Multispectral compatible camouflage and radiant heat management device and multispectral camouflage system based on same

Abstract

The invention discloses a multispectral compatible camouflage and radiant heat management device and a multispectral camouflage system based on the same, relates to the field of multispectral camouflage materials and heat management, and aims to solve the problems of poor spectrum compatibility, narrow bandwidth, insufficient heat management and high angle sensitivity in the prior art. A phase change material layer is arranged on the metal substrate layer, and a phase regulation and control layer of a chessboard structure is arranged on the phase change material layer. According to the invention, the radar scattering cross section is large, the specular reflectance is very low, the performance can still be maintained in the incidence angle range of 0-30 degrees, the reflectance is not sensitive to the incidence angle and the polarization state, laser stealth, radar stealth and infrared camouflage can be realized, the spectrum compatibility is good, the bandwidth is wide, dynamic heat dissipation in a non-window can be realized, and the performance is stable. And the heat management effect is achieved.

Description

Technical Field

[0001] The present invention relates to the field of multi-spectral camouflage materials and thermal management technology, and in particular to a multi-spectral compatible camouflage and radiation thermal management device and a multi-spectral camouflage system based on the device. Background Art

[0002] Traditional single-band stealth technologies (such as infrared or radar stealth) are unable to meet the requirements of modern multi-spectral detection methods. In existing technologies, stealth structures based on absorption or reflection have the following problems: 1. Poor spectral compatibility: Traditional stealth materials typically target only a single wavelength (such as visible light or infrared), making it difficult to simultaneously address the combined detection requirements of visible light, lasers (1.06 μm, 1.55 μm), and different infrared windows (3-5 μm, 8-14 μm). Existing technologies conflict with the performance requirements of visible light camouflage and infrared / laser stealth (e.g., the conflict between low emissivity and high absorptivity), making multispectral compatibility difficult to achieve. 2. Narrow bandwidth: Existing metasurface structures have limited bandwidth in the radar stealth band (e.g., 8-14 μm); 3. Inadequate thermal management: Existing infrared stealth materials lack efficient heat dissipation in the low-emissivity windows (3-5 μm and 8-14 μm). Heat accumulates on the target surface in high-temperature environments, making it easily detectable by infrared detectors. Furthermore, passive heat dissipation in the non-window area (5-8 μm) is not optimized, impacting the long-term stability of the equipment. 4. High angular sensitivity: Stealth performance decreases significantly at large incident angles.

[0003] Chinese patent CN119846753A discloses a multilayer film that is compatible with stealth and radiative heat dissipation in the H, K, mid-wave infrared, and long-wave infrared bands. The technical solution adopted is as follows: it includes a substrate, a metal reflective layer, a photonic crystal layer fused with a lossy medium, and an anti-reflection layer in the H and K bands. The absorptivity in the H and K bands is greater than 0.5, the emissivity in the mid-wave infrared and long-wave infrared bands is less than 0.5, and the emissivity in the very long-wave infrared band is greater than 0.5; the photonic crystal layer fused with the lossy medium is a multilayer structure, composed of alternating layers of dielectric layers of multiple high and low refractive index dielectric materials.

[0004] This existing patent adopts a static design, cannot respond to temperature changes, and does not cover laser and radar bands.

[0005] Chinese patent CN119553229A discloses a multi-spectral compatible stealth coating based on a high-entropy alloy and its preparation method. The technical solution employed utilizes magnetron sputtering technology to prepare a high-entropy alloy thin film. Through scientific screening and optimized combination of elements, and by regulating magnetron sputtering parameters, the material composition and structure can be efficiently customized, resulting in a uniform, dense, and high-performance high-entropy alloy film. Test results indicate that the high-entropy alloy coating has an absorptivity of approximately 0.95 in the visible light band and an emissivity of approximately 0.05 in the infrared band, achieving multi-spectral compatible stealth across the visible and infrared spectral ranges.

