KR20220037987A - Manufacturing method and Manufacturing device for 3D structure using 2D-3D transformation - Google Patents

Abstract

The present invention relates to a method for manufacturing a three-dimensional (3D) structure and an apparatus for manufacturing the 3D structure. The method for manufacturing a 3D structure according to the present invention comprises the steps of: (a) fixing a two-dimensional (2D) structure on a substrate; (b) supplying a fluid to the substrate on which the 2D structure is fixed; and (c) making the 2D structure float by the fluid so as to form a 3D structure.

Description

Manufacturing method and manufacturing device for 3D structure using 2D-3D transformation

The present invention relates to a method and a manufacturing apparatus for manufacturing a 3D structure using 2D-3D transformation, and more specifically, to manufacturing a 3D structure by using a 2D-based manufacturing technique that is faster and simpler than a direct manufacturing technique of a 3D structure. It relates to a method and apparatus capable of doing so.

In general, as a method of manufacturing a three-dimensional structure, a mold method in which a liquid raw material is poured into a mold and the liquid raw material is solidified, a cutting method in which a three-dimensional solid material is directly cut and manufactured, and a two-dimensional structure having a thin thickness There is a layer-by-layer assembly method that manufactures a three-dimensional structure by stacking them. Among these methods, the multilayer thin film stacking method is a method widely used in 3D printing, and there are laser sintering (SLA, Stereo Lithography Apparatus) or FDM, Fused Deposition Modeling (FDM) using photocuring, and uses inexpensive raw materials. It is receiving attention recently because it can directly control its characteristics.

However, in the conventionally developed methods of manufacturing a 3D structure, a trade-off exists between rapid prototyping and productivity. For example, the mold method has a high production rate and thus has a low production cost per product, but requires a lot of time and money to design and manufacture the mold in the initial stage. In addition, 3D printing such as multi-layer thin film lamination method can rapidly manufacture 3D structures at very low initial cost, but it requires a lot of production time per product and is not suitable for mass production due to high unit cost.

On the other hand, 2D-3D deformation technology, which manufactures a three-dimensional structure by folding, bending, and assembling a two-dimensional sheet structure, is attracting attention as a technology that can make a three-dimensional structure easily, quickly, and inexpensively. In particular, 2D-3D transformation technology is suitable for mass production because it is based on fast and inexpensive 2D manufacturing technology. Accordingly, recently, self-folding origami, buckling, and 4D printing are actively developing technologies that transform a 2D structure into a self-designed 3D structure with a simple external stimulus.

However, the 2D-3D transformation technology developed so far often requires a more complicated process than the conventional 3D printing method in the process of preparing the two-dimensional structure, which is the material before transformation, so the practical application of the 2D-3D transformation technology is not possible. is limited

Republic of Korea Patent Publication No. 10-2019-0119218 Republic of Korea Patent Publication No. 10-2019-0073228

The present invention relates to a method for manufacturing a three-dimensional structure using 2D-3D transformation, which can manufacture a three-dimensional structure based on a two-dimensional structure faster and more conveniently than a conventional direct manufacturing method of a three-dimensional structure, or a 2D-3D transformation manufacturing method, and To provide a manufacturing device.

The present invention in order to solve the above problems, (a) fixing the two-dimensional structure to the substrate; (b) supplying a fluid to the substrate to which the two-dimensional structure is fixed; and (c) floating the two-dimensional structure by the fluid to form a three-dimensional structure.

Step (c) may further include increasing the strength of the formed three-dimensional structure.

The present invention may further include (d) adding functionality to the three-dimensional structure formed in step (c) by physical treatment or biochemical treatment.

The two-dimensional structure of step (c) may be partially or entirely suspended by the fluid.

The two-dimensional structure of step (c) may include a floating part part floating by the fluid and an anchor part part not floating by the fluid.

The floating part may be formed of an ink composition including a surfactant, and the anchor part may be formed of an ink composition that does not include a surfactant.

Each of the ink composition forming the floating part and the ink composition forming the anchor part may further include at least one selected from the group consisting of a polymerization initiator and a functional additive.

The fluid of step (b) may include at least one selected from the group consisting of a solvent, a monomer, a polymerization initiator, and a functional additive.

The functional additive is one selected from the group consisting of silver (Ag) particles, gold (Au) particles, iron (Fe) particles, neodymium (Nd) particles, quantum dots, biochemical molecules, and carbon nanotubes (CNT). It may include more than one species.

