A method for custom molding of multi-level T-shaped microstructure arrays and its application

Abstract

This invention discloses a method and application for custom molding of multi-level T-shaped microstructure arrays, applicable to the field of microstructure fabrication technology for material surfaces. The method includes the following steps: S1, constructing a virtual three-dimensional microstructure model and 3D printing the model into a solid model; wherein the solid model includes a substrate, multiple bases, and multiple filaments; the multiple bases are arranged in an array on the substrate, with gaps between adjacent bases; the multiple filaments are arranged along the same axis, with multiple bases connected to the same filament; S2, based on the solid model, using pulsed laser ablation to remove the portions of all filaments located in the gaps, obtaining a multi-level T-shaped microstructure array. This method combines the advantages of personalized 3D printing with the precise positioning and micrometer-level fine processing capabilities of pulsed lasers to fabricate a multi-level T-shaped microstructure array surface, with a simple process and high manufacturing efficiency.

Description

Technical Field

[0001] This invention relates to the field of material surface microstructure preparation technology, and in particular to a method and application for custom molding of multi-level T-shaped microstructure arrays. Background Technology

[0002] In nature, plants and animals such as springtails, geckos, and pitcher plants have concave structures (i.e., T-shaped microstructures) on their surfaces, which enable them to achieve superhydrophobic properties. Therefore, research on biomimetic T-shaped microstructures with controllable wettability has emerged.

[0003] Currently, the main methods for fabricating T-shaped microstructure arrays include photolithography, imprinting, and plasma etching. However, all existing technologies suffer from high costs and complex processes. Photolithography, as seen in existing technology 202211414647.X, is costly, complex, and cumbersome in its manufacturing process. Imprinting technology has high mold costs and long manufacturing cycles. Moreover, due to the limitation of the demolding angle, it is difficult to achieve non-destructive demolding of T-shaped microstructure arrays, which greatly limits the molding and application of T-shaped microstructures.

[0004] In addition, other material manufacturing technologies mainly include femtosecond laser technology, 3D printing technology, and reactive ion etching technology. Femtosecond laser technology can be found in existing technology 202311854574.0. It ablates the surface of the substrate and can precisely locate and ablate to remove the substrate of a certain depth and width, forming groove and peak-valley surface structures. However, in this method, the process of forming a T-shaped microstructure array that is wider at the top and narrower at the bottom through laser ablation is extremely complex, time-consuming, labor-intensive, and has low processing efficiency. 3D printing technology has not yet been able to achieve the forming of T-shaped microstructures. Reactive ion etching can realize the transformation of hydrophobic surfaces into hydrophilic surfaces, but it requires high radio frequency, high gas flow rate, and long etching time to achieve a complete wetting effect.

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

[0006] This invention provides a method and application for custom molding of multi-level T-shaped microstructure arrays, aiming to solve the problem of cumbersome processes in existing technologies, so as to shorten the manufacturing cycle and reduce costs.

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

[0008] S1. Construct a virtual three-dimensional micron structure model and 3D print the three-dimensional micron structure model into a solid model;

[0009] The solid model includes a base, multiple bases, and multiple filaments; the multiple bases are arranged in an array on the base, with gaps between adjacent bases; the multiple filaments are all arranged along the same axial direction, and multiple bases are connected to the same filament.

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

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

[0012] In some embodiments of the first aspect, in step S2, all portions of the filaments located at the intervals are ablated using a pulsed laser. This step specifically involves:

[0013] S20, Align the center of the pulsed laser with the marked left boundary of the substrate;

[0014] S21, along the direction of the filament, the pulsed laser is moved to an adjacent termination point, wherein the termination point is a point on the filament on a straight line perpendicular to the filament;

[0015] S22, laser ablation is performed along the direction perpendicular to the filament to ablate and remove multiple filaments on the same straight line;

[0016] S23, move the pulsed laser to the next termination point, and repeat steps S22 and S23 until the pulsed laser ablates and removes all portions of the filaments located in the interval.

[0017] In some embodiments of the first aspect, in step S22, the pulsed laser reciprocates between opposite sides of the substrate.

