies for each beam, generating resonance peaks of different frequencies under vibration excitation. Multiple vibration beams can generate vibration signals within multiple frequency ranges, which together constitute a wideband vibration signal, thus widening the frequency response range of the vibration sensor. Furthermore, the vibration sensor and microphone select vibration signals within a preset range near the resonance peak, resulting in higher sensitivity. Moreover, the vibration sensor and microphone achieve multiple resonance peaks and a wideband by designing the dimensions of the base cavity, resulting in a simple structure, low manufacturing difficulty, low manufacturing cost, higher precision, and more accurate vibration signal acquisition results.

[0019] Other functions of the vibration sensor and microphone provided in this specification will be partially listed in the following description. The figures and examples described below will be readily apparent to those skilled in the art. The inventive aspects of the vibration sensor and microphone provided in this specification can be fully understood through practice or use of the methods, apparatus, and combinations described in the detailed examples below. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this specification, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A side view of a vibration sensor provided according to an embodiment of this specification is shown;

[0022] Figure 2 A front view of a vibration sensor provided according to an embodiment of this specification is shown;

[0023] Figure 3 A top view of a vibration sensor provided according to an embodiment of this specification is shown;

[0024] Figure 4 A right view of a vibration sensor provided according to an embodiment of this specification is shown;

[0025] Figure 5 It shows Figure 2 AA (Cross-section view);

[0026] Figure 6 A schematic diagram of a piezoelectric single crystal structure provided according to an embodiment of this specification is shown;

[0027] Figure 7 A schematic diagram of a piezoelectric bicrystalline structure provided according to an embodiment of this specification is shown;

[0028] Figure 8 A normalized displacement resonance curve is shown according to an embodiment of this specification; and

[0029] Figure 9 A schematic diagram of a vibration signal provided according to an embodiment of this specification is shown. Detailed Implementation

[0030] The following description provides specific application scenarios and requirements for this specification, intended to enable those skilled in the art to make and use the contents of this specification. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of this specification. Therefore, this specification is not limited to the embodiments shown, but rather to the widest scope consistent with the claims.

[0031] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not restrictive. For example, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” used herein may also include the plural forms. When used in this specification, the terms “comprising,” “including,” and / or “containing” mean that the associated integers, steps, operations, elements, and / or components are present, but do not exclude the presence of one or more other features, integers, steps, operations, elements, components, and / or groups, or that other features, integers, steps, operations, elements, components, and / or groups may be added to the system / method.

[0032] Considering the following description, these and other features of this specification, as well as the operation and function of the related components of the structure, and the economy of assembly and manufacture of the parts, can be significantly improved. All of these form part of this specification with reference to the accompanying drawings. However, it should be clearly understood that the drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of this specification. It should also be understood that the drawings are not drawn to scale.

[0033] It should be understood that, for the convenience of describing this specification, the positional relationships indicated by terms such as "center," "upper surface," "lower surface," "upper," "lower," "top," "bottom," "inner," "outer," "axial," "radial," "outer periphery," and "external" are based on the positional relationships shown in the accompanying drawings, and do not indicate that the device, component, or unit referred to must have a specific positional relationship, and should not be construed as a limitation of this specification.

[0034] It should be understood that the terms “system,” “device,” “unit,” and / or “module” used herein are one way to distinguish different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0035] The flowcharts used in this specification illustrate operations implemented according to some embodiments of this specification. It should be clearly understood that the operations in the flowcharts may not be implemented in a sequential order. Instead, the operations may be implemented in reverse order or simultaneously. Furthermore, one or more additional operations may be added to the flowcharts. One or more operations may be removed from the flowcharts.

[0036] For ease of understanding, this manual first explains the terms that will appear in the following description as follows:

[0037] Sensitivity: The ratio of the output signal to the input signal. For vibration sensors, the input signal can be an external vibration excitation, and the output signal can be an electrical signal generated in response to the vibration excitation. The sensitivity of a vibration sensor refers to the ratio of the output electrical signal to the input vibration excitation. The output electrical signal can be converted into the amplitude of the vibration signal; therefore, the sensitivity of a vibration sensor can also be understood as the ratio of the amplitude of the output vibration signal to the amplitude of the input vibration excitation. When the dimensions of the output signal and the input signal are the same, the sensitivity can be understood as the amplification factor of the input signal. Higher sensitivity indicates better acquisition performance of the vibration sensor for minute vibration excitations.

[0038] Resonance: Also known as "resonance," it is the phenomenon where, under the influence of periodic external vibration excitation, the amplitude of a vibrating system increases sharply when the frequency of the external vibration excitation is the same as or very close to the system's natural vibration frequency. The frequency at which resonance occurs is called the "resonant frequency."

[0039] Resonance peak: The peak value of the resonant frequency.

[0040] The vibration sensor and microphone provided in this specification can be used to collect external vibration excitations and convert them into electrical signals. The vibration sensor and microphone can be used not only to collect vibration excitations caused by air vibrations but also by mechanical vibrations, such as bone vibrations and skin vibrations when a person speaks. The vibration sensor and microphone can be used not only as air conduction microphones but also as bone conduction microphones.

[0041] Figure 1 A side view of a vibration sensor 001 provided according to an embodiment of this specification is shown; Figure 2 A front view of a vibration sensor 001 provided according to an embodiment of this specification is shown; Figure 3 A top view of a vibration sensor 001 provided according to an embodiment of this specification is shown; Figure 4 A right view of a vibration sensor 001 provided according to an embodiment of this specification is shown; Figure 5 It shows Figure 2 Cross-sectional view AA. (See diagram AA.) Figures 1 to 5 As shown, the vibration sensor 001 may include a base 200 and multiple vibration beams 400.

[0042] The base 200 can be the mounting base for the vibration sensor 001. Other components of the vibration sensor 001, such as the vibration beam 400, can be directly or indirectly connected to the base 200. The connection can be any method, such as welding, riveting, snap-fitting, bolting, or other fixed connections, or connections deposited through physical deposition (e.g., physical vapor deposition) or chemical deposition (e.g., chemical vapor deposition). The base 200 can be a structure of any shape, such as a cube, cuboid, cylinder, prism, frustum, or any irregularly shaped structure. The material of the base 200 can be Si, SiO2, SiNx, etc. In some embodiments, the base 200 may include a cavity 220. In some embodiments, the cavity 220 may penetrate the base 200. In some embodiments, the cavity 220 may not penetrate the base 200. Figures 1 to 5 As illustrated in the example, cavity 220 may extend through the upper and lower surfaces of base 200.

[0043] In some embodiments, the cavity 220 may be a single unit. In some embodiments, the cavity 220 may include a plurality of spaced sub-cavities. For ease of description, Figures 1 to 5The cavity 220 shown is a single unit. Those skilled in the art will understand that the cavity 220 may include multiple spaced sub-cavities, which are also within the scope of this specification.

