Infrared-radar compatible stealth skin and parameterized design method and preparation method thereof

Abstract

The application discloses an infrared-radar compatible stealth skin and a parameterized design method and a preparation method thereof, comprising a low infrared emission layer, a microwave absorption layer and a total reflection layer arranged in sequence from top to bottom, wherein the low infrared emission layer comprises a first ITO layer, a first PET layer and a first transparent layer arranged in sequence from top to bottom, the microwave absorption layer comprises a second ITO layer, a second PET layer and a second transparent layer arranged in sequence from top to bottom, and the total reflection layer comprises a third ITO layer and a third PET layer. Compared with the prior art, the application adopts the structural form of the low infrared emission layer / microwave absorption layer / total reflection layer, selects the nested structure of the surface periodic array ITO patch and the internal square ring patch, and simultaneously realizes the infrared-radar compatible stealth and the visible light transmission.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of skin, and particularly relates to an infrared-radar compatible stealth skin and a parameterized design method and preparation method thereof. BACKGROUND

[0002] With the rapid development of modern strategic weapons, the battlefield environment becomes increasingly complex, and the self-protection of various military equipment under the modern multi-frequency band combination and multi-gradient depth detection technology is particularly important. The compatible stealth technology has developed rapidly, especially the infrared-radar compatible stealth. However, the principles of infrared stealth and radar stealth are incompatible. Therefore, metamaterials with extraordinary physical properties such as negative refraction and perfect lens can be artificially controlled to achieve electromagnetic parameters, and a large number of structure designs that can achieve compatible stealth have been born.

[0003] The design idea of the existing compatible stealth skin is to propose a special structure, and then use the algorithm iteration or digital cluster method to make the structure achieve certain performance, and finally perform experimental verification. Due to the lack of electromagnetic theory guidance and the complexity of the designed structure, it takes a lot of time to get a stealth skin that meets the requirements. Moreover, the already designed structure is difficult to further optimize according to the changes in application requirements due to poor repeatability. Based on the analysis and guidance of electromagnetic theory, the application proposes an infrared-radar compatible stealth skin and a parameterized design method and preparation method thereof, which can be designed efficiently and purposefully, so as to quickly meet the changes in application requirements.

[0004] Chinese patent CN114465015A discloses a low-infrared-emissivity light-transmitting flexible metamaterial wave absorber, which comprises a transparent flat plate layer, a transparent dielectric substrate layer, and a transparent reflection layer from top to bottom. The second transparent conductive film comprises three square ring films with equal ring width and gap. The infrared emissivity can be 0.36, and the absorption rate is above 90% within 5.57-18.87GHz. However, the design method of the application is to optimize the fixed structure, which lacks parameterized analysis and theoretical guidance based on electromagnetic theory. The infrared emissivity is higher than 0.271 of the application. Due to the same size of the ring structure, the medium-high frequency absorption peaks overlap, and the actual absorption bandwidth is only 13.3GHz. This is far from enough in real application, and therefore there is an urgent need for a structure and parameterized design method and preparation method that can improve the actual absorption bandwidth. SUMMARY

[0005] The application aims to provide an infrared-radar compatible stealth skin and a parameterized design method and preparation method thereof, which can be adjusted according to the different shapes of the stealth target and can be realized in multiple fields.

[0006] To achieve the above object, the technical scheme adopted by the present application is: an infrared-radar compatible stealth skin, comprising a low infrared emission layer, a microwave absorption layer and a total reflection layer arranged in sequence from top to bottom, wherein the low infrared emission layer comprises a first ITO layer, a first PET layer and a first transparent layer arranged in sequence from top to bottom, the microwave absorption layer comprises a second ITO layer, a second PET layer and a second transparent layer arranged in sequence from top to bottom, and the total reflection layer comprises a third ITO layer and a third PET layer.

[0007] The present application adopts the above structure, wherein the low infrared emission layer at the top plays a role of preventing the emission of infrared waves and frequency selection, which can ensure the low infrared emissivity of the skin and the smooth passing of radar waves; the microwave absorption layer in the middle resonantly absorbs the entering radar waves, so that the radar waves are lost; the total reflection layer at the bottom can reflect the radar waves that are not completely absorbed to the microwave absorption layer for full absorption; since optical transparent materials are used, visible light can smoothly pass through.

[0008] As a preferred, the first ITO layer is in a periodic array, the second ITO layer is in a square ring arrangement and the number of the square rings is 1, 2 or 3.

[0009] As a preferred, the sheet resistance of the first ITO layer is 5-10 Ω / sq, the sheet resistance of the second ITO layer is 70-100 Ω / sq, and the sheet resistance of the third ITO layer is <8 Ω / sq.

