Customized forming method and application of multistage T-shaped microstructure array

Abstract

The invention discloses a method for customizing and forming a multistage T-shaped microstructure array and application, and belongs to the technical field of material surface microstructure preparation. The method comprises the following steps that S1, a virtual three-dimensional micron structure model is constructed, and the three-dimensional micron structure model is subjected to 3D printing to form a solid model; wherein the solid model comprises a substrate, a plurality of bases and a plurality of filaments; the multiple bases are arranged on the substrate in an array mode, and a gap is reserved between every two adjacent bases. The multiple filaments are arranged in the same axis direction, and the multiple bases are connected to the same filament; and S2, based on the solid model, pulse laser ablation is utilized to remove the parts, located at the intervals, of all the filaments, and the multi-stage T-shaped microstructure array is obtained. According to the method, the advantage of 3D printing personalized customization is combined with the capability of achieving micron-sized fine machining through accurate positioning of pulse laser, the multi-stage T-shaped microstructure array surface is prepared, the technological process is simple, and the manufacturing efficiency is high.

Description

Technical Field

[0001] The present invention relates to the technical field of material surface microstructure preparation, and in particular to a method and application of custom-made molding of a multi-level T-shaped microstructure array. Background Art

[0002] In nature, there are concave angle structures (i.e. T-shaped microstructures) on the surfaces of animals and plants such as collembola, geckos, and pitcher plants, which can achieve superhydrophobicity. Therefore, the research on bionic T-shaped microstructures with controllable wettability came into being.

[0003] At present, the processing and preparation methods for the surface of T-shaped microstructure arrays mainly include photolithography technology, imprinting technology, plasma etching technology, etc. However, the existing technologies all have the problems of high cost and cumbersome process; photolithography technology can be seen in the existing technology 202211414647.X, which has high cost, complex process and cumbersome manufacturing process; the mold cost of imprinting technology is high and the manufacturing cycle is long, and due to the limitation of the demolding angle, it is difficult to achieve lossless demolding of the T-shaped microstructure array, which greatly limits the molding and application of the T-shaped microstructure.

[0004] In addition, the remaining material manufacturing technologies mainly include femtosecond laser technology, 3D printing technology, reactive ion etching technology, etc. Femtosecond laser technology can be seen in prior art 202311854574.0, which performs ablation on the surface of the substrate and can accurately locate and ablate to remove a certain depth and width of the substrate to form a groove and peak-valley surface structure. However, in this method, the process of forming a T-shaped microstructure array that is wide on the top and narrow on the bottom by laser ablation is extremely complicated, time-consuming, laborious, and has low processing efficiency; 3D printing technology has not yet achieved the forming of T-shaped microstructures; reactive ion etching can realize the transformation of hydrophobic surfaces to hydrophilic surfaces, but it requires high radio frequency, high gas flow and long-term etching to achieve complete wetting.

[0005] As can be seen from the above, the existing technology for preparing bionic T-shaped microstructure arrays with controllable wettability requires a long period of time, complicated processes and high costs. Summary of the invention

[0006] The present invention provides a method for custom-molding a multi-level T-shaped microstructure array and its application, aiming to solve the problem of complicated processes in the prior art, so as to shorten the manufacturing cycle and reduce costs.

[0007] A first aspect of the present invention provides a method for custom-molding a multi-level T-shaped microstructure array, comprising the following steps:

[0008] S1, constructing a virtual three-dimensional microstructure model, and 3D printing the three-dimensional microstructure model into a solid model;

[0009] The solid model comprises a base, a plurality of bases and a plurality of filaments; the plurality of bases are arranged in an array on the base, with intervals between adjacent bases; the plurality of filaments are arranged along the same axial direction, and the same filament is connected to a plurality of bases;

[0010] S2, based on the solid model, using pulsed laser ablation to remove all the portions of the filaments located in the intervals to obtain a multi-level T-shaped microstructure array.

[0011] In some embodiments of the first aspect, a plurality of the filaments are disposed on the same base, and gaps are left between the plurality of the filaments on the same base.

[0012] In some embodiments of the first aspect, in step S2, all portions of the filaments located in the intervals are removed by pulsed laser ablation. Specifically, in this step:

[0013] S20, aligning the center of the pulsed laser to the marked left edge of the substrate;

[0014] S21, moving the pulsed laser to an adjacent end-movement position along the direction of the filament, wherein the end-movement position is a point on the straight line of the filament where the interval is perpendicular to the filament;

[0015] S22, performing laser ablation in a direction perpendicular to the filaments to ablate and remove a plurality of the filaments on the same straight line;

[0016] S23, moving the pulse laser to the next stop position, and repeating steps S22 and S23 until the pulse laser ablates and removes all the portions of the filaments located in the intervals.

[0017] In some embodiments of the first aspect, in step S22, the pulse laser moves back and forth on opposite sides of the substrate.

[0018] In some embodiments of the first aspect, when the pulse laser ablates to remove the portion of the filament located in the interval, the pulse laser ablates a groove on the substrate and burns an inclined surface on the filament, wherein the groove wall is inclined toward the middle.

[0019] In some embodiments of the first aspect, the length of the ablated portion of the filament is 120 μm-240 μm.

[0020] In some embodiments of the first aspect, the pulse laser is a femtosecond pulse laser.

[0021] In some embodiments of the first aspect, after step S2, the following steps are further included:

[0022] The multi-level T-shaped microstructure array is processed by a reactive ion etching device to obtain a hydrophilic multi-level T-shaped microstructure array, wherein the reactive ion etching gas is air, the flow rate of the reactive ion etching gas is 1 sccm, the radio frequency power is 1 W, and the reaction time is less than 99 min.

[0023] In some embodiments of the first aspect, between step S1 and step S2, the following step is further included: placing the solid model in an ultrasonic cleaning instrument for ultrasonic cleaning, and then placing the solid model in an oven for drying.

[0024] The second aspect of the present invention provides the use of the multi-level T-shaped microstructure array prepared as the first aspect as a hydrophobic structure.

