Flexible multifunctional material and preparation method thereof

Abstract

The invention provides a flexible multifunctional material and a preparation method thereof, and relates to the technical field of flexible materials.The flexible multifunctional material comprises a functional layer and a pressure-sensitive layer, the pressure-sensitive layer comprises a plurality of units which are arranged in an array and have the negative Poisson's ratio effect, the top ends of the units are connected with the functional layer, the heights of the transversely-arranged units are the same, and the height of the pressure-sensitive layer is larger than that of the functional layer. The heights of the adjacent units arranged longitudinally are different; the flexible multifunctional material is integrally formed by a flexible material. The flexible multifunctional material provided by the invention has heat-proof, wave-absorbing and excellent coating functions, and can be industrially prepared.

Description

Technical Field

[0001] The invention relates to the technical field of flexible materials, and in particular to a flexible multifunctional material and a preparation method thereof. Background Art

[0002] Negative Poisson's ratio materials and structures have special mechanical properties. They shrink (expand) laterally under uniaxial pressure (tension). They have advantages over traditional materials in terms of shear bearing capacity, fracture resistance, energy absorption and indentation resistance. Therefore, negative Poisson's ratio materials have broad application prospects in medical equipment, flexible sensors, protective equipment, aviation and navigation, and national defense engineering. Compared with flexible materials such as hydrogels and foams, negative Poisson's ratio materials have excellent mechanical properties and impact resistance, and are easy to achieve close fit on non-developable surfaces, that is, better conformability. However, the application and popularization of negative Poisson's ratio materials still face some challenges.

[0003] At present, the main problems faced by negative Poisson's ratio materials are high manufacturing costs and difficulty in industrialization. Except for fabric forms, most negative Poisson's ratio materials need to be manufactured by 3D printing, which has a long manufacturing cycle, high cost and limited size. Although the negative Poisson's ratio structure in fabric form has excellent conformal ability, its function is single and needs to cooperate with other functional materials to achieve functions such as heat protection, electromagnetic and infrared stealth. It may even cause wrinkles and cracks due to the different materials of the fabric and the functional material. Therefore, it is necessary to propose a flexible multifunctional material with both heat protection, wave absorption and excellent conformal properties and a preparation method thereof. Summary of the invention

[0004] The embodiment of the present invention provides a flexible multifunctional material and a preparation method thereof. The provided flexible multifunctional material has heat protection, wave absorption and excellent conformal functions, and can be prepared industrially.

[0005] In the first aspect, the present invention provides a flexible multifunctional material, comprising a functional layer and a pressure-sensitive layer, wherein the pressure-sensitive layer comprises a plurality of units having a negative Poisson's ratio effect arranged in an array, the top ends of the units are connected to the functional layer, the heights of the units arranged laterally are the same, and the heights of adjacent units arranged vertically are different; the flexible multifunctional material is obtained by integrally molding a flexible material.

[0006] Preferably, the structure of the unit includes a concave angle structure, a chiral structure, and a rotational rigid body structure.

[0007] Preferably, the ratio of the height of the functional layer to the height of the pressure-sensitive layer is (0.5-5):(0.3-10).

[0008] Preferably, the pressure-sensitive layer comprises a first unit and a second unit arranged in an array; wherein the height of the first unit is higher than the height of the second unit; and the height of the pressure-sensitive layer is the same as the height of the first unit;

[0009] In the longitudinal arrangement direction, the first unit is adjacent to the second unit.

[0010] Preferably, in the transverse arrangement direction, the ratio of the spacing between adjacent units to the width of the first unit is (0.1-1):1.

[0011] Preferably, the ratio of the length of the second unit to the height of the first unit is (1-300):1.

[0012] Preferably, the ratio of the height of the first unit to the height of the second unit is 1:(0.5-0.8).

[0013] Preferably, a feeler is further provided at the bottom end of the first unit, and the feeler is at least one of an L-shape, a ⊥-shape, and a ┛-shape.

[0014] Preferably, the flexible material is at least one of silicone rubber, natural rubber, polyurethane, and polyacrylate elastomer.