[0010] As a preferred, the thickness of the first PET layer, the second PET layer and the third PET layer is all <0.3 mm.

[0011] Another object of the present application is to provide a parameterized design method for an infrared-radar compatible stealth skin, which specifically comprises the following steps:

[0012] S1, obtaining an infrared emissivity and a microwave absorption bandwidth;

[0013] S2, obtaining a surface ratio corresponding to the first ITO layer according to the numerical value of the infrared emissivity, and obtaining a width corresponding to the first ITO layer according to the frequency range of the microwave absorption bandwidth;

[0014] S3, obtaining a low-frequency absorption peak position according to the low-frequency range of the microwave absorption bandwidth, and obtaining the total thickness of the first transparent layer and the second transparent layer according to the low-frequency absorption peak position;

[0015] S4, obtaining the size parameters of the ring structure in the microwave absorption layer according to the high-frequency absorption peak position in the frequency range of the microwave absorption bandwidth for verifying the target parameter requirements.

[0016] As preferred, in the step S2, the surface ratio corresponding to the first ITO layer is processed according to the following formula:

[0017] ε MCSM = ε ITO S ITO + ε PET (1-S ITO )

[0018] Wherein, ε MCSM is the infrared emissivity of the stealth skin, ε ITO and ε PET are the infrared emissivity of the first ITO layer 101 and the first PET layer respectively, S ITO is the surface ratio of the first ITO layer; the width corresponding to the first ITO layer is processed according to the following formula:

[0019]

[0020] Wherein f is the resonance frequency, c is the speed of light in vacuum, n is the refractive index of the substrate material, and w is the width of the ITO patch;

[0021] As preferred, in the step S3, the thickness d of the medium is determined by the position of the low-frequency absorption peak, and the corresponding relationship is as follows

[0022]

[0023] Wherein d is the total thickness of the first transparent layer and the second transparent layer, n is the influence factor, u is the wave speed of the electromagnetic wave in the medium, and f is the center frequency of the low-frequency absorption peak.

[0024] The third object of the present application is to provide a preparation method for an infrared-radar compatible stealth skin, which comprises respectively preparing a low infrared emissivity layer, a microwave absorption layer and a total reflection layer, and then bonding the low infrared emissivity layer, the microwave absorption layer and the total reflection layer in sequence, the preparation method of the low infrared reflection layer is the same as that of the microwave absorption layer, and specifically comprises the following steps:

[0025] S1, drop glue into a circular silicon wafer, place the silicon wafer in a spin coater for spin coating treatment, then paste the ITO film on the surface of the silicon wafer, and then place it in a vacuum chamber with a vacuum degree of <3.0*10 -3 Pa, heat and keep warm after heating;

[0026] S2, place the ITO film obtained in step S1 in a glue coating and developing machine for spin coating photoresist, then use a photoetching machine for photoetching treatment, then place it in an etching solution for wet etching, then use acetone solution to remove the photoresist, and finally separate it from the silicon wafer by placing it in an alcohol solution.

[0027] Preferably, in the step S1, the components of the glue are polydimethylsiloxane and SE1700 curing agent, and the mass ratio of the polydimethylsiloxane and the SE1700 curing agent is 10:1.

[0028] Preferably, the spin coating step is as follows: spin coating at 500 r / min for 10 s, and then spin coating at 800 r / min for 40 s.

[0029] Preferably, the temperature of the temperature rising is 85 DEG C, and the holding time is 2 h.

[0030] Preferably, in the step S2, in the photoetching process, the exposure dose is 110 mJ / cm 2 .

[0031] Preferably, the etching solution is TE-100.

[0032] Preferably, the etching time of the ITO film with a resistance of 5 Omega / sq is 140 s, and the etching time of the ITO film with a resistance of 80 Omega / sq is 15 s.

[0033] Compared with the prior art, the present application has the following advantages:

[0034] 1. The structure form of low infrared emission layer / microwave absorption layer / total reflection layer is adopted, the nested structure of the surface periodic array ITO patch and the internal square ring patch is selected, and the infrared radar compatible stealth and visible light transmission are realized at the same time;

[0035] 2. The parameterization processing can reduce the design time, reduce the design difficulty, improve the performance parameters of the designed device, and make the tuning of the stealth performance more convenient;

[0036] 3. The photoetching process guarantees the size precision of the metamaterial and avoids surface pollution, the multi-film layer structure reduces the preparation difficulty, lays a foundation for large-area batch preparation, and the method can make the prepared skin performance stable, realize long-time infrared-radar stealth, has flexibility, angle stability and visible light transmission, can be adjusted according to the different shapes of the stealth target, and can realize multi-field generalization. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 It is a structure schematic diagram of the present application facing infrared-radar compatible stealth skin;

