Information security and anti-counterfeiting method based on random pattern

Abstract

The present application relates to the field of information security and anti-counterfeiting technology, and relates to an information security and anti-counterfeiting method, and relates to a random pattern applied to information security and anti-counterfeiting and a preparation method thereof. The preparation method of the random pattern comprises the following steps: i) printing a polymer ink dot array on a substrate by inkjet printing, curing the dot array, and preparing a microstructure template; ii) spreading a functional material assembly liquid on the surface of the microstructure template, removing the solvent in the functional material assembly liquid, and assembling the functional material to obtain a random pattern in the removal process. The method can realize the generation of a non-reproducible random pattern, which has potential application value in the field of information security and anti-counterfeiting.

Description

Technical Field

[0001] This invention relates to the field of information security and anti-counterfeiting technology, to an information security and anti-counterfeiting method, and to a random pattern applied to information security and anti-counterfeiting and its preparation method. Background Technology

[0002] With the rapid development of information technology, the demand for information security and anti-counterfeiting technologies is constantly increasing, and some such technologies have been proposed and put into practical use. In recent years, scholars have proposed the concept of physical anti-cloning, which utilizes the inherent randomness of the preparation method itself to obtain random results for anti-counterfeiting. The results obtained through this method are unique, like human fingerprints, and can therefore serve as a unique label for verification of the counterfeit item. However, currently reported physical anti-cloning methods typically involve cumbersome preparation processes, hindering their wider application. Therefore, developing simple and flexibly implementable physical anti-cloning methods is of great significance in the fields of information security and anti-counterfeiting. Summary of the Invention

[0003] In view of the shortcomings of existing technologies, the purpose of this invention is to provide a simple, low-cost, flexible, and physically uncopyable anti-counterfeiting method. Another objective of this invention is to provide a random pattern suitable for the above-mentioned anti-counterfeiting method and a method for preparing the same.

[0004] Specifically, the present invention provides the following technical solution:

[0005] An information security and anti-counterfeiting method, the method comprising the following steps:

[0006] 1) Prepare random patterns, including the following steps:

[0007] i) A microstructure template is obtained by printing polymer ink dot matrix onto a substrate through inkjet printing and then solidifying the dot matrix.

[0008] ii) The functional material assembly liquid is spread on the surface of the microstructure template, and the solvent in the functional material assembly liquid is removed. During the removal process, the functional materials are assembled to obtain random patterns.

[0009] 2) The random pattern is used for information security and anti-counterfeiting.

[0010] The present invention also provides a method for preparing random patterns, the method comprising the following steps:

[0011] i) A microstructure template is obtained by printing polymer ink dot matrix onto a substrate through inkjet printing and then solidifying the dot matrix.

[0012] ii) The functional material assembly liquid is spread on the surface of the microstructure template, and the solvent in the functional material assembly liquid is removed. During the removal process, the functional materials are assembled to obtain random patterns.

[0013] The present invention also provides an intrinsic random pattern applicable to the above-mentioned information security and anti-counterfeiting methods, wherein the intrinsic random pattern is prepared by the above-mentioned random pattern preparation method.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] 1) This invention proposes a novel information security and anti-counterfeiting method that combines random patterns with physical anti-cloning technology. This method is a simple, low-cost, flexible, and physically uncopyable anti-counterfeiting method.

[0016] 2) This invention proposes a novel method for preparing random patterns. Specifically, this invention prepares random patterns based on ink printing and assembly materials. The method is simple, low-cost, and the ink dot matrix pattern has good design freedom and aesthetics, making it easy to apply in practice.

[0017] 3) The present invention also provides an intrinsic random pattern prepared by the method of the present invention, which is physically uncopyable and has a good anti-counterfeiting effect, and is particularly suitable for the fields of information security and anti-counterfeiting. Attached Figure Description

[0018] Figure 1 This is an electron microscope image of the random pattern prepared in Example 1 of the present invention.

[0019] Figure 2 This is an electron microscope image of the lattice microstructure template prepared in Example 1 of the present invention.

[0020] Figure 3 This is a schematic diagram of the ICCAS microstructure template used in Embodiment 1 of the present invention.

