604 results about "Metamaterial" patented technology

The technology described herein is directed towards one or more modular metasurfaces arranged with unit cells for sound absorption, in which the unit cells are based on Helmholtz resonators that are deployed proximate to a server, without substantially obstructing airflow from the server fan(s). Each sound absorbing unit-cells is designed and constructed based on a specific resonance frequency, and includes a neck portion and air chamber dimensioned to resonate at the desired resonance frequency and thereby inverse phase cancel corresponding narrowband frequencies of incoming sound waves. The metasurfaces can be arranged in a modular frame structure of surrounding unit cells, positioned behind the server's fan(s), with an opening in the frame structure to facilitate airflow therethrough, without obstructing or substantially obstructing the airflow to the surrounding environment.

The invention relates to a radial frequency-doubled sound filtering metamaterial and a topological optimization design method thereof.The radial frequency-doubled sound filtering metamaterial comprises scatterers which are arranged on a base body and distributed in a concentric circle mode, and the topological optimization design method comprises the following steps that a two-dimensional axial symmetry model is established, the two-dimensional axisymmetric model corresponds to the cross section of the radial frequency-doubled sound filtering metamaterial in the radius direction and comprises periodically arranged unit structures, and each unit structure comprises a main board and a square design domain; a Floquet periodic boundary condition is applied to parallel boundaries of a unit structure in the radius direction, other boundaries are set as free boundaries, a genetic algorithm is adopted to carry out iterative optimization on the material distribution topology of a square design domain, the optimal material distribution topology of the square design domain is obtained, and then the final optimized shape of the radial double-frequency sound filtering metamaterial is obtained. Compared with the prior art, the invention has the advantages of capability of realizing omni-directional sound wave frequency doubling filtering, high design reliability and the like.

The invention belongs to the technical field of radar wave-absorbing materials, and discloses a double-sided wave-absorbing broadband stealth composite material and a preparation method thereof. The broadband stealth composite material with the double-sided wave absorbing function comprises a non-metal-based composite material body and at least five metamaterial layers arranged in the thickness direction of the non-metal-based composite material body at intervals. The number of the metamaterial layers is an odd number, a middle metamaterial layer is arranged in the middle of the metamaterial layers in the thickness direction, and the rest metamaterial layers are symmetrically distributed on the two sides of the middle metamaterial layer; the metamaterial layer comprises conductive pattern units which are periodically arranged; the relative dielectric constant of the nonmetal-based composite material body is not greater than 10; the double-sided wave-absorbing broadband stealth composite material does not contain a metal reflecting layer. When electromagnetic waves with the frequency of 1-18 GHz vertically enter the material, the transmissivity of the material is small (smaller than-13 dB, namely smaller than 5%), and meanwhile the material has low reflectivity in a broadband. And the preparation method is simple to operate and easy to realize large-scale production.

The technology described herein is directed towards a metasurface arranged with unit cells for broadband and / or multiband sound absorption, in which the unit cells are based on the principles of Helmholtz resonators. Deeply subwavelength sound absorbing unit cells are designed and constructed based on desired resonance frequencies. Each unit cell includes a neck portion and air chamber dimensioned to resonate at a desired resonance frequency and thereby inverse phase cancel corresponding frequencies of incoming sound waves. Differently designed and arranged subgroups of unit cells are part of the metasurface, which can be positioned proximate to a noise source. As practical examples, the metasurface or multiple metasurfaces can be placed near or wrapped around a computer server or rack of servers to absorb fan noise. The metasurface components (including the unit cells) can be printed by a 3D printer to result in a thin, light-weight, and cost effective noise absorbing metasurface.