[0018] In some embodiments of the first aspect, when the pulsed laser ablates away the portion of the filament located at the interval, the pulsed laser ablates a groove on the substrate and burns an inclined surface on the filament, wherein the groove wall is inclined toward the center.

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

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

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

[0022] The multi-level T-shaped microstructure array was processed using a reactive ion etching (RIE) device to obtain a hydrophilic multi-level T-shaped microstructure array. The gas used for RIE was air, the flow rate of the gas was 1 sccm, the radio frequency power was 1 W, and the reaction time was 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 into an ultrasonic cleaning instrument for ultrasonic cleaning, and then placing the solid model into an oven for drying.

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

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

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

[0027] The T-shaped microstructure includes a base and multiple sheets; the top of the base is provided with multiple sheets, the sidewalls of the sheets are located outside the sidewalls of the base, and gaps are left between the multiple sheets.

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

[0029] In some embodiments of the fourth aspect, multiple pieces are disposed on the top end face of the base body.

[0030] In some embodiments of the fourth aspect, the sidewall of the sheet is an inclined surface, and the inclined surface is tilted upwards.

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

[0032] In some embodiments of the fourth aspect, at least one of the said sheet bodies is disposed at the top of the base body, and at least one of the said sheet bodies 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 is inclined towards the center.

[0035] In some embodiments of the fourth aspect, the sidewall of the sheet and the surface of the groove are provided with a plurality of holes, the diameter of the plurality of holes being 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 or conical 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 base bodies is 0 μm - 500 μm.

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

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

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

[0042] This embodiment provides a method for custom molding of multi-level T-shaped microstructure arrays. Because a virtual three-dimensional microstructure model is constructed and then 3D printed into a physical model, the size of the multi-level T-shaped microstructure array can be customized and 3D printed. The physical model before laser ablation is simple to fabricate. Furthermore, in the 3D printed physical model, there are gaps between adjacent bases, and multiple filaments are arranged along the same axis. Multiple bases are connected to the same filament. Therefore, when fabricating T-shaped microstructures on the physical model, only precise pulsed laser ablation of the filaments at the gaps is needed to separate different bases and their filaments, forming multiple T-shaped microstructures. The ablation process is simple. Compared to photolithography and imprinting technologies, this embodiment requires no template assistance, has a simple process flow, high manufacturing efficiency, and reduces manufacturing costs. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

[0045] Figure 2 This is a schematic diagram of the solid model structure provided in an embodiment of the present invention;

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

[0047] Figure 4 A 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 This is 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 This is a schematic diagram of a multi-level T-shaped microstructure array provided in an embodiment of the present invention;

[0050] Figure 7 SEM images of the solid model provided in the embodiments of the present invention;

[0051] Figure 8 SEM image (top view) of the surface of a multi-level T-shaped microstructure array provided for an embodiment of the present invention.

[0052] Figure 9 SEM image (front view) of the surface of a multi-level T-shaped microstructure array provided for an embodiment of the present invention.

[0053] Figure 10 These are photographs of the surface wetting state of Embodiment 1, Embodiment 2 and Comparative Example 1 of the multi-level T-shaped microstructure array of the present invention;

[0054] Figure 11 A photograph of the holes provided for the multi-level T-shaped microstructure array of this invention.

[0055] Figure label:

[0056] I. Solid model; I1. Base; I2. Base; I3. Filament; I4. Spacing; I5. Gap; I6. Groove; I7. Pulsed laser;

[0057] II. Multi-level T-shaped microstructure array; II1. Substrate; II10. Groove; II2. T-shaped microstructure; II20. Base; II21. Sheet. Detailed Implementation

[0058] This invention provides a method and application for custom molding of multi-level T-shaped microstructure arrays, which solves the problem of cumbersome processes in existing technologies, thereby shortening the manufacturing cycle and reducing high costs.

[0059] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0060] Please see Figures 1 to 9 This embodiment provides a method for custom molding of multi-level T-shaped microstructure arrays, including the following steps:

[0061] S1, construct a virtual three-dimensional micron structure model, and 3D print the three-dimensional micron structure model into solid model I;

[0062] Among them, the solid model I includes a base I1, multiple bases I2 and multiple filaments I3; multiple bases I2 are arranged in an array on the base I1, with a gap I4 between adjacent bases I2; multiple filaments I3 are arranged along the same axis, and multiple bases I2 are connected to the same filament I3.

