A micro-contact printing method based on cell backpacks

Abstract

The application provides a micro-contact transfer method based on cell back-packing, comprising the following steps: S1. coating an organic adhesion layer on a glass plate, drying by heating to obtain an adhesion material; S2. placing the glass plate on a heating table to heat, and adhering a stamp with a spin-coated cell back-packing to one side of the glass plate containing the adhesion material; S3. applying a certain pressure to the stamp to transfer the cell back-packing, so that the cell back-packing is conformally contacted with the adhesion material; S4. separating the stamp and the cell back-packing by peeling to leave regular cell back-packings on the adhesion material, that is, the micro-contact transfer of the cell back-packing is completed. The micro-contact transfer method based on the cell back-packing has a relatively simple process, reduced operation difficulty, reduced human error, is convenient to popularize and apply, and is expected to be used for large-scale production and manufacturing.

Description

Technical Field

[0001] This invention relates to the field of pore sealing of graphite materials, and more specifically to a micro-contact transfer method based on a cell backpack. Background Technology

[0002] Transfer printing is an emerging technology for micro and nanofabrication. It uses a soft, flexible polymer stamp to transfer materials from one substrate to another, and can be applied in various fields such as biomedicine, electronics manufacturing, and materials science. Furthermore, transfer printing technology is highly flexible and scalable, allowing processing on substrates of different materials, sizes, and shapes.

[0003] By transforming transfer printing into micro-contact transfer printing technology at the micrometer level, this technology can be applied to higher-precision devices. Compared to traditional transfer printing, it offers advantages such as higher precision, smaller size, and greater quantity. Micro-contact transfer printing is a technique used to create micrometer-scale patterns on solid surfaces.

[0004] In the past, microcontact transfer technology for cell backpacks has been fraught with uncertainties, making its improvement a significant challenge. Traditional microcontact transfer techniques require placing the cell backpack stamp directly onto a glass plate coated only with polyvinyl alcohol (PVA) on a heated plate, adding weights for a period, and then peeling off the stamp. Alternatively, the PVA-coated glass plate can be placed in a water bath and preserved for a period before the cell backpack stamp is directly applied to it. This results in inconsistent microcontact transfer efficiency and higher raw material consumption. The emergence of optimized microcontact transfer technologies has improved efficiency to some extent, mitigating this challenging situation.

[0005] PDMS, a flexible stamp material, is the most commonly used flexible stamp material in microcontact transfer technology. It possesses excellent elasticity and flexibility, enabling it to make close contact with the substrate surface without damaging it. Furthermore, it is biocompatible and biodegradable, making it widely used in the biomedical field. PDMS can also be fabricated into stamps of various shapes and sizes using simple photolithography techniques to meet diverse transfer needs.

[0006] Self-assembled monolayer technology is one of the important foundations of microcontact transfer technology. A self-assembled monolayer is an ordered monolayer structure spontaneously formed on a substrate surface by molecules through chemical bonding or physical adsorption. It allows for the modification and control of the material surface at the molecular level, offering high selectivity and controllability. This technology can form specific chemical functional groups or patterns on the substrate surface, providing excellent templates for microcontact transfer.

[0007] Surface science has conducted in-depth research on the physical and chemical properties of material surfaces, providing a theoretical foundation for microcontact transfer technology. For example, studies on surface energy, wettability, and interactions can further optimize the transfer process. Improvements to transfer technology can significantly enhance the transfer efficiency of cell backpacks. Therefore, it is necessary to invent a novel microcontact transfer method based on cell backpacks to address the aforementioned challenges. Summary of the Invention

[0008] Technical problem to be solved: The purpose of this invention is to provide a micro-contact transfer technology with good adhesion performance, high chemical stability, strong adhesion to the surface of the transferred material, and simple steps, so as to optimize the current micro-contact transfer method for cell backpacks.