[0044] The dimensions of the cavity 220 in the first direction 221 can vary along the second direction. That is, the dimensions of the cavity 220 in the first direction 221 change with its position in the second direction 222. In other words, the dimensions of the cavity 220 in the first direction 221 are different at different positions in the second direction 222. The first direction 221 and the second direction 222 are not the same direction. That is, the first direction 221 and the second direction 222 form a certain angle. The angle can be acute, right, or obtuse. In some embodiments, the first direction 221 and the second direction 222 are perpendicular. The cross-sectional shape of the cavity 220 can be any shape that satisfies the above conditions, such as a circle, ellipse, quadrilateral, pentagon, hexagon, heptagon, octagon, or even an irregular shape, such as a curve with varying curvature, etc. Different shaped cavities 220 may have different corresponding first directions 221 and second directions 222. In some embodiments, the cross-sectional shape of the cavity 220 can be a quadrilateral, such as a square, where the first direction 221 can be the direction of one diagonal of the square, and the second direction 222 can be the direction of the other diagonal of the square. In some embodiments, the cross-sectional shape of the cavity 220 can be a rectangle, where the first direction 221 can be a direction forming an acute angle with the length or width of the rectangle, and the second direction 222 can be a direction perpendicular to the first direction. In some embodiments, the cross-section of the cavity 220 can be a parallelogram, where the first direction 221 can be a direction forming an acute angle with one side of the parallelogram, and the second direction 222 can be a direction perpendicular to the first direction. In some embodiments, the cross-section of the cavity 220 can be a trapezoid, such as an isosceles trapezoid, where the second direction 222 can be the height direction of the isosceles trapezoid, and the first direction 221 can be a direction perpendicular to the second direction 222. In some embodiments, the second direction 222 can also be a direction forming an acute angle with the height direction of the isosceles trapezoid, and the first direction 221 can be a direction perpendicular to the second direction 222. In some embodiments, the cross-section of the cavity 220 can also be a right trapezoid, the second direction 222 can be the height direction of the right trapezoid, and the first direction 221 can be a direction perpendicular to the second direction 222. In some embodiments, the cross-section of the cavity 220 can also be other quadrilaterals, such as trapezoids of shapes other than isosceles trapezoids and right trapezoids, such as rhombuses, irregular quadrilaterals, etc. In some embodiments, the cross-section of the cavity 220 can be circular, the first direction 221 can be any diameter direction, and the second direction 222 can be a direction perpendicular to the first direction 221.In some embodiments, the cross-section of the cavity 220 may be elliptical, the first direction 221 may be the direction of the major axis or the minor axis of the ellipse, and the second direction 222 may be a direction perpendicular to the first direction.

[0045] Figures 1 to 5 The cavity 220 shown has an isosceles trapezoidal cross-section, where the second direction 222 is the height direction of the isosceles trapezoid, and the first direction 221 is perpendicular to the second direction 222. The dimensions of the cavity 220 in the first direction 221 differ depending on its position in the second direction 222. Those skilled in the art should understand that other shapes of the cavity 220 that satisfy the above conditions are also within the scope of this specification.

[0046] The edge of cavity 220 can be straight, curved, serrated, etc. In some embodiments, the edge of cavity 220 can be straight. The size of cavity 220 can be designed based on the application scenario of vibration sensor 001 and the requirements for vibration excitation. For example, the size of cavity 220 may be different when vibration sensor 001 is used as an accelerometer and when it is used as an air conduction microphone. In some embodiments, the size of cavity 220 may be related to the size of vibration beam 400, which will be described in detail later.

[0047] like Figures 1 to 5 As shown, the vibration sensor 001 may include multiple vibration beams 400. The vibration beams 400 may be connected to the base 200 and deform in response to external vibration excitation, converting the deformation into a vibration signal. In some embodiments, the vibration signal may be an electrical signal. The vibration excitation may be an air vibration excitation acting directly on the vibration beams 400, or a mechanical vibration excitation acting on the base 200. The vibration beams 400 may be plate-like structures of any shape. For example, their shape may be a rectangular beam, a trapezoidal beam, an L-shaped beam, or other shapes, such as a curved shape, etc. Multiple vibration beams 400 may be arranged sequentially on the base 200 along the second direction 222. In some embodiments, the vibration beams 400 may be fixed beams, meaning that both ends of the vibration beams 400 may be connected to the base 200, while the middle portion may be suspended on the cavity 220. Specifically, each vibration beam 400 may include a fixed end 420 and a movable end 440. In some embodiments, each vibration beam 400 may also include a counterweight 460.

[0048] The fixed ends 420 can be located at both ends of the vibrating beam 400. The fixed ends 420 can be connected to the base 200 along the first direction 221. That is, the two ends of the fixed ends 420 can be distributed along the first direction 221. For ease of description, we define the direction in which the two ends of the fixed ends 420 are distributed as the length direction or axial direction of the vibrating beam 400. The connection between the fixed ends 420 and the base 200 can be any connection method, such as welding, riveting, snap-fitting, bolting, or other fixed connection methods, or a deposition connection through physical deposition (e.g., physical vapor deposition) or chemical deposition (e.g., chemical vapor deposition). The fixed ends 420 and the base 200 can be insulated; for example, the fixed ends 420 are connected to the base 200 through an insulating layer. The material of the fixed ends 420 can be Si, SiO2, SiNx, etc.

[0049] In some embodiments, the fixed end 420 may be fixedly connected to the upper surface, lower surface of the base 200, or the inner wall of the cavity 220. Figures 1 to 5 The schematic diagram shown illustrates the connection between the fixed end 420 and the upper surface of the base 200 as an example. Those skilled in the art should understand that other connections between the fixed end 420 and the base 200 are also within the scope of this specification.

[0050] The mobile terminal 440 can be connected to the fixed terminal 420 and is located between the fixed terminals 420, suspended within the cavity 220. "Suspended within the cavity 220" can mean that it is suspended inside, below, or above the cavity 220 of the base 200, and does not contact the base 200. For ease of demonstration, as... Figures 1 to 5 As shown, for illustrative purposes only, the mobile terminal 440 may be suspended above the cavity 220.

[0051] The mobile end 420 can deform in response to the vibration excitation and convert the deformation into a vibration signal. In some embodiments, the mobile end 440 may include a piezoelectric sensing component 442 and a connecting beam 444. The piezoelectric sensing component 442 can convert the deformation of the mobile end 420 into the vibration signal, which may include an electrical signal. The connecting beam 444 may connect the piezoelectric sensing component 442.

[0052] The piezoelectric sensing component 442 may include a piezoelectric material. As previously described, the vibration sensor 001 can receive external vibration excitation and convert it into an electrical signal. Specifically, the external vibration excitation can cause deformation of the moving end 4440, which in turn causes deformation of the piezoelectric material in the piezoelectric sensing component 442, thereby generating stress and outputting a voltage, thus converting the external vibration excitation into an electrical signal. This signal is then acquired and conditioned by the back-end circuit to obtain the desired electrical signal. All piezoelectric materials conform to the piezoelectric effect constitutive equation. For the vibration sensor 001, the direct piezoelectric effect is applied, and its constitutive equation is:

[0053]

[0054] Where, d ij T is the piezoelectric strain coefficient. j For stress, E is the dielectric constant under constant force. j Let D be the electric field strength. i For vibration sensor 001, the electrical displacement D is the electric displacement. i This is mainly caused by stress generated by external vibration excitation. The constitutive equation can be further simplified to:

[0055] D i =d ij T j

[0056] From the above formula, it can be seen that the output electric displacement D of the piezoelectric material i The magnitude depends on the material's own piezoelectric strain coefficient d ij And the stress T generated by the piezoelectric material during operation j After determining the piezoelectric material, increasing the stress in the effective piezoelectric material area through structural design is an effective measure to improve the output of the piezoelectric sensing component 442.

