Novel controllable topological acoustic switch

Abstract

The utility model discloses a novel controllable topology acoustic switch mainly includes a plurality of controllable topology phononic crystal device and motor slot array, is divided into three layers in general, from below to top is driving layer, control layer and rotating layer in proper order, driving layer includes direct current supply and drive board, and control layer includes the wire harness of step motor and the control board being connected with it, and rotating layer includes motor slot array, step motor, big gear, pinion, double -layer acrylic plate, rectangular scatterer and its connecting rod, driving layer input corner and send out control signal, and control layer receives the signal from control board and controls the effect of step motor, and rotating layer converts the rotation of step motor into the rotation of rectangular scatterer on acrylic plate. The utility model has realized the regional control of topology phononic crystal, has improved the efficiency of topology phononic crystal control significantly, and has provided complete platform design scheme for realizing the efficient control of topology phononic crystal.

Description

Technical Field

[0001] This invention relates to the field of acoustic metamaterials, and in particular to a novel tunable topological acoustic switch capable of switching between two different acoustic topological interface states. Background Technology

[0002] Acoustic metamaterials, through artificial structural design, have achieved unprecedented material properties and have wide applications in the field of acoustics. Acoustic metamaterials can realize various subwavelength designs to obtain effective acoustic parameters invisible in nature, thus enabling the development of new applications. By realizing complex lattices with different lattice symmetries, topological phononic crystals have become an effective platform for exhibiting interesting topological properties and new applications. Programmable acoustic topological insulators, combined with microcontroller control systems and programmable second-order topological imaging, have elevated the design of topological acoustics to the application level. Utilizing special frequency band characteristics, directional topological antennas and multi-port valves for acoustic energy distribution have also been realized. However, most topological phononic crystals in existing technologies are difficult to control. The few controllable studies that do employ common control methods are limited to manual adjustments in numerical simulations and experiments, making automated control or even arbitrary reconfiguration difficult, resulting in low control efficiency. Existing control methods that change the cylinder radius can only switch between two radii, but cannot achieve arbitrary parameter reconfiguration or continuous change of the phononic crystal's structural parameters, significantly limiting the development of related applications. Summary of the Invention

[0003] Purpose of the utility model: The purpose of this utility model is to provide a novel adjustable topological acoustic switch that can switch between two different acoustic topological interface states.

[0004] Technical Solution: This utility model is a novel adjustable topological acoustic switch, comprising multiple adjustable topological phonon crystal devices and a motor slot array; it is generally divided into three layers, from bottom to top: a driving layer, a control layer, and a rotation layer; the driving layer includes a DC power supply and a driving board, the control layer includes a stepper motor cable and a control board connected to it, and the rotation layer includes a motor slot array, a stepper motor, a large gear, a small gear, a double-layer acrylic plate, a rectangular scatterer, and its connecting rod; the driving layer inputs the rotation angle and sends control signals, the control layer receives signals from the control board and controls the action of the stepper motor, and the rotation layer converts the rotation of the stepper motor into the rotation of the rectangular scatterer on the acrylic plate.

[0005] Furthermore, the tunable topological phonon crystal device includes a rectangular scatterer and its connecting rod, a pinion, a double-layer acrylic plate, a cylindrical scatterer, a stepper motor, a large gear and its connecting body, and a microcontroller control system.

[0006] Furthermore, the rectangular scatterer and its connecting rod are made of epoxy resin material by 3D printing, including 6 rectangular scatterers, each of which is connected to a cylindrical rod at the bottom. Two protrusions are provided at the junction of the abrupt change in thickness at the bottom and middle of the cylindrical rod.

[0007] Furthermore, the double-layer acrylic plate comprises upper and lower layers. The lower acrylic plate has six countersunk holes, the lower radius of which is smaller than the upper radius. The upper acrylic plate has six large holes and six small holes. The center position and size of the six large holes are the same as those of the cylindrical scatterer. The center position of the six small holes is the same as that of the six rectangular scatterers. The diameter of the six small holes is the same as the diameter of the upper and middle parts of the rectangular scatterer connector.

[0008] Furthermore, the microcontroller control system includes a driver board, a control board, and a DC power supply, with the microcontroller located in the rectangular area slightly to the left of the center of the driver board.

[0009] Furthermore, a rectangular hole is provided behind each groove in the motor slot array, and the spacing between each motor slot is equal to the lattice constant of the unit cell.

