Nanoimprint method for preparing flexible micro-nano structure on basis of PET (Polyethylene Terephthalate)
The preparation of flexible micro-nano structures on PET substrates through solution-assisted thermal nanoimprinting technology solves the limitations of traditional rigid substrate metal photonic crystals in flexible applications, and realizes the efficient and accurate preparation of metal photonic crystals on flexible substrates effect.
Patent Information
- Application Number
- CN202411786489.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-05
- Publication Date
- 2025-02-14
AI Technical Summary
Traditional rigid substrate metal photonic crystals have limitations in applications where flexibility and deformability are required, and it is difficult for the prior art to efficiently and accurately prepare metal photonic crystals on flexible substrates.
Using solution-assisted thermal nanoimprinting technology, flexible micro-nano structures were prepared on polyethylene terephthalate (PET) substrates, and a variety of periodic metal photonic crystal patterns were imprinted on the PET surface through PDMS molds. , and the structure of metal photonic crystal is formed by annealing.
It realizes efficient and precise preparation of metal photonic crystals on flexible substrates, maintains their optical properties and mechanical stability, and is suitable for wearable devices and flexible displays.
Smart Images
Figure HDA0005174189600000011 
Figure HDA0005174189600000012 
Figure HDA0005174189600000013
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of flexible metal photonic crystals, and in particular to a method for preparing flexible metal photonic crystals based on thermal nanoimprinting. Background Art
[0002] In the field of nanophotonics, metal photonic crystals have attracted extensive attention due to their unique optical properties and potential application prospects. Metal photonic crystals can manipulate the propagation of light and realize the localization, modulation and transmission of light, which makes them show great application potential in optoelectronics, sensors, optical devices and other fields. However, traditional rigid substrate metal photonic crystals have certain limitations in practical applications, especially in situations that require flexibility and deformability.
[0003] In order to expand the application range of metal photonic crystals, researchers have begun to focus on the preparation technology of metal photonic crystals on flexible substrates. The introduction of flexible substrates can not only maintain the optical properties of metal photonic crystals, but also provide additional mechanical flexibility, allowing metal photonic crystals to maintain stable performance in different working environments.
[0004] As an efficient nano-manufacturing technology, nano-imprinting technology is favored because it can achieve large-area, low-cost, and high-resolution nano-structure replication. Through nano-imprinting technology, the nano-structure on the pre-prepared mold can be accurately transferred to a flexible substrate to prepare flexible metal photonic crystals. The successful application of this technology is expected to realize the mass production of flexible metal photonic crystals and promote their application in wearable devices, flexible displays, biomedical sensors and other fields.
[0005] The present invention aims to solve the challenges in the prior art and provides a method for preparing metal photonic crystals on a flexible substrate based on nanoimprint technology. The method achieves efficient and accurate preparation of metal photonic crystals on a flexible substrate by optimizing the imprinting process and material selection, while ensuring its optical performance and mechanical stability. The technical solution of the present invention is expected to promote the application of flexible metal photonic crystals in multiple fields and provide new impetus for the development of nanophotonics. Summary of the invention
[0006] The present invention aims to propose a nanoimprint technology for manufacturing flexible micro-nano structures on a polyethylene terephthalate (PET) substrate. The technology uses a solution-assisted hot embossing process to emboss a variety of periodic metal photonic crystal patterns on the PET surface through a PDMS mold. The method is simple to operate and can produce flexible metal photonic crystals that are suitable for skin adhesion.
