A method for preparing three-dimensional micro-nano structure along dislocation line of liquid crystal polymer surface

Abstract

The application discloses a method for preparing three-dimensional micro-nano structure along disclination line of liquid crystal polymer surface, which comprises the following steps: S1, setting a filling area of a liquid crystal cell; S2, performing light-controlled orientation on the liquid crystal cell; S3, filling a liquid crystal mixture into the filling area, and performing photopolymerization on the liquid crystal mixture to form a thin film of liquid crystal polymer; disassembling the liquid crystal cell, and increasing the height of the filling area; S4, heating the thin film of liquid crystal polymer, and then placing the thin film in an electric field to form a three-dimensional micro-nano structure. The application aims at overcoming the shortcomings of the existing preparation method of micro-nano structure, and proposes a method for preparing regular surface three-dimensional micro-nano structure from bottom to top. In particular, the application can control the structure according to the design of a substrate orientation layer, so that regular or complex surface topography can be prepared.

Description

Technical Field

[0001] This invention relates to the field of micro / nano surface structure fabrication, and in particular to a method for fabricating three-dimensional micro / nano structures along anatropy lines on the surface of a liquid crystal polymer. Background Technology

[0002] In the fabrication of micro / nano structures, methods can be broadly categorized into two main types: "top-down" and "bottom-up." Traditional "top-down" methods largely rely on photolithography, allowing nano / micro-scale structures to be fabricated in one (or multiple) photolithography steps. However, these methods typically require expensive optical equipment and complex processes, making the fabrication of micro / nano structures extremely difficult. Nanoimprinting is another method, transferring patterns from a stamp onto a polymer film via direct imprinting to create the corresponding structure. However, this imprinting method often introduces defects on the structure's surface. "Bottom-up" self-assembly technology offers a more promising approach for fabricating micro / nano structures. The self-assembly process forms three-dimensional micro / nano structures without direct pattern transfer, eliminating many cumbersome fabrication steps. During self-assembly, basic structural units (molecules, nanomaterials, micrometer-sized or larger substances) spontaneously aggregate into a stable structure with a relatively regular geometric appearance based on non-covalent interactions.

[0003] Liquid crystals are excellent self-assembling materials, possessing unique anisotropy and capable of self-assembling into microstructures in response to external stimuli. However, most current methods for preparing surface morphologies based on liquid crystals rely on the principle of disrupting the arrangement of liquid crystal molecules to generate free volume. This principle can prepare certain three-dimensional surface morphologies on the surface of liquid crystal polymer films, but this method struggles to form regular patterned three-dimensional structures, and the resulting structures have very low aspect ratios.

[0004] In summary, there is an urgent need to develop a new technical solution, namely, a micro / nano structure fabrication technology based on liquid crystal polymers, to facilitate the efficient fabrication of regular three-dimensional structures and solve the problems existing in current fabrication technologies. Summary of the Invention

[0005] This invention aims to overcome the shortcomings of existing methods for fabricating micro / nano structures by proposing a bottom-up method for preparing regular three-dimensional micro / nano structures. This invention utilizes a liquid crystal polymer film as a substrate to prepare the surface three-dimensional structure. The micro / nano structure is prepared by inducing the flow of liquid crystal polymer molecules through an electric field. Furthermore, due to the anisotropic flow of liquid crystals, the flow of liquid crystal molecules can be controlled using a director to generate the designed three-dimensional structure. In particular, this invention allows for control of the structure based on the design of the substrate alignment layer, thereby producing regular or complex surface morphologies.

[0006] Unlike the method for preparing micro / nano structures on the surface of liquid crystal polymers disclosed in the prior art CN113262735A, the method proposed in this patent can produce more regular three-dimensional structures. By forming staggered line patterns on the liquid crystal polymer film, the controllability of the liquid crystal polymer molecule flow can be further improved, resulting in the designed three-dimensional structure, such as concentric rings and periodically adjustable grating structures.