The invention discloses a bifunctional chiral metamaterial surface capable of switching polarization conversion and wave absorption, and belongs to the technical field of electromagnetic metamaterials. The method is used for solving the problem that most existing chiral super-structure surfaces cannot realize dynamic adjustability and quantitative controllability and cannot have dual functions of polarization conversion and wave absorption at the same time. The super-structure surface unit structure is composed of a graphene film layer, a gold-vanadium dioxide resonance layer, a silicon dielectric layer and a bottom-layer continuous gold film. Switching of two functions of polarization conversion and wave absorption is realized by changing the conductivity of vanadium dioxide; polarization conversion and dynamic regulation and control of the wave absorbing efficiency are realized by changing the Fermi level of the graphene; quantitative controllability of polarization conversion and a wave absorbing function is realized by controlling a function weighting function. Besides, the chiral super-structure surface also has the advantages of incident angle robustness, small thickness and small size, has double functions of broadband, and has potential application value in the fields of optical devices, communication equipment, biomedical sensors and the like.

A polarization conversion transmission type reconfigurable metamaterial structure with amplitude-phase independent regulation and control is formed by copying and translating n * n basic units, and each basic unit comprises three dielectric layers, five metal layers and two air layers; the dielectric layers comprise a first dielectric layer, a second dielectric layer and a third dielectric layer from top to bottom; a first air layer is arranged between the first dielectric layer and the second dielectric layer, and a second air layer is arranged between the second dielectric layer and the third dielectric layer; the amplitude regulation and control layer is located on the upper surface of the first dielectric layer, and the amplitude regulation and control bias circuit layer is located on the lower surface of the first dielectric layer; the polarization conversion phase regulation and control layer is located on the upper surface of the second dielectric layer, and the polarization conversion phase regulation and control bias circuit layer is located on the lower surface of the second dielectric layer; the polarization gate layer is located on the upper surface of the third dielectric layer. According to the invention, efficient electromagnetic regulation and control in a transmission mode are realized, independent regulation and control in two dimensions of amplitude and phase are realized, and unification of high transmissivity and accurate regulation and control in a microwave frequency band is realized.

The invention discloses an ultra-wideband RCS (radar cross section) reduction metasurface with mixed wave absorption and diffuse scattering and a wave-transparent window, and belongs to the technical field of electromagnetic metamaterials. The metasurface adopts a four-layer cascade structure and comprises a first layer of polarization conversion structure, a second layer of 2.5 D lossy structure, a third layer of Jerusalem cross-shaped lossy structure and a fourth layer of frequency selective surface structure. By loading a lumped resistor at a specific position and adopting a metal through hole interconnection technology, dual functions of radar cross section reduction in a 1-20GHz ultra-wideband and low insertion loss wave transmission in a 8-12GHz frequency band are realized. The structure of each layer adopts a highly symmetrical design and has the characteristic of polarization insensitivity, and meanwhile, by optimizing interlayer air gaps and dielectric material selection, the structure compactness is realized on the premise of ensuring the performance. The method has important application value in the aspect of integration of stealth equipment and a communication system.

The invention discloses a non-magnetic passive space nonreciprocal antenna housing based on an artificial electromagnetic metamaterial, and relates to the technical field of stealth materials, the non-magnetic passive space nonreciprocal antenna housing comprises antenna housing units which are periodically spliced in a plane, and each antenna housing unit comprises two dielectric substrates which are vertically crossed with each other; artificial microstructure units are arranged on the upper surface and the lower surface of the dielectric substrate; wherein the artificial microstructure unit arranged on the upper surface of the dielectric substrate comprises a double-opening SRR ring, the artificial microstructure unit arranged on the lower surface of the dielectric substrate comprises an asymmetric square opening ring, and the centers of the double-opening SRR ring and the asymmetric square opening ring are asymmetric. The technical problems that in the prior art, a non-reciprocal super-electromagnetic surface needs external magnetic bias or an external power source, preparation is complex, and integration is difficult are solved.

