A structural color device and its fabrication method

Abstract

This invention discloses a structural color device and its fabrication method. The device comprises a substrate layer and a structural layer disposed on the substrate layer. The structural layer has patterned grooves, each groove containing at least one dense layer, which is a metal layer and / or a dielectric layer. The fabrication method includes: first, coating an adhesive layer onto the substrate layer; then, using a pre-made patterned mold to imprint and cure the adhesive layer, forming a structural layer with grooves and a platform; subsequently, setting a barrier layer on the platform surface and a dense layer on the structural layer; finally, removing all material from the platform to form the structural color device. This invention enables in-situ densification and performance optimization of the filling material within the grooves under mild conditions. By combining with a microlens array, it forms a colored light field levitation imaging, improving color saturation and significantly reducing fabrication costs.

Description

[0001] This invention is a divisional application of application number 202610199233.1 filed on February 11, 2026, entitled "A Micro / Nano Functional Device and Its Fabrication Method". Technical Field

[0002] This application relates to the field of optoelectronic devices, and more particularly to a structural color device and its fabrication method. Background Technology

[0003] With the integration and industrial upgrading of technologies in display imaging and surface decoration, the demand for functional surface devices with precise microstructures is showing a trend towards diversification and high performance. Typical examples of such devices include structural color surfaces used to present dynamic optical effects, decorative films, and optical anti-counterfeiting elements. Their functionality increasingly relies on constructing precise micro-nano structures on the surface of transparent or translucent substrates, and generating rich colors and optical features through the light interference, diffraction, and scattering effects of the structure itself.

[0004] Currently, higher demands are being placed on color saturation, angular color variation effects, and environmental adaptability in decorative, packaging, and high-end color display applications. However, existing mainstream technologies still primarily use pigments or dyes as color-developing media, which has the following main shortcomings: First, the amount of pigment used is relatively large. To obtain sufficient color concentration and hiding power, thicker coatings or high-concentration additives are often required, which not only increases material costs but also results in a larger overall film thickness, affecting the flexibility of subsequent processing. Second, the manufacturing cost is high. The synthesis and dispersion processes of fine pigments are complex and require precise coating or printing equipment. In addition, the pigments themselves are expensive, resulting in high overall manufacturing costs. Third, the imaging methods are limited. Existing technologies are often limited to planar imaging, making it difficult to achieve continuous and uniform structural color presentation on curved or three-dimensional surfaces. Furthermore, the imaging clarity of different areas in light field imaging or microstructure color development is insufficient. Especially in application scenarios involving multi-area and multi-angle color control, problems such as edge blurring, color crosstalk, or excessive viewing angle dependence are prone to occur, failing to meet the requirements for high-resolution, high-sharpness three-dimensional pattern color display.

[0005] Furthermore, existing pigment-based methods face inherent limitations in achieving a synergistic effect of multiple optical indicators such as "high transparency, high color rendering, and high concealment"—the light scattering effect of pigment particles often reduces transparency, while thinning the coating leads to a decrease in color saturation. Therefore, how to achieve low-volume, low-cost, and high-definition structured color devices through optimized microstructure design and fabrication processes while reducing or even eliminating pigment dependence has become a pressing technical problem to be solved in this field. Summary of the Invention

[0006] Therefore, it is necessary to provide a structural color device and its fabrication method to address issues such as how to reduce pigment usage, lower preparation costs, and achieve high-quality imaging.

[0007] A structural color device includes: a substrate layer and a structural layer disposed on the substrate layer, wherein the structural layer has patterned grooves, and the grooves include at least one dense layer, wherein the dense layer is a metal layer and / or a dielectric layer.

[0008] In one specific embodiment, the material of the metal layer includes one or more of aluminum, copper, nickel, chromium, and silver, and the thickness of the metal layer ranges from 5 nm to 2 μm.

[0009] In one specific embodiment, the dielectric layer is a metal oxide, and the thickness of the dielectric layer ranges from 50 nm to 1 μm.

[0010] In one specific embodiment, a light-absorbing layer adjacent to the dense layer is formed on the structural layer. The light-absorbing layer is conformal to the dense layer. The light-absorbing layer is made of carbon nanoparticles or pigment particles, and the thickness of the light-absorbing layer ranges from 10 nm to 500 nm.

[0011] In one specific embodiment, a microlens array layer is provided on the substrate and on the opposite side of the structural layer. The microlens array layer includes a plurality of microlenses, each corresponding to a groove. When the groove is on the focal plane of the microlens, a moiré magnified image is formed; when the groove is outside the focal plane of the microlens, a stereoscopic light field image is formed.

[0012] In one specific embodiment, the depth of the groove ranges from 2μm to 10μm, and the width of the groove ranges from 200nm to 10μm.

[0013] In one specific embodiment, a method for fabricating a structural color device includes the following steps: S1: Provide a substrate layer, and apply an adhesive layer onto the substrate layer; S2: Using a pre-made patterned mold, an imprint is made on the adhesive layer, and after the adhesive layer is cured, a structural layer with patterned grooves and platforms is formed; S3: A barrier layer is provided on the surface of the platform, and a dense layer is provided on the structural layer; S4: Remove all material from the platform to form a structural color device.

[0014] In one specific embodiment, in step S3, a water-based material and / or an oil-based material is applied to the surface of the platform by contact coating to form the barrier layer. The thickness of the barrier layer ranges from 10 nm to 500 nm, and the thickness of the barrier layer is less than the thickness of the structural layer.

[0015] In one specific embodiment, in step S3, a metal material is deposited using a vapor deposition or sputtering process. The metal material includes one or more of aluminum, copper, nickel, chromium, and silver, which are then deposited onto the barrier layer and within the groove to form the dense layer.

[0016] In one specific embodiment, in step S3, metal oxide is deposited by vapor deposition or sputtering to adhere to the barrier layer and the groove to form the dense layer.

[0017] In one specific embodiment, in step S3, before or after the formation of the dense layer, a light-absorbing layer adjacent to the dense layer is provided in the groove.

[0018] In one specific embodiment, in step S4, all materials on the platform are removed using one or more of the following processes: physical mechanical polishing, chemical mechanical polishing, and adhesive transfer.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By employing a contact coating method to form a barrier layer on the platform surface, ensuring its non-flowability on the structural layer surface, and avoiding residual barrier layer material within the patterned grooves, a dense layer is prepared using a combination of processes such as vapor deposition and sputtering. This results in a strong adhesion of the dense layer within the patterned grooves, while the platform, due to the weak adhesion of the barrier layer and the small amount of deposited dense layer material, and the low adhesion between the barrier layer and the structural layer, facilitates the removal of all material from the platform in subsequent processes. The entire process can efficiently achieve in-situ densification and performance optimization of the filling material within the grooves under mild conditions without the need for high-temperature sintering, significantly simplifying the process flow, reducing stringent limitations on equipment and substrates, and improving the compatibility and economy of the production process.

[0020] 2. This invention allows for the design of grooves with various linewidths and depths to meet specific needs. Combined with a microlens array, these grooves create a suspended color light field imaging system. Furthermore, since the dense layer or light-absorbing layer within the groove does not need to be completely filled, the amount of raw materials used is reduced, thus lowering manufacturing costs.