[0025] The third aspect of the present invention provides the use of the multi-level T-shaped microstructure array prepared in the first aspect as a hydrophilic structure.

[0026] A fourth aspect of the present invention provides a multi-level T-shaped microstructure array prepared as in the first aspect, comprising a substrate body, and a plurality of T-shaped microstructures arranged in an array on the substrate body;

[0027] The T-shaped microstructure includes a base body and a plurality of sheets; a plurality of sheets are arranged on the top of the base body, the side walls of the sheets are located outside the side walls of the base body, and gaps are left between the plurality of sheets.

[0028] In some embodiments of the fourth aspect, the plurality of sheets are arranged along a height direction of the base body.

[0029] In some embodiments of the fourth aspect, the plurality of sheets are disposed on the top end surface of the base body.

[0030] In some embodiments of the fourth aspect, the side wall surface of the sheet body is an inclined surface, and the inclined surface is inclined upward.

[0031] In some embodiments of the fourth aspect, along the direction from the substrate to the T-shaped microstructure, the lengths of the plurality of sheets gradually decrease.

[0032] In some embodiments of the fourth aspect, at least one of the sheets is disposed on the top of the base body, and at least one of the sheets is inserted into the base body.

[0033] In some embodiments of the fourth aspect, the substrate body is provided with grooves between adjacent T-shaped microstructures.

[0034] In some embodiments of the fourth aspect, the groove wall of the groove is inclined toward the middle.

[0035] In some embodiments of the fourth aspect, a plurality of holes are provided on the side wall surface of the sheet body and the surface of the groove, and the aperture of the plurality of holes is 0.001 μm-10 μm.

[0036] In some embodiments of the fourth aspect, the multi-level T-shaped microstructure array is integrally formed.

[0037] In some embodiments of the fourth aspect, the distance between adjacent T-shaped microstructures is 120 μm-240 μm;

[0038] The base body is a columnar structure or a cone structure, the side length or diameter of the base body is 400 μm-1000 μm, the height of the base is 300 μm-1000 μm, and the distance between adjacent bases is 0 μm-500 μm;

[0039] The length of the sheet is 400 μm-1000 μm;

[0040] The gap distance between adjacent sheets is 100 μm-400 μm.

[0041] It can be seen from the above technical solutions that the present invention has the following advantages:

[0042] The present embodiment provides a method for custom-molding a multi-level T-shaped microstructure array. Since a virtual three-dimensional micron structure model is constructed and the three-dimensional micron structure model is 3D printed into a physical model, the size of the multi-level T-shaped microstructure array can be customized and 3D printed, and the physical model before laser ablation is simple to make; and in the 3D printed physical model, there is a gap between adjacent bases, and the multiple filaments are arranged along the same axial direction, and multiple bases are connected to the same filament. Therefore, when it is necessary to make a T-shaped microstructure on the physical model, it is only necessary to use a pulsed laser to accurately ablate the filaments on the gap to separate different bases and the filaments thereon to form multiple T-shaped microstructures. The ablation and removal process is simple. Compared with photolithography and imprinting technology, the present embodiment does not require template assistance, has a simple process flow, high manufacturing efficiency, and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0044] Figure 1A schematic flow chart of a method for custom-molding a multi-level T-shaped microstructure array provided in an embodiment of the present invention;

[0045] Figure 2 A schematic diagram of a physical model structure provided by an embodiment of the present invention;

[0046] Figure 3 A partially enlarged schematic diagram of a solid model structure provided by an embodiment of the present invention;

[0047] Figure 4 A process schematic diagram of a method for custom-molding a multi-level T-shaped microstructure array provided in an embodiment of the present invention;

[0048] Figure 5 A schematic diagram of a cross-sectional structure of a multi-level T-shaped microstructure array provided in an embodiment of the present invention;

[0049] Figure 6 A schematic diagram of the structure of a multi-level T-shaped microstructure array provided by an embodiment of the present invention;

[0050] Figure 7 SEM photos of the solid model provided by the embodiment of the present invention;

[0051] Figure 8 A surface SEM photo of a multi-level T-shaped microstructure array provided in an embodiment of the present invention (top view);

[0052] Fig. 9 A surface SEM photograph of a multi-level T-shaped microstructure array provided in an embodiment of the present invention (front view);

[0053] Fig.10 The surface wetting state photos of the multi-level T-shaped microstructure array embodiments 1 and 2 and comparative example 1 of the present invention;

[0054] Fig.11 A photo of the holes provided for the multi-level T-shaped microstructure array of the present invention.

[0055] Reference numerals:

[0056] Ⅰ, solid model; Ⅰ1, substrate; Ⅰ2, base; Ⅰ3, filament; Ⅰ4, interval; Ⅰ5, gap; Ⅰ6, groove; Ⅰ7, pulse laser;

[0057] Ⅱ. Multi-level T-shaped microstructure array; Ⅱ1. substrate body; Ⅱ10. groove; Ⅱ2. T-shaped microstructure; Ⅱ20. base body; Ⅱ21. sheet body. DETAILED DESCRIPTION

[0058] The embodiment of the present invention provides a method and application for custom molding of a multi-level T-shaped microstructure array, which is used to solve the problem of complicated processes in the prior art, thereby shortening the manufacturing cycle and reducing the cost.

[0059] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] See also Figures 1 to 9 , a method for custom-forming a multi-level T-shaped microstructure array provided in this embodiment includes the following steps:

[0061] S1, constructing a virtual three-dimensional microstructure model, and 3D printing the three-dimensional microstructure model into a solid model I;

[0062] The entity model I includes a base I1, a plurality of bases I2 and a plurality of filaments I3; the plurality of bases I2 are arranged in an array on the base I1, and a gap I4 is left between adjacent bases I2; the plurality of filaments I3 are arranged along the same axis direction, and the same filament I3 is connected to a plurality of bases I2;

[0063] S2, based on the solid model I, the pulsed laser I7 is used to ablate and remove the parts of all filaments I3 located at the intervals I4 to obtain a multi-level T-shaped microstructure array II.