[0015] In a second aspect, the present invention provides a method for preparing the flexible multifunctional material according to the first aspect, the method comprising:

[0016] Extruding a flexible material through a template of a screw extruder to obtain a preformed material; wherein the cross section of the template is designed with a plurality of continuously arranged units having a negative Poisson's ratio effect; the preformed material comprises a functional layer and a plurality of rows of negative Poisson's ratio layers comprising a plurality of continuously arranged units;

[0017] After the negative Poisson's ratio layer of the preformed material is cut along the extrusion direction, the negative Poisson's ratio layer includes a plurality of units arranged in an array, thereby obtaining the flexible multifunctional material; wherein the heights of adjacent units arranged along the extrusion direction are different, and the heights of adjacent units arranged perpendicular to the extrusion direction are the same.

[0018] Preferably, the flexible material is silicone rubber; the silicone rubber comprises the following components in parts by weight: 100 parts of raw rubber, 35-40 parts of white carbon black, 1.5 parts of zinc stearate, 5-8 parts of structure control agent, 1-2 parts of vinyl silicone oil, 1 part of vulcanizing agent, and 0.5 part of auxiliary agent.

[0019] Preferably, the bottom end of the unit having the same height as the unit on the template is cut so that the unit has antennae.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] The flexible multifunctional material provided by the present invention includes a functional layer and a pressure-sensitive layer made of a flexible material in one piece. The pressure-sensitive layer includes a plurality of units with a negative Poisson's ratio effect arranged in an array. The top of the unit is connected to the functional layer. In the lateral arrangement direction of the array, the heights of the units are the same; the heights of adjacent units in the longitudinal arrangement direction are different. In this way, the flexible multifunctional material can achieve a tight fit on a non-expandable curved surface while taking advantage of the excellent mechanical properties and impact resistance of the units, and has excellent conformal properties; at the same time, with the help of units of different heights, the conformal ability of the flexible multifunctional material is further increased. At the same time, the functional layer is connected to the pressure-sensitive layer provided with the units, and is obtained by integral molding, which avoids problems such as wrinkles and cracks caused by different materials, improves the mechanical properties of the flexible multifunctional material, and the functional layer can also achieve functions such as heat protection, wave absorption, and infrared stealth.

[0022] In the present invention, the flexible multifunctional material is prepared in one piece by co-extrusion. On the one hand, it can realize large-area manufacturing of materials with negative Poisson's ratio structure to meet the skin manufacturing of large components and realize industrialized preparation; on the other hand, since the pressure-sensitive layer and the functional layer are integrated, the introduction of functional layers such as wave absorption, stealth or heat protection will not be affected by the conformal performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 is a schematic cross-sectional structure diagram of a flexible multifunctional material provided by one embodiment of the present invention;

[0025] Figure 2 yes Figure 1 A schematic diagram of a planar structure of a flexible multifunctional material is shown;

[0026] Figure 3 is a schematic cross-sectional structure diagram of another flexible multifunctional material provided by one embodiment of the present invention;

[0027] Figure 4 yes Figure 1 A schematic diagram of the planar structure of another flexible multifunctional material is shown;

[0028] Figure 5 is a schematic cross-sectional structure diagram of another flexible multifunctional material provided by an embodiment of the present invention;

[0029] Figure 6 is a schematic cross-sectional structure diagram of another flexible multifunctional material provided by an embodiment of the present invention;

[0030] Reference numerals: 10 - functional layer; 20 - pressure-sensitive layer; 200 - unit; 201 - first unit; 202 - second unit; 2011 - antenna. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] The present invention provides a flexible multifunctional material. Figure 1 and Figure 2 As shown, it includes: a functional layer 10 and a pressure-sensitive layer 20, the pressure-sensitive layer 20 includes a plurality of units 200 with a negative Poisson's ratio effect arranged in an array, the top of the unit 200 is connected to the functional layer 10, the heights of the units 200 arranged horizontally are the same, and the heights of adjacent units 200 arranged vertically are different; the flexible multifunctional material is obtained by integrally molding a flexible material.

[0033] In the present invention, the flexible multifunctional material includes a functional layer and a pressure-sensitive layer made of a flexible material in one piece. The pressure-sensitive layer includes a plurality of units arranged in an array. The top of the unit is connected to the functional layer. In the lateral arrangement direction of the array, the heights of the units are the same; the heights of adjacent units in the longitudinal arrangement direction are different. In this way, the flexible multifunctional material can achieve a tight fit on a non-expandable curved surface while taking advantage of the excellent mechanical properties and impact resistance of the unit, and has excellent conformal properties; at the same time, with the help of units of different heights, the conformal ability of the flexible multifunctional material is further increased. At the same time, the functional layer is connected to the pressure-sensitive layer provided with the unit, and is obtained by integral molding, which avoids problems such as wrinkles and cracks caused by different materials, improves the mechanical properties of the flexible multifunctional material, and the functional layer can also achieve functions such as heat protection, wave absorption, and infrared stealth.

