A method for preparing voxelized multi-material structures based on capillary cascade effect

Abstract

The present invention discloses a method for preparing a voxelized multi-material structure based on the capillary cascade effect. The above-mentioned preparation method includes the following steps: S1 constructing a lattice unit model with different implosion pressures in software and arranging them in three dimensions, and using a 3D printer to print out the arranged lattice units to obtain a microlattice structure; S2 injecting a precursor solution into the microlattice structure and filling its internal space; S3 depositing the precursor solution in the target lattice unit based on the capillary cascade effect by liquid depletion; S4 solidifying the precursor solution deposited in the target lattice unit to form a single-material voxel structure; S5 repeating steps S2-S4, sequentially depositing and solidifying different precursor solutions in lattice units with different implosion pressures, to complete the preparation of the voxelized multi-material structure. The purpose of the present invention is to provide a voxelized multi-material preparation method that can be completed with high precision and speed using simple equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of voxelized multi-material printing, and in particular to a method for preparing a voxelized multi-material structure based on a capillary cascade effect. Background Art

[0002] Voxelated Multi-Materials Printing (VMP), an emerging technology in 3D printing, has demonstrated tremendous potential across multiple industries in recent years. Its core advantage lies in its ability to precisely control the composition and functionality of different materials at the voxel level, enabling the printing of highly complex multi-material structures. This has led to widespread interest and exploration in fields such as manufacturing, medicine, aerospace, and electronic engineering. Compared to traditional single-material 3D printing, VMP utilizes multiple materials and enables precise control over their position, morphology, function, and distribution during the printing process. This allows for greater diversity and complexity in printed structures and the ability to meet the demands of higher-performance applications. However, despite its significant theoretical potential, VMP faces a number of technical challenges in practical application, primarily in areas such as material rheology regulation, printing precision control, equipment complexity, and material interface stability.

[0003] Currently, extrusion-based 3D printing technology dominates multi-material printing. This method builds multi-material structures voxel by voxel by layer using different types of inks or raw materials. However, extrusion-based 3D printing faces numerous bottlenecks in achieving high-resolution printing.

[0004] The complexity of the equipment is also one of the main problems faced by VMP technology in practical applications. Traditional multi-material printing methods usually require multiple nozzles or multi-channel systems to spray different materials at the same time. This not only makes the configuration of the equipment more complicated, but also increases the cost and difficulty of maintenance of the equipment. For example, in a pressure-driven printing system, the nozzle needs to be adjusted in real time according to the rheological properties of different materials. This complex adjustment process not only requires the nozzle to have high-precision control capabilities, but also requires an efficient system to ensure that different materials can be output smoothly. If the nozzle cannot be accurately adjusted, it may cause problems such as material blockage or nozzle damage during the printing process. Although light-curing technology can achieve higher resolution, it also faces many challenges in multi-material printing. In order to perform multi-material printing on each layer, it is usually necessary to replace the liquid tank containing different materials, which not only increases the complexity of the equipment, but also increases the difficulty of maintenance and operation.

[0005] One of the more difficult problems is the interface problem between materials during multi-material printing. The differences in the physical and chemical properties of different materials, such as elastic modulus, thermal expansion coefficient, chemical reactivity, etc., often lead to instability or uneven interface of materials at the bonding site. This phenomenon is particularly evident in the printing of high-performance structures, which may lead to reduced strength of the final structure, differences in thermal performance, or even functional failure. For example, when the interface between the printed materials is not properly handled, poor interface contact or discontinuous transition areas between materials may occur, thus affecting the overall performance of the multi-material structure. Therefore, how to achieve a good interface transition between materials during multi-material printing, ensure that each material can be tightly combined, and achieve coordination in performance, has become a difficult problem that must be solved technically.

[0006] When it comes to adjusting the rheological properties of multiple materials, most existing technologies face the problems of insufficient precision and difficult operation. Rheological adjustment is one of the key factors affecting the effect of multi-material printing, especially in the process of printing with multiple materials at the same time. The accuracy of rheological adjustment directly determines the stability and consistency of printing quality. Current technologies usually adjust the rheological properties of materials by changing the pressure, temperature or other parameters of the print head, but these methods are often difficult to meet the precise requirements when printing multiple materials at the same time. In addition, the rheological properties of materials are closely related to factors such as their formula and molecular structure, which makes fine-tuning different materials a complex task.

[0007] In addition to the aforementioned challenges, VMP technology also faces efficiency challenges. Traditional multi-material printing, due to its voxel-by-voxel construction method, is relatively inefficient. This is particularly true when building complex structures, as the voxel-by-voxel, layer-by-layer printing process typically takes a long time to complete. This is clearly inefficient for applications requiring large-scale production.