[0007] This invention discloses a method for fabricating three-dimensional micro / nano structures along misaligned lines on the surface of a liquid crystal polymer, comprising the following steps:

[0008] S1. Set the filling area of ​​the LCD cell;

[0009] S2. Perform light-controlled orientation on the liquid crystal cell;

[0010] S3. Fill the filling area with the liquid crystal mixture and perform photopolymerization on the liquid crystal mixture to form a thin film of liquid crystal polymer; disassemble the liquid crystal cell to increase the height of the filling area;

[0011] In this process, the filling region initially uses smaller spacers to limit its size to a smaller range. After the liquid crystal polymer is deposited, the spacers are replaced with larger ones, which allows the filling region to grow further and is beneficial for the natural growth of the liquid crystal polymer.

[0012] S4. The liquid crystal polymer film is heated and then placed in an electric field to form a three-dimensional micro / nano structure;

[0013] The liquid crystal mixture, after photopolymerization, has a smectic phase;

[0014] The filling region, under the action of the first and second alignment layers of the liquid crystal cell, causes the liquid crystal polymer to contain a number of misaligned lines and form a misaligned line pattern, which is consistent with the target structure pattern.

[0015] Liquid crystals are materials with anisotropic flow properties, meaning they flow with varying degrees of ease in each direction. This invention utilizes this property of liquid crystals to prepare regular micro / nano structures by controlling their flow. Notably, the liquid crystal material used in this invention is a smectic liquid crystal material, exhibiting even more pronounced anisotropy during flow. The selected liquid crystal mixture material should meet the following conditions: (1) it is a monomer material containing an acrylate structure suitable for photopolymerization; (2) the liquid crystal mixture has a liquid crystal phase, and the polymer after photopolymerization has a smectic phase.

[0016] The materials selected in this invention offer the following mechanistic benefits: smectic liquid crystals have a layered structure formed by the aggregation of rod-shaped liquid crystal molecules. Within each layer, the long axes of the liquid crystal molecules are parallel and arranged neatly, their orientation either perpendicular or inclined to the layer plane. This layered structure results in significant anisotropy in the flow of smectic liquid crystal molecules; while the molecules can flow within the layered structure, flow between layers becomes extremely difficult. This invention utilizes this characteristic to design a self-assembly method for well-organized micro / nano structures.

[0017] In some embodiments of the present invention, to further obtain a defect-free, continuous, and neat protrusion structure, the growth method of the protrusions is optimized: firstly, a liquid crystal cell with a small gradient thickness is used, thereby enabling the protrusions to grow in an extended manner. This extended growth method reduces defects generated during the growth process, resulting in a more continuous and complete structure. Specifically, the electric field force provided at different cell thickness locations varies; a larger electric field force is obtained in relatively thinner areas of the liquid crystal cell, causing the protrusions to grow preferentially, thus guiding the growth of protrusions in other areas.

[0018] Further, in step S4, the heating temperature T satisfies: the clearing point temperature T of the liquid crystal polymer. i ≥T≥ glass transition temperature T of liquid crystal polymer g .

[0019] In order to achieve both flowability and room-temperature structural stability, the material system used in this invention employs a smectic liquid crystal polymer as a substrate. Unlike small-molecule liquid crystals, polymeric liquid crystals, when heated to T... g Above a certain temperature, polymer molecular chains begin to move, creating a flow effect. When the temperature drops to T... g The polymer molecular chain segments are then frozen, fixing the current morphology.

[0020] This invention utilizes an electric field effect principle called EHDI to fabricate micro / nano structures. When the liquid crystal polymer film is in a T... g When the liquid crystal molecules are above the surface, they possess the ability to flow. At this point, an electric field is applied to the liquid crystal molecules, and the initially flat film surface, maintained by surface tension, begins to experience thermal disturbance. When the electric field force exceeds the surface tension, the liquid crystal molecules break through the flat film surface and begin to grow upwards. The heating temperature T is greater than or equal to the glass transition temperature Tglass of the liquid crystal polymer. g The electric field is the threshold voltage that drives the liquid crystal polymer to undergo EHDI.