[0034] It should be noted that the horizontal and vertical directions do not constitute specific limitations for the flexible multifunctional material, but are only used to distinguish the arrangement directions. In a specific embodiment, the heights of the units arranged in the vertical direction may be the same, and the heights of adjacent units arranged in the horizontal direction may be different. The unit having a negative Poisson's ratio effect may be a unit including a negative Poisson's ratio structure, or a unit including a quasi-negative Poisson's ratio structure.

[0035] Specifically, in actual application scenarios, the tentacles of the flexible multifunctional material fit the complex curved surface of the device to be bonded. Since the bottom is a negative Poisson's ratio material, the conformation process can sensitively sense the changes in the conformation surface and form its own deformation. After the bonding is completed, the characteristics of the internal surface are basically consistent with the characteristics of the external functional layer, and the functional layer is a flat layer, so the functional layer will not change the contour and curvature of the device to be bonded after the conformation, and the surface of the functional layer is flat and wrinkle-free after bonding. At the same time, the flexible multifunctional material can be bonded to the surface of the device to be bonded with variable curvature by stretching or compressing, that is, it has a negative Poisson's ratio bonding effect in both the stretching direction and the compression direction.

[0036] According to some more preferred embodiments, the plurality of units 200 in the pressure-sensitive layer 20 are arranged in a gradient manner.

[0037] Specifically, for devices with complex curved surfaces to be bonded, the curvatures of the surfaces at different locations are different. Therefore, the density of the units at different curvatures (i.e., the spacing between adjacent units) is flexibly designed to arrange them in a gradient pattern (e.g., Figure 1 As shown in the figure, the flexible multifunctional material can adapt itself as the curvature of the built surface changes, and can give full play to the performance of the negative Poisson's ratio structure in the pressure-sensitive layer.

[0038] According to some preferred embodiments, the structure of the unit includes a concave angle structure, a chiral structure, and a rotational rigid body structure.

[0039] Specifically, the structure of the unit is preferably a honeycomb unit with negative Poisson's quotient characteristics.

[0040] According to some preferred embodiments, the ratio of the height of the functional layer to the pressure-sensitive layer is (0.5-5):

[0041] (0.3 to 10) (for example, it can be 0.5:0.3, 1:1, 0.5:2, 0.5:5, 0.5:10, 1:0.3, 1:2, 1:5, 1:10, 2:0.3, 2:1, 2:5, 2:15, 5:0.3, 5:1 or 5:9).

[0042] Specifically, the thickness of the functional layer and the pressure-sensitive layer can be designed according to actual service conditions.

[0043] According to some more preferred embodiments, the ratio of the height of the functional layer to the pressure-sensitive layer is 1:(0.3-10) (for example, it can be 1:0.3, 1:0.5, 1:0.8, 1:1, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10).

[0044] In an embodiment of the present invention, the height ratio of the functional layer to the pressure-sensitive layer is set to 1:(0.3-10), which can avoid the functional layer being too thick, resulting in a large equivalent modulus and a low transfer efficiency from the pressure-sensitive layer to the functional layer, and can also further reduce the thickness of the flexible multifunctional composite material.

[0045] According to some preferred embodiments, Figure 3 and Figure 4 As shown, the pressure-sensitive layer 20 includes a first unit 201 and a second unit 202 arranged in an array; wherein the height of the first unit 201 is higher than the height of the second unit 202, and both the first unit 201 and the second unit 202 include a negative Poisson's ratio structure; the height of the pressure-sensitive layer 20 is the same as the height of the first unit 201;

[0046] In the longitudinal arrangement direction, the first unit 201 is adjacent to the second unit 202 .

[0047] In the embodiment of the present invention, in the longitudinal arrangement direction, the first unit and the second unit with different heights are adjacent to each other, so that the unit can exert its excellent conformal performance on the complex curved surface.

[0048] According to some preferred embodiments, both the first unit and the second unit are complete negative Poisson's ratio structural units.