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

[0064] In this embodiment, a three-dimensional micron structure model is constructed on three-dimensional software according to a customized size, and then the three-dimensional micron structure model is 3D printed into a customized size solid model I containing micron structures (see Figure 2 In the solid model I, multiple filaments I3 are arranged in parallel on the arrayed 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 bases I2 are "bridge piers" and the filaments I3 are "bridge decks". Based on the solid model I, the portions of all filaments I3 located at intervals I4 are ablated by pulsed laser I7, that is, the filaments I3 between adjacent bases I2 on the same bridge-like structure are ablated to obtain a multi-level T-shaped microstructure array II.

[0065] As can be seen from the above, the physical model I can be customized, and the final multi-level T-shaped microstructure array II can be customized in size. Multi-sized microstructure arrays can be prepared, and better hydrophobic three-dimensional microstructure models can be obtained by controlling the size. Furthermore, the physical model I is composed of multiple bridge-like structures formed by multiple filaments I3 and array bases I2. Therefore, by using pulsed laser I7 with precise positioning to achieve micron-level fine processing, the filaments I3 between adjacent bases I2 can be ablated and removed, thus producing a high-precision multi-level T-shaped microstructure array II surface.

[0066] Compared to existing technologies, firstly, the fabrication process of the physical model I before laser ablation is simple. It only requires constructing a virtual three-dimensional microstructure model using software, and then 3D printing the three-dimensional microstructure model to complete the fabrication of the structure before laser ablation-based cutting. This eliminates the need for laser-induced microstructure shrinkage and self-growth as in existing technologies, and also eliminates the need for photolithography combined with etching to form the structure. The fabrication process is simple and has a short production cycle. Secondly, the cutting process based on laser ablation is simple. Since physical model I consists of multiple bridge-like structures formed by multiple filaments I3 and array base I2, the cutting process during laser ablation is straightforward. In this embodiment, the fabrication of the T-shaped microstructure array can be completed simply by using a pulsed laser I7 with micron-level precision processing capabilities to ablate and remove the filaments I3 between adjacent bases I2. This eliminates the need for a series of processes such as casting, transfer, and bonding required by existing technologies, as well as the need to pre-set the laser control trajectory to cut each T-shaped microstructure in a circular path, as is the case with existing technologies. The laser ablation-based cutting process is very simple. Therefore, it can be seen that the solid model I before laser ablation-based cutting is simple to create, the laser ablation-based cutting process is also simple, and the fabrication of the T-shaped microstructure array does not require template assistance, has a simple process flow, and high manufacturing efficiency.

[0067] As an example, such as Figure 4 As shown, a feasible method for step S1 is further provided. Step S1 specifically includes the following steps:

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

[0069] S11 slices the three-dimensional micron structure model and sets the parameters for 3D printing.

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

[0071] The selection of 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 (CF / PEEK), carbon fiber reinforced polylactic acid composite (CF / PLA), and hydroxyapatite reinforced polyetheretherketone composite (HA / PEEK).

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

[0073] In one embodiment, such as Figures 2 to 4 As shown, multiple filaments I3 are provided on the same base I2, and gaps I5 are left between the multiple 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 multiple sheets II21 composed of multiple 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. Furthermore, since the solid model I of this 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 the complex process of existing technology.

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

[0075] Based on the above embodiments, such as 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 into and extend out of the base I2, or that the filaments I3 are connected to the top surface of the base I2. In specific implementation, the multiple filaments I3 are partially inserted into the base I2 and partially connected to the top surface of the base I2, making the entire T-shaped microstructure array structure made thereafter more compact.

[0076] The number of filaments I3 inserted in each base I2 is 1-5; the vertical spacing I4 between any two adjacent filaments I3 on ​​a base I2 is 100 μm-400 μm.

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

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

[0079] In one embodiment, the base I2 of the solid model I is a columnar structure or a conical structure, that is, the base I2 of the solid model I is one of a frustum, cylinder, square pyramid, cone, or rectangle. 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 top and bottom rectangular sides of the frustum and rectangular base I2 are 400 μm-1000 μm in length and 300 μm-1000 μm in height; the diameter of the cylindrical base I2 is 400 μm-1000 μm and the height is 300 μm-1000 μm; the bottom side of the square pyramid base I2 is 400 μm-1000 μm in length and 300 μm-1000 μm in height; and the bottom diameter of the cone base I2 is 400 μm-1000 μm and the height is 300 μm-1000 μm.