[0021] It is worth noting that the alignment effect of the liquid crystal material on the substrate affects the growth mode of the liquid crystal molecules. The smectic liquid crystal polymer used in this invention grows raised stripes along the direction of the molecular orientation vector. However, in uniaxially oriented liquid crystal polymer films, growth cannot be strictly parallel to the molecular orientation vector direction, due to defects in the alignment process. Furthermore, the simultaneous growth of protrusions within the same plane without substrate intervention also results in chaotic growth. To address these two issues and prepare irregular protrusion structures, this invention proposes two methods, as follows:

[0022] By designing the substrate director distribution, the growth sequence of protrusions in different regions is influenced. This invention employs a special optical alignment layer pattern, such as... Figure 2 As shown, liquid crystal monomers are arranged according to the designed photo-alignment layer pattern, and after photopolymerization and fixation, polymer films with the same arrangement are obtained. This alternating alignment method forms a misalignment line at the boundary between two different alignment regions, which introduces a strong boundary effect, and the growth of liquid crystal protrusions preferentially occurs at these locations. We optimized this process. When the period of the misalignment line is equal to the characteristic distance of the protrusion under this condition, a misalignment line with an included angle of 45° can produce regular protrusions. This is because the structures grown using the EHDI principle have a fixed spacing, which we call the characteristic distance. When the designed misalignment line period is equal to this characteristic distance, the protrusion can grow along the misalignment line; when the designed misalignment line is greater than 2 times or less than 0.5 times the characteristic distance, the protrusion will not be able to grow along the misalignment line and will grow generally in the direction of the director. It is worth noting that not all misalignment lines formed by the director angle can produce the above results. Experiments have verified that misalignment lines formed by the liquid crystal director at a 45° angle can effectively enable the protrusion to grow along the misalignment line.

[0023] Furthermore, in step S4, the electric field is a DC electric field with an electric field strength E ≥ 10. 7 V·m -1 .

[0024] Furthermore, in the directional line pattern, the angle between the two adjacent regions forming the directional line is in the range of 30°-60°.

[0025] Further, in step S3, the liquid crystal mixture includes a liquid crystal monomer and a photoinitiator, wherein the liquid crystal monomer is selected from acrylate liquid crystal materials.

[0026] Furthermore, the liquid crystal cell includes a first substrate and a second substrate, with a filling region disposed between the first substrate and the second substrate. The first substrate includes a first alignment layer disposed on one side facing the filling region and a first conductive substrate adjacent to the first alignment layer. The second substrate includes a second alignment layer disposed on one side facing the filling region and a second conductive substrate adjacent to the second alignment layer.

[0027] Furthermore, the thickness of the filled region is 0.2-50 μm, thereby obtaining a liquid crystal polymer film with a film thickness of 0.2-50 μm.

[0028] Furthermore, the target structural pattern is fabricated using a DMD digital mask lithography system.

[0029] In some embodiments of this invention, a DMD digital mask lithography system is used to perform photo-controlled alignment of liquid crystal molecules. Traditional PVA triboelectric alignment methods have not yielded satisfactory results in this invention because these methods rely on grooves created by friction to anchor the liquid crystal molecules, introducing a large number of dust particles and other impurities that hinder the flow of the liquid crystal molecules. DMD alignment technology, however, does not affect this invention: it first uses linearly polarized light (wavelength 365nm) to align photosensitive azobenzene molecules (such as SDI), and then the liquid crystal molecules align along the azobenzene molecules, achieving the alignment effect. When a smectic liquid crystal polymer film with a direction deparallel to the glass substrate is prepared, under suitable temperature and electric field (the heating temperature T ≥ the glass transition temperature Tg of the liquid crystal polymer; the electric field is the threshold voltage for driving the liquid crystal polymer to undergo EHDI), it can flow perpendicular to the ITO conductive substrate to grow micro / nano structures. It is worth noting that by using DMD, we can set some special gradients and binary patterns to obtain liquid crystal molecules with non-uniaxial orientation and special orientation, which is an effect that traditional orientation technology cannot achieve.