[0006] Although this existing patent performs well in the visible light / infrared band (absorption rate 0.95 / emissivity 0.05), it is still a static material and cannot cope with temperature fluctuations or laser / radar detection. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the existing defects and provide a multi-spectral compatible camouflage and radiation heat management device and a multi-spectral camouflage system based on the device, which can effectively solve the problems in the background technology.

[0008] To achieve the above objectives, the present invention first discloses a multi-spectral compatible camouflage and radiation heat management device, which adopts a technical solution comprising a metal base layer, a phase change material layer on the metal base layer, and a phase control layer with a checkerboard structure on the phase change material layer; The phase control layer includes a base layer and a unit layer. The base layer is a continuous planar structure, and the unit layer is a protrusion arranged intermittently on the base layer. The arrangement of the unit layer on the base layer is a checkerboard-like staggered arrangement.

[0009] As a preferred technical solution of the present invention, the metal base layer is at least one of gold and silver, and has a thickness of 80-120 nm.

[0010] As a preferred technical solution of the present invention, the phase change material layer is a GST (germanium antimony tellurium) layer with a thickness of 200-300 nm, and a phase transition temperature between the crystalline state and the amorphous state is 150-200°C.

[0011] As a preferred technical solution of the present invention, the phase control layer is a zinc sulfide layer with a thickness gradient of 100-2200 nm, a period of 25-35 μm, and a phase difference between adjacent chessboard units of 180°±37°.

[0012] As a preferred technical solution of the present invention, the protrusion size of the unit layer is (10~20) μm×(10~20) μm, and the protrusion thickness of the unit layer is linearly adjusted according to the stealth requirements.

[0013] The present invention also discloses a multi-spectral camouflage system, which adopts a technical solution that includes multiple multi-spectral compatible camouflage and radiation heat management devices as described above, and the multi-spectral compatible camouflage and radiation heat management devices are distributed in an array.