[0064] In this embodiment, a three-dimensional microstructure model is constructed according to a customized size on a three-dimensional software, and then the three-dimensional microstructure model is 3D printed into a solid model I with a customized size and containing a microstructure (see Figure 2 ), in the physical model I, multiple filaments I3 are arranged in parallel on the array-arranged bases I2, so that multiple bases I2 in each column (row) are connected by the same filament I3 to form a bridge-like structure, that is, the base I2 is the "bridge pier" and the filament I3 is the "bridge deck"; based on the physical model I, the pulsed laser I7 is used to ablate and remove the parts of all filaments I3 located at the intervals I4, that is, the filaments I3 between adjacent bases I2 on the same bridge-like structure are ablated and removed to obtain a multi-level T-shaped microstructure array II.

[0065] As can be seen from the above, the entity model I can be customized, and the size of the multi-level T-shaped microstructure array II finally prepared can be customized, and a microstructure array of multiple sizes can be prepared, and a three-dimensional micron structure model with better hydrophobicity can be obtained by adjusting the size; and the entity model I is a plurality of bridge-like structures formed by a plurality of filaments I3 and an array base I2. Therefore, the pulsed laser I7 with the ability to accurately position and realize micron-level fine processing can locate and ablate the filaments I3 between adjacent bases I2, so that a high-precision multi-level T-shaped microstructure array II surface can be prepared.

[0066] Compared with the existing technology, firstly, the manufacturing process of the solid model I before laser ablation is simple. It only needs to construct a virtual three-dimensional micron structure model through software, and then 3D print the three-dimensional micron structure model to complete the structure manufacturing before cutting based on laser ablation. There is no need to induce microstructure shrinkage and self-growth through laser heat as in the existing technology, nor is there a need to form a structure through a method of combining photolithography with etching as in the existing technology. The manufacturing process is simple and the manufacturing cycle is short. Secondly, the cutting process based on laser ablation is simple. Since the solid model I is a plurality of bridge-like structures formed by a plurality of filaments I3 and an array base I2, the cutting process of laser ablation is simple. When manufacturing the T-shaped microstructure array, it is only necessary to use a pulsed laser Ⅰ7 with micron-level fine processing capability to ablate and remove the filaments Ⅰ3 between adjacent bases Ⅰ2, and the production of the T-shaped microstructure array is completed. There is no need for a series of processes such as casting, transfer, and bonding as required in the prior art, and there is no need to set the laser control trajectory in advance as in the prior art to cut each T-shaped microstructure in a circular trajectory. The cutting process based on laser ablation is very simple. It can be seen that the physical model Ⅰ before the cutting based on laser ablation in this embodiment is simple to manufacture, and the cutting process based on laser ablation is also simple. The production of the T-shaped microstructure array does not require template assistance, the process flow is simple, and the manufacturing efficiency is high.

[0067] As an example, Figure 4 As shown, an implementable method in step S1 is further provided, and step S1 specifically includes the following steps:

[0068] S10, using software to construct a virtual three-dimensional micron structure model, that is, constructing a three-dimensional micron structure model according to the structure of the solid model I.

[0069] S11, slicing the three-dimensional microstructure model and setting 3D printing parameters.

[0070] In one embodiment, the parameters of 3D printing include: a preset printing speed of 10 mm / s-60 mm / s, a preset filling density of 80%-100%, a preset printing accuracy of 100 μm-250 μm, a preset filling pattern of concentric circles or straight lines, and a preset printing material of a high molecular polymer material.

[0071] Among them, the selection of high molecular polymer materials includes any one or more combinations of polyetheretherketone, polyetherketoneketone, acrylonitrile-butadiene-styrene (ABS), polylactic acid, high impact polystyrene (HIPS), thermoplastic polyurethane, polyamide, carbon fiber reinforced polyetheretherketone composite material (CF / PEEK), carbon fiber reinforced polylactic acid composite material (CF / PLA), and hydroxyapatite reinforced polyetheretherketone composite material (HA / PEEK).

[0072] S12, the three-dimensional microstructure model is 3D printed into a solid model I according to the set parameters (see Figure 2 ).

[0073] In one embodiment, if Figures 2 to 4 As shown, a plurality of filaments Ⅰ3 are provided on the same base Ⅰ2, and gaps Ⅰ5 are left between the plurality of filaments Ⅰ3 on the same base Ⅰ2. After the T-shaped microstructure Ⅱ2 is formed, the head of the same T-shaped microstructure Ⅱ2 will have a plurality of sheets Ⅱ21 composed of a plurality of parallel filaments Ⅰ3, which increases the surface area of ​​the subsequently manufactured T-shaped microstructure array, improves the overall structural stability, and optimizes the stress distribution; and because the solid model Ⅰ of the multi-layer structure is 3D printed, the structural preparation method of the solid model Ⅰ of the multi-layer structure is simple, and does not require complicated production processes as in the prior art.

[0074] Among them, multiple filaments I3 can be arranged along the height direction of the base body II20, that is, a multi-layer filament I3 structure is formed on the vertical cross-sectional surface of the base body II20; multiple filaments I3 can also be laid flat on the top of the base body II20, that is, multiple parallel filaments I3 are formed on the top surface of the base body II20.

[0075] Based on the above embodiments, Figures 2 to 4 As shown, the positional relationship between the multiple filaments Ⅰ3 and the base Ⅰ2 can be that the filaments Ⅰ3 are inserted in and extend out of the base Ⅰ2, or that the filaments Ⅰ3 are connected to the top surface of the base Ⅰ2. In a specific implementation, the multiple filaments Ⅰ3 are partially inserted in the base Ⅰ2, and partially connected to the top surface of the base Ⅰ2, so that the entire T-shaped microstructure array structure manufactured subsequently is more compact.

[0076] The number of filaments I3 inserted in each base I2 is 1-5; the upper and lower intervals I4 between two adjacent filaments I3 inserted in one base I2 are 100 μm-400 μm.

[0077] In one embodiment, the base Ⅰ1 of the solid model Ⅰ is one of a rectangle, a cylinder, and a prism.