[0008] Based on the above, there is an urgent need for a method that can complete fast, high-precision, and clear-interface multi-material 3D printing with simple equipment. Summary of the Invention

[0009] The object of the present invention is to provide a voxelized multi-material preparation method that can be completed with high precision and speed using simple equipment.

[0010] A first aspect of the present invention is:

[0011] Provided is a method for preparing a voxelized multi-material structure.

[0012] The second aspect of the present invention is:

[0013] Provided is an ion hydrogel power source.

[0014] A 3D printing system.

[0015] The present invention also provides a 3D printing system.

[0016] Specifically, the technical solution adopted according to the first aspect of the present invention is:

[0017] A method for preparing a voxelized multi-material structure comprises the following steps:

[0018] S1 constructs lattice unit models with different implosion pressures in the software and arranges them in three dimensions. The arranged lattice units are then printed using a 3D printer to obtain a microlattice structure.

[0019] S2 injecting the precursor solution into the microlattice structure and filling the internal space thereof;

[0020] S3 uses liquid depletion to allow the precursor solution to continuously flow into the lattice units with low implosion pressure based on the capillary cascade effect during the depletion process, and ultimately only deposit in the target lattice units with the lowest implosion pressure;

[0021] S4 solidifies the precursor solution deposited in the target lattice unit to form a single-material voxel structure;

[0022] S5 repeats steps S2-S4, sequentially depositing and solidifying different precursor solutions in lattice units with different implosion pressures to complete the preparation of the voxelized multi-material structure.

[0023] According to the embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0024] The present invention constructs a microlattice structure by arranging lattice units with different implosion pressures. The precursor solution is then filled into the microlattice structure, avoiding the creation of gaps due to incomplete filling that could affect the capillary cascade effect. Through liquid depletion, the capillary cascade effect causes liquid to continuously flow into the lattice unit with the lowest implosion pressure during depletion. When liquid is present only in the structure with the lowest implosion pressure, the liquid depletion process is stopped, and the liquid in the structure with the lowest implosion pressure is solidified to form a single-material voxel structure. By sequentially depositing and solidifying different precursor solutions, precise liquid deposition between each unit is achieved, ultimately completing the precise construction of multiple materials, enabling high-precision and rapid voxelized multi-material construction.

[0025] The method of the present invention effectively solves technical problems existing in existing multi-material printing, such as equipment complexity, low printing accuracy, slow printing speed, and rheological limitations of extrusion printing materials.

[0026] The capillary cascade effect works in the microlattice structure of the present invention as follows: For the lattice structure, the droplet will change its own morphology in an energy-minimizing manner based on surface tension, volume, structural hydrophilicity, etc. When the volume is large enough, a cube will be formed within the lattice structure. As the volume gradually decreases, the gas-liquid interface will gradually sink inward. Under the competing effects of the liquid cohesion and the adhesion between the liquid and the lattice structure, the cubic droplet will eventually implode. This process is significantly affected by the lattice structure. Using the internal pressure of the droplet during the implosion as a representation, the flow conditions when the liquid is exhausted when the lattice structures are interconnected can be predicted. This flow is the capillary cascade effect.

[0027] Definition of implosion pressure: As a droplet gradually decreases in size within the lattice structure, its gas-liquid interface sinks inward, exhibiting negative pressure within the droplet. Implosion occurs when the volume reaches its limit. The internal pressure corresponding to this volume is the critical rupture pressure. This value is then divided by the internal pressure of the spherical droplet corresponding to the volume of the lattice unit, and the resulting dimensionless number is defined as the implosion pressure.

[0028] According to one embodiment of the present invention, the method of depositing the precursor solution in the target lattice unit based on the capillary cascade effect by liquid depletion includes the following steps: the precursor solution in the microlattice structure is gradually depleted by liquid depletion, and during the depletion process, due to the different implosion pressures of the lattice units in the microlattice structure, the implosion will occur from high to low according to the implosion pressure, and the lattice unit with high implosion pressure will be the first to rupture. After the implosion, the remaining precursor solution flows into the lattice unit with slightly lower implosion pressure. As the liquid depletion proceeds, the lattice unit with slightly lower implosion pressure implodes, and the remaining liquid flows into the lattice unit of the next level again. Finally, the liquid is deposited in the target lattice unit, and the liquid depletion is stopped at this time.

[0029] According to one embodiment of the present invention, the microlattice structure is a hydrophilic microlattice structure. The surface of the hydrophilic microlattice structure has high hydrophilicity, which can effectively avoid the situation where the precursor solution cannot fully fill the lattice due to structural hydrophobicity.

[0030] According to one embodiment of the present invention, the hydrophilic treatment comprises oxygen plasma modification or liquid-like surface coating.