[0049] In an embodiment of the present invention, the units of the pressure-sensitive layer are all complete negative Poisson's ratio structural units. In this way, each unit is a complete negative Poisson's ratio structural unit, and each negative Poisson's ratio structural unit can fully play its role, so that the flexible multifunctional material has a negative Poisson's ratio fitting effect in both the tensile direction and the compression direction.

[0050] According to some preferred embodiments, Figure 4 As shown, in the lateral arrangement direction, the spacing D between adjacent units 1 The width D of the first unit 2 The ratio is (0.1-1):1 (for example, it can be 0.1:1, 0.15:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1 or 1:1).

[0051] In the embodiment of the present invention, in order to make the flexible multifunctional material more conformable to the curved device surface, the ratio of the spacing between adjacent units to the width of the first unit is limited to (0.1-1):1, so that the unit with negative Poisson's ratio effect can exert its excellent conformal performance at any curvature; if the spacing is too large, the conformal performance of the flexible multifunctional material will be reduced, and even the mechanical properties of the flexible multifunctional material will be affected. It should be noted that the width of the first unit is the spacing of the widest part of the negative Poisson's ratio structure corresponding to the first unit.

[0052] According to some preferred embodiments, Figure 3 and Figure 4 As shown, the length L of the second unit is equal to the height H of the first unit. 1 The ratio is (1-300):1 (for example, it can be 1:1, 2:1, 5:1, 10:1, 15:1, 20:1, 30:1, 50:1, 100:1, 120:1, 150:1, 200:1, 250:1, 280:1 or 300:1).

[0053] It should be noted that the ratio of the length of the second unit to the height of the first unit is specifically designed according to actual service conditions.

[0054] According to some preferred embodiments, Figure 3 As shown, the height H of the first unit 1 The height H of the second unit 2 The ratio is 1:(0.5-0.8) (for example, it can be 1:0.5, 1:0.55, 1:0.6, 1:0.65, 1:0.7, 1:0.75 or 1:0.8).

[0055] In an embodiment of the present invention, the ratio of the height of the first unit to the height of the second unit is limited to 1:(0.5-0.8), which not only avoids the problem of poor flexibility and conformability of the flexible multifunctional material when the height difference between the two is too low, but also avoids the problem of poor mechanical properties of the flexible multifunctional material when the height difference between the two is too high.

[0056] According to some preferred embodiments, a feeler is further provided at the bottom end of the first unit, and the feeler is at least one of an L-shape, a ⊥-shape, and a ┛-shape.

[0057] In the embodiment of the present invention, the bottom of the first unit is in direct contact with the device to be bonded, and the feeler is arranged at the bottom of the first unit, which can further increase the contact area with the device to be bonded, so that the two are bonded more firmly.

[0058] According to some preferred embodiments, the flexible material is at least one of silicone rubber, natural rubber, polyurethane, and polyacrylate elastomer.

[0059] It should be noted that at least one is any one or a mixture of any several in any proportion. The flexible material is preferably a material that is resistant to high temperatures above 200°C.

[0060] The present invention also provides a method for preparing the above-mentioned flexible multifunctional material, the preparation method comprising:

[0061] Extruding a flexible material through a template of a screw extruder to obtain a preformed material; wherein the cross section of the template is designed with a plurality of continuously arranged units having a negative Poisson's ratio effect; the preformed material comprises a functional layer and a plurality of rows of negative Poisson's ratio layers comprising a plurality of continuously arranged units;

[0062] After the negative Poisson's ratio layer of the preformed material is cut along the extrusion direction, the negative Poisson's ratio layer includes a plurality of units arranged in an array, thereby obtaining a flexible multifunctional material; wherein the heights of adjacent units arranged along the extrusion direction are different, and the heights of units arranged along the perpendicular extrusion direction are the same.

[0063] It should be noted that the negative Poisson's ratio layer includes N rows, and each row is composed of a plurality of continuously arranged units.

[0064] In the present invention, the flexible multifunctional material is prepared in one piece by co-extrusion. Compared with the material with a negative Poisson's ratio structure prepared by 3D printing, on the one hand, large-area manufacturing of the material with a negative Poisson's ratio structure can be achieved to meet the skin manufacturing of large components, realize industrialized preparation, and reduce manufacturing costs; on the other hand, since the pressure-sensitive layer and the functional layer are integrated, the introduction of functional layers such as wave absorption, stealth or heat protection will not be affected by the conformal performance.

