Magnetic-thermal response type photonic crystal plate device and elastic trough state transmission characteristic regulation and control method thereof

Abstract

The invention discloses a magnetic-thermal response type phononic crystal plate device and an elastic trough state transmission characteristic regulation and control method thereof, and relates to the technical field of novel artificial metamaterials. The magnetic-thermal response type phononic crystal plate device comprises a magnetic-thermal-elastic phononic crystal plate and a plurality of magnets and thermoelectric pieces; the phononic crystal plate is formed by arranging a plurality of unit cell structures, and each unit cell is composed of a magnetostrictive column and an aluminum plate; the external magnetic field is regulated and controlled by adjusting the distance between the magnet blocks; the temperature of different magnetostriction columns is controlled by controlling the thermoelectric pieces, so that the adjustment of a temperature field is realized; a broadband elastic trough Hall interface state is induced to be generated, and dynamic adjustability of magnetic-thermal dual excitation to a trough topology transmission path is achieved on the premise that the structure is not changed. The technical problem that the frequency of the elastic trough Hall interface state and the topological transmission path are difficult to dynamically regulate and control on the premise that the structure of a traditional topological photonic crystal is not changed is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of artificial metamaterials, and in particular relates to a magnetic-thermal responsive phononic crystal plate device and a method for regulating elastic wave valley state transmission characteristics thereof. Background Art

[0002] Phononic crystals are acoustic metamaterials with periodic arrangement of geometric structures or physical parameters. They have properties such as pass / gap bands, defect states, and directional propagation. They can provide an effective research method for regulating elastic waves / acoustic waves and have important application value in vibration reduction and isolation, noise suppression, energy capture and other fields.

[0003] Directional transmission of elastic waves and energy flow control are the core contents of phononic crystal research. When elastic waves propagate to boundaries or defects, there is often a strong scattering loss effect, which greatly affects the transmission effect and has certain limitations. Topological insulators based on phononic crystals can achieve low-loss or even lossless directional transmission of elastic waves, and have characteristics such as "backscattering suppression" and "defect immunity". Such topologically protected phononic crystals are called topological phononic crystals. As an acoustic metamaterial with special topological properties, topological phononic crystals have periodic internal geometric structures or physical parameters, which modulate the propagation of elastic waves in them, forming specific passbands and forbidden bands (band gaps). The band gap frequency is an important feature of topological phononic crystals. It determines which frequency ranges of elastic waves can propagate without loss in phononic crystals, and which frequency ranges of elastic waves will be suppressed or prohibited from propagating. The elastic valley Hall interface state is a special interface state in topological phononic crystals. It has unique frequency, position and propagation path. These characteristics make it have potential application value in acoustic waveguides, filters and other fields.

[0004] However, existing topological phononic crystals still face some limitations. For example, the operating frequency is fixed. Once the topological phononic crystals are manufactured, their band gap frequency is fixed, which means that topological phononic crystals can only control elastic waves within a specific frequency range, and cannot adapt to changes in external conditions or multi-frequency application requirements. At the same time, when phononic crystal devices serve in complex dielectric environments, their working performance is affected by external loads such as magnetic fields, stress, and temperature, which will cause losses and interference due to contact, greatly reducing the stability and reliability of the device. At present, most phononic crystals do not have the characteristics of non-contact active regulation of elastic wave topological transmission.

[0005] Chinese patent CN117350071A discloses a design method for ultra-wideband topological valley state transmission phononic crystal plates. However, once the phononic crystal plate structure in the patent is prepared, the band structure of the topological phononic crystal plate and the frequency and position of the valley Hall interface state will not change, so it can only control elastic waves in a specific frequency range and a specific propagation path. It can be seen that dynamically regulating the topological transmission characteristics of elastic waves without changing the structure, or compensating for changes caused by external factors to improve device stability, will become a research hotspot for tunable topological phononic crystals. Summary of the invention