A polarization selective device (10) of this invention is a polarization selective device that receives an incident electromagnetic wave and emits an electromagnetic wave, and includes a plurality of metamaterial elements (13), wherein among the plurality of metamaterial elements, at least two metamaterial elements are arranged in parallel to each other, each of the two metamaterial elements includes gaps (132), a shape of each of the two metamaterial elements has reflection symmetry, one of the two metamaterial elements includes the gaps in one direction, and the other of the two metamaterial elements includes the gaps in another direction vertical to the one direction. This invention can thus provide a polarization selective device capable of dynamically controlling selection of a polarized wave of an electromagnetic wave.

The invention belongs to the technical field related to structure optimization design, and discloses a topological optimization method and device for a metamaterial microstructure capable of bearing a band gap, and the method comprises the steps: (1) respectively defining an interpolation penalty coefficient of a Young modulus for the homogenization analysis of the microstructure and the band gap problem of an energy band structure according to the performance analysis of the microstructure, calculating an interpolation penalty coefficient of the mass density; (2) carrying out homogenization analysis of the microstructure based on dynamics to obtain equivalent physical property parameters and determine equivalent material modulus; (3) defining an irreducible first Brillouin region wave vector path of the microstructure based on the geometric symmetry constraint of the microstructure, and further calculating a band gap quality factor between adjacent energy band curves of the microstructure; and (4) establishing a topological optimization model which takes the equivalent modulus as a grading constraint and takes band gap quality factor maximization as a target, and performing iterative optimization based on the topological optimization model to obtain an optimal microstructure configuration. According to the invention, efficient and stable design of the microstructure is realized.

The invention discloses a thermal metamaterial-based satellite component layout-deck structure integrated optimization design method, which belongs to the technical field of satellite thermal management, and comprises the following steps: carrying out geometric description on components, and carrying out interference calculation between the components; selecting a planar four-node rectangular unit discrete design domain, and representing a component temperature field as an interpolation relation of node temperature; designing an optimization target and constraint, converting the optimization target and constraint into a standard optimization column formula, and searching an optimal component layout scheme; the method comprises the following steps: carrying out topological optimization design on a satellite deck structure on the basis of a thermal metamaterial design idea, determining a thermal metamaterial function type and dividing a local deck design domain; discretizing each design unit, carrying out topological optimization design on the discretized design units, and searching a microstructure with the highest matching degree between the macroscopic equivalent heat conduction tensor and the theoretical heat conduction tensor of the central position of the design unit; and assembling the microstructure to obtain the deck structure. According to the invention, global thermal management and local thermal management of the satellite cabin can be realized.

The invention belongs to the technical field of electromagnetic wave-absorbing materials, and particularly relates to a zero-power absorption type adjustable metasurface composite material and a preparation method thereof. Comprising a panel, a square-ring-shaped metal layer, a cross-shaped metal layer, an electric control metamaterial, a resistive film and a reflecting back plate from top to bottom in sequence, a core layer is arranged among the square metal layer, the cross curve metal layer, the electric control metamaterial, the resistive film and the reflecting back plate; the electric control metamaterial comprises second structure units which are periodically arranged along x and y directions and contain PIN diodes, and the PIN diodes are embedded into the structure; the cross curve metal layer and the square metal layer respectively comprise a third structure unit and a fourth structure unit which are periodically arranged along the x direction and the y direction. Through a cascade structure formed by the electric control metamaterial, the cross-shaped metal layer and the square ring-shaped metal layer, when the PIN diode is switched off, the wave absorbing state is presented, when the PIN diode is switched on, the reflecting state is presented, and electromagnetic waves are absorbed under the condition that bias voltage is not applied.

The application discloses a heat pipe structure based on metamaterial and a processing method, relates to the technical field of lightweight multifunctional structures, and the heat pipe structure comprises a metal structure, a sealed cavity is arranged in the metal structure, a filling lattice is arranged in the sealed cavity, and an unfilled area is arranged in the middle of the filling lattice; the filling lattice comprises at least two lattice layers with different porosities, and the porosity of the filling lattice decreases from the unfilled area to the edge of the sealed cavity. The integration of the metal solid structure or the honeycomb sandwich structure and the specific heat pipe structure is realized, the number of heat transfer interfaces is greatly reduced, and the heat transfer efficiency is greatly improved.

