Stretchable intelligent anti-counterfeiting light sticker and preparation method thereof

Abstract

The application discloses a stretchable intelligent anti-fake light sticker and a preparation method thereof. The stretchable intelligent anti-fake light sticker comprises, from bottom to top, a substrate layer, a bottom electrode layer, a light-emitting active layer and a pattern electrode layer which are stacked in sequence. In an initial state, the pattern electrode layer is in an insulating state, and its conductive capacity needs to be activated by pressing or stretching. After the activated light sticker is connected with an external power supply, the light sticker can emit light to display a preset pattern, realizing an interactive anti-fake effect. The stretchable intelligent anti-fake light sticker has the characteristics of lightness, thinness, flexibility, good stretching performance, stable display effect, strong interactivity and difficulty in counterfeiting, and can achieve a higher level of anti-fake effect and improve the technological sense and added value of products.

Description

Technical Field

[0001] This invention belongs to the field of anti-counterfeiting label technology, and relates to intelligent anti-counterfeiting optical stickers, specifically a stretchable intelligent anti-counterfeiting optical sticker and its preparation method. Background Technology

[0002] With the continuous progress of society and the rapid development of the consumer market, various branded products are constantly emerging, greatly enriching people's lives. However, counterfeit and shoddy products are rampant in the market, and despite repeated crackdowns, they are difficult to eradicate, seriously disrupting the normal market order and causing enormous damage to consumers' economic interests and health. Against this backdrop, the importance of anti-counterfeiting technology has become increasingly prominent, becoming one of the key means to ensure the healthy operation of the market.

[0003] Among numerous anti-counterfeiting technologies, smart anti-counterfeiting labels have garnered widespread attention from academia and industry due to their low power consumption, fast response, ease of use, and significant anti-counterfeiting effects. The development of smart anti-counterfeiting labels involves the integration of technologies from multiple disciplines, such as materials science, electronic information technology, chemistry, computer science, and biotechnology. Common smart anti-counterfeiting labels include radio frequency identification (RFID) tags, QR code tags, and laser holographic tags. However, these smart anti-counterfeiting labels are easily broken or deformed when subjected to mechanical tension or pressure, leading to the loss or unreadable of anti-counterfeiting information. Furthermore, they typically provide only single, fixed information, have relatively limited interactivity, and are easily counterfeited. These issues significantly limit their application scope. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a stretchable intelligent anti-counterfeiting optical sticker and its preparation method. After connecting the positive and negative terminals of an external power supply to the bottom electrode layer and the pattern electrode layer respectively, the optical sticker can irreversibly emit light and display a preset pattern by stretching or pressing, thereby determining whether the product has been inspected or used. This can effectively enhance the technological feel and added value of the product and curb the circulation of counterfeit goods.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A stretchable smart anti-counterfeiting optical sticker includes a base layer, a bottom electrode layer, a light-emitting active layer and a pattern electrode layer stacked from bottom to top.

[0007] The substrate layer is a stretchable flexible polydimethylsiloxane film;

[0008] The raw materials for the bottom electrode layer include an aqueous solution of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, pentanediol, N,N-dimethylacetamide, and polyethylene glycol octylphenyl ether in a volume ratio of (85-95):(2-7):(2-7):1; wherein the mass fraction of the aqueous solution of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid is 1.3%.

[0009] The raw materials for the luminescent active layer include a mixed solution obtained by mixing a 5 mg / ml tetrahydrofuran solution of the conjugated polymer Super yellow, a 10 mg / ml cyclohexanone solution of lithium bis(trifluoromethanesulfonylimide) and a 10 mg / ml cyclohexanone solution of polyethylene oxide, measured in a volume ratio of (85-90):2:(8-13), and polyethylene glycol octylphenyl ether in a mass ratio of 1:1 with the mixed solution.

[0010] The raw material for the patterned electrode layer is gallium indium eutectic alloy liquid metal ink. The raw material for the gallium indium eutectic alloy liquid metal ink includes gallium indium eutectic alloy liquid metal and PEO solution in a mass ratio of 3:1. The PEO solution is a mixed solution prepared by polyethylene oxide, disodium lauryl sulfosuccinate monoester and deionized water in a mass ratio of (35-45):1:1000.