[0057] The piezoelectric sensing component 442 can be suspended within the cavity 220. In some embodiments, the piezoelectric sensing component 442 can be distributed across all areas of the movable end 440. In some embodiments, the piezoelectric sensing component 442 can also be distributed across a portion of the movable end 440. The piezoelectric sensing component 442 can convert the deformation of the movable end 440 into a vibration signal and output it. When relative movement occurs between the movable end 440 and the base 200, the degree of deformation varies at different locations of the movable end 440, resulting in different deformation stresses on the piezoelectric sensing component 442. To improve the sensitivity of the vibration sensor 001, in some embodiments, the piezoelectric sensing component 442 can be positioned only at locations of higher deformation and stress on the movable end 440, thereby improving the sensitivity of the vibration sensor 001. For ease of description, we define the locations of higher deformation and stress on the movable end 440 as a first region, and the locations of lower deformation and stress on the movable end 440 as a second region. The voltage of the electrical signal in the first region is higher than that in the second region. In some embodiments, the piezoelectric sensing component 442 may be disposed only in the first region. It should be noted that the first region and the second region refer to the region corresponding to the moving end 440, excluding the region of the fixed end 420, that is, the region at the connection between the vibrating beam 400 and the base 200.

[0058] The direction of the stress borne by the moving end 440 is related to the overall deformation direction of the moving end 440. When the moving end 440 vibrates downwards and upwards, its deformation direction is opposite. At this time, the stress direction borne by the same part of the moving end 440 is also opposite. The area subjected to compressive stress in upward vibration will be subjected to tensile stress in downward vibration, and the area subjected to tensile stress in upward vibration will be subjected to compressive stress in downward vibration. For example, when the moving end 440 vibrates downwards, when the moving end 440 deforms, the axial stress on the lower surface of the moving end 440 is symmetrical about the center of the moving end 440, and on the center side, the tensile stress decreases to zero, and then increases from zero to compressive stress. The zero point is located at one-quarter and three-quarters of the axial length of the moving end 440. When the moving end 440 vibrates upward, when the moving end 440 deforms, the axial stress on the lower surface of the moving end 440 is symmetrical about the center of the moving end 440, and on the center side, the compressive stress decreases to zero, and then increases from zero to tensile stress. The zero point is located at one-quarter and three-quarters of the axial length of the moving end 440.

[0059] Therefore, to improve the sensitivity of the piezoelectric sensing element 442, the piezoelectric sensing element 440 can be arranged in a region with high stress and the same stress direction. For ease of illustration, the following description uses the downward vibration of the moving end 440 as an example. When the moving end 440 vibrates downward, in some embodiments, the piezoelectric sensing element 442 can be arranged in a region with high compressive stress. For example, the piezoelectric sensing element 442 can be arranged at both ends of the moving end 440 near the fixed end 420, and within a range where the distance from the fixed end 420 is less than one-quarter of the length of the moving end 440. That is, the first region can be at both ends of the moving end 440, within a range where the distance from the fixed end 420 is less than one-quarter of the length of the moving end 440. For example, the moving end 440 can include at least two piezoelectric sensing elements 442. Taking a scenario where there are two piezoelectric sensing components 442, the two piezoelectric sensing components 442 can be located near the two ends of the fixed end 420, and the distance between each piezoelectric sensing component 442 and the fixed end 420 it is near can be less than 1 / 4 of the length of the moving end 440. In this case, the two ends of the piezoelectric sensing component 442 are connected to the fixed end 420 and the connecting beam 444, respectively.

[0060] In some embodiments, when the movable end 440 vibrates downward, the piezoelectric sensing element 442 can be arranged in a region of high tensile stress. For example, the piezoelectric sensing element 442 can be arranged on the movable end 440, and the distance between it and one end of the fixed end 420 is in the range of one-quarter to three-quarters of the length of the movable end 440. That is, the first region can be on the movable end 440, and the distance between it and one end of the fixed end 420 is in the range of one-quarter to three-quarters of the length of the movable end 440.

[0061] It should be noted that the distance between the piezoelectric sensing component 442 and the fixed end 420 can be any position on the piezoelectric sensing component 442 and the fixed end 420. For example, the distance between the piezoelectric sensing component 442 and the fixed end 420 can be the distance between the center of the piezoelectric sensing component 442 and the fixed end 420, or the distance between the end of the piezoelectric sensing component 442 (any end) and the fixed end 420, or the distance between other parts of the piezoelectric sensing component 442 and the fixed end 420.

[0062] The piezoelectric sensing component 442 may include at least one of a stacked structure composed of piezoelectric single crystal structures and a stacked structure composed of piezoelectric bicrystalline structures. In some embodiments, the piezoelectric sensing component 442 may be a stacked structure composed of piezoelectric single crystal structures. Figure 6A schematic diagram is shown of a piezoelectric sensing component 442 provided according to an embodiment of this specification, which is a piezoelectric single crystal structure 442a. In some embodiments, the piezoelectric single crystal structure 442a may, from bottom to top along the thickness direction of the piezoelectric sensing component 442, sequentially include an elastic layer 442a-2, a bottom electrode layer 442a-4, a piezoelectric layer 442a-6, and a top electrode layer 442a-8. In some embodiments, the piezoelectric single crystal structure 442a may, from top to bottom along the thickness direction of the piezoelectric sensing component 442, sequentially include an elastic layer 442a-2, a top electrode layer 442a-8, a piezoelectric layer 442a-6, and a bottom electrode layer 442a-4. For ease of illustration, we will describe it using the example where the piezoelectric single crystal structure 442a includes, from bottom to top along the thickness direction of the piezoelectric sensing component 442, an elastic layer 442a-2, a bottom electrode layer 442a-4, a piezoelectric layer 442a-6, and a top electrode layer 442a-8. In some embodiments, the piezoelectric single crystal structure 442a may further include connection terminal layers 442a-9.

[0063] The elastic layer 442a-2 can be directly or indirectly fixedly connected to the fixed end 420 and the connecting beam 444. The connection can be any method, such as welding, riveting, snap-fitting, bolting, or other fixed connections, or connections deposited through physical deposition (e.g., physical vapor deposition) or chemical deposition (e.g., chemical vapor deposition). When the vibrating beam 400 is subjected to external vibration excitation, the elastic layer 442a-2 deforms based on the vibration excitation. The elastic layer 442a-2 is made of a material that easily deforms under external force. The elastic layer 442a-2 can be a deformable structure made of semiconductor material. The elastic layer 442a-2 can be a single-layer material, such as Si, SiO2, SiNx, SiC, etc., or a multi-layer material, such as Si / SiO2, SiO2 / Si, Si / SiNx, SiNx / Si, etc. The thickness of the elastic layer 442a-2 can be 1µm-10µm. In some embodiments, the thickness of the elastic layer 442a-2 can be 1µm-3µm. In some embodiments, the thickness of the elastic layer 442a-2 can be 2um-6um. In some embodiments, the thickness of the elastic layer 442a-2 can be 4um-8um. In some embodiments, the thickness of the elastic layer 442a-2 can be 6um-10um.