[0009] Technical solution: A microcontact transfer method based on a cell backpack, comprising the following steps:

[0010] S1. The organic adhesive layer is coated onto a glass plate and heated to dry, thus obtaining the adhesive material;

[0011] S2. Place the glass plate on the heating table and heat it. Then, attach the stamp with the spin-coated cell backpack to the side of the glass plate containing the adhesive material.

[0012] S3. Apply a certain pressure to the stamp to imprint the cell backpack, so that the cell backpack makes conformal contact with the adhesive material;

[0013] S4. The stamp and the cell backpack are broken and separated by peeling, leaving the regular cell backpack on the adhesive material, thus completing the micro-contact transfer of the cell backpack.

[0014] Preferably, in step S1, the organic adhesive coating is a mixture of PVA, a hydroxyl-containing polar solvent, and water, wherein the content of PVA in the mixture is 2.5-3.5 wt%, and the content of the hydroxyl-containing polar solvent is 5-9 wt%.

[0015] Preferably, the hydroxyl-containing polar solvent is ethylene glycol.

[0016] Preferably, the heating temperature in step S2 is 60-70℃.

[0017] Preferably, the pressure in step S3 is 3200.0 Pa to 5500.0 Pa, and the pressure is applied for 50 to 70 seconds.

[0018] Preferably, the stamp is a PDMS raised array mold, and the diameter, height and spacing of the cylindrical raised protrusions on the PDMS raised array mold are all 3-15μm.

[0019] Preferably, the cell backpack material includes a support layer and an adhesive layer. The support layer is a polylactic acid-glycolic acid copolymer, and the adhesive layer is a mixture of polyallylamine hydrochloride and hyaluronic acid aldehyde. The adhesive layer and the support layer are sequentially spin-coated onto a micron-scale micropillar matrix structure with periodic arrangement on the surface of a PDMS protrusion array mold.

[0020] Beneficial effects: The microcontact transfer method of the present invention has the following advantages:

[0021] 1. The organic coating used in this invention is a mixed solution of PVA and ethylene glycol. Ethylene glycol is an organic compound that is miscible with water and acetone, and also has some solubility in ethers. Chemically, ethylene glycol is relatively stable and contains two hydroxyl groups, giving it excellent hydrophilicity. The hydroxyl groups in the PVA aqueous solution form hydrogen bonds with the polar solvent ethylene glycol, making the intermolecular interactions tighter and increasing the viscosity of the PVA aqueous solution. Upon heating, the movement of the PVA molecular chains intensifies, and ethylene glycol acts as a plasticizer. It can insert into the spaces between PVA molecular chains, changing the intermolecular forces and increasing the flexibility and fluidity of the molecular chains to a certain extent, allowing the PVA to better entangle itself under heating, thus exhibiting stronger viscosity.

[0022] 2. This invention adds ethylene glycol to the original PVA organic adhesive coating, which further improves the original method that required water bath heating, achieves quantitative control of temperature and water, improves the current transfer efficiency, ensures a high success rate of backpack transfer, maintains the transfer efficiency at 80%-90%, prevents the large loss of previous backpacks, and promotes further experiments.

[0023] 3. The micro-contact transfer technology based on cell backpacks in this invention has a relatively simple process, reduced operational difficulty, reduced human error, and is easy to promote and apply, and is expected to be used for large-scale production.

[0024] 4. The process of this invention can be used for transfer operations between various materials, and has strong scalability; moreover, this invention has high repeatability and can be reproduced multiple times, and the time required for each transfer is very short, which can greatly improve work efficiency. Attached Figure Description

[0025] Figure 1 This is a front view schematic diagram of the cell backpack stamp coated with an organic adhesive coating in this invention;

[0026] Figure 2 This is a top view of the backpack attached to the organic adhesive coating after micro-contact transfer in this invention.