[0014] Compared with existing technologies, the present invention offers the following advantages: By sequentially placing a phase-change material layer and a checkerboard-structured phase-modulation layer on a metal substrate, the present invention can reduce the radar cross section (RCS) in the 8-14 μm band by at least 10 dB and maintain a specular reflectivity below 3%, maintaining this performance at an angle of incidence of 0-30°. Dynamically adjusting the emissivity in the non-atmospheric window (5-8 μm) through GST phase transition results in an emissivity of 0.10-0.15 in the amorphous state and 0.60-0.70 in the crystalline state. In the near-infrared band (1.06 μm and 1.55 μm), the specular reflectivity is no higher than 0.1%, and the reflectivity is insensitive to the angle of incidence (0-45°) and polarization state. The present invention can achieve laser stealth, radar stealth, and infrared camouflage, with excellent spectral compatibility, wide bandwidth, and dynamic heat dissipation outside the window, achieving effective thermal management. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the super surface structure of the present invention; Figure 2 This is the ideal emission spectrum diagram of the present invention; Figure 3 This is a diagram showing the simulation results of phase difference and reflection spectrum under amorphous GST of the present invention; Figure 4 This is a diagram showing the simulation results of phase difference and reflection spectrum under the crystalline GST of the present invention; Figure 5 This is a diagram showing the simulation results of the atmospheric window and non-atmospheric window reflection spectra under the amorphous GST of the present invention; Figure 6 This is a diagram showing the simulation results of the atmospheric window and non-atmospheric window reflection spectra under the crystalline GST of the present invention; Figure 7 This is a diagram showing the simulation results of the near-infrared reflectance spectrum of the amorphous GST of the present invention; Figure 8 This is a diagram showing the simulation results of the near-infrared reflectance spectrum of the crystalline GST of the present invention; Figure 9 The figure shows the simulation results of RCS (radar cross section) reduction under different incident angles for the amorphous GST of the present invention; Figure 10 This is a diagram showing the RCS reduction simulation results at different incident angles for the crystalline GST of the present invention; Figure 11 The simulation results of the reflection spectrum of the amorphous GST under different incident angles of the present invention are shown in FIG. Figure 12 This is a diagram showing the simulation results of the reflection spectrum of the crystalline GST at different incident angles; Figure 13 (a) is a simulation result of the absorption characteristics of the amorphous GST of the present invention under transverse magnetic incident light; Figure 13 (b) is a simulation result of the absorption characteristics of the amorphous GST of the present invention under transverse electric incident light; Figure 13 (c) is a simulation result of the absorption characteristics of the crystalline GST of the present invention under transverse magnetic incident light; Figure 13 (d) is a simulation result of the absorption characteristics of the crystalline GST of the present invention under transverse electric incident light; Figure 14 This is a comparison chart of the thermal management effects of the present invention; Figure 15 This is the abnormal scattered light field distribution and theoretical verification diagram of the present invention; Figure 16 The corresponding emissivity spectra of different metal substrates at different wavelengths (3-15 μm) when GST is in the amorphous state (aGST) structure are shown; Figure 17 The corresponding reflectivity spectra of different metal substrates at different wavelengths (3-15 μm) when GST is in the amorphous state (aGST) structure are shown; Figure 18 The corresponding reflectivity spectra of different metal substrates at different wavelengths (1-2 μm) when GST is in the amorphous state (aGST) structure are shown; Figure 19 The corresponding emissivity spectra of different metal substrates at different wavelengths (3-15 μm) when GST is in the crystalline state (cGST) structure are shown; Figure 20 The corresponding reflectance spectra of different metal substrates at different wavelengths (3-15 μm) when GST is in the crystalline state (cGST) structure are shown; Figure 21 The corresponding reflectivity spectra of different metal substrates at different wavelengths (1-2 μm) when GST is in the crystalline state (cGST) structure are shown; Figure 22 The reflectivity spectra of GST at different periods (20-40 μm) are shown when it is in the amorphous state (aGST) structure; Figure 23 The reflectivity spectra of GST at different periods (20-40 μm) are shown when it is in the crystalline state (cGST) structure; Figure 24The reflectivity spectra of GST in the amorphous state (aGST) at different small unit sizes (10-15 μm) are shown; Figure 25 The reflectivity spectra of GST in the crystalline state (cGST) at different small unit sizes (10-15 μm) are shown. DETAILED DESCRIPTION

[0016] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0017] 1. Determine the metal base material (1) Material selection requirements ① It has low emissivity in the infrared atmospheric window (3-5 micron and 8-14 micron bands) to achieve infrared thermal camouflage; ② Low reflectivity in the 8-14 micron band to achieve lidar stealth; ③ Low emission at 1.55 μm and 1.06 μm in the near infrared to achieve lidar stealth.

[0018] (2) Experimental verification Gold, silver, aluminum, chromium, nickel and zinc were used as substrates to prepare samples and the reflectivity spectra were tested. The test results are as follows: Figures 16 to 21 The specific values ​​are shown in the following table:

[0019] From the above results, we can see that metal chromium and metal nickel are not suitable for use as substrates because of their high emissivity (greater than 0.3) in the atmospheric window. The thermal expansion coefficient of aluminum is very high, and aluminum used in the laboratory is easy to damage the crucible, so it is also not adopted. Therefore, gold, silver, and zinc can be used as substrates.