[0081] In one embodiment, the length of filament I3 matches the side length or diameter of substrate I1, the radial length of filament I3 is 100 μm-1000 μm, and filament I3 is either 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 same as the side length of the base I1; the short side length of the cuboid filament I3 is 400 μm-1000 μm, the length is the same as the side length of the base I1 (10 μm-100 μm), and the height is 100 μm-1000 μm.

[0083] As an example, such as Figure 4 , Figure 7 , Figure 8 and Figure 9 As shown, a possible implementation method for step S2 is further provided. Step S2 is specifically as follows:

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

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

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

[0087] In one embodiment, the point where the movement ends is a point on the straight line between the center of two adjacent bases I2 on the same filament I3. For example, starting from the left boundary, the center between the first base I2 and the second base I2 on a straight line of filament I3 is the point where the movement ends. The other points where the movement ends are similar, and will not be described in detail here.

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

[0089] In practice, since each base I2 is arranged in an array and the filaments I3 are arranged in parallel on these bases I2, during laser ablation, the separation of multiple filaments I3 can be completed simply by following a straight trajectory, that is, by cutting along a straight line. There is no need to control multiple circular trajectories. The cutting trajectory based on laser ablation and the cutting control process based on laser ablation are both very simple.

[0090] In one embodiment, the pulsed laser I7 moves back and forth on opposite sides of the substrate I1. That is, the pulsed laser I7 performs multiple laser ablations on a straight line perpendicular to the direction of the filament I3, with one side of the substrate I1 as the starting point and the ending point. This ablates and removes the filaments I3 that intersect between adjacent bases I2 in this column (row) at the center, so that multiple filaments I3 are broken at the interval I4 between the two bases I2, so as to simultaneously form multiple T-shaped microstructures II2, avoiding the processing error when only one T-shaped microstructure II2 is processed at a time.

[0091] In one embodiment, such as Figure 4 and Figure 8As shown, in order to increase the surface area of ​​the multi-level T-shaped microstructure array II, when the pulsed laser I7 ablates and removes the portion of the filament I3 located at interval I4, the pulsed laser I7 ablates a groove I6 on the substrate I1. That is, a groove I6 is formed below the ablation and removal portion of the filament I3, and an inclined surface is ablated on the filament I3. The groove wall of the groove I6 is inclined towards the middle. In specific implementation, on the one hand, the fabrication of the inclined surface with the head of the T-shaped microstructure II2 and the groove I6 of the substrate I1 can be completed in one step without separate operations, making the process simple and less complicated. On the other hand, the surface area of ​​the multi-level T-shaped microstructure array II is increased, providing more attachment sites and contact areas for the formation of functional groups and hydrophilic groups for subsequent reactive ion etching on the multi-level T-shaped microstructure array II.

[0092] Based on the above embodiments, such as Figure 4 and Figure 9 As shown, groove I6 is a V-shaped groove, and the ablation removal surface of filament I3 forms an upwardly inclined surface. That is, from the cross-section, the ablation removal part of filament I3 and the V-shaped groove form a V-shaped structure. After forming the V-shaped structure, the surface area of ​​the multi-level T-shaped microstructure array II can be further increased.

[0093] In one embodiment, the laser ablation depth is 100 μm-1000 μm from the top of filament I3 to the bottom of the V-groove of the base. The spacing between the broken filaments 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 part of filament I3 that is ablated and removed is 120 μm-240 μm. In specific implementation, the ablation and removal position will form the spacing between adjacent T-shaped microstructures II2, which is 120 μm-240 μm. Within this spacing range, hydrophobicity can be improved.

[0094] In one embodiment, the pulsed laser I7 is a femtosecond pulsed laser I7, which possesses micron-level precision processing capabilities, and the areas ablated by the femtosecond pulsed laser I7 will form micro- and nano-scale pores (see...). Figure 11 The increased surface area, with pores existing in the V-groove and on the side of the broken filament I3, provides more attachment sites and contact area for reactive ion etching to form functional groups and hydrophilic groups on the surface of the three-dimensional structural model, thus achieving better wetting effect.

