Laser colored drawing and anti-counterfeiting method and system based on aluminum-based material

Abstract

The invention discloses a laser colored drawing and anti-counterfeiting method and system based on an aluminum-based material. The method comprises the following steps: transferring prepared ink to a glass substrate through a pipette, and fixing the glass substrate to a laser processing system; a laser beam is focused on the interface of the ink and the glass substrate, and the aluminum hydroxide micro-nano structure is induced to grow and form on the surface of the substrate through a laser local photothermal effect; segmenting and slicing the to-be-processed image to generate point cloud data; controlling a focused laser beam to perform two-dimensional patterning scanning according to the point cloud data, and regulating and controlling the structural color presented by the aluminum hydroxide microstructure in the scanning process; taking down the glass substrate from the laser processing system, and carrying out subsequent washing and nitrogen blow-drying treatment by using deionized water to realize the colored drawing of the aluminum-based structural color; colored drawing information encryption and label anti-counterfeiting are realized by using a solution corrosion method. According to the invention, laser colored drawing, information encryption and anti-counterfeiting of single-color and multi-color aluminum-based structural color devices are realized.

Description

Technical Field

[0001] The present invention relates to the fields of laser processing and label anti-counterfeiting, and in particular to a laser painting based on aluminum-based materials and an anti-counterfeiting method and system thereof. Background Art

[0002] Structural color is produced by the reflection, refraction, scattering, or interference of light by the microscopic structures on or within an object. Its color development relies on the subtle structure of biological surfaces, and can be altered by changing the observer's angle or the periodic structure of the surface. Currently, the main methods for producing structural color include inkjet printing, which creates microscopic periodic structures by controlling the distribution, thickness, and arrangement of ink droplets; electron beam lithography, which etches microstructures of varying sizes, shapes, and arrangements by precisely controlling the electron beam's scanning path and energy; and nanoimprinting, which physically transfers nanoscale structures to a substrate surface to create periodic or regular nanostructures. These methods suffer from disadvantages such as low resolution, poor ink stability, complex processing, slow processing, high costs, and high substrate requirements.

[0003] As an advanced micro-nano processing method, laser direct writing technology has the advantages of high energy density, extremely small heat-affected zone and excellent processing resolution, and has attracted widespread attention from researchers at home and abroad. The focal point of the laser beam can be regarded as a flexible and controllable micro-reactor, which can be used to achieve high-precision fixed-point preparation of materials. For this reason, people have tried to use laser as a heat source to process thin films of different thicknesses and periods on different heat-absorbing substrates in one step, and control the color by changing the thickness of the film. However, this method has problems such as the need for a high-cost clean room environment, complex and high-cost coating process, and waste of materials in subtractive manufacturing. At the same time, there are certain limitations in the anti-counterfeiting encryption effect of structural color. Summary of the Invention

[0004] The main purpose of the present invention is to provide a laser painting based on aluminum-based materials and its anti-counterfeiting method and system, establish the optimization process parameter range of aluminum hydroxide microstructure and the dynamic control range of structural color, and at the same time, the present invention also realizes the reversible change of the color of the laser painting pattern through solution corrosion, realizing information encryption and anti-counterfeiting.

[0005] In order to achieve the aforementioned object of the invention, the present invention adopts the following scheme: One aspect of the present invention provides a laser painting method based on aluminum-based materials and an anti-counterfeiting method thereof, comprising: Step 1: Transfer the prepared ink to the glass substrate using a pipette gun, and fix the glass substrate to the laser processing system; Step 2: Focusing the laser beam on the interface between the ink and the glass substrate, the local photothermal effect of the laser can induce the growth of aluminum hydroxide micro-nanostructures on the substrate surface; Step 3: Segment and slice the image to be processed, and finally generate point cloud data; Step 4: Control the focused laser beam to perform two-dimensional patterned scanning based on the point cloud data. During the scanning process, control the laser exposure time and laser power to quantitatively control the geometric parameters of the aluminum hydroxide microstructure, and ultimately quantitatively control the structural color presented by the aluminum hydroxide microstructure; Step 5: Remove the glass substrate from the laser processing system, rinse it with deionized water, and blow dry it with nitrogen to achieve the final aluminum-based structural color painting. Step 6: Use solution corrosion method to realize encryption of painted information and anti-counterfeiting of labels.