[0031] According to one embodiment of the present invention, the liquid depletion method is selected from either evaporation or suction. This method gradually depletes the liquid within the microlattice structure, which is filled with the precursor solution. Due to the capillary cascade effect, the liquid is deposited at pre-designed spatial points. These two different and controllable liquid depletion methods are used to accommodate different scales (micrometers / millimeters) and material properties, thereby simplifying operation and improving precision.

[0032] According to one embodiment of the present invention, the microlattice structure is printed by projection microstereolithography (PμSL), digital light processing (DLP) or two-photon polymerization (TPP) technology with a printing accuracy of 160nm-37μm.

[0033] According to one embodiment of the present invention, the type of lattice unit includes one of a face-centered cubic lattice (fcc), a simple cubic lattice (sc), and a body-centered cubic lattice (bcc). Preferably, the type of lattice unit includes at least a face-centered cubic lattice (fcc), because the capillary cascade phenomenon is significantly more sensitive to the aspect ratio of the face-centered cubic lattice than that of the simple cubic and body-centered cubic lattices.

[0034] According to one embodiment of the present invention, the lattice unit is selected from a simple cubic, body-centered cubic, and face-centered cubic structure, and / or the aspect ratio of the lattice unit is 3.3-10. By optimizing the design of the lattice type and parameters, the controllability of the capillary cascade effect is enhanced, ensuring precise material deposition. The aspect ratio of the lattice unit is the ratio of the length to the diameter of the pillars constituting the lattice unit.

[0035] According to one embodiment of the present invention, the lattice side length of the lattice unit is 20 μm-2 mm.

[0036] According to one embodiment of the present invention, when the contact angle of the precursor solution is 30°, the difference in implosion pressure between lattice units with different dimensionless implosion pressures in the microlattice structure is greater than 0.19. Dimensionless implosion pressure is referred to as implosion pressure in the present invention.

[0037] According to one embodiment of the present invention, when the contact angle of the precursor solution is 30°, the implosion pressure values ​​of different lattice units at aspect ratios of 10, 5, or 3.3 are shown in Table 1.

[0038] Table 1

[0039]

[0040] Where L is the strut length and D is the strut diameter, both in mm. For example, L2D0.4 means the strut length is 2 mm and the strut diameter is 0.4 mm.

[0041] According to one embodiment of the present invention, the precursor solution includes at least one of a photosensitive resin, a polyethylene glycol diacrylate aqueous solution, and a polyacrylamide (PAM) hydrogel precursor, and a photoinitiator is added to the precursor solution. By adapting the multi-material precursor solution, the range of printable materials is broadened and the reliance on material rheology is reduced.

[0042] According to one embodiment of the present invention, the components of the precursor solution include polyethylene glycol diacrylate PEGDA and 2-hydroxy-2-methylphenyl acetone.

[0043] According to one embodiment of the present invention, the components of the precursor solution include a photosensitive resin.

[0044] According to one embodiment of the present invention, the components of the precursor solution include polyacrylamide, MN,N'-methylenebisacrylamide and 2-hydroxy-2-methylphenylacetone.

[0045] According to one embodiment of the present invention, the components of the precursor solution include a mixed solution of high temperature resistant resin and anhydrous ethanol in a volume ratio of 1:3.

[0046] According to one embodiment of the present invention, the components of the precursor solution include a mixed solution of standard resin and anhydrous ethanol in a volume ratio of 1:3.

[0047] According to an embodiment of the present invention, in step S4, the curing includes UV curing, which uses UV curing to cure the liquid material into a solid state to form a spatially voxelized single-material structure.

[0048] According to one embodiment of the present invention, the UV curing has a curing time of 30-60 seconds, and the UV light irradiation covers each surface of the lattice structure.

[0049] Specifically, the technical solution adopted according to the second aspect of the present invention is:

[0050] An ionic hydrogel power source includes the voxelized multi-material structure prepared by the method for preparing the voxelized multi-material structure, wherein the regions of the ionic hydrogel power source include a high-salt region, a low-salt region, a cation-selective region, and an anion-selective region, and the regions are arranged in series or in parallel through a capillary cascade effect.

[0051] According to the embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0052] The ionic hydrogel power supply of the present invention can simplify the preparation process of the bionic power supply, realize seamless connection of the ionic conductive channels, and improve output performance.

[0053] A 3D printing system, comprising a single-material 3D printer, a microlattice modeling module, a precursor solution injection device, a liquid depletion control module, and a UV curing device, is used to perform the aforementioned method for fabricating voxelized multi-material structures. This invention reduces equipment complexity and improves multi-material printing efficiency through an integrated system design.

[0054] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0056] Figure 1 This is a flow chart of the method for preparing the millimeter-scale voxelized multi-material structure in Example 1-2.

[0057] Figure 2 Flowchart of the method for preparing the micron-scale voxelized multi-material structure in Examples 3-4.

[0058] Figure 3 Schematic diagram of the lattice structure used in the ionic hydrogel power supply in Example 5.