[0021] 3. When the dense layer is a metal layer, the reflective properties of metal enhance the color saturation of the light field levitation imaging, resulting in vibrant colors and a metallic texture. At the same time, since the grooves correspond one-to-one with the microlens array, the imaging clarity of different areas of the light field imaging remains consistent, eliminating the need for repeated registration and simplifying the fabrication process.

[0022] 4. When removing all materials on the platform using physical / chemical mechanical polishing or adhesive transfer, the dense layer and light-absorbing layer materials can be recycled and reused, achieving both environmental benefits and resource conservation advantages. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the cross-sectional structure of a micro / nano functional device.

[0025] Figure 2 A schematic diagram of the cross-sectional structure of a micro / nano functional device.

[0026] Figure 3 A schematic diagram of the cross-sectional structure of a micro / nano functional device.

[0027] Figure 4 A schematic diagram of the cross-sectional structure of a micro / nano functional device.

[0028] Figure 5 Schematic diagram of the fabrication process for micro / nano functional devices.

[0029] Figure 6 Schematic diagram of the fabrication process for micro / nano functional devices.

[0030] Figure 7 Schematic diagram of the fabrication process for micro / nano functional devices.

[0031] Figure 8 A schematic diagram of barrier layer fabrication in the fabrication of micro / nano functional devices.

[0032] Figure 9 A schematic diagram of barrier layer fabrication in the fabrication of micro / nano functional devices.

[0033] Figure 10 Three-dimensional topographic image of the dense layer in the patterned grooves.

[0034] Figure 11 Schematic diagram of the fabrication process for micro / nano functional devices.

[0035] Figure 12 Schematic diagram of the fabrication process for micro / nano functional devices.

[0036] In the diagram: 1. Substrate layer; 2. Structural layer; 20. Adhesive layer; 21. Groove; 22. Platform; 3. Dense layer; 31. First dense layer; 32. Second dense layer; 4. Light-absorbing layer; 5. Barrier layer; 6. Gravure; 7. Rubber roller; 8. Guide roller; 9. Cooling roller. Detailed Implementation

[0037] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. Based on the description of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0038] Unless otherwise explicitly specified and limited, the terms "setup," "installation," and "connection" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of these terms based on the specific circumstances.

[0039] The terms “upper,” “lower,” “left,” “right,” “front,” “back,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0040] The terms “first,” “second,” “third,” etc., are used merely to distinguish elements with similar properties, not to indicate or imply relative importance or a specific order.

[0041] The terms “include,” “comprising,” or any other variation thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0042] Please refer to Figures 1 to 4 As shown, the present invention provides a micro / nano functional device, including a substrate layer 1 and a structural layer 2 formed on the substrate layer 1. The structural layer 2 is provided with patterned grooves 21, and the grooves 21 have at least one dense layer 3, which is conformal to the grooves 21, and the porosity of the dense layer 3 is less than 10%.

[0043] In one specific embodiment, the orthographic projection of the grooves 21 distributed in the structural layer 2 onto the substrate layer 1 forms a pattern such as a square grid, hexagonal grid, regular polygonal grid, irregular grid, and parallel lines. The cross-sectional shape of the grooves 21 can be square, rectangular, arc-shaped, or irregular. The depth H of the grooves 21 is 2μm-100μm, and for example, the depth H is 2μm, 5μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, or 100μm; the width W of the grooves 21 is 50nm-50μm, and for example, the width W is 50nm, 300nm, 500nm, 800μm, 1μm, 5μm, 10μm, 15μm, 20μm, 30μm, 40μm, or 50μm.

[0044] In one specific embodiment, the dense layer 3 is a metal layer, and the material of the metal layer includes one or more combinations of aluminum, copper, nickel, chromium and silver. The thickness of the metal layer is 5nm-2μm. For example, the thickness of the metal layer is 5nm, 30nm, 70nm, 100nm, 200nm, 300nm, 400nm, 600nm, 800nm, 1μm, 1.5μm and 2μm.

[0045] In another embodiment, the dense layer 3 is a dielectric layer, which includes an inorganic dielectric material, such as metal oxide, silicon dioxide, zinc sulfide, and magnesium fluoride. The metal oxide includes one or more of titanium dioxide, iron tetroxide, copper oxide, aluminum oxide, zinc oxide, and indium tin oxide. The thickness of the dielectric layer is 50 nm to 1 μm; for example, the thickness of the dielectric layer is 50 nm, 70 nm, 100 nm, 150 nm, 200 nm, 300 nm, 500 nm, 700 nm, 800 nm, 900 nm, or 1 μm. Optionally, the dielectric layer can be an organic dielectric material, including PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid)), polyaniline, and polypyrrole. The thickness of the dielectric layer is 200nm-5μm. For example, the thickness of the dielectric layer is 200nm, 500nm, 800nm, 1μm, 2μm, 3μm, 4μm, or 5μm.

[0046] In some embodiments, multiple dense layers 3 can be provided in the groove 21 according to actual needs. By controlling the thickness of one of the dense layers 3, it can be made into a semi-transparent and semi-reflective layer with dual functions of optical adjustment and physical protection: on the one hand, it can adjust the light transmission and reflection characteristics and optimize the optical performance of the device; on the other hand, it can effectively protect the adjacent dense layers 3 in the groove 21 in subsequent processes, preventing them from being damaged by mechanical or chemical action during processing, thereby improving the overall reliability and long-term stability of the device.

[0047] Optionally, a light-absorbing layer 4 adjacent to the dense layer 3 can be formed on the structural layer 2 using methods such as capillary adsorption, atomic layer deposition (ALD), chemical vapor deposition, or coating. The light-absorbing layer 4 is conformal to the dense layer 3, and its thickness is 10nm-500nm. For example, the thickness of the light-absorbing layer 4 is 10nm, 50nm, 80nm, 100nm, 200nm, 300nm, 400nm, or 500nm. The light-absorbing layer 4 can provide physical protection for the dense layer 3, preventing it from being damaged in subsequent processes, and helping to improve the structural integrity, reliability, and product yield of the device. At the same time, this structure can be adapted to the functional requirements of different micro / nano functional devices.

[0048] The micro-nano functional device structure of the present invention is flexible in design. The dense layer 3 and the light-absorbing layer 4 can be selected and configured according to the actual application requirements. It also supports the arrangement of single-layer or multi-layer functional structures on one or both sides of the substrate, and has a wide range of applicable scenarios and strong adaptability.

[0049] Please refer to Figures 5 to 7 As shown, the present invention also provides a method for fabricating micro / nano functional devices, specifically including the following steps: S1: Provide a substrate layer 1, and apply an adhesive layer 20 onto the substrate layer 1.

[0050] In one specific embodiment, the substrate layer 1 is a polymer material with good light transmittance, flexibility and chemical stability, such as polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), and polyimide (PI).

[0051] S2: Using a pre-made patterned mold, an imprint is made on the adhesive layer 20. After the adhesive layer 20 is cured, a structural layer 2 with patterned grooves 21 and platforms 22 is formed.

[0052] In one specific embodiment, the adhesive layer 20 is made of materials such as UV adhesive or thermosetting adhesive.

