A method for fabricating PUF fluorescent anti-counterfeiting patterns based on polymer phase separation

Abstract

This invention discloses a method for fabricating a polymer phase separation (PUF) fluorescent anti-counterfeiting pattern. The method includes preparing a precursor solution ink; preparing a fluorescent micro / nano phase-separated pattern on a substrate surface using spin coating, spraying, or brushing methods; acquiring morphological data of the substrate surface using a portable microscope and performing digital processing to form corresponding PUF encoding information, thus obtaining the PUF pattern. The generation of the micro / nano phase-separated pattern is random, and its corresponding morphological image data is random and unique, which can greatly improve the security of the anti-counterfeiting label. The phase-separated pattern has fingerprint-like characteristics, compatible with existing fingerprint recognition technologies and future artificial intelligence recognition technologies. Furthermore, this strategy is simple to fabricate, requires readily available equipment, has strong versatility, and is suitable for large-scale industrial production.

Description

Technical Field

[0001] This invention relates to the field of physically unclonable functional technology, and in particular to a method for producing a PUF fluorescent anti-counterfeiting pattern based on polymer phase separation. Background Technology

[0002] The rise of information technology has greatly simplified the processes of information generation, storage, sharing, copying, and exchange, fundamentally changing human production and lifestyles and accelerating the progress of world civilization. Today, the world is moving towards the Internet of Things and intelligentization; therefore, developing reliable technologies to protect massive amounts of information data from attacks is crucial. In recent years, various anti-counterfeiting strategies, including watermarks, holograms, barcodes, and QR codes, have developed rapidly to prevent counterfeiting. However, most labels are manufactured through reproducible deterministic processes, making the encoded information vulnerable to cracking and third-party attacks, thus jeopardizing information security.

[0003] Physically unclonable function (PUF) authentication technology has attracted much attention due to its nondeterministic coding and nonreproducible code output. Optical perovskites (PUFs) offer advantages such as low cost and simple manufacturing processes. Complex micro / nano patterns can increase nondeterministic randomness, and the optical signal can further enhance the PUF's functionality. Optical properties can be controlled by the composition and concentration of the luminescent material. Most patterning techniques, such as inkjet printing, photolithography, and nanoimprinting, rely on deterministic top-down fabrication methods, which significantly limit randomness. Bottom-up nondeterministic methods utilize the inherent randomness generated during molecular self-assembly; however, many perovskite synthesis methods are incompatible with bottom-up approaches, hindering the application of perovskites in optical PUFs. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a nondeterministic bottom-up patterning method that utilizes the inherent randomness generated during molecular assembly and phase separation to expand the application of perovskite in optical photopolymer arrays (PUFs). A perovskite precursor solution is mixed with a polymer for in-situ synthesis to create fluorescent phase-separated micro / nano patterns. Utilizing the synergistic effect of spatial confinement and chemical bonding, the perovskite nanocrystals exhibit different states in different polymers, leading to differences in brightness contrast and forming two-phase or multi-phase micro / nano patterns. These patterns are then attached to a substrate using methods such as spin coating, brush coating, air jet printing, transfer printing, micro / nano imprinting, and roll-to-roll patterning. This in-situ preparation eliminates the need for surface modification, expands the fabrication methods, increases internal randomness, and provides greater security. This strategy is simple, low-cost, and the resulting PUF patterns are compatible with artificial intelligence and fingerprint recognition technologies, promoting the industrial application of PUFs.

[0005] The objective of this invention is achieved by providing a method for fabricating a PUF fluorescent anti-counterfeiting pattern based on polymer phase separation, characterized by providing a micro / nano structure pattern with surface fluorescence and random distribution, scanning to obtain pattern information, and performing digital processing to form anti-counterfeiting coding information.

[0006] The method for producing a PUF fluorescent anti-counterfeiting pattern based on polymer phase separation is characterized by the following steps:

[0007] Step S1: Prepare the precursor solution ink;

[0008] Step S2: Print precursor solution ink on the substrate surface;

[0009] Step S3: Evaporate the solvent to achieve random phase separation of the polymer and in-situ preparation of perovskite fluorescent crystals;

[0010] Step S4: Form an anti-counterfeiting label based on the PUF fluorescent pattern.

[0011] The precursor solution ink mentioned in step S1 above includes a perovskite precursor solution and a mixed polymer solution; wherein the perovskite precursor solution includes: 0.001-2 mmol AX and 0.1-3 mmol BX2, wherein element A is an inorganic metal element such as cesium or rubidium, or an organic group such as methylamine or ethylamine, element B is lead, tin, antimony, tellurium, copper or manganese, and halogen X is F, Cl, Br or I.