On the other hand, the present invention, a two-dimensional structure forming part for forming a two-dimensional structure; a fluid supply unit supplying a fluid to the two-dimensional structure forming unit to transform the two-dimensional structure into a three-dimensional structure; a recovery unit for recovering the three-dimensional structure; And it provides an apparatus for manufacturing a three-dimensional structure including a transfer unit for transferring the two-dimensional structure and the three-dimensional structure.

The manufacturing method of a three-dimensional structure using 2D-3D transformation according to the present invention is easy to manufacture and transforms a two-dimensional structure that can easily provide various functions into a three-dimensional structure to manufacture a three-dimensional structure. Manufacturing efficiency can be increased. Specifically, the present invention is a two-dimensional structure (material before deformation or a two-dimensional structure precursor) manufactured using a two-dimensional-based manufacturing technology, if it does not affect the structure indirectly or directly using a fluid (liquid or gas) In the process of transforming a two-dimensional structure, a three-dimensional structure can be easily formed.

Therefore, the present invention can be effectively applied to fields such as robots, bio, medical, semiconductor, circuit, toys, art, and architecture that require the manufacture of three-dimensional structures.

1 is a schematic diagram showing an apparatus for manufacturing a three-dimensional structure according to the present invention.
2 to 8 are reference diagrams for explaining the embodiments and application examples according to the present invention.

The terms or words used in the description and claims of the present invention should not be construed as being limited to their ordinary or dictionary meanings, and the inventor must properly understand the concept of the term in order to best describe his invention. Based on the principle that can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

In addition, the terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present invention, the terms include or have is intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features, number, step , it should be understood that it does not preclude in advance the possibility of the presence or addition of an operation, component, part, or combination thereof.

In addition, each step described in the present invention may be performed sequentially, in reverse order, or intersecting depending on the case, and between each step, a step in which progress is made to a level understood by a person skilled in the art may be added.

Unlike the prior art in which a two-dimensional structure, which is a material before deformation, was prepared through a complicated process for application of 2D-3D deformation technology, a two-dimensional structure can be easily and conveniently prepared, and the prepared two-dimensional structure can be prepared in three dimensions. It relates to a manufacturing method and manufacturing apparatus of a three-dimensional structure that can be easily transformed into a structure, which will be described in detail as follows.

A method of manufacturing a three-dimensional structure according to the present invention, (a) fixing the two-dimensional structure to a substrate; (b) supplying a fluid to the substrate to which the two-dimensional structure is fixed; and (c) floating the two-dimensional structure by the fluid to form a three-dimensional structure.

The step (a) is a step of fixing the two-dimensional structure, which is the material before deformation, to the substrate. Various methods may be applied to the method of fixing the two-dimensional structure to the substrate. Specifically, the fixing may include physical fixing using properties such as adhesiveness, dispersibility, magnetism, electrical properties, conductivity, semiconducting properties, electrostatic properties, viscosity, and hygroscopicity; chemical fixation using properties such as hydrophobicity, hydrophilicity, covalent bonding property, and functional group bonding property; And/or an immobilization method such as biochemical immobilization using properties such as biochemical molecular binding, antigen-antibody binding, receptor-ligand binding, etc. may be applied.

Here, the two-dimensional structure may be selectively fixed to the substrate. That is, according to the required shape (shape) of the 3D structure, the whole of the 2D structure may be fixed to the substrate, or a part of the 2D structure may be selectively fixed to the substrate.

The substrate to which the two-dimensional structure is fixed may be made of various components such as glass, metal, plastic (eg, polydimethylsiloxane (PDMS)), ceramic, and the like, and may have various shapes (eg, plate-shaped, columnar, polygonal). , conical, circular, oval, etc.).

The two-dimensional structure fixed to the substrate refers to a material before being transformed into a three-dimensional structure, and may be referred to as a two-dimensional structure precursor. Such a two-dimensional structure may have a thin film structure, a plate-shaped structure (single-layer structure), or a multi-layer structure, and may have various shapes according to a required shape of the three-dimensional structure.

The two-dimensional structure may be manufactured by various methods. Specifically, the two-dimensional structure is a two-dimensional printing method such as a pen, a brush, inkjet printing, laser printing, stamping (stamping); two-dimensional cutting methods such as scissors, knives, paper cutters, laser cutters, ultrasonic cutters, hydraulic cutters, etc.; chemical surface treatment methods such as vapor deposition, coating, and the like; physical thin film manufacturing methods such as electrospinning, solvent evaporation, and dip coating; and/or a method for manufacturing a two-dimensional structure in a semiconductor process such as photocuring, thermal curing, spin coating, or etching.