The invention belongs to the technical field of metamaterials, and particularly relates to an adjustable wave-absorbing and reflecting integrated metamaterial structure which comprises a plurality of basic units arranged in a periodic array mode, and each basic unit comprises a resonance unit, a dielectric layer and a reflecting plate which are sequentially arranged in a stacked mode. The dielectric layer can be deformed, so that a cavity is formed between the dielectric layer and the reflecting plate or the dielectric layer is tightly attached to the reflecting plate; each resonance unit comprises four arc-shaped sections which are sequentially connected with one another, the four arc-shaped sections are arranged in a central symmetry mode, sharp corner parts extending towards the center of the resonance unit are formed at the connecting positions of the tail ends of the adjacent arc-shaped sections, and a gap is formed between every two opposite sharp corner parts. According to the invention, the reconfigurability is good, the use flexibility and deformability are very high, the state can be conveniently adjusted according to the actual use requirement so as to switch the use mode, and the 4.9 GHz-16.3 GHz broadband wave absorption or complete reflection function can be realized.

The invention discloses an aerogel metamaterial capable of switching electromagnetic wave absorption and deflection reflection wave beam and a preparation method thereof, and the preparation method is characterized in that a metamaterial unit with a loose structure is arranged and comprises a first layer of rectangular pyramid, a second layer of quadrangular frustum pyramid, a third layer of quadrangular frustum pyramid and an internal pyramid cavity; the first layer of rectangular pyramid, the second layer of quadrangular frustum pyramid, the third layer of quadrangular frustum pyramid and the internal pyramid cavity are on the same center line; the bottom surface of the internal pyramid cavity is close to the bottom surface of the third-time quadrangular frustum pyramid, and the vertex of the internal pyramid cavity is close to the vertex of the first-layer quadrangular pyramid; the preparation method comprises the following steps: pouring mixed dispersion liquid containing conductive / magnetic functional components and cellulose microfibers into a mold manufactured according to a set structure, freezing, and then freeze-drying to obtain the metamaterial unit. The obtained aerogel metamaterial solves the problems that the effective absorption bandwidth of aerogel with adjustable electromagnetic wave absorption performance is difficult to substantially break through, and the aerogel cannot have both electromagnetic wave absorption performance and deflection reflection beam performance at the same time.

The invention provides an inverted-F antenna and wearable equipment, and relates to the technical field of antennas. The inverted-F antenna comprises an inverted-F antenna body and a metamaterial array, the inverted-F antenna body comprises a radiator, and the radiator transmits electromagnetic waves to a target radiation direction; and the metamaterial array is arranged on one side, deviating from the target radiation direction, of the radiator so as to suppress the reverse radiation of the inverted-F antenna. According to the invention, the metamaterial array used for suppressing the reverse radiation of the inverted-F antenna is arranged on the side, deviating from the target radiation direction, of the radiator of the inverted-F antenna body, so that the directional focusing of the main beam of the inverted-F antenna is realized, the reverse radiation is suppressed, the SAR of the wearable device comprising the inverted-F antenna is reduced, the electromagnetic radiation exposure of a user is reduced, and the user experience is improved. And the use safety of the wearable equipment is improved.

The invention provides a metamaterial surface structure design method based on a self-encoding diffusion model, and the method comprises the steps: encoding a high-dimensional surface structure to a potential space, and inputting the encoded surface structure to a diffusion model, thereby greatly reducing the training time of the model; in a denoising stage of the diffusion model, a cross attention mechanism is used to introduce a spectral vector, a reconstructed surface structure is generated, a pre-trained forward prediction network is used to output a predicted spectral vector, an error between the predicted spectral vector and a real spectral vector is calculated, and the error is used as a main loss to train a self-encoding diffusion model. Therefore, the model can deeply learn the corresponding relation between the spectral vector and the surface structure of the nano photon metamaterial, and reverse design is realized. After the spectrum vectors in the test set are reversely designed by using the design method, the generated reconstructed surface structure passes through the forward prediction network, the obtained predicted spectrum is highly fitted with the real spectrum, and the problem that the design diversity and the accuracy are difficult to balance in the reverse design in the prior art is solved.