[0059] Figure 4 This is a graph showing the change in open circuit voltage of the unit structure over time in Example 5.

[0060] Figure 5 This is a graph showing the short-circuit current of the unit structure in Example 5 changing with time.

[0061] Figure 6 Dimensionless open-circuit voltage and short-circuit current diagrams of the unit structure and the two-unit structure in Example 5. DETAILED DESCRIPTION

[0062] In the description of the present invention, if there is a description of first, second, or 1, 2, etc., it is only used to distinguish the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0063] The terms "preferred," "more preferred," and the like, used herein refer to embodiments of the present invention that may provide certain benefits under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the present invention.

[0064] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein are understood to include any and all subranges subsumed therein.

[0065] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of the present invention.

[0066] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0067] In the examples and comparative examples, the microlattice structure was printed by the following method:

[0068] First, modeling is performed in 3D modeling software, and then the microlattice structure is obtained through projection micro-stereolithography (PμSL), digital light processing (DLP) or two-photon polymerization (TPP) 3D printing.

[0069] Among them, the printing accuracy of PμSL, DLP and TPP are 10μm, 37μm and 160nm respectively. The first two are used to print millimeter-level voxelized material preparation frames, and the latter is used to print micron-level frames.

[0070] In the examples and comparative examples, the microlattice structure was hydrophilized by the following methods:

[0071] The printed microlattice structure is placed in an oxygen plasma treatment device for surface hydrophilic modification (plasma treatment) for 5 minutes. The treated surface has a high hydrophilicity, which can effectively avoid the situation where structural hydrophobicity causes the droplets to be unable to fill the lattice.

[0072] In an embodiment, a method for liquid-like surface modification of a micron-scale microlattice structure comprises the following steps:

[0073] First, micrometer-scale microstructures were fabricated on a glass substrate via two-photon polymerization (Nanoscribe, Photonic Professional GT2), with the temperature controlled at 25°C. The glass and its printed structures then underwent a liquid-like surface modification to prevent excess liquid from accumulating. The modification solution consisted of a mixture of isopropyl alcohol, dimethyldimethoxysilane, and sulfuric acid in a mass ratio of 100:10:1. The glass surface was then treated with oxygen plasma and immersed in the prepared modification solution for 5 seconds. Excess liquid was removed using absorbent paper. The sample was allowed to air dry at room temperature and then rinsed sequentially with water, isopropyl alcohol, and cyclohexane.

[0074] The micron-scale microlattice structure and the glass substrate are modified through liquid-like surface. Since the surface of the glass substrate has undergone liquid-like modification, its ability to retain liquid is greatly weakened. Therefore, only the area where the micron-scale microlattice structure is located will capture part of the precursor solution liquid.

[0075] The precursor solutions used in the examples and comparative examples are:

[0076] Precursor solution 1: 50% by volume of PEGDA (polyethylene glycol diacrylate) aqueous solution and 2% by volume of 2-hydroxy-2-methylpropiophenone (as a photoinitiator) based on the total mass of the precursor solution.

[0077] Precursor solution 2: Anycubic standard photosensitive resin;

[0078] Precursor solution 3: 5.5 mol / L acrylamide, 0.066 mol / L N,N'-methylenebisacrylamide (crosslinker), and 0.615 mol / L 2-hydroxy-2-methylphenylacetone (photoinitiator).

[0079] Precursor solution 4: comprising BMF HTL-Y high temperature resistant resin and anhydrous ethanol in a volume ratio of 1:3;

[0080] Precursor solution 5: The components include Anycubic standard resin and anhydrous ethanol in a volume ratio of 1:3.

[0081] The gel precursor solution used to prepare the ionic hydrogel power source in the embodiment is:

[0082] High saline gel precursor solution: composed of a mixture of 0.5 mol / L NaCl, 5.4 mol / L acrylamide, 0.067 mol / L bis (N,N'-methylenebisacrylamide) and 0.0615 mol / L photoinitiator.

[0083] Low-salt water gel precursor solution: composed of a mixture of 0.015 mol / L NaCl, 5.5 mol / L acrylamide, 0.066 mol / L bis, and 0.615 mol / L photoinitiator.

[0084] Cationic selective hydrogel precursor solution: composed of a mixture of 2 mol / L 2-acrylamido-2-methylpropane sulfonic acid, 3.7 mol / L acrylamide, 0.045 mol / L bis, and 0.0615 mol / L photoinitiator.

[0085] Anion-selective hydrogel precursor solution: composed of a mixture of 2 mol / L (3-acrylamidopropyl) trimethylammonium chloride, 2.75 mol / L acrylamide, 0.034 mol / L bis, and 0.0615 mol / L photoinitiator.