[0027] Figure 3 This is a front view schematic diagram of the backpack attached to the organic adhesive coating after micro-contact transfer in this invention;

[0028] Figure 4 This is a schematic diagram of the stamp being printed on an organic adhesive coating in this invention;

[0029] Figure 5 This is a schematic diagram of the entire micro-contact transfer process in this invention;

[0030] Figure 6 Fluorescence microscopy image of cell backpacks transferred onto an organic adhesive coating;

[0031] Figure 7 The images are fluorescence micrographs of the transfer onto the organic adhesive coating at different heating temperatures in Comparative Example 1 and Comparative Example 2, where A is the fluorescence micrograph of Comparative Example 1 and B is the fluorescence micrograph of Comparative Example 2.

[0032] Figure 8 The images are fluorescence micrographs of the transfer onto the organic adhesive coating under different applied pressures in Comparative Example 3 and Comparative Example 4, where A is the fluorescence micrograph of Comparative Example 3 and B is the fluorescence micrograph of Comparative Example 4.

[0033] Figure 9 The images are fluorescence micrographs of the transfer onto the organic adhesive coating at different times in Comparative Examples 5 and 6, where A is the fluorescence micrograph of Comparative Example 5 and B is the fluorescence micrograph of Comparative Example 6.

[0034] Figure 10 The images shown are fluorescence micrographs of the same organic adhesive coating with different concentrations of ethylene glycol in Comparative Example 7 and Comparative Example 8, where A is the fluorescence micrograph of Comparative Example 7 and B is the fluorescence micrograph of Comparative Example 8.

[0035] Figure 11 The images shown are fluorescence micrographs of the transfer onto the organic adhesive coating when using different organic adhesive coating materials in Examples 9-12. In the examples, A is a fluorescence micrograph of the organic adhesive coating consisting only of PVA; B is a fluorescence micrograph of the organic adhesive coating consisting of propylene glycol; C is a fluorescence micrograph of the organic adhesive coating consisting of butanediol; and D is a fluorescence micrograph of the organic adhesive coating consisting of glycerol.

[0036] Figure 12 A comparison of the number of cell backpacks transferred under the same transfer conditions, with different concentrations of ethylene glycol in the same organic adhesive coating.

[0037] Figure 13 A comparison of the number of cell backpacks transferred at different heating temperatures, assuming all other transfer conditions are the same.

[0038] Figure 14 A comparison of the number of transferred cell backpacks under different applied pressures, assuming all other transfer conditions are the same.

[0039] Figure 15 A comparison chart of the number of transferred cell backpacks at different transfer times, assuming all other transfer conditions are the same.

[0040] Figure 16 A comparison of the number of cell backpacks transferred under different organic adhesive coatings, assuming all other transfer conditions are the same.

[0041] In the diagram, 1-glass plate; 2-cell backpack stamp; 3-weights; 4-heating platform; 5-organic adhesive coating; 6-cell backpack. Detailed Implementation

[0042] The present invention will be further described below with reference to the embodiments and accompanying drawings. The following embodiments are illustrative of the present invention, but the present invention is not limited to the following embodiments:

[0043] Reference Figure 1 , Figure 2 and Figure 3 The cell backpack stamp 2 in the micro-contact transfer method has a micron-scale micropillar matrix structure with periodically arranged micron-scale micropillars on its surface, and the force between the micron-scale micropillars and the organic adhesive coating 5 on the surface of the glass plate 1 is sufficient to adhere the cell backpack 6 to the surface of the organic adhesive coating 5 on the glass plate 1.

[0044] Example 1

[0045] A microcontact transfer method based on a cell backpack includes the following steps:

[0046] S1. Dissolve PVA in deionized water and mix thoroughly in a magnetically stirred water bath at 60°C. Then, add ethylene glycol to the solution and stir until homogeneous to obtain an organic adhesion layer, wherein the content of PVA is 2.5 wt% and the content of ethylene glycol is 5 wt%.

[0047] S2. The organic adhesive layer is coated onto a glass plate and dried at 60°C for 1 hour to obtain the adhesive material;

[0048] S3. Place the glass plate on the heating table and heat it to 60°C. Then, attach the stamp with the spin-coated cell backpack to the side of the glass plate containing the adhesive material.