[0030] DMD designs different digital mask patterns, and by changing the width of the digital mask pattern, it can grow regular stripes of varying thickness and spacing. This control process does not require the complex transformations of traditional photolithography micro / nano fabrication methods; it only requires adjusting the DMD program to design substrates with different orientations.

[0031] Furthermore, the liquid crystal mixture comprises 0.5 to 2.0 parts by weight of a photoinitiator and 98.0 to 99.5 parts by weight of liquid crystal monomers.

[0032] In some embodiments of the present invention, the liquid crystal mixture described in S3, comprising photocurable liquid crystal monomers and a photoinitiator, is filled into the filled region. The liquid crystal monomers are oriented according to a photo-alignment layer pattern design, and then, under illumination (light intensity of 25 mW / cm²; light wavelength of 365 nm), the liquid crystal monomers undergo photopolymerization under the action of the photoinitiator to form an oriented liquid crystal polymer. It is noteworthy that the polymerization process does not affect the original orientation of the liquid crystal molecules, thus yielding a film with the same orientation as the liquid crystal molecules.

[0033] Furthermore, the photoinitiator is a free radical photoinitiator.

[0034] The present invention has the following beneficial effects:

[0035] 1. This invention mainly utilizes the electrohydrodynamic instability (EHDI) in liquid crystal polymer films and combines it with the significant flow anisotropy of smectic liquid crystals to form regular micro-nano structures along misaligned lines by pre-designing patterned and oriented substrates.

[0036] 2. This invention proposes a method for fabricating regular micro / nano structures, which allows for adjustment of the parameters of the generated regular protrusions according to practical applications, and also enables the design of directories to fabricate morphologies of different shapes. This is a very practical bottom-up micro / nano structure fabrication method, thus providing a novel approach to the self-assembly of liquid crystal materials.

[0037] 3. The present invention will utilize this boundary effect to achieve the following applications: (1) to prepare regular parallel micro-nano structures, wherein the present invention can also control the regular structure grown, and change the period of the directional misalignment within a suitable range. This regular arrangement structure can be applied to the field of gratings, providing a convenient method for preparing the structure and application of liquid crystal gratings; (2) to prepare complex surface morphologies. Attached Figure Description

[0038] Figure 1 A schematic diagram of the liquid crystal cell in Embodiment 1 is shown.

[0039] Figure 2 (a) shows a schematic diagram of the alignment layer designed by the digital mask used in Example 1, where the short lines represent the position and direction of the liquid crystal molecules, the directional vectors of two adjacent regions form a 45° angle, and a straight directional line is formed at the boundary region; Figure 2 (b) is a polarized microscope image of the formed thin film.

[0040] Figure 3 A schematic diagram of the structure of the liquid crystal cell formed after increasing the filling area in Example 1 is shown.

[0041] Figure 4A polarized microscope image of the surface micro / nano structure formed by the liquid crystal polymer in Example 1 is shown.

[0042] Figure 5 (a) A grating structure with a period of 30 μm. Figure 5 (b) is a grating structure with a period of 20 μm. By adjusting the period of the eccentric lines, polarized microscope images of structures with different periods can be obtained.

[0043] Figure 6 (a) is a schematic diagram of the alignment layer designed by the digital mask used in Example 2, where the short lines represent the position and direction of the liquid crystal molecules, the angle between the directional vectors of two adjacent regions is 45°, and a circular directional line is formed at the junction; (b) is a polarized microscope image of the formed film.