[0006] In one embodiment, the ink is composed of aluminum nitrate and sodium hydroxide; the specific preparation method of the ink is: Aluminum nitrate nonahydrate and sodium hydroxide solid reagents were accurately weighed according to a molar concentration of 500 mM; The mixed solution is prepared by a graded dissolution method; A stirring bar was added and stirred under constant stirring conditions of a magnetic stirrer for half an hour. After the reaction was complete, the mixture was allowed to stand for one hour. The supernatant was filtered to prepare an aluminum nitrate solution containing sodium ions.

[0007] In one embodiment, the laser processing system includes a half-wave plate, a Glan-Taylor prism, an acousto-optic modulator, a pinhole, a galvanometer, a first lens, a second lens, and a light-emitting diode; wherein the laser passes through the half-wave plate and the Glan-Taylor prism combination to preliminarily control the laser power; the acousto-optic modulator is used to further fine-tune the laser power; the pinhole is used for spatial filtering of the laser; the galvanometer is used for deflecting the light beam; the first lens and the second lens deflect the light beam to the entrance pupil of the objective lens; and the light-emitting diode is used for illumination when the camera observes during the processing process.

[0008] In one embodiment, the segmentation process includes: first performing grayscale processing on the image to be processed to obtain a grayscale histogram of the entire image, and then dividing the entire image into two areas, namely a black area and a white area, through global threshold segmentation; wherein the black area is the target object area, and the white area is the background area.

[0009] In one embodiment, the slicing process includes: optimizing the slice file by adjusting the image scaling and single-point exposure spacing; wherein the single-point spacing of the slice is set to 500 nm.

[0010] In one embodiment, the solution corrosion method is used to achieve encryption of painted information and anti-counterfeiting of labels, specifically including: adding zirconium oxynitrate solution to the surface of a glass substrate, focusing the laser on the surface of the glass substrate, generating a local high temperature field to induce the zirconium oxynitrate solution to form a layer of zirconium oxide two-dimensional code pattern, and then adding the ink to the surface of the zirconium oxide two-dimensional code pattern to process a layer of aluminum hydroxide pattern on the surface of the zirconium oxide two-dimensional code pattern to hide the zirconium oxide two-dimensional code pattern inside, thereby achieving information encryption.

[0011] Another aspect of the present invention provides a laser painting system based on aluminum-based materials and an anti-counterfeiting system thereof, comprising: Glass substrate fixing module: used to transfer the configured ink to the glass substrate through the pipette gun and fix the glass substrate to the laser processing system; Structural forming module: used to focus the laser beam on the interface between the ink and the glass substrate, and through the local photothermal effect of the laser, it can induce the growth and formation of aluminum hydroxide micro-nanostructures on the substrate surface; The image processing module is used to segment and slice the image to be processed and finally generate point cloud data; The color painting quantitative control module is used to control the focused laser beam to perform two-dimensional pattern scanning based on the point cloud data. During the scanning process, the laser exposure time and laser power are controlled to quantitatively control the geometric parameters of the aluminum hydroxide microstructure, and ultimately quantitatively control the structural color presented by the aluminum hydroxide microstructure; The painting processing module is used to remove the glass substrate from the laser processing system, rinse it with deionized water and blow it dry with nitrogen, and finally achieve aluminum-based structural color painting; The anti-counterfeiting module is used to realize encryption of painted information and anti-counterfeiting of labels by using a solution corrosion method.

