A fully flexible self-reinforced piezoelectric thin film acoustic metamaterial

Abstract

The application relates to the field of thin film acoustic metamaterials, and provides a full-flexible self-reinforced piezoelectric thin film acoustic metamaterial, which comprises a flexible hollow support frame, a plurality of unfolding and folding mechanisms arranged in the flexible hollow support frame, a first flexible film layer and a second flexible film layer arranged on two surfaces of the flexible hollow support frame respectively, and flexible mass blocks arranged on the outer surface of the second flexible film layer; the unfolding and folding mechanism is composed of a first diaphragm, a second diaphragm, a first flexible pull rope and a second flexible pull rope; the first diaphragm and the second diaphragm are in a shuttle shape in an unforced state; the first diaphragm and the second diaphragm are fixedly connected with the flexible hollow support frame through one side edge of the shuttle shape; the first diaphragm and the second diaphragm are curved into an arc shape in a forced state; and the arc surface of the first diaphragm is opposite to the arc surface of the second diaphragm. The front surface of the diaphragm is pulled by the pull rope, so that the diaphragm and the hollow support frame are flattened, and the effect that the film rod is integrated and can be unfolded and folded for multiple times is achieved.

Description

Technical Field

[0001] This application relates to the field of flexible acoustic metamaterials technology, and more specifically, to a fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial. Background Technology

[0002] Currently, most common piezoelectric thin-film acoustic metamaterials employ rigid frame support, with the added mass blocks typically made of hard materials such as metal. These structures are generally rigid, unable to bend or roll, difficult to conform to curved surfaces, and inconvenient to fold and store, posing inconveniences in transportation and installation. Furthermore, to ensure performance, the film usually needs to be pre-stressed and fixed in shape. Once the prestress is set, the structure is not adjustable, and during transportation or handling, vibration or impact can easily cause the film to loosen or even break, affecting its performance and lifespan.

[0003] Furthermore, most existing structures lack frequency adjustment capabilities. Changing their operating frequency band often requires external devices, such as magnets to adjust the position of the mass block or mechanical structures to re-tighten the thin film. This not only increases the complexity of the system but also reduces reliability and practicality. In addition, the thin film itself has low strength and is prone to aging or damage when subjected to impact or prolonged exposure to harsh environments (such as humidity or underwater), limiting its application in practical engineering.

[0004] Therefore, existing technologies still need improvement. Utility Model Content

[0005] The purpose of this application is to provide a fully flexible, self-reinforcing piezoelectric thin-film acoustic metamaterial to solve the problem that existing piezoelectric thin-film acoustic metamaterials cannot be rolled up and folded.

[0006] To achieve the above objectives, the technical solution adopted in the embodiments of this application is as follows: A fully flexible, self-reinforcing piezoelectric thin-film acoustic metamaterial, comprising: A flexible hollow support frame, wherein several unfolding and retracting mechanisms are provided inside the flexible hollow support frame; A first flexible film layer and a second flexible film layer are respectively disposed on both sides of the flexible hollow support frame, and a flexible mass block is disposed on the outer surface of the second flexible film layer; The unfolding and retracting mechanism consists of a first diaphragm, a second diaphragm, a first flexible pull rope, and a second flexible pull rope; the first flexible pull rope passes through the first diaphragm and is connected to the first diaphragm, and the second flexible pull rope passes through the second diaphragm and is connected to the second diaphragm; both ends of the first flexible pull rope and the second flexible pull rope are exposed on both sides of the flexible hollow support frame; When the first diaphragm and the second diaphragm are in a spindle shape without being subjected to force, the first diaphragm and the second diaphragm are respectively fixedly connected to the flexible hollow support frame through one side of the spindle shape; When the first diaphragm and the second diaphragm are bent into an arc shape under stress, the arc-shaped surface of the first diaphragm is opposite to the arc-shaped surface of the second diaphragm.

[0007] The following are preferred technical solutions of this utility model, but are not intended to limit the technical solutions provided by this invention. Through the following preferred technical solutions, the purpose and beneficial effects of this invention can be better achieved and realized.