[0021] Figure 4 This is a low-magnification fluorescent confocal image of the random pattern anti-counterfeiting label prepared in Example 2 of the present invention.

[0022] Figure 5 This is a high-magnification optical microscope image of the random pattern anti-counterfeiting label prepared in Embodiment 2 of the present invention. Detailed Implementation

[0023] As mentioned above, this invention proposes an information security and anti-counterfeiting method, which includes the following steps:

[0024] 1) Prepare random patterns, including the following steps:

[0025] i) A microstructure template is obtained by printing polymer ink dot matrix onto a substrate through inkjet printing and then solidifying the dot matrix.

[0026] ii) The functional material assembly liquid is spread on the surface of the microstructure template, and the solvent in the functional material assembly liquid is removed. During the removal process, the functional materials are assembled to obtain random patterns.

[0027] 2) The random pattern is used for information security and anti-counterfeiting.

[0028] In recent years, with the development of high-performance chips, sensors, and other advanced technologies, the demand for material patterning has been increasing. Consequently, various material patterning technologies have been developed, including wettability induction, microgroove confinement, micropillar-induced self-assembly, microcontact printing, and inkjet printing. Compared to other methods with their cumbersome preparation processes, inkjet printing, with its advantages of simple operation, flexible design, additive manufacturing capabilities, and ease of commercialization, is widely used in fields such as electronic circuits, optoelectronic devices, perovskite arrays, optical displays, and biochips. The inventors discovered that applying inkjet printing patterning methods to physical anti-cloning methods not only achieves the advantages of combining patterning and physical anti-cloning, such as visualization and aesthetics, but also, through further improvements, obtains a random pattern. This random pattern features simple preparation, low cost, flexibility, and physical non-replicability, making it particularly suitable for information security and anti-counterfeiting. It is based on this that this invention was proposed.

[0029] In this invention, the random pattern refers to an intrinsic random pattern caused by uncontrollable factors inherent in the manufacturing process itself, without interference from the external environment.

[0030] In some embodiments of the present invention, in step 2), the random pattern obtained in step 1) is embedded into the product as an anti-counterfeiting mark, and a database of random patterns is established. If the anti-counterfeiting mark on the product can match the corresponding random pattern in the database, it can be determined to be a genuine product; if it cannot match, it is determined to be a counterfeit product.

[0031] In some embodiments of the present invention, step i) specifically includes the following steps:

[0032] i-1) Prepare a hydrophobic substrate;

[0033] i-2) Formulate polymer inks with a viscosity suitable for printing;

[0034] i-3) Print polymer ink dot matrix onto the substrate using inkjet printing;

[0035] i-4) Use ultraviolet light irradiation or heating to solidify the ink dot matrix;

[0036] (i-5) Drying to prepare microstructure templates.

[0037] In some embodiments of the present invention, step i-1) includes directly preparing a hydrophobic substrate, or performing a hydrophobic treatment on the surface of a substrate to obtain a hydrophobic substrate.

[0038] In some embodiments of the present invention, step i-3) includes: designing a printable image using computer graphics software; and printing the prepared polymer ink onto a hydrophobic substrate according to the designed image using printing technology to prepare a polymer ink dot matrix pattern.

[0039] In some embodiments of the present invention, step i-5) includes: heating and drying the solvent in the polymer ink dot matrix to prepare a microstructure template.

[0040] In some embodiments of the present invention, in step i-1), the hydrophobic substrate refers to the substrate having a contact angle greater than 70° with the polymer ink used.

[0041] In some embodiments of the present invention, in step i-1), the hydrophobic substrate may be one of polydimethylsiloxane, polyimide or polyethylene terephthalate.

[0042] In some embodiments of the present invention, in step i-1), the substrate subjected to hydrophobic treatment is one of iron sheet, copper sheet, aluminum sheet, silicon substrate, silicon dioxide substrate, quartz substrate or glass substrate.

[0043] In some embodiments of the present invention, in step i-1), hydrophobic treatment refers to hydrophobic molecular grafting modification of the substrate.

[0044] In some embodiments of the present invention, the hydrophobic molecule may be, but is not limited to, one of n-octyltriethoxysilane, n-decyltrichlorosilane, octadecyltrichlorosilane, or 1H,1H,2H,2H-perfluorodecyltrimethoxysilane.

