KR20200108704A - Fabrication method of 3 dimensional structure with triply periodic minimal surfaces based on bead arrays - Google Patents

Abstract

The present invention relates to a method for manufacturing a 3D structure with triply periodic minimal surfaces (TPMS) based on a bead arrangement, and more particularly, to a geometric shape of a bead arrangement for realizing TPMS and a method thereof. The bead arrangement is formed by forming a reference layer pattern, putting at least one sub-layer pattern into contact with an upper or lower portion of the reference layer pattern, and then bonding contact portions between all the beads constituting the reference layer pattern and the sub-layer pattern, and the sub-layer pattern has a projection surface pattern identical to or different from the reference layer pattern. According to the present invention, a 3D structure having another TPMS such as a D surface and an N-14 surface, and a 3D thin film porous structure using the same as a sacrificial structure may be manufactured in a mass-producible manner, and a technology related to the production of ″Shelluar″ of an ideal TPMS and an application range thereof can be further expanded. In addition, a technical concept of the reference layer pattern and sub-layer pattern introduced for arranging beads when implementing the D and N-14 surfaces and matters concerning a mechanical design of a reference plate used when forming the reference layer pattern can be applied when implementing other TPMS.

Description

Manufacturing method of a 3D structure with a 3-cycle minimum curved surface based on an array of beads {FABRICATION METHOD OF 3 DIMENSIONAL STRUCTURE WITH TRIPLY PERIODIC MINIMAL SURFACES BASED ON BEAD ARRAYS}

The present invention relates to a method of manufacturing a three-dimensional structure having a three-cycle minimum curved surface based on a bead arrangement, and more particularly, to a geometric shape of a bead arrangement for realizing a three-cycle minimum curved surface and a method thereof. The three-dimensional structure may be used as a template, and thus, may be used to fabricate a three-dimensional thin-film porous structure.

Recently, Seung-cheol Han and others introduced a three-dimensional thin-film porous structure called “Shellular” composed of a thin film (Seung Chul Han, Jeong Woo Lee, Kiju Kang, “A New Type of Low Density Material; Shellular”, Advanced Materials, Vol. 27, pp.5506-5511, 2015.), this “Shellular” is known to be very light and high in strength because a certain unit cell is repeated periodically and is composed of a thin film.

As an example of the “Shelluar”, Korean Patent No. 1612500 discloses a three-dimensional thin-film porous structure having a'curved surface' cell structure and a method of manufacturing the same. Specifically, the Korean Patent No. 1612500 discloses a three-dimensional structure by attaching and connecting the beads to each other after placing a plurality of beads in contact with each other (Fig. 1 (a)), and using the three-dimensional structure as a sacrificial structure (template ) To form a thin film on the surface and then remove the sacrificial structure therein, thereby finally manufacturing a three-dimensional thin film porous structure having a'curved' cell structure (Fig. 1(b)). Figure 1 (a) is a three-dimensional structure corresponding to the sacrificial structure, Figure 1 (b) is a three-dimensional thin film porous structure of a'curved' cell structure manufactured using the sacrificial structure of Figure 1 (a). Respectively. In this case, manufacturing a three-dimensional structure corresponding to the sacrificial structure involves applying a separate liquid resin between the beads in connection with a method of attaching and connecting a plurality of arranged beads to each other, and using a capillary phenomenon to soften the contact between the beads. It is performed by a method of hardening after forming a fillet (refer to Fig. 2), and in a 3D thin-film porous structure with a final'curved' cell structure using the manufactured sacrificial structure, the connection between unit cells is implemented in a smooth shape, thereby reducing stress concentration. Thus, it is disclosed that the strength and rigidity are remarkably increased.

Meanwhile, as the ideal form of the “Shellular” mentioned above, the German mathematician H.A. Schwarz's first discovered Triply Periodic Minimal Surface (TPMS) is known (Gesammelte Mathematische Abhandlungen, Springer). TPMS is a curved surface having a constant mean curverture at all points on the curved surface. Here, the average curvature refers to the average value of the maximum and minimum curvatures in two directions perpendicular to each other at a point on the 3D surface. TPMS exists in various forms as shown in FIG. 3, of which P-surface and D-surface shown in the upper left of FIG. 3 are most representatively cited in the fields of chemistry and biology. In addition, TPMS with a zero mean curvature has the same optimal ratio of interior and exterior spaces as 1:1, but even if the volume ratio is different, if the average curvature is uniform, the curvature of the minimum surface area for a given interior/external space ratio is Because it is formed, it can be called TPMS (Reference: M. Maldovan and EL Thomas, “Periodic Materials and Interference Lithography, 2009 WILEY-VCH Verlag GmbH & Co. KGaA, ISBN: 978-3-527-31999-2). As such TPMS has a uniform average curvature everywhere on a curved surface, when an external load is applied to a thin film structure manufactured in the form of TPMS, the stress is not concentrated in any one part. Therefore, the premature local buckling phenomenon that occurs in conventional ultra-low density materials is prevented. It is not expected to occur.