[0008] As a preferred technical solution, the fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial includes a square flexible hollow support frame with four flexible hollow components arranged in a grid pattern inside the square frame; the unfolding and retracting mechanism is evenly distributed inside the flexible hollow components.

[0009] As a preferred technical solution, the fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial comprises nine flexible mass blocks, which are distributed in nine square areas divided by the four flexible hollow members arranged in a grid pattern.

[0010] As a preferred technical solution, the fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial further includes an expansion joint for splicing multiple fully flexible self-reinforcing piezoelectric thin film acoustic metamaterials together.

[0011] As a preferred technical solution, the fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial includes an expansion joint comprising: a first expansion joint and a second expansion joint; the first expansion joint is used to splice two adjacent pieces of the fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial together; and the second expansion joint is used to splice four adjacent pieces of the fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial together.

[0012] As a preferred technical solution, the fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial, wherein the first expansion joint includes: a concave base, two concave clips arranged back to back, and the two concave clips arranged back to back are fixed inside the concave base.

[0013] As a preferred technical solution, the fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial wherein the second expansion joint is composed of two first expansion joints.

[0014] As a preferred technical solution, in the fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial, the second expansion joint is formed by two first expansion joints connected back-to-back by snap-fit.

[0015] As a preferred technical solution, the fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial, wherein the flexible hollow support frame is a polyethylene terephthalate-1,4-cyclohexanediol ester hollow support frame.

[0016] The beneficial effects of the fully flexible self-hardening piezoelectric thin-film acoustic metamaterial provided in this application include at least the following: This application employs a flexible hollow support frame with an unfolding and retracting mechanism within it. Initially, (without stress on the diaphragm), the hollow support frame and diaphragm are flattened. Pulling a rope on the diaphragm unfolds the circular tube and diaphragm, supporting the unfolding of the upper and lower membrane layers. Pulling the front of the diaphragm with the rope flattens it and the hollow support frame, achieving an integrated membrane rod that can be repeatedly unfolded and retracted. The diaphragm in this application serves as both a support frame structure and a mass scattering element; its mass and quantity can be adjusted to regulate low-frequency noise reduction performance. It also provides rigid support to the support rod. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A three-dimensional view of a fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial provided for an embodiment of this application.

[0019] Figure 2 An exploded view of a fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial provided in an embodiment of this application.

[0020] Figure 3 This is a schematic diagram of the unfolding and retracting mechanism provided in an embodiment of this application.

[0021] Figure 4 A schematic diagram (bent state) of a diaphragm structure of a fully flexible self-reinforcing piezoelectric thin-film acoustic metamaterial provided in an embodiment of this application.

[0022] Figure 5 This is a schematic diagram of the first expansion joint structure.

[0023] Figure 6This is a schematic diagram of the second expansion joint structure.

[0024] Figure 7 A stereoscopic view of the expanded, fully flexible, self-reinforcing piezoelectric thin-film acoustic metamaterial. Detailed Implementation

[0025] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0026] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it may be directly or indirectly located on that other component. When a component is referred to as "connected to" another component, it may be directly or indirectly connected to that other component. The terms "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate orientations or positions based on the accompanying drawings, and are for ease of description only, and should not be construed as limiting the technical solution. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. "A plurality" means two or more, unless otherwise explicitly defined.