[0045] In some embodiments of the present invention, the method for grafting and modifying the hydrophobic molecules is gas-phase vacuum treatment or liquid-phase immersion.

[0046] In some embodiments of the present invention, in step i-2), the viscosity of the polymer ink is 1 to 1000 cps, preferably 1 to 50 cps, and is preferably a liquid material that can exist stably at room temperature.

[0047] In some embodiments of the present invention, in step i-2), the polymer ink is a mixed solution composed of a solute and a good solvent.

[0048] For example, the solute may be, but is not limited to, at least one of polyacrylic acid, polyethylene glycol, polyvinyl alcohol, hydroxyethyl methacrylate, or polymethyl methacrylate.

[0049] For example, the good solvent is at least one of water, ethanol, ethylene glycol, toluene, N,N-dimethylformamide or dimethyl sulfoxide.

[0050] For example, the polymer ink is InkOrmo.

[0051] In some embodiments of the present invention, in step i-3), the printable image designed by the computer graphics software is in a format recognizable by the printer.

[0052] In some embodiments of the present invention, in step i-3), the horizontal and vertical spacing of the dots in the polymer ink dot matrix pattern is equal.

[0053] For example, the horizontal and vertical spacing of the points is 40μm to 200μm, preferably 40μm to 160μm.

[0054] For example, the diameter of the point is 10μm to 30μm, preferably 15μm to 25μm.

[0055] In some embodiments of the present invention, in step i-4), the wavelength of the ultraviolet curing light source is 350nm to 420nm.

[0056] In some embodiments of the present invention, in step i-4), the temperature for heating and curing is 30 to 250°C.

[0057] In some embodiments of the present invention, in step i-5), the drying (specifically, heat drying) temperature is 80-250°C.

[0058] In some embodiments of the present invention, step ii) specifically includes the following steps:

[0059] ii-1) The microstructure template is hydrophilically treated;

[0060] ii-2) Prepare the functional material assembly solution;

[0061] ii-3) The functional material assembly liquid is dropped onto the microstructure template, and the upper substrate is placed on the assembly liquid and microstructure template system to form a spatially confined assembly system;

[0062] ii-4) After the solvent in the functional material assembly liquid system evaporates, the upper substrate is peeled off, and a random pattern of functional material assembly is formed on the microstructure template.

[0063] In some embodiments of the present invention, in step ii), the functional material assembly liquid is uniformly spread on the surface of the microstructure template, and then the upper substrate is placed on the assembly liquid and the microstructure template system, allowing the solvent in the assembly liquid to evaporate. During this evaporation process, the liquid film formed by the assembly liquid will gradually spontaneously form continuous liquid bridges with random connections between the microstructures. The functional materials therein will also be deposited and precipitated at the corresponding positions where the continuous liquid bridges exist due to the disappearance of the solvent, thus assembling into a random pattern. This random pattern is physically unreplicable, therefore possessing excellent anti-counterfeiting capabilities.

[0064] In some embodiments of the present invention, in step ii-1), hydrophilic treatment refers to low-temperature plasma treatment of the microstructure template.

[0065] For example, the low-temperature plasma treatment conditions may be, but are not limited to, a power of 5 to 400 W and a time of 5 to 500 s.

[0066] In some embodiments of the present invention, in step ii-2), the functional material in the functional material assembly liquid is a water-dispersible functional material, which may be, but is not limited to, colloidal microspheres, gold / silver nanoparticles, and water-soluble polymers.

[0067] In some embodiments of the present invention, the water-soluble polymer may be PEDOT:PSS and SU-8 photoresist.

[0068] In some embodiments of the present invention, the size of the colloidal microspheres ranges from 10 to 900 nm, and the size of the gold / silver nanoparticles ranges from 2 nm to 50 nm.

[0069] In some embodiments of the present invention, in step ii-2), the functional material assembly liquid is composed of a water-dispersible functional material, a surfactant, and water, wherein the mass content of the water-dispersible functional material is 0.1% to 10%, preferably 0.1% to 4%, and the mass content of the surfactant is 0.05% to 1%, preferably 0.1% to 0.6%.