[0006] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a magnetic-thermal responsive phononic crystal plate device and a method for controlling the transmission characteristics of its elastic valley state, which solves the technical problem that traditional topological phononic crystal devices are difficult to dynamically control the frequency and topological transmission path of the elastic valley Hall interface state without changing the structure.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention provides a magnetic-thermal responsive phononic crystal plate device, characterized in that it comprises an optical platform and a phononic crystal plate, wherein the phononic crystal plate comprises a plurality of periodically distributed unit cells;

[0009] A group of magnetic field adjustment controls are symmetrically arranged above and below the phononic crystal plate, the magnetic field adjustment controls are connected to the optical platform through a supporting component, the magnetic field adjustment controls include a connecting plate and a plurality of groups of magnetic field adjustment units, each group of magnetic field adjustment units is arranged on the connecting plate, and each group of magnetic field adjustment units correspondingly adjusts the magnetic field strength of a unit cell; a temperature field adjustment control is arranged between the phononic crystal plate and the magnetic field adjustment control above it, the temperature field adjustment control is connected to the optical platform through a fixing part, the temperature field adjustment control includes a plurality of thermoelectric sheets, and each thermoelectric sheet correspondingly adjusts the temperature of a group of magnetic field adjustment units;

[0010] One side of the unit cell is connected to an exciter, which is connected to a power supply; the exciter, a magnetic field adjustment control unit, a temperature field adjustment control unit, a phononic crystal plate and a power supply form a closed circuit.

[0011] Preferably, the unit cell is composed of an aluminum plate and six magnetostrictive columns to form a hexagonal honeycomb structure, and the magnetostrictive columns are adhered to the aluminum plate.

[0012] Preferably, the number of the unit cells is not less than 25.

[0013] Further preferably, the number of the unit cells is 25.

[0014] Preferably, a plurality of through holes are provided on the connecting plate, and each group of magnetic field control units is arranged in the through holes;

[0015] Each group of magnetic field control units includes a magnet block and a second threaded rod; the second threaded rod is inserted into the through hole, the magnet block is sleeved on the second threaded rod close to the phononic crystal plate, and an acrylic shell is sleeved on the outside of the magnet block.

[0016] Preferably, the supporting component includes a plurality of first threaded rods, and the first threaded rods are arranged through the four sides of the connecting plate to support the magnetic field modulation control unit.

[0017] Further preferably, there are 70 groups of magnetic field control units.

[0018] Preferably, the connecting plate is made of non-magnetic material.

[0019] Further preferably, the connecting plate is made of acrylic material.

[0020] Preferably, the adjustment height of the magnetic field control unit is 45-60 mm.

[0021] Preferably, the temperature field adjustment component further includes a digitally controlled thermistor plate, and the thermoelectric sheet is pasted on the digitally controlled thermistor plate.

[0022] More preferably, there are 70 thermoelectric sheets pasted together.

[0023] Further preferably, the first threaded rods are provided in two groups.

[0024] Preferably, the fixing member includes a vertical rod, a plum blossom knob and a cross top screw fixing clamp; the vertical rod is vertically connected to the top of the optical platform, the top of the vertical rod is vertically connected to the cross top screw fixing clamp, the clamping end of the cross top screw fixing clamp clamps the temperature field adjustment control, and plum blossom knobs are installed on both sides of the cross top screw fixing clamp.

[0025] The present invention also provides a method for regulating elastic wave valley state transmission characteristics using the above-mentioned magnetic-thermal responsive phononic crystal plate device, comprising the following steps:

[0026] 1) Add elastic wave excitation through the solid mechanics physics field in the software COMSOL Multiphysics, apply the corresponding magnetic field to the phononic crystal plate through the magnetic field without current physics field, apply the corresponding temperature field to the phononic crystal plate through the solid heat transfer physics field, perform frequency domain calculation under the coupling of multiple physical fields, and finally determine its band structure;

[0027] 2) Placing the exciter on one side of the phononic crystal plate to apply elastic wave excitation, exciting elastic valley Hall interface states between each unit cell, controlling the upper and lower distances of the magnetic field modulation control, realizing dynamic regulation of the magnetic field size of the unit cell, controlling the temperature field modulation control to change the temperature size of the magnetic field modulation control, and then realizing dynamic regulation of the temperature field of the unit cell, thereby inducing a broadband elastic valley Hall interface state; by adjusting the magnetic field modulation control or the temperature field modulation control at different positions, changing the distribution position of the magnetic field or temperature field of the phononic crystal plate, dynamic regulation of the topological transmission path of the elastic valley Hall interface state is realized.