[0012] In one embodiment, the ink is composed of aluminum nitrate and sodium hydroxide; the specific preparation method of the ink is: Aluminum nitrate nonahydrate and sodium hydroxide solid reagents were accurately weighed according to a molar concentration of 500 mM; The mixed solution is prepared by a graded dissolution method; A stirring bar was added and stirred under constant stirring conditions of a magnetic stirrer for half an hour. After the reaction was complete, the mixture was allowed to stand for one hour. The supernatant was filtered to prepare an aluminum nitrate solution containing sodium ions.

[0013] In one embodiment, the laser processing system includes a half-wave plate, a Glan-Taylor prism, an acousto-optic modulator, a pinhole, a galvanometer, a first lens, a second lens, and a light-emitting diode; wherein the laser passes through the half-wave plate and the Glan-Taylor prism combination to preliminarily control the laser power; the acousto-optic modulator is used to further fine-tune the laser power; the pinhole is used for spatial filtering of the laser; the galvanometer is used for deflecting the light beam; the first lens and the second lens deflect the light beam to the entrance pupil of the objective lens; and the light-emitting diode is used for illumination when the camera observes during the processing process.

[0014] In one embodiment, the image processing module further includes a segmentation module, which is used to first perform grayscale processing on the image to be processed to obtain a grayscale histogram of the entire image, and then divide the entire image into two areas, namely a black area and a white area through global threshold segmentation; the black area is the target object area, and the white area is the background area.

[0015] In one embodiment, the image processing module further includes a slicing module for optimizing the slice file by adjusting the image zoom size and the single-point exposure spacing; wherein the single-point spacing of the slice is set to 500 nm.

[0016] In one embodiment, the anti-counterfeiting module further comprises: A QR code preparation module is used to form a layer of zirconium oxide QR code pattern on the surface of a glass substrate by laser; The QR code hiding module is used to process a layer of aluminum hydroxide pattern on the surface of the zirconia QR code pattern to hide the QR code pattern inside and realize information encryption.

[0017] Compared with the prior art, the present invention has at least the following advantages: (1) The embodiments of the present invention provide a laser painting method and anti-counterfeiting system based on aluminum-based materials. The aluminum-based structural color laser painting technology used therein has high precision and can realize sub-micron scale structure design and processing.

[0018] (2) The embodiments of the present invention provide a laser painting method and anti-counterfeiting system based on aluminum-based materials. The aluminum-based structural color laser painting technology used in the laser painting method consumes less materials, and the painted patterns are recyclable and low in cost.

[0019] (3) The embodiments of the present invention provide a laser painting method and anti-counterfeiting system based on aluminum-based materials. The laser painting pattern has a simple operation process and does not require a complicated process flow and a strict clean room environment.

[0020] (4) The embodiments of the present invention provide a laser painting method and anti-counterfeiting system based on aluminum-based materials. The pattern structure of the laser painting is controllable and has advantages over inkjet printing, such as good stability and resistance to fading.

[0021] (5) The embodiment of the present invention provides a laser painting method and anti-counterfeiting system based on aluminum-based materials, wherein the structure processed by the laser method can be flexibly anti-counterfeiting encrypted by solution corrosion.

[0022] (6) For the design and implementation of anti-counterfeiting encryption for high value-added goods, the laser painting based on aluminum-based materials and its anti-counterfeiting method and system provided by the embodiment of the present invention provide an excellent solution, which can prevent counterfeiting without affecting the aesthetics of the goods. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a schematic diagram of a laser painting process based on aluminum-based materials and an anti-counterfeiting method thereof, provided in a typical embodiment of the present invention; Figure 2 This is a physical picture of aluminum hydroxide ink provided by a typical embodiment of the present invention; Figure 3 This is a schematic diagram of a laser processing system provided by a typical embodiment of the present invention; Figure 4a 、 Figure 4b This is a schematic diagram of quantitative control of the structure by processing parameters provided in a typical embodiment of the present invention; Figure 5 This is a schematic diagram of processing a large area color block provided by a typical embodiment of the present invention; Figure 6 This is a schematic diagram of preparing a multi-color structural color device provided by a typical embodiment of the present invention; Figure 7 It is a flowchart of information encryption and decryption provided by a typical implementation case of the present invention. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions, and advantages of the present invention more apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Examples of these preferred embodiments are illustrated in the accompanying drawings. The embodiments of the present invention shown in and described with reference to the accompanying drawings are merely exemplary, and the present invention is not limited to these embodiments.