[0049] S4. Apply pressure of 3200.0 Pa to the stamp for 70 s to imprint the cell backpack, so that the cell backpack and the adhesive material make conformal contact.

[0050] S5. The stamp and the cell backpack are broken and separated by peeling, leaving the regular cell backpack on the adhesive material, thus completing the micro-contact transfer of the cell backpack.

[0051] Example 2

[0052] A microcontact transfer method based on a cell backpack includes the following steps:

[0053] S1. Dissolve PVA in deionized water and mix thoroughly in a magnetically stirred water bath at 60°C. Then, add ethylene glycol to the solution and stir until homogeneous to obtain an organic adhesion layer, wherein the content of PVA is 3.5 wt% and the content of ethylene glycol is 9 wt%.

[0054] S2. The organic adhesive layer is coated onto a glass plate and dried at 60°C for 1 hour to obtain the adhesive material;

[0055] S3. Place the glass plate on the heating table and heat it to 70°C. Then, attach the stamp with the spin-coated cell backpack to the side of the glass plate containing the adhesive material.

[0056] S4. Apply pressure of 5500.0 Pa to the stamp for 50 s to imprint the cell backpack, so that the cell backpack and the adhesive material make conformal contact.

[0057] S5. The stamp and the cell backpack are broken and separated by peeling, leaving the regular cell backpack on the adhesive material, thus completing the micro-contact transfer of the cell backpack.

[0058] Example 3

[0059] A microcontact transfer method based on a cell backpack includes the following steps:

[0060] S1. Dissolve PVA in deionized water and mix thoroughly in a magnetically stirred water bath at 60°C. Then, add ethylene glycol to the solution and stir until homogeneous to obtain an organic adhesion layer, wherein the content of PVA is 2.8 wt% and the content of ethylene glycol is 6 wt%.

[0061] S2. The organic adhesive layer is coated onto a glass plate and dried at 60°C for 1 hour to obtain the adhesive material;

[0062] S3. Place the glass plate on the heating table and heat it to 65°C. Then, attach the stamp with the spin-coated cell backpack to the side of the glass plate containing the adhesive material.

[0063] S4. Apply pressure of 3800.0 Pa to the stamp for 55 s to imprint the cell backpack, so that the cell backpack and the adhesive material make conformal contact.

[0064] S5. The stamp and the cell backpack are broken and separated by peeling, leaving the regular cell backpack on the adhesive material, thus completing the micro-contact transfer of the cell backpack.

[0065] Example 4

[0066] A microcontact transfer method based on a cell backpack includes the following steps:

[0067] S1. Dissolve PVA in deionized water and mix thoroughly in a magnetically stirred water bath at 60°C. Then, add ethylene glycol to the solution and stir until homogeneous to obtain an organic adhesion layer, wherein the content of PVA is 3.2 wt% and the content of ethylene glycol is 7 wt%.

[0068] S2. The organic adhesive layer is coated onto a glass plate and dried at 60°C for 1 hour to obtain the adhesive material;

[0069] S3. Place the glass plate on the heating table and heat it to 65°C. Then, attach the stamp with the spin-coated cell backpack to the side of the glass plate containing the adhesive material.

[0070] S4. Apply pressure of 4500.0 Pa to the stamp for 60 s to imprint the cell backpack, so that the cell backpack and the adhesive material make conformal contact.

[0071] S5. The stamp and the cell backpack are broken and separated by peeling, leaving the regular cell backpack on the adhesive material, thus completing the micro-contact transfer of the cell backpack.

[0072] Comparative Example 1

[0073] A microcontact transfer method based on a cell backpack includes the following steps:

[0074] S1. Dissolve PVA in deionized water and mix thoroughly in a magnetically stirred water bath at 60°C. Then, add ethylene glycol to the solution and stir until homogeneous to obtain an organic adhesion layer, wherein the content of PVA is 3.2 wt% and the content of ethylene glycol is 7 wt%.

