CN117341370A - Preparation method of soft lithography seal attached to curved object without external force, product and application thereof - Google Patents

Abstract

The invention discloses a preparation method of a soft lithography seal attached to a curved object without external force, which comprises the following steps: (1) Synthesizing a cross-linked polymer material containing a photosensitive structure and a metal ion coordination structure at the same time, and swelling in a solvent; (2) The surface of the crosslinked polymer material is covered with an optical mask plate with a specific light transmission pattern, and the chemical structure of the region is changed under illumination, so that the microstructure appears on the surface of the crosslinked polymer material, and the soft lithography seal is obtained. The invention also discloses a soft lithography seal prepared by the method and application of the soft lithography seal in soft lithography, microstructural re-lithography of high polymer resin or regional etching of the surface of a curved object. The method directly uses ultraviolet light to trigger and does not need external force to obtain the soft lithography seal, and the obtained soft lithography seal can be reused and can be applied to curved surface micromachining.

Description

A preparation method and product of a soft photolithography seal that adheres to curved objects without external force products and applications

Technical field

The invention relates to the field of manufacturing soft photolithography seals, and specifically to a preparation method of a soft photolithography seal that fits a curved object without external force, as well as its products and applications.

Background technique

Microstructure processing technology is the foundation of modern high-end manufacturing and has significant demand in aerospace, microelectronics industry, computer chips, optical instruments and other fields.

Currently, photolithography is a commonly used micromachining technology with the advantages of high precision and high throughput. The process flow usually includes: (1) photoresist spin coating; (2) exposure of the area under the mask; (3) developer development. For example, the Chinese patent with publication number CN116136651A discloses a method for improving photoresist bleaching during wafer development, which includes the following steps: (1) Place the wafer in an oven in an HMDS atmosphere, and form a layer of thickness on the surface of the wafer. The HMDS mucosa of 5 to 30 nanometers is used as a photoresist tackifier; (2) spin-coat the photoresist film on the HMDS mucosa formed on the wafer surface, and then dry and solidify; (3) use step scanning The formula I line photolithography machine exposes the photoresist film; (4) Spin and wash the wafer surface, rotate the developer solution all over the photoresist film surface and soak it, spin and shake off the developer solution, and spin and wash again; repeat Perform steps (1) and (4). This multi-step process often takes a long time. At the same time, the photoresist is difficult to hang on the three-dimensional curved surface, resulting in photolithography only suitable for microstructure processing of flat objects. More importantly, the development process requires continuous flushing of the photolithography surface with a developer to wash away excess photoresist, which inevitably produces a large amount of wastewater, has a negative impact on the environment, and does not meet the requirements of ecological civilization construction. Therefore, how to achieve microstructure processing of three-dimensional curved surfaces without using photoresist has become a research focus.

Soft lithography is an emerging microstructure processing technology. Its material basis is a microstructured cross-linked silicone rubber (polydimethylsiloxane) seal. The stamp can be attached to the surface of the target object or infused with the target resin liquid to achieve microstructure manufacturing of the material. For example, the Chinese patent with publication number CN1686781A discloses a method for preparing epoxy resin microstructure devices. It uses silicone rubber (PDMS) elastic material as a micro-replication mold and utilizes its reversible and repeated deformation without permanent damage to ensure high performance. Really copy the microstructure: first use ultraviolet lithography, silicon deep reactive ion etching technology or electroforming process to transfer the microstructure pattern on the mask to the photoresist substrate, silicon or metal to obtain a micro-replication template, and then Silicone rubber and cross-linking agent are mixed in proportion, and micro-replication technology is used to copy the microstructure pattern on the template to the silicone rubber sheet. Then the epoxy resin prepolymer is mixed with the cross-linking agent and poured onto the silicone rubber mold to complete the cycle. Replication of oxy resin microstructures.

