Skin-like visible-infrared composite thin film materials, their preparation methods and applications

Abstract

This invention discloses a skin-like visible-infrared composite thin film material, its preparation method, and its applications. The composite thin film material includes an elastomer layer, an infrared functional layer, and a dielectric layer; the infrared functional layer and the dielectric layer form a structural color; the infrared functional layer has an irregular micro / nano structure, which changes with the stretching or rebounding contraction of the elastomer layer to adjust the infrared emissivity. This invention utilizes an elastomer, pre-stretching it, and then forming a Fabry-Perot optical resonator using convenient film-forming methods such as magnetron sputtering, spraying, spin coating, and uniform coating, thereby generating a structural color. It also reveals that the infrared emissivity can be dynamically changed by stretching or releasing the elastomer, while maintaining the structural color unchanged, achieving decoupled control. This control method is convenient, efficient, and low-cost, making it highly beneficial for the widespread application of infrared functional materials.

Description

Technical Field

[0001] This invention relates to the field of infrared functional materials technology, and in particular to a skin-like visible-infrared composite thin film material, its preparation method and application. Background Technology

[0002] In practical applications, the Earth's surface light and heat environment will change significantly with day and night and seasons, requiring corresponding light / heat control technologies to adapt and achieve active switching. The widespread application of infrared heating technology with independent light and heat control across a wide wavelength range, and the application of high-emissivity infrared radiation materials in fields such as biomimetic camouflage and radiative cooling, present new opportunities when combined with dynamic spectral control of visible and mid-infrared light.

[0003] Operating at seemingly unrelated wavelengths, such as visible light and mid-infrared, which differ by an order of magnitude, allows for spectral decoupling. In principle, manipulating the spatial distribution of light and heat on demand requires compatibility between frequency band selection and dynamic control on the same surface; wide-spectrum decoupling is key. These multispectral operations, such as thermal control, radiative cooling, and adaptive camouflage, can be used to hide and encode different wavelength information in the visible and mid-infrared ranges, achieving unique display effects, anti-counterfeiting effects, and more.

[0004] Traditional multicolor surface technologies often utilize a variety of multicolored coatings, offering strong spectral selectivity. However, frequent coating changes are necessary for different colors, increasing operating costs. These frequent changes are time-consuming and labor-intensive, and lack active control capabilities. Traditional technologies that achieve multicolor surfaces by constructing structural colors often require precise optical etching, resulting in extremely high costs. Traditional infrared-controlled visible colors are mostly transparent or single-color, with complex structures. Electrochromism offers dynamic control capabilities, but its spectral selectivity is limited and dependent on device fabrication, cost, and large-area application.

[0005] However, existing infrared modulation technology and color change are difficult to control independently, and there is currently no ideal solution. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a skin-like visible-infrared composite thin film material, its preparation method, and its applications.

[0007] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0008] In a first aspect, the present invention provides a skin-like visible-infrared composite thin film material, which includes an elastomer layer, an infrared functional layer and a dielectric layer stacked sequentially.

[0009] The elastomer layer has tensile-rebound properties along the planar direction, the infrared functional layer is made of a metallic element, and the dielectric layer is made of an oxide.

[0010] The infrared functional layer and the dielectric layer constitute a Fabry-Perot optical resonant cavity to form structural color;

[0011] In its natural state, the infrared functional layer has an irregular micro-nano structure, and the morphology and / or size of the irregular micro-nano structure changes with the stretching or rebounding contraction of the elastomer layer to adjust the infrared emissivity of the skin-like visible-infrared composite film material.

[0012] Secondly, the present invention also provides a method for preparing a skin-like visible-infrared composite thin film material, comprising:

[0013] The elastomer layer is pre-stretched;

[0014] While maintaining a stretched state, an infrared functional layer is deposited on the surface of the elastomer layer to form a layer.

[0015] The stretched state is removed, causing the elastomer layer to contract and spring back, so that at least the infrared functional layer forms an irregular micro / nano structure;

[0016] And the step of depositing a dielectric layer on the surface of the infrared functional layer.

[0017] Thirdly, the present invention also provides the application of the above-mentioned skin-like visible-infrared composite thin film material in the fields of surface decoration or optics.

