A liquid film transfer method for surface microstructure

Abstract

The present invention discloses a liquid film transfer method for a surface microstructure, belonging to the technical field of functional surface preparation, and the method of the present invention comprises the following steps: preparing a microstructure surface; preparing a liquid film with fine substances attached; contacting the fine substances attached to the liquid film with the microstructure surface; vibrating the liquid film to transfer the fine substances to the microstructure surface; and processing the microstructure surface with the fine substances attached. The fine substances corresponding to the concave or convex positions on the microstructure surface are transferred unstably when the liquid film is vibrated, thereby realizing the transfer of the fine substances on the liquid film to the microstructure surface.

Description

Technical Field

[0001] The invention relates to the technical field of functional surface preparation, and in particular to a method for realizing surface microstructure transfer through a liquid film. Background Art

[0002] Appropriate microstructures on functional surfaces can play specific roles in light, sound, electricity, magnetism, heat and matter, and have attracted extensive attention from academia and engineering. On some functional surfaces, such as superoleophobic surfaces, not only are microstructures required, but they are also required to have appropriate orientations. For example, the large head of the mushroom-shaped microstructure on the superoleophobic surface needs to face outward from the surface. Therefore, the orientation control of surface microstructures has received extensive attention in recent years.

[0003] Generally speaking, surface microstructures can be achieved through mechanical processing, chemical treatment, material deposition and other means, but these methods have certain limitations in controlling the orientation of microstructures. Mechanical processing can only obtain simple microstructure surfaces such as protrusions, grooves, and micropores; the surface microstructure obtained by chemical treatment is a random microstructure with poor orientation; the microstructure formed by material deposition is related to the deposition process. The realization of oriented microstructures usually requires a suitable atmosphere (high vacuum), suitable materials and suitable process conditions, and the controllability is poor. Generally, at the liquid-gas interface, fine matter will produce a specific orientation and present a specific state due to the effects of surface energy and surface tension. By utilizing this orientation arrangement characteristic of fine matter on the liquid-gas interface, with the help of the liquid film spread on the surface as the intermediate transfer medium of the fine matter, it is expected that the fine matter can be transferred to a specific target surface, and the preparation of surface oriented microstructures can be achieved. However, the stability of the attachment state of fine matter on the liquid film is an important factor restricting the transfer process of fine matter attached to the liquid film. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a liquid film transfer method for a surface microstructure, which achieves the transfer of fine substances on the liquid film to the microstructure surface by causing the fine substances corresponding to the concave or convex positions on the microstructure surface to be unstable and transferred when the liquid film is vibrated.

[0005] The present invention achieves the above technical objectives through the following technical means.

[0006] A liquid film transfer method for a surface microstructure comprises the following steps: preparing a microstructure surface; preparing a liquid film with fine substances attached; contacting the fine substances attached to the liquid film with the microstructure surface; vibrating the liquid film to transfer the fine substances to the microstructure surface; and processing the microstructure surface with the fine substances attached.

[0007] In the above solution, the microstructure surface is micro-protrusions / or micro-grooves / or micro-pores.

[0008] In the above scheme, the size of the fine matter is between 1 μm and 200 μm.

[0009] In the above scheme, the specific steps of preparing the liquid film with attached fine substances include: dripping liquid droplets on the surface of the flat plate to form a liquid film on the surface of the flat plate, so that the liquid film is in contact with the fine substances; or, preparing a solution that can react with a specific gas to generate a solid substance, spreading the solution on a flat plate, and placing the flat plate with the solution in an environment with a specific gas so that the solution reacts on the surface to generate fine substances.

[0010] In the above scheme, a layer of polymer film is deposited on the surface of the fine material by vapor deposition or liquid deposition to achieve hydrophobic modification of the surface of the fine material.

[0011] In the above scheme, the specific steps of transferring fine matter from the vibrating liquid film to the microstructure surface include: placing the microstructure surface horizontally, generating vibration by vertically reciprocatingly moving the liquid film, so that the fine matter attached to the liquid film is separated from the liquid film surface under the acceleration of the vibration, and is transferred to the concave part of the microstructure surface.

[0012] In the above scheme, the reciprocating movement frequency is greater than 3 Hz.

[0013] The above scheme is characterized in that the surface of the microstructure with fine substances attached thereto is treated by raising the surface temperature to 200 to 500° C. and keeping the temperature for 10 minutes to 2 hours.

[0014] In the above scheme, the microstructure surface is subjected to plasma activation treatment before the micro-substance is transferred, so as to improve the adhesion of the micro-substance on the micro-structure surface.

[0015] In the above scheme, a LiOH solution is used to prepare the liquid film, and the microstructure surface is a silicon wafer with grooves and protrusions.

[0016] The present invention has the following technical advantages:

[0017] The transfer of fine matter to the surface of the microstructure can be achieved through liquid film transfer, and the orientation effect of the liquid-gas interface on the fine matter can be utilized to achieve the oriented arrangement of the microstructure.

[0018] During the transfer process, the unstable transfer of fine matter on the liquid film occurs in the microstructure surface area. The fine matter in the area without microstructure on the surface is stable and non-adhesive, which can realize the selective transfer of fine matter attached to the liquid film to the local area.