[0012] The precursor solution ink mentioned in step S1 above includes a perovskite precursor solution and a mixed polymer solution; wherein the polymer includes acrylic homopolymers, polyolefin polymers, block copolymers, etc., and the viscosity of the precursor solution ink is 1cp~20000 cp, and the mass fraction is 0.1%-60%.

[0013] The precursor solution ink mentioned in step S1 above includes a perovskite precursor solution and a mixed polymer solution; the ink solvent used to prepare the perovskite precursor solution and the mixed polymer solution includes dimethyl sulfoxide, ethyl acetate, chlorobenzene, N,N-dimethylformamide, and ionic liquid.

[0014] The substrate selected in step S2 above includes materials such as glass, metal, leather, plastic, and textile fibers.

[0015] In step S2 above, the precursor solution ink is attached to the substrate by methods such as spin coating, brush coating, air jet printing, transfer printing, micro-nano imprinting, and roll-to-roll patterning, and is prepared in situ without the need for surface modification.

[0016] In step S3 above, the perovskite precursor solution in the precursor solution ink is blended with two or more polymers to create a two-phase or multi-phase separated fingerprint pattern. The fluorescence contrast difference between the phases is greater than 2 times, and the size of the phase separated fingerprint pattern can be adjusted in the range of 2 nm to 8000 μm.

[0017] The method for creating PUF fluorescent anti-counterfeiting patterns based on polymer phase separation described in this invention has applications in the fields of random key generation and storage, device authentication, random number generation, and anti-counterfeiting.

[0018] The present invention discloses a method for manufacturing a PUF fluorescent anti-counterfeiting pattern based on polymer phase separation, characterized in that it includes an anti-counterfeiting layer, wherein the anti-counterfeiting layer has a pattern obtained by the method for manufacturing the PUF pattern.

[0019] Specifically, this invention is achieved using the following scheme: a method for creating PUF fluorescent patterns with polymer phase separation and its application in anti-counterfeiting, comprising the following steps:

[0020] Step S1: Prepare the precursor solution ink;

[0021] Step S2: Print precursor solution ink on the substrate surface;

[0022] Step S3: Evaporate the solvent to achieve random phase separation of the polymer and in-situ preparation of perovskite fluorescent crystals;

[0023] Step S4: Form an anti-counterfeiting label based on the PUF fluorescent pattern.

[0024] Furthermore, the substrate may be made of materials such as glass, metal, leather, plastic, or textiles.

[0025] Furthermore, the precursor perovskite solution comprises 0.001-2 mmol AX and 0.1-3 mmol BX2, wherein element A is an inorganic metal element such as cesium or rubidium, or an organic group such as methylamine or ethylamine, element B is lead, tin, antimony, tellurium, copper or manganese, and halogen X is F, Cl, Br or I.

[0026] Furthermore, the polymers include acrylic homopolymers, polyolefin polymers, block copolymers, etc., and the ink viscosity ranges from 1 cp to 20,000 cp.

[0027] Furthermore, the perovskite precursor solution is mixed with the blended polymer solution in a ratio ranging from 1:10 to 1:500.

[0028] Furthermore, a solution of perovskite precursor solution blended with two or more polymers is used to create a two- or multi-phase separated fingerprint pattern, with a fluorescence contrast difference between phases greater than 2, and the size of the phase-separated pattern in the film is adjustable in the range of 2 nm to 8000 μm.

[0029] Furthermore, in step S2, the patterned thin film deposited on the substrate can be prepared by methods including spin coating, brush coating, air jet printing, transfer printing, micro / nano imprinting, and roll-to-roll patterning printing.

[0030] Compared with existing technologies, this invention, through a polymer phase separation PUF fluorescent pattern fabrication method and its application in anti-counterfeiting, combines a nondeterministic bottom-up fluorescent pattern fabrication method with a top-down thin film preparation process. It utilizes the inherent randomness generated during molecular assembly and phase separation, expanding the application of perovskites in optical PUFs. The significant advantages of this invention are its simple fabrication method, readily available equipment, and strong versatility. The multicolor luminescent film constructed from the described perovskite quantum dot / thin film system adheres to rigid materials such as glass and metals, making it suitable for large-scale industrial production. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the preparation process of a polymer phase-separated PUF fluorescent pattern fabrication method according to the present invention;

[0032] Figure 2 This is a schematic diagram of the thin film preparation process;

[0033] Figure 3 The spectrum intensity diagram of the perovskite precursor solution mixed with the polymer;

[0034] Figure 4 Image of the physical characteristics of a polymer two-phase separation pattern;

[0035] Figure 5 Physical feature images of two-phase or multi-phase separation patterns formed by mixing different polymer ratios;

[0036] Figure 6 It is a 64×64 PUF pattern. Detailed Implementation

[0037] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments.