[0018] Fourthly, the present invention also provides an infrared emissivity adjustment method, comprising:

[0019] Provide the above-mentioned skin-like visible-infrared composite thin film material;

[0020] The skin-like visible-infrared composite film material is stretched or spring-loaded to change the morphology and / or size of the irregular micro-nano structures in the skin-like visible-infrared composite film material, so as to adjust the infrared emissivity of the skin-like visible-infrared composite film material, while keeping the color of the skin-like visible-infrared composite film material unchanged in the visible light band.

[0021] Based on the above technical solution, compared with the prior art, the beneficial effects of the present invention include at least the following:

[0022] The present invention utilizes an elastomer, which is pre-stretched and then formed into a Fabry-Perot optical resonant cavity using convenient film-forming methods such as magnetron sputtering, spraying, spin coating, and uniform coating, thereby generating structural color. Furthermore, it has been discovered that the infrared emissivity can be dynamically changed by stretching or releasing the contracted elastomer, while maintaining the structural color unchanged, achieving decoupled control. This control method is convenient, efficient, and inexpensive, making it highly beneficial for the widespread application of infrared functional materials.

[0023] The above description is merely an overview of the technical solution of the present invention. In order to enable those skilled in the art to better understand the technical means of this application and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described below in conjunction with detailed drawings. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a skin-like visible-infrared composite thin film material provided in a typical embodiment of the present invention;

[0025] Figure 2 These are colorful physical images of a skin-like visible-infrared composite thin film material provided in a typical embodiment of the present invention;

[0026] Figure 3 These are photographs of a skin-like visible-infrared composite thin film material under different stretching rates, provided in a typical embodiment of the present invention.

[0027] Figure 4 This is an infrared camera image of a skin-like visible-infrared composite thin film material under different stretching rates, provided in a typical embodiment of the present invention.

[0028] Figure 5 This is an infrared emission spectrum test image of a skin-like visible-infrared composite thin film material before and after stretching, provided in a typical embodiment of the present invention. Detailed Implementation

[0029] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The following will further explain and illustrate this technical solution, its implementation process, and its principles.

[0030] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0031] like Figure 1As shown, this embodiment of the invention provides a skin-like visible-infrared composite thin film material, which structurally includes an elastomer layer, an infrared functional layer, and a dielectric layer stacked sequentially; the elastomer layer has tensile-rebound characteristics along the planar direction, the infrared functional layer is made of a metallic element, and the dielectric layer is made of an oxide.

[0032] Functionally, the infrared functional layer and the dielectric layer constitute a Fabry-Perot optical resonant cavity to form structural color; in its natural state (natural state refers to the initial state when the composite film material is not stretched in any way), the infrared functional layer has an irregular micro-nano structure, and the irregular micro-nano structure changes in morphology and / or size as the elastomer layer stretches or rebounds to adjust the infrared emissivity of the skin-like visible-infrared composite film material.

[0033] Regarding the specific form of the irregular micro / nano structure, in some embodiments, the elongation at break in the planar direction of the elastomer layer is greater than the elongation at break of the infrared functional layer and the dielectric layer; the irregular micro / nano structure includes wrinkles and / or microcracks generated by the tensile expansion or springback contraction of the elastomer layer.

[0034] Combined with the preparation method described below, the skin-like visible-infrared composite thin film material provided by this invention, due to pre-stretch deposition, will develop some wrinkles in the film layer under natural conditions, forming an irregular micro-nano structure. When the composite thin film material is stretched, the spacing between the wrinkle protrusions may increase, and the curvature or height of the wrinkles may also change accordingly. Furthermore, when stretched to a certain extent, the wrinkling phenomenon may even nearly disappear. In addition, when stretched excessively (typically, for example, above the pre-stretch ratio during deposition), microcracks may appear in the deposited film layer. It is evident that the morphology and size of the irregular micro-nano structure will change under different stretching states. Based on these changes, its infrared emissivity can be controlled. Moreover, the inventors of this invention have discovered that while controlling the infrared emissivity, the structural color of the composite thin film material does not undergo significant color change, achieving the purpose of decoupled control.