[0070] In some embodiments of the present invention, the surfactant may be, but is not limited to, anionic surfactants such as sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, stearic acid; amphoteric surfactants such as amino acid type, betaine type, polyacrylamide, lecithin; cationic surfactants such as quaternary ammonium compounds; and nonionic surfactants such as fatty acid sorbitan, fatty acid glycerides, polysorbate, Tween.

[0071] In some embodiments of the present invention, in step ii-3), the upper substrate may be, but is not limited to, one of iron sheet, copper sheet, aluminum sheet, silicon substrate, silicon dioxide substrate, quartz substrate or glass substrate.

[0072] The heterostructure random patterns prepared by the above method also fall within the protection scope of this invention.

[0073] As mentioned above, the present invention also provides a method for preparing random patterns, the method comprising the following steps:

[0074] i) A microstructure template is obtained by printing polymer ink dot matrix onto a substrate through inkjet printing and then solidifying the dot matrix.

[0075] ii) The functional material assembly liquid is spread on the surface of the microstructure template, and the solvent in the functional material assembly liquid is removed. During the removal process, the functional materials are assembled to obtain random patterns.

[0076] In some embodiments of the present invention, steps i) and ii) are the same as steps i) and ii) in the above-described information security and anti-counterfeiting method.

[0077] The present invention also provides an intrinsic random pattern applicable to the aforementioned information security and anti-counterfeiting methods, which is prepared by the above-described random pattern preparation method.

[0078] In some embodiments of the present invention, the random pattern can be a horizontal or vertical broken line type, or a shortest path type.

[0079] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0080] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0081] Example 1

[0082] (1) Select a suitable silicon substrate as the substrate for hydrophobic modification. Its size can be determined as needed. Use chemical vapor grafting of hydrophobic molecules 1H,1H,2H,2H-perfluorodecyltrimethoxysilane to prepare a hydrophobic substrate with an ink contact angle of 80°; (2) Use an oily filter with a pore size of 200nm to filter the commercial ink InkOrmo. Then drop the filtered polymer ink into the inkjet printer cartridge and install a printhead with a droplet size of 1pl; (3) Use the dot matrix parameter design function of the printer to design a dot matrix pattern with a horizontal and vertical spacing of 40μm. Print the polymer ink onto the hydrophobic substrate to obtain a polymer ink droplet dot matrix with a single droplet diameter of 17μm and a horizontal and vertical spacing of 40μm; (4) Use ultraviolet light with a wavelength of 395nm to irradiate for 20 minutes to cure the polymer ink dot matrix; (5) Use the cured dots (6) Place the template on a hot plate at 250°C for 2 hours to dry the solvent in the polymer ink dot matrix and obtain the microstructure template; (7) Perform low-temperature plasma treatment on the microstructure template, with the power set to 120W and the time set to 120s, to obtain a hydrophilic microstructure template; (8) Prepare a polystyrene aqueous dispersion, i.e., a functional material assembly liquid, which contains polystyrene particles with a mass content of 2% and a particle diameter of 270nm, and sodium dodecyl sulfate with a mass content of 0.2%; (9) Take 0.6μl of the polystyrene aqueous dispersion with a pipette and drop it onto the microstructure template; (10) Cover the functional material assembly liquid and the microstructure template system with a clean silicon wafer that has not undergone hydrophilic and hydrophobic treatment to form a spatially confined assembly system; (11) After 1 hour, the solvent in the assembly system completely evaporates, and the covered silicon wafer is peeled off, forming a random pattern on the microstructure substrate.