[0038] Figure 2 It is an infrared emissivity relationship diagram of different square resistance ITO and PET;

[0039] Figure 3 It is a surface parameterization processing diagram of the low infrared emission layer;

[0040] Figure 4Figure for the relationship between the proportion of ITO and the infrared emissivity;

[0041] Figure 5 Figure for the relationship between the width of ITO patch and the resonant frequency;

[0042] Figure 6 Figure for the parameterization processing diagram of the single-ring structure of the second ITO layer 201 in the embodiment 1 of the present application;

[0043] Figure 7 Figure for the comparison between the simulation processing and the experimental processing of the infrared-radar compatible stealth skin prepared in the embodiment 1 of the present application;

[0044] Figure 8 Figure for the parameterization processing diagram of the double-ring structure of the second ITO layer 201 in the embodiment 2 of the present application;

[0045] Figure 9 Figure for the comparison between the simulation processing and the experimental processing of the infrared-radar compatible stealth skin prepared in the embodiment 2 of the present application;

[0046] Figure 10 Figure for the parameterization processing diagram of the three-ring structure of the second ITO layer 201 in the embodiment 3 of the present application;

[0047] Figure 11 Figure for the comparison between the simulation processing and the experimental processing of the infrared-radar compatible stealth skin prepared in the embodiment 3 of the present application;

[0048] Figure 12 Figure for the experimental test results of the infrared emissivity of the infrared-radar compatible stealth skin prepared in the embodiments 1-3 of the present application;

[0049] Figure 13 Figure for the visible light transmittance test results of the infrared-radar compatible stealth skin prepared in the embodiments 1-3 of the present application.

[0050] The reference signs: 1, low infrared emission layer, 2, microwave absorption layer, 3, total reflection layer, 101, first ITO layer, 102, first PET layer, 103, first transparent layer, 201, second ITO layer, 202, second PET layer, 203, second transparent layer, 301, third ITO layer, 302, third PET layer. DETAILED DESCRIPTION

[0051] In order to make the above objectives, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0052] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. Additionally, for a range of values of, for example, the upper limit and lower limit of the range are included in the range. Each intermediate value of the stated range and each smaller range that falls within the stated range are also included in the present application. The upper and lower limits of these smaller ranges can independently be included or excluded in the ranges.

[0053] Many modifications and variations of the present application described herein will be apparent to those of ordinary skill in the art from the foregoing detailed description of the application. Other embodiments of the application will be apparent to those of ordinary skill in the art from the foregoing detailed description of the application. The application described herein is merely exemplary in nature and is not intended to limit the application as described herein. The application described herein is intended to cover any and all modifications of the application within the scope of the claims.

[0054] The embodiment of the present application provides an infrared-radar compatible stealth skin, as shown in the drawings, comprising a low infrared emission layer 1, a microwave absorption layer 2 and a total reflection layer 3 arranged from top to bottom, wherein the low infrared emission layer 1 comprises a first ITO layer 101, a first PET layer 102 and a first transparent layer 103 arranged from top to bottom, the microwave absorption layer 2 comprises a second ITO layer 201, a second PET layer 202 and a second transparent layer 203 arranged from top to bottom, and the total reflection layer 3 comprises a third ITO layer 301 and a third PET layer 302. Figure 1 As shown in the drawings, comprising a low infrared emission layer 1, a microwave absorption layer 2 and a total reflection layer 3 arranged from top to bottom, wherein the low infrared emission layer 1 comprises a first ITO layer 101, a first PET layer 102 and a first transparent layer 103 arranged from top to bottom, the microwave absorption layer 2 comprises a second ITO layer 201, a second PET layer 202 and a second transparent layer 203 arranged from top to bottom, and the total reflection layer 3 comprises a third ITO layer 301 and a third PET layer 302.

[0055] The present application adopts the above structure, wherein the low infrared emission layer 1 at the top plays a role in preventing the emission of infrared waves and frequency selection, which can ensure the low infrared emissivity of the skin and the smooth passage of radar waves; the microwave absorption layer 2 in the middle resonantly absorbs the incoming radar waves, so that the radar waves are lost; the total reflection layer 3 at the bottom can reflect the radar waves that are not completely absorbed to the microwave absorption layer for full absorption; and since optical transparent materials are used, visible light can pass through smoothly.

[0056] In the embodiment, the first ITO layer 101 is in a periodic array, and the second ITO layer 201 is arranged in a square ring shape and the number of square rings is 1, 2 or 3.

[0057] In the embodiment, the material of the first transparent layer 103 is selected from one of PET, PMMA and PVC, and the material of the second transparent layer 203 is selected from one of PET, PMMA and PVC.