[0020] 2. Structural dimension verification Verification results are as follows Figures 22 to 25 The specific detection values ​​are shown in the following table:

[0021] The verification results show that regardless of whether GST is in the crystalline or amorphous state, if the unit period is too small, the reflectivity of the structure will increase at 8-14 microns, affecting the radar stealth effect. The recommended optimal period is 30-40 microns. Whether in the crystalline or amorphous state of GST, if the cell size is too small, the area duty cycle will decrease, causing the structure's reflectivity to increase in the 8-14 micron range, compromising radar stealth. Therefore, circular or triangular structures are not recommended for the upper layer, as they reduce the area duty cycle and increase reflectivity. Therefore, a checkerboard structure with a 100% area duty cycle is recommended to minimize reflectivity. For consistency, the cell size refers to the width of the checkerboard grid at the maximum thickness of the zinc sulfide layer. Example 1

[0022] like Figure 1 As shown, this embodiment discloses the first implementation of the present invention. First, a multi-spectral compatible camouflage and radiation heat management device is disclosed. The technical solution adopted is to use a gold layer with a thickness of 100nm as a metal base layer to provide high reflective properties, and set a 250nm thick GST layer on the gold layer as a phase change material layer, which can adjust the emissivity in the mid- and far-infrared bands by the transformation between the crystalline and amorphous states. A phase control layer is set above the GST layer. The phase control layer adopts a zinc sulfide layer, which includes a 100nm thick base layer and a 2200nm thick unit layer. The unit layer has a size of 10μm×10μm, and the unit layer is distributed in a checkerboard shape with a period of 25μm. The phase difference between adjacent unit layers is 180°. Abnormal scattering is achieved by adjusting the phase gradient of zinc sulfide, thereby reducing the mirror reflectivity.

[0023] The reflectance spectrum simulation of the multi-spectral compatible camouflage and radiation heat management device is carried out, and its ideal emission spectrum is shown as follows Figure 2 As shown in the figure, the curve of the emissivity of the device under ideal conditions changes with wavelength, covering visible light, near infrared (such as 1.06μm, 1.55μm laser bands), mid-infrared (3-5μm) and far infrared (8-14μm) bands. The emissivity is kept low in the infrared atmospheric window to disguise heat, and the emissivity is adjusted (0.12-0.65) through GST phase change in the non-window to ensure thermal management effect. The spectral bandwidth is wide (covering 1-14μm), and the compatibility is better than traditional single-band materials. Figure 3 、 Figure 4 Shown are the simulation results of the phase difference and reflection spectrum of amorphous GST and crystalline GST; it shows the phase difference distribution (about 180°) of adjacent units in the phase control layer when the GST layer is in the amorphous and crystalline states, as well as the corresponding reflection spectrum (reflectivity varies with wavelength). It is concluded that whether in the amorphous or crystalline state, the device can effectively reduce the radar scattering cross section (RCS drop ≥ 10dB) and maintain low mirror reflectivity to support radar stealth. At the same time, the design of the phase control layer ensures angle insensitivity (stable performance at an incident angle of 0-30°). Figure 5 、 Figure 6The following are the simulation results of the reflection spectrum under the atmospheric window (3-5 μm, 8-14 μm) and the non-atmospheric window (5-8 μm). Figure 5 and Figure 6 It can be seen that the device can maintain an emissivity below 0.2 in the atmospheric window, thereby reducing the radiation temperature, and can achieve dynamic adjustment through GST phase change in the non-atmospheric window. In addition, the device exhibits extremely low mirror reflectivity in both the crystalline and amorphous states of the GST layer at 8-14 μm. Figure 7 、 Figure 8 As shown, this embodiment exhibits extremely low specular reflectivity in the near-infrared band (1.06μm, 1.55μm) through thin film interference and material absorption characteristics, and its specular reflectivity is less than 0.1%, thereby having excellent lidar stealth characteristics; Figure 9 、 Figure 10 As shown, it can be seen that under different incident angles of 0-30°, the GST layer in the crystalline and amorphous states of the present invention reduces the RCS by 10dB or more, and the reduction of RCS can further improve the radar stealth performance; Figure 11 、 Figure 12 As shown, within the incident angle range of 0-30°, the device has very low reflectivity in both the amorphous and crystalline states, and has strong radar stealth performance; Figure 13 As shown in the figure, the GST layer in the amorphous state and the crystalline state has an extremely low emissivity at large angles in the atmospheric window under transverse magnetic incident light and transverse electric incident light, showing angle-insensitive infrared thermal camouflage; in addition, the GST layer in the crystalline state still has a high emissivity at large angles in the non-atmospheric window to achieve radiative heat dissipation. Figure 14 As shown in Figure 1, the present invention can achieve radiative heat insulation at low temperatures (GST in an amorphous state) and radiative heat dissipation at high temperatures (GST in a crystalline state), thereby achieving thermal management. Low-temperature heat insulation and high-temperature heat dissipation solve the problem of heat accumulation in traditional materials and improve equipment durability. The design was verified using the theoretical model FDTD (such as phase gradient metasurface theory), and the results are shown below. Figure 15 As shown, it shows the abnormal scattered light field distribution (such as scattering angle or energy distribution) of the phase control layer. It can be seen that there is indeed abnormal scattering, which causes the reflectivity of the structure of this embodiment to decrease at a wavelength of 8-14 μm.