An active infrared system may include at least one metamaterial optical element. The active infrared system may also include at least one lens assembly optically aligned with the at least one metamaterial optical element. The active infrared system may also include at least one active camera optically aligned with the at least one metamaterial optical element. The at least one metamaterial optical element of the active infrared system may also be configured with at least a reflection mode for reflecting at least one light waveband reflected by a remote object and a transmission mode for transmitting a uniform background light that is wider than the at least one light waveband reflected by the remote object.

A porous wick based on a conformal metal metamaterial comprises a pipe body, a wick body is arranged in the pipe body in a sleeved mode, the wick body comprises a conformal design porous structure, gaps of the porous structure are filled with the metal metamaterial, and a design method of the porous structure comprises the steps that mesh generation is conducted on a model of the wick body, and after mesh generation, the wick body is made of the metal metamaterial. A conformal design method is adopted to fill each gap of a wick with a metal metamaterial, the wick is prepared through a 3D printing manufacturing technology, the unit cell geometrical shape of the metamaterial can be regulated and controlled according to the actual situation of a porous structure, the metal metamaterial is introduced, the highly optimized porous structure is adopted, and the performance of the wick is improved. The capillary action and the liquid transmission efficiency of the wick are remarkably improved, the parameters such as porosity, unit cell size and microstructure type can be adjusted, and the capillary capacity and the fluid flowing path are optimized.

The invention provides a matrix type foam wave-absorbing material based on a coding metamaterial concept, and the matrix type foam wave-absorbing material based on the coding metamaterial concept comprises a bottom plate and units which are periodically arranged on the bottom plate. The information coding concept is introduced into metamaterial design, discrete units are arranged according to a specific coding rule, and electromagnetic waves are flexibly regulated and controlled while the inherent advantages of a foam wave-absorbing material are reserved. Besides, different wave-absorbing units are coded and combined, so that multi-band synergistic absorption can be realized, the overall density of the material can be reduced by optimizing unit distribution, the design concept breaks through a single performance optimization mode of a traditional material, and a new paradigm is provided for developing a novel wave-absorbing material with multiple functions of invisibility, bearing, sensing and the like. And the structure is simple, the preparation method is simple and convenient, modular assembly is easy, and engineering application is facilitated.

The present invention relates to a pentamode metamaterial (1) having a plurality of unit cells (2), each unit cell (2) comprising: − a plurality of groups (3) of elongated elements (4), − at least a central core (5) from which elongated elements (4) branch off in a plurality of directions, − a plurality of core portions (5'), each core portion (5') being spaced from said central core (5) and from the other core portions (5'). For each unit cell (2): − each elongated element (4) develops between the central core (5) and one of said core portions (5'), − the elongated elements (4) of each group (3) of elongated elements branch off from the same side and / or surface of the central core (5), are spaced from each other and run parallel to each other, − the elongated elements (4) of each group (3) of elongated elements extend in a direction or in a sheaf of directions transverse to a direction or to a bundle of directions of the elongated elements (4) of one or more close or adjacent groups (3) of elongated elements, − optionally, the mass is concentrated at the central core (5). The repetition of unit cells (2) in space defines a two- or three-dimensional pentamode metamaterial structure (1).