[0078] Among them, the side length of the base Ⅰ1 of the rectangle is 10 mm -100 mm, and the height is 0 mm -10 mm; the diameter of the base Ⅰ1 of the cylinder is 10 mm -100 mm, and the height is 0 mm -10 mm; the upper and lower rectangular sides of the base Ⅰ1 of the prism have a length of 10 mm -100 mm, and a height of 0 mm -10 mm.

[0079] In one embodiment, the base I2 of the entity model I is a cylindrical structure or a conical structure, that is, the base I2 of the entity model I is one of a prism, a cylinder, a quadrangular pyramid, a cone, and a rectangular body, the side length or diameter of the base I2 is 400 μm-1000 μm, the height of the base I2 is 300 μm-1000 μm, and the distance between adjacent bases I2 is 0 μm-500 μm.

[0080] Among them, the upper and lower rectangular sides of the base Ⅰ2 of the prism and rectangular body are 400 μm-1000 μm long, and the height is 300 μm-1000 μm; the diameter of the base Ⅰ2 of the cylinder is 400 μm-1000 μm, and the height is 300 μm-1000 μm; the bottom side of the base Ⅰ2 of the quadrangular pyramid is 400 μm-1000 μm long, and the height is 300 μm-1000 μm; the bottom diameter of the base Ⅰ2 of the cone is 400 μm-1000 μm, and the height is 300 μm-1000 μm.

[0081] In one embodiment, the length of the filament I3 matches the side length or diameter of the substrate I1, the radial length of the filament I3 is 100 μm-1000 μm, and the filament I3 is a cylinder or a cuboid.

[0082] Among them, the diameter of the cylindrical filament Ⅰ3 is 400 μm-1000 μm, and the length is the side length of the base Ⅰ1; the short side length of the rectangular filament Ⅰ3 is 400 μm-1000 μm, the length is 10 μm-100 μm, and the height is 100 μm-1000 μm.

[0083] As an example, Figure 4 , Figure 7 , Figure 8 and Fig. 9 As shown, an implementable method in step S2 is further provided, and step S2 is specifically:

[0084] S20, based on the solid model I, align the pulse laser I7 with the substrate I1.

[0085] In one embodiment, the center of the laser spot is aligned with the left border of the solid model I.

[0086] S21, such as Figure 4 , Figure 8 and Fig. 9 As shown, along the direction of the filament Ⅰ3, the pulse laser Ⅰ7 is moved to an adjacent termination position, wherein the termination position is a point on a straight line perpendicular to the filament Ⅰ3 at interval Ⅰ4 on the filament Ⅰ3.

[0087] In one embodiment, the end movement position is a point on a straight line between the centers of two adjacent bases Ⅰ2 on the same filament Ⅰ3. For example, counting from the left boundary, on a straight line of a filament Ⅰ3, the center between the first base Ⅰ2 and the second base Ⅰ2 is the end movement position. The other end movement positions are the same and will not be elaborated here.

[0088] S22, such as Figure 4 and Figure 8 As shown, laser ablation is performed in a direction perpendicular to the filament Ⅰ3 to ablate and remove multiple filaments Ⅰ3 on the same straight line.

[0089] In specific implementation, since each base Ⅰ2 is arranged in an array and the filaments Ⅰ3 are arranged in parallel on these bases Ⅰ2, during laser ablation, it is only necessary to separate multiple filaments Ⅰ3 along a straight line, that is, just cut along a straight line, without the need to control into multiple circular trajectories. The cutting trajectory based on laser ablation and the cutting control process based on laser ablation are very simple.

[0090] In one embodiment, the pulse laser Ⅰ7 moves back and forth on the opposite sides of the substrate Ⅰ1, that is, the pulse laser Ⅰ7 performs laser ablation back and forth multiple times in a straight line perpendicular to the direction of the filament Ⅰ3, with one side of the substrate Ⅰ1 as the starting point and the end point, so that the filament Ⅰ3 interspersed between the adjacent bases Ⅰ2 in this column (row) is ablated and removed at the center, so that the multiple filaments Ⅰ3 are disconnected at the interval Ⅰ4 between the two bases Ⅰ2, so as to form multiple T-shaped microstructures Ⅱ2 at the same time, thereby avoiding processing errors when only one T-shaped microstructure Ⅱ2 is processed at a time.

[0091] In one embodiment, if Figure 4 and Figure 8As shown, in order to increase the surface area of ​​the multi-level T-shaped microstructure array II, when the pulse laser I7 ablates and removes the portion of the filament I3 located at the interval I4, the pulse laser I7 ablates a groove I6 on the substrate I1, that is, a groove I6 is formed below the ablated and removed portion of the filament I3, and an inclined surface is ablated on the filament I3, wherein the groove wall of the groove I6 is inclined toward the middle. In specific implementation, on the one hand, the preparation of the inclined surface of the head of the T-shaped microstructure II2 and the groove I6 of the substrate I1 only requires one step without separate operations, and the process is less and simple; on the other hand, the surface area of ​​the multi-level T-shaped microstructure array II prepared in the end is increased, providing more attachment sites and contact areas for forming functional functional groups and hydrophilic groups on the multi-level T-shaped microstructure array II for subsequent reactive ion etching.

[0092] Based on the above embodiments, Figure 4 and Fig. 9 As shown, groove Ⅰ6 is a V-shaped groove, and the ablated removal surface of filament Ⅰ3 forms a surface inclined upward, that is, from the cross-sectional surface, the ablated removal portion of filament Ⅰ3 and the V-shaped groove form a V-shaped structure. After the V-shaped structure is formed, the surface area of ​​the multi-level T-shaped microstructure array Ⅱ can be further increased.

[0093] In one embodiment, the depth of laser ablation from the top of the filament I3 to the bottom of the base V-groove is 100 μm-1000 μm, and the spacing of the broken filament I3 after laser ablation is 0 μm-500 μm, that is, the spacing between each two adjacent multi-level T-shaped microstructures II2 is 0 μm-500 μm. Furthermore, the length of the ablated and removed portion of the filament I3 is 120 μm-240 μm. In specific implementation, the ablated and removed position will form a spacing between adjacent T-shaped microstructures II2, and this spacing is 120 μm-240 μm. The hydrophobicity can be improved within this spacing range.