[0095] The laser parameters are as follows: pulse energy density 10.35 J / cm². 2The number of scans is 8-24, with 24 being the optimal number. The focal length is a parameter of the field lens, i.e., 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, as Figure 4 As shown, the pulsed laser I7 is moved to the next termination point, and steps S22 and S23 are repeated until the pulsed laser I7 ablates and removes all the portions of the filaments I3 located in interval I4.

[0097] In practice, since each base I2 is arranged in an array and the filaments I3 are arranged in parallel on these bases I2, during laser ablation, the separation of all filaments I3 can be completed by repeating the process multiple times along a straight trajectory. 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 a preset distance a second time to the next termination point. The preset distance is the side length of the bottom edge of base I2 plus the distance between the bottom edges of adjacent base I2. After the second offset, the center of the laser spot reaches the midpoint between the second base I2 and the third base I2. The laser spot is offset by the same distance as the second offset, and after the offset, it reaches the midpoint between the third base I2 and the fourth base I2. This process is repeated, and the subsequent offset distances are all the same as the second offset distance. Finally, femtosecond laser ablation is completed on the three-dimensional structural model, and the required multi-level T-shaped microstructure array II surface is obtained.

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

[0100] In this implementation, after the specific implementation, the surface powder, surface residues, and some surface defects in the 3D printed solid model I can be removed by ultrasonic cleaning, so that the surface of solid model I can achieve a better finish, which is beneficial 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 structural model is placed in an oven and dried at 60-120°C for 2-12 hours.

[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: processing the multi-level T-shaped microstructure array II using a reactive ion etching device to obtain a hydrophilic multi-level T-shaped microstructure array II, wherein the gas used for reactive ion etching is air, the flow rate of the gas used for reactive ion etching is 1 sccm, the radio frequency power is 1 W, and the reaction time is 0 min-99 min.

[0103] In this embodiment, specifically, reactive ion etching is used to etch a multi-level T-shaped microstructure array II. The surface of the multi-level T-shaped microstructure array II undergoes changes. On the one hand, under the action of radio frequency, plasma is formed by ionizing gas in a closed chamber and bombarding the object surface at high speed, allowing hydrophilic groups to adhere to the object surface and transforming it into a hydrophilic surface, thus achieving a wetting effect. On the other hand, reactive ion etching can further increase the surface roughness, thereby increasing its surface energy, which is conducive to the adsorption and spreading of water molecules on the surface, thereby improving hydrophilicity. Compared with the prior art, the process of the T-shaped microstructure array provided in this embodiment changing from hydrophobic to hydrophilic is very short, and complete wetting effect can be achieved without high radio frequency and high gas flow rate.

[0104] In the above embodiments, a multi-level T-shaped microstructure array II that can achieve the transformation from hydrophobic to hydrophilic state and controllable wetting is provided. The hydrophobic multi-level T-shaped microstructure array II is obtained by processing in steps S1 and S2, while the hydrophilic multi-level T-shaped microstructure array II is obtained by reactive ion etching processing in steps S1, S2 and 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 serve as a hydrophobic surface for self-cleaning windows and photovoltaic transparent shields. Water droplets on its surface form spherical beads, and due to the low adhesion of the surface, the beads roll under the influence of gravity or wind, carrying away dust and other contaminants during the rolling process, thus achieving a self-cleaning effect. It can also serve as a drag-reducing surface for ships and submarines; when an object moves in a fluid, the hydrophobic surface reduces the contact area between the object and the fluid, effectively reducing the fluid's viscous resistance. Furthermore, it can serve as the surface of waterproof clothing and textiles; the hydrophobic surface allows water droplets to form beads on the surface and roll off without penetrating the fabric, thus achieving waterproofing. Hydrophobic surfaces can be used for a variety of purposes. They can be applied to the hulls of ships, the steel structures of bridges, and the corrosion-resistant surfaces of chemical equipment, preventing direct contact between water and corrosive substances. They can also serve as antifreeze surfaces for outdoor equipment and power transmission lines, preventing water droplets from remaining and freezing, thus reducing ice formation. Furthermore, they can function as hydrophobic surfaces for heat exchangers, radiators, and heat pipes, altering fluid flow patterns and heat transfer methods to increase the convective heat transfer coefficient between the fluid and the surface. They can also be used as surfaces for micro / nano-scale fluid devices to regulate fluid flow behavior. Finally, they can be used as anti-biofouling surfaces for marine vessels and aquaculture facilities, reducing the adsorption of biomolecules 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 serve as hydrophilic microchannels in microfluidic chips and microchannel reactors, making the fluid flow more uniform and reducing fluid retention and clogging; it can also serve as an anti-fog surface for automotive glass, eyeglass lenses, and bathroom mirrors, where water vapor forms a uniform water film on the hydrophilic surface instead of condensing into water droplets, preventing fogging; it can also serve as the surface of water filtration membranes, oil-water separation membranes, and hemodialysis membranes to facilitate liquid separation; and it can also serve as the heat exchange surface of heat pipes and heat exchangers to enhance the heat exchange performance of the workpiece.