[0044] Figure 7 (a) is a schematic diagram of the alignment layer designed by the digital mask used in Example 2, where the short lines represent the position and direction of the liquid crystal molecules, the angle between the directional arrows of two adjacent regions is 45°, and a square directional line is formed at the boundary region; (b) is a polarized microscope image of the formed film.

[0045] Figure 8 This is a polarized microscope image of the surface micro / nano structure formed by the liquid crystal polymer in Example 2.

[0046] Figure 9 This is a polarized microscope image of the surface micro / nano structure formed by the liquid crystal polymer in Example 2.

[0047] Attached image labels:

[0048] First substrate-100; Second substrate-200; First spacer-300; Filled area-400; First conductive substrate-110; First substrate-111; First conductive layer-112; First alignment layer-120; Second conductive substrate-210; Second substrate-211; First conductive layer-112; Second alignment layer-220; Second spacer-600. Detailed Implementation

[0049] To more clearly illustrate the technical solution of the present invention, the following embodiments are provided. Unless otherwise stated, the raw materials, reactions, and post-processing methods appearing in the embodiments are all commercially available raw materials and technical methods well known to those skilled in the art.

[0050] The terms "preferred," "more preferably," and "more suitable" used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0051] Example 1

[0052] A method for fabricating three-dimensional micro / nano structures along misalignment lines on the surface of a liquid crystal polymer, comprising the following steps:

[0053] L1. Preparation of liquid crystal material: 49 wt% of photocurable liquid crystal monomer SFD1535, 49 wt% of photocurable liquid crystal monomer SFD065 and 2.0 wt% of photoinitiator IGR819 are mixed, and the liquid crystal monomer and photoinitiator are dissolved in dichloromethane to form a liquid crystal mixture. The liquid crystal mixture is then obtained by evaporating the dichloromethane.

[0054] L2. Preparation of photoalignment layer on ITO glass substrate: First, prepare 0.3 wt% photoalignment material SD1, then take 10 μL and spin coat it onto ITO glass substrate. Spin coat at 800 rpm for 8 s, then at 3000 rpm for 30 s; a photoalignment layer with a thickness of 10 nm is formed on ITO glass substrate.

[0055] S1. Fabrication of a liquid crystal cell containing an alignment layer: Two ITO glass substrates with alignment layers spin-coated in step L2 are used to fabricate a liquid crystal cell. The liquid crystal cell includes a first substrate 100 and a second substrate 200. A filling region 400 is formed between the first substrate 100 and the second substrate 200 through a first spacer 300. The first substrate 100 includes a first conductive substrate 110 and a first alignment layer 120 disposed on the side facing the filling region 400. The second substrate 200 includes a second conductive substrate 210 and a second alignment layer 220 disposed on the side facing the filling region 400. In this embodiment, the first conductive substrate 110 and the second conductive substrate 210 are used to facilitate the application of voltage. In this embodiment, both the first alignment layer 120 and the second alignment layer 220 are alignment layers prepared in step L2. The height of the filling region 400 is controlled by the first spacer 300. In this embodiment, the first spacer 300 is spherical with a diameter of 3 μm, thereby controlling the height of the filling region 400 to be 3 μm. The first conductive substrate 110 includes a first substrate 111 and a first conductive layer 112. The second conductive substrate 210 includes a second substrate 211 and a second conductive layer 212. The first substrate 111 and the second substrate 211 are light-transmitting substrates to facilitate the transmission of light and induce the polymerization of the filled liquid crystal monomers. In this embodiment, the first conductive substrate 110 and the second conductive substrate 210 are ITO glass substrates.

[0056] Figure 1 A schematic diagram of the liquid crystal cell is shown.