[0035] The above technical solution belongs to the field of infrared functional materials, and particularly relates to devices and methods for long-wave infrared spectral modulation. As a specific example, the skin-like visible-infrared composite thin film material comprises an elastomer layer and a Fabry-Perot optical resonator layer. This Fabry-Perot optical resonator layer includes an infrared functional layer and a dielectric layer. The elastomer layer has high elasticity, can be stretched, and rebounds after release. The infrared functional layer and the dielectric layer form optical interference, constituting the Fabry-Perot optical resonator, producing color. The thickness of the infrared functional layer and the dielectric layer is below the infrared emission wavelength of the infrared functional layer to avoid shielding infrared emission. The specific infrared emission wavelength depends on the selected material and process, and is not limited to a specific value.

[0036] Traditional biomimetic materials primarily control the spectrum in the infrared band, exhibiting mainly transparency or whiteness in the visible light range, significantly limiting their applications. The main difference between this invention and some traditional solutions lies in the ability to achieve customizable colors in the visible light spectrum while maintaining the visible light color unchanged before and after infrared modulation. This achieves biomimetic color-changing with unchanged visible light and dynamic infrared modulation. The key features are: 1) using an infrared functional layer material and a dielectric layer to achieve multi-color electrochromism through thin-film interference; 2) in addition to the visible light band, the use of an infrared functional layer material also enables dynamic infrared spectrum modulation, whereas traditional solutions using metal layers as conductive layers cannot achieve infrared modulation.

[0037] In many existing related technologies, infrared modulation is only concentrated in the near-infrared band (0.5-2.5 µm), which cannot cover a wide spectrum and cannot achieve vibrant visible colors. Furthermore, it is worth noting that, in order to fully realize dynamic infrared modulation without affecting visible colors, this invention selects a nanoscale, non-destructive infrared functional layer, which will not affect infrared performance. In a specific implementation, the visible light color-changing layer consists of a metallic infrared functional layer and an oxide dielectric layer, respectively. The wide-spectrum electrochromic layers form an optical interference effect, achieving a wide color gamut with multiple colors, including yellow, orange, magenta, purple, blue, cyan, and green.

[0038] When in use, whether stretched or unstretched, the color and brightness of the visible color-changing layer are not obscured by other structural layers and can be directly observed, thus achieving a very good visual effect. However, the size and morphology of the irregular micro-nano structure that affects the infrared emissivity can be affected by stretching and springback, which in turn causes the infrared emissivity to change accordingly, thus achieving decoupled regulation.

[0039] Regarding specific dimensional characteristics, in some embodiments, the thickness of the elastomeric layer is greater than 0 and less than or equal to 1 mm. Furthermore, the aspect ratio is typically 2:1 or higher to facilitate stretching and springback; however, this is not a limitation, and other shapes can also be stretched and springbacked in the same way.

[0040] In some embodiments, the elastomer layer has an elongation at break of more than 30% in the planar direction.

[0041] In some implementations, the total thickness of the infrared functional layer and the dielectric layer is greater than 100 nm. Generally, the visible light color is changed by altering the thickness of the dielectric layer, resulting in different structural colors. This can be adjusted based on specific needs, and even different thicknesses can be deposited in different regions to create multicolor camouflage.

[0042] Regarding the materials of each layer, in some embodiments, the elastomer layer is made of any one or a combination of two or more of PDMS, Ecoflex, acrylate film, ACM, ADE, and LCE. PDMS is further preferred. However, it is not limited to this; other materials with the above characteristics can still achieve the same effect, as long as they can ensure good bonding strength, tensile strength, and resilience.

[0043] In some embodiments, the material of the infrared functional layer includes any one or a combination of two or more of W, Al, Ag, Au, and Ga, with W being more preferred. However, it is not limited to this; other metals with the above characteristics can still perform the same function.

[0044] In some embodiments, the dielectric layer is made of any one or a combination of two or more of WO3, TiO2, ITO, and SiO2, with WO3 being more preferred. However, it is not limited to this; other oxides with the above characteristics can still perform the same function.

[0045] Based on the above structural and functional characteristics, in some embodiments, the infrared emissivity of the skin-like visible-infrared composite thin film material is adjusted in the band of 3-15μm, with an adjustment range of more than 30%.