[0094] In one embodiment, the pulse laser I7 is a femtosecond pulse laser I7, which has micron-level fine processing capability, and micro-nano-scale holes are formed where the femtosecond pulse laser I7 ablates (see Fig.11 ), further increasing the surface area. These holes exist in the V-groove and on the side of the broken filament Ⅰ3. The further increased surface area provides more attachment sites and contact areas for reactive ion etching to form functional functional groups and hydrophilic groups on the surface of the three-dimensional structure model, thereby achieving better wetting effect.

[0095] The laser parameters are as follows: pulse energy density 10.35 J / cm 2The number of scans is 8-24 times, and 24 times is finally preferred. The focal length is the parameter of the field mirror, that is, the distance between the galvanometer and the workpiece surface is 300 mm, the laser wavelength is 1030 nm, the pulse width is 500 fs, the frequency is 1 kHz, and the scanning speed is 800 mm / s.

[0096] S23, such as Figure 4 As shown, the pulse laser I7 is moved to the next end position, and steps S22 and S23 are repeated until the pulse laser I7 ablates and removes all the portions of the filaments I3 located in the intervals I4.

[0097] In specific implementation, since each base Ⅰ2 is arranged in an array and the filaments Ⅰ3 are arranged in parallel on these bases Ⅰ2, during laser ablation, it is only necessary to repeat the separation of all filaments Ⅰ3 along a straight line trajectory for multiple times. The cutting trajectory based on laser ablation and the cutting control process based on laser ablation are simple.

[0098] In one embodiment, the laser spot is offset to the right for a second time by a preset distance to the next terminal movement position, the preset distance being the side length of the bottom edge of base Ⅰ2 plus the spacing between the bottom edges of adjacent bases Ⅰ2. After the second offset, the center of the laser spot reaches the middle position between the second base Ⅰ2 and the third base Ⅰ2; the distance of the third offset of the laser spot is consistent with the second time, and after the offset, it reaches the middle position between the third base Ⅰ2 and the fourth base Ⅰ2; and so on, the subsequent offset distances all repeat the second offset distance, and finally femtosecond laser ablation is completed on the three-dimensional structure model to obtain the required multi-level T-shaped microstructure array II surface.

[0099] As an example, in order to improve the surface quality and precision of the T-shaped microstructure array, between step S1 and step S2, the following steps are also included: placing the solid model I in an ultrasonic cleaning instrument for ultrasonic cleaning, and then placing the solid model I in an oven for drying.

[0100] In this embodiment, after specific implementation, the surface powder, surface residue and some surface defects in the 3D printed solid model I can be cleaned away by ultrasonic cleaning, so that the surface of the solid model I can achieve better smoothness, which is conducive to subsequent processing.

[0101] In one embodiment, the solid model I is placed in an ultrasonic cleaning instrument and ultrasonically cleaned in deionized water for 15 minutes. Subsequently, the three-dimensional structure model is placed in an oven and dried at 60-120° C. for 2 h to 12 h.

[0102] As an example, in order to transform the T-shaped microstructure array from a hydrophobic structure to a hydrophilic structure, after step S2, the following steps are also included: using a reactive ion etching device to process the multi-level T-shaped microstructure array II to obtain a hydrophilic multi-level T-shaped microstructure array II, wherein the reactive ion etching gas is air, the reactive ion etching gas flow rate is 1 sccm, the RF power is 1 W, and the reaction time is 0 min-99 min.

[0103] In this embodiment, during the specific implementation, reactive ion etching is used to etch the multi-level T-shaped microstructure array II, and the surface of the multi-level T-shaped microstructure array II changes. On the one hand, under the action of radio frequency, plasma is formed by ionizing gas in a closed chamber, and the surface of the object is bombarded at high speed, so that the hydrophilic groups can attach to the surface of the object and turn it into a hydrophilic surface, thereby achieving a wetting effect; on the other hand, the surface roughness can be further increased by reactive ion etching, so that its surface energy is increased, which is conducive to the adsorption and spreading of water molecules on the surface, thereby improving the hydrophilicity; compared with the prior art, the process of the T-shaped microstructure array provided in this embodiment from hydrophobic to hydrophilic is very short, and the effect of complete wetting can be achieved without high radio frequency and high gas flow.

[0104] In the above embodiment, a multi-level T-shaped microstructure array II is provided which can realize the transition from a hydrophobic state to a hydrophilic state and has controllable wettability. The multi-level T-shaped microstructure array II with hydrophobicity is obtained by processing through steps S1 and S2, while the multi-level T-shaped microstructure array II with hydrophilicity is obtained by processing through steps S1, S2 and reactive ion etching after step S2.

[0105] In some applications of hydrophobic structures, the hydrophobic multi-level T-shaped microstructure array II prepared by the above method can be used as the hydrophobic surface of self-cleaning windows and photovoltaic transparent shields, so that water droplets form spherical water beads on their surface. Due to the low adhesion of the surface, the water droplets will roll under the action of gravity or wind, and carry away pollutants such as dust during the rolling process, thereby achieving a self-cleaning effect; it can also be used as a drag reduction surface for ships and submarines. When an object moves in a fluid, the hydrophobic surface can reduce the contact area between the object and the fluid, effectively reducing the viscous resistance of the fluid; it can also be used as the surface of waterproof clothing and textiles. The hydrophobic surface can make water droplets form water beads on the surface of the clothing and roll down without penetrating into the inside of the fabric, thereby achieving a waterproof effect. It can also be used as the corrosion-resistant surface of the bottom of ships, steel structures of bridges, and chemical equipment. The hydrophobic surface can prevent direct contact between water and corrosive substances and the surface of the protected object. It can also be used as the antifreeze surface of outdoor equipment, power transmission lines and other devices. It is difficult for water droplets to stay and freeze on the surface, reducing the formation of ice. It can also be used as the hydrophobic surface of heat exchange equipment such as heat exchangers, radiators, and heat pipes. It can change the flow state and heat transfer mode of the fluid and increase the convective heat transfer coefficient between the fluid and the surface. It can also be used as the surface of micro-nanoscale fluid devices to regulate the flow behavior of the fluid. It can also be used as the anti-biological fouling surface of marine ships, aquaculture facilities and other devices to reduce the adsorption of biological molecules and the adhesion of biological cells.