[0107] Please see Figure 5 and Figure 6 This invention provides a multi-level T-shaped microstructure array II, which is prepared by the above-described method for custom forming of 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 substrate II1. T-shaped microstructure II2 includes base II20 and multiple sheet II21. Multiple sheet II21 are provided on the top of base II20. The sidewalls of sheet II21 are located outside the sidewalls of base II20. There are gaps between multiple sheet II21.

[0110] In this embodiment, multiple sheets II 21 are located on top of the base II 20, and the sidewalls of the sheets II 21 are located outside the sidewalls of the base II 20 to form a T-shaped microstructure II 2; and a multi-layer structure with gaps is formed between the multiple sheets II 21, so that the surface area of ​​the multi-layer structure can be exposed as much as possible, effectively increasing the surface area of ​​the multi-level T-shaped microstructure array II for hydrophilic or hydrophobic applications.

[0111] In a hydrophilic application, multiple capillary channels are formed between the multilayer structure of multiple sheets II21. The capillary effect of the entire T-shaped microstructure array is strong. After water comes into contact with the T-shaped microstructure II2, the water will spread rapidly and evenly under the capillary action of the capillary channels, resulting in good hydrophilic properties.

[0112] In a hydrophobic application, the gaps formed between the multiple layers of sheet II21 trap air, creating a multi-layered air barrier. When water falls, it first contacts the air barrier, effectively increasing the contact angle and resulting in good hydrophobic performance.

[0113] As can be seen from the above process, in this embodiment, multiple sheets II 21 form a multi-layer structure on the base II 20, and gaps are formed between the multiple sheets II 21. Therefore, the surfaces of the multiple sheets II 21 can be fully exposed, which effectively increases the surface area of ​​the multi-level T-shaped microstructure array II. Compared with the existing T-shaped microstructure array with only a single-layer head structure, the surface area is larger and the hydrophobic and hydrophilic effects are better.

[0114] As an example, such as Figure 5 and Figure 6 As shown, a possible implementation of substrate II1 is further provided, wherein substrate II1 is one of a rectangle, a cylinder, or a frustum.

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

[0116] In one embodiment, such as Figure 5 and Figure 6 As shown, the groove wall of groove II10 is inclined towards the middle. For example, groove II10 can be a V-shaped groove or an arc-shaped groove II10. In specific implementation, groove II10 with an inclined surface that is inclined towards the middle has a larger surface area than ordinary diameter groove II10.

[0117] As an example, such as Figure 5 and Figure 6As shown, a further feasible method for realizing the T-shaped microstructure II2 is provided. The T-shaped microstructure II2 includes a base body II20 and multiple sheet bodies II21. At least one sheet body II21 is located at the top of the base body II20, and at least one sheet body II21 is inserted into the base body II20. For example, there are three sheet bodies II21, two of which are inserted into the base body II20, and one of which is located at the top of the base body II20. In specific implementation, the structure of the sheet body II21 and the base body II20 is more compact.