[0046] To obtain the aforementioned skin-like visible-infrared composite thin film material, a second aspect of the present invention also provides a method for preparing the skin-like visible-infrared composite thin film material, which includes the following steps:

[0047] The elastomer layer is pre-stretched;

[0048] While maintaining a stretched state, an infrared functional layer is deposited on the surface of the elastomer layer to form a layer.

[0049] The stretched state is removed, causing the elastomer layer to contract and spring back, so that at least the infrared functional layer forms an irregular micro / nano structure;

[0050] And the step of depositing a dielectric layer on the surface of the infrared functional layer.

[0051] It should be noted that, in the above steps, the timing of the formation of the dielectric layer can be as follows: after the infrared functional layer is formed while maintaining the stretched state, the dielectric layer is deposited immediately and then the stretched state is removed; alternatively, the dielectric layer can be deposited after the stretched state is removed (or even during the process of slowly removing the stretched state). Different deposition timings will not have a very significant impact on the formation of a material structure with obvious infrared emissivity regulation, and the present invention does not impose specific limitations on this.

[0052] In some embodiments, the pre-stretching elongation is above 30%. Generally, it is preferred to be around 60%. Of course, the upper limit of the elongation is usually limited by the elongation at break of the material itself, or by the elongation at which it can undergo elastic deformation and rebound. For example, some polymer materials do not break after exceeding a certain elongation, but lose their resilience.

[0053] In some embodiments, the deposition method of the infrared functional layer and / or dielectric layer includes any one or a combination of two or more of spin coating, spray coating, blade coating, brush coating, magnetron sputtering, and deposition.

[0054] Based on the above technical solutions, this invention achieves infrared modulation by constructing microstructures on the surface and realizes visible multicolor by building a surface optical interference coating. The preferred method is magnetron sputtering. While some existing technologies utilize surface wrinkles for infrared biomimetic modulation, these methods primarily aim to improve infrared performance, such as enhancing modulation amplitude, and are mainly for functional purposes rather than optical purposes of constructing multicolor surfaces. In contrast to traditional infrared biomimetic methods, the method provided by this invention can combine visible color with infrared modulation and achieve multiple decoupled modulation. Furthermore, traditional biomimetic infrared methods generally lack the ability to achieve visible camouflage, while this invention combines the infrared modulation principles of Fabry-Perot resonators (optical resonance principle) and micro / nano structures. Its advantages include simple and controllable methods, representing a completely novel technical approach.

[0055] From one perspective, this invention utilizes the construction of multicolored materials; from another perspective, it utilizes dynamic biomimetic control of infrared radiation to achieve the preparation of multicolored thin film materials with adjustable infrared characteristics, resembling biological skin, without modifying the materials.

[0056] Correspondingly, a third aspect of the present invention also provides the application of the skin-like visible-infrared composite thin film material provided in any of the above embodiments in the fields of surface decoration or optics.

[0057] As a specific application of the above, a fourth aspect of the present invention also provides an infrared emissivity adjustment method, which includes the following steps:

[0058] Provide a skin-like visible-infrared composite thin film material according to any of the above embodiments;

[0059] The skin-like visible-infrared composite film material is stretched or spring-loaded to change the morphology and / or size of the irregular micro-nano structures in the skin-like visible-infrared composite film material, so as to adjust the infrared emissivity of the skin-like visible-infrared composite film material, while keeping the color of the skin-like visible-infrared composite film material unchanged in the visible light band.

[0060] The technical solution of the present invention will be further described in detail below through several embodiments and in conjunction with the accompanying drawings. However, the selected embodiments are only for illustrating the present invention and do not limit the scope of the present invention.

[0061] Example 1

[0062] This embodiment provides a biomimetic photonic skin structure with decoupled control of visible light / thermal infrared spectra, such as... Figure 1 As shown, it includes, from top to bottom, a dielectric layer, an infrared functional layer, and an elastomer layer.

[0063] The elastomer layer is made of PDMS with a thickness of about 1 mm, a width of 2 cm and a length of 6 cm. The curing agent ratio during the production of this PDMS is 10:1, which gives it certain elasticity and good resilience.

[0064] The infrared functional layer is made of 100nm thick W, and the dielectric layer is made of WO3.