[0083] Example 2

[0084] (1) Prepare a hydrophobic polydimethylsiloxane substrate (mix the monomer and curing agent in a mass ratio of 10:1, centrifuge to remove air bubbles, level in a square petri dish, and cure in an oven at 80°C for 2 hours), and cut it to the required substrate size; (2) Dye the commercial ink InkOrmo with Rhodamine B, filter the ink with an oily filter with a pore size of 200nm, and then drop the filtered polymer ink into an inkjet printer cartridge and install a printhead with a droplet size of 1pl; (3) Design a dot matrix pattern in the shape of "ICCAS" with a horizontal and vertical spacing of 40μm using Photoshop, print the polymer ink onto the hydrophobic substrate to obtain a polymer ink droplet matrix with a single droplet diameter of 17μm and a horizontal and vertical spacing of 40μm; (4) Irradiate the polymer ink matrix with ultraviolet light at a wavelength of 395nm for 40 minutes to cure the polymer ink matrix; (5) Place the cured dot matrix mold (6) Place the plate on a hot plate at 200°C for 3 hours to dry the solvent in the polymer ink dot matrix and obtain a microstructure template; (7) Perform low-temperature plasma treatment on the microstructure template, with the power set to 100W and the time set to 200s, to obtain a hydrophilic microstructure template; (8) Prepare a fluorescent polystyrene particle aqueous dispersion, i.e., a functional material assembly liquid, which contains commercially available fluorescent polystyrene particles with a mass content of 1% and a particle diameter of 50nm, and sodium dodecyl sulfate with a mass content of 0.2%; (9) Take 0.6μl of the fluorescent polystyrene particle aqueous dispersion with a pipette and drop it onto the microstructure template; (10) Cover the assembly liquid and microstructure template system with a clean glass slide that has not undergone hydrophilic or hydrophobic treatment to form a spatially confined assembly system; (11) After 5 hours, the solvent in the assembly system completely evaporates, and the covered glass slide is peeled off, forming a random pattern on the microstructure substrate.

[0085] Example 3

[0086] (1) Select a suitable quartz substrate as the base for hydrophobic modification. Its size can be determined as needed. Use chemical vapor grafting of hydrophobic molecules 1H,1H,2H,2H-perfluorodecyltrimethoxysilane to prepare a hydrophobic base with an ink contact angle of 80°. (2) Prepare polyacrylic acid ink. Dissolve polyacrylic acid with a molecular weight of 8000 in a mixed solvent of water and ethylene glycol (mass ratio 4:6). The mass ratio of solute to solvent is 3%. Filter the PAA ink using an oily filter with a pore size of 200nm. Then drop the filtered polymer ink into the inkjet printer cartridge and install a printhead with a droplet size of 10pl. (3) Use the dot matrix parameter design function of the printer to design a dot matrix pattern with a horizontal and vertical spacing of 60μm. Print the polymer ink onto the hydrophobic base to obtain a polymer ink droplet matrix with a single droplet diameter of 20μm and a horizontal and vertical spacing of 60μm. (4) Place the polymer ink droplet matrix on a 50℃ hot stage. (5) Keep the polymer ink dot matrix solidified for 10 minutes; (6) Place the solidified dot matrix template on a hot table at 180°C and keep it for 3 hours to dry the solvent in the polymer ink dot matrix and obtain a microstructure template; (7) Perform low-temperature plasma treatment on the microstructure template, with the power set to 100w and the time set to 150s, to obtain a hydrophilic microstructure template; (8) Prepare a PEDOT:PSS aqueous dispersion, i.e., a functional material assembly liquid, which contains 1% PEDOT:PSS (commercially available) and 0.2% sodium dodecyl sulfate; (9) Take 1μl of the PEDOT:PSS aqueous dispersion with a pipette and drop it onto the microstructure template; (10) Cover the assembly liquid and microstructure template system with a clean silicon wafer that has not undergone hydrophilic or hydrophobic treatment to form a spatially confined assembly system; (11) After 2 hours, the solvent in the assembly system completely evaporates, and the covered silicon wafer is peeled off, forming a random pattern on the microstructure substrate.