[0027] Please see Figure 1 and Figure 2This application provides a fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial, comprising: a flexible hollow support frame 100, a first flexible thin film layer 110 and a second flexible thin film layer 120 respectively disposed on both sides of the flexible hollow support frame 100, a flexible mass block (such as a flexible piezoelectric fiber block / sheet) 130 disposed on the outer surface of the second flexible thin film layer 120, and a plurality of unfolding and retracting mechanisms 140 disposed inside the flexible hollow support frame 100; wherein, the unfolding and retracting mechanism is composed of a first diaphragm 141, a second diaphragm 142, a first flexible pull rope 143 and a second flexible pull rope 144; the first flexible pull rope 143 passes through the first diaphragm 141 and is connected to the first diaphragm 144. The second flexible pull rope 144 passes through the second diaphragm 142 and is connected to the second diaphragm; both ends of the first flexible pull rope 143 and the second flexible pull rope 144 are exposed on both sides of the flexible hollow support frame 100; when the first diaphragm 141 and the second diaphragm 142 are not under stress, they are in a spindle shape; the first diaphragm 141 and the second diaphragm 142 are respectively fixedly connected to the flexible hollow support frame through one side of the spindle shape; when the pull rope is pulled, the first diaphragm 141 and the second diaphragm 142 are under stress and bent into an arc shape; the arc-shaped surface of the first diaphragm 141 after bending is opposite to the arc-shaped surface of the second diaphragm 142.

[0028] In this embodiment, the tubing constituting the flexible hollow support frame 100 can be a flexible polyethylene terephthalate-1,4-cyclohexanediol (PETG) hollow circular tube, or a tube with a non-circular cross-section. Because it is flexible, it can be folded (flattened / bent). The hollow structure can house internal diaphragms and is easily flattened and deformed. The internal diaphragms can be PETG diaphragms, with two PETG diaphragms forming a set for use. The two PETG diaphragms are identical in shape and material, although one can be different from the other. Setting them identical allows for general use and facilitates management.

[0029] In their initial state (flattened without external force), the two PETG diaphragms are spindle-shaped. The flexible hollow support frame, unsupported by the diaphragms, can be flattened by pressing. At this point, the entire fully flexible, self-reinforcing piezoelectric thin-film acoustic metamaterial can be rolled up. When the pull cord on the diaphragm is pulled, the diaphragm bends into an arc shape (e.g., ...). Figure 3 and Figure 4As shown in the diagram, the flexible hollow support frame unfolds. The diaphragm acts as both a support frame structure and a mass scattering element. By changing the mass and number of diaphragms, the low-frequency noise reduction performance can be adjusted, and it can also provide rigid support for the support rod. The diaphragm can be fixed inside the flexible hollow support frame by adhesive.

[0030] In this embodiment, the flexible hollow support frame 100 is square, which can be either a square or a rectangle; for illustrative purposes, a rectangle is used as an example. The four sides of this rectangle are formed by four flexible hollow tubes connected end-to-end. Inside the rectangular frame, two horizontal and two vertical flexible hollow tubes are arranged, dividing the rectangular frame into nine regions of equal or identical area. These regions are used to house flexible mass blocks. Flexible films, namely the first flexible film layer 110 and the second flexible film layer 120, are laid on both sides of the rectangular frame. Inside the square frame, four flexible hollow members are arranged in a grid pattern; the unfolding and retracting mechanism is evenly distributed within each flexible hollow member.

[0031] In this embodiment, the fully flexible self-hardening piezoelectric thin-film acoustic metamaterial can be considered as a unit module. Multiple unit modules can be connected and combined using expansion joints, such as the first expansion joint 200 used to combine two unit modules together. Figure 5 As shown, the second expansion connector 300 is used to combine the four unit modules together, as follows: Figure 6 As shown, the structure of the four unit modules combined together is as follows: Figure 7 As shown.

[0032] In this embodiment, the first expansion connector 200 includes: a concave base 201 and two concave clips 202 arranged back to back, wherein the two concave clips arranged back to back are fixed (either by snap-fit, welding or integral molding) within the concave base 201.

[0033] A snap-fit ​​groove 210 or a snap-fit ​​component adapted to the snap-fit ​​groove can be provided on the back of the concave base 201. When two first expansion connectors are snapped together back to back, they form a second expansion connector 300. Of course, when two first expansion connectors are combined to form a first expansion connector, the connection and fixing method is not limited to snap-fit; other connection and fixing methods can also be used, such as welding, gluing, etc.