[0064] The piezoelectric sensing component 442 may include a piezoelectric layer 442a-6. The piezoelectric layer 442a-6 is a structure that can generate a voltage at its two end faces when subjected to an external force. The piezoelectric layer 442a-6 can be directly or indirectly fixedly connected to the base 200. The connection can be any connection method, such as welding, riveting, snap-fitting, bolting, or other fixed connections, or connections deposited through physical deposition (e.g., physical vapor deposition) or chemical deposition (e.g., chemical vapor deposition). In some embodiments, the piezoelectric layer 442a-6 can undergo deformation when subjected to a vibration signal and generate a voltage based on the deformation.

[0065] The piezoelectric layer 442a-6 can be directly or indirectly attached to the surface of the elastic layer 442a-2. In some embodiments, the elastic layer 442a-2 can be connected to the fixed end 420 and the connecting beam 444, and the piezoelectric layer 442a-6 is connected to the fixed end 420 and the connecting beam 444 through the elastic layer 442a-2. Taking the vibrating beam 400 located on the upper surface of the base 200 as an example, in some embodiments, the piezoelectric layer 442a-6 can be located on the side of the elastic layer 442a-2 away from the base 200. In some embodiments, the piezoelectric layer 442a-6 can be located on the side of the elastic layer 442a-2 closer to the base 200. When the vibrating beam 400 is subjected to external vibration excitation, the elastic layer 442a-2 generates the deformation based on the vibration excitation; the piezoelectric layer 442a-6 can generate a voltage (potential difference) under stress under the deformation of the elastic layer 442a-2 based on the piezoelectric effect.

[0066] For beam structures undergoing bending deformation, including cantilever beams, simply supported beams, and fixed beams, a neutral layer exists along the thickness direction when first-order bending deformation occurs. The materials on both sides of the neutral layer are under opposite stress states. For example, when a fixed beam bends upward, the material of the supporting arm above the neutral layer is under tensile stress, while the material of the supporting arm below the neutral layer is under compressive stress. The sign of the output electrical signal from the piezoelectric material is related to the stress state. To maximize the output efficiency of the piezoelectric material, the piezoelectric layer 442a-6 needs to be arranged on one side of the neutral layer.

[0067] The magnitude of the electrical signal output by the piezoelectric material is related to the magnitude of the stress. The distribution position of each layer of material in the thickness direction affects the stress distribution of each layer under the same vibration excitation. In some embodiments, the piezoelectric layer 442a-6 is distributed on one side of the elastic layer 442a-2. Specifically, the piezoelectric layer 442a-6 is distributed near the upper or lower surface of the vibrating beam 400 in the thickness direction, so that the piezoelectric layer 442a-6 is far away from the neutral layer, maximizing the stress magnitude of the piezoelectric layer 442a-6.

[0068] In some embodiments, the piezoelectric layer 442a-6 may be a piezoelectric polymer film obtained by semiconductor deposition processes (e.g., magnetron sputtering, MOCVD). In some embodiments, the material of the piezoelectric layer 442a-6 may include piezoelectric crystal materials and piezoelectric ceramic materials. A piezoelectric crystal refers to a piezoelectric single crystal. In some embodiments, piezoelectric crystal materials may include quartz, zincblende, borate, tourmaline, zincite, GaAs, barium titanate and its derived crystal structures, KH2PO4, NaKC4H4O6·4H2O (Roxi salt), etc., or any combination thereof. A piezoelectric ceramic material refers to a piezoelectric polycrystalline material formed by the random aggregation of fine grains obtained through solid-state reactions and sintering between powders of different materials. In some embodiments, piezoelectric ceramic materials may include barium titanate (BT), lead zirconate titanate (PZT), lithium lead barium niobate (PBLN), modified lead titanate (PT), aluminum nitride (AlN), zinc oxide (ZnO), or any combination thereof. In some embodiments, the material of the piezoelectric layer 442a-6 may also be a piezoelectric polymer material, such as polyvinylidene fluoride (PVDF). In some embodiments, the thickness of the piezoelectric layer 442a-6 may be greater than 500 nm. In some embodiments, the thickness of the piezoelectric layer 442a-6 may be 20-500 μm, for example when the vibration sensor 001 is used in a macroscopic device. In some embodiments, the thickness of the piezoelectric layer 442a-6 may be 0.5-1.5 μm, for example when the vibration sensor 001 is used in a MEMS device.

[0069] In some embodiments, the ratio of the thickness of the elastic layer 442a-2 to the thickness of the piezoelectric layer 442a-6 can be 1-10. In some embodiments, the ratio of the thickness of the elastic layer 442a-2 to the thickness of the piezoelectric layer 442a-6 can be 2-7.

[0070] Bottom electrode layer 442a-4 and top electrode layer 442a-8 are respectively distributed on both sides of the piezoelectric layer 442a-6. The piezoelectric layer 442a-6 can be located between the bottom electrode layer 442a-4 and the top electrode layer 442a-8. Under external vibration excitation, the piezoelectric layer 442a-6 deforms along with the elastic layer 442a-2, generating a voltage under deformation stress. The bottom electrode layer 442a-4 and the top electrode layer 442a-8 can collect this voltage to generate the electrical signal. The bottom electrode layer 442a-4 and the top electrode layer 442a-8 are aligned. As mentioned above, the piezoelectric layer 442a-6 is connected to the elastic layer 442a-2, and is distributed on one side of the elastic layer 442a-2. The bottom electrode layer 442a-4 can be distributed between the piezoelectric layer 442a-6 and the elastic layer 442a-2, and the top electrode layer 442a-8 is distributed on the side of the piezoelectric layer 442a-6 away from the elastic layer 442a-2.

[0071] In some embodiments, the bottom electrode layer 442a-4 and the top electrode layer 442a-8 are conductive material structures. Exemplary conductive materials may include metals, alloys, metal oxides, graphene, etc., or any combination thereof. In some embodiments, metals and alloys may include nickel, iron, lead, platinum, titanium, copper, molybdenum, zinc, or any combination thereof. In some embodiments, alloys may include copper-zinc alloys, copper-tin alloys, copper-nickel-silicon alloys, copper-chromium alloys, copper-silver alloys, etc., or any combination thereof. In some embodiments, metal oxides may include RuO2, MnO2, PbO2, NiO, etc., or any combination thereof.

[0072] The bottom electrode layer 442a-4 may include at least one bottom piezoelectric electrode sheet. The top electrode layer 442a-8 may include at least one top piezoelectric electrode sheet. Each of the at least one bottom piezoelectric electrode sheet is aligned with at least one of the at least one top piezoelectric electrode sheets. In some embodiments, each position of the bottom piezoelectric electrode sheet corresponds to one top piezoelectric electrode sheet. In some embodiments, each position of the bottom piezoelectric electrode sheet corresponds to multiple top piezoelectric electrode sheets, such as 2, 3, 4, etc. The multiple top piezoelectric electrode sheets form a series output unit with the bottom piezoelectric electrode sheet as a common terminal to increase the output voltage and improve sensitivity. The multiple top piezoelectric electrode sheets may also form a parallel output unit with the bottom piezoelectric electrode sheet to increase the output charge and improve sensitivity. The piezoelectric sensing component 442 may include only a series output unit, only a parallel output unit, or both a series output unit and a parallel output unit.