[0075] S2. The organic adhesive layer is coated onto a glass plate and dried at 60°C for 1 hour to obtain the adhesive material;

[0076] S3. Place the glass plate on the heating table and heat it to 50°C. Then, attach the stamp with the spin-coated cell backpack to the side of the glass plate containing the adhesive material.

[0077] S4. Apply pressure of 4500.0 Pa to the stamp for 60 s to imprint the cell backpack, so that the cell backpack and the adhesive material make conformal contact.

[0078] S5. The stamp and the cell backpack are broken and separated by peeling, leaving the regular cell backpack on the adhesive material, thus completing the micro-contact transfer of the cell backpack.

[0079] Comparative Example 2

[0080] A microcontact transfer method based on a cell backpack includes the following steps:

[0081] S1. Dissolve PVA in deionized water and mix thoroughly in a magnetically stirred water bath at 60°C. Then, add ethylene glycol to the solution and stir until homogeneous to obtain an organic adhesion layer, wherein the content of PVA is 3.2 wt% and the content of ethylene glycol is 7 wt%.

[0082] S2. The organic adhesive layer is coated onto a glass plate and dried at 60°C for 1 hour to obtain the adhesive material;

[0083] S3. Place the glass plate on the heating table and heat it to 80°C. Then, attach the stamp with the spin-coated cell backpack to the side of the glass plate containing the adhesive material.

[0084] S4. Apply pressure of 4500.0 Pa to the stamp for 60 s to imprint the cell backpack, so that the cell backpack and the adhesive material make conformal contact.

[0085] S5. The stamp and the cell backpack are broken and separated by peeling, leaving the regular cell backpack on the adhesive material, thus completing the micro-contact transfer of the cell backpack.

[0086] Comparative Example 3

[0087] A microcontact transfer method based on a cell backpack includes the following steps:

[0088] S1. Dissolve PVA in deionized water and mix thoroughly in a magnetically stirred water bath at 60°C. Then, add ethylene glycol to the solution and stir until homogeneous to obtain an organic adhesion layer, wherein the content of PVA is 3.2 wt% and the content of ethylene glycol is 7 wt%.

[0089] S2. The organic adhesive layer is coated onto a glass plate and dried at 60°C for 1 hour to obtain the adhesive material;

[0090] S3. Place the glass plate on the heating table and heat it to 65°C. Then, attach the stamp with the spin-coated cell backpack to the side of the glass plate containing the adhesive material.

[0091] S4. Apply pressure of 2500.0 Pa to the stamp for 60 s to imprint the cell backpack, so that the cell backpack and the adhesive material make conformal contact.

[0092] S5. The stamp and the cell backpack are broken and separated by peeling, leaving the regular cell backpack on the adhesive material, thus completing the micro-contact transfer of the cell backpack.

[0093] Comparative Example 4

[0094] A microcontact transfer method based on a cell backpack includes the following steps:

[0095] S1. Dissolve PVA in deionized water and mix thoroughly in a magnetically stirred water bath at 60°C. Then, add ethylene glycol to the solution and stir until homogeneous to obtain an organic adhesion layer, wherein the content of PVA is 3.2 wt% and the content of ethylene glycol is 7 wt%.

[0096] S2. The organic adhesive layer is coated onto a glass plate and dried at 60°C for 1 hour to obtain the adhesive material;

[0097] S3. Place the glass plate on the heating table and heat it to 65°C. Then, attach the stamp with the spin-coated cell backpack to the side of the glass plate containing the adhesive material.

[0098] S4. Apply pressure of 6500.0 Pa to the stamp for 60 s to imprint the cell backpack, so that the cell backpack and the adhesive material make conformal contact.

[0099] S5. The stamp and the cell backpack are broken and separated by peeling, leaving the regular cell backpack on the adhesive material, thus completing the micro-contact transfer of the cell backpack.