[0106] In some applications of hydrophilic structures, the hydrophilic multi-level T-shaped microstructure array II prepared by the above method can be used as the hydrophilic microchannel of microfluidic chips and microchannel reactors, so that the fluid flows more evenly and reduces fluid retention and blockage; it can also be used as an anti-fog surface for automobile glass, eyeglass lenses and bathroom mirrors. Water vapor will form a uniform water film on the hydrophilic surface instead of condensing into water droplets to prevent fogging; it can also be used as the surface of water filtration membranes, oil-water separation membranes and hemodialysis membranes to separate liquids; it can also be used as the heat exchange surface of heat pipes and heat exchangers to enhance the heat exchange performance of workpieces.

[0107] See also Figure 5 and Figure 6 The embodiment of the present invention provides a multi-level T-shaped microstructure array II, which is prepared by the above-mentioned method for custom-molding the multi-level T-shaped microstructure array II, including:

[0108] Base body II1;

[0109] T-shaped microstructure II2, multiple T-shaped microstructure arrays are arranged on the substrate body II1, and the T-shaped microstructure II2 includes a base body II20 and multiple sheet bodies II21; multiple sheet bodies II21 are arranged on the top of the base body II20, and the side walls of the sheet bodies II21 are located outside the side walls of the base body II20, and gaps are left between the multiple sheet bodies II21.

[0110] In this embodiment, a plurality of sheets Ⅱ21 are located on the top of the base body Ⅱ20, and the side walls of the sheet body Ⅱ21 are located outside the side walls of the base body Ⅱ20 to form a T-shaped microstructure Ⅱ2; and a multilayer structure with gaps is formed between the plurality of sheets Ⅱ21, and the surface area of ​​the multilayer structure can be exposed as much as possible, thereby effectively increasing the surface area of ​​the multi-level T-shaped microstructure array Ⅱ for hydrophilic or hydrophobic applications.

[0111] In a hydrophilic application process, multiple capillary channels are formed between the multilayer structure formed by multiple sheets II 21, and the capillary action of the entire T-shaped microstructure array is strong. After water contacts the T-shaped microstructure II 2, the water will spread rapidly and evenly under the capillary action of the capillary channels, and the hydrophilic performance is good.

[0112] In a hydrophobic application process, the gaps between the multi-layer structure formed by multiple sheets II 21 will trap air to form a multi-layer air barrier. When water falls, it first contacts the air barrier, effectively increasing the contact angle and improving the hydrophobic performance.

[0113] From the above process, it can be seen that the multiple sheets Ⅱ21 of this embodiment form a multi-layer structure on the base body Ⅱ20, and gaps are formed between the multiple sheets Ⅱ21, so the surfaces of the multiple sheets Ⅱ21 can be fully exposed, effectively increasing the surface area of ​​the multi-level T-shaped microstructure array Ⅱ. Compared with the T-shaped microstructure array with only a single-layer head structure in the prior art, it has a larger surface area and better hydrophobic and hydrophilic effects.

[0114] As an example, Figure 5 and Figure 6 As shown, a feasible method of the substrate body II1 is further provided, and the substrate body II1 is one of a rectangular body, a cylinder, and a prism.

[0115] In a specific embodiment, Figure 5 and Figure 6 As shown, in order to further increase the surface area of ​​the substrate body II1, the substrate body II1 is provided with grooves II10 between adjacent T-shaped microstructures II2. In specific implementation, the presence of the grooves II10 can further increase the surface area of ​​the multi-level T-shaped microstructure array II.

[0116] In one embodiment, if Figure 5 and Figure 6 As shown, the groove wall surface of groove Ⅱ10 is inclined toward the middle. For example, groove Ⅱ10 can be a V-shaped groove, and groove Ⅱ10 can also be an arc-shaped groove Ⅱ10. In specific implementation, groove Ⅱ10 having an inclined surface inclined toward the middle has a larger surface area than ordinary regular diameter groove Ⅱ10.

[0117] As an example, Figure 5 and Figure 6As shown, an implementable method of the T-shaped microstructure II2 is further provided. The T-shaped microstructure II2 includes a base body II20 and a plurality of sheet bodies II21, at least one sheet body II21 is arranged at the top of the base body II20, and at least one sheet body II21 is inserted into the base body II20. For example, the number of sheet bodies II21 is three, two sheet bodies II21 are inserted into the base body II20, and one sheet body II21 is arranged at the top of the base body II20. When it is implemented specifically, the structure of the sheet body II21 and the base body II20 is more compact.

[0118] In one embodiment, if Figure 5 and Figure 6 As shown, multiple sheets II21 are arranged along the height direction of the base body II20, that is, a multi-layer sheet body II21 structure is formed on the vertical cross-sectional surface of the base body II20. In specific implementation, multiple sheets II21 increase the surface area of ​​the base body II20 in the height direction.

[0119] In one embodiment, multiple sheets II21 are arranged on the top end face of the base body II20, that is, multiple parallel filaments I3 are formed on the top end face of the base body II20. In specific implementation, the multiple sheets II21 arranged on the top end face can increase the surface area in the horizontal direction.

[0120] In a specific embodiment, Figure 5 and Figure 6 As shown, in order to further increase the surface area of ​​the sheet body II 21, the side wall surface of the sheet body II 21 is an inclined surface, and the inclined surface is inclined upward. In specific implementation, the side wall surface of the sheet body II 21 has an inclined surface and has a larger surface area than an ordinary vertical wall surface.