[0024] This embodiment also discloses a multi-spectral camouflage system, which adopts a technical solution that includes multiple multi-spectral compatible camouflage and radiation heat management devices as described above, and the multi-spectral compatible camouflage and radiation heat management devices are distributed in a rectangular array. Example 2

[0025] The difference between this embodiment and Example 1 is that a multi-spectral compatible camouflage and radiation heat management device uses an 80nm thick gold layer as a metal base layer, a 200nm thick GST layer is arranged on the gold layer as a phase change material layer, and a phase control layer is arranged above the GST layer. The phase control layer adopts a zinc sulfide layer, which includes a 200nm thick base layer and a 2100nm thick unit layer. The unit layer size is 15μm×15μm, the unit layer is distributed in a checkerboard shape, the period is 30μm, and the phase difference between adjacent unit layers is 143°. Example 3

[0026] The difference between this embodiment and Example 1 is that a multi-spectral compatible camouflage and radiation heat management device uses a 120nm thick gold layer as a metal base layer, a 300nm thick GST layer is arranged on the gold layer as a phase change material layer, and a phase control layer is arranged above the GST layer. The phase control layer adopts a zinc sulfide layer, which includes a 150nm thick base layer and a 2150nm thick unit layer. The unit layer size is 20μm×20μm, the unit layer is distributed in a checkerboard shape, the period is 35μm, and the phase difference between adjacent unit layers is 217°. Example 4

[0027] The difference between this embodiment and embodiment 1 is that the metal base layer is a silver layer.

[0028] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A multi-spectral compatible camouflage and radiant heat management device, characterized by: The method comprises a metal base layer, a phase change material layer is provided on the metal base layer, and a phase control layer in a checkerboard structure is provided on the phase change material layer; The phase control layer includes a base layer and a unit layer. The base layer is a continuous planar structure, and the unit layer is a protrusion arranged intermittently on the base layer. The arrangement of the unit layer on the base layer is a checkerboard-like staggered arrangement.

2. The multi-spectral compatible camouflage and radiation heat management device according to claim 1, characterized in that: The metal base layer is at least one of gold and silver, and has a thickness of 80-120 nm.

3. The multi-spectral compatible camouflage and radiant heat management device according to claim 1, characterized in that: The phase change material layer is a GST layer with a thickness of 200-300 nm.

4. The multi-spectral compatible camouflage and radiant heat management device according to claim 1, characterized in that: The phase control layer is a zinc sulfide layer with a thickness gradient of 100-2200 nm, a period of 25-35 μm, and a phase difference of 180°±37° between adjacent chessboard units.

5. The multi-spectral compatible camouflage and radiation heat management device according to claim 1 or 4, characterized in that: The protrusion size of the unit layer is (10-20) μm×(10-20) μm.

6. A multi-spectral camouflage system, characterized by: It comprises a plurality of multi-spectrum compatible camouflage and radiation heat management devices as described in any one of claims 1 to 5, and the multi-spectrum compatible camouflage and radiation heat management devices are distributed in an array.

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