[0028] Further preferably, in step 2), the upper and lower distances of different magnet blocks are controlled by controlling the second threaded rod to adjust the magnetic field, and the temperature fields of different magnetostrictive columns are controlled by controlling the thermoelectric sheet to adjust the temperature.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention provides a magnetic-thermal responsive phononic crystal plate device, which symmetrically arranges a group of magnetic field adjustment controls above and below the phononic crystal plate, and arranges a plurality of groups of magnetic field control units in the magnetic field adjustment controls, so that each group of magnetic field control units correspondingly adjusts the magnetic field strength of a unit cell, thereby achieving dynamic regulation of the magnetic field of the unit cell, thereby changing the material properties of the unit cell, and thereby changing the band gap frequency of the phononic crystal plate; by arranging a temperature field adjustment control, and pasting a plurality of thermoelectric sheets on the temperature field adjustment control, not only each thermoelectric sheet correspondingly adjusts the temperature of a group of magnetic field control units, thereby achieving dynamic regulation of the temperature of the magnetic field adjustment control, but also indirectly changes the magnetic field adjustment. By controlling the magnetic induction intensity of the control unit, the temperature of the unit cell can be dynamically controlled, and the material properties of the unit cell can be changed, and the band gap frequency of the phononic crystal plate can be changed. Therefore, by changing the size of the magnetic field or temperature field of the phononic crystal plate to change its band gap frequency, a broadband valley Hall interface state is induced. At the same time, by changing the distribution position of the magnetic field or temperature field of the phononic crystal plate, the topological transmission path of the elastic wave valley state can be dynamically controlled, thereby realizing the control of the elastic wave transmission paths of different frequencies, solving the technical problem that it is difficult to dynamically control the frequency and topological transmission path of the elastic wave valley Hall interface state without changing the structure of the traditional topological phononic crystal.

[0031] Furthermore, the unit cell of the present invention is composed of an aluminum plate and six magnetostrictive columns to form a hexagonal honeycomb structure. This structural design helps to enhance the magnetostrictive effect of the phononic crystal plate, thereby improving the sensitivity of magnetic field regulation.

[0032] Furthermore, the number of unit cells of the present invention is set to be no less than 25, so as to better demonstrate its unique elastic wave valley state transmission characteristics.

[0033] Furthermore, each group of magnetic field control units in the present invention includes a magnet block and a second threaded rod. The magnetic field strength of the unit cell corresponding to each magnet block is adjusted by adjusting the upper and lower distances of the second threaded rod. This design enables the magnetic field control unit to accurately control the magnetic field strength of each unit cell, thereby achieving precise control of the elastic wave valley state transmission characteristics of the phononic crystal plate.

[0034] Furthermore, the connection plate is made of non-magnetic material, which avoids the interference of the connection plate on the magnetic field and ensures the accuracy and stability of the magnetic field regulation.

[0035] Furthermore, the adjustment height of the magnetic field control unit of the present invention is 45-60 mm, which helps to adjust the upper and lower distances of the magnetic field control unit as needed in practical applications, thereby achieving dynamic regulation of the magnetic field size.

[0036] Furthermore, the temperature field regulator of the present invention includes a CNC thermistor and a thermoelectric sheet. The temperature of different areas of the CNC thermistor is regulated by controlling the current of different thermoelectric sheets and accurately controlling the heating temperature, thereby providing the required working temperature for the phononic crystal plate structure, and flexibly regulating the temperature field by adjusting the different heating temperatures of different thermoelectric sheets. This design enables the temperature field regulator to accurately control the temperature of the magnetic field regulator, thereby realizing dynamic regulation of the temperature field of the phononic crystal plate.

[0037] Furthermore, in the fixing member of the present invention, by providing a plum blossom knob and a cross screw fixing clamp, the height of the numerical control thermal plate can be adjusted, thereby ensuring the stability of the numerical control thermal plate.