It can be found that this technology no longer requires liquid photoresist and does not require development. At the same time, using the elasticity of silicone rubber, the stamp can be attached to the surface of a curved object under the action of external force, realizing the microstructure manufacturing of non-planar substrates. However, once the external force is removed, the elastic seal quickly recovers due to the entropic driving force, causing the entire process to require continuous application of external force. On the other hand, the elastic seal needs to be obtained by pouring, curing and peeling off the silicone rubber synthetic liquid on a microstructure-containing master.

However, the manufacturing of masters relies on photolithography technology, so soft photolithography is considered a derivative process of existing photolithography technology and cannot overcome the shortcomings of photolithography in a real sense. Therefore, how to overcome the dependence of the preparation of elastic seals on photolithography technology so that soft photolithography can become an independent micro-processing method is an urgent technical problem that needs to be solved in this field.

Contents of the invention

The object of the present invention is to provide a method for preparing a soft photolithography seal that fits a curved object without external force, as well as its products and applications. This method directly uses ultraviolet light to initiate and does not require external force to obtain a soft photolithography seal. The soft light obtained The engraved seal can be reused and can be used for micro-machining of curved surfaces.

The present invention provides the following technical solutions:

A method for preparing a soft photolithography seal that fits a curved object without external force. The preparation method includes the following steps:

(1) Synthesize a cross-linked polymer material containing both a light-sensitive structure and a metal ion-coordinating structure, and swell it in a solvent;

(2) The surface of the cross-linked polymer material is covered with an optical mask with a specific light-transmitting pattern, and causes changes in the regional chemical structure under light, causing microstructure to appear on the surface of the cross-linked polymer material, and a soft photolithography seal is obtained.

The main principle of the present invention is as follows: a cross-linked polymer material containing both a light-sensitive structure and a metal ion-coordinating structure is used. Regional illumination causes changes in the internal light-sensitive structure, leading to the rearrangement of the internal network topology of the material, resulting in a decrease in cross-linking density and osmotic pressure, inducing the migration and enrichment of surrounding liquid to the exposed area, thereby bulging and producing microstructures (i.e., microstructures on the surface of the seal). The structure arises from the light-induced migration of liquid within the material). The entire process does not require the use of photolithography masters, and there are no external additives and no waste, showing high efficiency and green characteristics.

In step (1), the cross-linked polymer material contains both a light-sensitive structure and a metal ion coordination structure, wherein the light-sensitive structure can be selected from disulfide bonds, allyl sulfide bonds, o-nitrobenzene One or more types of bonds; the metal ion coordination structure can be selected from one or more types of carboxyl groups, terpyridinyl groups, and sulfhydryl groups.

Preferably, the synthetic raw materials containing light-sensitive structures used can be selected from, but are not limited to, N,N'-bisacryloylcystine, 2-methyl-propane-1,3-bis(thioethyl acrylate), acrylic acid O-nitrobenzyl ester.

Preferably, the synthetic material capable of metal ion coordination structure can be selected from, but is not limited to, acrylic acid, terpyridyl acryloyl polycaprolactone, and mercaptoethyl acrylate.

In step (1), the solvent may be selected from water or non-aqueous solvents.

Preferably, water, dimethyl sulfoxide, ethyl acetate, N,N-dimethylformamide, and glycerin can be selected.

In step (2), the wavelength of the illumination is selected from the ultraviolet band of 200-380 nm, the intensity of the illumination is greater than 10 mW/cm ² , and the illumination time is greater than 5 s.

As a preferred option, the wavelength of illumination can be 254-365nm, the intensity of illumination can be 20-50mW/cm ² , and the illumination time can be 0.5-1min.

In step (2), exposure to light can cause changes in the light-sensitive structure of the cross-linked polymer material. The mechanism for different light-sensitive structures is: disulfide bonds or allyl sulfide bonds undergo covalent bond regeneration under light exposure. row; o-nitrophenyl group undergoes isomeric dissociation under illumination. Light exposure can cause changes in the light-sensitive structure contained in the cross-linked polymer material, which will induce the internal liquid to migrate to the illuminated area, thereby bulging and producing microstructures.