[0007] To achieve the above objectives, the present invention provides a nanoimprinting technology of the following steps for preparing a flexible micro-nano structure on a PET substrate:
[0008] (1) Preparing a gold nanocolloid solution: using oil-soluble gold nanoparticles prepared by the Burst method as a raw material, mixing the gold nanoparticles with an organic solvent of xylene, and subjecting the mixture to ultrasonic treatment and magnetic stirring to form a gold nanocolloid solution with a concentration of 50-100 mg / ml;
[0009] (2) Hot embossing: Place a 0.2 mm thick PET film on a heating device at 100 degrees Celsius for 5 to 10 seconds until the surface temperature of the PET film reaches 100 degrees Celsius. Then, extract the gold nanocolloid solution prepared in step (1) and drip it onto the PET substrate. 2 8-12 microliters of gold nanocolloid solution is applied to the PET film of the substrate; then, a PDMS template with a nanoscale concave or convex periodic pattern on the surface is immediately pressed onto the substrate, with the pattern side facing down and attached to the PET film, and 0.25-1kg / cm 2 The pressure was maintained for 30 to 60 seconds to ensure that the gold nanocolloid solution completely penetrated the gap between the PET film and the PDMS template pattern;
[0010] (3) Separating the mold from the substrate: Carefully remove the PET substrate and the PDMS template from the heating device in step (2); then, let them stand at room temperature for 1 to 3 minutes to cool down naturally. During this process, a structure matching the nano-periodic pattern on the PDMS mold will be formed on the PET substrate, and then the PDMS mold is peeled off from the PET substrate;
[0011] (4) Annealing: The PET substrate with the nanoscale periodic pattern obtained in step (3) is placed in a high-temperature furnace preheated to 180 degrees Celsius to 220 degrees Celsius for annealing for 20 to 30 minutes. This process is intended to melt the gold nanoparticles and form a metal photonic crystal structure. (5) Annealing and cooling: After the annealing process is completed, the PET substrate is placed in a room temperature environment and allowed to cool naturally for 3 to 5 minutes. Through this step, a large-area metal photonic crystal structure can be constructed on the flexible substrate.
[0012] The method also includes the following step (6): the PET substrate having the metal photonic crystal structure obtained in step (5) is used to repeat steps (2) to (5), wherein the corresponding PDMS templates are the same or different, or the placement direction or position of the PDMS template is adjusted as needed.
[0013] The present invention has the following advantages:
[0014] (1) The present invention does not require expensive photolithography masks, thus significantly reducing production costs.
[0015] (2) The present invention can be used to replicate patterns on large-area flexible substrates, which is particularly important for the production of large-area flexible electronic devices.
[0016] (3) The present invention manufactures a structure on a flexible substrate, and the resulting product has good flexibility and deformability, and is suitable for use in wearable devices, etc.;
[0017] (4) The present invention is relatively simple to operate and is easy to automate and mass produce, thereby improving production efficiency.
[0018] (5) The present invention can easily change the design of the mold to quickly produce products with different patterns and structures, which makes the technology highly adaptable. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is a SEM image of nanowires with a period of 500 nm prepared in Example 1 of a nanoimprinting method for preparing flexible micro-nano structures on PET according to the present invention;
[0020] Figure 2 This is a SEM image of a nanowire grating with a period of 500 nm prepared in Example 2 of a nanoimprint method for preparing a flexible micro-nano structure on PET according to the present invention;
[0021] Figure 3 This is a SEM image of a nanowire grating with a period of 500 nm prepared in Example 3 of a nanoimprint method for preparing a flexible micro-nano structure on PET according to the present invention;
[0022] Figure 4 This is a SEM image of a nanowire grating with a period of 500 nm prepared in Example 4 of a nanoimprint method for preparing a flexible micro-nano structure on PET according to the present invention;
[0023] Figure 5 This is a SEM image of two-dimensional nanowires prepared in Example 5 of a method for preparing flexible micro-nano structures on PET based on nanoimprinting of the present invention;
[0024] Figure 6 This is a SEM image of two-dimensional nanowires prepared in Example 6 of a method for preparing flexible micro-nano structures on PET based on nanoimprinting of the present invention;
[0025] Figure 7 This is a SEM image of two-dimensional nanowires prepared in Example 7 of a method for preparing flexible micro-nano structures on PET based on nanoimprinting of the present invention;
[0026] Figure 8 This is a diagram of the bending process of Embodiment 8 of a method for preparing a flexible micro-nano structure on PET based on nanoimprinting of the present invention;
[0027] Fig. 9 This is a SEM image of nanowires with a period of 500 nm prepared in Example 8 of a nanoimprinting method for preparing flexible micro-nano structures on PET according to the present invention. DETAILED DESCRIPTION
[0028] The present invention is further described below in conjunction with examples, but the present invention is not limited to these examples.
[0029] Example 1
[0030] (1) PET plastic was selected as the substrate material for the nanoimprinting process. The PET substrate was first ultrasonically cleaned in a mixed solution of acetone and alcohol for 15 minutes, and then dried with nitrogen. Hexanethiol-coated gold nanoparticles were selected, and xylene was selected as the solvent to prepare a gold solution with a concentration of 100 mg / ml. To prevent the nanoparticles from agglomerating, the solution was ultrasonically cleaned for 15 minutes.