[0038] The present invention also provides a method for regulation using the above-mentioned magnetic-thermal responsive phononic crystal plate device, which changes the topological transmission path of the phononic crystal plate by adjusting the distribution position of the magnetic field and temperature field of the phononic crystal plate, and dynamically regulates the topological transmission path of the elastic valley state without changing the structure, thereby realizing non-contact active regulation. First, the frequency response function curve of the phononic crystal plate is determined to provide a theoretical basis for subsequent experimental verification and regulation; secondly, by controlling the magnetic field adjustment control unit and the temperature field adjustment control unit, the dynamic regulation of the magnetic field and temperature of the unit cell is realized. This regulation method is not only flexible but also accurate, and can induce a broadband elastic valley Hall interface state. At the same time, by changing the distribution position of the magnetic field or temperature field of the phononic crystal plate, the topological transmission path of the elastic valley state can be dynamically regulated, thereby realizing the control of the elastic wave transmission path of different frequencies. Without changing the structure of the phononic crystal plate, the dynamic adjustability of the frequency and transmission path of the elastic valley Hall interface state is realized, which improves the adaptability and flexibility of the phononic crystal plate in different application environments. This control method greatly improves the performance of related devices and also provides important ideas for designing intelligent and adjustable related topological wave devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of the phononic crystal plate device of the present invention;

[0040] Figure 2 This is the structural diagram of the magnetic field modulation control unit;

[0041] Figure 3a Schematic diagram of the structure of the phononic crystal plate;

[0042] Figure 3b Schematic diagram of the unit cell structure;

[0043] Figure 4 This is the structural diagram of the temperature field control unit;

[0044] Figure 5a is the unit cell energy band diagram under different magnetic fields;

[0045] Figure 5b is the energy band diagram of the magnetically responsive unit cell Dirac point;

[0046] Figure 5c It is the unit cell band diagram under different temperature fields;

[0047] Figure 5d is the temperature-responsive unit-cell Dirac point energy band diagram;

[0048] Figure 5e This is the graph of the Dirac point changing with the average magnetic field and average temperature;

[0049] Figure 5f It is the super-valley Hall interface state diagram;

[0050] Figure 6a The magnetic flux density diagram of the straight topological waveguide in response to the magnetic field;

[0051] Figure 6b The frequency response function curve of the linear topology waveguide responding to the magnetic field;

[0052] Figure 6c This is the displacement cloud diagram of the linear topological waveguide interface in response to the magnetic field;

[0053] Figure 6d The magnetic flux density diagram of the L-type topological waveguide in response to the magnetic field;

[0054] Figure 6e The frequency response function curve of the L-type topology waveguide responding to the magnetic field;

[0055] Figure 6f The displacement cloud diagram of the L-type topological waveguide interface in response to the magnetic field;

[0056] Figure 7a The temperature diagram of the straight line topological waveguide with temperature response;

[0057] Figure 7b It is the frequency response function curve of the linear topology waveguide of temperature response;

[0058] Figure 7c This is the displacement cloud diagram of the linear topological waveguide interface in response to temperature;

[0059] Figure 7d The temperature diagram of the L-type topological waveguide in temperature response;

[0060] Figure 7e The frequency response function curve of the L-type topology waveguide in response to temperature;

[0061] Figure 7f The displacement cloud diagram of the L-type topological waveguide interface in response to temperature;

[0062] Figure 8 This is a schematic diagram of the device connection;

[0063] Among them, 1-optical platform; 2-connecting plate; 3-vertical pole; 4-plum blossom knob; 5-cross screw fixing clamp; 6-acrylic shell; 7-second threaded rod; 8-first threaded rod; 9-rope; 10-thermoelectric sheet;

[0064] 11-CNC thermal plate; 12-magnetostrictive column; 13-aluminum plate; 14-magnet block; 15-unit cell; 16-vibrator. DETAILED DESCRIPTION