[0058] In the embodiment, the sheet resistance of the first ITO layer 101 is 5-10 Ω / sq, the sheet resistance of the second ITO layer 201 is 70-100 Ω / sq, and the sheet resistance of the third ITO layer 301 is <8 Ω / sq.

[0059] In the specific embodiment, the thickness of the first PET layer 102, the second PET layer 202 and the third PET layer 302 is all <0.3 mm.

[0060] Another object of the embodiment of the present application is to provide a parameterized design method for an infrared-radar compatible stealth skin, specifically comprising the following steps:

[0061] S1, obtaining the infrared emissivity and the microwave absorption bandwidth;

[0062] S2, obtaining the surface ratio of the second ITO layer 201 according to the numerical value of the infrared emissivity, and obtaining the width of the second ITO layer 201 according to the frequency range of the microwave absorption bandwidth;

[0063] S3, obtaining the low-frequency absorption peak position according to the low-frequency range of the microwave absorption bandwidth, and obtaining the total thickness of the first transparent layer 103 and the second transparent layer 203 according to the low-frequency absorption peak position;

[0064] S4, obtaining the size parameters of the annular structure in the microwave absorption layer 2 according to the high-frequency absorption peak position in the frequency range of the microwave absorption bandwidth for verifying the target parameter requirements.

[0065] In the specific embodiment, in step S2, the processing formula of the surface ratio corresponding to the first ITO layer 101 is as follows:

[0066] ε MCSM = ε ITO S ITO + ε PET (1-S ITO )

[0067] Wherein, ε MCSM is the infrared emissivity of the stealth skin, ε ITO and ε PET are the infrared emissivities of the first ITO layer 101 and the first PET layer 102 respectively, S ITO is the surface ratio of the first ITO layer 101, and the infrared emissivities of the first PET layer 102 and the first ITO layer 101 under different sheet resistances are as shown in Figure 2 For more convenient obtaining of the corresponding relationship between the ITO patch and the infrared emissivity, the surface of the low-infrared emissivity layer 1 is parameterized, as shown in Figure 3 In the case proposed in the present application, the ITO patch with a sheet resistance of 5Ω / sq is selected, and the corresponding relationship between the ratio and the infrared emissivity is as shown in Figure 4

[0068] The processing formula of the width corresponding to the first ITO layer 101 is as follows: ​

[0069]

[0070] where f is the resonance frequency, c is the speed of light in vacuum, n is the refractive index of the substrate material, and w is the width of the ITO patch.

[0071] In the case of PET as the substrate, the correspondence between the resonance frequency and the ITO patch size is as shown in Figure 5

[0072] In a specific embodiment, in step S3, the thickness d of the medium is determined by the position of the low-frequency absorption peak, and the correspondence between the two is as follows:

[0073]

[0074] where d is the total thickness of the first transparent layer 103 and the second transparent layer 203, n is the influence factor, u is the wave speed of the electromagnetic wave in the medium, and f is the center frequency of the low-frequency absorption peak.

[0075] A third object of the present application is to provide a preparation method for an infrared-radar compatible stealth skin, which comprises preparing a low infrared emission layer 1, a microwave absorption layer 2 and a total reflection layer 3 respectively, and then bonding the low infrared emission layer 1, the microwave absorption layer 2 and the total reflection layer 3 in sequence.

[0076] S1, after stirring the polydimethylsiloxane PDMS and the SE1700 curing agent uniformly at a mass ratio of 10:1, a glue is prepared, then the glue is added dropwise into a circular silicon wafer, and the silicon wafer is placed in a spin coater to spin at 500 r / min for 10 s and then at 800 r / min for 40 s, until the glue uniformly covers the surface of the silicon wafer, the ITO film is uniformly pasted on the surface of the silicon wafer, and then the silicon wafer is placed in a vacuum machine for two hours, and the vacuum degree of the vacuum chamber is extracted to <3.0x10 -3 Pa, and the temperature is heated to 85℃;

[0077] S2, after the ITO film obtained in step S2 is cleaned with alcohol, the ITO film is spin coated with photoresist in a glue coating and developing machine, and photoetching is continued, with an exposure dose of 110 mJ / cm 2 The ITO film is placed in a tin oxide / indium tin oxide etching solution (TE-100) for wet etching, and the etching time of the ITO film with a resistance of 5Ω / sq and 80Ω / sq is 140 s and 15 s respectively, then the ITO film is cleaned with deionized water and dried, the photoresist is removed with acetone solution, and finally the ITO film is separated from the silicon wafer by placing it in an alcohol solution.

[0078] ​The technical effects of the present application are described below in combination with specific embodiments.