[0031] (2) The oil-phase gold nanoparticles synthesized by the Burst technique were mixed evenly with xylene to form a gold nanoparticle solution with a concentration of 50 mg / ml. After ultrasonic treatment for 15 minutes, micron-sized magnetic beads were added and placed in a magnetic stirrer and stirred at a set speed of 1300 rpm and a temperature of 40°C for 30 minutes to promote uniform dispersion of the gold nanoparticles.
[0032] (3) Place the PET substrate (area 20 mm*20 mm, 0.2 mm) on a hot platform preheated to 100°C, ensure that the PET substrate is aligned with the edge of the platform, and perform rapid heating for 5 seconds. Next, drop 8 μL of 50 mg / mL gold nanoparticle solution and cover it with a 500 nm period PDMS mold. Apply a pressure of 0.125 kg / cm2 and maintain for 1 minute to allow the solution to fully infiltrate between the PET substrate and the PDMS mold.
[0033] (4) Carefully remove the PET substrate and PDMS mold assembly from the heating device, and then place it at room temperature for 1 to 3 minutes to cool naturally, so that a structure consistent with the nanopattern of the PDMS mold is formed on the PET substrate, and finally remove the PDMS mold.
[0034] (5) The PET substrate with the imprinted grating structure is placed in a high-temperature furnace preheated to 200° C. for annealing for 20 minutes to melt the metal nanoparticles and form a nanostructure of the metal photonic crystal. After the annealing is completed, the substrate is taken out and cooled at room temperature for 5 minutes.
[0035] The final SEM image is as follows Figure 1 The metallic photonic crystal structure shown in Figure 1. The uniform nanowire structure can be seen.
[0036] Example 2
[0037] A method for manufacturing a flexible micro-nano structure on a PET substrate using nanoimprint technology, the operation process of which is consistent with Example 1. However, there is a key difference: in the third step, the imprint pressure originally used, which was 0.125 kg / cm2, is now replaced by a pressure of 0.25 kg / cm2.
[0038] With this modification, the resulting scanning electron microscope (SEM) images show Figure 2 The metallic photonic crystal structure shown, where uniformly distributed nanowire arrays can be observed.
[0039] By Example 1 Figure 1 and Example 2 Figure 2 In comparison, the grating line width was widened after increasing the imprint pressure, from 135nm to 175nm.
[0040] Example 3
[0041] A method for manufacturing a flexible micro-nano structure on a PET substrate using nanoimprint technology, the operation process of which is consistent with Example 1. However, there is a key difference: in the third step, the imprint pressure originally used, which was 0.25 kg / cm2, is now replaced by a pressure of 1 kg / cm2.
[0042] With this modification, the resulting scanning electron microscope (SEM) images show Figure 3 The metallic photonic crystal structure shown, where uniformly distributed nanowire arrays can be observed.
[0043] By Example 2 Figure 2 and Example 3 Figure 3 In comparison, the grating line width was widened after increasing the imprint pressure, from 175nm to 200nm.
[0044] Example 4
[0045] A method for fabricating a flexible micro-nanostructure on a PET substrate using nanoimprint technology, the operation process of which is consistent with Example 2. However, there is a key difference: in the third step, the gold nanoparticle solution originally used, whose concentration is 100 mg / ml, is now replaced by a solution with a concentration of 50 mg / ml.
[0046] With this modification, the resulting scanning electron microscope (SEM) images show Figure 4 The metallic photonic crystal structure shown, where uniformly distributed nanowire arrays can be observed.
[0047] By Example 2 Figure 2 and Example 4 Figure 4 In comparison, after reducing the concentration, the resulting grating structure has fewer gold nanoparticles in the grooves, and the alignment between the gold lines and grooves is higher.
[0048] Example 5
[0049] A process for manufacturing a flexible micro-nano structure on a polyethylene terephthalate (PET) substrate by nanoimprinting technology, wherein steps 1 to 5 are the same as those in Example 4. The innovation of this method is that step 6 is introduced between step 4 and step 5. Through these additional steps, the obtained scanning electron microscope (SEM) image shows Figure 5 The photonic crystal structure shown in the figure has obvious two-dimensional structural features, clear structural details, and evenly distributed grid lines.