[0086] In the examples and comparative examples, the implosion pressure values ​​of different cubic lattices at different aspect ratios are shown in Table 1:

[0087] Table 1

[0088]

[0089] Where L is the length of the pillar and D is the diameter of the pillar, both in mm.

[0090] In the following examples, lattice structure dimensions are expressed as "lattice type + aspect ratio + (implosion pressure)." For example, fcc5(-3.75) represents a face-centered cubic lattice with an aspect ratio of 5 and an implosion pressure of -3.75, while bcc5(-1.19) represents a body-centered cubic lattice with an aspect ratio of 5 and an implosion pressure of -1.19.

[0091] Example 1

[0092] A method for preparing a millimeter-scale voxelized multi-material structure, the flow chart is as follows Figure 1 As shown, the following steps are included:

[0093] S1. Nine structural units, including face-centered cubic (fcc), body-centered cubic (bcc), and simple cubic (sc), were modeled in SolidWorks software, with pillars 2 mm long and diameters of 0.2 mm, 0.3 mm, and 0.4 mm, respectively. The lattice structural units were arranged three-dimensionally in SolidWorks according to the required multi-material configuration. Fcc5 (-3.75), fcc10 (-1.96), and sc5 (-1.15) were selected as example structural units. The parts were assembled into an assembly and saved as an STL file. The lattice structure was 3D printed using Anycubic M3 Max and cleaned with anhydrous ethanol. The microlattice structure was plasma treated to ensure its hydrophilicity.

[0094] S2, filling the internal space of the microlattice structure with the prepared precursor solution 1 (PEGDA-aqueous solution);

[0095] S3, use the needle to aspirate at fcc5 (face-centered cubic unit structure with an aspect ratio of 5), and stop when the liquid gradually implodes and exists only in fcc5;

[0096] S4, use UV lamp to cure each face of the fcc5 cube for 30 seconds, clean it with anhydrous ethanol, water, and anhydrous ethanol in turn, and blow dry the surface with nitrogen;

[0097] S5, fill the microlattice structure with precursor solution 2 (Anycubic standard resin), then use a needle to aspirate at fcc10 (face-centered cubic unit structure with an aspect ratio of 10), stop when the liquid gradually implodes and exists only in fcc10, then use UV lamp to cure each face of the cube for 30 seconds, use anhydrous ethanol, water, and anhydrous ethanol in turn to clean, and blow dry the surface with nitrogen;

[0098] S6, fill the prepared precursor solution 3 (PAM hydrogel precursor solution) to the entire microlattice structure, then use a needle to aspirate at sc5, and stop after the excess liquid on the outer surface of the lattice is removed. Then use a UV lamp to cure each face of the cube for 30 seconds, and use anhydrous ethanol, water, and anhydrous ethanol to clean it in turn, and blow dry the surface with nitrogen.

[0099] Example 2

[0100] A method for preparing a millimeter-scale voxelized multi-material structure, the flow chart is as follows Figure 1 Specifically, the following steps are included:

[0101] A1. Three structural units, fcc5 (face-centered cubic, aspect ratio of 5, implosion pressure of -3.75), fcc10 (face-centered cubic, aspect ratio of 10, implosion pressure of -1.96), and fcc3.3 (face-centered cubic, aspect ratio of 3.3, implosion pressure of -7.13), with 2mm pillar lengths, were modeled in SolidWorks. The lattice units were arranged in three dimensions in SolidWorks according to the required multi-material configuration, the parts were assembled into an assembly, and the resultant structure was saved as an STL file. The lattice structure was 3D printed using Anycubic M3 Max and cleaned with anhydrous ethanol. The microlattice structure was then plasma treated to ensure its hydrophilicity.

[0102] A2, fill the internal space of the microlattice structure with the prepared precursor solution 1 (PEGDA-aqueous solution);

[0103] A3, using a needle to draw suction at fcc3.3 (face-centered cubic, aspect ratio of 3.3, implosion pressure of -7.13), the droplet implosions, driven by capillary cascade phenomena, occurred sequentially, first in the fcc10 lattice, then in the fcc5 lattice, and stopped when the liquid gradually imploded only in the fcc3.3 lattice;

[0104] A4, use UV lamp to cure each surface of the cube for 30 seconds, clean it with anhydrous ethanol, water, and anhydrous ethanol in turn, and blow dry the surface with nitrogen;

[0105] A5: Fill the microlattice structure completely with precursor solution 2 (Anycubic standard resin). Then, use a needle to draw liquid from the fcc5 (face-centered cubic unit structure with an aspect ratio of 5). Stop when the liquid gradually implodes and exists only in the fcc5. Then, use a UV lamp to cure each face of the cube for 30 seconds. Wash with anhydrous ethanol, water, and anhydrous ethanol in turn, and blow dry the surface with nitrogen.