The three-dimensional thin-film porous structure of the cell structure disclosed in Korean Patent No. 1612500 exhibits excellent strength and stiffness characteristics, but even if the surface shape is curved, since it does not have an ideal TPMS shape, there is still room for improvement in terms of strength and stiffness. In addition, Korean Patent No. 1612500 has a simple process in manufacturing a sacrificial structure and advantageous for large structures, but in the case of applying and curing a liquid resin when manufacturing a sacrificial structure, the liquid resin itself is expensive and the sacrificial structure In the removal process, since the resin for forming the fillet, which has been etched and coated/cured on the beads, must be removed through separate steps, the process becomes complicated.

It is disclosed in Korean Patent No. 1905483 that the problem of Korean Patent No. 1612500 is improved. Korean Patent No. 1905483 is based on using a 3D structure in which beads are arranged as a sacrificial structure, as in Korean Patent No. 1612500, but at the same time, the surface of the 3D structure in which the beads are arranged is implemented in TPMS form. In the process, instead of applying and curing a separate liquid resin disclosed in Korean Patent No. 1612500, after partial dissolution on the entire surface of the beads itself, the flowable material of high viscosity generated in the process penetrates between the beads by capillary phenomenon. It discloses that a surface of TPMS or a similar type is formed through a method of curing by using a method. FIG. 4 is a two-dimensional schematic diagram of a process of connecting beads according to Korean Patent No. 1905483, and FIGS. 5, 6, and 7 each show an arrangement pattern of beads according to Comparative Examples and Examples of Korean Patent No. 1905483 with a cubic grid ( PC; primitive cubic), face centered cubic (FCC), and body centered cubic (BCC) in the state of showing the shape of the three-dimensional structure shown in stages of production.

Meanwhile, although it is known that at least 45 types of TPMS exist, including those shown in FIG. 3 ( http://facstaff.susqu.edu/brakke/evolver/examples/periodic/periodic.html ), Korean Patent No. 1905483 As an example, it is only specifically disclosed to fabricate a three-dimensional structure having three TPMS curved surfaces such as P, I-WP and F-RD, respectively, and three TPMS such as P, I-WP and F-RD The curved shape is based on PC, BCC and FCC of Figs. 5, 6 and 7, which are already well known as a kind of traditional solid atomic crystal structure. 8(a), (b), and (c) show the bead arrangement pattern for one layer of the three crystal lattice of PC, BCC, and FCC of FIGS. 5 to 7, respectively, but only the arrangement of beads of this pattern is P and I. -TPMS other than WP and F-RD cannot be implemented. Therefore, in order to develop a technology called “Shelluar” production of an ideal TPMS curved surface and related industrial fields by this, along with research in terms of realizing an ideal TPMS surface and securing mass production through process improvement, P, I-WP In addition to F-RD, there is a need to continuously expand the range through new research on how to specifically arrange beads in response to this for implementing various types of TPMS currently known.

Korean Patent No. 1612500 Korean Patent No. 1905483

-Seung Chul Han, Jeong Woo Lee, Kiju Kang, “A New Type of Low Density Material; Shellular”, Advanced Materials, Vol. 27, pp.5506-5511, 2015. -Gesammelte Mathematische Abhandlungen, Springer -M. Maldovan and E. L. Thomas, “Periodic Materials and Interference Lithography, 2009 WILEY-VCH Verlag GmbH & Co. KGaA, ISBN: 978-3-527-31999-2 -O. Al-Ketana, R. Rowshan, R.K.A. Al-Rub, Topology-mechanical property relationship of 3D printed strut, skeletal, and sheet based periodic metallic cellular materials. Additive Manufacturing, Vol. 19 (2018) pp.167-183.

It is an object of the present invention to provide a method for manufacturing a three-dimensional structure having a TPMS curved surface of other types in addition to the three known P, I-WP, F-RD, etc. through Korean Patent No. 1905483. Another object of the present invention is to provide a method for arranging beads accompanying such a method for manufacturing a three-dimensional structure, and a mechanical design used therein.