[0079] Embodiment 1

[0080] The present embodiment provides an infrared-radar compatible stealth skin, which has the following parameters:

[0081] As shown in Figure 6 , the infrared-radar compatible stealth skin of the present embodiment includes, from top to bottom, a low infrared emission layer 1, a microwave absorption layer 2, and a total reflection layer 3, wherein the low infrared emission layer 1 includes, from top to bottom, a first ITO layer 101, a first PET layer 102, and a first transparent layer 103, the microwave absorption layer 2 includes, from top to bottom, a second ITO layer 201, a second PET layer 202, and a second transparent layer 203, and the total reflection layer 3 includes a third ITO layer 301 and a third PET layer 302, the first ITO layer 101 is arranged in a periodic array, the second ITO layer 201 is arranged in a square ring shape and the number of square rings is 1, the material of the first transparent layer 103 is PET, the material of the second transparent layer 203 is PET, the sheet resistance of the first ITO layer 101 is 5Ω / sq, the sheet resistance of the second ITO layer 201 is 80Ω / sq, the sheet resistance of the third ITO layer 301 is 5Ω / sq, and the thicknesses of the first PET layer 102, the second PET layer 202, and the third PET layer 302 are all 0.175mm.

[0082] According to the parameterization design method of the infrared-radar compatible stealth skin, the parameters of the present embodiment are designed as follows: the low infrared reflection layer 1 is: a first ITO layer 101 with a surface ratio of 81% + a first PET layer 102 with a thickness of 0.175mm + a first transparent layer 103 with a thickness of 1.5mm; the microwave absorption layer 2 is: a second ITO layer 201 with a single ring structure + a second PET layer 202 with a thickness of 0.175mm + a second transparent layer 203 with a thickness of 1.8mm; and the total reflection layer 3 is: a third ITO layer 301 + a third PET layer 302 with a thickness of 0.175mm.

[0083] Dimension parameters: p=12mm, d1=1.5mm, d2=1.8mm, m=0.9mm, n=1mm, w1=0.5mm, w2=2mm, infrared emissivity: 0.271 (theoretical value).

[0084] The preparation method of the infrared-radar compatible stealth skin of the present embodiment is as follows:

[0085] The preparation method of the low infrared reflection layer and the microwave absorption layer is the same, which is as follows:

[0086] S1, the polydimethylsiloxane PDMS and SE1700 curing agent are stirred uniformly at a mass ratio of 10:1 to make glue, then the glue is added dropwise into a circular silicon wafer, and the silicon wafer is placed in a spin coater to spin at 500 r / min for 10 s and then at 800 r / min for 40 s until the glue is uniformly coated on the surface of the silicon wafer, then the ITO film is uniformly pasted on the surface of the silicon wafer, and then the silicon wafer is placed in a vacuum machine for two hours, and the vacuum degree of the vacuum chamber is extracted to <3.0x10 -3 Pa, and the temperature is heated to 85℃;

[0087] S2, after the ITO film obtained in step S2 is cleaned with alcohol, it is placed in a glue coating and developing machine to spin the photoresist, and then photoetching is performed with a photoetching machine, and the exposure dose is 110 mJ / cm 2 The ITO film is placed in a tin oxide / indium tin oxide etching solution (TE-100) for wet etching, and the etching time of the ITO film with a resistance of 5Ω / sq and 80Ω / sq is 140 s and 15 s respectively, then the ITO film is cleaned with deionized water and dried, the photoresist is removed with acetone solution, and finally the ITO film is separated from the silicon wafer by placing it in an alcohol solution.

[0088] After the low infrared reflection layer 1 and the microwave absorption layer 2 are prepared, the low infrared emission layer 1, the microwave absorption layer 2 and the full reflection layer 3 are bonded in sequence.

[0089] The infrared-radar compatible stealth skin prepared in this embodiment is subjected to performance detection, and the detection results are as follows: microwave absorption rate: 9.52-24.46 GHz > 90%; actual bandwidth: 14.94 GHz; as shown in Figure 7 .

[0090] Example 2

[0091] As Figure 8As shown, the infrared-radar compatible stealth skin of the embodiment includes, from top to bottom, a low infrared emission layer 1, a microwave absorption layer 2, and a total reflection layer 3, wherein the low infrared emission layer 1 includes, from top to bottom, a first ITO layer 101, a first PET layer 102, and a first transparent layer 103, the microwave absorption layer 2 includes, from top to bottom, a second ITO layer 201, a second PET layer 202, and a second transparent layer 203, and the total reflection layer 3 includes a third ITO layer 301 and a third PET layer 302, the first ITO layer 101 is in a periodic array, the second ITO layer 201 is in a square ring arrangement and the number of square rings is 2, the material of the first transparent layer 103 is PET, the material of the second transparent layer 203 is PET, the sheet resistance of the first ITO layer 101 is 5Ω / sq, the sheet resistance of the second ITO layer 201 is 80Ω / sq, the sheet resistance of the third ITO layer 301 is 5Ω / sq, and the thicknesses of the first PET layer 102, the second PET layer 202, and the third PET layer 302 are all 0.175mm.