[0010] Furthermore, the motor slot array is made of hollow epoxy resin material through 3D printing.

[0011] Beneficial effects: Compared with the prior art, this utility model has the following advantages: (1) By flexibly adjusting the rotation angle of the rectangular scatterer in the unit cell of the phononic crystal in a certain region, the switching between two different acoustic topological interface states can be realized within a specific frequency range, thereby changing the transmission direction of the sound wave. (2) It realizes the regional control of topological phononic crystals; significantly improves the efficiency of topological phononic crystal control; and provides a complete platform design scheme for realizing efficient control of topological phononic crystals. Attached Figure Description

[0012] Figure 1 A three-dimensional schematic diagram of a novel tunable topological phononic crystal device (unit cell); Figure 2 Top view of the transmission mechanism of a novel tunable topological phononic crystal device (unit cell); Figure 3 Side view of the transmission mechanism of a novel tunable topological phononic crystal device (unit cell); Figure 4 A schematic diagram showing the connection between the rectangular scatterer, its connecting rod, and the pinion; Figure 5 This is a schematic diagram of a double-layer acrylic sheet. Figure 6 The PCB schematics are for the driver board and the control board. Figure 7 This is a schematic diagram of a novel tunable topological phononic crystal device (array). Figure 8 A schematic diagram of the physical mechanism of a novel tunable topological acoustic switch; Figure 9 The simulation results show the sound pressure field distribution of a novel tunable topological acoustic switch. Detailed Implementation

[0013] The technical solution of this utility model will be further described below with reference to the accompanying drawings.

[0014] This invention relates to a novel adjustable topological acoustic switch, comprising multiple adjustable topological phonon crystal devices and a motor slot array 10; such as Figure 1 , 2 As shown in Figure 3, the adjustable topological phonon crystal device includes a rectangular scatterer and its connecting rod 1, a pinion 2, a double-layer acrylic plate 3, a cylindrical scatterer 4, a stepper motor 5, a large gear 6 and its connecting body, and a microcontroller control system. The rectangular scatterer and its connecting rod are made of epoxy resin material using 3D printing technology. One unit cell contains 6 rectangular scatterers, and each rectangular scatterer is connected to a cylindrical rod at its lower part. There are two protrusions at the junction of the lower and middle parts of the cylindrical rod where the thickness changes abruptly. like Figure 4 As shown, the pinion is made of epoxy resin using 3D printing technology. There is a circular hole in the center of the pinion, the diameter of which is the same as the diameter of the upper and middle parts of the rectangular phonon crystal connecting rod. Inside the circular hole, there are two grooves of the same size as the protrusions on the rectangular scatterer and its connecting rod. The protrusions on the rod can be inserted into the grooves on the pinion, so that the rod connected to the rectangular scatterer can be fixed on the pinion without relative rotation. The appropriate degree of friction between the grooves on the pinion and the protrusions on the rod prevents the pinion from falling off, while the rod can be pulled out when the external force is large. like Figure 5As shown, the double-layer acrylic sheet consists of an upper and a lower acrylic sheet. The lower acrylic sheet has six countersunk holes based on the center positions of the six rectangular scatterers. Since the lower radius of the countersunk holes is smaller than the upper radius, six miniature bearings are placed in the countersunk holes to prevent them from falling. The upper acrylic sheet contains six large holes and six small holes. The center position and size of the six large holes are the same as those of the cylindrical scatterers. The center position of the six small holes is the same as that of the center positions of the six rectangular scatterers. The diameter of the six small holes is the same as the diameter of the upper and middle parts of the rectangular scatterer connector. Before the rectangular scatterers and their connectors are combined with the pinion, they need to be inserted into and penetrate the double-layer acrylic sheet. After placing the upper acrylic sheet on top of the lower acrylic sheet containing the six miniature bearings and aligning the small holes on the upper sheet with the small holes on the bearings, the rectangular scatterers and their connecting rods can be inserted into the small holes and penetrate the double-layer acrylic sheet. Then, the pinion is connected to the rectangular scatterers and their connecting rods. The cylindrical scatterer is made of epoxy resin material using 3D printing technology. After the upper and lower acrylic plates are stacked together, the area below the large hole of the upper acrylic plate is the area without holes in the lower acrylic plate, forming a cylindrical groove into which the cylindrical scatterer can be embedded. The plane where the highest point of the cylindrical scatterer and the rectangular scatterer are located is at the same height. The stepper motor, model 28BYJ48, is connected to the large gear on its upper surface by tightly wrapping a hollow cylinder with rounded rectangular holes of the same size around the rotor. When the rotor of the stepper motor rotates, it will drive the large gear to rotate synchronously. After fixing the corners of the six rectangular scattering bodies with a mold, the large gear is installed between the six small gears. Then the mold is removed, and the six cylindrical scattering bodies are placed into the grooves of the upper acrylic plate. The transmission device is then completed. like Figure 6As shown, the microcontroller control system consists of two different types of circuit boards—a driver board and a control board. The rectangular area slightly to the left of the center of the driver board is the microcontroller (MCU), model STC89C52, which is used to process input signals and generate control signals for the stepper motor. The yellow dashed box in the lower left corner of the driver board contains four buttons, each with a different function, represented by the letters A, B, C, and D. Buttons A and B control the stepper motor rotation angle displayed on the LED screen above. Each press of button A increases the displayed angle by 1°, and each press of button B decreases the displayed angle by 1°. Once the required rotation angle of the stepper motor is determined, pressing button C will rotate the stepper motor clockwise from the current angle displayed on the LED screen. Button D keeps the stepper motor rotating, and pressing it again will stop the rotation. The black and red wires on the right side of input port A are used to connect to the power supply. The external power supply is a DC power supply with an input voltage of approximately 10V. There are 10 black ports on the right side, each of which can be connected to a control board. Input port B in the lower right corner of the control board is an interface, the same as the interface in port area A of the driver board. The two are connected via a double-ended ribbon cable.