[0053] S3: A barrier layer 5 is provided on the surface of platform 22, and a dense layer 3 is provided on structural layer 2.

[0054] Specifically, a water-based and / or oil-based material is applied to the surface of platform 22 by contact coating to form a barrier layer 5.

[0055] Please refer to Figure 8As shown, in one specific embodiment, in step S3, a barrier layer 5 is formed on the surface of platform 22 of structural layer 2 by contact coating with an aqueous material. The aqueous material can be aqueous polyurethane, aqueous acrylic, hydrophilic tributylphenol derivatives, etc. Exemplarily, firstly, the gravure plate 6 is directly contacted with the hydrophilic tributylphenol derivative solution placement tank, causing the hydrophilic tributylphenol derivative to adhere to the surface of the gravure plate 6; then, the hydrophilic tributylphenol derivative on the surface of the gravure plate 6 is transferred to the adjacent surface of the rubber roller 7. Next, the substrate film is placed on the guide roller 8, and the hydrophilic tributylphenol derivative is flexographically printed onto the surface of platform 22 of structural layer 2 through the rubber roller 7, thereby forming the barrier layer 5. Simultaneously, the surface of platform 22 is dried to ensure that it does not flow. This method enables the barrier layer 5 to adhere precisely to the surface of the platform 22 without flowing into the groove 21. Because the hydrophilic tributylphenol derivative barrier layer 5 has extremely low adhesion to the structural layer 2 and subsequent structural materials, it is easy to remove completely in subsequent processes.

[0056] Please refer to Figure 9 As shown, in another specific embodiment, a contact-coated oily material is used to form the barrier layer 5. The oily material includes fluorinated oil, etc. Exemplarily, firstly, a fluorinated oil tank is prepared and heated to evaporate the fluorinated oil. During the evaporation process, a relative distance is maintained between the fluorinated oil tank and the gravure plate 6, and the fluorinated oil vapor condenses on the surface of the gravure plate 6, and then transfers to the surface of the adjacent rubber roller 7. Next, the substrate film is placed on the cooling roller 9, and the fluorinated oil is flexographically printed onto the surface of the platform 22 of the structural layer 2 through the rubber roller 7 to form the barrier layer 5. This process ensures that the fluorinated oil forms a stable adhesion on the surface of the platform 22 and is non-flowing, thereby preventing it from flowing into the groove 21. Because the adhesion between the fluorinated oil and the structural layer 2 and subsequent structural materials is extremely low, it is easy to remove completely in subsequent processes.

[0057] The thickness of the barrier layer 5 ranges from 10nm to 500nm, and is less than the thickness of the structural layer 2. For example, the thickness of the barrier layer 5 is 10nm, 30nm, 50nm, 100nm, 120nm, 150nm, 170nm, 180nm, 190nm, 200nm, 300nm, 400nm, or 500nm. This barrier layer 5 is designed to fully meet the process requirements of high-precision device fabrication. It allows for easy removal of the layer and the material above it in subsequent processes, enabling targeted recycling and reuse of materials, significantly reducing raw material loss and improving process economy. Simultaneously, it ensures a highly planar interface morphology on the device surface, facilitating seamless integration with various subsequent planarization processes and providing a foundation for good compatibility in the fabrication of multilayer structures.

[0058] Furthermore, in one specific embodiment, a metal material is deposited on the structural layer 2 using processes such as vapor deposition, sputtering, and atomic layer deposition (ALD). The metal material includes one or more of aluminum, copper, nickel, chromium, and silver, which adhere to the barrier layer 5 and the groove 21 to form a uniform metal film, i.e., a dense layer 3, which is conformally fitted to the groove 21. Compared with the prior art, this embodiment uses nickel, chromium, copper, and aluminum as metal materials, which can significantly reduce raw material costs. Moreover, these metals are highly adaptable and can be used in various application environments. Even if silver is selected as the metal material, the amount of silver used can be effectively reduced in this technical solution. The silver does not need to fill the groove 21, and the silver adhering to the surface of the barrier layer 5 can be recycled and reused in subsequent processes, thereby reducing the overall manufacturing cost. The entire manufacturing process can be achieved using a roll-to-roll process without high-temperature sintering, which not only greatly improves production efficiency but also better meets the requirements of mass production. In other embodiments, this step can be repeated multiple times to form multiple layers of dense layer 3, or it can be combined with a water-plating metal process according to actual needs. The thickness of the metal layer ranges from 5nm to 2μm. For example, the thickness of the metal layer is 5nm, 10nm, 50nm, 100nm, 200nm, 300nm, 500nm, 800nm, 1μm, 1.5μm, or 2μm.

[0059] Furthermore, when the dense layer 3 is a conductive metal, it conformally covers the sidewalls and bottom of the groove 21, forming parallel conductive paths, which helps to reduce the overall resistance, improve the current carrying capacity and reduce heat generation, and can further improve the conductivity of the device.

[0060] Please refer to the three-dimensional morphology diagram of the dense layer 3 prepared in this embodiment within the groove 21. Figure 10 As shown, the metal layer is made of aluminum, which is attached to the bottom and inner wall of the patterned groove 21. The thickness of the aluminum is 529 nm. The surface of the platform 22 is covered with a barrier layer 5 and aluminum, and the thickness of the barrier layer 5 is 355 nm.

[0061] In another specific embodiment, inorganic dielectric materials are deposited using processes such as evaporation, sputtering, atomic layer deposition (ALD), or chemical vapor deposition. The inorganic dielectric materials include metal oxides, silicon dioxide, zinc sulfide, magnesium fluoride, etc. The metal oxides include one or more of titanium dioxide, iron tetroxide, copper oxide, aluminum oxide, zinc oxide, indium tin oxide, etc., which are deposited on the barrier layer 5 and in the groove 21 to form a dense layer 3. The dense layer 3 is conformal to the groove 21. The thickness of the dielectric layer ranges from 50nm to 1μm. For example, the thickness of the dielectric layer is 50nm, 70nm, 100nm, 150nm, 200nm, 300nm, 500nm, 700nm, 800nm, 900nm, or 1μm. In other embodiments, organic dielectric materials are applied using methods such as coating. These materials include PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic acid)), polyaniline, polypyrrole, etc. The thickness of the dielectric layer ranges from 200 nm to 5 μm; for example, the thicknesses are 200 nm, 500 nm, 800 nm, 1 μm, 2 μm, 3 μm, 4 μm, and 5 μm. The dielectric layer can be used to achieve functions such as optical modulation, dielectric isolation, or electrochemical activity.