[0100] Comparative Example 5

[0101] A microcontact transfer method based on a cell backpack includes the following steps:

[0102] S1. Dissolve PVA in deionized water and mix thoroughly in a magnetically stirred water bath at 60°C. Then, add ethylene glycol to the solution and stir until homogeneous to obtain an organic adhesion layer, wherein the content of PVA is 3.2 wt% and the content of ethylene glycol is 7 wt%.

[0103] S2. The organic adhesive layer is coated onto a glass plate and dried at 60°C for 1 hour to obtain the adhesive material;

[0104] S3. Place the glass plate on the heating table and heat it to 65°C. Then, attach the stamp with the spin-coated cell backpack to the side of the glass plate containing the adhesive material.

[0105] S4. Apply pressure of 4500.0 Pa to the stamp for 30 s to imprint the cell backpack, so that the cell backpack and the adhesive material make conformal contact.

[0106] S5. The stamp and the cell backpack are broken and separated by peeling, leaving the regular cell backpack on the adhesive material, thus completing the micro-contact transfer of the cell backpack.

[0107] Comparative Example 6

[0108] A microcontact transfer method based on a cell backpack includes the following steps:

[0109] S1. Dissolve PVA in deionized water and mix thoroughly in a magnetically stirred water bath at 60°C. Then, add ethylene glycol to the solution and stir until homogeneous to obtain an organic adhesion layer, wherein the content of PVA is 3.2 wt% and the content of ethylene glycol is 7 wt%.

[0110] S2. The organic adhesive layer is coated onto a glass plate and dried at 60°C for 1 hour to obtain the adhesive material;

[0111] S3. Place the glass plate on the heating table and heat it to 65°C. Then, attach the stamp with the spin-coated cell backpack to the side of the glass plate containing the adhesive material.

[0112] S4. Apply pressure of 4500.0 Pa to the stamp for 90 s to imprint the cell backpack, so that the cell backpack makes conformal contact with the adhesive material;

[0113] S5. The stamp and the cell backpack are broken and separated by peeling, leaving the regular cell backpack on the adhesive material, thus completing the micro-contact transfer of the cell backpack.

[0114] Comparative Example 7

[0115] A microcontact transfer method based on a cell backpack includes the following steps:

[0116] S1. Dissolve PVA in deionized water and mix thoroughly in a magnetically stirred water bath at 60°C. Then, add ethylene glycol to the solution and stir until homogeneous to obtain an organic adhesion layer, wherein the content of PVA is 3.2 wt% and the content of ethylene glycol is 2 wt%.

[0117] S2. The organic adhesive layer is coated onto a glass plate and dried at 60°C for 1 hour to obtain the adhesive material;

[0118] S3. Place the glass plate on the heating table and heat it to 65°C. Then, attach the stamp with the spin-coated cell backpack to the side of the glass plate containing the adhesive material.

[0119] S4. Apply pressure of 4500.0 Pa to the stamp for 60 s to imprint the cell backpack, so that the cell backpack and the adhesive material make conformal contact.

[0120] S5. The stamp and the cell backpack are broken and separated by peeling, leaving the regular cell backpack on the adhesive material, thus completing the micro-contact transfer of the cell backpack.

[0121] Comparative Example 8

[0122] A microcontact transfer method based on a cell backpack includes the following steps:

[0123] S1. Dissolve PVA in deionized water and mix thoroughly in a magnetically stirred water bath at 60°C. Then, add ethylene glycol to the solution and stir until homogeneous to obtain an organic adhesion layer, wherein the content of PVA is 3.2 wt% and the content of ethylene glycol is 11 wt%.

[0124] S2. The organic adhesive layer is coated onto a glass plate and dried at 60°C for 1 hour to obtain the adhesive material;

[0125] S3. Place the glass plate on the heating table and heat it to 65°C. Then, attach the stamp with the spin-coated cell backpack to the side of the glass plate containing the adhesive material.