[0026] In a typical embodiment, a laser painting system based on aluminum-based materials and an anti-counterfeiting system thereof include: Glass substrate fixing module: used to transfer the configured ink to the glass substrate through the pipette gun and fix the glass substrate to the laser processing system; Structural forming module: used to focus the laser beam on the interface between the ink and the glass substrate, and through the local photothermal effect of the laser, it can induce the growth and formation of aluminum hydroxide micro-nanostructures on the substrate surface; The image processing module is used to segment and slice the image to be processed and finally generate point cloud data; The color painting quantitative control module is used to control the focused laser beam to perform two-dimensional pattern scanning based on the point cloud data. During the scanning process, the laser exposure time and laser power are controlled to quantitatively control the geometric parameters of the aluminum hydroxide microstructure, and ultimately quantitatively control the structural color presented by the aluminum hydroxide microstructure; The painting processing module is used to remove the glass substrate from the laser processing system, rinse it with deionized water and blow it dry with nitrogen, and finally achieve aluminum-based structural color painting; The anti-counterfeiting module is used to realize encryption of painted information and anti-counterfeiting of labels by using a solution corrosion method.

[0027] In one embodiment, the ink is composed of aluminum nitrate and sodium hydroxide; the specific preparation method of the ink is: Aluminum nitrate nonahydrate and sodium hydroxide solid reagents were accurately weighed according to a molar concentration of 500 mM; The mixed solution is prepared by a graded dissolution method; A stirring bar was added and stirred under constant stirring conditions of a magnetic stirrer for half an hour. After the reaction was complete, the mixture was allowed to stand for one hour. The supernatant was filtered to prepare an aluminum nitrate solution containing sodium ions.

[0028] In one embodiment, the laser processing system includes a half-wave plate, a Glan-Taylor prism, an acousto-optic modulator, a pinhole, a galvanometer, a first lens, a second lens, and a light-emitting diode; wherein a 532 nm laser is initially controlled by passing through a combination of a half-wave plate and a Glan-Taylor prism; the acousto-optic modulator is used for further fine-tuning the laser power; the pinhole is used for spatial filtering of the laser; the galvanometer is used for deflecting the light beam; the first lens and the second lens deflect the light beam to the entrance pupil of the objective lens; and the light-emitting diode is used for illumination during camera observation during the processing process.

[0029] In one embodiment, the image processing module further includes a segmentation module, which is used to first perform grayscale processing on the image to be processed to obtain a grayscale histogram of the entire image, and then divide the entire image into two areas, namely a black area and a white area through global threshold segmentation; the black area is the target object area, and the white area is the background area.

[0030] In one embodiment, the image processing module further includes a slicing module for optimizing the slice file by adjusting the image zoom size and the single-point exposure spacing; wherein the single-point spacing of the slice is set to 500 nm.

[0031] In one embodiment, the anti-counterfeiting module further comprises: A QR code preparation module is used to form a layer of zirconium oxide QR code pattern on the surface of a glass substrate by laser; The QR code hiding module is used to process a layer of aluminum hydroxide pattern on the surface of the zirconia QR code pattern to hide the QR code pattern inside and realize information encryption.