The invention provides a method for preparing a soft photolithography seal that adheres to a curved object without external force. The process is efficient, green and environmentally friendly, and provides a new idea for soft photolithography on the surface of a curved object.

The invention also provides a soft photolithography seal obtained according to the above preparation method.

An application of the soft photolithography seal obtained by the above preparation method in soft photolithography. The soft photolithography method is:

According to the surface morphology of the target object, the initial shape of the soft photolithography seal is deformed into a matching three-dimensional shape, and the shape is fixed by soaking in a metal ion solution. At this time, the soft photolithography seal can fit the surface of the target object without external force. Realize structural processing of curved surfaces.

Further, the metal ions are selected from one or more of iron ions, zinc ions, cobalt ions, nickel ions or zirconium ions.

Preferably, the salt containing metal ions may be selected from one or more of iron sulfate, zinc sulfate, cobalt chloride, nickel nitrate, and zirconyl chloride. Further preferably, the concentration of the salt solution can be selected from 0.001-0.1 mol/L.

Furthermore, the shape-fixed soft photolithography seal can return to the original shape of the soft photolithography seal after being soaked in a solution containing a chelating agent.

Further, the chelating agent is selected from one or both of ethylenediaminetetraacetic acid or sodium citrate.

Further preferably, the chelating agent solution concentration can be selected from 0.01-1 mol/L.

Facing the need for micro-processing of curved objects, the above-mentioned soft lithography method provided by the present invention can attach a soft lithography seal containing microstructure to the surface of the target object, soak it in a salt solution containing metal ions, and utilize the coordination effect The soft photolithography stamp is fixed into a shape that matches the surface of the target object, so that the fit and soft photolithography of curved objects can be achieved without external force. Moreover, after the soft photolithography stamp is fixed in a specific shape/deformation and soaked in a solution containing a chelating agent, it can return to its original shape before being fixed due to the destruction of coordination bonds, so it can be reused for objects with different surface morphologies. Soft lithography/micromachining.

The invention also provides an application of the soft photolithography seal obtained by the above preparation method in microstructure replicating of polymer resin.

The invention also provides an application of the soft photolithography stamp obtained by the above preparation method in regional etching on the surface of a curved object.

The present invention uses a cross-linked polymer material containing a light-sensitive structure and a metal ion coordination structure to cause changes in the internal topological structure of the material under the action of ultraviolet light, thereby preparing a soft photolithography seal. And the shape of the soft photolithography seal can be further fixed by soaking metal ions, and the fixed soft photolithography seal can be restored by chelating by soaking the chelating solution. The method provided by the invention does not require external force or photolithography master, and the process is simple, easy to operate, and green and environmentally friendly.

Compared with the existing technology, the benefits of the present invention are reflected in:

(1) The elastic seal (soft photolithography seal) in the present invention can be obtained directly by ultraviolet light without external force, and the process is simple;

(2) Since the cross-linked polymer material used in the present invention contains both a light-sensitive structure and a metal ion coordination structure, through repeated interactions, the soft photolithography seal prepared in the present invention can be reused;

(3) In the present invention, the soft photolithography stamp is obtained through the self-growth of microstructures and does not rely on other types of re-engraving or photolithography, thus avoiding the shortcomings of photolithography itself.