[0118] In one embodiment, such as Figure 5 and Figure 6 As shown, multiple sheet bodies II 21 are arranged along the height direction of the base body II 20, that is, a multi-layer sheet body II 21 structure is formed on the vertical cross-section of the base body II 20. In specific implementation, the multiple sheet bodies II 21 increase the surface area of ​​the base body II 20 in the height direction.

[0119] In one embodiment, multiple sheets II 21 are disposed on the top end face of the base body II 20, that is, multiple parallel filaments I 3 are formed on the top end face of the base body II 20. In specific implementation, the multiple sheets II 21 arranged on the top end face can increase the surface area in the horizontal direction.

[0120] In one specific embodiment, such as Figure 5 and Figure 6 As shown, in order to further increase the surface area of ​​sheet II 21, the side wall of sheet II 21 is inclined, with the inclined surface tilting upwards. In specific implementation, the side wall of sheet II 21 with an inclined surface has a larger surface area than a normal vertical wall.

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

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

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

[0124] In one embodiment, the distance between adjacent T-shaped microstructures II2 is 120 μm-240 μm; the base body II20 is a columnar or conical 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 II21 is 400 μm-1000 μm; and the distance of the gap I5 between adjacent sheets II21 is 100 μm-400 μm.

[0125] Example 1

[0126] Example 1 presents a multi-level T-shaped microstructure array II, which is fabricated using the personalized customization method described above. The specific steps include:

[0127] A1. Construct a virtual three-dimensional microstructure model and 3D print the three-dimensional microstructure model into a solid model I.

[0128] The solid model I has a base I1 in the shape of a rectangle with dimensions of 20 mm × 20 mm × 2 mm. The base I2 is shaped like a frustum, with a bottom face of 800 μm and a top face of 400 μm. The height is 400 μm. The distance between the bottom edges of any two adjacent bases I2 is 300 μm. The filament I3 is shaped like a cuboid with a short side of 400 μm, a length of 20 mm, and a height of 100 μm. Each base I2 has 3 filaments I3. The vertical spacing I4 between the filaments I3 on ​​each base I2 is 100 μm. The printing parameters include: printing accuracy of 100 μm, infill density of 100%, printing speed of 60 mm / s, infill pattern of concentric circles, and polyetheretherketone (PEEK) as the printing consumable.

[0129] A2. Place solid model I in an ultrasonic cleaner and perform ultrasonic cleaning in deionized water for 15 minutes. Then place solid model I in an oven and dry it at 120 °C for 6 hours.

[0130] A3. Using a femtosecond pulsed laser I7, the laser path is first positioned, and the center of the laser spot is aligned with the substrate I1. The laser spot is shifted to the right along the direction of the filament I3. The starting point of the shift is the left boundary marked on the direction of the filament I3, and the ending point is the center between the first and second bases I2 along the direction of the filament I3. Then, laser ablation is performed repeatedly along the direction perpendicular to the filament I3. The filaments I3 intersecting between the adjacent bases I2 are ablated and removed at the center, so that the filaments I3 break at the interval I4 between the two bases I2, forming a V-shaped groove on the model surface. The depth of laser ablation from the top of the filament I3 to the bottom of the V-shaped groove of the base is 900 μm. After laser ablation, the spacing between the broken 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 shifted to the right a certain distance for the second time. The distance is the side length of the bottom edge of base I2 plus the distance between the bottom edges of adjacent base I2. After the second offset, the center of the laser spot reaches the midpoint between the second and third base I2. The laser spot shifts to the same distance for the third time as the second time. After the shift, it reaches the midpoint between the third and fourth base I2. And so on. The subsequent offset distances are all the same as the second offset distance. Finally, femtosecond laser ablation is completed on solid model I, and the required multi-level T-shaped microstructure array II surface is obtained.

[0131] Example 2

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

[0133] Comparative Example 1

[0134] Comparative Example 1 presents a microstructure-free surface sample prepared by a molding machine. The molding heating temperature is 380℃ and the preheating time is 30 min. Polyether ether ketone is used as the material for preparing the microstructure-free surface.