[0032] In a typical implementation case, Figure 1 As shown, a laser painting method based on aluminum-based materials and an anti-counterfeiting method thereof specifically include the following steps: Step 1: Transfer the prepared ink to the glass substrate using a pipette gun, and fix the glass substrate to the laser processing system; Step 2: Focus the laser beam on the interface between the ink and the glass substrate. Through the local photothermal effect of the laser, the aluminum hydroxide micro-nanostructure can be induced to grow on the surface of the glass substrate. Step 3: Segment and slice the image to be processed, and finally generate point cloud data; Step 4: Control the focused laser beam to perform two-dimensional patterned scanning based on the point cloud data. During the scanning process, control the laser exposure time and laser power to quantitatively control the geometric parameters of the aluminum hydroxide microstructure, and ultimately quantitatively control the structural color presented by the aluminum hydroxide microstructure; Step 5: Remove the glass substrate from the laser processing system, rinse it with deionized water, and blow dry it with nitrogen to achieve the final aluminum-based structural color painting. Step 6: Use solution corrosion method to realize encryption of painted information and anti-counterfeiting of labels.

[0033] In order to produce a denser aluminum hydroxide structure, an ink formula consisting of aluminum nitrate solution and sodium hydroxide solid is used. The specific aluminum hydroxide ink is as follows: Figure 2As shown. First, aluminum nitrate nine hydrate and sodium hydroxide solid reagents were accurately weighed according to a molar concentration of 500 mM, and a mixed solution was prepared using a graded dissolution method. After the preparation, a stirrer was added and stirred at a constant speed (300 rpm) on a magnetic stirrer for half an hour. After the reaction was complete, it was allowed to stand for one hour. The supernatant was filtered to prepare an aluminum nitrate solution containing sodium ions to facilitate the formation of aluminum hydroxide precipitation in the later stage. In the laser painting step, the prepared ink was transferred into the PDMS chamber using a pipette, thereby generating a dense aluminum hydroxide structure under photothermal conditions. During the ink sealing process, a polydimethylsiloxane (PDMS) ring frame with a height of approximately 1 mm was adhered to a platinum-coated glass substrate as a reservoir. The aluminum nitrate ink solution was placed in the PDMS reservoir and then sealed by covering it with a second PDMS part to prevent solvent evaporation during the laser printing process.

[0034] In order to achieve high-precision and high-quality structural color laser printing technology, the following laser processing system was built, such as Figure 3 The laser processing system includes a half-wave plate, a Glan-Taylor prism, an acousto-optic modulator, a pinhole, a galvanometer, a first lens, a second lens, and a light-emitting diode. A 532 nm laser is initially controlled by passing through the half-wave plate and the Glan-Taylor prism. The acousto-optic modulator is used to further fine-tune the laser power. The pinhole is used for spatial filtering of the laser. The galvanometer is used to deflect the light beam. The first lens and the second lens deflect the light beam to the entrance pupil of the objective lens. The light-emitting diode is used for illumination during camera observation during the processing process.