[0062] Please refer to Figure 11 As shown, optionally, before or after the formation of the dense layer 3, a light-absorbing layer 4 adjacent to the dense layer 3 can be formed on the structural layer 2 by capillary adsorption, atomic layer deposition (ALD), chemical vapor deposition, coating, or other methods. The light-absorbing layer 4 is conformal to the dense layer 3, and its thickness is 10nm-500nm. For example, the thickness of the light-absorbing layer 4 is 10nm, 50nm, 80nm, 100nm, 200nm, 300nm, 400nm, or 500nm. For example, when the light-absorbing layer 4 uses nanoparticles, the nanoparticle mixture can be drawn into the groove 21 through capillary adsorption, followed by low-temperature baking. The moisture evaporates from the groove 21 to the outside, forming a continuous capillary flow from the inside to the outside, thereby continuously transporting the nanoparticles into the groove 21. Based on the van der Waals forces between the nanoparticles, the nanoparticles are uniformly deposited on the surface of the dense layer 3 in the groove 21 and dried to form the light-absorbing layer 4. Setting up the light-absorbing layer 4 can not only enable different functions of micro and nano functional devices, but also provide catalytic active sites to enhance electrochemical performance in some specific applications, and adjust the surface roughness to enhance light scattering or light capture effects; at the same time, it can also serve as a protective layer to prevent the dense layer 3 from being damaged in subsequent processes.

[0063] Please refer to Figure 12As shown, in some embodiments, multiple dense layers 3 can be set to form a composite configuration to meet the needs of actual devices. A semi-transparent and semi-reflective effect can also be achieved by controlling the thickness of one of the dense layers 3, thereby adjusting the light transmission and reflection characteristics to realize optical enhancement or wavelength selection functions. Simultaneously, it provides physical protection for adjacent dense layers 3 and supports the arrangement of single-layer or multi-layer functional structures on one or both sides of the substrate, exhibiting wide applicability and strong adaptability.

[0064] S4: Remove all material from platform 22 to form micro / nano functional devices.

[0065] In one specific embodiment, in step S4, since the bonding force between the barrier layer 5 composed of water-based or oil-based materials and the structural layer 2 and the materials of each layer is weak, all materials on the platform 22 can be removed in the following ways: (1) Physical mechanical polishing or chemical mechanical polishing (CMP) can be used to remove the barrier layer 5 and the materials on the barrier layer 5 from the surface of the platform 22. Since the bonding force between the layers on the platform 22 is weak, the mechanical friction can easily exceed the interfacial bonding strength, thereby achieving efficient material removal. When chemical mechanical polishing (CMP) is selected, the polishing liquid can be one or more of hydrogen peroxide, ammonia, colloidal silica, and isopropanol; (2) Adhesive materials are used for adhesion removal, and the weakly bonded barrier layer 5 and all materials on the barrier layer 5 are transferred and removed together; while the materials in the groove 21 are retained because they are firmly attached in the groove 21. In the above removal process, the barrier layer 5 and the materials on the barrier layer 5 recovered from the platform 22 can be recycled and reused, which is beneficial to resource conservation and environmental protection of the process.

[0066] The micro-nano functional devices obtained by the above preparation method have advantages such as complete structure, stable performance, high preparation efficiency, and low cost. They are suitable for applications such as privacy devices, transparent electrodes, structured color devices, magnetic induction absorbing devices, piezoelectric sensors, solar electrodes, electrochromic devices, wire-grid polarization devices, electroluminescent devices, and hidden optical devices. Details are as follows: Example 1 This embodiment provides a micro / nano functional device, specifically a privacy screen device, which includes a substrate layer 1 and a structural layer 2 disposed on the substrate layer 1. The structural layer 2 has patterned grooves 21. The structural layer 2 is made of ultraviolet-curable resin or thermosetting resin.

[0067] Please refer to Figure 1As shown, in one specific embodiment, the groove 21 includes a dense layer 3, which is a dielectric layer and conforms to the groove 21. First, an adhesive layer 20 is coated on the substrate layer 1, and a pre-made patterned mold is used to imprint one side of the adhesive layer 20. After the adhesive layer 20 cures, a structural layer 2 with patterned grooves 21 and platforms 22 is formed. A barrier layer 5 is coated on the surface of the platform 22 of the structural layer 2. The barrier layer 5 can be a water-based material or an oil-based material, etc., and the barrier layer 5 is only formed on the platform 22 of the structural layer 2. Subsequently, processes such as vapor deposition, sputtering, atomic layer deposition (ALD), and chemical vapor deposition can be used to deposit a black metal oxide on the surface of the structural layer 2. The black metal oxide can be materials such as iron oxide, black copper oxide, etc., so that it is uniformly attached along the inner wall and bottom of the groove 21 to form a continuous and dense dielectric layer. This dense structure effectively fills the interior of the groove 21, avoiding light scattering disorder caused by a loose structure. Simultaneously, its surface roughness can be controlled below 10 nm, contributing to the formation of a consistent optical interface. The dielectric layer thickness is 50 nm-1 μm, effectively absorbing large-angle incident light, thus achieving significant optical isolation within a specific viewing angle range. Subsequently, the barrier layer 5 and attached materials on the surface of the platform 22 are removed by physical or chemical methods. The recovered metal oxides, after processing, can be used in subsequent deposition processes, achieving material recycling.

[0068] Please refer to Figure 2 As shown, in another specific embodiment, the groove 21 includes a light-absorbing layer 4 and a dense layer 3 disposed on the light-absorbing layer 4. The dense layer 3 is a dielectric layer, and the light-absorbing layer 4, the dense layer 3, and the groove 21 are conformally oriented. Using capillary adsorption and directional assembly technology, black pigment nanoparticles, including aniline black, are dispersed in a low surface tension solvent. By controlling the solution concentration, wetting angle, and evaporation rate, the aniline black nanoparticles self-assemble into a tightly packed arrangement within the groove 21. After drying, the light-absorbing layer 4 is formed. The thickness of this light-absorbing layer is 200nm-500nm, and its high filling density forms a nearly continuous light-absorbing structure. Further, a dielectric layer can be formed on the surface of the light-absorbing layer 4 using a low-temperature atomic layer deposition (ALD) process. The dielectric layer material includes titanium dioxide, zinc oxide, or aluminum oxide, and its refractive index is adjustable in the range of 1.8-2.5. The thickness of the dielectric layer is 100nm-300nm. This dielectric layer can, on the one hand, produce orderly scattering of incident light, enhancing forward transmittance and lateral extinction effect; on the other hand, it can seal and stabilize the structure of the underlying light-absorbing layer 4, improving the overall environmental stability and mechanical durability of the device, thereby maintaining long-lasting and reliable privacy protection performance over a wide viewing angle range. Subsequently, the barrier layer 5 and all materials on it on the surface of platform 22 are removed by physical or chemical means. The recovered pigment nanoparticles can be reused in the process after redispersing treatment, achieving efficient reuse of materials.

[0069] The dense composite structure formed in the groove 21 by the above process not only achieves precise control of the optical path, but also enhances the optical consistency, structural stability and environmental adaptability of the device, making it a promising candidate for application in the field of privacy protection for displays.

[0070] Example 2 Please refer to Figure 1 As shown, the present invention provides a micro / nano functional device, specifically a transparent electrode, comprising a substrate layer 1 and a structural layer 2 disposed on the substrate layer 1. Patterned grooves 21 are formed on the structural layer 2, with a period P of 50 μm-500 μm for the grooves 21. A dense layer 3, which is a metal layer, is contained within each groove 21 and conforms to the grooves 21.