In addition, the two-dimensional structure may be made of various components. Specifically, the two-dimensional structure is a thermosetting polymer, a photocurable polymer, an ion-curable polymer, a hydrogel, silicon, silicon oxide, silicon nitride, a negative/positive photoresist crystalline material to which an epoxy substrate polymer is applied, nano It may contain a component consisting of a mixture of substances, plastics, metals, nucleic acids, peptides, polypeptides, proteins, liposomes, and combinations thereof.

Such a two-dimensional structure may include a floating part and an anchor part, which will be described later in detail.

Step (b) is a step of supplying a fluid to the substrate on which the two-dimensional structure is fixed in order to induce deformation of the two-dimensional structure. The fluid may be a commonly known liquid or gas.

The liquid is not particularly limited, but specifically, a polar solvent such as water, ethanol, methanol, acetone, polyethylene glycol (PEG), isopropyl alcohol (IPA); non-polar solvents such as cyclohexane, carbon tetrachloride, benzene and the like; non-reactive solvents such as silicone oil and mineral oil; and/or functional solutions such as potassium hydroxide (KOH), sulfuric acid (H ₂ SO ₄ ), hydrofluoric acid (HF), ammonium hydroxide (NH ₄ OH), hydrochloric acid (HCl), hydrogen peroxide (H ₂ O ₂ ), CMP slurry, etc. can be

The gas is not particularly limited, but specifically air, oxygen (O ₂ ), hydrogen (H ₂ ), chlorine (Cl ₂ ), carbon tetrachloride (CCl ₄ ), dichlorodifluoromethane (CF ₂ Cl ₂ ) and/or an inert gas (eg, argon (Ar), helium (He), etc.).

Here, in order to smoothly induce the deformation of the two-dimensional structure and increase the strength of the deformed structure, the fluid may be a composition including at least one selected from the group consisting of a solvent, a monomer, a polymerization initiator, and a functional additive.

The solvent included in the composition is not particularly limited, but specifically, a polar solvent such as water, ethanol, methanol, acetone, polyethylene glycol (PEG), etc.; non-polar solvents such as cyclohexane, carbon tetrachloride, benzene and the like; And it may be at least one selected from the group consisting of non-reactive solvents such as silicone oil, mineral oil, and the like.

The monomer included in the composition is not particularly limited, but specifically ethylene glycol, propylene glycol, acrylamide, ethyl acrylate, methyl acrylate, trimethylolpropane ethoxylate triacrylate, 3-(tri Methoxysilyl)propyl acrylate (3-(trimethoxysilyl)propyl acrylate), 3-glycidoxypropylmethoxysilane, vinyltrimethylsilane, vinyltriethylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, trime Toxysilylpropyl (meth)acrylate, divinylsilane, trivinylsilane, dimethyldivinylsilane, divinylmethylsilane, methyltrivinylsilane, diphenyldivinylsilane, divinylphenylsilane, trivinylphenylsilane, divinyl Methylphenylsilane, tetravinylsilane, dimethylvinyldisiloxane, poly(methylvinylsiloxane), poly(vinylhydrosiloxane), poly(phenylvinylsiloxane), allyloxy-t-butyldimethylsilane, allyloxytrimethylsilane, allyltrie Toxysilane, allyltri-iso-propylsilane, aryltrimethoxysilane, allyltrimethylsilane, aryltriphenylsilane, diethoxymethylvinylsilane, diethylmethylvinylsilane, dimethylethoxyvinylsilane, dimethylphenylvinylsilane, ethoxy Cydiphenylvinylsilane, methylbis(trimethylsilyloxy)vinylsilane, triacetoxyvinylsilane, triethoxyvinylsilane, triethylvinylsilane, triphenylvinylsilane, tris(trimethylsilyloxy)vinylsilane, vinyloxytrimethyl Silane, glucosamine, polydimethylsiloxane, agarose, agar, polyethylene glycol dimethacrylate (PEGDMA), polypropylene glycol diacrylate (PPGDA), polypropylene glycol dimethacrylate (PPGDMA), 2-hydroxyethyl methacrylate (HEMA), acrylic acid (acrylic acid), styrene, vinyl amide, vinyl ether, and may be at least one selected from the group consisting of polyethylene glycol diacrylate (PEGDA) . Such a monomer may mean a polymerization reaction raw material in which a polymerization reaction occurs by a polymerization initiator.