[0035] Specifically, the processing substrate, scanning speed, and processing power are three key parameters in the laser processing of samples. Processing was performed on glass, platinum-coated, silicon-coated, and silicon dioxide substrates. It was found that the lines processed on the platinum-coated substrate were dense and did not fall off, and the cost was lower than that of silicon-coated and silicon dioxide substrates. Furthermore, using a 532 nm continuous laser on a platinum-coated substrate with a thickness of 30 nm to 50 nm produced the most stable aluminum hydroxide structure. For single-point processing of aluminum hydroxide, the laser processing power is controlled to be 2.7 mW to 3.9 mW, and the exposure time is between 10 ms and 10 s, which can process points with diameters of 0.8 μm to 4.2 μm; for aluminum hydroxide line processing, the laser processing power is controlled to be 3 mW to 3.9 mW, and the scanning speed is between 10 μm / s and 60 μm / s, which can generate lines with dense structure; for the processing of small aluminum hydroxide blocks, the processing power is controlled to be 2.35 mW to 3.9 mW, the single-point spacing is 400 nm to 600 nm, and the single-point exposure time is between 20 μs and 60 μs, which can process color blocks with a thickness of 250 nm to 650 nm. Figure 4a 、 Figure 4bThe quantitative control of the generated structure during laser processing is demonstrated. By controlling the laser power and exposure time, quantitative control of the single point diameter and color block thickness is achieved respectively. Figure 4a The correspondence between the monotonically increasing exposure time of 2 ms, 4 ms, 8 ms, 16 ms, 32 ms, 64 ms, 128 ms, 256 ms, 512 ms, 1024 ms, and 2048 ms and the single spot diameter at laser processing powers of 3.0 mW and 3.35 mW is described. Figure 4b The corresponding relationship between the monotonically increasing single-point exposure time of 20 μs, 25 μs, 30 μs, 35 μs, 40 μs, 45 μs, 50 μs, 55 μs, and 60 μs and the color block thickness is described under the laser processing power of 3.0 mW and 3.35 mW. Figure 4a and Figure 4b The corresponding relationship between the processing parameters and the generated structure is combined with the phenomenon of coherent superposition of light after reflection on the upper and lower surfaces of the aluminum hydroxide color block. The laser power is controlled to increase from 3.0 mw, 3.1 mw, 3.2 mw, 3.3 mw, 3.4 mw, 3.5 mw, 3.6 mw, and 3.7 mw in sequence, and finally the following is successfully processed. Figure 5 The shown image contains a large 8×7 color block containing multiple colors such as blue, red, purple, orange, yellow, and cyan.

[0036] Specifically, the segmentation process includes: first performing grayscale processing on the image to be processed to obtain a grayscale histogram of the entire image, and then dividing the entire image into two areas, namely a black area and a white area, through global threshold segmentation; the black area is the target object area, and the white area is the background area.

[0037] Specifically, the slicing process involves controlling the laser beam's motion in three-dimensional space to achieve fixed-point processing during the machining process. Traditional two-dimensional images contain only planar information and cannot perform high-precision path planning. Therefore, the two-dimensional image must be converted into a three-dimensional coordinate file recognizable by the controller. During the slicing process, the slicing file can be optimized by adjusting the image scale and the single-point exposure spacing. Considering the relationship between laser machining time and the single-point exposure diameter, the single-point spacing for slicing in the present invention is set to 500 nm. This saves processing time while maintaining the pattern structure.

[0038] Laser painting: By focusing 532 nm continuous light onto a heat-absorbing glass substrate coated with 50 nm platinum, combined with the point cloud data formed by pattern segmentation and slicing, and controlling the specific single-point exposure time (usually between 10 μs and 50 μs) and processing power (usually between 3 mW and 3.9 mW), two-dimensional pattern painting can be achieved. In order to better color the pattern, it is generally necessary to first perform multiple processing to find the corresponding relationship between processing parameters and colors under the same conditions. At the same time, when processing multi-color patterns, it is necessary to ensure that the translation stage cannot move, otherwise the processed patterns will not overlap. For example Figure 6 As shown, Figure 6 A jpg format photo of a flower was selected and the original image was processed to generate corresponding point cloud files for different color parts. Then, specific colors were formed through corresponding processing parameters to prepare multi-color structural color devices.