[0019] The preparation of oriented microstructured surfaces can be achieved in an atmospheric atmosphere, with few requirements on preparation conditions.

[0020] Liquid film transfer can achieve instant transfer of large-area fine substances with high transfer efficiency and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A flow chart of a liquid film transfer method for a surface microstructure according to the present invention;

[0022] Figure 2 Schematic diagram of the generation of liquid film attached with fine matter and its contact with the microstructure surface;

[0023] Figure 3 It is a schematic diagram of the macroscopic morphology of the liquid film with attached fine matter;

[0024] Figure 4 Schematic diagram of the process of transferring fine matter attached to the microstructure surface by liquid film induced by vibration;

[0025] Figure 5 Scanning electron microscope images of the microstructure surface before and after liquid film transfer.

[0026] Reference numerals:

[0027] 1-carrying plate, 2-fine substance, 3-plate, 4-liquid film, 5-fine substance attached to the liquid film, 6-microstructure surface, 7-fine substance transferred to the depression of the microstructure surface, 8-microstructure surface with fine substance transferred from the depression, 9-fine substance transferred to the convex part of the microstructure surface, 10-microstructure surface after multiple transfers, 11-laser processed microstructure surface, 12-laser processed microstructure surface depression, 13-flower-like microstructure with liquid film transferred to the laser processed microstructure surface depression. DETAILED DESCRIPTION

[0028] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0029] Combine the following Figure 1-Figure 5 The implementation details and working conditions of the specific process proposed by the present invention are described.

[0030] Combined with Figure 1 As shown, a liquid film transfer method for surface microstructure includes five steps: preparing a surface with a microstructure; preparing a liquid film with fine substances attached; contacting the fine substances attached to the liquid film with the microstructure surface; transferring the fine substances on the liquid film to the microstructure surface by vibrating the liquid film to realize the preparation of an oriented microstructure; and post-processing the surface.

[0031] First, a microstructure surface needs to be prepared by a certain method. The preparation method of the microstructure surface 6 can be prepared by a traditional micromachining method such as a laser direct writing method and a photolithography method. The prepared microstructure can be in the form of microprotrusions, microgrooves or micropores. It is required that the width of the prepared microgrooves, the diameter of the micropores or the distance between adjacent microprotrusions be greater than the width or diameter of the fine material to be transferred, so as to realize the mechanical effect between the surface microstructure and the fine material to be transferred, thereby promoting the instability of the liquid film attached microstructure. In order to improve the adhesion of the fine material 2 on the microstructure surface, the microstructure surface 6 can be subjected to plasma activation treatment before the fine material is transferred.

[0032] The second step is to prepare the liquid film to which the fine matter is attached. There are two methods for preparation. The process of the first method is shown in the attached Figure 2 First, prepare a carrier plate 1, spread the pre-prepared fine material 2 with a size between 1μm and 200μm on the carrier plate 1, then drop liquid drops such as water droplets or oil droplets onto the plate 3, and then make the formed liquid film 4 contact with the fine material 2 laid on the carrier plate 1, so as to form a liquid film 4 with the fine material 5 attached.

[0033] The solution is spread on the flat plate 3, and the liquid film carrier plate with the solution liquid film 4 is sent into an environment with a reaction gas to react on the surface of the liquid film 4 to generate fine substances, thereby forming a liquid film 4 with fine substances 5 attached. The flat plate 3 needs to be made of a material with a large surface energy to facilitate the liquid to spread on the flat plate 3 to form a liquid film 4 with a large area. When spreading the liquid film, the liquid film can be spread by external force such as rotating the liquid film carrier plate or blowing air on the liquid film or driving the liquid film with a solid. The macroscopic morphology of the liquid film with fine substances attached is as follows: Figure 3 In the process of preparing the liquid film 4 to which the fine substances 5 are attached, in order to achieve the orientation arrangement of the fine substances on the liquid film, a polymer film (such as vapor-deposited perfluorosilane) can be deposited on the surface of the fine substances 2 by vapor deposition or liquid deposition to achieve hydrophobic modification of the surface of the fine substances.

[0034] The third step is to bring the fine matter attached to the liquid film into contact with the microstructure surface. Figure 2 The target microstructure surface 6 is placed horizontally, the liquid film 4 of the flat plate 3 is facing downward and the surface is kept horizontal, the flat plate 3 is moved so that the fine matter 5 attached to the liquid film 4 contacts the microstructure surface 6, and a gap block is placed between the flat plate 3 and the microstructure surface 6 to maintain the gap between the two surfaces.