[0050] In step 6, the PET substrate with the grating pattern is placed on a heating platform preheated to 100°C, ensuring that the edge of the substrate is aligned with the edge of the platform. After heating for 5 seconds, 8 microliters of the gold nano solution (as described in step 2) is dropped on the PET substrate with the grating pattern. Subsequently, a 500-nanometer-thick polydimethylsiloxane (PDMS) mold is imprinted on the PET substrate, and a pressure of 0.25 kg / cm2 is applied for 1 minute to ensure that the solution fully penetrates between the PET substrate and the PDMS mold. Then, the annealing process of step 5 is performed to obtain a two-dimensional micro-nano structure.
[0051] The final SEM image is as follows Figure 5 As shown, the photonic crystal structure is revealed, in which two 500nm grating structures are clearly visible and the grating lines are uniform and consistent.
[0052] Example 6
[0053] A method for preparing a flexible micro-nano structure on PET based on nanoimprinting, the steps are the same as those in Example 5, except that the concentration of the gold nanocolloid solution prepared in step (2) is 100 mg / ml. The SEM image is as follows Figure 6 In the two-dimensional metal photonic crystal structure shown in the figure, uniform gold nanowires can be seen, and there are also a small number of dispersed gold nanoparticles in the grooves formed by the gate lines.
[0054] Example 7
[0055] A method for preparing a flexible micro-nano structure on PET based on nanoimprinting, the steps are the same as those in Example 4, except that: in step (7), the PET is placed at an angle of 45° to the edge of the heating table, and the SEM image is finally obtained as shown in FIG. Figure 5 The two-dimensional metallic photonic crystal structure shown in.
[0056] Example 8
[0057] A method for manufacturing a flexible micro-nano structure on a PET substrate using nanoimprint technology, the operation process of which is consistent with Example 2. The difference is that the sample to be tested is repeatedly bent along multiple predetermined directions for 200 times each. The process is as follows Figure 8 As shown; then, the surface of the sample was observed using a scanning electron microscope (SEM). The experimental results show that after the bending process, the microstructure of the sample surface is as shown in the SEM. Fig. 9 As shown, the morphology does not change significantly compared to before bending, which proves the excellent bending resistance of the material.
Claims
1. A method for preparing flexible micro-nano structures on PET based on nanoimprinting, characterized in that: The following steps are involved: (1) Preparing a gold nanocolloid solution: using oil-soluble gold nanoparticles prepared by the Burst method as a raw material, mixing the gold nanoparticles with an organic solvent of xylene, and subjecting the mixture to ultrasonic treatment and magnetic stirring to form a gold nanocolloid solution with a concentration of 50-100 mg / ml; (2) Hot embossing: Place a 0.2 mm thick PET film on a heating device at 100 degrees Celsius for 5 to 10 seconds until the surface temperature of the PET film reaches 100 degrees Celsius. Then, extract the gold nanocolloid solution prepared in step (1) and drip it onto the PET substrate. 2 8-12 microliters of gold nanocolloid solution is applied to the PET film of the substrate; then, a PDMS template with a nanoscale concave or convex periodic pattern on the surface is immediately pressed onto the substrate, with the pattern side facing down and attached to the PET film, and 0.25-1kg / cm 2 The pressure was maintained for 30 to 60 seconds to ensure that the gold nanocolloid solution completely penetrated the gap between the PET film and the PDMS template pattern; (3) Separating the mold from the substrate: Carefully remove the PET substrate and the PDMS template from the heating device in step (2); then, let them stand at room temperature for 1 to 3 minutes to cool down naturally. During this process, a structure matching the nano-periodic pattern on the PDMS mold will be formed on the PET substrate, and then the PDMS mold is peeled off from the PET substrate; (4) Annealing treatment: placing the PET substrate with the nanoscale periodic pattern obtained in step (3) into a high temperature furnace preheated to 180 degrees Celsius to 220 degrees Celsius for annealing treatment for 20 to 30 minutes; this process is intended to melt the gold nanoparticles and thereby form a metal photonic crystal structure; (5) Annealing and cooling: After the annealing process is completed, the PET substrate is placed in a room temperature environment and allowed to cool naturally for 3 to 5 minutes. Through this step, a large-area metal photonic crystal structure can be finally constructed on the flexible substrate.
2. The method according to claim 1, characterized in that The method also includes the following step (6): the PET substrate having the metal photonic crystal structure obtained in step (5) is used to repeat steps (2) to (5), wherein the corresponding PDMS templates are the same or different, or the placement direction or position of the PDMS template is adjusted as needed.
3. The flexible micro-nano structure prepared according to the method of claim 1 or 2.