A camouflage stealth skin based on structural color and its preparation method

Abstract

The present invention discloses a camouflage stealth skin based on structural color, comprising a base layer, a first reflective layer, an intermediate dielectric layer, a second reflective layer and a top protective layer arranged in sequence from bottom to top, wherein the material of the first reflective layer is selected from one of Al, Ag or Au. The present invention also provides a preparation method of the camouflage stealth skin based on structural color. Compared with the prior art, the camouflage stealth skin based on structural color prepared by the present invention has stable performance, radiation resistance, long service life, strong color customization capability, and can be customized in a variety of colors. At the same time, the raw materials for preparing the camouflage skin of the present invention are easily available, and the preparation method is simple, which not only can realize batch preparation, but also is green, environmentally friendly and pollution-free.

Description

Technical Field

[0001] The present invention belongs to the field of stealth technology, and in particular relates to a camouflage stealth skin based on structural color and a preparation method thereof. Background Art

[0002] Camouflage is a common camouflage method, primarily used in military and hunting settings. Its primary function is to act as an artificial protective coloration, reducing visibility and preventing detection by enemies or prey, which could lead to a loss of advantage or endangerment. A camouflage pattern is composed of two elements: pattern / color shape (lines) and color (color matching). Patterns (color blocks) disrupt the outline of an object, while colors blend into the background, reducing recognition (protective coloration). All camouflage patterns are derived from a combination of these two elements. Currently, common camouflage clothing is made from synthetic fibers. By adding special chemicals to the color dyes, the clothing's infrared reflectivity is roughly similar to that of the surrounding landscape, thus achieving a certain degree of camouflage effectiveness. However, these stealth coatings made with pigments and other chemical dyes can fade under long-term exposure to light, resulting in poor durability. This is because chemical colors are formed when chemical components on the surface of an object absorb specific wavelengths of light. The stability of this color depends on the stability of its chemical components. For example, dyes and photographs fade over time, and lignin in wood decomposes and fades over time in sunlight. These are all caused by the decomposition of chemical colors. In contrast, there is physical color, also known as structural color. This refers to the color produced by the refraction, diffuse reflection, diffraction, or interference of light caused by the ordered microscopic structure of an object's surface. The colorful textures on the surfaces of CDs, some butterflies, beetles, and soap bubbles are all examples of structural color. By manipulating the microscopic structure of a material's surface, it is possible to create a variety of colors that are completely different from its original color.

[0003] Compared to common chemical pigments, the color-rendering mechanism of structural colors gives them unique and remarkable properties, primarily manifested in the following aspects: 1. Rich colors. Structural colors can select specific wavelengths by controlling their material properties and surface structure. Countless structural color combinations can be created using different materials and structural configurations, allowing for customized color. 2. Controllable colors. Unlike pigment colors, which are fixed upon application, the micro-nanostructures in structural colors undergo deformation under external stimuli such as light, electricity, force, magnetism, and heat, allowing for the manipulation of light waves. Furthermore, some structural colors are polarization-sensitive and sensitive to the angle of incident light. By manipulating the polarization state or angle of incident light, color can be adjusted and controlled. 3. Stable physical and chemical properties. While pigment colors can fade under prolonged sunlight, the structural characteristics of structural colors make them corrosion-resistant and radiation-resistant, making them suitable for even harsher environments. 4. Environmentally friendly and pollution-free. Some chemical pigments have pungent odors, are extremely harmful to the environment and the human body, and may even contain carcinogens. The physical properties of structural colors determine their clean and pollution-free nature, and their production is typically achieved using physical methods such as electron beam evaporation and magnetron sputtering, rather than traditional printing methods like dye vats and inkjet printing.

[0004] Multiple reports indicate that currently common visible light stealth skins often use dye coatings to create camouflage colors, achieving stealth through camouflage patterns that mimic natural colors. However, these patterns suffer from poor durability and radiation resistance, and fade under prolonged sunlight. Therefore, designing durable camouflage stealth skins has become a pressing issue. Summary of the Invention

[0005] The purpose of the present invention is to provide a camouflage stealth skin based on structural color that has a large field of view, a wide color gamut, good flexibility and is easy to prepare in large-scale batches.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a camouflage stealth skin based on structural color, comprising a base layer, a first reflective layer, an intermediate dielectric layer, a second reflective layer and a top protective layer arranged in sequence from bottom to top, and the material of the first reflective layer is selected from one of Al, Ag or Au.