[0038] This invention provides a method for creating a polymer phase-separated PUF fluorescent anti-counterfeiting pattern, see [link to relevant documentation]. Figure 1 This includes the following steps:

[0039] Step S1: Prepare the precursor solution ink;

[0040] Step S2: Print precursor solution ink on the substrate surface;

[0041] Step S3: Evaporate the solvent to achieve random phase separation of the polymer and in-situ preparation of perovskite fluorescent crystals;

[0042] Step S4: Form an anti-counterfeiting label based on the PUF fluorescent pattern.

[0043] In some embodiments of the present invention, 0.001-2 mmol of one of RbBr, chloroethylamine, and methyl bromide, and 0.01-3 mmol of PbBr2, PbCl2, and MnBr2 are dissolved in an organic solvent, mixed, stirred, and heated for 6 h to obtain a perovskite precursor solution.

[0044] In some embodiments of the present invention, the film is attached to the substrate and annealed for 5-60 min at an annealing temperature of 20-100°C to remove excess solvent remaining on the surface.

[0045] In some embodiments of the present invention, the substrate is selected from at least one of glass, metal, leather, plastic, and fibrous textile materials.

[0046] In step S2, the patterned thin film deposited on the substrate 120 is prepared by a printing method including spin coating, spraying with a sprayer 100, brushing with a brush 110, air jet printing, transfer printing, micro / nano imprinting, and roll-to-roll patterning. Figure 2 This is a schematic diagram of part of the process.

[0047] In this embodiment, by utilizing the phase separation morphology of blends such as acrylic homopolymers, polyolefin polymers, and block copolymers, the micro / nano pattern size of the thin film can be adjusted within the range of 2 nm to 8000 μm. Figure 3 This is a spectral intensity diagram of a perovskite precursor solution mixed with a polymer. Different types of polymers crystallize differently in the perovskite precursor, resulting in differences in brightness contrast. Figure 4 These are microscopic images of micro / nano patterns. In the image, 130 represents the phase with high fluorescence intensity, and 140 represents the phase with low fluorescence intensity. Figure 5 These are microscopic images of thin films mixed with different types of polymers in varying proportions, exhibiting a rich variety of patterns.

[0048] In this embodiment, an image is obtained by scanning with a portable fluorescence microscope. The PUF is divided into 64×64 small units, and then pixel points are extracted to obtain the corresponding RGB values. A global search algorithm is used to find the optimal data threshold, and a binary coarse-grained coding algorithm is used to process the image matrix and map it to {0, 1}. The coding capacity of this binary array is 2^32. 4096 After final processing, the corresponding PUF encoded information is generated, resulting in, as shown below. Figure 6 PUF pattern.

[0049] In this embodiment, the key-to-key Hamming distance explores the difference in binary strings formed between two PUF units, i.e., subarrays. If the two strings are unrelated and independent, the key-to-key Hamming distance is 0.5. The fit is verified by Gaussian curves, which meets the requirements of an ideal PUF.

[0050] The invention will be described in more detail below with reference to specific embodiments. These embodiments are given for illustrative purposes and should not be construed as limiting the scope of the invention.

[0051] Example 1

[0052] A method for fabricating a PUF fluorescent anti-counterfeiting pattern based on polymer phase separation, comprising the following steps:

[0053] 1) Dissolve 0.03 mmol of RbBr and 0.05 mmol of PbBr2 in dimethyl sulfoxide, heat and stir at 80 °C for 3 h, and filter through a 0.22 μm organic nylon 66 filter to obtain a perovskite solution.

[0054] 2) Dissolve 120 mg of polyvinylidene fluoride and 80 mg of polyvinylpyrrolidone in dimethyl sulfoxide. After the polymer is completely dissolved, mix and add to the perovskite solution prepared in step 1). Heat at 50 °C for 1 h, and filter with a 0.45 μm organic nylon 66 filter to obtain the precursor solution.