[0065] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0066] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0067] The present invention provides a magnetic-thermal responsive phononic crystal plate device, comprising: an optical platform 1, on which two vertical rods 3 and four second threaded rods 7 are threadedly installed, and a cross screw fixing clamp 5 that can reciprocate up and down is slidably installed outside the two vertical rods 3, and the two are vertically distributed, and the two cross screw fixing clamps 5 are connected to a numerical control thermal sensitive plate 11, and 70 thermoelectric sheets 10 are adhered to the numerical control thermal sensitive plate 11; two upper and lower connecting plates 2 made of acrylic material are fixed by the four second threaded rods 7, and the connecting plates 2 suspend ropes to fix the phononic crystal plate, and the phononic crystal plate is composed of 25 unit cells 15; the connecting plates 2 are respectively connected and fixed with 70 first threaded rods 8, and the first threaded rods 8 are connected to an acrylic shell 6, and a fixed magnet block 14 is loaded inside the acrylic shell 6.

[0068] Optionally, the unit cell 15 is composed of 6 magnetostrictive columns 12 and an aluminum plate 13 .

[0069] Optionally, the two upright poles 3 are externally provided with slidable cross screw fixing clamps 5 parallel to the main structure, and plum blossom knobs 4 are respectively provided on both sides of the two cross screw fixing clamps 5 .

[0070] Optionally, the phononic crystal plate is fixed by ropes and is in a suspended state, and the interior of the phononic crystal plate is composed of 25 unit cells 15 .

[0071] Optionally, the four corners of the connecting plate 2 are fixed by four second threaded rods 7, and each connecting plate 2 is respectively connected to and fixed with 70 first threaded rods 8, and the first threaded rods 8 are connected to the acrylic shell 6, and the acrylic shell 6 is internally loaded with a fixed magnet block 14.

[0072] The present invention is further described in detail below with reference to the accompanying drawings and embodiments:

[0073] The present invention proposes a magnetic-thermal responsive phononic crystal plate device, comprising: an optical platform 1, on which two vertical rods 3 and four second threads 7 are threadedly installed, and a cross screw fixing clamp 5 that can reciprocate up and down is slidably installed outside the two vertical rods 3, and the two are vertically distributed, and the two cross screw fixing clamps 5 are connected to a numerical control thermal sensitive plate 11, and 70 thermoelectric sheets 10 are adhered to the numerical control thermal sensitive plate 11; the upper and lower connecting plates 2 made of acrylic material are fixed by the four second threaded rods 7, and the connecting plates 2 suspend ropes to fix the phononic crystal plate, and the phononic crystal plate is composed of 25 unit cells 15; the connecting plates 2 are respectively connected and fixed with 70 first threaded rods 8, and the first threaded rods 8 are connected to an acrylic shell 6, and a fixed magnet block 14 is loaded inside the acrylic shell 6.

[0074] As shown in FIG3 , a unit cell is composed of six magnetostrictive columns 12 and an aluminum plate 13 ; the phononic crystal plate is fixed by ropes and is suspended in the air, and the inside is a phononic crystal plate composed of 25 unit cells 15 .

[0075] like Figure 4 As shown, the two uprights 3 are externally provided with cross screw fixing clamps 5 which can slide up and down and are parallel to the main structure, and plum blossom knobs 4 are respectively provided on both sides of the two cross screw fixing clamps 5 .

[0076] like Figure 2 As shown, the four corners of the two connecting plates 2 are fixed by four second threaded rods 7, and each connecting plate 2 is respectively connected and fixed with 70 first threaded rods 8, and the threaded rods are connected to the acrylic shell 6, and the acrylic shell 6 is loaded with a fixed magnet block 14.

[0077] In addition, according to an embodiment of the present invention, the steps of the operating method are as follows:

[0078] 1. Add elastic wave excitation through the solid mechanics physics field in the software COMSOL Multiphysics, apply the corresponding magnetic field to the phononic crystal plate through the magnetic field without current physics field, apply the corresponding temperature field through the solid heat transfer physics field, perform frequency domain calculation under the coupling of multiple physical fields, and finally determine its frequency response function curve;

[0079] 2. Place the exciter on one side of the phononic crystal plate to apply elastic wave excitation, stimulate the elastic wave valley Hall interface state between each unit cell, and control the upper and lower distances of different magnet blocks 14 by controlling the first threaded rod 8 to adjust the magnetic field size. Control the temperature field of different magnetostrictive columns 12 by controlling the thermoelectric sheet 10 to adjust the temperature size and induce a broadband elastic wave valley Hall interface state. At the same time, without changing the structure, the dynamic adjustability of the elastic wave valley state topological transmission path by magnetic-thermal dual excitation is achieved by adjusting the distribution position of the magnetic field and the temperature field.