[0087] Example 4

[0088] (1) Select a suitable glass substrate as the substrate for hydrophobic modification. Its size can be determined as needed. Use chemical vapor grafting of hydrophobic molecules octadecyltrichlorosilane to prepare a hydrophobic substrate with an ink contact angle of 85°. (2) Prepare polyacrylic acid ink. Dissolve polyacrylic acid with a molecular weight of 8000 in a mixed solvent of water and ethylene glycol (mass ratio 4:6). The mass ratio of solute to solvent is 3%. Filter the PAA ink using an oily filter with a pore size of 200nm. Then drop the filtered polymer ink into the inkjet printer cartridge and install a printhead with a droplet size of 10pl. (3) Use Photoshop to design a dot matrix pattern in the shape of the letter "2023" with a horizontal and vertical spacing of 100μm. Print the polymer ink onto the hydrophobic substrate to obtain a single ink droplet with a diameter of 15μm. (4) Place the polymer ink droplet matrix on a 50℃ hot plate for 10 minutes to allow the polymer ink dots to condense. (5) Place the cured dot matrix template on a hot table at 220°C and keep it for 2 hours to dry the solvent in the polymer ink dot matrix and obtain a microstructure template; (6) Perform low-temperature plasma treatment on the microstructure template, with the power set to 150W and the time set to 150s, to obtain a hydrophilic microstructure template; (7) Prepare an aqueous dispersion of gold nanoparticles, i.e., a functional material assembly solution, which contains 1% (10nm) of commercially available gold nanoparticles and 0.3% (3%) of sodium dodecylbenzenesulfonate; (8) Take 1.2μl of the aqueous dispersion of gold nanoparticles with a pipette and drop it onto the microstructure template; (9) Cover the assembly solution and microstructure template system with a clean quartz sheet that has not undergone hydrophilic or hydrophobic treatment to form a spatially confined assembly system; (10) After 1.5 hours, the solvent in the assembly system completely evaporates, and the covered quartz sheet is peeled off, forming a random pattern on the microstructure substrate.

[0089] Example 5

[0090] (1) Purchase polyethylene terephthalate (PET) and determine the required size to serve as a hydrophobic substrate; (2) Prepare PET ink by dissolving PET with a molecular weight of 12,000 in a mixed solvent of water and ethylene glycol (mass ratio 4:6), with a solute-to-solvent mass ratio of 2%. Filter the polymer ink using an oil-based filter with a pore size of 200 nm, then drop the filtered polymer ink into an inkjet printer cartridge and install a printhead with a droplet volume of 1 pl; (3) Using the printer's built-in dot matrix parameter design function, design a dot matrix pattern with a horizontal and vertical spacing of 60 μm. Print the polymer ink onto the hydrophobic substrate to obtain a polymer ink droplet matrix with a single droplet diameter of 10 μm and a horizontal and vertical spacing of 60 μm; (4) Place the polymer ink droplet matrix on a 40°C hot plate for 15 minutes to solidify the polymer ink matrix; (5) Place the solidified polymer ink droplet matrix on a hot plate for 15 minutes to solidify the polymer ink matrix. The prepared dot matrix template was placed on a hot plate at 180°C for 3 hours to dry the solvent in the polymer ink dot matrix and obtain a microstructure template; (6) The microstructure template was subjected to low-temperature plasma treatment with a power of 80W and a time of 180s to obtain a hydrophilic microstructure template; (7) A silver nanoparticle aqueous dispersion, i.e., functional material assembly liquid, was prepared, which contained commercially available silver nanoparticles (10nm) with a mass content of 2% and sodium dodecylbenzenesulfonate with a mass content of 0.2%; (8) 1μl of the silver nanoparticle aqueous dispersion was taken with a pipette and dropped onto the microstructure template; (9) A clean silicon wafer that had not undergone hydrophilic and hydrophobic treatment was covered onto the assembly liquid and microstructure template system to form a spatially confined assembly system; (10) After 2 hours, the solvent in the assembly system was completely evaporated, the covered silicon wafer was peeled off, and a random pattern was formed on the microstructure substrate.

[0091] Example 6

[0092] An information security and anti-counterfeiting method is disclosed, wherein a random pattern is formed using one of the methods in Examples 1-5. This random pattern is used for information security and anti-counterfeiting. Specifically, the obtained random pattern is embedded into a product as an anti-counterfeiting label. A database of random patterns is established, and if the anti-counterfeiting label on the product matches the corresponding random pattern in the database, it can be determined to be genuine; otherwise, it is a counterfeit. Research has found that this anti-counterfeiting random pattern is simple to prepare, highly designable, and physically uncopyable.