[0073] In some embodiments, the thickness of the bottom electrode layer 442a-4 may be 50-200 nm. In some embodiments, the thickness of the bottom electrode layer 442a-4 may be 100-150 nm. In some embodiments, the thickness of the bottom electrode layer 442a-4 may be 100-200 nm. In some embodiments, the thickness of the bottom electrode layer 442a-4 may be 80-150 nm. In some embodiments, the thickness of the bottom electrode layer 442a-4 may be 150-200 nm. In some embodiments, the thickness of the bottom electrode layer 442a-4 may be 120-150 nm. In some embodiments, the thickness of the bottom electrode layer 442a-4 may be 120-200 nm. In some embodiments, the thickness of the bottom electrode layer 442a-8 may be 50-200 nm. In some embodiments, the thickness of the top electrode layer 442a-8 may be 100-150 nm. In some embodiments, the thickness of the top electrode layer 442a-8 may be 100-200 nm. In some embodiments, the thickness of the top electrode layer 442a-8 can be 80-150 nm. In some embodiments, the thickness of the top electrode layer 442a-8 can be 150-200 nm. In some embodiments, the thickness of the top electrode layer 442a-8 can be 120-150 nm. In some embodiments, the thickness of the top electrode layer 442a-8 can be 120-200 nm. In some embodiments, the thickness of the top electrode layer 442a-8 can be 150-200 nm.

[0074] In some embodiments, the piezoelectric single crystal structure 442a may further include a connection terminal layer 442a-9, connected to the bottom electrode layer 442a-4 or the top electrode layer 442a-8, to output the electrical signal to an external processing circuit. The connection terminal layer 442a-9 may be made of the same material as the bottom electrode layer 442a-4 and the top electrode layer 442a-8, or it may be made of a different material. In some embodiments, the thickness of the connection terminal layer 442a-9 may be 100-200 nm. In some embodiments, the thickness of the connection terminal layer 442a-9 may be 150-200 nm. In some embodiments, the thickness of the connection terminal layer 442a-9 may be 100-150 nm. In some embodiments, the thickness of the connection terminal layer 442a-9 may be 120-200 nm. In some embodiments, the thickness of the connection terminal layer 442a-9 may be 160-200 nm.

[0075] In some embodiments, the piezoelectric sensing component 442 may be a stacked structure composed of piezoelectric single crystal structures. Figure 7 A schematic diagram of a piezoelectric bicrystalline structure 442b of a piezoelectric sensing element 442 provided according to an embodiment of this specification is shown. Figure 7As shown, the piezoelectric bicrystalline structure 442b, from bottom to top along the thickness direction of the piezoelectric sensing component 442, may sequentially include an electrode layer 442b-2, a piezoelectric layer 442b-4, another electrode layer 442b-2, a piezoelectric layer 442b-4, and another electrode layer 442b-2. In some embodiments, the piezoelectric bicrystalline structure 442b may further include a connection terminal layer 442b-9. The electrode layer 442b-2 has a material thickness substantially the same as the bottom electrode layer 442a-4 or the top electrode layer 442a-8 described above, and will not be described further here. The piezoelectric layer 442b-4 has a material thickness substantially the same as the piezoelectric layer 442a-6 described above, and will not be described further here. The connection terminal layer 442b-9 has a material thickness substantially the same as the connection terminal layer 442a-9 described above, and will not be described further here.

[0076] The connecting beam 444 can connect the piezoelectric sensing components 442. For example, the connecting beam 444 can be located between and connect two piezoelectric sensing components 442. The material of the connecting beam 444 can be Si, SiO2, SiNx, etc.

[0077] like Figures 1 to 5 As shown, to improve the sensitivity of the vibration sensor 001, each vibration beam 400 may further include a counterweight 460. The counterweight 460 may be connected to the moving end 440. The counterweight 460 may be directly connected to the moving end 440 or indirectly connected to it. Specifically, the counterweight 460 may be connected to the connecting beam 444. In some embodiments, the counterweight 460 may be located at the center of the moving end 440, so that the counterweight 460 may be located at the center of the cavity 220 in the first direction 221. When the moving end 440 deforms in response to external vibration excitation, the counterweight 460 may generate displacement based on the deformation. In some embodiments, the counterweight 460 may protrude to one side relative to the moving end 420, suspended in the cavity 220. For example, the counterweight 460 may protrude upwards relative to the moving end 420, suspended in the cavity 220. The counterweight 460 can also protrude downward relative to the moving end 420 and be suspended in the cavity 220.

[0078] The counterweight 460 makes the moving end 420 more easily deformable under external force, thereby increasing the electrical signal output by the piezoelectric sensing component 442. In some embodiments, the electrical signal output by the piezoelectric sensing component 442 can be improved by changing the size, shape, and position of the counterweight 460. The arrangement of the counterweight 460 can change the natural frequency and vibration amplitude of the vibrating beam 400.

[0079] In some embodiments, the material of the counterweight 460 may be Si, SiO2, SiNx, etc. The planar shape of the counterweight 460 may be circular, triangular, quadrilateral, polygonal, etc. Taking a quadrilateral planar shape as an example, in some embodiments, the length of the counterweight 460 may be 50µm-500µm. In some embodiments, the length of the counterweight 460 may be 80µm-300µm. In some embodiments, the width of the counterweight 460 may be 50µm-500µm. In some embodiments, the width of the counterweight 460 may be 80µm-200µm. In some embodiments, the width of the counterweight 460 may be greater than, equal to, or less than the width of the vibrating beam 400. In some embodiments, the width of the counterweight 460 may be equal to the width of the vibrating beam 400.

[0080] Because the counterweight 460 is rigidly connected to the moving end 420, the deformation of the moving end 420 at the location of the counterweight 460 is small, resulting in a smaller effective electrical signal voltage. However, the deformation and stress of the moving end 420 near the counterweight 460 are larger, leading to a larger effective electrical signal voltage. Therefore, in some embodiments, the vibration sensor 001 may additionally include a piezoelectric sensing component 442 near the counterweight 460. The additional piezoelectric sensing component 442 can be disposed in the circumferential region near and surrounding the counterweight 460.

[0081] In some embodiments, when the vibration excitation is a mechanical vibration excitation (e.g., vibration sensor 001 is used in a bone conduction microphone), each vibration beam 400 may include a counterweight 460. In some embodiments, when the vibration excitation is an air vibration excitation (e.g., vibration sensor 001 is used in an air conduction microphone), each vibration beam 400 may not include a counterweight 460.

[0082] As previously mentioned, the dimensions of the cavity 220 in the first direction 221 can vary along the second direction 222. That is, the dimensions of the cavity 220 in the first direction 221 change with its position in the second direction 222. In other words, different positions of the cavity 220 in the second direction 222 correspond to different dimensions in the first direction 221. Multiple vibrating beams 400 can be arranged sequentially on the base 200 along the second direction 222. The moving end 440 of each vibrating beam 400 is suspended above the cavity 220. That is, the multiple vibrating beams 400 are located at different positions of the cavity 220 in the second direction 222. Therefore, the dimension (axial dimension of the vibrating beam 400) of the portion of the moving end 440 of each vibrating beam 400 suspended above the cavity 220 in the first direction 221 is different. Therefore, each vibrating beam 400 has a different natural frequency. Multiple vibrating beams 400 correspond to multiple vibration frequencies. Each vibrating beam 400, in response to external vibration excitation, generates a vibration signal within a sub-target frequency window, including its corresponding natural frequency. Different vibrating beams 400 generate vibration signals corresponding to different sub-target frequency windows. The multiple sub-target frequency windows corresponding to the multiple vibrating beams 400 cover different frequency ranges. The multiple sub-target frequency windows constitute a target frequency window. In some embodiments, the target frequency window can be a continuous frequency window. The multiple sub-target frequency windows collectively constitute the continuous target frequency window. In some embodiments, the target frequency window can be any frequency range. The target frequency window can be set based on the usage scenario of the vibration sensor 001. For example, the target frequency window may be different when the vibration sensor 001 is used as a microphone and when it is used as an accelerometer. In some embodiments, the multiple natural frequencies corresponding to the multiple vibrating beams 400 can be uniformly distributed within the target frequency window. In some embodiments, the multiple natural frequencies corresponding to the multiple vibrating beams 400 can be non-uniformly distributed within the target frequency window.