[0011] Preferably, the gallium mass fraction in the gallium-indium eutectic alloy liquid metal is 75.5%, and the indium mass fraction is 24.5%.

[0012] This invention also protects a method for preparing the stretchable smart anti-counterfeiting optical sticker as described above, comprising the following steps:

[0013] Step 1: Cut the polydimethylsiloxane film into sheets with an area of ​​20mm×20mm and a thickness of 3mm to obtain the base layer of the stretchable smart anti-counterfeiting photoadhesive.

[0014] Step 2: Mix poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid aqueous solution, pentanediol, N,N-dimethylacetamide and polyethylene glycol octylphenyl ether in a volume ratio of (85-95):(2-7):(2-7):1 and stir thoroughly to prepare a mixed solution. Spin coat the solution onto the substrate layer in Step 1. After spin coating, perform annealing treatment and then acid treatment on the upper surface of the film to obtain the bottom electrode layer of the stretchable smart anti-counterfeiting photofilm.

[0015] Step 3: Take a mixed solution with a volume ratio of (85-90):2:(8-13) of 5 mg / ml of the conjugated polymer Superyellow tetrahydrofuran solution, 10 mg / ml of the lithium bis(trifluoromethanesulfonylimide)cyclohexanone solution, and 10 mg / ml of the polyethylene oxide cyclohexanone solution. Take the mixed solution and polyethylene glycol octylphenyl ether at a mass ratio of 1:1 and mix them thoroughly to prepare a luminescent blend. Spin-coat the luminescent blend onto the bottom electrode layer in Step 2. After spin-coating, perform annealing treatment to obtain the luminescent active layer of the stretchable smart anti-counterfeiting photosheet.

[0016] Step 4: Mix the treated gallium-indium eutectic alloy liquid metal with PEO solution at a mass ratio of 3:1 and stir evenly to obtain liquid metal ink; print the liquid metal ink onto the luminescent active layer prepared in step 3 by screen printing, and dry at room temperature to obtain the pattern electrode layer of the stretchable smart anti-counterfeiting photoadhesive.

[0017] Preferably, the acid treatment in step two involves dripping benzoic acid to completely wet the film surface, acting at room temperature for 15 minutes, then removing excess benzoic acid from the surface, and allowing it to dry naturally at room temperature.

[0018] The acid treatment was repeated three times.

[0019] Preferably, the spin coating in steps two and three is performed at a rotation speed of 1000-1300 rpm and a spin coating time of 30-40 s;

[0020] The annealing conditions are annealing at 100-120℃ for 10-20 minutes.

[0021] Preferably, the thorough stirring described in steps two and three is magnetic stirring for 6 to 12 hours;

[0022] The stirring described in step four is magnetic stirring for 1 to 2 hours.

[0023] Preferably, the pretreatment method for the gallium-indium eutectic alloy liquid metal in step four is to perform ultrasonic treatment with isopropanol followed by centrifugation; the ultrasonic treatment power is 300W, the time is 1-2 min, the centrifugation speed is 1500 rpm, and the time is 2-3 min.

[0024] Preferably, the screen printing in step four uses a printing plate with a mesh count of 200-250 l / in, a screen spacing of 3-5 mm, a squeegee angle of 70°, a printing pressure of 0.3-0.45 MPa, and a printing speed of 10 cm / s.

[0025] Compared with the prior art, the present invention has the following technical effects:

[0026] This invention uses liquid gallium indium eutectic alloy as the patterned electrode layer. The luminescent pattern shape is designed according to specific requirements. The patterned liquid metal particles are not conductive because they consist of a core-shell structure with a non-conductive gallium oxide shell and a liquid gallium indium alloy core. The particles are isolated by an insulating oxide film, resulting in overall non-conductivity. Pressing or stretching is required to break the non-conductive gallium oxide shell, releasing the conductive liquid gallium indium alloy core and forming a conductive path. After connecting the positive and negative terminals of an external power supply to the bottom electrode layer and the patterned electrode layer respectively, the light-emitting pattern is... The organic light-emitting layer located between these two forms an electroluminescent effect. When a positive voltage is applied, electrons move from the cathode to the anode, while holes move from the anode to the cathode in the opposite direction. These charges meet and recombine in the light-emitting layer, and the released energy is emitted in the form of light, which can emit light to display a preset pattern. Once the conductivity of the pattern electrode layer is activated, it cannot be restored to its original insulating state. Once the photoadhesive has been checked and verified for authenticity, it cannot be reset or modified. Based on this characteristic, it can be determined whether the product has been checked or used. Generally, it is difficult for counterfeiters to accurately replicate this physical triggering mechanism.