[0007] The present invention is based on the Fabry-Perot (FP) resonance mechanism and designs an FP-type multilayer film structural color. It is insensitive to the angle of incident light and has stable physical and chemical properties. Multi-color customization can be achieved by changing the film layer configuration.

[0008] Preferably, the material of the base layer is aluminum foil or PET film.

[0009] Preferably, the intermediate dielectric layer is made of silicon or germanium. The thickness of the intermediate dielectric layer 3 determines the location of the trough, i.e., the color hue. Furthermore, the use of the aforementioned high-refractive-index material for the intermediate dielectric layer 3 of the present invention allows for a thinner film configuration. This ultra-thin structure ensures that the color and spectral performance of the asymmetric, ultra-thin structural color remain virtually unchanged over a wide field of view.

[0010] Preferably, the material of the second reflective layer is selected from one of Al, Ag or Au. The material of the second reflective layer of the present invention can be a metal material with low absorption and high reflectivity in the visible light band.

[0011] Preferably, the top protective layer is made of SiO2 or Al2O3. The material of the second reflective layer of the present invention is translucent, allowing incident light to enter the intermediate dielectric layer and generate FP resonance. At the same time, the thickness of the second reflective layer determines the height of the reflection trough, that is, the color brightness.

[0012] Another object of the present invention is to provide a method for preparing a camouflage stealth skin based on structural color, the preparation method specifically comprising the following steps:

[0013] S1. After cleaning and drying the substrate, place it in the vacuum chamber of the electron beam evaporation coating machine, and then pump the vacuum chamber to a vacuum degree of <3.0x10 -3 Pa, and then clean the substrate with an ion source filled with argon;

[0014] S2. Design the film system according to actual needs and determine the coating materials and thickness of each layer;

[0015] S3. A first reflective layer is formed on the substrate obtained in step S1 according to the film system designed in step S2;

[0016] S4 using an electron beam evaporation coating machine to deposit an intermediate dielectric layer on the first reflective layer obtained in step S3;

[0017] S5. Depositing a second reflective layer on the intermediate dielectric layer obtained in step S4 using an electron beam evaporation coating machine;

[0018] S6. Using an electron beam evaporation coating machine, evaporate a top protective layer on the second reflective layer obtained in step S5 to obtain a camouflage stealth skin based on structural color.

[0019] Preferably, in step S3, the film forming rate is ≤0.3 nm / s.

[0020] Preferably, in step S4, the film forming rate is ≤0.2 nm / s.

[0021] Preferably, in step S5, the film forming rate is ≤0.2 nm / s.

[0022] Preferably, in step S6, the film forming rate is ≤0.2 nm / s.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] The camouflage stealth skin based on structural color prepared by the present invention has stable performance, radiation resistance, long service life, strong color customization capability, and can be customized in a variety of colors. At the same time, the raw materials for preparing the camouflage skin of the present invention are easy to obtain and the preparation method is simple. It can not only realize batch preparation, but also is green, environmentally friendly and pollution-free. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of the camouflage stealth skin based on structural color of the present invention;

[0026] Figure 2 This is a flow chart for preparing a camouflage stealth skin based on structural color according to the present invention;

[0027] Figure 3 The spectrum curve and color effect diagram of the camouflage stealth skin based on structural color of the present invention;

[0028] Figure 4 This is a rendering of the camouflage stealth skin based on structural color of the present invention;

[0029] Figure 5 This is a spectrum curve diagram of the structural color-based camouflage stealth skin prepared in Example 1 of the present invention;

[0030] Figure 6 This is a schematic diagram of the angle-insensitive camouflage stealth skin based on structural color prepared in Example 1 of the present invention;

[0031] Figure 7 This is an application effect diagram of the camouflage stealth skin based on structural color of the present invention.

[0032] Description of reference numerals:

[0033] In the figure, 1, base layer; 2, first reflective layer; 3, intermediate dielectric layer; 4, second reflective layer; 5, top protective layer. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0036] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The present description and examples are intended to be illustrative only.