[0083] As mentioned above, the sub-target frequency window may be a frequency window that includes the natural frequency. In some embodiments, the sub-target frequency window may be a frequency window symmetrically arranged with respect to the natural frequency. In some embodiments, the sub-target frequency window may be a frequency window asymmetrically arranged with respect to the natural frequency. In some embodiments, the length of the sub-target frequency window should be within a preset length range. In some embodiments, the coverage range of the sub-target frequency window can be determined based on the amplitude of the vibration signal corresponding to the sub-target frequency window. For example, the amplitude of the vibration signal within the sub-target frequency window should not be less than a preset proportion of the resonant peak value corresponding to the natural frequency. The preset proportion can be any preset proportion, such as 20%, 30%, 50%, etc. In some embodiments, the coverage range of the sub-target frequency window can be determined based on the sensitivity of the vibration signal corresponding to the sub-target frequency window. For example, the sensitivity of the vibration signal within the sub-target frequency window should not be less than a preset threshold.

[0084] In some embodiments, the range of the target frequency window corresponding to the vibration sensor 001 can be determined according to the usage scenario and requirements of the vibration sensor 001, thereby determining the number of multiple vibration beams 400, and the natural frequency and sub-target frequency window corresponding to each vibration beam 400. In some embodiments, when the vibration sensor 001 is used as a microphone (e.g., a bone conduction microphone), the target frequency window can be 100Hz-5000Hz. In some embodiments, the target frequency window of the vibration sensor 001 can be 20Hz-5000Hz. In some embodiments, the number of vibration beams 400 can be two or more. For example, in some embodiments, the number of vibration beams 400 can be 3-50. In some embodiments, the number of vibration beams 400 can be 10-20. In some embodiments, the number of vibration beams 400 can be determined based on the number of resonance peaks required by the vibration sensor 001, according to the usage scenario and requirements of the vibration sensor 001. When only the first-order resonance peak of the vibration beam 400 is used, the number of vibration beams 400 is equal to the number of resonance peaks. When utilizing the higher-order resonance peaks of the vibrating beam 400, the number of vibrating beams 400 is less than the number of resonance peaks. However, the signal intensity of higher-order resonance peaks is usually much smaller than that of first-order resonance peaks. Therefore, the first-order resonance peaks of the vibrating beam 400 are typically used in the vibration sensor 001.

[0085] The natural frequency of the vibrating beam 400 is determined by the characteristics of the vibrating beam 400 itself. The natural frequency of the vibrating beam 400 is related not only to the material properties of the vibrating beam 400, but also to the dimensions of the moving end 440 of the vibrating beam 400 suspended above the cavity 200. As mentioned earlier, the dimensions of the cavity 220 in the first direction 221 are different depending on its position in the second direction 222. Therefore, we can design each vibrating beam 400 according to the dimensions of the cavity 220 in the first direction 221, the position of each vibrating beam 400 in the cavity 220, and the dimensions of each vibrating beam 400, so that the natural frequency of each vibrating beam 400 meets a preset value. Specifically, we can change the dimensions of the cavity 220 in the first direction 221, the position of each vibrating beam 400 in the cavity 220, and the dimensions of each vibrating beam 400, so that the moving end 440 of each vibrating beam 400 suspended above the cavity 220 meets a preset rule, thereby ensuring that the natural frequency of each vibrating beam 400 meets the preset value. The preset value can be the predetermined natural frequency of each vibrating beam 400.

[0086] In some embodiments, the overall dimensions of the multiple vibration beams 400 can be the same. For example, the axial length, width, and thickness of the vibration beams 400 can be identical. By changing the position of the vibration beams 400 on the cavity 220 and the dimensions of the cavity 220 in the first direction 221, the dimensions of the moving ends 440 of the multiple vibration beams 400 suspended on the cavity 220 can be different, thereby giving the multiple vibration beams 400 different natural frequencies that meet preset values. In this case, there is no need to customize the dimensions of each vibration beam 400; simply changing the dimensions of the cavity 220 and the position of the vibration beams 400 on the cavity 220 is sufficient to design the natural frequencies of the multiple vibration beams 400 to meet the preset values. This method can reduce processing difficulty and cost while improving the accuracy of the vibration sensor 001.

[0087] In some embodiments, the overall dimensions of the plurality of vibrating beams 400 may be different. For example, the dimensions of the vibrating beams 400 in at least one of the axial length, width, and thickness directions may be different. By changing the position of the vibrating beams 400 on the cavity 220, the dimensions of the cavity 220 in the first direction 221, and the dimensions of the plurality of vibrating beams 400, the dimensions of the moving ends 440 of the plurality of vibrating beams 400 suspended on the cavity 220 are different, thereby giving the plurality of vibrating beams 400 different natural frequencies and making the natural frequencies meet a preset value.

[0088] For ease of description, we will use the example of multiple vibrating beams 400 having the same overall dimensions.

[0089] For example, taking a target frequency window of 20Hz-5000Hz, with 10 vibrating beams 400, and the natural frequencies of the 10 vibrating beams 400 being evenly distributed within the target frequency window, a certain bandwidth needs to be spaced between the natural frequencies of each vibrating beam 400 for easy differentiation. The bandwidth between each natural frequency is 50Hz-400Hz. In some embodiments, the bandwidth between each natural frequency is 100Hz-200Hz. In some embodiments, the gap width between each vibrating beam 400 can be 1µm-200µm. In some embodiments, the gap width between each vibrating beam 400 is 10µm-100µm. The gap widths between different vibrating beams 400 can be equal or unequal.

[0090] In some embodiments, the length of the moving end 440 of each vibrating beam 400 suspended above the cavity 220 in the first direction 221 can vary linearly or non-linearly. In some embodiments, the vibrating beams 400 on the cavity 220 can be arranged sequentially according to the length of the moving end 440, or arranged according to other rules. The planar shape of each vibrating beam 400 can be rectangular, trapezoidal, curved, etc. In some embodiments, the cross-sectional width of each vibrating beam 400 can be 50µm-300µm. In some embodiments, the cross-sectional width of each vibrating beam 400 can be 80µm-200µm. In some embodiments, the axial length of each vibrating beam 400 can be 100µm-1300µm. In some embodiments, the axial length of each vibrating beam 400 can be 200µm-1200µm.

[0091] As mentioned above, in some embodiments, the vibrating beam 400 may not include the counterweight 460. For example, in an air conduction microphone, since the energy of air vibration excitation is relatively small, the gap width between adjacent vibrating beams 400 can be reduced to increase the output of the vibration signal.