[0065] The elongation rate is set to 30%.

[0066] The overall thickness of this broadband decoupled independently modulated film is 1 mm, and it can independently modulate well in the mid-infrared band.

[0067] The method for preparing this broadband decoupled independently modulated thin film includes:

[0068] S1. Pre-stretch the elastomer layer.

[0069] S2. Perform magnetron sputtering on the pre-stretched sample. Set the power supply and current of the magnetron sputtering instrument to sputter 100nm W and 233nm WO3. The sample will be green at this time.

[0070] S3. Remove the pre-stretching force from the sputtered sample to obtain an irregular microstructure on the surface. Observe the size and shape of the microstructure under SEM to complete the fabrication.

[0071] The color of a sample can be altered by changing the thickness of the tungsten oxide, and the sample can achieve the following: Figure 2 The image shows multiple colors, which can be further patterned. Furthermore, a photograph of a broadband decoupled independently controllable thin film fabricated in this embodiment is shown below. Figure 3As shown, its color is green before stretching. Applying the same force to both ends of the sample and adjusting the rate of force application can change the infrared emissivity of the material as follows. Figure 4 and Figure 5 As shown, the visible color can remain green, and the emissivity changes continuously with the change in stretching ratio.

[0072] Example 2

[0073] The large-area flexible broadband decoupled independent controllable thin film provided in this embodiment is similar to that in Embodiment 1, including a dielectric layer, a metal layer, and an elastomer layer arranged sequentially from top to bottom.

[0074] The elastomer layer is made of PDMS with a thickness of about 1 mm. The curing agent ratio during the production of PDMS is 30:1, which has good elasticity and good resilience.

[0075] The infrared functional layer is made of 100nm thick W, and the dielectric layer is made of WO3.

[0076] The elongation rate is set to 50%.

[0077] The overall thickness of this wide-spectrum decoupled independent modulation device is 1 mm, and it can independently and with good modulation amplitude in the mid-infrared band.

[0078] The large-area flexible broadband decoupled independent controllable thin film prepared in this embodiment has similar effects to that in Example 1.

[0079] Example 3

[0080] The ultrathin broadband decoupled independent control film provided in this embodiment is similar to that in Embodiment 1, including a dielectric layer, an infrared functional layer, and an elastomer layer arranged sequentially from top to bottom.

[0081] The elastomer layer is made of PDMS with a thickness of about 100 μm. The curing agent ratio during the fabrication of this PDMS is 10:1, which gives it good elasticity and good resilience.

[0082] The infrared functional layer is made of 100nm thick W, and the dielectric layer is made of WO3.

[0083] The elongation rate is set to 150%.

[0084] The overall thickness of this wide-spectrum decoupled independent modulation device is 100 μm, and it can independently and with good modulation amplitude in the mid-infrared band.

[0085] Example 4

[0086] This embodiment provides a broadband decoupled independent controllable thin film, similar to that in Embodiment 1, except that the metal layer is changed to Al.

[0087] Al also exhibits high infrared reflectivity, with an infrared reflectance greater than W. Therefore, the reflectance of this thin film before and after adjustment is generally higher than that of Example 1, while its visible light saturation decreases to some extent. This implementation method is also applicable to Examples 2 and 3.

[0088] Example 5

[0089] This embodiment provides a broadband decoupled independent controllable thin film, similar to Embodiment 1, except that an additional 10nm metal layer, such as W, Ti, etc., is added on top of the dielectric layer, but is not limited to this.

[0090] The added metal layer can improve the color saturation of the upper surface of the device, and the 10nm metal layer is insufficient to affect long-wave infrared modulation. This embodiment is also applicable to Embodiments 2, 3, and 4.

[0091] Example 6

[0092] This embodiment provides a broadband decoupled independent controllable thin film, similar to that in Embodiment 3, except that the elastomer layer is changed to a 100 μm thick Ecoflex.

[0093] Green films can still be obtained, and the long-wave infrared emissivity is adjustable.

[0094] Comparative Example 1

[0095] This comparative example is largely the same as Example 1, with the main difference being:

[0096] Set the elongation rate below 30%, specifically 15%.