[0057] S2. Perform light-controlled orientation of the liquid crystal cell: Design digital mask pattern. Figure 2 (a) For the director pattern we designed, the corresponding digital mask of the pattern is input into the DMD digital mask system to orient the alignment coating, forming a light alignment layer with a predetermined orientation corresponding to the target information; wherein, the liquid crystal director structure of the light alignment layer formed by the digital mask is as follows: Figure 2 As shown in (a) (alternating striped liquid crystal pointers arranged at a 45° angle), the structure of the digital mask corresponds to... Figure 2 The liquid crystal pointing structure shown in (a) is configured to achieve the following during the orientation process: Figure 2 (a) shows the writing of the target information, so that the formed filling area 400 has the same characteristics as... Figure 2 (a) shows the target information corresponding to the predetermined orientation. The effect of the filled area after orientation is as follows: Figure 2 As shown in (b).

[0058] S3. Fill the filling area 400 with liquid crystal mixture: Take the liquid crystal mixture from step L1 and fill the filling area 400 with the liquid crystal mixture at a temperature above its clearing point (130°C), and then slowly cool it down to the liquid crystal phase (110°C); use an LED lamp with a wavelength of 365 nm, adjust the light intensity to 25 mW / cm², irradiate it from the second substrate 200 toward the first substrate 100 and perform photopolymerization for 10 min. Due to the effect of the first alignment layer 120 and the second alignment layer 220, the thin film of the liquid crystal polymer formed after photopolymerization has the 45° angled alternating stripe orientation designed in S2, which is arranged parallel to the first substrate 100 and the second substrate 200.

[0059] The photopolymerized liquid crystal cell is opened. During photopolymerization, due to the difference in light intensity at the interface between the first substrate 100 and the second substrate 200, the degree of photopolymerization is higher near the second substrate 200. This results in the liquid crystal polymer 500 formed by photopolymerization remaining on the second substrate 200. A portion of the liquid crystal polymer film is scraped off with a blade, and then a new thin-film liquid crystal cell is prepared using a second spacer 600 with a larger diameter. Figure 3 As shown. In this embodiment, the height of the second spacer 600 is 6 μm, and a liquid crystal polymer / air interface is formed between the liquid crystal polymer 500 and the air in the filling region 400.

[0060] S4. The newly formed liquid crystal cell is placed on a hot stage at a temperature of 110°C (the glass transition temperature Tg of the liquid crystal polymer formed in this embodiment is 35°C). A power supply component is connected between the first conductive substrate 110 and the second conductive substrate 210. The power supply component is electrically connected to the first conductive layer (not shown in the figure) of the first conductive substrate 110 and the second conductive layer (not shown in the figure) of the second conductive substrate 210. The voltage of the power supply component is 150 V, resulting in an electric field strength E of 2.5 × 10⁻⁶. 7 V·m -1 Under the influence of an electric field and electrostatic force, the liquid crystal polymer fluid at the liquid crystal polymer / air interface overcomes surface tension and flows along the direction of the electric field lines. Due to the anisotropic flow of the liquid crystal polymer and the boundary effect caused by the misalignment lines, a regular striped micro-surface morphology is ultimately formed. The surface micro-nano morphology obtained after the power supply component is powered on for 20 minutes is shown in the figure. Figure 4 The image shown is a polarized microscope image of a liquid crystal polymer with parallel orientation induced by an electric field. It can be seen from the image that a regular striped surface micro / nano structure along the misalignment line was prepared using the method of this embodiment of the invention.

[0061] In step S3, we adjusted the width of the alternating orientation regions in the digital mask pattern to obtain an orientation layer containing misaligned lines with different periods. The resulting regular striped micro / nanostructure, grown after electrical heating, will have a period consistent with the misaligned lines, such as... Figure 5 As shown in (a)-(b).

[0062] Example 2

[0063] This embodiment provides a method for fabricating complex micro / nano structures on the surface of a liquid crystal polymer. The methods for fabricating concentric rings and concentric squares will be described here. The fabrication processes of the liquid crystal cell and the liquid crystal mixture are the same as in Example 1, the difference being the orientation layer of the formed liquid crystal polymer 500. To further obtain more complex surface morphologies, this invention designs a director pattern, utilizing the boundary effect of the misaligned lines to fabricate concentric rings, and concentric squares are fabricated using the same principle.