[0039] like Figure 7 As shown, to achieve effective information encryption and label anti-counterfeiting, a solution corrosion method is employed: by immersing the aluminum hydroxide in a solution, the surface corrodes, revealing the hidden information. In one embodiment, a zirconium oxynitrate solid reagent is precisely weighed to a molar concentration of 500 mM and fully dissolved in deionized water to form a zirconium oxynitrate solution. The zirconium oxynitrate solution is then dripped onto the surface of a platinum-coated glass slide (i.e., a glass substrate) using a pipette. A laser is used to create a localized high-temperature field on the surface of the platinum-coated glass slide to induce the precipitation of zirconium oxide. A computer reads the corresponding QR code point cloud file to control the movement of a galvanometer to form a zirconium oxide QR code pattern. A thin film of aluminum hydroxide is then applied to the zirconium oxide QR code pattern at a power of 3.35 mW using a single-point exposure time of 30 μs, thereby concealing the QR code information and achieving encryption. During post-processing, a 0.1 mol / L sodium hydroxide solution is added to quickly remove the surface aluminum hydroxide layer, revealing the QR code information underneath. Given the varying resistance of different materials to alkaline corrosion, this method can be repeated multiple times. The emergence of this technology can greatly reduce the difficulty of preparing anti-counterfeiting labels, and its application in the commodity field can better protect the rights and interests of merchants and consumers.

[0040] To ensure easier processing and prevent detachment when laser printing aluminum hydroxide structures and for encryption and anti-counterfeiting applications, the cover glass substrate undergoes a series of treatments before platinum coating: First, carefully wipe the glass with an ethanol and isopropyl alcohol solution to remove surface impurities; then, bake it in an oven at 150°C for one hour. After drying and cooling, it is placed in a plasma treatment machine for 8 minutes to enhance surface adhesion. Future attempts will include processing on more substrates, such as ceramic materials and some high-end liquor bottle caps, to expand the commercial application of this technology.

[0041] It should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions of each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A laser painting method based on aluminum-based materials and an anti-counterfeiting method thereof, characterized in that: include: Step 1: Transfer the prepared ink to the glass substrate using a pipette gun, and fix the glass substrate to the laser processing system; Step 2: Focus the laser beam on the interface between the ink and the glass substrate, and induce the growth of aluminum hydroxide micro-nanostructures on the surface of the glass substrate through the local photothermal effect of the laser; Step 3: Segment and slice the image to be processed, and finally generate point cloud data; Step 4: Control the focused laser beam to perform two-dimensional patterned scanning based on the point cloud data. During the scanning process, control the laser exposure time and laser power to quantitatively control the geometric parameters of the aluminum hydroxide microstructure, and ultimately quantitatively control the structural color presented by the aluminum hydroxide microstructure; Step 5: Remove the glass substrate from the laser processing system, rinse it with deionized water, and blow dry it with nitrogen to achieve the final aluminum-based structural color painting. Step 6: Use solution corrosion method to realize encryption of painted information and anti-counterfeiting of labels.

2. The laser painting based on aluminum-based materials and the anti-counterfeiting method thereof according to claim 1, characterized in that: The ink is composed of aluminum nitrate and sodium hydroxide; the specific preparation method of the ink is: Aluminum nitrate nonahydrate and sodium hydroxide solid reagents were accurately weighed according to a molar concentration of 500 mM; The mixed solution is prepared by a graded dissolution method; A stirring bar was added and stirred under constant stirring conditions of a magnetic stirrer for half an hour. After the reaction was complete, the mixture was allowed to stand for one hour. The supernatant was filtered to prepare an aluminum nitrate solution containing sodium ions.

3. The laser painting based on aluminum-based materials and the anti-counterfeiting method thereof according to claim 1, characterized in that: The laser processing system includes a half-wave plate, a Glan Taylor prism, an acousto-optic modulator, a pinhole, a galvanometer, a first lens, a second lens, and a light-emitting diode. The laser passes through the half-wave plate and the Glan Taylor prism combination to initially control the laser power; the acousto-optic modulator is used to further fine-tune the laser power; the pinhole is used for spatial filtering of the laser; the galvanometer is used for deflecting the light beam; the first lens and the second lens deflect the light beam to the entrance pupil of the objective lens; and the light-emitting diode is used for illumination during camera observation during the processing process.

4. The laser painting based on aluminum-based materials and the anti-counterfeiting method thereof according to claim 1, characterized in that: The segmentation process includes: first performing grayscale processing on the image to be processed to obtain the grayscale histogram of the entire image, and then dividing the entire image into two areas, namely the black area and the white area, through global threshold segmentation; the black area is the target object area, and the white area is the background area.