Description of drawings

Figure 1 is a schematic diagram of the preparation method of a soft photolithography seal that fits a curved object without external force according to the present invention;

Figure 2 is a macroscopic schematic diagram of the soft photolithography seal prepared in Example 1 of the present invention;

Figure 3 is a three-dimensional white light interference micrograph of the surface microstructure of the soft photolithography seal prepared in Example 1 of the present invention;

Figure 4 is a macro view of the soft photolithography seal prepared in Example 1 of the present invention attached to the surface of a glass product without external force;

Figure 5 is a macroscopic view of the soft photolithography seal prepared in Example 1 of the present invention being reattached to the surface of a wooden product without external force;

Figure 6 is a macroscopic view of the soft photolithography seal prepared in Example 2 of the present invention being fixed into a specific three-dimensional shape and restored;

Figure 7 is a three-dimensional white light interference micrograph of the surface microstructure of the soft photolithography seal prepared in Example 2 of the present invention;

Figure 8 is a three-dimensional white light interference micrograph of the surface microstructure of the soft photolithography seal prepared in Example 3 of the present invention;

Figure 9 is a three-dimensional white light interference micrograph of the surface microstructure of the soft photolithography seal prepared in Example 4 of the present invention;

Figure 10 is a three-dimensional white light interference micrograph of the surface microstructure of the soft photolithography seal prepared in Example 5 of the present invention;

Figure 11 is a microstructure diagram of the soft photolithography seal prepared in Example 5 of the present invention to achieve soft photolithography of optically transparent resin.

Detailed ways

The present invention will be described in further detail below with reference to the accompanying drawings and examples. It should be noted that the following examples are intended to facilitate the understanding of the present invention and do not limit it in any way.

As shown in Figure 1, the key to the preparation of the soft photolithography stamp provided by the present invention that can fit a curved surface without external force is that the cross-linked polymer material network contains both a light-sensitive structure and a metal ion-coordinating structure. It can be seen from the basic principles that the prepared cross-linked polymer material contains a light-sensitive structure. Under the stimulation of an external light source, the internal chemical topology of the material is rearranged, which in turn affects the cross-linking density and osmotic pressure of the exposed area of the material, resulting in The liquid migrates to the illuminated area to create microstructures and obtain the desired soft photolithography stamp. In addition, due to the existence of metal ion coordination structures within the cross-linked polymer material, the prepared elastic stamp can be repeatedly attached to objects with different surface morphologies without external force, achieving soft lithography goals.

Example 1 (disulfide bond system + carboxylic acid coordination)

First, prepare the polymer cross-linking agent containing disulfide bonds—sodium N, N’-diacryloylcystine. The raw materials used are shown in Table 1:

Table 1 Raw materials used to prepare disulfide cross-linking agents

raw material supply company sodium hydroxide Sinopharm L-cystine Aladdin Company Methanol Sinopharm Acryloyl chloride Merrill Corporation Ether Sinopharm

Preparation:

Step 1: Dissolve 10g sodium hydroxide in 350mL methanol to obtain an alkaline methanol solution;

Step 2: Dissolve 13.5g L-cystine in alkaline methanol and stir thoroughly to dissolve;

Step 3: In an ice-water bath, add 11 mL of acryloyl chloride dropwise to the above-mentioned alkaline solution containing L-cystine, and the dropping time is 20 minutes or more;

Step 4: The reaction lasts for 12 hours, centrifuge to remove the solid by-products and retain the transparent solution;

Step 5: Precipitate the transparent solution in anhydrous ether, centrifuge the obtained solid precipitate from the solution, and place it in a vacuum oven to dry at room temperature for one day to obtain the required substance - N,N'-diacryloylcysteine. sodium bisulfate.

The molecular formula of N,N’-bisacryloylcystine sodium (BISS) is as follows:

Table 2 Example 1 Raw materials for preparing cross-linked polymers

Preparation:

Step 1: Dissolve 2.5g acrylamide and 1g BISS in 25mL deionized water;

Step 2: Add 500 μL of 4% APS aqueous solution and 50 μL TEMED into the solution, stir evenly, quickly transfer to the mold, and react at room temperature for 24 hours to completely cross-link it to obtain a cross-linked polymer material.

Step 3: Take out the obtained cross-linked polymer material, soak it in deionized water for one day, remove incompletely reacted substances, and then soak it in 1 mg/mL 2-hydroxy-4'-(2-hydroxyethoxy )-2-Methylpropiophenone (I2959) aqueous solution for later use.