[0065] It should be noted that the heights of the units arranged transversely are the same, which means that the heights of the units arranged along the vertical extrusion direction are the same; the heights of the adjacent units arranged longitudinally are different, which means that the heights of the adjacent units arranged along the extrusion direction or parallel to the extrusion direction are different. The template is installed at the front end of the extrusion head of the screw extruder. When the flexible material passes through the screw extruder and the template, a long strip (rectangular or cube-shaped) product with a negative Poisson's ratio structure is prepared. The template is an extrusion mold or a die, and is a metal template made of stainless steel, aluminum alloy or titanium alloy. The cross-section of the metal template can be determined according to specific requirements and the use requirements of the material product.

[0066] More specifically, if Figure 3 As shown, after the negative Poisson's ratio layer of the preformed material is orderly cut along the extrusion direction, a first unit having the same height as the negative Poisson's ratio layer and a second unit having a lower height than the first unit are obtained, and in the direction parallel to the extrusion direction, the first unit is adjacent to the second unit, forming a concave-convex orderly contact surface. The unit with the negative Poisson's ratio effect can be a unit containing a negative Poisson's ratio structure or a unit containing a quasi-negative Poisson's ratio structure. The negative Poisson's ratio structure or the quasi-negative Poisson's ratio structure in the unit after cutting may be partially destroyed, but since the unit still contains most of the complete negative Poisson's ratio structure or the quasi-negative Poisson's ratio structure, the first unit and the second unit after cutting still have the negative Poisson's ratio effect.

[0067] It should be noted that the cutting interval can be equal-interval cutting, orderly-interval cutting designed according to a gradient, or specific-interval cutting designed according to the curvature of the surface.

[0068] More specifically, there are two ways to perform equal-interval cutting:

[0069] The first one is that after cutting, the first unit and the second unit are both composed of a number of complete negative Poisson's ratio structural units, that is, the negative Poisson's ratio structures constituting the first unit and the second unit are the same, and only the number of negative Poisson's ratio structural units constituting the first unit is different from the number of negative Poisson's ratio structural units constituting the second unit; in this case, the spacing during cutting is an integer multiple of the width of the negative Poisson's ratio structural unit, and the depth during cutting is an integer multiple of the height of the negative Poisson's ratio structural unit.

[0070] The second type is that the first unit and the second unit after cutting are both composed of several complete negative Poisson's ratio structural units, but the negative Poisson's ratio structural units that constitute the first unit are different from the negative Poisson's ratio structural units that constitute the second unit; in this case, the spacing and depth during cutting are determined by the negative Poisson's ratio structural units that constitute the second unit. Figure 5 As shown, the negative Poisson's ratio structural elements of the first unit and the second unit are different.

[0071] According to some preferred embodiments, the flexible material is silicone rubber; the silicone rubber includes the following components in parts by weight: 100 parts of raw rubber, 35-40 parts of white carbon black, 1.5 parts of zinc stearate, 5-8 parts of structure control agent, 1-2 parts of vinyl silicone oil, 1 part of vulcanizing agent, and 0.5 part of auxiliary agent.

[0072] According to some preferred embodiments, the bottom end of the unit having the same height as the unit on the template is cut so that the unit has antennae.

[0073] More specifically, if Figure 6 As shown, cutting is performed at the bottom of the first unit at the same height as the pressure-sensitive layer to obtain an L-shaped, ⊥-shaped or ┛-shaped antenna 2011. The cutting size of the antenna is designed according to specific application requirements.

[0074] It should be noted that the functional layer is designed to have certain functions such as wave absorption, sweating and infrared stealth according to application requirements.

[0075] In order to more clearly illustrate the technical solution and advantages of the present invention, a method for preparing a flexible multifunctional material is described in detail below through an embodiment.