[0092] According to the parameterized design method for the infrared-radar compatible stealth skin, the parameters of the embodiment are designed as follows: the low infrared reflection layer 1 is: a first ITO layer 101 with a surface ratio of 81% + a first PET layer 102 with a thickness of 0.175mm + a first transparent layer 103 with a thickness of 1.5mm; the microwave absorption layer 2 is: a second ITO layer 201 with a double ring structure + a second PET layer 202 with a thickness of 0.175mm + a second transparent layer 203 with a thickness of 1.8mm; and the total reflection layer 3 is: a third ITO layer 301 + a third PET layer 302 with a thickness of 0.175mm.

[0093] Dimension parameters: p=12mm, d1=1.5mm, d2=1.8mm, m=0.9mm, n=1mm, w1=0.5mm, C=22mm, w2=2mm, infrared emissivity: 0.271(theoretical value)

[0094] The preparation method of the infrared-radar compatible stealth skin of the embodiment is as follows:

[0095] The preparation method of the low infrared reflection layer 1 is the same as that of the microwave absorption layer 2, which is as follows:

[0096] S1, uniformly stir polydimethylsiloxane PDMS and SE1700 curing agent in a mass ratio of 10:1 to make glue, then drop the glue into a circular silicon wafer, and place the silicon wafer in a spin coater to spin at 500r / min for 10s and then at 800r / min for 40s until the glue uniformly covers the surface of the silicon wafer, then uniformly paste the ITO film on the surface of the silicon wafer, and then place the silicon wafer in a vacuum machine for two hours, and the vacuum degree of the vacuum chamber is extracted to <3.0×10 -3Pa, temperature heating to 85℃;

[0097] S2, after cleaning the surface of the ITO film obtained in step S2 with alcohol, placing it in a glue coating developing machine to spin coat photoresist, continuing to use a photoetching machine to perform photoetching, with an exposure dose of 110 mJ / cm 2 Placing the ITO film in a tin oxide / indium tin oxide etching solution (TE-100) to perform wet etching, with an etching time of 140 s and 15 s for ITO films of 5 Ω / sq and 80 Ω / sq respectively, then cleaning the ITO film with deionized water and drying, continuing to remove the photoresist with an acetone solution, and finally placing it in an alcohol solution to separate it from the silicon wafer.

[0098] After preparing the low infrared reflection layer 1 and the microwave absorption layer 2, the low infrared emission layer 1, the microwave absorption layer 2 and the total reflection layer 3 are sequentially bonded.

[0099] The infrared-radar compatible stealth skin prepared in this embodiment is subjected to performance detection, and the detection results are as follows: microwave absorption rate: 8.60-26.46 GHz > 90%, actual bandwidth: 17.86 GHz; as shown in Figure 9 .

[0100] Example 3

[0101] As shown in Figure 10 , the infrared-radar compatible stealth skin of this embodiment includes, from top to bottom, a low infrared emission layer 1, a microwave absorption layer 2 and a total reflection layer 3, wherein the low infrared emission layer 1 includes, from top to bottom, a first ITO layer 101, a first PET layer 102 and a first transparent layer 103, the microwave absorption layer 2 includes, from top to bottom, a second ITO layer 201, a second PET layer 202 and a second transparent layer 203, and the total reflection layer 3 includes a third ITO layer 301 and a third PET layer 302, the first ITO layer 101 is in a periodic array, the second ITO layer 201 is arranged in a square ring shape and the number of square rings is 3, the material of the first transparent layer 103 is PET, the material of the second transparent layer 203 is PET, the sheet resistance of the first ITO layer 101 is 5 Ω / sq, the sheet resistance of the second ITO layer 201 is 80 Ω / sq, the sheet resistance of the third ITO layer 301 is 5 Ω / sq, and the thicknesses of the first PET layer 102, the second PET layer 202 and the third PET layer 302 are all 0.175 mm.

[0102] According to the parameterized design method for the infrared-radar compatible stealth skin, the parameters of the embodiment are designed as follows: the low infrared reflection layer 1 is: a first ITO layer 101 with a surface ratio of 81% + a first PET layer 102 with a thickness of 0.175 mm + a first transparent layer 103 with a thickness of 1.5 mm; the microwave absorption layer 2 is: a second ITO layer 201 with a three-ring structure + a second PET layer 202 with a thickness of 0.175 mm + a second transparent layer 203 with a thickness of 1.8 mm; the total reflection layer 3 is: a third ITO layer 301 + a third PET layer 302 with a thickness of 0.175 mm.