[0071] In one specific embodiment, an adhesive layer 20 is coated onto a substrate layer 1, and a pre-made patterned mold is used to imprint one side of the adhesive layer 20. After the adhesive layer 20 cures, a structural layer 2 with patterned grooves 21 and platforms 22 is formed. First, a water-based or oil-based material is coated onto the surface of the platform 22 to form a barrier layer 5. Subsequently, a metal material is deposited on the surface of the structural layer 2 using processes such as vapor deposition, sputtering, or atomic layer deposition (ALD). The metal material can be one or more of aluminum, copper, nickel, chromium, and silver, thereby forming a continuous and dense metal layer with a thickness of 200 nm to 2 μm on the bottom and inner wall of the grooves 21 and on the platform 22. Afterward, all materials on the surface of the platform 22 are removed by physical or chemical means. During this process, the metal material recovered from the platform 22 can be recycled, which helps to save resources and improve the environmental friendliness of the process.

[0072] Compared with existing technologies, this embodiment uses aluminum, copper, nickel, and chromium as conductive metals, which can significantly reduce raw material costs by hundreds of times and greatly improve preparation efficiency. Furthermore, these metals have good process adaptability and can be applied to various production conditions. Even when silver is used as the conductive material, the amount of silver used can be effectively reduced in this technical solution. The silver adhering to the surface of the barrier layer 5 can be recycled and reused in subsequent processes, thereby reducing the overall manufacturing cost. In other embodiments, the above steps can be repeated multiple times to form the metal layer, or a water-plating metal process can be further combined to enhance the conductivity of the electrode.

[0073] In this embodiment, the transmittance of the transparent electrode is greater than 85%. The transmittance is mainly calculated based on the mesh aperture ratio, that is, the proportion of the total area not covered by metal. Light primarily passes through these openings. For example, when the projection of the grooves 21 on the structural layer 2 onto the substrate layer 1 forms a square grid, the side length L of one square cell is the period P of the groove 21. Groove width 21 The total area of ​​a unit The area of ​​a blank square in a unit is the area of ​​the square minus the area covered by the internal metal. The side length of the blank square is l = Therefore, the opening ratio That is, the transmittance is 93.4%.

[0074] In this embodiment, the sheet resistance of the transparent electrode is less than 10. For a regular square grid, when the metal layer is uniformly deposited within the groove 21, its sheet resistance can be calculated by treating the grid cells as an equivalent resistor network, using the following formula:

[0075] in: : Fangzhu; Electrical conductivity of metals; : Thickness of the metal layer.

[0076] For example, using aluminum as the metal layer, the electrical conductivity of aluminum is approximately S / m. When the metal layer thickness is 500 nm, the side length L of a single square unit is... Groove width 21 calculate, = In this embodiment, the metal material conforms to the groove 21 and is deposited on the bottom and inner wall of the patterned groove 21, forming a U-shaped cross-section. Because the sidewalls contribute additional conductive area, the conductivity is greatly improved, and the sheet resistance is further reduced to less than R. s One-third.

[0077] Please refer to Figure 3 As shown, in another specific embodiment, carbon nanoparticles can be filled using capillary adsorption or other methods, allowing them to be continuously and directionally deposited on the inner surface of the groove 21. After drying, a light-absorbing layer 4 is formed on the surface of the metal layer. The light-absorbing layer 4 is conformal to the metal layer, and its thickness is 10 nm-500 nm. Since the size of the carbon nanoparticles is much smaller than the wavelength of visible light, incident light undergoes multiple scattering and reflections on its surface and between its pores. Each interaction with the carbon walls results in partial absorption, thus giving the light-absorbing layer 4 significant light absorption characteristics. On the one hand, this significantly reduces the reflectivity on the observation side, effectively suppressing glare and visual interference caused by ambient light reflected through the metal layer. On the other hand, it enhances the light absorption capacity of the electrodes for incident light, reduces optical losses, and thereby improves charge collection efficiency and the overall photoelectric conversion performance of the device. Similarly, all materials on the surface of the platform 22 can be removed by physical or chemical methods to achieve material recycling and reuse.

[0078] Example 3 Please refer to Figure 2As shown, this invention provides a micro / nano functional device, specifically a structural color device, including a substrate layer 1 and a structural layer 2 disposed on the substrate layer 1. The structural layer 2 has patterned grooves 21, and a light-absorbing layer 4 is disposed within each groove 21. The light-absorbing layer 4 is conformally oriented to the grooves 21, and its thickness ranges from 10 nm to 500 nm. The light-absorbing layer 4 can be carbon nanoparticles or other pigment particles. A dense layer 3 is disposed on the light-absorbing layer 4. In this embodiment, the dense layer 3 is a metal layer, preferably made of aluminum, used for light reflection to increase the saturation of the presented color. The metal layer is conformally oriented to the light-absorbing layer 4, and its thickness ranges from 20 nm to 50 nm. In some embodiments, the dense layer 3, i.e., the metal layer, can be disposed within the grooves 21 first, followed by the light-absorbing layer 4. This structural color device can be used in the field of decorative printing, for example, in a decorative film. The decorative film consists of a microlens array layer formed on the other side of the substrate of the structural color device. The microlens array layer includes a plurality of microlenses, each corresponding to a groove 21. A moiré magnified image is obtained through the double-layer superposition of the periodic grooves 21 and the microlens array. The grooves 21 are located on the focal plane of the microlenses. In another specific embodiment, the phase of light field propagation is multidimensionally controlled by the "micro-nano structural morphology" on the grooves 21, reconstructing the light field distribution in space to form a three-dimensional (light field) image. The grooves 21 are located outside the focal plane of the microlenses.

[0079] An adhesive layer 20 is coated onto a substrate layer 1, and a pre-made patterned mold is used to imprint one side of the adhesive layer 20. After the adhesive layer 20 cures, a structural layer 2 with patterned grooves 21 and platforms 22 is formed. A barrier layer 5 is coated on the surface of the platform 22 of the structural layer 2. The barrier layer 5 can be a water-based or oil-based material, etc., and the barrier layer 5 is only formed on the platform 22 of the structural layer. Water-based nano-pigment particles are coated onto the structural layer 2 and dried to form a light-absorbing layer 4. A dense layer 3 is formed on the light-absorbing layer 4. In this embodiment, the dense layer 3 is a metal layer. The formation method is not particularly limited and can be vapor deposition, sputtering, atomic layer deposition (ALD), etc. Due to the presence of the barrier layer 5 and the low adhesion of metal and particulate materials to the barrier layer 5, they can be easily removed by physical or chemical means, ultimately forming a structural color device.

[0080] Example 4 Please refer to Figure 3 As shown, this embodiment provides a micro-nano functional device, specifically a magnetic induction absorbing device, which includes a substrate layer 1 and a structural layer 2 disposed on the substrate layer 1. The structural layer 2 is provided with patterned grooves 21. The grooves 21 sequentially include a dense layer 3 and a light-absorbing layer 4 disposed on the dense layer. The dense layer 3, the light-absorbing layer 4 and the grooves 21 are conformal.

[0081] In this design, the dense layer 3 is a metal layer made of chromium, with a thickness of 15nm-25nm. The light-absorbing layer 4 uses magnetic nanoparticles, including one or more of the following: iron(II,III) oxide nanoparticles, γ-iron oxide nanoparticles, nickel oxide nanoparticles, manganese oxide nanoparticles, and cobalt nanoparticles. The thickness of the light-absorbing layer 4 is 300nm-500nm. In other embodiments, the thickness of the light-absorbing layer 4 can be increased according to actual needs.