[0027] This invention provides a stretchable smart anti-counterfeiting optical sticker with excellent stretchability. The base layer is made of a stretchable flexible polydimethylsiloxane film. The bottom electrode layer and the luminescent active layer also possess excellent stretchability due to the introduction of the plasticizer polyethylene glycol octylphenyl ether, which increases the free volume inside the film and weakens the inter-polymer chain forces. The liquid metal used in the patterned electrode layer combines the conductivity of metal and the fluidity of liquid, thus also exhibiting excellent stretchability. Each layer structure has good stretchability, and the final smart anti-counterfeiting optical sticker can meet the stretchability requirements in various application scenarios.

[0028] The stretchable smart anti-counterfeiting optical sticker of the present invention has the characteristics of being stretchable, thin and flexible, having a stable display effect, and being difficult to counterfeit. When used in the field of packaging anti-counterfeiting, it can effectively enhance the technological feel and added value of products, curb the circulation of counterfeit goods, and better protect the rights and interests of consumers. Attached Figure Description

[0029] Figure 1 This is a structural diagram of a stretchable smart anti-counterfeiting optical sticker;

[0030] Figure 2 It is a screen printing plate design;

[0031] Figure 3 This is an example image of the use of stretchable smart anti-counterfeiting optical stickers;

[0032] Figure 4 This is a schematic diagram illustrating the working state of the stretchable smart anti-counterfeiting optical sticker;

[0033] Wherein: 1-substrate layer, 2-bottom electrode layer, 3-luminescent active layer, 4-patterned electrode layer. Detailed Implementation

[0034] The specific content of the present invention will be further explained in detail below with reference to the embodiments.

[0035] The average molecular weight of polyethylene glycol octylphenyl ether used in the following examples is 647;

[0036] The average molecular weight of the conjugated polymer Super yellow used is greater than 400,000.

[0037] The average molecular weight of the polyethylene oxide used is 1,000,000.

[0038] The stretchable flexible polydimethylsiloxane film used was prepared using BIOFOUNT (brand) Dow Corning DC184 reagent. Dow Corning DC184 is a two-component kit consisting of liquid components A and B, including PDMS components and a curing agent. The specific preparation method of the stretchable flexible polydimethylsiloxane film includes: completely mixing the polydimethylsiloxane (PDMS) basic component and the curing agent at a weight ratio of 10:1, stirring thoroughly, pouring into a glass dish, allowing it to stand and level, and degas, and drying it in an oven at 80°C for 60 min to obtain solid polydimethylsiloxane. This solid polydimethylsiloxane was then subjected to low-temperature oxygen plasma treatment at a power of 30 W for 90 s.

[0039] like Figures 1 to 4 As shown, this embodiment provides a stretchable smart anti-counterfeiting optical sticker, which includes a base layer 1, a bottom electrode layer 2, a light-emitting active layer 3, and a pattern electrode layer 4 stacked sequentially from bottom to top. After connecting the positive and negative terminals of an external power supply to the bottom electrode layer 2 and the pattern electrode layer 4 respectively, pressing or stretching causes the non-conductive gallium oxide shell of the pattern electrode layer 4 to break, releasing a conductive liquid gallium indium alloy core to form a conductive path, which forms an electroluminescent effect with the light-emitting active layer 3 located between the two, and can emit light to display a preset pattern.