The polymerization initiator included in the composition is not particularly limited as long as it is a commonly known polymerization initiator, but specifically benzophenone, 4-methoxybenzophenone, 2-Hydroxy-4′-(2- hydroxyethoxy)-2-methylpropiophenone (Irgacure-2959), 2-Hydroxy-2-methylpropiophenone (DAROCUR 1173), α-ketoglutaric acid, benzoyl peroxide, azobisisobutyronitrile (azobisisobutyronitrile), ammonium persulfate (ammonium persulfate) and potassium persulfate (potassium persulfate) may be at least one selected from the group consisting of.

The functional additive included in the composition is not particularly limited, but specifically silver (Ag) particles, gold (Au) particles, iron (Fe) particles, neodymium (Nd) particles, quantum dots (quantum dots), biochemical molecules (eg, For example, it may be one or more selected from the group consisting of cells, DNA, protein, antibody, etc.) and carbon nanotubes (CNTs). By including such a functional additive, the strength of the three-dimensional structure formed by the deformation of the two-dimensional structure may be increased. In addition, additional functionality may be imparted to the three-dimensional structure according to the physical, chemical, magnetic or biochemical properties of the functional additive.

Step (c) is a step of forming a three-dimensional structure through a process in which the two-dimensional structure is suspended by the fluid. That is, part or all of the two-dimensional structure is separated and suspended from the substrate by the fluid, and the structure of the two-dimensional structure is deformed in three dimensions during the floating process to form a three-dimensional structure. Here, the mechanism by which the two-dimensional structure is deformed into three dimensions is specifically, physical deformation using properties such as adhesion, dispersibility, magnetic, electrical, conductive, semiconducting, electrostatic, viscous, and hygroscopic; chemical modification using properties such as hydrophobicity, hydrophilicity, covalent bonding properties, and bonding properties of functional groups; It may be a modification using a biochemical reaction such as biochemical molecular binding, antigen-antibody binding, receptor-ligand binding, and the like.

For example, when the fluid is a liquid, the deformation mechanism may use interfacial energy. Specifically, a part or all of the two-dimensional structure may be suspended by using the interfacial energy of the two-dimensional structure before deformation to be transformed into a three-dimensional structure. Here, the interfacial energy may mean using a hydrophilic-hydrophobic interface interaction or surface tension.

On the other hand, the two-dimensional structure may be entirely suspended by a fluid or a part thereof may be floated. In this case, when a part is floated, the two-dimensional structure may include a floating part and an anchoring part. can That is, the two-dimensional structure includes a floating part part floating by the fluid and an anchor part part not floating by the fluid. The floating part is a part that is separated from the substrate and floats, and the anchor part is a part that is not separated from the substrate and maintains a fixed state. As such, the two-dimensional structure includes the floating part and the anchor part. When it meets this fluid, it is possible to form a more three-dimensional three-dimensional structure.

Controlling the floating degree of the floating part and the anchor part by the fluid may be implemented in various ways. For example, the adjustment of the floating degree may be implemented by adjusting the interface energy between each of the floating part and the anchor part and the substrate. Specifically, when the two-dimensional structure is formed, a floating part is formed with an ink composition containing a surfactant, and an anchor part is formed with an ink composition that does not contain a surfactant to control the interface energy between each part and the substrate, and thus the fluid By supplying the , the floating degree of each part can be adjusted. Here, the surfactant included in the ink composition for forming the floating part is not particularly limited as long as it is a commonly known surfactant (eg, Tween, Span, etc.).

More specifically, the ink composition forming the floating part may be an ink composition including a binder resin, a surfactant, a polymerization initiator, a plasticizer, a solvent, a functional additive and a pigment, and the ink composition forming the anchor part may include a surfactant It may be an ink composition including the excluded binder resin, polymerization initiator, plasticizer, solvent, functional additive and pigment.

The binder resin, plasticizer, and solvent included in each ink composition are not particularly limited as long as they are commonly known components.

The polymerization initiator included in each ink composition is not particularly limited as long as it is a commonly known polymerization initiator, but specifically benzophenone, 4-methoxybenzophenone, 2-Hydroxy-4′-( 2-hydroxyethoxy)-2-methylpropiophenone (Irgacure-2959), 2-Hydroxy-2-methylpropiophenone (DAROCUR 1173), α-ketoglutaric acid, benzoyl peroxide, azobisisobuty It may be at least one selected from the group consisting of ronitrile (azobisisobutyronitrile), ammonium persulfate (ammonium persulfate), and potassium persulfate (potassium persulfate).