[0097] Due to insufficient stretching, the resulting microstructure has a low size and density, and the resulting thin film material can only exhibit a low infrared modulation amplitude. After testing, its infrared modulation amplitude is less than 0.15%, which is significantly lower than the above implementation case. In practical applications, it is difficult to meet the needs of large-scale adjustment of infrared emissivity.

[0098] Based on the above embodiments and comparative examples, it is clear that the present invention, provided in the embodiments of the present invention, uses an elastomer, which is pre-stretched and then formed into a Fabry-Perot optical resonant cavity using convenient film-forming methods such as magnetron sputtering, spraying, spin coating, uniform coating, and electrodeposition, thereby generating structural color. At the same time, it was found that the infrared emissivity can be dynamically changed by stretching or releasing the contracted elastomer, and the color of the structural color can remain unchanged while changing the infrared emissivity, thus achieving decoupled control. This control method is convenient, efficient, and low in cost, which is very beneficial to the widespread application of infrared functional materials.

[0099] It should be understood that the above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A skin-like visible-infrared composite thin film material, characterized in that, It includes an elastomer layer, an infrared functional layer, and a dielectric layer stacked sequentially. The thickness of the elastomer layer is greater than 0 and less than or equal to 1 mm, and it has tensile-spring properties along the planar direction, with an elongation at break of more than 30% in the planar direction; the material of the infrared functional layer includes a metallic element, the material of the dielectric layer includes an oxide, the total thickness of the infrared functional layer and the dielectric layer is more than 100 nm, the material of the infrared functional layer includes any one or a combination of two or more of W, Al, Ag, Au, and Ga, and the material of the dielectric layer includes any one or a combination of two or more of WO3, TiO2, ITO, and SiO2; The infrared functional layer and the dielectric layer constitute a Fabry-Perot optical resonant cavity to form structural color; In its natural state, the infrared functional layer has an irregular micro-nano structure, which includes wrinkles and / or microcracks generated by the stretching, expansion or rebound contraction of the elastomer layer. The irregular micro-nano structure changes its morphology and / or size with the stretching, expansion or rebound contraction of the elastomer layer to adjust the infrared emissivity of the skin-like visible-infrared composite film material and keep the color of the skin-like visible-infrared composite film material unchanged in the visible light band.

2. The skin-like visible-infrared composite thin film material according to claim 1, characterized in that, The elongation at break in the planar direction of the elastomer layer is greater than that of the infrared functional layer and the dielectric layer.

3. The skin-like visible-infrared composite thin film material according to claim 1, characterized in that, The material of the elastomer layer includes any one or a combination of two or more of PDMS, Ecoflex, ADE, and LCE.

4. The skin-like visible-infrared composite thin film material according to claim 1, characterized in that, The infrared emissivity of the skin-like visible-infrared composite thin film material can be adjusted in the 3-15μm band, with an adjustment range of over 30%.

5. The application of the skin-like visible-infrared composite thin film material according to any one of claims 1-4 in the fields of surface decoration or optics.

6. A method for preparing a skin-like visible-infrared composite thin film material according to any one of claims 1-4, characterized in that, include: The elastomer layer is pre-stretched; While maintaining a stretched state, an infrared functional layer is deposited on the surface of the elastomer layer to form a layer. The stretched state is removed, causing the elastomer layer to contract and spring back, so that at least the infrared functional layer forms an irregular micro / nano structure; And the step of depositing a dielectric layer on the surface of the infrared functional layer.

7. The preparation method according to claim 6, characterized in that, The pre-stretched elongation rate is above 30%.

8. The preparation method according to claim 6, characterized in that, The deposition method of the infrared functional layer and / or dielectric layer includes any one or a combination of two or more of spin coating, spray coating, blade coating, brush coating, magnetron sputtering, and electrodeposition.

9. A method for adjusting infrared emissivity, characterized in that, include: Provide a skin-like visible-infrared composite thin film material as described in any one of claims 1-4; The skin-like visible-infrared composite film material is stretched or spring-loaded to change the morphology and / or size of the irregular micro-nano structures in the skin-like visible-infrared composite film material, so as to adjust the infrared emissivity of the skin-like visible-infrared composite film material, while keeping the color of the skin-like visible-infrared composite film material unchanged in the visible light band.

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