[0126] S4. Apply pressure of 4500.0 Pa to the stamp for 60 s to imprint the cell backpack, so that the cell backpack and the adhesive material make conformal contact.

[0127] S5. The stamp and the cell backpack are broken and separated by peeling, leaving the regular cell backpack on the adhesive material, thus completing the micro-contact transfer of the cell backpack.

[0128] Comparative Example 9

[0129] The difference between Comparative Example 9 and Example 4 is that only PVA is used as the organic adhesion layer in step S1;

[0130] Comparative Example 10

[0131] The difference between Comparative Example 10 and Example 4 is that ethylene glycol in step S1 is replaced with propylene glycol;

[0132] Comparative Example 11

[0133] The difference between Comparative Example 11 and Example 4 is that ethylene glycol in step S1 is replaced with butanediol;

[0134] Comparative Example 12

[0135] The difference between Comparative Example 12 and Example 4 is that ethylene glycol in step S1 is replaced with glycerol.

[0136] Transfer efficiency

[0137] Example 1 82.3％ Comparative Example 1 69.7％ Comparative Example 7 49.3％ Example 2 85.5％ Comparative Example 2 5.3％ Comparative Example 8 67.7％ Example 3 85.8％ Comparative Example 3 45.7％ Comparative Example 9 20.7％ Example 4 89.7％ Comparative Example 4 2.0％ Comparative Example 10 39.0％ Comparative Example 5 37.3％ Comparative Example 11 44.3％ Comparative Example 6 1.3％ Comparative Example 12 1.3％

[0138] The following explanation is provided in conjunction with the embodiments and accompanying drawings. Figure 7As can be seen from the different heating temperatures in Example 4 and Comparative Example 1, A represents the transfer effect of Comparative Example 1. When the transfer temperature is insufficient, only the center point of each backpack can be transferred; B represents the transfer effect of Comparative Example 2. When the transfer temperature is high, the cell backpack material of each cell backpack will melt, resulting in a patterned and uneven transfer. Figure 13 This is a graph showing the comparison of transfer efficiency of cell backpacks at different transfer temperatures.

[0139] from Figure 8 As can be seen, A represents the transfer effect of Comparative Example 3. When the applied pressure is insufficient, some cell backpacks can be transferred, while most cell backpacks can only transfer a center point or even not transfer at all; B represents the transfer effect of Comparative Example 4. When the applied pressure is too high, the cell backpack material in the center of the raised part of the cell backpack stamp will also be completely transferred, causing the entire piece to be torn off. Figure 14 A comparative graph showing the transfer efficiency of the cell transfer backpack under different applied pressures. From Figure 9 As can be seen, A represents the transfer effect of Comparative Example 5. When the transfer time is too short, only the center point of the cell backpack is transferred, while some parts are not transferred at all; B represents the transfer effect of Comparative Example 6. When the transfer time is too long, the cell backpack material in the center of the raised part of the cell backpack stamp is also completely transferred, resulting in the entire piece being torn off. Figure 15 This is a graph showing the comparison of transfer efficiency of the cell backpack at different transfer times.

[0140] from Figure 10 As can be seen from the figures, A represents the transfer effect of Comparative Example 7. When the ethylene glycol concentration decreased, some complete cell backpacks were transferred, while some parts were not transferred. B represents the transfer effect of Comparative Example 8. When the ethylene glycol concentration increased, some complete cell backpacks were transferred, while some parts were not transferred. Figure 12 This is a graph showing the comparison of transfer efficiency of cell backpacks at different concentrations of ethylene glycol.