The functional additive included in each ink composition is not particularly limited, but specifically silver (Ag) particles, gold (Au) particles, iron (Fe) particles, neodymium (Nd) particles, quantum dots, biochemical molecules ( For example, it may be one or more selected from the group consisting of cells, DNA, protein, antibody, etc.) and carbon nanotubes (CNTs). By including such a functional additive, the strength of the three-dimensional structure formed by the deformation of the two-dimensional structure may be increased. That is, the step of increasing the strength of the three-dimensional structure to be described later may be implemented. For example, the functional additive acts as a polymerization catalyst for the monomers included in the fluid, and as the polymer coating of the 3D structure is made, the strength of the 3D structure is increased. In addition, additional functionality may be imparted to the three-dimensional structure according to the physical, chemical, magnetic or biochemical properties of the functional additive.

The content of the functional additive included in each ink composition may be 50% by weight or less based on the total weight% of each ink composition. Specifically, the content of the functional additive may be 10 to 50% by weight, more specifically 30 to 40% by weight, based on the total weight% of each ink composition. As the functional additive is included within the above range, it is possible to smoothly impart desired functionality to the three-dimensional structure while ensuring the viscosity of each ink composition.

This step (c) may further include increasing the strength of the formed three-dimensional structure. That is, the three-dimensional structure itself formed by floating the two-dimensional structure by a fluid may not exhibit the strength required depending on the field of application. Accordingly, the present invention can increase the applicability of the three-dimensional structure by performing a process of increasing the strength in the process of forming the three-dimensional structure.

Various methods may be applied to the method of increasing the strength of the three-dimensional structure. Specifically, methods for increasing the strength of the three-dimensional structure include polymer coating, dip coating, chemical strengthening, work hardening, precipitation hardening, dispersion strengthening ( dispersion strengthening), grain boundary strengthening (grain boundary strengthening), strain hardening (transformation hardening), fiber reinforcement (fiber reinforcement), etc. are mentioned.

When the strength of the three-dimensional structure is increased through the polymer coating, the polymer to be coated is polyethylene glycol (PEG), polyacrylamide, polymethoxyethyl acrylate, trimethylolpropane ethoxylate triacrylate, 3-(trimethoxysilyl)propyl acrylate (3-(trimethoxysilyl)propyl acrylate), chitosan, polydimethylsiloxane (PDMS), agarose, agar, polyethylene glycol diacrylate (PEGDA) etc. The polymer coating may be implemented by, for example, applying a composition including at least one selected from the group consisting of the above-described solvent, monomer, polymerization initiator and functional additive as a fluid. That is, when the composition is applied as a fluid, on the surface of the three-dimensional structure formed while the two-dimensional structure is suspended and the three-dimensional structure is formed, the monomer included in the composition is a polymerization initiator and/or functional additive (eg, iron particles). ), a polymerization reaction occurs and the surface of the three-dimensional structure is coated with a polymer.

The present invention may further include a step (step (d)) of adding functionality by subjecting the three-dimensional structure formed in step (c) to physical treatment or biochemical treatment. Specifically, physical treatment or biochemical treatment of the three-dimensional structure can be used to obtain adhesion, dispersibility, magnetic properties, electrical properties, conductivity, semiconducting properties, electrostatic properties, viscosity, hygroscopicity, hydrophobicity, hydrophilicity, covalent bonding, biochemical molecules, antigen-antibody, Various functionalities, such as receptor-ligands, can be imparted.

In addition, in the present invention, a two-dimensional or three-dimensional process may be additionally performed on the three-dimensional structure obtained through step (c) or step (d).

Meanwhile, the present invention provides a manufacturing apparatus for manufacturing the above-described three-dimensional structure. Specifically, the apparatus for manufacturing a three-dimensional structure according to the present invention includes: a two-dimensional structure forming unit for forming a two-dimensional structure; a fluid supply unit supplying a fluid to the two-dimensional structure forming unit to transform the two-dimensional structure into a three-dimensional structure; a recovery unit for recovering the three-dimensional structure; and a transfer unit for transferring the two-dimensional structure and the three-dimensional structure.