[0037] like Figure 1 As shown, the present invention provides a camouflage stealth skin based on structural color. The skin comprises, from bottom to top, a base layer 1, a first reflective layer 2, an intermediate dielectric layer 3, a second reflective layer 4, and a top protective layer 5. The material of the first reflective layer 2 is selected from Al, Ag, or Au. Based on the FP resonance mechanism, the present invention designs an FP-type multilayer film structural color. This film is insensitive to incident light angle, exhibits stable physical and chemical properties, and can be customized in various colors by varying the film layer configuration.

[0038] In a specific embodiment, the material of the base layer 1 is aluminum foil or PET film.

[0039] In a specific embodiment, the material of the intermediate dielectric layer 3 is silicon or germanium. The thickness of the intermediate dielectric layer 3 determines the location of the trough, that is, the color hue. Furthermore, the use of the aforementioned high-refractive-index material for the intermediate dielectric layer 3 of the present invention enables a thinner film configuration. This ultra-thin structure ensures that the color and spectral performance of the asymmetric, ultra-thin structural color display remain virtually unchanged over a wide field of view.

[0040] In a specific embodiment, the material of the second reflective layer 4 is selected from one of Al, Ag, or Au. The material of the second reflective layer 4 of the present invention can be a metal material with low absorption and high reflectivity in the visible light band. The material of the second reflective layer 4 of the present invention is translucent, allowing incident light to enter the intermediate dielectric layer 3 and generate FP resonance. The thickness of the second reflective layer 4 determines the height of the reflection trough, i.e., the color brightness.

[0041] In a specific embodiment, the material of the top protective layer 5 is SiO 2 or Al 2 O 3 .

[0042] Another object of the present invention is to provide a method for preparing a camouflage stealth skin based on structural color, which specifically comprises the following steps:

[0043] S1. After cleaning and drying the substrate, place it in the vacuum chamber of the electron beam evaporation coating machine, and then pump the vacuum chamber to a vacuum degree of <3.0x10 -3 Pa, and then clean the substrate with an ion source filled with argon;

[0044] S2. Design the film system according to actual needs and determine the coating materials and thickness of each layer;

[0045] S3. According to the film system designed in step S2, a first reflective layer 2 is plated on the base layer 1 obtained in step S1;

[0046] S4. Depositing the intermediate dielectric layer 3 on the first reflective layer 2 obtained in step S3 using an electron beam evaporation coating machine;

[0047] S5. Depositing the second reflective layer 4 on the intermediate dielectric layer 3 obtained in step S4 using an electron beam evaporation coating machine;

[0048] S6. Using an electron beam evaporation coating machine, a top protective layer 5 is evaporated on the second reflective layer 4 obtained in step S5 to obtain a camouflage stealth skin based on structural color.

[0049] In a specific embodiment, in step S3 , the film forming rate is 0.3 nm / s.

[0050] In a specific embodiment, in step S4, the film forming rate is 0.2 nm / s.

[0051] In a specific embodiment, in step S5 , the film forming rate is 0.2 nm / s.

[0052] In a specific embodiment, in step S6, the film forming rate is 0.2 nm / s.

[0053] Based on the FP resonance effect, the present invention proposes to use a high-refractive-index lossy dielectric material as the FP cavity material and designs the above-mentioned structural color system, which is an asymmetric ultra-thin FP cavity composed of a bottom reflector / high-refractive-index intermediate dielectric layer 3 / top semi-transparent and semi-reflective mirror structure. In the structural design, the top semi-transparent and semi-reflective mirror 4 is translucent, allowing incident light to enter the intermediate dielectric layer 3 and generate FP resonance. Among them, the thickness of the top semi-transparent and semi-reflective mirror 4 determines the height of the reflection trough, that is, the color brightness; the thickness of the intermediate dielectric layer 3 determines the position of the trough, that is, the color hue. The bottom reflector film and the substrate are thick enough to prevent the incident light from passing through. The high refractive index of the intermediate dielectric layer 3 allows the structure to have a thinner film configuration. The ultra-thin structural configuration makes the color and spectral performance of the asymmetric ultra-thin structural color almost unchanged within a wide field of view.