[0082] In the preparation process, an adhesive layer 20 is coated on the substrate layer 1, and a pre-made patterned mold is used to imprint one side of the adhesive layer 20. After the adhesive layer 20 cures, a structural layer 2 with patterned grooves 21 and platforms 22 is formed. Subsequently, a barrier layer 5 is coated on the platform 22 of the structural layer 2, so that the barrier layer 5 only covers the platform 22. The barrier layer 5 is made of water-based or oil-based materials. Then, chromium is deposited on the surface of the structural layer 2 using processes such as evaporation, sputtering, and atomic layer deposition (ALD) to form a metal layer covering the barrier layer 5 and the inner surface of the grooves 21. To further improve the surface chemical activity of this metal layer, it can be treated with oxygen plasma or ultraviolet-ozone to generate a chromium oxide passivation layer rich in hydroxyl groups on its surface, thereby significantly increasing the active sites that can be used for chemical bonding. Next, magnetic nanoparticles are dispersed in a suitable solvent to form a stable suspension, and the surface of the nanoparticles is modified with a silane coupling agent with terminal functional groups such as carboxyl or amino groups. These ligands can not only prevent particle aggregation through steric hindrance, but their terminal functional groups can also interact specifically with the aforementioned activated chromium layer surface.

[0083] Utilizing capillary adsorption, a suspension of surface-modified magnetic nanoparticles is driven into groove 21, where it is dried to form light-absorbing layer 4. After filling, a low-temperature heat treatment is performed. This process effectively promotes the dehydration condensation reaction between carboxyl groups and hydroxyl groups on the chromium oxide surface, forming strong ester or coordination bonds, while simultaneously enhancing the cohesive strength of light-absorbing layer 4. This results in the construction of a stable and dense composite functional layer within groove 21. Finally, all materials on platform 22 are removed using physical or chemical methods to complete the device fabrication. This structure ensures the device's absorption performance and reliability.

[0084] Example 5 Please refer to Figure 4 As shown, this embodiment provides a micro / nano functional device, specifically a piezoelectric functional device, which includes a substrate layer 1 and a structural layer 2 disposed on the substrate layer. The structural layer 2 is provided with patterned grooves 21, and the grooves 21 contain two dense layers 3 in sequence, the dense layers 3 being conformal to the grooves 21.

[0085] The first dense layer 31 is a metal layer made of aluminum or chromium, with a thickness of 100nm-150nm. It serves as the lower electrode of the device, providing stable electrical contact and charge collection pathway. The second dense layer 32 is a dielectric layer with a thickness of 800nm-1μm. The dielectric layer effectively enhances the piezoelectric response performance of the device.

[0086] An adhesive layer 20 is coated onto the substrate layer 1, and a pre-made patterned mold is used to imprint one side of the adhesive layer 20. After the adhesive layer 20 cures, a structural layer 2 with patterned grooves 21 and platforms 22 is formed. Subsequently, a barrier layer 5 is coated on the surface of the platform 22 of the structural layer 2, so that the barrier layer 5 only covers the platform 22. The barrier layer 5 is made of water-based or oil-based materials, etc. Then, aluminum or chromium is deposited on the surface of the structural layer 2 using processes such as evaporation, sputtering, and atomic layer deposition (ALD) to form a metal layer covering the barrier layer 5 and the inner surface of the grooves 21. The barium titanate nanoceramic particles are surface-modified with a silane coupling agent to improve their interfacial compatibility with the polymer. Modified nano-ceramic particles were mixed with a poly(vinylidene fluoride-trifluoroethylene) copolymer solution at a certain volume ratio. The mixture was then subjected to high-speed shearing and ultrasonic treatment to obtain a high-solids-content composite slurry with shear-thinning properties and uniform stability. This composite slurry was then coated into grooves 21 and subjected to thermal annealing to crystallize the polymer matrix, forming a dielectric layer. Finally, all material located on platform 22 was removed by physical or chemical means. An electrode layer was further fabricated on structural layer 2, and a DC high-voltage electric field was applied above and below it to orient the domains of the nano-ceramic particles and the polymer dipoles, thereby activating their piezoelectric properties.

[0087] Example 6 Please refer to Figure 4 As shown, this invention provides a micro / nano functional device, specifically a perovskite solar cell, comprising a substrate layer 1 and a structural layer 2 disposed on the substrate layer 1. Patterned grooves 21 are formed on the structural layer 2. Each groove 21 contains two dense layers 3, both of which are metal layers conformally to the grooves 21. For ease of understanding, the materials of the dense layers 3 are distinguished by different colors in the accompanying drawings.

[0088] In one specific embodiment, the substrate layer 1 is a flexible polyimide (PI) film with good temperature resistance. A UV-curable or heat-curable adhesive layer 20 is coated on the substrate layer 1, and a pre-patterned mold is used to imprint one side of the adhesive layer 20. After the adhesive layer 20 cures, a structural layer 2 with patterned grooves 21 and platforms 22 is formed. First, a water-based or oil-based material is coated on the surface of the platform 22 to form a barrier layer 5. Subsequently, aluminum is deposited on the surface of the structural layer 2 using processes such as evaporation, sputtering, or atomic layer deposition (ALD) to form a first dense layer 31 with a thickness of 20 nm-50 nm. Then, copper is deposited using the same or similar deposition process to form a second dense layer 32 with a thickness of 200 nm-500 nm. The first dense layer 31 mainly serves as an adhesion layer and a diffusion barrier layer, enhancing the adhesion of subsequent copper and preventing copper atoms from diffusing into the perovskite active layer. The second dense layer 32 serves as the main conductive layer of the electrode, providing a low-resistance current collection and transmission channel. The barrier layer 5 and its covering metal material are removed by physical or chemical means, thereby forming a metal electrode structure within the groove 21 and obtaining a structural layer surface with a smooth interface. Further, a layer of highly transparent and highly conductive indium tin oxide (ITO) with a thickness of 80nm-150nm is deposited on the structural layer 2 using processes such as reactive evaporation, sputtering, atomic layer deposition (ALD), or chemical vapor deposition, resulting in a smooth composite bottom electrode with controllable sheet resistance.

[0089] Optionally, a hole transport layer, a perovskite absorber layer, an electron transport layer, and a metal back electrode are sequentially fabricated on the composite bottom electrode to ultimately form a high-efficiency, flexible perovskite solar cell device. This process combines patterned substrates with selective deposition techniques, which facilitates fine patterning of the electrodes, low-defect interfaces, and good light management, thereby improving the photoelectric conversion efficiency and mechanical stability of the cell.

[0090] Example 7 Please refer to Figure 4 As shown, this invention provides a micro / nano functional device, specifically an electrochromic device, comprising a substrate layer 1 and a structural layer 2 disposed thereon. The structural layer 2 has periodically patterned grooves 21. Two conformally covered dense layers 3 are disposed within the grooves 21, including a first dense layer 31 serving as an adhesion and barrier layer, and a second dense layer 32 serving as the main conductive layer. Both the first dense layer 31 and the second dense layer 32 are metal layers. For ease of understanding, the materials of the dense layers 3 are distinguished by different colors in the accompanying drawings.