The two-dimensional structure forming unit included in the apparatus for manufacturing a three-dimensional structure according to the present invention forms a two-dimensional structure, and is not particularly limited as long as it has a structure capable of forming a two-dimensional structure. As an example, referring to FIG. 1 , the two-dimensional structure forming unit 10 according to the present invention may have a structure formed by printing a two-dimensional structure. In addition, the ink composition may be drawn on the substrate to form a two-dimensional structure.

The fluid supply unit included in the apparatus for manufacturing a three-dimensional structure according to the present invention transforms a two-dimensional structure into a three-dimensional structure by supplying a fluid to the two-dimensional structure, especially if it has a structure capable of supplying a fluid to the two-dimensional structure not limited As an example, referring to FIG. 1 , the fluid supply unit 20 according to the present invention may have a structure having a bath in which a fluid (a composition (monomer solution)) is poured.

The recovery unit included in the apparatus for manufacturing a three-dimensional structure according to the present invention recovers the three-dimensional structure, and is not particularly limited as long as it has a structure capable of manually or automatically recovering the three-dimensional structure.

The transfer unit included in the apparatus for manufacturing a three-dimensional structure according to the present invention transfers the two-dimensional structure and the three-dimensional structure, and the structure thereof is not particularly limited. As an example, referring to FIG. 1 , the transfer unit 30 according to the present invention may have a structure of a conveyor belt that can continuously transfer a two-dimensional structure and a three-dimensional structure.

The apparatus for manufacturing a three-dimensional structure according to the present invention includes: a reinforcing unit capable of increasing the strength of the three-dimensional structure; and a functional addition unit capable of imparting physical or biochemical functionality to the three-dimensional structure.

The apparatus for manufacturing a three-dimensional structure according to the present invention can continuously manufacture a two-dimensional structure, which is a material before deformation, and perform 2D-3D deformation, so it is efficient for a mass production process of a three-dimensional structure or a rapid prototyping process can be introduced as For example, as shown in FIG. 1 , as the three-dimensional structure was manufactured using the roll-to-roll process (R2R) to which a conveyor belt was applied, it was possible to form 60 three-dimensional structures on a large human-sized substrate within 30 minutes. This is the realization of mass production of 3D structures, which was difficult to mass-produce with conventional 3D·4D printing technology.

As described above, when a three-dimensional structure is manufactured with the manufacturing method and manufacturing apparatus according to the present invention, the three-dimensional structure can be easily manufactured, and various functionalities (physical, chemical, biochemical, etc.) can be imparted to the three-dimensional structure. Therefore, it can be effectively applied to the manufacture of robots, actuators, works of art, semiconductors, circuit devices, and the like. For example, by giving magnetic properties to a three-dimensional structure, it can be used in the manufacture of robots, actuators, works of art, semiconductors, circuit devices, etc. that can operate with magnetic force.

Hereinafter, the present invention will be described in more detail by way of Examples. However, the following examples are intended to illustrate the present invention, and it is apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and the scope of the present invention is not limited thereto.

[Example]

1) Formation and fixation of two-dimensional structures

In a two-dimensional space, the pen is the most convenient and familiar tool for expressing designs (ideas) with a high degree of freedom. Pen drawing has advantages such as accessibility and freedom. In addition, it is suitable for realizing mass production by grafting 2D-based printing technologies that have been developed a lot so far. Accordingly, in the embodiment of the present invention, a three-dimensional structure was manufactured by applying pen drawing, which facilitates the formation of a two-dimensional structure.

Specifically, in order to form a three-dimensional structure after designing a two-dimensional structure as shown in FIG. 2, a two-dimensional structure was drawn using a pen containing an ink composition on a plastic substrate as shown in FIG. 3A. In this case, the floating part is an ink composition including a polyvinyl butyral (PVB) resin, a surfactant, a plasticizer, a solvent, and other additives (antifoaming agent, viscosity modifier, pigment, etc.), and an anchoring part ) does not contain a surfactant, and the drawing was made with an ink composition containing polyvinyl butyral (PVB) resin, a plasticizer, a solvent, and other additives (antifoaming agent, viscosity modifier, pigment, etc.). Here, the composition and pen drawing structure of each ink composition are as shown in FIG. 4 . After the drawing and drying, a two-dimensional structure having a hydrophobic thin film structure was formed and fixed on a substrate.