[0015] like Figure 7 As shown, the novel adjustable topological acoustic switch is generally divided into three layers, from bottom to top: a driving layer, a control layer, and a rotation layer. The driving layer includes a DC power supply 9 and a driving board 7. The control layer includes a stepper motor cable and a control board 8 connected to it. The rotation layer includes a motor slot array 10, a stepper motor 5, a large gear 6, a small gear 2, a double-layer acrylic plate 3, and a rectangular scattering body connecting rod 1. The driving layer inputs the rotation angle and sends out control signals. The control layer receives signals from the control board and controls the action of the stepper motor. The rotation layer converts the rotation of the stepper motor into the rotation of the rectangular scattering body on the acrylic plate.

[0016] To fix the position of the stepper motor, several grooves made of hollow epoxy resin material can be made using 3D printing technology according to the contour of the bottom of the stepper motor. The stepper motor can be placed in the grooves. A rectangular hole can be designed behind each groove to allow the motor interface and cable to extend into the groove. The spacing between each motor groove is equal to the lattice constant of the unit cell. The device uses a height-adjustable lifting platform as a support and takes advantage of the sturdy yet permeable metal mesh structure. This allows it to be used to place the support while also allowing the dense wires on the motor to extend underneath without obstruction, thus greatly expanding the usable space of the device. In addition, the bottom of the shelf is equipped with wheels, which can move the entire device, making it very flexible and convenient. A novel tunable topological acoustic switch involves switching between two acoustic topological interface states with different propagation paths. An acoustic topological interface state refers to the state in which sound waves propagate locally at the interface between two artificial materials with different topological properties (phononic crystal arrays with different rotation angles and inverted band structures) and along the interface. Based on the novel tunable topological phononic crystal device (array), by flexibly adjusting the rotation angle of the rectangular scatterers in a portion of the phononic crystal unit cell, switching between two different acoustic topological interface states can be achieved within a specific frequency range, thereby changing the direction of sound wave propagation. For example, as... Figure 8 As shown in Figure 8(a), the acoustic topology interface state transmission originally reached the right port, which was initially in an "open" state. In Figure 8(b), after adjusting the rotation angle of the phonon crystal unit cell in the upper right region, the sound wave no longer reached that port, and its state changed to "closed". In this way, a novel tunable topological acoustic switch can be realized.