[0141] from Figure 11 As can be seen from the comparison of transfer efficiency in Examples 9-12, Figure A shows the transfer effect when the organic adhesive coating is only PVA. In this case, only a small portion of the center point of the cell backpack can be transferred; Figure B shows the transfer effect when the organic adhesive coating is propylene glycol. In this case, a portion of the center point of the cell backpack can be transferred; Figure C shows the transfer effect when the organic adhesive coating is butanediol. In this case, almost half of the center point of the cell backpack can be transferred; Figure D shows the transfer effect when the organic adhesive coating is glycerol. The cell backpack material in the cell backpack will solidify, resulting in a patterned and uneven transfer. Figure 16 A graph showing the comparison of transfer efficiency of cell backpacks with different organic adhesive coatings.

[0142] Traditional microcontact transfer technology requires directly contacting the cell backpack stamp with a PVA-coated glass plate on a 50°C heated plate, placing a weight on it for 10 seconds, and then peeling off the cell backpack stamp; alternatively, the PVA-coated glass plate is placed in a 60°C water bath for 5 seconds before directly contacting the cell backpack stamp with it. This results in unstable microcontact transfer efficiency and higher raw material consumption for cell backpacks. This invention adds 5-9% ethylene glycol to the original organic adhesive coating, further improving the previously required water bath heating method. This allows for precise temperature and water control, and compared to adding other organic solutions, it significantly improves the current transfer efficiency, ensuring a high success rate for backpack transfer, maintaining the transfer efficiency at 80%-90%, preventing significant losses of previous backpacks, and facilitating further experiments. The emergence of this optimized microcontact transfer technology has improved work efficiency to some extent and alleviated the serious challenges.

[0143] The cell backpack-based microcontact transfer technology described above expands the application scope of microcontact transfer technology, providing more devices and materials with the possibility of using transfer technology.

[0144] The optimized method of microcontact transfer technology based on cell backpack provided by this invention has been described in detail above. Specific examples have been used to illustrate the structure and working principle of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. The above descriptions are merely preferred embodiments of this invention and are not intended to limit the invention. Furthermore, the above embodiments are merely examples for clear illustration and are not intended to limit the implementation. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention.

Claims

1. A microcontact transfer method based on a cell backpack, characterized in that, Includes the following steps: S1. An organic adhesive layer is coated onto a glass plate. The organic adhesive layer is PVA, a mixture of a hydroxyl-containing polar solvent and water, wherein the content of PVA in the mixture is 2.5-3.5 wt%, the content of the hydroxyl-containing polar solvent is 5-9 wt%, and the mixture is heated and dried to obtain an adhesive material. S2. Place the glass plate on the heating table and heat it. Then, attach the stamp with the spin-coated cell backpack to the side of the glass plate containing the adhesive material. S3. Apply a certain pressure to the stamp to imprint the cell backpack, so that the cell backpack makes conformal contact with the adhesive material; S4. The stamp and the cell backpack are broken and separated by peeling, leaving the regular cell backpack on the adhesive material, thus completing the micro-contact transfer of the cell backpack.

2. The microcontact transfer method based on a cell backpack according to claim 1, characterized in that: The hydroxyl-containing polar solvent is ethylene glycol.

3. The microcontact transfer method based on a cell backpack according to claim 1, characterized in that: The heating temperature in step S2 is 60-70℃.

4. The microcontact transfer method based on a cell backpack according to claim 1, characterized in that: In step S3, the pressure is 3200.0 Pa to 5500.0 Pa, and the pressure is applied for 50 to 70 seconds.

5. The microcontact transfer method based on a cell backpack according to claim 1, characterized in that: The stamp is a PDMS raised array mold, and the diameter, height and spacing of the cylindrical raised protrusions on the PDMS raised array mold are all 3-15μm.

6. The microcontact transfer method based on a cell backpack according to claim 5, characterized in that: The cell backpack is made of a support layer and an adhesive layer. The support layer is a polylactic acid-glycolic acid copolymer, and the adhesive layer is a mixture of polyallylamine hydrochloride and hyaluronic acid aldehyde. The adhesive layer and the support layer are spin-coated sequentially onto a micron-scale micropillar matrix structure with periodic arrangement on the surface of a PDMS protrusion array mold.

Images