2) Supply of fluid to the 2D structure

A substrate on which a two-dimensional structure having a hydrophobic thin film structure was formed was put into a bath containing a fluid, a monomer solution, to supply a fluid to the two-dimensional structure. As the monomer solution, a composition containing water (0.75 g/ml), polyethylene diacrylate (PEGDA 700) (0.28 g/mL), and potassium persulfate (2 mg/mL) was used.

3) Forming a 3D structure through floating and deforming a 2D structure

By putting the 2D structure into a bath containing the monomer solution, the interfacial energy between the 2D structure and the substrate was controlled, and a part of the 2D structure was suspended and deformed to form a 3D structure. That is, the three-dimensional structure is formed through a deformation mechanism in which selective exfoliation and floating occurs by surface tension of the two-dimensional structure formed of the ink composition.

Specifically, referring to FIG. 3B , while the monomer solution penetrates the interface between the two-dimensional structure and the substrate, the two-dimensional structure is selectively separated (exfoliated) from the substrate by capillary force. Thereafter, the two-dimensional structure separated from the substrate floats to the surface of the monomer solution by surface tension and maintains its state. Here, the occurrence of the separation (delamination) is controlled by the adhesive force between the two-dimensional structure and the substrate, and the control of the adhesion may vary depending on whether a surfactant is present in the ink composition used to form the two-dimensional structure. In this embodiment, the floating part drawn with the ink composition containing a surfactant has lower adhesion to the substrate than the anchor part drawn with the ink composition not containing the surfactant, so after the two-dimensional structure meets the monomer solution, The floating part was separated from the substrate and floated on the surface of the monomer solution, and the anchor part remained fixed without being separated from the substrate.

Hereinafter, the principle of separating (separating) the floating part and the anchor part from the substrate will be described in more detail as follows.

When the 2D structure of the hydrophobic thin film structure is added to the monomer solution, whether the 2D structure is separated depends on the work of adhesion (W) between the 2D structure and the substrate. For example, since the two-dimensional structure of the hydrophobic thin film structure is relatively hydrophobic compared to the substrate, a hydrophilic fluid (monomer solution) permeates between the two-dimensional structure and the substrate by capillary action, thereby exfoliating the two-dimensional structure. . This phenomenon may vary depending on the angle between the fluid and the substrate, viscosity, interfacial energy, hydrophobicity of the two-dimensional structure, and the like. In order to separate the two-dimensional structure of the thin film structure from the substrate, a crack must occur between the two-dimensional structure and the substrate. In order to induce a crack between the 2D structure and the substrate, the correct mechanical energy required to separate each interface must exceed the work (W) required to separate each interface at equilibrium, where W can be defined as there is.

W = γSL + γLF-γSF.

(W: adhesion action, γSL: substrate-liquid interface energy, γLF: liquid-film interface energy, γSF: substrate-film interface energy)

Here, if a surfactant is used, the W value can be lowered, and when the W value is lowered, the two-dimensional structure can be easily removed. In addition, it is also possible to perform selective separation (exfoliation) of the two-dimensional structure depending on the presence or absence of a surfactant. Accordingly, in this embodiment, an ink composition containing a surfactant and an ink composition not containing a surfactant were used when the two-dimensional structure was formed.

It can be confirmed that the three-dimensional structure having various shapes can be manufactured as shown in FIG. 5 by selectively determining the floating part part and the anchor part part as in the present embodiment. Specifically, by introducing computer-aided design (CAD) and automatic printing systems, more accurate production or mass production is possible, and the initial structure can be predicted through simulation.

4) Reinforcement of 3D structures

In order to increase the strength of the three-dimensional structure, the formed three-dimensional structure was coated with a polymer. The polymer coating was Surface initiated Polymerization (SIP) (Ma, S. et al. Continuous Surface Polymerization via Fe(II)-Mediated Redox Reaction for Thick Hydrogel Coatings on Versatile Substrates. Adv. Mater. 30, 1803371 (2018)). proceeded through. Specifically, referring to FIG. 6 , a two-dimensional structure is formed by mixing iron particles with each ink composition for forming a floating part and an anchor part, and then it is added to a solution in which potassium persulfate (KPS), a polymerization initiator, and a monomer are mixed. When input, the 2D structure is transformed into a 3D structure, and the polymerization reaction is accelerated near the site by the iron particles present in the 2D structure, and the deformed 3D structure is coated with a polymer.