Step 4: Cover the surface of the cross-linked polymer material with an optical mask with a specific light-transmitting pattern, and expose it to ultraviolet light for 2 minutes to cause changes in the regional chemical structure, causing microstructure to appear on the surface of the material, and obtaining a soft photolithography seal.

Step 5: Fit the soft seal to the surface of the target object, deform it into a matching three-dimensional shape, and fix it by soaking in 0.01mol/L ferric chloride solution. It can be attached to the surface of the glass product without external force to achieve soft sealing. photolithography;

Step 6: Soak the used soft seal in 0.01mol/L sodium citrate solution for 24 hours, which can restore the soft seal to its original shape, and through renewed ion fixation, it can be attached to the surface of the wood product again. Implement soft lithography.

The soft photolithography seal prepared in Example 1 is shown in Figure 2. The optical mask used to prepare the soft photolithography seal has a grid structure. The lines used in the grid are opaque and the intersection areas are light-transmissive and can be illuminated under ultraviolet light. Then the microstructure grows by itself. The three-dimensional white light interference micrograph of the surface microstructure of the soft photolithography seal prepared in Example 1 is shown in Figure 3. The optical mask used to prepare the soft photolithography seal has equidistant stripes. The soft photolithography seal prepared in Example 1 is attached to the surface of the glass product without external force, as shown in Figure 4. The left side is the prepared soft photolithography seal. The seal is attached to the surface of the glass product, and the whole is soaked in After 24 hours in ferric chloride solution, the soft photolithography seal on the right can be fixed. Soak the fixed soft photolithography seal in Figure 4 in sodium citrate solution for 24 hours. The soft photolithography seal can return to its original state, as shown in Figure 5. The soft photolithography seal that has returned to its initial state can be attached to the surface again without external force. Wooden surfaces and can be fixed again.

Example 2 (allyl sulfide system + carboxylic acid coordination)

In this example, a cross-linked polymer material containing an allyl sulfide structure was prepared. The raw materials used are as shown in Table 3:

Table 3 Example 2 Raw materials for preparing cross-linked polymers

The molecular formula of pentaerythritol tetrakis(3-mercaptopropionate) (PETMP) is as follows:

The molecular formula of ethylene glycol dimercaptopropionate (EGDMP) is as follows:

The molecular formula of 2-methylene-propane-1,3-bis(thioethyl acrylate) (MBTA) is as follows:

Preparation:

Step 1: Dissolve 10g PETMP and 30g EGDMP in 100mL glycerin, dissolve 0.5g I819 and 1g I651 in the above solution, add 8.5g MBTA and 10g sodium acrylate to obtain a homogeneous organic solution;

Step 2: Add 5g triethylamine to the above homogeneous organic solution, stir evenly, place it in a glass slide mold, and cure for 24 hours to obtain a cross-linked polymer;

Step 3: Fully swell the obtained cross-linked polymer in a glycerol solution of 1 mg/mL I819;

Step 4: Place an optical mask with a specific light-transmitting pattern on the surface of the resulting cross-linked polymer and illuminate it with a UV mercury lamp for 10 minutes. Through internal liquid migration, a soft photolithography stamp with a certain surface microstructure is obtained;

Step 5: The obtained soft photolithography stamp is formed into a specific shape and immersed in a zinc sulfate glycerin solution for fixation. It can be deformed into a three-dimensional shape.

Among them, the soft photolithography seal prepared in Example 2 is fixed into a specific three-dimensional shape and restored as shown in Figure 6. First, the soft photolithography seal is cut into a rectangular strip and bent into a "6" shape, and then soaked in sulfuric acid. The zinc-glycerol solution is used to fix the shape, and the shape can be further restored to the original state by chelating solution. The three-dimensional white light interference micrograph of the surface microstructure of the soft photolithography seal prepared in Example 2 is shown in Figure 7. The optical mask used to prepare the soft photolithography seal has equidistant stripes. .