5. The laser painting method based on aluminum-based materials and the anti-counterfeiting method thereof according to claim 1, characterized in that: The slicing process includes: optimizing the slice file by adjusting the image scaling and single-point exposure spacing; wherein the single-point spacing of the slice is set to 500 nm.

6. The laser painting based on aluminum-based materials and the anti-counterfeiting method thereof according to claim 1, characterized in that: The solution etching method is used to achieve encryption of painted information and anti-counterfeiting of labels, specifically comprising: dripping a zirconium oxynitrate solution onto the surface of a glass substrate, focusing a laser on the surface of the glass substrate to generate a local high temperature field to induce the zirconium oxynitrate solution to form a layer of zirconium oxide two-dimensional code pattern, and then dripping the ink onto the surface of the zirconium oxide two-dimensional code pattern to process a layer of aluminum hydroxide pattern on the surface of the zirconium oxide two-dimensional code pattern to hide the zirconium oxide two-dimensional code pattern inside, thereby achieving information encryption.

7. A laser painting system based on aluminum-based materials and its anti-counterfeiting system, characterized in that: include: Glass substrate fixing module: used to transfer the configured ink to the glass substrate through the pipette gun and fix the glass substrate to the laser processing system; Structural forming module: used to focus the laser beam on the interface between the ink and the glass substrate, and induce the growth and formation of aluminum hydroxide micro-nanostructures on the substrate surface through the local photothermal effect of the laser; The image processing module is used to segment and slice the image to be processed and finally generate point cloud data; The color painting quantitative control module is used to control the focused laser beam to perform two-dimensional pattern scanning based on the point cloud data. During the scanning process, the laser exposure time and laser power are controlled to quantitatively control the geometric parameters of the aluminum hydroxide microstructure, and ultimately quantitatively control the structural color presented by the aluminum hydroxide microstructure; The painting processing module is used to remove the glass substrate from the laser processing system, rinse it with deionized water and blow it dry with nitrogen, and finally achieve aluminum-based structural color painting; The anti-counterfeiting module is used to realize encryption of painted information and anti-counterfeiting of labels by using a solution corrosion method.

8. The aluminum-based laser painting and anti-counterfeiting system according to claim 7, characterized in that: The ink is composed of aluminum nitrate and sodium hydroxide; the specific preparation method of the ink is: Aluminum nitrate nonahydrate and sodium hydroxide solid reagents were accurately weighed according to a molar concentration of 500 mM; The mixed solution is prepared by a graded dissolution method; A stirring bar was added and stirred under constant stirring conditions of a magnetic stirrer for half an hour. After the reaction was complete, the mixture was allowed to stand for one hour. The supernatant was filtered to prepare an aluminum nitrate solution containing sodium ions.

9. The laser painting and anti-counterfeiting system based on aluminum-based materials according to claim 7, characterized in that: The laser processing system includes a half-wave plate, a Glan Taylor prism, an acousto-optic modulator, a pinhole, a galvanometer, a first lens, a second lens, and a light-emitting diode. The laser passes through the half-wave plate and the Glan Taylor prism combination to initially control the laser power; the acousto-optic modulator is used to further fine-tune the laser power; the pinhole is used for spatial filtering of the laser; the galvanometer is used for deflecting the light beam; the first lens and the second lens deflect the light beam to the entrance pupil of the objective lens; and the light-emitting diode is used for illumination during camera observation during the processing process.

10. The aluminum-based laser painting and anti-counterfeiting system according to claim 7, characterized in that: The image processing module further includes a segmentation module for performing grayscale processing on the image to be processed to obtain a grayscale histogram of the entire image, and then dividing the entire image into two areas, namely a black area and a white area, through global threshold segmentation; The black area is the target object area, and the white area is the background area.

Images