[0035] The fourth step is to transfer the fine matter on the liquid film to the microstructure surface by vibrating the liquid film. The target microstructure surface 4 is placed horizontally and vibrated by vertical reciprocating movement. The reciprocating movement frequency is greater than 3Hz, so that the fine matter 5 attached to the liquid film 4 is separated from the surface of the liquid film 4 under the acceleration of the vibration and transferred to the concave part of the microstructure surface, becoming attached Figure 4 As shown in the figure, the microstructure surface 6 is transferred to the concave part of the microstructure surface, and the original microstructure surface 6 becomes the microstructure surface 8 with the transferred microstructure in the concave part. After multiple liquid film vibration transfers, the obtained microstructure surface has a specific microstructure, that is, the microstructure composed of the original microstructure and the transferred microstructure. These microstructures can promote the subsequent transfer process, such as the attached Figure 4 As shown, the fine substance 7 transferred to the concave part of the microstructure surface lifts up the fine substance 5 on the liquid film 4. After vibration transfer, the fine substance 5 will be transferred to the convex position on the original microstructure surface 6, and become the fine substance 9 transferred to the convex part of the microstructure surface. After multiple transfers, the microstructure surface 10 has fine substances transferred at both the concave position and the convex position.

[0036] The fifth step is surface post-treatment. Surface post-treatment is to improve the bonding performance between fine matter and microstructure surface by heating the surface. Generally, the surface temperature is raised to 200-500 degrees Celsius and kept for 10 minutes to 2 hours.

[0037] Example: Using LiOH solution to prepare a liquid film with fine material attached, the microstructure surface 6 is a silicon wafer processed by laser

[0038] See attached Figure 5 , a laser direct writing method is used to prepare a tic-tac-toe groove structure on the surface of a silicon wafer to form a laser processed microstructure surface 11, and the width of the concave portion 12 of the laser processed microstructure surface is about 50μm, and the surface is silanized to improve the surface adhesion to fine substances. The prepared laser processed microstructure surface 11 is placed horizontally, and a small amount of broken silicon wafers are laid on the laser processed microstructure surface 11 as gap blocks. A small amount of LiOH solution is poured onto a smooth silicon wafer, and the LiOH solution is spread into a thin liquid film by blowing air, and carbon dioxide gas is blown to the liquid film to react on the surface of the liquid film to generate fine substances. After the surface of the liquid film turns white, the liquid film is reversed downward to make it contact with the laser processed microstructure surface 11, and the smooth silicon wafer is contacted and fixed with the gap block of broken silicon wafers preset on the laser processed microstructure surface 11. The laser processed microstructure surface 11 is manually shaken to vibrate the fine substances and liquid film in contact with it, and the fine substances are transferred to the concave portion 12 of the laser processed microstructure surface. The flower-like microstructures 13 of the liquid film transferred to the concave part of the laser-processed microstructure surface are shown in the attached SEM picture. Figure 5As shown, the liquid film is transferred to the flower-like microstructure 13 in the concave part of the laser processed microstructure surface. The upper end of the flower-like microstructure is larger, that is, it maintains good orientation. The flower-like microstructure is enriched in the concave part 12 of the laser processed microstructure surface, that is, the liquid film transfer of the surface microstructure is achieved.

[0039] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0040] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A liquid film transfer method for surface microstructure, characterized in that: The method comprises the following steps: preparing a microstructure surface; preparing a liquid film to which fine substances are attached; contacting the fine substances attached to the liquid film with the microstructure surface; and vibrating the liquid film to transfer the fine substances to the microstructure surface. The surface of a microstructure with fine matter attached thereto is treated; wherein the specific steps of preparing a liquid film with fine matter attached thereto include: dripping liquid droplets onto the surface of a flat plate to form a liquid film on the surface of the flat plate, so that the liquid film contacts the fine matter; or, preparing a solution that can react with a specific gas to generate a solid substance, spreading the solution on a flat plate, and placing the flat plate with the solution spread thereon into an environment with a specific gas so that fine matter is generated by reaction on the surface of the solution; the specific steps of vibrating the liquid film to transfer the fine matter to the surface of the microstructure include: placing the surface of the microstructure horizontally, and generating vibration by vertically reciprocatingly moving the liquid film, so that the fine matter attached to the liquid film is separated from the surface of the liquid film under the acceleration of the vibration, thereby achieving transfer to a concave portion of the microstructure surface.

2. The liquid film transfer method of surface microstructure according to claim 1, characterized in that: The microstructure surface is micro-protrusions / micro-grooves / or micro-pores.

3. The liquid film transfer method of surface microstructure according to claim 1, characterized in that: The size of the fine matter is between 1 μm and 200 μm.

4. The liquid film transfer method of surface microstructure according to claim 1, characterized in that: A layer of polymer film is deposited on the surface of the fine material by vapor deposition or liquid deposition to achieve hydrophobic modification of the surface of the fine material.

5. The liquid film transfer method of surface microstructure according to claim 1, characterized in that: The reciprocating frequency is greater than 3 Hz.

6. The liquid film transfer method of surface microstructure according to claim 1, characterized in that: The treatment method for the microstructure surface with fine substances attached thereto is: raising the surface temperature to 200 to 500° C. and keeping the temperature for 10 minutes to 2 hours.

7. The liquid film transfer method of surface microstructure according to claim 1, characterized in that: Plasma activation treatment of the microstructure surface before the transfer of the micro-substance can improve the adhesion of the micro-substance on the microstructure surface.

8. The liquid film transfer method of surface microstructure according to claim 1, characterized in that: LiOH solution is used to prepare the liquid film, and the microstructure surface is a silicon wafer with grooves and protrusions.

Images