The invention provides a sound amplification device based on an M-H metamaterial and a sound transmission method using the sound amplification device, the sound amplification device at least comprises an upper shell, a lower shell and a waveguide located between the upper shell and the lower shell, and the waveguide is made of the Mie metamaterial; the waveguide comprises an outer wall, a plurality of sound wave inlets are formed in the outer wall, and the upper shell, the lower shell and the outer wall enclose a waveguide space; a through hole penetrating through the waveguide and the upper shell is formed in the waveguide space, and the through hole is a sound wave outlet in the sound amplification device; the waveguide comprises a plurality of fan parts which are arranged around the through hole in a circumferential radiation manner; a waveguide channel penetrating through the sound wave outlet and the sound wave inlet is formed between the adjacent fan parts; the control current of the sound source is determined by the size of the sound amplifying device and the scattering distribution condition of the sound amplifying device in different resonance modes, the sound at the sound wave outlet is larger than the sound at the sound source in energy level, and an included angle exists in the propagation direction. By determining the control current at the sound source which is most matched with the size of the sound amplifying device, the sound propagation control with low cost, high accuracy and wide application range is realized.

The invention belongs to the technical field of magnetic field shielding, and discloses an electromagnetic wave absorbing material and device. The electromagnetic wave absorbing material provided by the invention comprises a first skin glass fiber reinforced plastic, a core layer medium, an impedance metamaterial, a second skin glass fiber reinforced plastic and a reflecting layer which are sequentially arranged from top to bottom, the impedance metamaterial comprises a dielectric film and two hollowed-out surface impedance metamaterial layers with different periodic structures, wherein the two hollowed-out surface impedance metamaterial layers are located on the front face and the back face of the dielectric film. The electromagnetic wave absorbing device provided by the invention comprises the electromagnetic wave absorbing material. The high-strength wave-absorbing material has high structural strength and also has relatively good wave-absorbing performance.

The invention relates to the technical field of artificial intelligence and metamaterial research, in particular to a metamaterial reverse design method and system meeting multiple conditions. The invention provides a metamaterial reverse design method meeting multiple conditions, which comprises the following steps of: firstly, generating a metamaterial unit cell picture by using an initial variable combination randomly generated in a range, and then inputting the picture into a trained prediction model to obtain a dispersion graph and transmission loss data. And finally, substituting the prediction result into the fitness function, if the requirement is met, outputting the variable and the prediction result, otherwise, applying penalty to carry out iteration until the maximum number of iterations is reached. According to the invention, rapid design of the metamaterial is realized, the designed metamaterial has a wide band gap, and ideal target band gap and transmission loss conditions can be obtained; according to the invention, the deep learning model is utilized to meet the metamaterial reverse design of the required band gap and transmission loss conditions, and the multi-target performance requirement is met. According to the method, the problems that in the prior art, a traditional metamaterial design method depends on experience-driven iterative optimization and is limited by calculation efficiency, high-dimensional parameter space is difficult to efficiently explore, and complex multi-target performance requirements are difficult to meet are solved.

The application relates to the technical field of elastic wave metamaterials, in particular to an elastic wave strong localization plate beam structure based on gradient coupling. The structure comprises multiple resonance units, a stacking structure and a truncated defect structure; the resonance units are sequentially arranged along a first direction to form scale coupling chains, and the coupling stiffness between adjacent resonance units monotonously changes along the direction according to a geometric scale law; the stacking structure is formed by stacking multiple scale coupling chains along a second direction; the truncated defect structure is located at the right end of the middle layer of the stacking structure, and a local vacancy is formed by removing a resonance unit or a connecting plate at the end of the middle layer, which is used for inducing an enhanced localized state. The gradient coupling mechanism is adopted, the wave function space redistribution effect generated by the geometric scale law is utilized, the elastic wave energy shows stronger localization characteristics at the defect, and the localization degree is significantly better than that of a traditional SSH model. Through the synergistic effect of the gradient coupling and the dislocation-induced defect state, efficient localization enhancement of the elastic wave energy is realized, and the application is suitable for the fields of vibration energy collection, high-sensitivity sensing and elastic wave signal processing.

A semiconductor laser device includes a first metamaterial element, a semiconductor substrate having a main surface, and a multijunction active region arranged over the main surface of the semiconductor substrate between the first metamaterial element and the semiconductor substrate. The multijunction active region includes a plurality of active regions each comprising a multiple-quantum-well (MQWs), and a plurality of tunnel junction layers providing electrical coupling and located between neighboring active regions along a vertical direction perpendicular to the main surface of the semiconductor substrate.