[0106] A6, fill the prepared precursor solution 3 (PAM hydrogel precursor solution) to the entire microlattice structure, then use a needle to aspirate at fcc10, stopping after the excess liquid on the outer surface of the lattice is removed. Then use a UV lamp to cure each face of the cube for 30 seconds, and use anhydrous ethanol, water, and anhydrous ethanol to clean it in turn, and blow dry the surface with nitrogen.

[0107] Example 3

[0108] A method for preparing micron-scale voxelized multi-material structures, the flow chart is as follows Figure 2 As shown, Figure 2 Figure a is a schematic diagram of the printing frame structure. Figure 2Figure b is a schematic diagram of the unit structure filled with HTL resin precursor solution. Figure 2 c is a schematic diagram of the unit structure of the HTL resin after curing. Figure 2 d in the figure is a schematic diagram of the unit structure filled with TRU resin precursor solution. Figure 2 e in FIG. 1 is a schematic diagram of a unit containing HTL resin and TRU resin after curing.

[0109] Specifically, the following steps are included:

[0110] B1. Nine structural units, including face-centered cubic (fcc), body-centered cubic (bcc), and simple cubic (sc), were modeled in SolidWorks software, with pillars of 20 μm in length and diameters of 2 μm, 3 μm, and 4 μm. Fcc5 (-3.75), fcc10 (-1.96), and sc5 (-1.15) were selected as structural units for the example. The lattice structural units were arranged three-dimensionally in SolidWorks according to the required multi-material configuration. The parts were assembled into an assembly and saved as an STL file. The microlattice structure was printed on a glass substrate using Nanoscribe and Photonic Professional GT2. The glass and microlattice structure were cleaned with anhydrous ethanol, water, and anhydrous ethanol. The microlattice structure and the glass substrate were plasma treated to ensure hydrophilicity. The microlattice structure was subjected to liquid-like surface modification. After modification, the lattice structure and the glass substrate were placed on a 10° inclined plane.

[0111] B2, the precursor solution 4 is dropped onto the glass substrate, including the area where the 3D-printed microlattice structure is located. Since the surface of the glass substrate has undergone liquid-like modification, its ability to retain liquid is greatly weakened, and only the area where the lattice structure is located will capture some liquid;

[0112] B3. After all the liquid on the surface has drained away, place the glass substrate and the microlattice structure on a 90°C graphite hotplate to dry to completely remove any remaining alcohol. The remaining non-volatile resin will remain in the fcc5 (face-centered cubic unit structure with an aspect ratio of 5).

[0113] B4, cure the microlattice structure and glass substrate with a UV lamp for 30 seconds, clean the lattice structure and glass substrate with anhydrous ethanol, and dry them. Place the lattice structure and glass substrate on a 10° inclined plane;

[0114] B5, dropwise adding the precursor solution 5 onto the glass substrate, including the area where the 3D printed lattice structure is located;

[0115] B6: After all the liquid on the surface has drained away, place the glass substrate and lattice structure on a 90°C graphite hotplate to dry to completely remove any remaining alcohol. The remaining non-volatile resin will remain in sc5.

[0116] B7, the lattice structure and the glass substrate were cured with a UV lamp for 30 seconds, the lattice structure and the glass substrate were cleaned with anhydrous ethanol, and dried to obtain the final sample.

[0117] Example 4

[0118] A method for preparing micron-scale voxelized multi-material structures, the flow chart is as follows Figure 2 Specifically, the following steps are included:

[0119] C1: Modeling fcc10 (face-centered cubic, aspect ratio of 10, implosion pressure of -1.96) and sc5 (simple cubic, aspect ratio of 5, implosion pressure of -1.15) structural units with 20 μm pillar lengths in SolidWorks software. Three-dimensionally arrange the lattice structural units in SolidWorks according to the required multi-material configuration, assemble the parts into an assembly, and save the assembly as an STL file. Print the microlattice structure onto a glass substrate using Nanoscribe and Photonic Professional GT2. Clean the glass and microlattice structure with anhydrous ethanol, water, and anhydrous ethanol. Plasma-treat the microlattice structure and the glass substrate to ensure hydrophilicity. Liquid-like surface modification was then performed on the microlattice structure. After modification, the lattice structure and the glass substrate were placed on a 10° inclined plane.

[0120] C2, the precursor solution 4 is dripped onto the glass substrate, including the area where the 3D-printed microlattice structure is located. Since the surface of the glass substrate has undergone liquid-like modification, its ability to retain liquid is greatly weakened, and only the area where the lattice structure is located will capture some liquid;

[0121] After all the liquid on the surface has drained away, the glass substrate and the microlattice structure are placed on a 90°C graphite hotplate for drying to completely remove any remaining alcohol. The remaining non-volatile resin will remain in the fcc10 (face-centered cubic unit structure with an aspect ratio of 10).