Example 3 (disulfide bond system + terpyridine coordination)

In this example, a cross-linked polymer material containing terpyridine coordination groups was prepared. The raw materials used are as shown in Table 4:

Table 4 Example 3 Raw materials for preparing cross-linked polymers

Preparation:

Step 1: React 20g ε-caprolactone, 2g 1,5,7 triazabicyclo[4.4.0]dec-5-ene, and 20g terpyridine at 120°C in a nitrogen atmosphere for 10 hours, and dissolve the polymer into toluene neutralize and precipitate in cold methanol, and the resulting product is dried under vacuum at room temperature overnight to obtain terpyridine-terminated polycaprolactone;

Step 2: Dissolve 20g of the terpyridine-terminated polycaprolactone obtained in step 1, 1.08g of acryloyl chloride, and 1.22g of triethylamine in 100 mL, react at 80°C for 20 hours, and add the reacted mixed solution in cold ethanol Precipitate in the medium, and dry the obtained solid under vacuum at room temperature for 24 hours to obtain the desired polymerizable monomer TPyA containing a terpyridine group. The reaction equation is as follows;

Step 3: Dissolve 0.5g TPyA, 10.0g isopropylacrylamide, and 0.1g BISAC in 10g DMF, then add 0.1g BPO, and react at 80°C for 10 hours.

The molecular formula of N,N’-bisacrylcystine (BISAC) is as follows:

Step 4: Fully swell the obtained cross-linked polymer in DMF containing 1 mg/mL I819;

Step 5: Place a mask with a certain light-transmitting pattern on the polymer and illuminate it with UV light for 1 minute to obtain a soft photolithography template.

The three-dimensional white light interference micrograph of the surface microstructure of the soft photolithography seal prepared in Example 3 is shown in Figure 8. The optical mask used to prepare the soft photolithography seal is an opaque circular shape.

Example 4 (o-nitrobenzene system + carboxylic acid coordination)

In this example, a cross-linked polymer material containing an o-nitrobenzene photosensitive structure was prepared. The raw materials used are as shown in Table 5:

Table 5 Example 4 Raw materials for preparing cross-linked polymers

Preparation:

Step 1: Dissolve 15g o-nitrobenzyl alcohol and 10g sodium acrylate in 150mL methylene chloride, add 14.4mL triethylamine, the reaction solution becomes clear and cooled to 10°C;

Step 2: Add 8.5 mL acryloyl chloride dropwise to the clear solution obtained in step 1. The reaction is stirred at room temperature for 24 hours. After filtering the solid by-product, wash the above-mentioned clear solution with deionized water and brine respectively, and absorb excess with anhydrous magnesium sulfate. of water, filter to obtain the clear liquid, and evaporate the solvent to obtain the final light yellow product (NA), with the following molecular formula;

Step 3: Thoroughly mix 1g NA, 5g N,N-dimethylacrylamide, 100mg ethylene glycol dimethacrylate, 100mg I819 and 1.6mg light absorber carmine and cure under visible light for 5 minutes, then you will get The solid polymer was swollen in dimethyl sulfoxide for 24 h to remove unreacted components and simultaneously swell the cross-linked polymer.

Step 4: Place the cross-linked polymer under a photomask with a certain pattern and expose it to UV light for 30 minutes. As the osmotic pressure of the exposed area increases, the surrounding liquid migrates to this area, and finally a soft photolithography seal is obtained.

The three-dimensional white light interference micrograph of the surface microstructure of the soft photolithography seal prepared in Example 4 is shown in Figure 9. The optical mask used to prepare the soft photolithography seal is "S-S".