[0055] 3) The prepared precursor solution is brushed onto the substrate, annealed at 40°C to remove excess solvent from the substrate, and the micro-nano phase separation pattern is obtained by scanning with a portable microscope. After binarization processing, the PUF anti-counterfeiting label is generated.

[0056] Example 2

[0057] A method for fabricating a PUF fluorescent anti-counterfeiting pattern based on polymer phase separation, comprising the following steps:

[0058] 1) Dissolve 1.5 mmol of chloroethylamine and 1.5 mmol of PbCl2 in ethyl acetate, heat and stir at 80°C for 3 h, and filter through a 0.22 μm organic nylon 66 filter to obtain a perovskite solution.

[0059] 2) Dissolve 70 mg of polyvinylidene fluoride and 130 mg of polymethyl methacrylate in ethyl acetate. After the polymer is completely dissolved, mix and add the perovskite solution prepared in step 1). Heat at 80 °C for 2 h, and filter with a 0.45 μm organic nylon 66 filter to obtain the precursor solution.

[0060] 3) The precursor solution obtained in step 2) is spin-coated onto the substrate at 4500 r / min for 50 s, annealed at 70℃ to remove excess solvent from the substrate, and the micro-nano phase separation pattern is obtained by scanning with a portable microscope. After binarization processing, the PUF anti-counterfeiting label is generated.

[0061] Example 3

[0062] A method for fabricating a PUF fluorescent anti-counterfeiting pattern based on polymer phase separation, comprising the following steps:

[0063] 1) Dissolve 1.5 mmol of methyl bromide and 2 mmol of MnBr2 in N,N-dimethylformamide, heat and stir at 60°C for 3 h, and filter through a 0.22 μm organic nylon 66 filter to obtain a perovskite solution.

[0064] 2) Dissolve 160 mg of polystyrene and 40 mg of polymethyl methacrylate in N,N-dimethylformamide. After the polymer is completely dissolved, mix and add the perovskite solution prepared in step 1). Heat at 80°C for 2 hours and filter with a 0.45 μm organic nylon 66 filter to obtain the precursor solution.

[0065] 3) The precursor solution obtained in step 2) is sprayed onto the substrate as fine droplets using a spray gun, annealed at 80°C to remove excess solvent from the substrate, and the micro-nano phase separation pattern is obtained by scanning with a portable microscope. After binarization processing, the PUF anti-counterfeiting label is generated.

Claims

1. A method for making a polymer phase separation based PUF fluorescent anti-counterfeiting pattern, characterized in that, It provides micro / nano structure patterns with surface fluorescence and random distribution, scans to obtain pattern information, and performs digital processing to form anti-counterfeiting code information; Specifically, the steps include the following: Step S1: Prepare precursor solution ink, wherein the precursor solution ink includes perovskite precursor solution and mixed polymer solution; Step S2: Print precursor solution ink on the substrate surface; Step S3: Evaporate the solvent, blend the perovskite precursor solution in the precursor solution ink with two polymers to achieve random phase separation of the polymers and in-situ preparation of perovskite fluorescent crystals, and create a two-phase separated fingerprint pattern. The fluorescence contrast difference between the phases is greater than 2 times, and the size of the phase separated fingerprint pattern can be adjusted in the range of 2 nm to 8000 μm. Step S4: Form an anti-counterfeiting label based on a PUF fluorescent pattern; The perovskite precursor solution comprises: 0.001-2 mmol AX and 0.1-3 mmol BX2, wherein element A is the inorganic metal element rubidium, or the organic group methylamine or ethylamine, element B is lead or manganese, and halogen X is Cl or Br; The polymer in the mixed polymer solution is polyvinylidene fluoride and polyvinylpyrrolidone, or polyvinylidene fluoride and polymethyl methacrylate, or polystyrene and polymethyl methacrylate. The viscosity of the precursor solution ink is from 1 cp to 20,000 cp. The organic solvent used to prepare the perovskite precursor solution is the same as the organic solvent used to prepare the mixed polymer solution, and is selected from N,N-dimethylformamide, dimethyl sulfoxide, or ethyl acetate. In step S2, the precursor solution ink is attached to the substrate by spin coating, brush coating, scraping coating, air jet printing, transfer printing, micro / nano imprinting, or roll-to-roll patterning printing methods without the need for surface modification.

2. The application of the method for producing PUF fluorescent anti-counterfeiting patterns based on polymer phase separation as described in claim 1 in the fields of random key generation and storage, device authentication, random number generation, or anti-counterfeiting.

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