The invention provides a laser-electric coupling Taylor cone bionic electrospinning process method, a folded conductive metamaterial and application, the preparation method comprises the following steps: dissolving a carbon nanotube in N, N-dimethylformamide, stirring and carrying out ultrasonic treatment, then adding polymer powder, and continuously stirring to obtain a precursor solution; in the first stage, electrostatic spinning is carried out, meanwhile, a laser beam with the wavelength of 589-650 nm is focused on a rotating Taylor cone for electrostatic spinning, the treated spinning film is heated in air, heat preservation is carried out, then the temperature is reduced to the room temperature, and in the first stage, heating is carried out firstly, and then heat preservation is carried out; then raising the temperature in the second stage, keeping the temperature, and finally cooling to room temperature; in the coupled field spinning process, the synergistic effect of arrangement of the carbon nanotubes and the carbon nanofibers induced by photo-thermal response, local fluidity enhancement and an electric field jointly promotes axial dispersion and slidable in the fibers and formation of a self-adaptive network; and the folded conductive metamaterial capable of being folded for 10 million times is successfully prepared.

The application discloses a novel light-weight pressure-resistant multifunctional metamaterial pipeline silencer system, which comprises an expansion section, a base section and a transition section; the two ends of the expansion section are connected with the base section through the transition section, and the inner diameter of the expansion section is larger than the outer diameter of the base section; the expansion section comprises at least one annular metamaterial base ring, the metamaterial base ring comprises a plurality of anisotropic super-structure shell units connected in sequence along the ring direction, and each anisotropic super-structure shell unit comprises a rigid support framework and a flexible support material; the rigid support framework is provided with holes, and the flexible support material is filled in the holes of the rigid support framework and between two adjacent rigid support frameworks. The application relates to the field of pipeline noise control and can effectively solve the problem of how to realize the integrated design of a pipeline system low-frequency broadband silencer system under the conditions of high pressure resistance and small size, thereby providing a solution with good application prospect for the design of pipeline systems widely used in the fields of aviation and navigation engineering and mechanical engineering.

This invention relates to the field of novel materials, specifically a novel metamaterial exhibiting both multi-stable state and negative Poisson's ratio properties. It comprises a concave hexagonal frame, two arc-shaped beams positioned on the upper and lower sides of the frame's inner cavity, and a vertical rod. The two arc-shaped beams are fixedly connected to the upper and lower ends of the vertical rod via their respective central portions. When the structure is subjected to a vertical compressive load, the frame's diagonal bracing rotates inward, contracting and compressing the ends of the arc-shaped beams, generating a significant negative Poisson's ratio effect. This process forces the arc-shaped beams to bend and deform towards the center, accompanied by energy dissipation. When the displacement reaches a critical threshold, the arc-shaped beams buckle and overturn, switching to a steady state. This invention, through specific geometric configurations and differentiated material layouts, achieves morphological self-repair after impact and reuse under low-intensity conditions. This metamaterial can be arranged as a two-dimensional periodic array as a unit cell.

The invention discloses a two-dimensional five-mode metamaterial with compression resistance and low-frequency sound wave characteristics. The metamaterial is of a hexagonal honeycomb structure formed by periodically arranging a plurality of same two-dimensional unit cell structures. Each unit cell structure is of a hexagonal structure formed by connecting six single-cone unit cells end to end. In view of point contact of a double-cone unit corresponding to a traditional five-mode metamaterial, integral connection is adopted for replacement, so that the stability of the structure is effectively improved, and the five-mode metamaterial with more excellent five-mode characteristics, lower frequency and a complete phonon forbidden band can be designed through fine adjustment of parameters. The method has potential application value in the fields of underwater sound wave low-frequency broadband regulation and control, sound stealth, vibration and noise reduction, earthquake protection and the like.