Example 5 (disulfide bond system + thiol coordination)

In this embodiment, a cross-linked polymer material containing a thiol coordination structure is prepared, and the raw materials used are as shown in Table 6:

Table 6 Example 5 Raw materials for preparing cross-linked polymers

Preparation:

Step 1: Add 25g HEA, 2.5g mercaptoethyl acrylate, 0.25g BISAC, and 0.25g AIBN into the beaker and stir evenly;

Step 2: Pour the mixture into the mold and polymerize at 70°C for 5 hours;

Step 3: Demold the cross-linked polymer and soak it in liquid paraffin containing 2 mg/mL I819 for 48 hours;

Step 4: Place a photomask with a certain pattern on the surface of the swollen cross-linked polymer and expose it to UV light for 60 minutes to obtain a soft photolithography template with a microstructure.

Step 5: Coat the surface of the obtained soft photolithography seal with an optically transparent resin precursor (formula: 16g isobornyl acrylate, 8g 2-phenoxyethyl acrylate, 0.5g 1,6-hexanediol diacrylate, 0.75g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide), UV irradiation for 2 minutes, and peeling off to obtain an optically transparent resin with a specific microstructure on the surface, which can realize the manufacture of microlens arrays .

The three-dimensional white light interference micrograph of the surface microstructure of the soft lithography seal prepared in Example 5 is shown in Figure 10. The soft lithography template is prepared by superposing two stripes, indicating that the materials used in the present invention can be superimposed. The microstructure of the soft photolithography seal prepared in Example 5 to achieve soft photolithography of optically transparent resin is shown in Figure 11. The left side is the soft photolithography seal with a hexagonal honeycomb structure grown through the optical mask, and the right side is The side is a soft photolithography material obtained by casting optical resin on the stamp, curing it, and peeling it off.

Claims (10)

1. A method for preparing a soft photolithography seal that fits a curved object without external force, characterized in that the preparation method includes the following steps: (1) Synthesize a cross-linked polymer material containing both a light-sensitive structure and a metal ion-coordinating structure, and swell it in a solvent; (2) The surface of the cross-linked polymer material is covered with an optical mask with a specific light-transmitting pattern, and causes changes in the regional chemical structure under light, causing microstructure to appear on the surface of the cross-linked polymer material, and a soft photolithography seal is obtained. 2. The method for preparing a soft photolithographic seal that fits a curved object without external force according to claim 1, characterized in that in step (1), the cross-linked polymer material contains both a light-sensitive structure and It can be a metal ion coordination structure, wherein the light-sensitive structure can be selected from one or more of disulfide bonds, allyl sulfide bonds, and o-nitrobenzene bonds; the metal ion coordination structure can be selected from carboxyl, triple One or more of pyridyl and mercapto groups. 3. The method for preparing a soft photolithography seal that fits a curved object without external force according to claim 1, characterized in that in step (2), the wavelength of the illumination is selected from the ultraviolet band of 200-380nm, The intensity of light is greater than 10mW/cm ² and the time of light is greater than 5s. 4. A soft photolithography seal obtained by the preparation method according to any one of claims 1-3. 5. The application of the soft photolithography seal according to claim 4, wherein the soft photolithography method is: According to the surface morphology of the target object, the initial shape of the soft photolithography seal is deformed into a matching three-dimensional shape, and the shape is fixed by soaking in a metal ion solution. At this time, the soft photolithography seal can fit the surface of the target object without external force. Realize structural processing of curved surfaces. 6. Application of soft photolithography seal according to claim 5, characterized in that the metal ions are selected from one or more of iron ions, zinc ions, cobalt ions, nickel ions or zirconium ions. 7. The application of the soft photolithography seal according to claim 5, characterized in that the soft photolithography seal with a fixed shape can return to the initial shape of the soft photolithography seal after being immersed in a solution containing a chelating agent. 8. The application of soft photolithography seal according to claim 7, characterized in that the chelating agent is selected from one or both of ethylenediaminetetraacetic acid or sodium citrate. 9. Application of the soft photolithography seal according to claim 4 in microstructure replicating of polymer resin. 10. The application of the soft photolithography stamp according to claim 4 in area etching on the surface of a curved object.