[0092] In some embodiments, the vibrating beam 400 may further include a counterweight 460. In this case, each vibrating beam 400 can be designed according to the dimensions of the cavity 220 in the first direction 221, the position of each vibrating beam 400 on the cavity 220, the dimensions of each vibrating beam 400, and the dimensions of the counterweight 460, so that the natural frequency of each vibrating beam 400 meets a preset value. Specifically, we can change the dimensions of the cavity 220 in the first direction 221, the position of each vibrating beam 400 on the cavity 220, the dimensions of each vibrating beam 400, and the dimensions of the counterweight 460, so that the moving end 440 of each vibrating beam 400 suspended on the cavity 220 meets a preset rule, thereby ensuring that the natural frequency of each vibrating beam 400 meets the preset value.

[0093] Figure 8A normalized displacement resonance curve is shown according to an embodiment of this specification. Figure 8 The curve shown can be a normalized displacement resonance curve corresponding to one of multiple vibrating beams 400. For example... Figure 8 As shown, the horizontal axis represents the ratio of the external vibration excitation ω to the natural frequency ω0 of the vibrating beam 400, and the vertical axis represents the normalized displacement A. The normalized displacement A can be the ratio of the displacement amplitude of the vibrating beam 400 to the static displacement amplitude. The static displacement amplitude can be the displacement amplitude when the external vibration excitation is constant (i.e., ω = 0). Where M is the mass of the vibrating beam 400, i.e., the mass of the moving end 440 and the counterweight 460. K is the elastic modulus of the vibrating beam 400. Figure 8 As shown, when the natural frequency ω0 of the vibrating beam 400 is equal to the external vibration excitation ω, the normalized displacement A reaches its maximum, that is, the displacement at the resonant frequency reaches its peak (i.e., the resonant peak). Therefore, in order to improve the sensitivity of the vibration sensor 001, for the vibration signal collected by the piezoelectric sensing component 442, we can select a preset frequency range near the natural frequency ω0 of the vibrating beam 400 as the sub-target frequency window corresponding to each vibrating beam 400, and use the vibration signal within the sub-target frequency window as the vibration signal generated by the vibrating beam 400.

[0094] Figure 8 The different curves shown correspond to six different mechanical quality factors Q of the vibrating beam 400. Among them, Where R is the damping of the vibrating beam 400. For example... Figure 8 As shown, when the natural frequency ω0 of the vibrating beam 400 is determined, the larger the mechanical quality factor Q of the vibrating beam 400, the larger its corresponding normalized displacement A. The normalized displacement A corresponds to a larger electrical signal of the vibration signal output by the piezoelectric sensing component 442.

[0095] When multiple vibrating beams 400 are mounted on the base 200, the vibration signals generated by the multiple vibrating beams 400 will couple and superimpose with each other. If the stiffness and mass of the base 200 are much greater than the stiffness and mass of the vibrating beams 400, the coupling effect between different vibrating beams 400 can be ignored. That is, it can be considered that the electrical signals of the vibration signals output by the vibration sensor 001 are linearly superimposed. Figure 9 A schematic diagram of a vibration signal provided according to an embodiment of this specification is shown. Figure 9The vibration signal shown is a linear superposition of multiple vibration signals generated by multiple vibrating beams 400. In some embodiments, to facilitate subsequent signal processing, the deviation of the vibration signals output by different vibrating beams 400 at their corresponding natural frequencies can be within a preset deviation range. This ensures that the vibration signals output by different vibrating beams 400 at their corresponding natural frequencies are within the same or similar order of magnitude, facilitating calculation. The preset deviation range can be a pre-set range that facilitates signal calculation. The preset deviation range can be based on empirical values, obtained through experimental statistics, or obtained through machine learning. The deviation of the vibration signals output by different vibrating beams 400 at their corresponding natural frequencies within the preset deviation range can mean that the deviation of the normalized displacement A of the vibration signals output by different vibrating beams 400 at their corresponding natural frequencies does not exceed the preset deviation range. In some embodiments, the preset deviation range can be any value, such as ±30%, ±20%, ±10%, etc. In some embodiments, we can design the mechanical quality factor Q of each vibrating beam 400 such that the deviation of the mechanical quality factors Q of multiple vibrating beams 400 is within a preset deviation range, thereby ensuring that the deviation of the normalized displacement A of the vibration signal output by different vibrating beams 400 at its corresponding natural frequency is within the preset deviation range. In some embodiments, we can design the size of the counterweight 460 to match the natural frequency of its corresponding vibrating beam 400, ensuring that the deviation of the mechanical quality factor Q of each vibrating beam 400 is within a preset deviation range, thereby ensuring that the deviation of the vibration signal corresponding to each vibrating beam 400 at its corresponding natural frequency is within the preset deviation range. Specifically, given the natural frequency ω0 of the vibrating beam 400, by designing and changing the size of the cavity 220 in the first direction 221, the position of the vibrating beam 400 in the cavity 220, the size of the moving end 440, and the size of the counterweight 460, we can ensure that the deviation of the mechanical quality factor Q of each vibrating beam 400 is within the preset deviation range, thereby ensuring that the deviation of the vibration signal corresponding to each vibrating beam 400 at its corresponding natural frequency is within the preset deviation range.

[0096] In some embodiments, the deviation of the normalized displacement A of the vibration signals output by different vibrating beams 400 at their corresponding natural frequencies may also be outside the preset deviation range. Those skilled in the art should understand that the fact that the normalized displacement A of the vibration signals output by different vibrating beams 400 is outside the preset deviation range at their corresponding natural frequencies does not affect the superposition processing of the vibration signals and is also within the scope of protection of this specification.

[0097] This specification also provides a microphone, which may include a housing and a vibration sensor 001 provided herein. The vibration sensor 001 can be installed in the housing. The housing can be fixedly connected to the base 200. The housing and the base 200 can be an integral structure or a separate structure, and are connected together by a fixed connection method, such as welding, riveting, bolting, bonding, etc. When the housing is subjected to external force vibration (for example, the vibration of a person's face when speaking causes the housing to vibrate), the vibration of the housing causes the base 200 to vibrate. Due to the different properties of the vibration beam 400 and the housing structure (or base 200), the vibration beam 400 and the housing structure (or base 200) cannot maintain completely synchronized movement, thus generating relative motion, which in turn causes the vibration beam 400 to undergo the aforementioned deformation. The piezoelectric sensing component 442 converts the deformation into the vibration signal and outputs it.

[0098] In some embodiments, the microphone may further include a signal synthesis circuit. The signal synthesis circuit is connected to the piezoelectric sensing element 442 of each vibrating beam 400, and during operation, it acquires the vibration signal collected by each piezoelectric sensing element 442 and performs signal synthesis processing to generate a vibration signal within a target frequency window. The signal synthesis processing may involve linearly superimposing multiple vibration signals generated by multiple vibrating beams 400.

[0099] By way of example only, the microphone described in this specification can be applied to a variety of electronic products, such as headphones (e.g., bone conduction headphones or air conduction headphones, wireless headphones, wired headphones), smart glasses, smart wearable devices, smart helmets, smartwatches, and other devices with voice acquisition capabilities.