[0093] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An information security and anti-counterfeiting method, characterized in that, The method includes the following steps: 1) Prepare random patterns, including the following steps: i) A microstructure template is obtained by printing a polymer ink dot matrix onto a substrate using inkjet printing and then curing the dot matrix. The polymer ink is a mixed solution composed of a solute and a good solvent, wherein the solute is selected from at least one of polyacrylic acid, polyethylene glycol, polyvinyl alcohol, hydroxyethyl methacrylate, or polymethyl methacrylate. ii-1) The microstructure template is hydrophilically treated; ii-2) Prepare the functional material assembly solution; the functional material in the functional material assembly solution is a water-dispersible functional material; the water-dispersible functional material is selected from at least one of colloidal microspheres, gold / silver nanoparticles, and water-soluble polymers; ii-3) The functional material assembly liquid is dropped onto the microstructure template, and the upper substrate is placed on the assembly liquid and microstructure template system to form a spatially confined assembly system; ii-4) After the solvent in the functional material assembly liquid system evaporates, the upper substrate is peeled off, and a random pattern of functional material assembly is formed on the microstructure template; 2) The random pattern is used for information security and anti-counterfeiting.

2. The method as described in claim 1, characterized in that, In step 2), the random pattern obtained in step 1) is embedded into the product as an anti-counterfeiting mark. A database of random patterns is established. If the anti-counterfeiting mark on the product can match the corresponding random pattern in the database, it can be determined to be a genuine product. If they cannot match, it is determined to be a counterfeit product.

3. A method for preparing a random pattern, the method comprising the following steps: i) A microstructure template is obtained by printing a polymer ink dot matrix onto a substrate using inkjet printing and then curing the dot matrix. The polymer ink is a mixed solution composed of a solute and a good solvent, wherein the solute is selected from at least one of polyacrylic acid, polyethylene glycol, polyvinyl alcohol, hydroxyethyl methacrylate, or polymethyl methacrylate. ii-1) The microstructure template is hydrophilically treated; ii-2) Prepare the functional material assembly solution; the functional material in the functional material assembly solution is a water-dispersible functional material; the water-dispersible functional material is selected from at least one of colloidal microspheres, gold / silver nanoparticles, and water-soluble polymers; ii-3) Assemble the functional materials; droplets are placed on the microstructure template, and the upper substrate is placed on the assembly liquid and the microstructure template system to form a spatially confined assembly system; ii-4) After the solvent in the functional material assembly liquid system evaporates, the upper substrate is peeled off, and a random pattern of functional material assembly is formed on the microstructure template.

4. The method according to any one of claims 1-3, characterized in that, Step i) specifically includes the following steps: i-1) Prepare a hydrophobic substrate; i-2) Prepare polymer inks with a viscosity suitable for printing; i-3) Printing polymer ink dot matrix onto the substrate using inkjet printing; i-4) Curing ink dot matrix using ultraviolet light irradiation or heating; (i-5) Drying to prepare microstructure templates.

5. The method as described in claim 4, characterized in that, In step i-1), a hydrophobic substrate refers to a substrate with a contact angle greater than 70° with the polymer ink used.

6. The method as described in claim 4, characterized in that, In step i-2), the polymer ink is a liquid material that can exist stably at room temperature, and the viscosity of the polymer ink is 1~1000cps.

7. The method as described in claim 4, characterized in that, In step i-3), the horizontal and vertical spacing of the dots in the polymer ink dot matrix pattern are equal, and the horizontal and vertical spacing of the dots is 40. m~200 m, the diameter of the point is 10 m ~30 m.

8. The method according to any one of claims 1-3, characterized in that, In step ii-1), hydrophilic treatment refers to low-temperature plasma treatment of the microstructure template.

9. The method according to any one of claims 1-3, characterized in that, In step ii-2), the size range of the colloidal microspheres is 10-900 nm, and the size of the gold / silver nanoparticles is 2 nm-50 nm. And / or, in step ii-2), the functional material assembly liquid is composed of water-dispersible functional material, surfactant and water, wherein the mass content of water-dispersible functional material is 0.1% to 10% and the mass content of surfactant is 0.05% to 1%.

10. An intrinsic random pattern applicable to the information security and anti-counterfeiting method, which is prepared by the method for preparing random patterns as described in any one of claims 1-9.

11. The intrinsic random pattern according to claim 10, characterized in that, The intrinsic random pattern is either a horizontal or vertical broken line type or a shortest path type.

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