[0040] The following is a detailed embodiment of the preparation method of the stretchable smart anti-counterfeiting optical sticker of the present invention:

[0041] Example 1:

[0042] A method for preparing a stretchable smart anti-counterfeiting optical sticker, specifically implemented according to the following steps:

[0043] Step 1: Cut the polydimethylsiloxane film into sheets with an area of ​​20mm×20mm and a thickness of 3mm to obtain the base layer 1 of the stretchable smart anti-counterfeiting photoadhesive.

[0044] Step 2: Mix 9 ml of 1.3% (w / w) poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid aqueous solution, 0.45 ml of pentanediol, 0.45 ml of N,N-dimethylacetamide, and 0.1 ml of polyethylene glycol octylphenyl ether at room temperature and stir for 9 h to prepare a mixed solution. Spin-coat the prepared mixed solution onto the substrate layer from Step 1 at a spin speed of 1000 rpm for 40 s. After spin-coating, anneal at 120 °C for 15 min.

[0045] Benzoic acid was drop-coated onto the annealed film surface to completely wet the film surface. The film was then treated at room temperature for 15 minutes. Then, excess benzoic acid was removed from the surface and the film was allowed to dry naturally at room temperature. The benzoic acid treatment was repeated three times to obtain the bottom electrode layer 2 of the stretchable smart anti-counterfeiting photofilm.

[0046] Step 3: Measure 8.5 ml of a 5 mg / ml tetrahydrofuran solution of the conjugated polymer Super yellow, 0.2 ml of a 10 mg / ml cyclohexanone solution of lithium bis(trifluoromethanesulfonylimide) and 1.3 ml of a 10 mg / ml cyclohexanone solution of polyethylene oxide to obtain a mixed solution. Then, mix 5 g of the mixed solution with 5 g of polyethylene glycol octylphenyl ether and stir at room temperature for 12 h to prepare a luminescent blend. Spin-coat the luminescent blend onto the bottom electrode layer 2 in Step 2 at a spin speed of 1300 rpm for 30 s. After spin-coating, anneal at 120℃ for 10 min to obtain the luminescent active layer 3 of the stretchable smart anti-counterfeiting photosheet.

[0047] Step 4: Place 3g of gallium-indium eutectic alloy with a mass fraction of 75.5% gallium and 24.5% indium and 7g of isopropanol into a beaker and perform ultrasonic centrifugation. The ultrasonic power is 300W and the time is 2min. The centrifugation speed is 1500rpm and the time is 3min. After that, pour off the supernatant to obtain the liquid metal precipitate of gallium-indium eutectic alloy at the bottom.

[0048] Mix 0.4g polyethylene oxide, 0.01g disodium lauryl sulfosuccinate monoester and 10g deionized water to obtain a PEO solution; mix 3g liquid metal precipitate and 1g PEO solution and stir evenly to obtain liquid metal ink.

[0049] Create images containing pattern information, such as Figure 2 A screen printing plate with a mesh count of 250 l / in is used as shown. Liquid metallic ink is printed onto the luminescent active layer 3 prepared in step three using screen printing equipment at a screen spacing of 3 mm, a printing pressure of 0.3 MPa, a squeegee angle of 70°, and a printing speed of 10 cm / s. After drying at room temperature, the pattern electrode layer of the stretchable smart anti-counterfeiting photoadhesive is obtained, ultimately forming the stretchable smart anti-counterfeiting photoadhesive, with the structure as shown.Figure 1 As shown in the image. When affixed to the product packaging, and the positive and negative terminals of the external power supply are connected to the bottom electrode layer and the pattern electrode layer respectively, it serves both as an anti-counterfeiting measure and to indicate product information. An example of its use is shown in the image. Figure 3 As shown in the diagram, the working process is as follows: Figure 4 As shown.

[0050] The power supply can be integrated with the stretchable smart anti-counterfeiting light sticker, in which case the label will continuously emit light for a certain period of time after being pressed. Alternatively, it can be set separately through the connection port, so that the light will stop when the power is turned off and will emit light directly when the power is turned on again.

[0051] Example 2:

[0052] A method for preparing a stretchable smart anti-counterfeiting optical sticker, specifically implemented according to the following steps:

[0053] Step 1: Cut the polydimethylsiloxane film into sheets with an area of ​​20mm×20mm and a thickness of 3mm to obtain the base layer 1 of the stretchable smart anti-counterfeiting photoadhesive.