[0103] The size parameters are: p = 12 mm, d1 = 1.5 mm, d2 = 1.8 mm, m = 0.9 mm, n = 1 mm, w1 = 0.5 mm, C1 = 26 mm, w2 = 0.48 mm, C2 = 12.72 mm, w3 = 0.26 mm, w4 = 0.52 mm, and the infrared emissivity is 0.271 (theoretical value).

[0104] The preparation method of the embodiment for the infrared-radar compatible stealth skin is as follows:

[0105] The preparation method of the low infrared reflection layer 1 is the same as that of the microwave absorption layer 2, which is as follows:

[0106] S1, after stirring the polydimethylsiloxane PDMS and the SE1700 curing agent uniformly at a mass ratio of 10:1, a glue is prepared, then the glue is added dropwise into a circular silicon wafer, and the silicon wafer is placed in a spin coater to spin at 500 r / min for 10 s and then at 800 r / min for 40 s, until the glue uniformly covers the surface of the silicon wafer, the ITO film is uniformly pasted on the surface of the silicon wafer, then the silicon wafer is placed in a vacuum machine for two hours, and the vacuum degree of the vacuum chamber is extracted to be <3.0x10 -3 Pa, and the temperature is heated to 85℃;

[0107] S2, after the ITO film obtained in step S2 is cleaned with alcohol, the ITO film is spin coated with photoresist in a glue coating and developing machine, and photoetching is continued, and the exposure dose is 110 mJ / cm 2 The ITO film is placed in a tin oxide / indium tin oxide etching solution (TE-100) for wet etching, and the etching time of the ITO film with a resistance of 5Ω / sq and 80Ω / sq is 140 s and 15 s respectively, then the ITO film is cleaned with deionized water and dried, the photoresist is removed with acetone solution, and finally the ITO film is separated from the silicon wafer in alcohol solution.

[0108] After the low infrared reflection layer 1 and the microwave absorption layer 2 are prepared, the low infrared reflection layer 1, the microwave absorption layer 2 and the total reflection layer 3 are sequentially bonded.

[0109] The infrared-radar compatible stealth skin prepared in the embodiment is subjected to performance detection, and the detection results are as follows: microwave absorption rate: 8.75-28.19 GHz > 90%, and the actual bandwidth is 19.44 GHz; as shown in Figure 11 Figure 1, infrared stealth performance test (infrared emissivity):

[0110] It can be known from the Kirchhoff's law that the emissivity is equal to the absorption rate under the equilibrium condition. Therefore, the infrared emissivity can be calculated by measuring the transmission and reflection spectra of the structure by using a Fourier infrared spectrometer (Bruker INVENIO-S). The parameters of the low infrared emission layer of all the embodiments are the same, and therefore the infrared emissivity is the same. The experimental test results are as shown in Figure 12 Figure 2, and the average emissivity in the infrared waveband of 3-14 μm is 0.282, which is very close to the theoretical calculation 0.271 of the design method.

[0111] The structure parameters of the same position in the microwave absorption layer of all the embodiments are the same, and therefore the low-frequency absorption peak positions of all the embodiments remain consistent. The positions of the two absorption peaks of the embodiment 2 and the embodiment 3 are the same, which indicates that the parameterized design method proposed in the present application is reliable.

[0112] 2, radar stealth performance test (microwave absorption rate):

[0113] The microwave absorption characteristics of the sample are measured by using an AV3655 stealth target radar scattering cross section tester in a microwave anechoic chamber. Two pairs of wideband horn antennas with working frequencies of 2-18 GHz and 18-40 GHz are used for measurement, respectively. Each pair of transmitting and receiving horn antennas respectively acts as an electromagnetic wave transmitter and an electromagnetic wave receiver. The transmittance is almost 0 due to the existence of the bottom full reflection layer, and therefore the microwave absorption rate is directly obtained by measuring the reflectivity. The simulation results are very close to the experimental test results, which confirms the feasibility of the parameterized design method and the preparation method.

[0114] 3, visible light transmittance performance test (visible light transmittance)

[0115] The visible light transmittance is tested by using a visible light waveband ocean spectrometer in an optical darkroom. The transmittance of the single-ring, double-ring and three-ring stealth skin samples in the visible light waveband of 400-800 nm reaches 49%, 51% and 47%, respectively, as shown in Figure 13 Figure 3.

[0116] Although the present application discloses the above, the protection scope of the present application is not limited to this. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and these changes and modifications shall fall within the protection scope of the present application.