[0017] In this embodiment, the pressure acoustics module in COMSOL Multiphysics simulation software is used to simulate the sound field, and the sound pressure field distribution is obtained through numerical calculation. The material parameters of the epoxy resin are: sound velocity 2720 m / s, density 1180 kg / m³. 3 The material parameters of air are: speed of sound 343 m / s, density 1.21 kg / m³. 3 A 20×24 composite honeycomb phonon crystal array can be constructed. The structural parameters of each phonon crystal unit cell are: lattice constant 52.8 mm, length of rectangular scatterer 10.9 mm, width of rectangular scatterer 1.6 mm, diameter of cylindrical scatterer 13.3 mm, and distance from the rectangular scatterer to the unit cell center 12.5 mm. The geometry of each rectangular scatterer pointing towards the unit cell center along its length is defined as the rotation angle. θ = 0°, and based on this, the rectangular scatterer rotates clockwise by an angle θ. The rotation angle of the rectangular scatterer in the same unit cell is always the same. θ The boundary conditions around the phonon crystal array are set to plane wave radiation.

[0018] like Figure 9As shown, 9(a) displays the sound pressure field distribution in the "on" state at a frequency of 5670 Hz; 9(b) displays the sound pressure field distribution in the "off" state at a frequency of 5670 Hz. The upper phonon crystal has a rotation angle of 0°, and the lower phonon crystal has a rotation angle of 45°. A point sound source is incident from the left interface. It can be seen that the sound energy is stably transmitted to the right along the interface with these two different rotation angles, and the right port can receive almost all the energy from the left. 9(b) shows that when the rotation angle in the upper right region changes to 45°, due to the change in the interface, the sound wave incident from the left turns to the upper right at the interface corner instead of continuing to transmit to the right, and the right port receives almost no sound energy. By performing line integration on the sound energy at the upper and right ports, the transmittance of the sound energy in both cases can be calculated. When the state is "on", the acoustic energy transmittance of the right port is 1 (0 dB); when the state is "off", the acoustic energy transmittance of the right port is 0.00001 (-50 dB), exhibiting excellent switching characteristics.

Claims

1. A novel adjustable topological acoustic switch, characterized in that: It includes multiple adjustable topological phonon crystal devices and a motor slot array (10); it is generally divided into three layers, from bottom to top: a driving layer, a control layer and a rotation layer; the driving layer includes a DC power supply (9) and a driving board (7), the control layer includes the wiring of the stepper motor and the control board (8) connected to it, and the rotation layer includes a motor slot array (10), a stepper motor (5), a large gear (6), a small gear (2), a double-layer acrylic plate (3), a rectangular scatterer and its connecting rod (1) and a cylindrical scatterer (4); the driving layer inputs the rotation angle and sends out the control signal, the control layer receives the signal from the control board and controls the action of the stepper motor, and the rotation layer converts the rotation of the stepper motor into the rotation of the rectangular scatterer on the acrylic plate.

2. The novel adjustable topological acoustic switch according to claim 1, characterized in that: The adjustable topological phonon crystal device includes multiple periodically arranged rectangular scatterers and their connecting rods (1), a small gear (2), a double-layer acrylic plate (3), a cylindrical scatterer (4), a stepper motor (5), a large gear (6) and its connecting body, and a single-chip microcomputer control system.

3. The novel adjustable topological acoustic switch according to claim 1, characterized in that: The rectangular scatterer and its connecting rod (1) are made of epoxy resin material by 3D printing. One unit cell includes 6 rectangular scatterers. Each rectangular scatterer is connected to a cylindrical rod below it. Two protrusions are provided at the junction of the abrupt change in thickness at the bottom and middle of the cylindrical rod.

4. The novel adjustable topological acoustic switch according to claim 1, characterized in that: The double-layer acrylic plate (3) includes upper and lower layers. The lower acrylic plate has 6 countersunk holes with a lower radius smaller than the upper radius. The upper acrylic plate has 6 large holes and 6 small holes. The center position and size of the 6 large holes are the same as those of the cylindrical scatterer. The center position of the 6 small holes is the same as that of the 6 rectangular scatterers. The diameter of the 6 small holes is the same as the diameter of the upper and middle parts of the rectangular scatterer connector.

5. The novel adjustable topological acoustic switch according to claim 2, characterized in that: The microcontroller control system includes a driver board (7), a control board (8), and a DC power supply (9). The microcontroller is located in the rectangular area slightly to the left of the center of the driver board.

6. The novel adjustable topological acoustic switch according to claim 1, characterized in that: A rectangular hole is provided behind each groove in the motor slot array (10), and the spacing between each motor slot is equal to the lattice constant of the unit cell.

7. The novel adjustable topological acoustic switch according to claim 1, characterized in that: The motor slot array (10) is made of hollow epoxy resin material by 3D printing.

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