[0054] Step 2: Mix 8.5 ml of 1.3% (w / w) poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid aqueous solution, 0.7 ml of pentanediol, 0.7 ml of N,N-dimethylacetamide, and 0.1 ml of polyethylene glycol octylphenyl ether at room temperature and stir for 6 h to prepare a mixed solution. Spin-coat the prepared mixed solution onto the substrate layer in Step 1 at a spin speed of 1100 rpm for 35 s. After spin-coating, anneal at 100 °C for 20 min.

[0055] Benzoic acid was drop-coated onto the annealed film surface to completely wet the film surface. The film was then treated at room temperature for 15 minutes. Then, excess benzoic acid was removed from the surface and the film was allowed to dry naturally at room temperature. The benzoic acid treatment was repeated three times to obtain the bottom electrode layer 2 of the stretchable smart anti-counterfeiting photofilm.

[0056] Step 3: Take 9 ml of a 5 mg / ml tetrahydrofuran solution of the conjugated polymer Super yellow, 0.2 ml of a 10 mg / ml cyclohexanone solution of lithium bis(trifluoromethanesulfonylimide) and 0.8 ml of a 10 mg / ml cyclohexanone solution of polyethylene oxide, mix them to obtain a mixed solution, then mix 5 g of the mixed solution with 5 g of polyethylene glycol octylphenyl ether and stir at room temperature for 6 h to prepare a luminescent blend. Spin-coat the luminescent blend onto the bottom electrode layer 2 in Step 2 at a spin speed of 1000 rpm for 40 s. After spin-coating, anneal at 100℃ for 20 min to obtain the luminescent active layer 3 of the stretchable smart anti-counterfeiting photosheet.

[0057] Step 4: Place 2g of gallium-indium eutectic alloy with a mass fraction of 75.5% gallium and 24.5% indium and 8g of isopropanol into a beaker and perform ultrasonic centrifugation. The ultrasonic power is 300W and the time is 1min. The centrifugation speed is 1500rpm and the time is 2min. After that, discard the supernatant to obtain the liquid metal precipitate of gallium-indium eutectic alloy at the bottom.

[0058] Mix 0.35g polyethylene oxide, 0.01g disodium lauryl sulfosuccinate monoester and 10g deionized water to obtain a PEO solution; mix 3g liquid metal precipitate with 1g PEO solution and stir evenly to obtain liquid metal ink.

[0059] Create images containing pattern information, such as Figure 2 A screen printing plate with a mesh count of 200 l / in is used as shown. Liquid metallic ink is printed onto the luminescent active layer 3 prepared in step three using screen printing equipment at a screen spacing of 5 mm, a printing pressure of 0.45 MPa, a squeegee angle of 70°, and a printing speed of 10 cm / s. After drying at room temperature, the pattern electrode layer of the stretchable smart anti-counterfeiting photoadhesive is obtained, ultimately forming the stretchable smart anti-counterfeiting photoadhesive, with the structure as shown. Figure 1 As shown.

[0060] Example 3:

[0061] A method for preparing a stretchable smart anti-counterfeiting optical sticker, specifically implemented according to the following steps:

[0062] Step 1: Cut the polydimethylsiloxane film into sheets with an area of ​​20mm×20mm and a thickness of 3mm to obtain the base layer 1 of the stretchable smart anti-counterfeiting photoadhesive.

[0063] Step 2: Mix 9.5 ml of 1.3% (w / w) poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid aqueous solution, 0.2 ml of pentanediol, 0.2 ml of N,N-dimethylacetamide, and 0.1 ml of polyethylene glycol octylphenyl ether at room temperature and stir for 12 h to prepare a mixed solution. Spin-coat the prepared mixed solution onto the substrate layer in Step 1 at a spin speed of 1300 rpm for 30 s. After spin-coating, anneal at 110 °C for 10 min.

[0064] Benzoic acid was drop-coated onto the annealed film surface to completely wet the film surface. The film was then treated at room temperature for 15 minutes. Then, excess benzoic acid was removed from the surface and the film was allowed to dry naturally at room temperature. The benzoic acid treatment was repeated three times to obtain the bottom electrode layer 2 of the stretchable smart anti-counterfeiting photofilm.