[0122] C4, the micro-lattice structure and the glass substrate were cured with a UV lamp for 30 seconds, the lattice structure and the glass substrate were cleaned with anhydrous ethanol, and dried, and the lattice structure and the glass substrate were placed on a 10° inclined plane;

[0123] C5, dropping the precursor solution 5 onto the glass substrate, including the area where the 3D printed lattice structure is located;

[0124] After all the liquid on the surface has drained away, place the glass substrate and the lattice structure on a 90°C graphite hotplate to dry to completely remove any remaining alcohol. The remaining non-volatile resin will remain in sc5.

[0125] C7, the lattice structure and the glass substrate were cured with a UV lamp for 30 seconds, the lattice structure and the glass substrate were cleaned with anhydrous ethanol, and dried to obtain the final sample.

[0126] Example 5

[0127] An ion hydrogel power supply, wherein the power supply unit of the ion hydrogel power supply consists of a first high-salt region, a cation selective region, a low-salt region, an anion selective region and a second high-salt region to form a four-material matrix.

[0128] As attached Figure 3 As shown, attached Figure 3 This is a schematic diagram of the structure of the ionic hydrogel power supply, which includes a unit structure, a two-unit structure in series, and a two-unit structure in parallel. The ionic hydrogel power supply uses the capillary cascade effect to prepare an electric eel-like power supply in a framework composed of fcc10, fcc6, fcc4.29, and fcc3.33. The ionic hydrogel power supply can measure the open circuit voltage. V oc (varies with the increase of series connected cells) and short circuit current I sc (Changes with the increase of parallel units), the seamless interface connection bridges the ion conduction channel, generating a diffusion potential under the action of the ion gradient. Figure 4 The open circuit voltage of the unit structure changes with time. It can be seen from the figure that as time increases, the open circuit voltage of the ionic hydrogel power supply increases from 60mV to 55mV and tends to be stable. Figure 5 The short-circuit current of the unit structure changes with time. Figure 5 It is known that as time increases, the short-circuit current gradually decreases. Figure 6 The dimensionless open circuit voltage and short circuit current diagrams of the unit structure and the two-unit structure (two units in parallel and two units in series) are shown. 、 are the voltage and current values ​​obtained by dimensionless conversion based on the open-circuit voltage and short-circuit current of a unit structure.

[0129] The preparation method of the above-mentioned ionic hydrogel power supply comprises the following steps:

[0130] D1, four lattices were modeled in SolidWorks with pillars of 2 mm in length and diameters of 0.2 mm, 0.333 mm, 0.466 mm, and 0.6 mm, respectively: fcc10 (face-centered cubic with an aspect ratio of 10, implosion pressure of -1.96), fcc6 (face-centered cubic with an aspect ratio of 6, implosion pressure of approximately -2.855), fcc4.29 (face-centered cubic with an aspect ratio of 4.29, implosion pressure of approximately -5.44), and fcc3.33 (face-centered cubic with an aspect ratio of 3.33, implosion pressure of -7.13). ; Arrange these four lattice structures side by side from left to right in the order of fcc10, fcc3.33, fcc4.29, fcc6 and fcc10 as a unit; For the parallel-series structure, use fcc10 as the link to connect multiple units (to ensure that the ionic hydrogel power supply starts working after all hydrogels are arranged (to prevent unnecessary ion migration), use fcc10 (high salt concentration part) as the connecting unit, and deposit the high salt concentration part (the part with high ion concentration) in the last step); Use Anycubic M3 Max3D to print the lattice structure, clean the structure with anhydrous ethanol; The lattice structure is plasma treated to ensure the hydrophilicity of the structure;

[0131] D2, the lattice structure is filled with the prepared cationic selective permeable hydrogel precursor, and then aspirated at the position of fcc3.3 with a needle. The liquid is stopped when it gradually implodes and exists only in fcc3.3. Then, it is cured with a UV lamp for 30 seconds on both sides;

[0132] D3, the prepared low-concentration saline gel precursor is filled into the lattice structure, and then a needle is used to aspirate at the position of fcc4.29. The liquid is stopped when it gradually implodes and exists only in fcc4.29. Then, a UV lamp is used to cure it on both sides for 30 seconds each;

[0133] D4, the lattice structure is filled with the prepared anion-selective hydrogel precursor, and then aspiration is performed at the position of fcc6 with a needle. The liquid is stopped when it gradually implodes and exists only in fcc6. Then, a UV lamp is used to cure it on both sides for 30 seconds each;

[0134] D5, the lattice structure is filled with the prepared cationic selective permeable hydrogel precursor, and then a needle is used to aspirate on the fcc10 at one end to remove the excess precursor solution on the entire power source surface. Then, a UV lamp is used to cure the front and back sides for 60 seconds each to prepare an ionic hydrogel power source;

[0135] D6. After the hydrogel power supply is prepared, wires are inserted into the fcc10 structures at both ends to provide power.