[0054] The technical effects of the present invention are described below with reference to specific embodiments.

[0055] Example 1

[0056] The film layer configuration of the structural color camouflage stealth skin of this embodiment is as follows: flexible aluminum foil is used as the substrate, and the film layer structure is Al / Si / Ag / SiO2. The preparation method of the structural color camouflage stealth skin of this embodiment is as follows: Figure 3 As shown, the details are as follows:

[0057] S1. After cleaning and drying the substrate, place it in the vacuum chamber of the electron beam evaporation coating machine, and then pump the vacuum chamber to a vacuum degree of <3.0x10 -3 Pa, and then clean the substrate with an ion source filled with argon;

[0058] S2. Design the film system according to actual needs, determine the coating materials and thickness of each layer, in this embodiment, the coating materials and thickness of each layer are: 200nmAl / 20~60nmSi / 15nmAg / 10nmSiO2;

[0059] S3. According to the film system designed in step S2, a first reflective layer 2 is deposited on the base layer 1 obtained in step S1 at a film forming rate of 0.3 nm / s;

[0060] S4. Using an electron beam evaporation coating machine to deposit the intermediate dielectric layer 3 on the first reflective layer 2 obtained in step S3, the film forming rate is 0.2nm / s;

[0061] S5. Using an electron beam evaporation coating machine to deposit the second reflective layer 4 on the intermediate dielectric layer 3 obtained in step S4, the film forming rate is 0.2nm / s;

[0062] S6. Using an electron beam evaporation coating machine, a top protective layer 5 is evaporated on the second reflective layer 4 obtained in step S5 to obtain a camouflage stealth skin based on structural color, with a film forming rate of 0.2 nm / s.

[0063] The performance of the camouflage stealth skin based on structural color was tested, and the test results are as follows: Figure 5 and Figure 6 As shown, Figure 5 This is a spectrum curve diagram of the camouflage stealth skin based on structural color prepared in this embodiment. Figure 6 This is a schematic diagram of the angle-insensitive camouflage stealth skin based on structural color prepared in this embodiment.

[0064] Figure 7 This is an application effect diagram of the structural color camouflage stealth skin prepared in Example 1 of the present invention. Figure 7 As shown, the camouflage pattern is cut into various shapes to obtain the required camouflage skin.

[0065] It can be seen from the above results that the camouflage stealth skin based on structural color prepared by the present invention has stable performance, radiation resistance, long service life, strong color customization capability, and can be customized in a variety of colors. At the same time, the raw materials for preparing the camouflage skin of the present invention are easy to obtain and the preparation method is simple. It can not only realize batch preparation, but also is green, environmentally friendly and pollution-free.

[0066] Although the present invention is disclosed as above, the scope of protection disclosed by the present invention is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for preparing a camouflage stealth skin based on structural color, characterized in that: The preparation method specifically comprises the following steps: The flexible aluminum foil is used as the substrate, and the film structure is Al / Si / Ag / SiO2. S1. After cleaning and drying the substrate, place it in the vacuum chamber of the electron beam evaporation coating machine, and then pump the vacuum chamber to a vacuum degree of <3.0x10 -3 Pa, and then clean the substrate with an ion source filled with argon; S2. Design the film system based on actual needs and determine the coating materials and thickness of each layer: 200nmAl / 20-60nmSi / 15nmAg / 10nmSiO2; S3. According to the film system designed in step S2, a first reflective layer (2) is plated on the base layer (1) obtained in step S1 at a film forming rate of 0.3 nm / s; S4. Using an electron beam evaporation coating machine, an intermediate dielectric layer (3) is deposited on the first reflective layer (2) obtained in step S3 at a film forming rate of 0.2 nm / s; S5. Using an electron beam evaporation coating machine, a second reflective layer (4) is deposited on the intermediate dielectric layer (3) obtained in step S4 at a film forming rate of 0.2 nm / s; S6. Using an electron beam evaporation coating machine, a top protective layer (5) is evaporated on the second reflective layer (4) obtained in step S5 to obtain a camouflage stealth skin based on structural color, with a film forming rate of 0.2 nm / s.

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