[0091] In one specific embodiment, the substrate layer 1 is a polyimide (PI) film with excellent temperature resistance and bending tolerance. An adhesive layer 20 is coated onto the substrate layer 1, and a pre-patterned mold is used to imprint one side of the adhesive layer 20. After the adhesive layer 20 cures, a structural layer 2 with patterned grooves 21 and platforms 22 is formed. First, a barrier layer 5 is formed by coating the surface of the platform 22 with an aqueous or oil-based material. Subsequently, metallic aluminum is deposited on the surface of the structural layer 2 using processes such as evaporation, sputtering, and atomic layer deposition (ALD) to form a first dense layer 31 with a thickness of 5 nm-20 nm. This layer primarily enhances interfacial adhesion, prevents copper ion diffusion, and improves the conformality of subsequent layers. Next, metallic copper is deposited using the same or similar deposition process to form a second dense layer 32 with a thickness of 80 nm-200 nm. This layer provides a low-resistance current path, supporting rapid charge injection and extraction of the device during electrochromic cycling. Subsequently, the barrier layer 5 and the metal material covering it are removed by physical or chemical means, thereby retaining only the conformal metal electrode structure within the groove 21 and obtaining a smooth surface morphology. Further, an electrochromic active material PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid)) with a thickness of 100nm-300nm is deposited on the structural layer 2 using a coating process. This layer serves as both an ion storage layer and a conductive layer, forming a composite bottom electrode with low sheet resistance and high transmittance modulation capability.

[0092] This composite electrode structure utilizes the low resistance of the metal layer to achieve a large-area uniform electric field distribution, and achieves transmittance modulation in the visible and near-infrared bands through the reversible redox reaction of PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid)). An ion-conducting layer, a counter electrode, and an encapsulation layer can be sequentially assembled on this electrode to form a complete flexible electrochromic device, suitable for applications such as smart car windows, building dimming curtain walls, and flexible displays. It possesses advantages such as fast response speed, good cycle stability, and the ability to be patterned and integrated onto curved surfaces.

[0093] Example 8 Please refer to Figure 4As shown, this invention provides a micro / nano functional device, specifically a wire-grid polarization device, comprising a substrate layer 1 and a structural layer 2 disposed on the substrate layer 1. The structural layer 2 has patterned grooves 21. In this embodiment, the structural layer 2 is a wire-grid structure. Multiple dense layers 3 are disposed within the grooves 21 of the wire-grid structure. To facilitate understanding, the materials of the dense layers 3 are distinguished by different colors in the accompanying drawings. The dense layers 3 are conformal to the grooves 21. The first dense layer 31 is a metal layer, including aluminum or a composite of aluminum and other metals, formed by vapor deposition or magnetron sputtering processes, and serves a reflective function to reflect s-polarized light (TE wave (s-wave)) parallel to the extension direction of the grooves 21. A second dense layer 32 is also disposed on the first dense layer 21. The second dense layer 32 is a dielectric layer, including magnesium fluoride, which serves to protect the metal layer. The thickness of the first dense layer 31 is 100nm-300nm, the thickness of the second dense layer 32 is 50nm-100nm, and the period P of the groove 21 is 100nm-400nm.

[0094] An adhesive layer 20 is coated onto a substrate layer 1, and a pre-made patterned mold is used to imprint one side of the adhesive layer 20. After the adhesive layer 20 cures, a structural layer 2 with patterned grooves 21 and platforms 22 is formed. A barrier layer 5 is coated onto the structural layer 2. The barrier layer 5 can be a water-based or oil-based material, and it is only formed on the surface of the platform 22 of the structural layer 2. A metal layer and a dielectric layer are formed sequentially on the structural layer 2. The formation method is not particularly limited, and can include methods such as vapor deposition, sputtering, atomic layer deposition (ALD), and chemical vapor deposition. Due to the presence of the barrier layer 5, the barrier layer 5 and the material covering it can be easily removed by physical or chemical means. The final wire-grid polarization device only has a metal layer and a dielectric layer within the grooves 21.

[0095] Example 9 Please refer to Figure 4 As shown, this invention provides a micro / nano functional device, specifically an electroluminescent device, comprising a substrate layer 1 and a structural layer 2 disposed on the substrate layer 1. Patterned grooves 21 are formed on the structural layer 2, and each groove 21 contains two dense layers 3. Both the first dense layer 31 and the second dense layer 32 are dielectric layers. For ease of understanding, the materials of the dense layers 3 are distinguished by different colors in the accompanying drawings. The dense layers 3 are conformally oriented to the grooves 21. The thickness of the first dense layer 31 is 80nm-100nm, and the thickness of the second dense layer 32 is 200nm-300nm.

[0096] In one specific embodiment, the substrate layer 1 is selected from soda-lime glass or flexible PET film. First, an adhesive layer 20 is coated onto the substrate layer 1, and a pre-made patterned mold is used to imprint one side of the adhesive layer 20. After the adhesive layer 20 cures, a structural layer 2 with patterned grooves 21 and platforms 22 is formed. A water-based or oil-based material is coated onto the surface of the platform 22 of the structural layer 2 to form a barrier layer 5. Subsequently, zinc oxide material is deposited on the structural layer 2 using a magnetron sputtering process, uniformly covering the surface of the barrier layer 5 and the bottom and sidewalls of the grooves 21, forming a first dense layer 31. Then, the substrate with this dielectric layer is placed in a hydrothermal reaction system containing zinc nitrate and hexamethylenetetramine, and the reaction is carried out at 90°C. During this process, zinc oxide nanowires grow epitaxially along the sidewalls perpendicular to the grooves 21, eventually filling the grooves and forming a highly ordered nanowire array structure.

[0097] Furthermore, a second dense layer 32 is formed by depositing a P-type semiconductor material on the surface of the zinc oxide nanowire array using atomic layer deposition (ALD), magnetron sputtering, or spin coating. Suitable P-type materials include, but are not limited to, nickel oxide, PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid)), or p-type gallium nitride. Since zinc oxide itself possesses N-type semiconductor properties, it forms a PN heterojunction structure upon contact with the P-type material. After completing the above layer structure, all material on the surface of platform 22 is removed by physical or chemical means to achieve material recycling. In addition, to enhance the electrical contact and light extraction efficiency of the device, a bottom electrode layer can be fabricated between the substrate layer 1 and the structural layer 2, and a top electrode layer can be fabricated on the structural layer 2, enabling the device to emit visible light.

[0098] In another specific embodiment, the groove 21 contains two dense layers 3, wherein the first dense layer 31 is a metal layer with a thickness of 200nm-500nm, and the second dense layer 32 is a dielectric layer with a thickness of 800nm-1μm.

[0099] To facilitate understanding of the materials of the dense layer 3, which are distinguished by different colors in the attached figures, the dense layer 3 is conformal to the groove 21.