[0136] Comparative Example 1

[0137] The difference between Comparative Example 1 and Example 1 is that in Comparative Example 1, a bcc (body-centered cubic) and sc (simple cubic) structure with a pillar length of 2 mm and a diameter of 0.4 mm was modeled in SolidWorks software.

[0138] Since the microlattice structure of Comparative Example 1 only contains sc5 (implosion pressure of -1.15) and bcc5 (implosion pressure of -1.19) unit structures, and the implosion pressure difference is too small (implosion pressure difference is 0.04), the precursor solution will be randomly deposited during the liquid depletion process, and therefore, a voxelized multi-material structure cannot be constructed.

[0139] Comparative Example 2

[0140] The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, a bcc (body-centered cubic) and sc (simple cubic) structure with a pillar length of 2 mm and a diameter of 0.2 mm was modeled in SolidWorks software.

[0141] Since the microlattice structure of Comparative Example 2 only contains sc10 (implosion pressure of -0.76) and bcc10 (implosion pressure of -0.76) structures, the implosion pressure difference is too small (implosion pressure difference is 0), which will cause the precursor solution to be randomly deposited during the liquid depletion process. Therefore, it is impossible to construct a voxelized multi-material structure.

[0142] Performance testing:

[0143] Traditional voxelized multi-material 3D printing faces numerous limitations. For example, 1mm precision extrusion printing, which relies on multiple nozzles or a single nozzle with multiple channels, is limited by the complexity of nozzle design, stringent requirements for material rheology, and the difficulty of coordinating pressure control and nozzle movement in real time. Furthermore, DLP printing, which relies on a constantly changing liquid tank, suffers from slow printing speeds and complex setup requirements due to the need to clean and replace the tank after each layer and material.

[0144] This invention leverages the capillary cascade effect to achieve voxelized multi-material printing without specialized equipment. This method extends point-by-point or layer-by-layer printing to phase-by-phase printing (printing one material at a time), enabling a three-step process for printing voxelized three-material structures. This broadens the range of manufacturable materials, eliminates the need to consider material rheological properties, and simultaneously increases voxel resolution by 100 times.

[0145] The above are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention specification, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing a voxelized multi-material structure, characterized by: The following steps are involved: S1 constructs lattice unit models with different implosion pressures in the software and arranges them in three dimensions. The arranged lattice units are then printed using a 3D printer to obtain a microlattice structure. S2 injecting the precursor solution into the microlattice structure and filling the internal space thereof; S3 uses liquid depletion to allow the precursor solution to continuously flow into the lattice units with low implosion pressure based on the capillary cascade effect during the depletion process, and ultimately only deposit in the target lattice units with the lowest implosion pressure; S4 solidifies the precursor solution deposited in the target lattice unit to form a single-material voxel structure; S5 repeats steps S2-S4, sequentially depositing and solidifying different precursor solutions in lattice units with different implosion pressures to complete the preparation of the voxelized multi-material structure; When the contact angle of the precursor solution is 30°, the difference in implosion pressures of lattice units with different dimensionless implosion pressures in the microlattice structure is greater than 0.

19.

2. The method according to claim 1, wherein: The micro lattice structure is a hydrophilic treated micro lattice structure.

3. The method according to claim 1, wherein: The liquid depletion mode is selected from one of evaporation and suction.

4. The method according to claim 1, wherein: The type of the lattice unit includes one of a face-centered cubic lattice (fcc), a simple cubic lattice (sc), and a body-centered cubic lattice (bcc).

5. The method according to claim 4, characterized in that: The lattice unit is selected from simple cubic, body-centered cubic and face-centered cubic structures, and / or the aspect ratio of the lattice unit is 3.3-10.

6. The method according to claim 4, characterized in that: The lattice side length of the lattice unit is 20 μm-2 mm.

7. The method according to claim 1, wherein: The precursor solution includes at least one of a photosensitive resin, a polyethylene glycol diacrylate aqueous solution, and a polyacrylamide hydrogel precursor, and a photoinitiator is added to the precursor solution.

8. An ion hydrogel power supply, characterized in that: The voxelized multi-material structure is prepared by the method for preparing a voxelized multi-material structure according to any one of claims 1 to 7, wherein the regions of the ionic hydrogel power supply include a high-salt region, a low-salt region, a cation-selective region, and an anion-selective region, and each region is arranged in series or in parallel through a capillary cascade effect.

9. A 3D printing system, characterized in that: The invention comprises a single-material 3D printer, a microlattice modeling module, a precursor solution injection device, a liquid depletion control module and an ultraviolet curing device, and is used to execute the method for preparing a voxelized multi-material structure according to any one of claims 1 to 7.

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