Referring to FIG. 7 , it can be seen that the stiffness of the three-dimensional structure is increased by 1000 times after the polymer coating. In addition, it can be seen that a thicker and stronger structure is formed according to the concentration of iron particles. However, when the content of iron particles is 50 wt % or more, the ink composition including iron particles does not naturally spread on the surface of the substrate. On the other hand, although the thickness of the coated polymer increased with the incubation time in the monomer solution (the elapsed time after injection), it was confirmed that 3 minutes was sufficient for the purpose of securing the strength of the three-dimensional structure. In applying the SIP process, it was derived that the optimal weight of iron particles in the ink composition and the incubation time of the two-dimensional structure were 40 wt% and about 3 minutes, respectively.

[Application example]

Since the present invention forms a two-dimensional structure using a pen and transforms it into a three-dimensional structure, the degree of freedom of selection of a substrate to which the two-dimensional structure is fixed is very high. That is, referring to FIG. 8 , a two-dimensional structure is formed by applying a material such as gloves, stones, leaves, etc. as a substrate, drawing with a pen on it, and then separating and floating using a fluid. It can be confirmed that a dimensional structure can be formed (refer to a of FIG. 8 ). Furthermore, a pop-up three-dimensional structure can be manufactured even in a narrow-necked bottle, also called an 'impossible bottle' (see Fig. 8b).

Due to such applicability, the present invention can mass-produce a three-dimensional structure using various materials as a substrate without almost any restrictions on the environment for manufacturing the three-dimensional structure. In addition, since the volume of the 2D structure, which is the material before deformation, is much smaller than the volume of the 3D structure, high-density packaging and simple delivery may be possible.

In summary, according to this embodiment, since the present invention is to manufacture a three-dimensional structure through pen-based 4D printing, it is possible to easily and intuitively manufacture a three-dimensional structure in a situation that does not require much specialized knowledge.

Above, the specific part of the present invention has been described in detail, and for those of ordinary skill in the art, this specific description is only a preferred embodiment, and the scope of the present invention is not limited thereby. will be clear Accordingly, it is intended that the substantial scope of the present invention be defined by the appended claims and their equivalents.

10: two-dimensional structure forming part
20: fluid supply unit
30: transfer unit

Claims (11)

(a) fixing the two-dimensional structure to the substrate;
(b) supplying a fluid to the substrate to which the two-dimensional structure is fixed; and
(c) floating the two-dimensional structure by the fluid to form a three-dimensional structure. According to claim 1,
The (c) step is a method of manufacturing a three-dimensional structure further comprising the step of increasing the strength of the formed three-dimensional structure. According to claim 1,
(d) subjecting the three-dimensional structure formed in step (c) to physical treatment or biochemical treatment to further include the step of adding functionality. According to claim 1,
The two-dimensional structure of step (c) is a method of manufacturing a three-dimensional structure that is partially or entirely suspended by the fluid. The method of claim 1,
The two-dimensional structure of step (c) is a method of manufacturing a three-dimensional structure comprising a floating part part floating by the fluid and an anchor part part not floating by the fluid. 6. The method of claim 5,
The floating part is formed of an ink composition containing a surfactant, and the anchor part is formed of an ink composition that does not contain a surfactant. 7. The method of claim 6,
Each of the ink composition forming the floating part and the ink composition forming the anchor part further comprises at least one selected from the group consisting of a polymerization initiator and a functional additive. 8. The method of claim 7,
The functional additive is one selected from the group consisting of silver (Ag) particles, gold (Au) particles, iron (Fe) particles, neodymium (Nd) particles, quantum dots, biochemical molecules, and carbon nanotubes (CNT). A method for manufacturing a three-dimensional structure comprising more than one species. According to claim 1,
The fluid of step (b) is a method of manufacturing a three-dimensional structure comprising at least one selected from the group consisting of a solvent, a monomer, a polymerization initiator and a functional additive. 10. The method of claim 9,
The functional additive is one selected from the group consisting of silver (Ag) particles, gold (Au) particles, iron (Fe) particles, neodymium (Nd) particles, quantum dots, biochemical molecules, and carbon nanotubes (CNT). A method for manufacturing a three-dimensional structure comprising more than one species. a two-dimensional structure forming unit for forming a two-dimensional structure;
a fluid supply unit supplying a fluid to the two-dimensional structure forming unit to transform the two-dimensional structure into a three-dimensional structure;
a recovery unit for recovering the three-dimensional structure; and
An apparatus for manufacturing a three-dimensional structure including a transfer unit for transferring the two-dimensional structure and the three-dimensional structure.

Images