In the course of continuing research on how to specifically arrange beads for realizing various types of TPMS, in addition to P, I-WP, and F-RD, among the TPMS curves, D curve and N-14 The present invention has been reached by discovering the geometrical form of a new bead arrangement capable of implementing a curved surface and further specifying the design of a device required for this. The gist of the present invention regarding the recognition of the above-described problem and a solution based thereon is as follows.

(1) In a method for manufacturing a three-dimensional structure in which a plurality of beads are brought into contact with each other in a predetermined pattern to form an array of beads, and then the beads are interconnected, wherein the bead arrangement forms a reference layer pattern, and at least After contacting at least one sub-layer pattern, it is formed by bonding contact portions between the reference layer pattern and all beads constituting the sub-layer pattern, and the sub-layer pattern has the same or different projection surface pattern as the reference layer pattern. 3D structure manufacturing method, characterized in that.

(2) The method for manufacturing a three-dimensional structure of (1), wherein the reference layer pattern is disposed using a plate-shaped reference plate having a perforated portion having a diameter smaller than that of the bead to accommodate the bead.

(3) The method of manufacturing a three-dimensional structure of (2), characterized in that the perforated portions have different diameters.

(4) The perforated portions are formed alternately with two types of diameters, and when connecting the centers of the perforated portions, successive hexagonal array units are regularly formed, and the beads in the state of being completely accommodated in the perforated portions consist of two groups. The three-dimensional structure manufacturing method of (3), characterized in that the centers of the beads forming each group are placed on different planes.

(5) The method of manufacturing a three-dimensional structure of (2), wherein the perforated portions have the same diameter.

(6) When connecting the centers of the perforated portions, square array units spaced apart from each other are formed at equal intervals in all directions, and the beads in a state completely accommodated in the perforated portions form a group based on the square array units, and the center thereof is The three-dimensional structure manufacturing method of (5), characterized in that lying on the same plane and intersecting with each other.

(7) The reference layer pattern is a form in which successive hexagonal array units are regularly formed on a projection plane parallel to the layer when connecting the centers of the beads, and the beads forming the reference layer pattern form two groups, forming each group. The three-dimensional structure manufacturing method of (1), characterized in that the centers of the beads lie on different planes.

(8) The sub-layer pattern has the same projection surface pattern as the reference layer pattern, and three types of layer patterns are vertically stacked along the projection surface direction, but each layer pattern is cos19.5° of the bead diameter in one axis direction of the layer plane. The method for manufacturing a three-dimensional structure of (7), characterized in that relatively parallel movement and stacked.

(9) The reference layer pattern is a shape in which square array units spaced apart from each other are formed at equal intervals in all directions on a projection plane parallel to the layer when the centers of the beads are connected, and the beads forming the reference layer pattern form the square array units. The method of manufacturing a three-dimensional structure of (1), characterized in that they form a group based on a group and their centers are placed on the same plane and cross each other.

(10) The sub-layer pattern is vertically stacked in the direction of the projection surface at each of the upper and lower portions of the reference layer pattern, and consists of two types of a first sub-layer pattern and a second sub-layer pattern having a different projection surface pattern than the reference layer pattern. , The beads constituting the first sub-layer pattern are stacked so that their center is positioned at the center of the side between the square array units on the projection surface, and the beads constituting the second sub-layer pattern have a center on the projection surface. The three-dimensional structure manufacturing method of (9), characterized in that the stacked so as to be located in the center of the diagonal direction between the square array units.

According to the present invention, in addition to P, I-WP, and F-RD previously known through Korean Patent No. 1905483, other three-dimensional structures having a D-curved surface and an N-14 curved surface, and a three-dimensional thin-film porous structure using the same as a sacrificial structure Also, it can be manufactured to be mass-producible, so the technology related to the production of “Shelluar” of the ideal TPMS curved surface and its application range can be further expanded. In addition, the technical concept of the reference layer pattern and sub-layer pattern introduced for arranging beads when implementing the D and N-14 surfaces and the mechanical design of the reference plate used when forming the reference layer pattern are different TPMS. It is expected to be applicable when implementing a curved surface.