[0034] The fully flexible, self-reinforcing piezoelectric thin-film acoustic metamaterial provided in this application possesses functional characteristics such as flexibility, deployability, and self-reinforcing. Through a geometric design of bending creases, it achieves both deployability and self-locking properties, effectively enhancing overall stiffness and maintaining stability after deployment. This fully flexible, self-reinforcing piezoelectric thin-film acoustic metamaterial can be integrated into a flexible acoustic metamaterial system. The deployable structure enables dynamic control of acoustic functions, making the device lightweight, portable, and capable of efficient sound wave control. This invention features high specific stiffness, impact resistance, simple structure, and convenient adjustment. The use of two types of connectors—a first expansion joint and a second expansion joint—allows for modular assembly. Furthermore, when the fully flexible, self-reinforcing piezoelectric thin-film acoustic metamaterial is retracted, it can switch to a bistable mode, softening the membrane before retracting. Integrated membrane-rod retraction is possible, resulting in a high storage ratio, small footprint, and convenient storage and transportation. It also exhibits good low-frequency sound absorption and insulation effects. An external damping circuit connected to the piezoelectric fiber composite material on the film further enhances the low-frequency noise reduction effect of the acoustic metamaterial.

[0035] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A fully flexible, self-reinforcing piezoelectric thin-film acoustic metamaterial, characterized in that, include: A flexible hollow support frame, wherein several unfolding and retracting mechanisms are provided inside the flexible hollow support frame; A first flexible film layer and a second flexible film layer are respectively disposed on both sides of the flexible hollow support frame, and a flexible mass block is disposed on the outer surface of the second flexible film layer; The unfolding and retracting mechanism consists of a first diaphragm, a second diaphragm, a first flexible pull rope, and a second flexible pull rope; the first flexible pull rope passes through the first diaphragm and is connected to the first diaphragm, and the second flexible pull rope passes through the second diaphragm and is connected to the second diaphragm; both ends of the first flexible pull rope and the second flexible pull rope are exposed on both sides of the flexible hollow support frame; When the first diaphragm and the second diaphragm are in a spindle shape without being stressed, the first diaphragm and the second diaphragm are respectively fixedly connected to the flexible hollow support frame through one side of the spindle shape; When the first diaphragm and the second diaphragm are bent into an arc shape under stress, the arc-shaped surface of the first diaphragm is opposite to the arc-shaped surface of the second diaphragm.

2. The fully flexible self-reinforcing piezoelectric thin-film acoustic metamaterial as described in claim 1, characterized in that, The flexible hollow support frame is square, and four flexible hollow components arranged in a grid pattern are set inside the square frame; the unfolding and retracting mechanism is evenly distributed inside the flexible hollow components.

3. The fully flexible self-reinforcing piezoelectric thin-film acoustic metamaterial as described in claim 2, characterized in that, Nine flexible mass blocks are provided, and the nine flexible mass blocks are distributed in nine square areas divided by the four flexible hollow members arranged in a grid pattern.

4. The fully flexible self-reinforcing piezoelectric thin-film acoustic metamaterial as described in claim 1, characterized in that, The fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial also includes an expansion joint, which is used to splice multiple fully flexible self-reinforcing piezoelectric thin film acoustic metamaterials together.

5. The fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial as described in claim 4, characterized in that, The expansion joint includes: a first expansion joint and a second expansion joint; the first expansion joint is used to splice two adjacent pieces of the fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial together; the second expansion joint is used to splice four adjacent pieces of the fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial together.

6. The fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial as described in claim 5, characterized in that, The first expansion connector includes: a concave base and two concave clips arranged back to back, the two concave clips being fixed inside the concave base.

7. The fully flexible self-reinforcing piezoelectric thin-film acoustic metamaterial as described in claim 5, characterized in that, The second expansion connector consists of two of the first expansion connectors.

8. The fully flexible self-reinforcing piezoelectric thin film acoustic metamaterial as described in claim 7, characterized in that, The second expansion connector is formed by two first expansion connectors connected back-to-back via snap-fit.

9. The fully flexible self-reinforcing piezoelectric thin-film acoustic metamaterial as described in any one of claims 1-8, characterized in that, The flexible hollow support frame is a polyethylene terephthalate-1,4-cyclohexanediol ester hollow support frame.

Images