[0065] Step 3: Measure 8.8 ml of a 5 mg / ml tetrahydrofuran solution of the conjugated polymer Super yellow, 0.2 ml of a 10 mg / ml cyclohexanone solution of lithium bis(trifluoromethanesulfonylimide) and 1 ml of a 10 mg / ml cyclohexanone solution of polyethylene oxide to obtain a mixed solution. Then, mix 5 g of the mixed solution with 5 g of polyethylene glycol octylphenyl ether and stir at room temperature for 10 h to prepare a luminescent blend. Spin-coat the luminescent blend onto the bottom electrode layer 2 in Step 2 at a spin speed of 1100 rpm for 35 s. After spin-coating, anneal at 110℃ for 15 min to obtain the luminescent active layer 3 of the stretchable smart anti-counterfeiting photosheet.

[0066] Step 4: Place 2.5g of gallium-indium eutectic alloy (75.5% gallium by mass, 24.5% indium by mass) and 7.5g of isopropanol into a beaker and perform ultrasonic centrifugation. The ultrasonic power is 300W for 2 minutes, the centrifugation speed is 1500rpm for 3 minutes, and then the supernatant is discarded to obtain the liquid metal precipitate of gallium-indium eutectic alloy at the bottom.

[0067] Mix 0.45g polyethylene oxide, 0.01g disodium lauryl sulfosuccinate and 10g deionized water to obtain a PEO solution; mix 3g liquid metal precipitate and 1g PEO solution and stir evenly to obtain liquid metal ink.

[0068] Create images containing pattern information, such as Figure 2 A screen printing plate with a mesh count of 220 l / in is shown. Using screen printing equipment, the prepared liquid metallic ink is printed onto the luminescent active layer 3 prepared in step three at a screen spacing of 4 mm, a printing pressure of 0.4 MPa, a squeegee angle of 70°, and a printing speed of 10 cm / s. After drying at room temperature, the pattern electrode layer of the stretchable smart anti-counterfeiting photoadhesive is obtained, ultimately forming the stretchable smart anti-counterfeiting photoadhesive, with the structure as shown. Figure 1 As shown.

[0069] The content of this invention is not limited to the embodiments listed. Any equivalent modifications made by those skilled in the art to the technical solutions of this invention by reading this specification are covered by the claims of this invention.

Claims

1. A stretchable intelligent anti-counterfeiting optical sticker, characterized in that, It includes a base layer (1), a bottom electrode layer (2), a light-emitting active layer (3), and a patterned electrode layer (4) stacked sequentially from bottom to top. The substrate layer (1) is a stretchable flexible polydimethylsiloxane film; The raw materials for the bottom electrode layer (2) include an aqueous solution of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, pentanediol, N,N-dimethylacetamide, and polyethylene glycol octylphenyl ether in a volume ratio of (85~95):(2~7):(2~7):1; wherein the mass fraction of the aqueous solution of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid is 1.3%; The raw materials of the light-emitting active layer (3) include a mixed solution obtained by mixing a 5 mg / ml tetrahydrofuran solution of the conjugated polymer Super yellow, a 10 mg / ml cyclohexanone solution of lithium bis(trifluoromethanesulfonylimide) and a 10 mg / ml cyclohexanone solution of polyethylene oxide, and polyethylene glycol octylphenyl ether in a mass ratio of 1:1 with the mixed solution. The raw material of the patterned electrode layer (4) is gallium indium eutectic alloy liquid metal ink. The raw material of the gallium indium eutectic alloy liquid metal ink includes gallium indium eutectic alloy liquid metal and PEO solution in a mass ratio of 3:

1. The PEO solution is a mixed solution of polyethylene oxide, disodium lauryl sulfonate monosuccinate and deionized water in a mass ratio of (35~45):1:1000. The stretchable smart anti-counterfeiting photosensitive sticker is attached to the product packaging. After connecting the positive and negative terminals of the external power supply to the bottom electrode layer (2) and the pattern electrode layer (4) respectively, pressing or stretching causes the non-conductive gallium oxide shell of the pattern electrode layer (4) to break, releasing the conductive liquid gallium indium alloy core to form a conductive path, which forms an electroluminescent effect with the light-emitting active layer (3) to display the preset pattern; the light emission stops when the power is disconnected, and the light emission occurs directly when the power is connected again.