Figure 1 (a) is a three-dimensional structure arranged in beads according to Korean Patent No. 1612500, Figure 1 (b) is a structural diagram of a three-dimensional thin film porous structure manufactured using Figure 1 (a) as a sacrificial structure .
2 is a view illustrating a method of connecting beads arranged in a certain pattern with a separate liquid resin according to Korean Patent No. 1612500.
3 is a structural diagram of various types of TPMS (Triply Periodic Minimal Surface: 3-periodic minimal surface).
Figure 4 is a two-dimensional schematic diagram of the process of connecting beads according to Korean Patent No. 1905483.
5, 6, and 7 respectively show the arrangement pattern of beads according to Comparative Examples and Examples of Korean Patent No. 1905483 as a primitive cubic (PC), a face centered cubic (FCC), and a body centered cubic grid. (BCC; body centered cubic) the shape of the three-dimensional structure shown in stages of production.
Figure 8 (a), (b), (c) is the arrangement of beads for one layer of the three crystal lattice of PC, BCC, FCC of Figure 5, respectively.
9A and 9B are a plan view and a left view of a layer pattern for a bead used when implementing a D-type TPMS curved surface according to an embodiment of the present invention, and FIG. 9C is such a layer pattern formation. Reference plate for and its use state diagram.
10 and 11 are explanatory diagrams illustrating a process of laminating a layer pattern for beads in three dimensions to implement a D-type TPMS curved surface according to an embodiment of the present invention.
12 (a) and (b) are explanatory diagrams and real photographs of a manufacturing process of a three-dimensional structure having a D-type TPMS curved surface based on the arrangement of beads according to FIGS. 9 to 11.
13A is a photograph of an ideal D-type TPMS curved surface, and FIG. 13B is a CT image of a 3D structure having a D-type TPMS curved surface actually manufactured according to an embodiment of the present invention.
14A is a plan view of a reference layer pattern for a bead used when implementing an N-14 type TPMS curved surface according to an embodiment of the present invention, and FIGS. 14B and 14C are ( A plan view in a state in which sub-layer patterns of different shapes are stacked on top and bottom of the reference layer pattern of a).
FIG. 15A is a real photograph of the reference plate for forming the reference layer pattern of FIG. 14A, and FIG. 15B is a three-dimensional stacking of the reference layer pattern and the sub-layer pattern of FIG. 14 State diagram.
Figure 16 (a) is a real picture of the arrangement of beads used to implement the N-14 curved surface, Figure 16 (b) is the beads presented in Korean Patent No. 1905483 targeting the arrangement of beads in Figure 16 (a) A real photograph of a three-dimensional structure obtained by applying the connection method.
FIG. 17A is a photograph of an ideal N-14 type TPMS curved surface, and FIG. 17B is a CT image of a 3D structure having an N-14 type TPMS curved surface actually manufactured according to an embodiment of the present invention. Photo.

Hereinafter, the present invention will be described in detail through examples. Prior to this, terms or words used in the specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventors appropriately explain the concept of terms in order to explain their own invention in the best way. Based on the principle that it can be defined, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention. Therefore, the configuration of the embodiments described in the present specification is only one of the most preferred embodiments of the present invention, and does not represent all the technical spirit of the present invention, and various equivalents that can replace them at the time of filing of the present invention It is to be understood that there may be variations and variations. On the other hand, in the drawings, the same or similar reference numbers are given to the same or equivalent material, and in the entire specification, when a certain part "includes" a certain component, this is another component unless otherwise stated. It does not mean that other components may be further included.

The three-dimensional structure according to the present application is of a different type, but is implemented in the form of a three-periodic minimum curved surface or a form close thereto, as in Korean Patent No. 190283. In addition, such a three-dimensional structure may be particularly useful in manufacturing a three-dimensional thin film porous structure by using it as a template, that is, a sacrificial structure, but its use is not limited thereto. In this case, the three-dimensional thin film porous structure is a lightweight structure in which a certain unit cell composed of a thin film is periodically repeated, such as “shellular” described above.

In addition, the three-dimensional structure according to the present application is manufactured by contacting a plurality of beads in a predetermined pattern to form an array of beads, and then interconnecting the beads. In this case, the final connection between the beads may be a method of connecting with a separate liquid resin according to FIG. 2 and Korean Patent No. 1612500, but the beads themselves according to Korean Patent No. 1905483, which improves the problems of this connection method. A method of connecting the contact portions of the beads by partially dissolving the entire surface of the bead to form a fluid material may be applied more advantageously.