[0121] Based on the above embodiments, Figure 5 and Figure 6 As shown, in order to increase the porosity of sheet body II21, the lengths of multiple sheets II21 gradually decrease along the direction from substrate body II1 to T-shaped microstructure II2. In specific implementation, multiple sheets II21 will form a stepped structure, which helps to increase the porosity of the microstructure, thereby increasing the capillary action or increasing the volume of the air barrier.

[0122] In a specific embodiment, in order to further increase the surface area of ​​the sheet body II21, a plurality of holes are provided on the side wall surface of the sheet body II21 and the surface of the groove II10, and the pore diameter of the plurality of holes is 0.001 μm-10 μm. In specific implementation, micro-nano-level holes can be formed by femtosecond pulse laser I7, so as to further increase the surface area, and provide more attachment sites and contact areas for reactive ion etching to form functional functional groups and hydrophilic groups on the surface of the three-dimensional micron structure model, thereby achieving better wetting effect.

[0123] In one embodiment, the multi-level T-shaped microstructure array is integrally formed, that is, integrally formed by 3D printing without separate connection, thereby maintaining the integrity of the structure and improving the hydrophobic and hydrophilic performance.

[0124] In one embodiment, the distance between adjacent T-shaped microstructures Ⅱ2 is 120 μm-240 μm; the base body Ⅱ20 is a columnar structure or a cone structure, the side length or diameter of the base body Ⅱ20 is 400 μm-1000 μm, the height of the base Ⅰ2 is 300 μm-1000 μm, and the distance between adjacent bases Ⅰ2 is 0 μm-500 μm; the length of the sheet body Ⅱ21 is 400 μm-1000 μm; the gap Ⅰ5 distance between adjacent sheets Ⅱ21 is 100 μm-400 μm.

[0125] Embodiment 1

[0126] Embodiment 1 proposes a multi-level T-shaped microstructure array II, which is prepared by the above-mentioned personalized customized molding method of the multi-level T-shaped microstructure array II, and specifically includes the following steps:

[0127] A1, construct a virtual three-dimensional micron structure model, and 3D print the three-dimensional micron structure model into a solid modelⅠ.

[0128] Among them, the shape of the base Ⅰ1 of the solid model Ⅰ is a rectangular body with a size of 20 mm×20 mm×2 mm, the shape of the base Ⅰ2 is a prism, the lower bottom surface of the prism is a rectangle with a side length of 800 μm, the upper top surface is a rectangle with a side length of 400 μm and a height of 400 μm, and the spacing between the bottom edges of every two adjacent bases Ⅰ2 is 300 μm, and the shape of the filament Ⅰ3 is a cuboid; the short side of the cuboid filament Ⅰ3 is 400 μm, the length is 20 mm, and the height is 100 μm; the number of filaments Ⅰ3 interspersed in each base Ⅰ2 is 3; the upper and lower intervals Ⅰ4 of the filaments Ⅰ3 interspersed on each base Ⅰ2 are 100 μm, and the printing parameters include: printing accuracy is 100 μm, filling density is 100%, printing speed is 60 mm / s, filling pattern is concentric circles, and printing consumables are polyetheretherketone.

[0129] A2, put the solid model I into an ultrasonic cleaning instrument, and perform ultrasonic cleaning in deionized water for 15 min. Put the solid model I into an oven and dry it at 120 °C for 6 h.

[0130] A3, using femtosecond pulse laser Ⅰ7 to first locate the laser path, align the center of the laser spot with the base Ⅰ1, and the laser spot is offset to the right along the direction of the filament Ⅰ3. The starting point of the offset distance is the left boundary marked in the direction of the extended filament Ⅰ3, and the end point is the center between the first and second bases Ⅰ2 along the left boundary along the direction of the filament Ⅰ3. Then, laser ablation is performed reciprocatingly multiple times in the direction perpendicular to the filament Ⅰ3, and the filament Ⅰ3 interspersed between this row of adjacent bases Ⅰ2 is ablated and removed at the center, so that the filament Ⅰ3 is disconnected at the interval Ⅰ4 between the two bases Ⅰ2, and a V-shaped groove is formed on the surface of the model. The depth of laser ablation is 900 μm from the top of the filament Ⅰ3 to the bottom of the base V-shaped groove. After laser ablation, the spacing between the disconnected filaments Ⅰ3 is 120 μm, that is, the spacing between each two adjacent multi-level T-shaped microstructures Ⅱ2 is 120 μm. The laser spot is offset to the right a certain distance for the second time, and the distance is the length of the bottom edge of base Ⅰ2 plus the spacing between the bottom edges of adjacent bases Ⅰ2. After the second offset, the center of the laser spot reaches the middle position between the second base Ⅰ2 and the third base Ⅰ2; the distance of the laser spot offset for the third time is the same as the second time, and after the offset, it reaches the middle position between the third base Ⅰ2 and the fourth base Ⅰ2; and so on, the subsequent offset distances repeat the second offset distance, and finally femtosecond laser ablation is completed on the solid model Ⅰ, and the required multi-level T-shaped microstructure array Ⅱ surface is obtained.

[0131] Embodiment 2

[0132] Example 2 proposes a multi-level T-shaped microstructure array II, whose structure and preparation method are basically the same as those of Example 1, except that the spacing between the broken filaments I3 after laser ablation is not 120 μm, that is, the spacing between each adjacent two multi-level T-shaped microstructures II2 is not 120 μm, but the spacing between the broken filaments I3 after laser ablation is 240 μm, that is, the spacing between each adjacent two multi-level T-shaped microstructures II2 is 240 μm.

[0133] Comparative Example 1

[0134] Comparative Example 1 proposes a sample without a microstructure surface, which is prepared by a molding machine. The molding heating temperature is 380° C., the preheating time is 30 min, and polyetheretherketone is used as the material for preparing the surface without a microstructure.

[0135] The reactive ion etching process was performed on Example 1, Example 2 and Comparative Example 1. The reactive ion etching gas was air, the gas flow rate was 1 sccm, the RF power was 1 W, the reaction time was 5s, 180s, 540s, and 1080s. Static contact angles were measured for Example 1, Example 2 and Comparative Example 1. The results are shown in Table 1.