[0100] In summary, the vibration sensor 001 and microphone provided in this specification have a vibration beam 400 fixed to the base 200 by its two fixed ends 420, while the movable end 440 in the middle is suspended in the cavity 220 and deforms in response to external vibration excitation. By changing the structure and size of the cavity 220 and the size and position of the vibration beam 400, the vibration sensor 001 and microphone allow for different sizes of the suspended portions of the multiple vibration beams 400 above the cavity 220, resulting in different natural frequencies for each beam and generating resonance peaks of different frequencies under vibration excitation. Multiple vibration beams 400 can generate vibration signals within multiple frequency ranges, which together constitute a wideband vibration signal, thus widening the frequency response range of the vibration sensor 004. Furthermore, the vibration signal selected by the vibration sensor 001 and microphone is within a preset range near the resonance peak, resulting in higher sensitivity. Furthermore, the vibration sensor 001 and microphone achieve multi-resonance peaks and wide bandwidth through the design of the dimensions of the base 200 cavity 220. This results in a simple structure, low manufacturing difficulty, low manufacturing cost, and higher precision, leading to more accurate vibration signal acquisition. Simultaneously, based on the vibration signals acquired by the vibration sensor 001 and microphone 002 provided in this specification, subsequent vibration signal processing allows for the use of low-order filters in later algorithmic processing. Figure 9 The vibration signal shown can be used to extract the output displacement signal at different frequencies with steep cutoff edges, thereby extracting the input signal at different frequencies. This avoids the need for later algorithms to use high-order filters to extract the signal, reducing the computational load of the algorithm.

[0101] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0102] In summary, after reading this detailed disclosure, those skilled in the art will understand that the foregoing detailed disclosure is presented by way of example only and is not restrictive. Although not explicitly stated herein, those skilled in the art will understand that this specification requires various reasonable changes, improvements, and modifications to the embodiments. These changes, improvements, and modifications are intended to be made by this specification and are within the spirit and scope of the exemplary embodiments described herein.

[0103] Furthermore, certain terms in this specification have been used to describe embodiments of this specification. For example, "an embodiment," "an embodiment," and / or "some embodiments" mean that a particular feature, structure, or characteristic described in connection with that embodiment may be included in at least one embodiment of this specification. Therefore, it is to be emphasized and understood that two or more references to "an embodiment" or "an embodiment" or "alternative embodiment" in various parts of this specification do not necessarily refer to the same embodiment. Moreover, specific features, structures, or characteristics may be suitably combined in one or more embodiments of this specification.

[0104] It should be understood that in the foregoing description of the embodiments in this specification, various features are combined in a single embodiment, drawing, or description for the purpose of simplifying the description and to aid in understanding a feature. However, this does not mean that the combination of these features is necessary, and those skilled in the art may extract some features as individual embodiments when reading this specification. That is, the embodiments in this specification can also be understood as an integration of multiple sub-embodiments. It is also valid when each sub-embodiment contains fewer than all the features of a single foregoing disclosed embodiment.

[0105] Each patent, patent application, publication of the patent application, and other materials such as articles, books, specifications, publications, documents, articles, etc., cited herein may be incorporated by reference. Except for any examination history documents associated with it, any identical or potentially restrictive examination history documents that may be inconsistent with or conflict with this document, or any other contents used for all purposes, may be relevant to this application now or in the future, and the terminology used therein shall be as used in this application. For example, in the event of any inconsistency or conflict between the description, definition, and / or use of terms associated with any included material and the terminology, description, definition, and / or used in connection with this document, the terminology in this document shall prevail.

[0106] Finally, it should be understood that the embodiments disclosed herein are illustrative of the principles of the embodiments described in this specification. Other modified embodiments are also within the scope of this specification. Therefore, the embodiments disclosed in this specification are merely examples and not limitations. Those skilled in the art can implement the applications described in this specification using alternative configurations based on the embodiments in this specification. Therefore, the embodiments in this specification are not limited to the embodiments precisely described in the applications.

Claims

1. A vibration sensor, characterized in that, include: Rigid base, including cavity; as well as Multiple vibrating beams are arranged sequentially on the base, wherein each vibrating beam comprises: The first fixed end and the second fixed end are located at the two ends of the vibrating beam, respectively, and are connected to the base; and The mobile end, located between the first fixed end and the second fixed end and suspended above the cavity, includes: a first piezoelectric sensing component, a second piezoelectric sensing component, and a connecting beam connected to the first and second piezoelectric sensing components; the first and second piezoelectric sensing components are respectively connected to the first and second fixed ends, and their maximum length is one-quarter of the length of the mobile end, so as to convert the vibration deformation of the mobile end into a vibration signal; Each of the plurality of vibrating beams has a different natural frequency, and the moving end of each vibrating beam responds to external vibration excitation to generate a vibration signal within a sub-target frequency window, including its corresponding natural frequency.

2. The vibration sensor as described in claim 1, characterized in that, The multiple sub-target frequency windows corresponding to the multiple vibration beams cover different frequency ranges, and the multiple sub-target frequency windows constitute the target frequency window.

3. The vibration sensor as described in claim 2, characterized in that, The multiple natural frequencies corresponding to the multiple vibrating beams are evenly distributed within the target frequency window.

4. The vibration sensor as described in claim 1, characterized in that, The dimensions of the cavity change along a second direction in a first direction, the plurality of vibrating beams are arranged on the base along the second direction, and the fixed end is connected to the base along the first direction.

5. The vibration sensor as described in claim 4, characterized in that, The dimensions of the cavity in the first direction, the position of each vibrating beam on the cavity, and the dimensions of each vibrating beam satisfy a preset rule, such that the natural frequency of each vibrating beam satisfies a preset value.

6. The vibration sensor as described in claim 1, characterized in that, Each of the plurality of vibrating beams has a different size suspended above the cavity.

7. The vibration sensor as described in claim 6, characterized in that, The overall dimensions of the multiple vibrating beams are the same.

8. The vibration sensor as described in claim 6, characterized in that, The cavity includes a first side and a second side that are opposite to each other but not parallel, and the plurality of vibrating beams span the first side and the second side.

9. The vibration sensor as described in claim 6, characterized in that, The piezoelectric sensing component includes at least one of a piezoelectric single crystal structure and a piezoelectric dual crystal structure.

10. The vibration sensor as described in claim 1, characterized in that, Each vibrating beam also includes: A counterweight is connected to the mobile end, wherein the mobile end deforms in response to the vibration excitation, and the counterweight generates displacement based on the deformation.

11. The vibration sensor as described in claim 10, characterized in that, The dimensions of the cavity in the first direction, the position of each vibrating beam on the cavity, the dimensions of each vibrating beam, and the dimensions of the counterweight meet preset rules, so that the natural frequency of each vibrating beam meets a preset value.

12. The vibration sensor as described in claim 11, characterized in that, The size of the counterweight is matched with the natural frequency of its corresponding vibrating beam, so that the deviation of the vibration signal of the plurality of vibrating beams at their corresponding natural frequencies is within a preset deviation range.

13. The vibration sensor as described in claim 1, characterized in that, The plurality of vibrating beams are configured to receive air vibration excitation acting on them.

14. A microphone, characterized in that, include: case; The vibration sensor according to any one of claims 1-13 is installed in the housing, and the base is fixedly connected to the housing; as well as A signal synthesis circuit is connected to the plurality of vibrating beams. During operation, it acquires the vibration signals and performs signal synthesis processing on the vibration signals to generate vibration signals within the target frequency window. The plurality of sub-target frequency windows corresponding to the plurality of vibrating beams cover different frequency ranges, and the plurality of sub-target frequency windows constitute the target frequency window.

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