[0100] First, a barrier layer 5 is coated onto structural layer 2, using the same material as in the previous embodiment. Then, metallic aluminum is deposited on structural layer 2 using metal deposition processes such as evaporation, sputtering, and atomic layer deposition (ALD), ensuring uniform adhesion of aluminum to the surface of barrier layer 5 and the inner wall of groove 21, forming a continuous and dense metal film. Next, zinc sulfide phosphor particles, high dielectric constant nanoparticles (such as barium titanate), and an organic binder (such as cyanoethyl cellulose solution) are uniformly mixed and ground into a slurry. This slurry is then spin-coated into groove 21, ensuring complete filling without voids. Subsequently, it is baked at an appropriate temperature to evaporate the solvent, forming a dielectric layer. Furthermore, a transparent conductive material such as indium tin oxide (ITO) can be deposited across the entire structural surface as a front electrode. By applying a voltage between the aluminum layer and the transparent conductive layer, visible light excitation and emission can be achieved.

[0101] In this embodiment, the aluminum metal is directly and firmly attached within the groove 21, forming a stable conductive path. The material on the platform 22 can be easily removed through physical or chemical processes, thereby ensuring effective electrical isolation between the functional and non-functional areas. During the removal of material from the platform 22, this material can be recycled and reused, which not only has environmental benefits but also improves material utilization and further enhances the economic efficiency of the process.

[0102] Example 10 Please refer to Figure 4 As shown, this embodiment provides a micro / nano functional device, specifically a hidden optical device, including a substrate layer 1 and a structural layer 2 disposed thereon. The groove 21 contains two dense layers 3: a first dense layer 31 is a metal layer, and a second dense layer 32 is a dielectric layer. The dense layers 3 are conformally fitted to the groove 21. The thickness of the metal layer is 100nm-200nm, and the thickness of the dielectric layer is 50nm-100nm. For ease of understanding, different colors are used to distinguish the materials of the dense layers 3 in the accompanying drawings.

[0103] In one specific embodiment, a PET film is used as the substrate layer 1. An adhesive layer 20 is coated on the substrate layer 1, and a pre-made patterned mold is used to imprint one side of the adhesive layer 20. After the adhesive layer 20 cures, a structural layer 2 with patterned grooves 21 and platforms 22 is formed. First, a barrier layer 5 is coated on the surface of the platform 22 of the structural layer 2. The barrier layer 5 can be made of water-based or oil-based materials. Subsequently, nickel or chromium is deposited on the structural layer 2 using processes such as vapor deposition, sputtering, or atomic layer deposition (ALD), so that the metal material covers the surface of the barrier layer 5 and the interior of the grooves 21, forming a metal layer. Then, tungsten oxide (WO3) is deposited on the metal layer using processes such as magnetron sputtering, vapor deposition, or atomic layer deposition (ALD), forming a dielectric layer. All materials on the platform 22 are removed by physical or chemical means.

[0104] Furthermore, an indium tin oxide (ITO) transparent electrode layer can be disposed on structural layer 2. When no voltage is applied, the dense layer material is in state A (transparent state), its effective refractive index matches the surrounding medium, and the device structure exhibits almost no scattering or diffraction of visible light, presenting a uniform transparent or matte appearance, with the preset information hidden. When a voltage is applied, the dense layer material switches to state B (tungsten oxide transforms into a blue absorption state), and its optical constants (including refractive index and extinction coefficient) change significantly, resulting in a strong refractive index contrast with the surrounding medium. In this state, the periodic groove array 21 behaves as an active photonic crystal or diffraction grating structure, capable of producing strong scattering, diffraction, or absorption of light of specific wavelengths, thereby revealing preset patterns, text, or structural colors at specific angles or under specific lighting conditions.

[0105] In summary, the micro / nano functional device fabrication method provided by this invention innovatively achieves in-situ densification and functional enhancement of the filling material within the groove under mild conditions. This method significantly improves the filling efficiency and utilization rate of the functional material while maintaining high pattern accuracy and interface integrity, simplifies the fabrication process, and expands the compatibility range between substrates and functional materials. Based on this, this method provides a versatile and industrially feasible technical route for manufacturing functional surfaces and devices that possess excellent optical performance, superior electrical properties, high reliability, and good economic efficiency, and can be widely applied in multiple cutting-edge fields.

[0106] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A structural color device, characterized in that, include: A substrate layer and a structural layer disposed on the substrate layer, wherein the structural layer has patterned grooves, and the grooves include at least one dense layer, wherein the dense layer is a metal layer and / or a dielectric layer.

2. The structural color device as described in claim 1, characterized in that, The material of the metal layer includes one or more of aluminum, copper, nickel, chromium, and silver, and the thickness of the metal layer ranges from 5 nm to 2 μm.

3. The structural color device as described in claim 1, characterized in that, The dielectric layer is made of metal oxide, and the thickness of the dielectric layer ranges from 50 nm to 1 μm.

4. The structural color device as described in claim 1, characterized in that, A light-absorbing layer is formed on the structural layer adjacent to the dense layer. The light-absorbing layer is conformal to the dense layer. The light-absorbing layer is made of carbon nanoparticles or pigment particles, and the thickness of the light-absorbing layer ranges from 10 nm to 500 nm.

5. The structural color device as described in claim 1, characterized in that, A microlens array layer is provided on the substrate and on the opposite side of the structural layer. The microlens array layer includes a plurality of microlenses, each corresponding to a groove. When the groove is on the focal plane of the microlens, a moiré magnified image is formed; when the groove is outside the focal plane of the microlens, a stereoscopic light field image is formed.

6. The structural color device as described in claim 1, characterized in that, The depth of the groove ranges from 2μm to 10μm, and the width of the groove ranges from 200nm to 10μm.

7. A method for preparing the structural color device according to any one of claims 1-6, characterized in that, Includes the following steps: S1: Provide a substrate layer, and apply an adhesive layer onto the substrate layer; S2: Using a pre-made patterned mold, an imprint is made on the adhesive layer, and after the adhesive layer is cured, a structural layer with patterned grooves and platforms is formed; S3: A barrier layer is provided on the surface of the platform, and a dense layer is provided on the structural layer; S4: Remove all material from the platform to form a structural color device.

8. The method for preparing a structural color device as described in claim 7, characterized in that, In step S3, a water-based material and / or an oil-based material is applied to the surface of the platform to form the barrier layer. The thickness of the barrier layer ranges from 10 nm to 500 nm, and the thickness of the barrier layer is less than the thickness of the structural layer.

9. The method for preparing a structural color device as described in claim 7, wherein in step S3, a metal material is deposited using a vapor deposition or sputtering process, the metal material comprising one or more of aluminum, copper, nickel, chromium, and silver, so that it adheres to the barrier layer and the groove to form the dense layer.

10. The method for preparing a structural color device as described in claim 7, characterized in that, In step S3, metal oxides are deposited by vapor deposition or sputtering to adhere to the barrier layer and the groove to form the dense layer.

11. The method for fabricating a structural color device as described in claim 7, wherein in step S3, before or after the formation of the dense layer, a light-absorbing layer adjacent to the dense layer is disposed in the groove.

12. The method for preparing a structural color device as described in claim 7, characterized in that, In step S4, one or more of the following processes are used to remove all materials from the platform: physical mechanical polishing, chemical mechanical polishing, and adhesive transfer.

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