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

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

[0137]

[0138] As shown in Table 1, in Example 1, the contact angle of the multi-level T-shaped microstructure array II before reactive ion etching was 130.9°. After reactive ion etching, the multi-level T-shaped microstructure array II had transformed into a completely wetted hydrophilic surface after 5 seconds of reactive ion etching. In Example 2, the contact angle of the multi-level T-shaped microstructure array II before reactive ion etching was 138.9°. After reactive ion etching, the multi-level T-shaped microstructure array II had transformed into a completely wetted hydrophilic surface after 5 seconds of reactive ion etching. The comparative sample without microstructures had a surface... The contact angle was 95.8°. After reactive ion etching, the contact angle of the structureless surface was 89.0° at a reactive ion etching time of 5s, which was only 6.8° lower than before reactive ion etching. The contact angle was 35.7° at an etching time of 180s, and 19.9° at etching times of 540s and 1080s. When the etching time was increased to 2160s, the contact angle of the structureless surface was 16.3°, which was only 3.6° lower. Although the reactive ion etching time was further increased, the hydrophilicity of the structureless surface was not significantly improved, and it was difficult to achieve a fully wetted state, that is, it was difficult to completely transform into a superhydrophilic surface.

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

[0140] In summary:

[0141] 1. The static contact angle of Example 2 (138.9°) is 8° higher than that of Example 1 (130.9°). The difference in 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 break spacing of Example 2 (240 μm) is twice as large as that of Example 1 (120 μm). It can be seen that a moderate increase in the spacing of T-shaped microstructures II2 in the range of 120 μm-240 μm can improve hydrophobicity.

[0142] II. The multi-level T-shaped microstructure array II prepared in Examples 1 and 2 has a significantly improved contact angle compared with the surface without microstructure. Furthermore, the time required for the hydrophobicity to hydrophilicity transition is short, and the required radio frequency power and gas flow rate are low. Unlike existing technologies, it does not require high frequency, high flow rate, and long time to complete the hydrophobicity to hydrophilicity transition.

[0143] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate 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 paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

Claims

1. A method for custom molding of multi-level T-shaped microstructure arrays, characterized in that, Includes the following steps: S1. Construct a virtual three-dimensional micron structure model and 3D print the three-dimensional micron structure model into a solid model; The solid model includes a base, multiple bases, and multiple filaments; the multiple bases are arranged in an array on the base, with gaps between adjacent bases; the multiple filaments are arranged in parallel on the arrayed bases, and multiple bases are connected to the same filament. S2, Based on the physical model, all portions of the filaments located at the intervals are removed by pulsed laser ablation to obtain a multi-level T-shaped microstructure array; During the process of ablation and removal of the portion of the filament located at the interval by pulsed laser, the pulsed laser ablates a groove on the substrate and burns an inclined surface on the filament, with the groove wall inclined towards the center.

2. The method according to claim 1, characterized in that, Multiple filaments are provided on the same base, and gaps are left between the multiple filaments on the same base.

3. The method according to claim 1, characterized in that, In step S2, all portions of the filaments located at the intervals are removed by pulsed laser ablation. Specifically, this step involves: S20, Align the center of the pulsed laser with the substrate; S21, along the direction of the filament, the pulsed laser is moved to an adjacent termination point, wherein the termination point is a point on the filament on a straight line perpendicular to the filament; S22, laser ablation is performed along the direction perpendicular to the filament to ablate and remove multiple filaments on the same straight line; S23, move the pulsed laser to the next termination point, and repeat steps S22 and S23 until the pulsed laser ablates and removes all portions of the filaments located in the interval.

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

5. The method according to claim 1, characterized in that, The length of the portion of the filament that is ablated and removed is 120 μm-240 μm.

6. The method according to claim 1, characterized in that, The pulsed laser is a femtosecond pulsed laser.

7. The method according to any one of claims 1 to 6, characterized in that, Following step S2, the following steps are also included: The multi-level T-shaped microstructure array was processed using a reactive ion etching (RIE) device to obtain a hydrophilic multi-level T-shaped microstructure array. The gas used for RIE was air, the flow rate of the gas was 1 sccm, the radio frequency power was 1 W, and the reaction time was less than 99 min.

8. An application of a hydrophobic structure, comprising a multi-level T-shaped microstructure array prepared by the method of any one of claims 1 to 6.

9. An application of a hydrophilic structure, using a multi-level T-shaped microstructure array prepared by the method of claim 7.

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