Claims

1. An infrared-radar compatible stealth skin, characterized in that, It comprises low infrared emission layer (1), microwave absorption layer (2) and total reflection layer (3) arranged in turn from top to bottom, wherein the low infrared emission layer (1) comprises first ITO layer (101), first PET layer (102) and first transparent layer (103) arranged in turn from top to bottom, the microwave absorption layer (2) comprises second ITO layer (201), second PET layer (202) and second transparent layer (203) arranged in turn from top to bottom, and the total reflection layer (3) comprises third ITO layer (301) and third PET layer (302), the first ITO layer (101) is arranged in a periodic array, and the second ITO layer (201) is arranged in a square ring shape and the number of square rings is 1, 2 or 3. The parameterized design method of the infrared-radar compatible stealth skin comprises the following steps: S1, obtaining the infrared emissivity and the microwave absorption bandwidth; S2, obtaining the surface ratio corresponding to the second ITO layer (201) according to the numerical value of the infrared emissivity, and obtaining the width corresponding to the second ITO layer (201) according to the frequency range of the microwave absorption bandwidth; S3, obtaining the low-frequency absorption peak position according to the low-frequency range of the microwave absorption bandwidth, and obtaining the total thickness of the first transparent layer (103) and the second transparent layer (203) according to the low-frequency absorption peak position; S4, obtaining the size parameters of the square ring in the microwave absorption layer (2) according to the high-frequency absorption peak position in the frequency range of the microwave absorption bandwidth for verifying the target parameter requirements; In the step S2, the processing formula of the surface ratio corresponding to the first ITO layer (101) is as follows: ； wherein, the infrared emissivity of the stealth skin, and respectively the infrared emissivity of the first ITO layer (101) and the first PET layer (102), is the surface ratio of the first ITO layer (101); the processing formula of the corresponding width of the first ITO layer (101) is as follows: ； wherein f is the resonant frequency, c is the speed of light in a vacuum, n is the refractive index of the substrate material, w is the width of the ITO patch; The thickness of the medium in the step S3 d is determined by the position of the low-frequency absorption peak, and the correspondence relationship is as follows: ； wherein d is the total thickness of the first transparent layer (103) and the second transparent layer (203), n is the impact factor, u is the wave velocity of the electromagnetic wave in the medium, f is the center frequency of the low-frequency absorption peak.

2. The infrared-radar compatible stealth skin of claim 1, wherein, The sheet resistance of the first ITO layer (101) is 5-10Ω / sq, the sheet resistance of the second ITO layer (201) is 70-100Ω / sq, and the sheet resistance of the third ITO layer (301) is <8Ω / sq.

3. The infrared-radar compatible stealth skin of claim 1, wherein, The thickness of the first PET layer (102), the second PET layer (202) and the third PET layer (302) is all <0.3mm.

4. A method for producing an infrared-radar compatible stealth skin according to any one of claims 1 to 3, characterized in that, The preparation method comprises preparing the low infrared emission layer (1), the microwave absorption layer (2) and the total reflection layer (3) respectively, and then bonding the low infrared emission layer (1), the microwave absorption layer (2) and the total reflection layer (3) in turn, the preparation method of the low infrared emission layer (1) is the same as that of the microwave absorption layer (2), and specifically comprises the following steps: S1, drop the glue into the circular silicon wafer, place the silicon wafer in the spin coater for spin coating treatment, then paste the ITO film on the surface of the silicon wafer, and then place the silicon wafer in the vacuum chamber with the vacuum degree < 3.0x10 -3 Pa, heat and keep warm in the vacuum chamber; S2, placing the ITO film obtained in step S1 in a glue coating and developing machine to spin coating photoresist, then using a photoetching machine for photoetching treatment, then placing in etching solution for wet etching, then removing the photoresist with acetone solution, and finally separating from the silicon wafer by placing in alcohol solution.

5. The method of producing an infrared-radar compatible stealth skin of claim 4, wherein, In the step S1, the components of the glue are polydimethylsiloxane and SE1700 curing agent, and the mass ratio of polydimethylsiloxane and SE1700 curing agent is 10:1; and / or, The spin coating step is as follows: first spin coating at 500r / min for 10s, and then spin coating at 800r / min for 40s; and / or, The temperature of the temperature rise is 85℃, and the holding time is 2h.

6. The method of making an infrared-radar stealth compatible skin of claim 4, wherein, In the step S2, in the photolithography process, the exposure dose is 110 mJ / cm 2 ; and / or, The etching solution is TE-100; and / or, The etching time of the ITO layer with 5 Ω / sq is 140 s, and the etching time of the ITO layer with 80 Ω / sq is 15 s.

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