[0064] The liquid crystal pointing structure of the photoalignment layer formed by the digital mask is as follows: Figure 6 (a)-(b) and Figure 7 As shown in (a)-(b), Figure 6 (a)-(b) show the arrangement of liquid crystal pointing vectors in a near-circular shape. Figure 7 (a)-(b) are arranged in a square-like pattern of directional vectors.

[0065] Then, by performing the same steps as in Example 1, concentric circle and concentric square structures can be obtained, as shown below. Figure 8 , Figure 9 As shown.

[0066] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0067] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for fabricating three-dimensional micro / nano structures along misaligned lines on the surface of a liquid crystal polymer, characterized in that, The method for preparing three-dimensional micro / nano structures along the misalignment lines on the surface of the liquid crystal polymer includes the following steps: S1. Set the filling area of ​​the LCD cell; S2. Perform light-controlled orientation on the liquid crystal cell; S3. Fill the filling area with the liquid crystal mixture and perform photopolymerization on the liquid crystal mixture to form a thin film of liquid crystal polymer; disassemble the liquid crystal cell to increase the height of the filling area; S4. The thin film of the liquid crystal polymer is heated and then placed in an electric field to form a three-dimensional micro / nano structure; The liquid crystal mixture, after photopolymerization, has a smectic phase; The filling region, under the action of the first and second alignment layers of the liquid crystal cell, causes the liquid crystal polymer to contain a number of misalignment lines and form a misalignment line pattern, the misalignment line pattern being consistent with the target structure pattern; In the directional line pattern, the angle between the two adjacent regions forming the directional line is in the range of 30°-60°.

2. The method for preparing three-dimensional micro / nano structures along the cross-axis of the liquid crystal polymer surface according to claim 1, characterized in that, In step S4, the heating temperature T satisfies: the clearing point temperature T of the liquid crystal polymer. i ≥T≥ glass transition temperature T of liquid crystal polymer g .

3. The method for preparing three-dimensional micro / nano structures along the misaligned lines on the surface of a liquid crystal polymer according to claim 1, characterized in that, In step S4, the electric field is a DC electric field with an electric field strength E ≥ 10. 7 V·m -1 .

4. The method for preparing three-dimensional micro / nano structures along the misalignment lines on the surface of a liquid crystal polymer according to claim 1, characterized in that, In step S3, the liquid crystal mixture includes a liquid crystal monomer and a photoinitiator, wherein the liquid crystal monomer is selected from acrylate liquid crystal materials.

5. The method for preparing three-dimensional micro / nano structures along the misalignment lines on the surface of a liquid crystal polymer according to claim 1, characterized in that, The liquid crystal cell includes a first substrate and a second substrate, with a filling region disposed between the first substrate and the second substrate. The first substrate includes a first alignment layer disposed on one side facing the filling region, and a first conductive substrate adjacent to the first alignment layer. The second substrate includes a second alignment layer disposed on one side facing the filled region, and a second conductive substrate adjacent to the second alignment layer.

6. The method for fabricating three-dimensional micro / nano structures along the misalignment lines on the surface of a liquid crystal polymer according to claim 5, characterized in that, The thickness of the filling area is 0.2-50 μm.

7. The method for preparing three-dimensional micro / nano structures along the misalignment lines on the surface of a liquid crystal polymer according to claim 1, characterized in that, The target structural pattern was fabricated using a DMD digital mask lithography system.

8. The method for preparing three-dimensional micro / nano structures along the misalignment lines on the surface of a liquid crystal polymer according to claim 5, characterized in that, The liquid crystal mixture comprises 0.5 to 2.0 parts by weight of a photoinitiator and 98.0 to 99.5 parts by weight of liquid crystal monomers.

9. The method for preparing three-dimensional micro / nano structures along the misalignment lines on the surface of a liquid crystal polymer according to claim 4, characterized in that, The photoinitiator is a free radical photoinitiator.

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