2. The stretchable smart anti-counterfeiting optical sticker as described in claim 1, characterized in that, The gallium-indium eutectic alloy liquid metal has a gallium mass fraction of 75.5% and an indium mass fraction of 24.5%.

3. A method for preparing a stretchable smart anti-counterfeiting optical sticker as described in claim 1 or 2, characterized in that, Includes the following steps: Step 1: Cut the polydimethylsiloxane film into sheets with an area of ​​20 mm × 20 mm and a thickness of 3 mm to obtain the base layer (1) of the stretchable smart anti-counterfeiting photoadhesive. Step 2: Mix poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid aqueous solution, pentanediol, N,N-dimethylacetamide and polyethylene glycol octylphenyl ether in a volume ratio of (85~95):(2~7):(2~7):1 and stir thoroughly to prepare a mixed solution. Spin coat the solution onto the substrate layer (1) in Step 1. After spin coating, perform annealing treatment and then acid treatment on the upper surface of the film to obtain the bottom electrode layer (2) of the stretchable smart anti-counterfeiting photofilm. Step 3: Take a mixed solution with a volume ratio of (85~90):2:(8~13) of 5 mg / ml of the conjugated polymer Super yellow tetrahydrofuran solution, 10 mg / ml of the lithium bis(trifluoromethanesulfonylimide)cyclohexanone solution and 10 mg / ml of the polyethylene oxide cyclohexanone solution. Take the mixed solution and polyethylene glycol octylphenyl ether at a mass ratio of 1:1 and mix them thoroughly to prepare a luminescent blend. Spin coat the luminescent blend onto the bottom electrode layer (2) in step 2. After spin coating, perform annealing treatment to obtain the luminescent active layer (3) of the stretchable smart anti-counterfeiting photosheet. Step 4: Mix the pretreated gallium indium eutectic alloy liquid metal with PEO solution at a mass ratio of 3:1 and stir until uniform to obtain liquid metal ink; print the liquid metal ink onto the luminescent active layer (3) prepared in step 3 by screen printing, and dry at room temperature to obtain the pattern electrode layer (4) of the stretchable smart anti-counterfeiting photosheet.

4. The method for preparing the stretchable smart anti-counterfeiting optical sticker as described in claim 3, characterized in that, The acid treatment described in step two involves dripping benzoic acid to completely wet the surface of the film, acting it at room temperature for 15 minutes, then removing the excess benzoic acid from the surface, and allowing it to dry naturally at room temperature. The acid treatment was repeated three times.

5. The method for preparing the stretchable smart anti-counterfeiting optical sticker as described in claim 3, characterized in that, The spin coating described in steps two and three is performed at a rotation speed of 1000~1300 rpm and a spin coating time of 30~40 s; The annealing conditions are 100~120 ℃, annealing for 10~20 min.

6. The method for preparing the stretchable smart anti-counterfeiting optical sticker as described in claim 3, characterized in that, The thorough stirring mentioned in steps two and three refers to magnetic stirring for 6-12 hours; The stirring described in step four is magnetic stirring for 1-2 hours.

7. The method for preparing the stretchable smart anti-counterfeiting optical sticker as described in claim 3, characterized in that, The method for pretreatment of the gallium-indium eutectic alloy liquid metal in step four is to perform ultrasonic treatment with isopropanol followed by centrifugation; the ultrasonic treatment power is 300 W, the time is 1~2 min; the centrifugation speed is 1500 rpm, and the time is 2~3 min.

8. The method for preparing the stretchable smart anti-counterfeiting optical sticker as described in claim 3, characterized in that, The screen printing described in step four uses a printing plate with a mesh count of 200~250 l / in, a screen spacing of 3~5 mm, a squeegee angle of 70°, a printing pressure of 0.3~0.45 MPa, and a printing speed of 10 cm / s.

Images