[0080] Example 1

[0081] Bandgap regulation: Select the unit cell structure shown in Figure 3, use COMSOL Multiphysics software for simulation calculation, and establish the corresponding model in the software according to the material and size parameters. Add Floquet periodic boundary conditions to the solid mechanics physical field, apply the magnetic field through the magnetic field without current physical field, and apply the temperature field through the solid heat transfer physical field. Calculate the characteristic frequency under the coupling of multiple physical fields. When different magnetic fields are set in adjacent magnetostrictive columns 12, the background magnetic field is set to 0Oe, the background temperature is 25°C, the average magnetic field is 2000Oe, and the adjacent magnetic field difference is 2000Oe. The obtained band structure is as follows: Figure 5aAs shown, the band gap is within the range of 9680-10900 Hz. When the magnetic fields of adjacent magnetostrictive columns 12 are the same, the band gap is closed and the Dirac point appears at 10300 Hz, as shown in FIG. Figure 5b When different temperature fields are set in adjacent magnetostrictive columns 12, the average magnetic field is 2000Oe, the average temperature is 40°C, and the temperature difference is 60°C, the obtained band structure diagram is as shown Figure 5c As shown, the band gap is in the range of 9800-10880 Hz. When the temperatures of adjacent magnetostrictive columns 12 are the same, the band gap is closed and the Dirac point is at 10500 Hz. Figure 5d As shown; Figure 5e The graph of the Dirac point changing with the average magnetic field and average temperature shows that the Dirac point increases with the increase of the average temperature and the average magnetic field. The two unit cells 15 with different magnetic fields are constructed into beams, and the characteristic frequencies are calculated to obtain the valley Hall interface state diagram, as shown in Figure 5f As shown in the figure, as the average magnetic field increases, the characteristic frequency corresponding to the valley Hall interface state increases. Therefore, this device can be used to realize non-contact active regulation of the phononic crystal band structure and valley Hall interface state under magnetic-thermal multi-field coupling, and construct a topological phononic crystal that can be actively regulated without changing its structure, thereby enhancing its overall dynamic controllability.

[0082] Example 2

[0083] Valley Hall interface state: Select a supercell structure composed of 25 unit cells 15 as shown in Figure 3, use COMSOL Multiphysics software for simulation calculation, and establish a corresponding model in the software according to material and size parameters. Add elastic wave excitation to the solid mechanics physical field, apply a magnetic field through the magnetic field without current physical field, and apply a temperature field through the solid heat transfer physical field. Set different magnetic fields or temperature fields on adjacent magnetostrictive columns 12, respectively, and perform frequency domain calculations under the coupling of multiple physical fields. After obtaining the frequency response function curve, change the phononic crystal plate waveguide transmission path by adjusting the magnetic field or temperature field, and dynamically control the elastic wave valley state topological transmission characteristics without changing the structure, so as to achieve non-contact active control; Figure 6a Shown is the magnetic flux density diagram of the straight topological waveguide in response to the magnetic field; Figure 6b This is the frequency response function curve of the linear topological waveguide of the magnetic field response. It can be seen that A is obviously higher than B in the shaded area. Figure 6c This is the displacement cloud diagram of the linear topological waveguide interface in response to the magnetic field. It can be seen that the displacement is concentrated only near the linear path and decays rapidly until it disappears after leaving the path. Figure 6d The figure shows the magnetic flux density diagram of changing the topological waveguide path from a linear waveguide to an L-shaped waveguide by actively adjusting the height of the magnet block 14 to change the magnetic field of the magnetostrictive column 12; Figure 6eThis is the frequency response function curve of the L-type topological waveguide in response to the magnetic field. It can also be seen that A is significantly higher than B in the shaded area. Figure 6f This is the displacement cloud diagram of the L-shaped topological waveguide interface in response to the magnetic field. It can be seen that the displacement is concentrated near the L-shaped path and decays rapidly until it disappears after leaving the path. Figure 7a to Figure 7f As shown, the topological waveguide path is changed by actively adjusting the thermoelectric sheet 10 to change the temperature field of the magnetostrictive column 12, such as Figure 7a As shown, it is the temperature diagram of the linear topological waveguide of temperature response, and then we can get Figure 7b The temperature response of the straight-line topology waveguide frequency response function curve shown in the figure and Figure 7c The displacement cloud diagram of the straight topological waveguide interface shown in the figure is changed from the temperature-responsive straight topological waveguide to the temperature-responsive L-type topological waveguide. Figure 7d The temperature field distribution diagram shown in Figure 7e The frequency response function graph and Figure 7f The interface displacement cloud diagram is shown. Therefore, this device can realize non-contact active regulation of the elastic valley state topological waveguide path of the phononic crystal plate under magnetic-thermal multi-field coupling, and actively control the band gap, valley Hall interface state and other characteristics of the phononic crystal by changing the magnetic field or temperature field. It has a simple structure and is easy to operate, solving the current problem of dynamically regulating the elastic valley state topological transmission of the phononic crystal elastic wave without changing the structure.