[0136] Table 1 Static contact angles of Example 1, Example 2 and Comparative Example 1 at different reactive ion etching times

[0137]

[0138] It can be seen from Table 1 that before reactive ion etching, the contact angle of the multi-level T-shaped microstructure array II of Example 1 was 130.9°, and after reactive ion etching, the multi-level T-shaped microstructure array II had been transformed into a completely wetted hydrophilic surface when the reactive ion etching time was 5s; before reactive ion etching, the contact angle of the multi-level T-shaped microstructure array II of Example 2 was 138.9°, and after reactive ion etching, the multi-level T-shaped microstructure array II had been transformed into a completely wetted hydrophilic surface when the reactive ion etching time was 5s; before reactive ion etching, the surface sample without microstructure of the comparative example had a surface contact angle of 130.9°, and after reactive ion etching, the multi-level T-shaped microstructure array II had been transformed into a completely wetted hydrophilic surface when the reactive ion etching time was 5s. The contact angle of the surface without microstructure is 95.8°. After reactive ion etching, the contact angle of the surface without microstructure is 89.0° when the reactive ion etching time is 5s, which is only 6.8° lower than before reactive ion etching. The contact angle is 35.7° when the etching time is 180s, and the contact angle is 19.9° when the etching time is 540s and 1080s. When the etching time is increased to 2160s, the contact angle of the surface without microstructure is 16.3°, which is only 3.6° lower. Although the reactive ion etching time is further increased, the hydrophilicity of the surface without microstructure is not significantly improved, and it is difficult to achieve a state of complete wetting, that is, it is difficult to completely transform into a super hydrophilic surface.

[0139] like Fig.10 As shown, Fig.10 (a) is the surface of comparative example 1 without reactive ion etching, and the static contact angle of comparative example 1 without etching is 95.8°; Fig.10 (b) is the surface of comparative example 1 after reactive ion etching (5 s), at which the static contact angle of comparative example 1 without etching is 89.0°; Fig.10 (c) is the surface of comparative example 1 after reactive ion etching (2160 s), at which the static contact angle of comparative example 1 without etching is 16.3°; Fig.10 (d) is the surface of Example 1 without reactive ion etching, and the static contact angle of Example 1 is 130.9°; Fig.10 (e) is the surface of Example 1 after reactive ion etching (5 s), at which time the static contact angle of Example 1 is 0°.

[0140] To summarize:

[0141] 1. The static contact angle of Example 2 (138.9°) is 8° higher than the static contact angle of Example 1 (130.9°). The difference between the two in their preparation is that the spacing of the broken filaments Ⅰ3 after laser ablation is different, so that the spacing between each two adjacent multi-level T-shaped microstructures Ⅱ2 is different. The laser ablation breaking spacing of Example 2 (240 μm) is twice as large as the laser ablation breaking spacing of Example 1 (120 μm). It can be seen that a moderate increase in the spacing of the T-shaped microstructure Ⅱ2 between 120 μm and 240 μm can improve the hydrophobicity.

[0142] 2. The contact angle of the multi-level T-shaped microstructure array II prepared in Example 1 and Example 2 is significantly improved compared with the surface without microstructure, and the time for converting from hydrophobicity to hydrophilicity is short, and the required RF power and gas flow rate are low. There is no need for high frequency, high flow rate, and long time to complete the conversion from hydrophobicity to hydrophilicity as in the prior art.

[0143] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0144] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

Claims

1. A method for customizing a multi-level T-shaped microstructure array, characterized in that: The following steps are involved: S1, constructing a virtual three-dimensional microstructure model, and 3D printing the three-dimensional microstructure model into a solid model; The solid model comprises a base, a plurality of bases and a plurality of filaments; the plurality of bases are arranged in an array on the base, with intervals between adjacent bases; the plurality of filaments are arranged along the same axial direction, and the same filament is connected to a plurality of bases; S2, based on the solid model, using pulsed laser ablation to remove all the portions of the filaments located in the intervals to obtain a multi-level T-shaped microstructure array.

2. The method according to claim 1, characterized in that: A plurality of the long filaments are arranged on the same base, and gaps are left between the plurality of the long filaments on the same base.

3. The method according to claim 1, characterized in that In step S2, pulse laser ablation is used to remove all the portions of the filaments located in the intervals. Specifically, in this step, the following steps are performed: S20, aligning the center of the pulse laser to the substrate; S21, moving the pulsed laser to an adjacent end-movement position along the direction of the filament, wherein the end-movement position is a point on the straight line of the filament where the interval is perpendicular to the filament; S22, performing laser ablation in a direction perpendicular to the filaments to ablate and remove a plurality of the filaments on the same straight line; S23, moving the pulse laser to the next stop position, and repeating steps S22 and S23 until the pulse laser ablates and removes all the portions of the filaments located in the intervals.

4. The method according to claim 3, characterized in that In step S22, the pulse laser moves back and forth on opposite sides of the substrate.

5. The method according to any one of claims 1, 3 and 4, characterized in that: When the pulse laser ablates and removes the portion of the filament located in the interval, the pulse laser ablates a groove on the substrate and burns an inclined surface on the filament, wherein the groove wall of the groove is inclined toward the middle.

6. The method according to claim 5, characterized in that The length of the ablated portion of the filament is 120 μm-240 μm.

7. The method according to claim 1, characterized in that The pulse laser is a femtosecond pulse laser.

8. The method according to any one of claims 1 to 7, characterized in that: After step S2, the method further includes the following steps: The multi-level T-shaped microstructure array is processed by a reactive ion etching device to obtain a hydrophilic multi-level T-shaped microstructure array, wherein the reactive ion etching gas is air, the flow rate of the reactive ion etching gas is 1 sccm, the radio frequency power is 1 W, and the reaction time is less than 99 min.

9. An application of a hydrophobic structure, using a multi-level T-shaped microstructure array prepared by the method according to any one of claims 1 to 7.

10. An application of a hydrophilic structure, using the multi-level T-shaped microstructure array prepared by the method of claim 8.

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