[0076] Example

[0077] (1) The following components in parts by weight are mixed to obtain a rubber mixture: 100 parts of raw rubber, 40 parts of white carbon black, 1.5 parts of zinc stearate, 5 parts of a structure control agent (dimethylhydroxy silicone oil), 2 parts of vinyl silicone oil, 1 part of a vulcanizing agent (2,4-dichlorobenzoyl peroxide), and 0.5 parts of an auxiliary agent (iron oxide);

[0078] (2) The rubber compound is extruded through a pre-designed template using a twin-screw extruder at an extrusion temperature of 50°C, and then the extruded material is subjected to hot air vulcanization (temperature of 380°C, vulcanization time of 30s), and a preformed material is obtained after cooling to room temperature; wherein the preformed material includes a functional layer and a plurality of rows of negative Poisson's ratio layers composed of a plurality of continuously arranged units, and the extrusion direction is the Y direction (i.e. Figure 4 longitudinal direction in the ;

[0079] (3) The continuously arranged units are cut at equal intervals along the YZ direction by mechanical cutting, so that the negative Poisson's ratio layer is an array of the first unit 201 and the second unit 202 arranged in an orderly manner, and the following is obtained: Figure 3 and Figure 4 The flexible multifunctional material shown includes an integrally formed functional layer 10 and a pressure-sensitive layer 20 arranged in an array.

[0080] It should be noted that Figure 4 The plane shown in the figure is the XY plane, in which the transverse direction is the X direction and the longitudinal direction is the Y direction; in the transverse arrangement direction, the spacing D between adjacent units 1 Set by the extrusion process.

[0081] The drawings of the present invention are provided for illustrative purposes only, and the proportions, sizes and quantities of the various parts in the drawings may not necessarily be consistent with the actual products.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flexible multifunctional material, characterized in that: The flexible multifunctional material includes a functional layer and a pressure-sensitive layer. The pressure-sensitive layer includes a plurality of units with a negative Poisson's ratio effect arranged in an array. The tops of the units are connected to the functional layer. The heights of the units arranged horizontally are the same, and the heights of adjacent units arranged vertically are different. The flexible multifunctional material is obtained by integrally molding a flexible material.

2. The flexible multifunctional material according to claim 1, characterized in that: The structure of the unit includes a concave angle structure, a chiral structure, and a rotational rigid body structure; and / or, The height ratio of the functional layer to the pressure-sensitive layer is (0.5-5):(0.3-10).

3. The flexible multifunctional material according to claim 1, characterized in that: The pressure-sensitive layer comprises a first unit and a second unit arranged in an array; wherein the height of the first unit is higher than the height of the second unit; and the height of the pressure-sensitive layer is the same as the height of the first unit; In the longitudinal arrangement direction, the first unit is adjacent to the second unit.

4. The flexible multifunctional material according to claim 3, characterized in that: In the transverse arrangement direction, the ratio of the spacing between adjacent units to the width of the first unit is (0.1-1):

1.

5. The flexible multifunctional material according to claim 3, characterized in that: The ratio of the length of the second unit to the height of the first unit is (1-300):

1.

6. The flexible multifunctional material according to claim 3, characterized in that: The ratio of the height of the first unit to the height of the second unit is 1:(0.5-0.8).

7. The flexible multifunctional material according to claim 3, characterized in that: The bottom end of the first unit is also provided with a feeler, and the feeler is at least one of an L-shape, a ⊥-shape, and a ┛-shape.

8. The flexible multifunctional material according to any one of claims 1 to 7, characterized in that: The flexible material is at least one of silicone rubber, natural rubber, polyurethane and polyacrylate elastomer.

9. A method for preparing the flexible multifunctional material according to any one of claims 1 to 8, characterized in that: The preparation method comprises: Extruding a flexible material through a template of a screw extruder to obtain a preformed material; wherein the cross section of the template is designed with a plurality of continuously arranged units having a negative Poisson's ratio effect; the preformed material comprises a functional layer and a plurality of rows of negative Poisson's ratio layers comprising a plurality of continuously arranged units; After the negative Poisson's ratio layer of the preformed material is cut along the extrusion direction, the negative Poisson's ratio layer includes a plurality of units arranged in an array, thereby obtaining the flexible multifunctional material; wherein the heights of adjacent units arranged along the extrusion direction are different, and the heights of adjacent units arranged perpendicular to the extrusion direction are the same.

10. The preparation method according to claim 9, characterized in that: The flexible material is silicone rubber; the silicone rubber comprises the following components in parts by weight: 100 parts of raw rubber, 35-40 parts of white carbon black, 1.5 parts of zinc stearate, 5-8 parts of structure control agent, 1-2 parts of vinyl silicone oil, 1 part of vulcanizing agent, and 0.5 parts of auxiliary agent; and / or, The bottom end of the unit is cut at the same height as the unit on the template so that the unit has antennae.

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