[0084] like Figure 8 As shown, first, four second threaded rods 7 are rotated on the optical platform 1 to fix two acrylic connecting plates 2 to appropriate positions. The four second screw rods 7 can be rotated to adjust the height of the connecting plate 2 and the first threaded rods 8 and the magnet block 14 connected and fixed to the connecting plate 2. Then, two cross top screw fixing clamps 5 connected to the screw rods 7 and capable of reciprocating up and down can be used to connect the CNC thermal plate 11. The height of the CNC thermal plate 11 can be adjusted by rotating the plum blossom knob 4. A rope 9 is hung from the connecting plate 2 to fix the phononic crystal plate. The connecting plate 2 is respectively connected and fixed with 70 first screw rods 8. The first screw rods 8 are connected to the acrylic shell 6. The acrylic shell 6 is loaded with a fixed magnet block 14.

[0085] For the requirements of constructing magnetic field and temperature field of different topological interface states, it is only necessary to adjust the height of the first spiral rod 8 connected to different magnet blocks 14 to construct different magnetic field environments required by different magnetostrictive columns 12. The actual magnetic field data is measured by Gauss meter CH150. By controlling the current of different thermoelectric sheets 10, the heating temperature is precisely controlled to adjust the temperature of different areas of the CNC thermal plate 11 to provide the required working temperature for the phononic crystal plate structure, and by adjusting the different heating temperatures of different thermoelectric sheets 10, the temperature field can be flexibly controlled. The actual temperature data is obtained by infrared thermal imager Uni-t 260A, realizing non-contact active and flexible control of the position and frequency of elastic wave topological interface states.

[0086] Conduct transmission experiments on elastic wave topological interface states, generate sweep frequency excitation signals through control system IM1208H, and amplify them through power amplifier DPM1500A before acting on exciter PME50. The input and output signals can be recorded by two accelerometers C02A00 and data logger IM1208H, and the excitation frequency can be swept:

[0087] T l =20log(A out / A in )

[0088] The frequency response function can be obtained, where A out and A in are the output amplitude and input amplitude respectively.

[0089] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0090] The above is only the technical idea of ​​the present invention, which enables those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied for herein, and any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention will fall within the scope of protection of the claims of the present invention.

Claims

1. A magnetic-thermal responsive phononic crystal plate device, characterized in that: It comprises an optical platform (1) and a phononic crystal plate, wherein the phononic crystal plate comprises a plurality of periodically distributed unit cells (15); A group of magnetic field adjustment controls are symmetrically arranged above and below the phononic crystal plate, the magnetic field adjustment controls are connected to the optical platform (1) via a supporting component, the magnetic field adjustment controls include a connecting plate (2) and a plurality of groups of magnetic field adjustment units, each group of magnetic field adjustment units is arranged on the connecting plate (2), and each group of magnetic field adjustment units correspondingly adjusts the magnetic field intensity of a unit cell (15); a temperature field adjustment control is arranged between the phononic crystal plate and the magnetic field adjustment control above it, the temperature field adjustment control is connected to the optical platform (1) via a fixing member, the temperature field adjustment control includes a plurality of thermoelectric sheets (10), and each thermoelectric sheet (10) correspondingly adjusts the temperature of a group of magnetic field adjustment units; One side of the unit cell (15) is connected to an exciter (16), and the exciter (16) is connected to a power supply; the exciter (16), the magnetic field modulation control unit, the temperature field modulation control unit, the phononic crystal plate and the power supply form a closed circuit loop.

2. A magnetic-thermal responsive phononic crystal plate device according to claim 1, characterized in that: The unit cell (15) is composed of an aluminum plate (13) and six magnetostrictive columns (12) to form a hexagonal honeycomb structure, and the magnetostrictive columns (12) are adhered to the aluminum plate (13).

3. The magnetic-thermal responsive phononic crystal plate device according to claim 1, characterized in that: The number of the unit cells (15) is not less than 25.

4. The magnetic-thermal responsive phononic crystal plate device according to claim 1, characterized in that: The connecting plate (2) is provided with a plurality of through holes, and each group of magnetic field control units is arranged in the through holes; Each group of magnetic field control units comprises a magnet block (14) and a second threaded rod (8); the second threaded rod (8) is inserted into the through hole, the magnet block (14) is sleeved on the second threaded rod (8) on a side close to the phononic crystal plate, and an acrylic shell (6) is sleeved on the outside of the magnet block (14).

5. The magnetic-thermal responsive phononic crystal plate device according to claim 1, characterized in that: The supporting component comprises a plurality of first threaded rods (7), wherein the first threaded rods (7) are arranged to penetrate around the connecting plate (2) and are used to support the magnetic field modulation control unit.

6. The magnetic-thermal responsive phononic crystal plate device according to claim 4, characterized in that: The connecting plate (2) is made of non-magnetic material.

7. The magnetic-thermal responsive phononic crystal plate device according to claim 1, characterized in that: The adjustment height of the magnetic field control unit is 45-60 mm.

8. The magnetic-thermal responsive phononic crystal plate device according to claim 1, characterized in that: The temperature field adjustment component also includes a digitally controlled thermal plate (11), and the thermoelectric sheet (10) is adhered to the digitally controlled thermal plate (11).

9. The magnetic-thermal responsive phononic crystal plate device according to claim 1, characterized in that: The fixing member comprises a vertical rod (3), a plum blossom knob (4) and a cross top screw fixing clamp (5); the vertical rod (3) is vertically connected to the top of the optical platform (1); the top of the vertical rod (3) is vertically connected to the cross top screw fixing clamp (5); the clamping end of the cross top screw fixing clamp (5) clamps the temperature field adjustment control unit; and plum blossom knobs (4) are installed on both sides of the cross top screw fixing clamp (5).

10. A method for regulating elastic wave valley state transmission characteristics using a magnetic-thermal responsive phononic crystal plate device as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: 1) Determine the band structure of the phononic crystal plate by applying elastic wave excitation, magnetic field and temperature field to the phononic crystal plate; 2) placing an exciter (16) on one side of the phononic crystal plate to apply elastic wave excitation, exciting elastic valley Hall interface states between each unit cell (15), controlling the upper and lower distances of the magnetic field modulation control unit to achieve dynamic regulation of the magnetic field size of the unit cell (15), controlling the temperature field modulation control unit to change the temperature size of the magnetic field modulation control unit, and then achieving dynamic regulation of the temperature field of the unit cell (15), thereby inducing a broadband elastic valley Hall interface state; by adjusting the magnetic field modulation control unit or the temperature field modulation control unit at different positions, changing the distribution position of the magnetic field or temperature field of the phononic crystal plate, dynamic regulation of the topological transmission path of the elastic valley Hall interface state is achieved.

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