The present invention relates to the three-dimensional structure and the'bead arrangement' that is the basis for manufacturing a three-dimensional thin film porous structure using the same as a template, as disclosed in Korean Patent No. 1905483, TPMS of P, I-WP and F-RD. A concept of a'bead arrangement' different from the conventional general simple crystal lattice form according to FIG. 8, which was the basis for implementing a curved surface, is disclosed. That is, in the'bead arrangement' according to the present invention, after forming a reference layer pattern, contacting at least one sub-layer pattern above or below the reference layer pattern, all of the reference layer patterns and sub-layer patterns It is formed by bonding the contact portions between the beads, and the sub-layer pattern is characterized in that the sub-layer pattern has the same or different projection surface pattern as the reference layer pattern. In this case, the reference layer pattern may be disposed using a plate-shaped reference plate having a perforated portion having a diameter smaller than the diameter of the beads to accommodate the beads. On the other hand, in the embodiment, although the perforated portion is illustrated as a circle, it may have a polygonal shape or other shape limited to a size such that the spherical bead does not penetrate. Below, the process of implementing the D and N-14 curved surfaces in TPMS based on the concept of the base layer pattern and the sub-layer pattern for the arrangement of the beads and the mechanical design of the reference plate used when forming the reference layer pattern is described. The examples will be described in more detail.

First, FIGS. 9 to 13 are related to implementing a D-shaped curved surface among TPMS according to an embodiment of the present invention.

9A and 9B are a plan view and a left view of a layer pattern for a bead used when implementing a D-type TPMS curved surface according to an embodiment of the present invention, and FIG. 9C is such a layer pattern formation. It shows the reference plate for and its use state diagram. Specifically, (a) of FIG. 9 shows a plan view of one layer of an array of beads for making a D-shaped curved surface. In this layer, the beads are placed in succession with the center of which is located at the vertex of a hexagon and in contact with each other as a unit. Also in this case it not in the center of the bead surface is the same between adjacent, as shown in a left side view in accordance with the 9 (b) ^o 2rsin19.5 positioned alternately with the height difference of (where r is the radius of the bead). 9 (c) is a base plate designed for the purpose of arranging beads in a layer pattern according to FIGS. 9 (a) and (b). A number of perforated parts are perforated so that the center of the perforated part is located at a hexagonal vertex, but the size of the perforated parts alternately changes into two types. Specifically, the radius of the large perforated portion is 0.986r and the radius of the small perforated portion is 0.553r, and when the beads are arranged so that they are completely accommodated in the perforated portion, they will automatically contact each other and have different heights as shown in FIG. 9B. It is divided into bead groups and has a shape like a plan view as shown in (a) of FIG. 9. However, the size of the diameter of the bead is an example and may be formed in a different size depending on the cell size of the 3D structure to be implemented and the size of the related bead. In this state, adhesive or heat is applied to temporarily connect the contacts between the beads to form a single layer pattern.

10 and 11 are diagrams illustrating a process of laminating a layer pattern for beads in three dimensions to implement a D-type TPMS curved surface according to an embodiment of the present invention. Specifically, each of A, B, and C in FIG. 10 (a) shows one layer pattern arranged on the reference plate and connected to each other by the above method, and the A, B, and C layer patterns are in the y direction. It is a form of relatively parallel movement by cos19.5˚ of (2r). 10B is a perspective view and a projection view of a three-dimensional bead structure in which the layer patterns are repeatedly stacked in the order of A-B-C. FIG. 11 shows a method of contacting each other when forming a bead structure in FIG. 10(b) by repeatedly stacking the layer patterns A, B, and C of FIG. 10(a). That is, (a) of FIG. 11 is a layer pattern of B on the layer A pattern, (b) of FIG. 11 is a layer pattern of C on the layer pattern of B, and FIG. When the red colored marbles are in vertical contact with each other.

Referring back to FIGS. 9 to 11, in the arrangement of beads for the D-shaped curved surface, as shown in FIGS. 10A and 11, the middle reference layer pattern B is two sub-layers. It has the same projection surface pattern as the patterns A and C. When these reference layer patterns (B) and sub-layer patterns (A and C) are collectively referred to as a layer pattern, the beads constituting each of the layer patterns have their centers above and below each other as shown in FIG. 9B. It is divided into two groups lying on different planes. For the arrangement of these two groups of beads in the layer pattern, as shown in FIG. 9(c), the perforated portions of the reference plate are alternately formed with two types of diameters, and when connecting the centers of the perforated portions, Regular hexagonal array units are regularly formed, and the beads in the state of being completely accommodated in the perforated portion form two groups, and the centers of the beads forming each group are placed on different planes.

As a result, in the bead arrangement for the D-shaped curved surface, the reference layer pattern is a form in which consecutive regular hexagonal array units are regularly formed on a projection surface parallel to the layer when the center of the bead is connected, and the beads forming the reference layer pattern Silver is a group of two types, and the center of each bead is placed on a different plane. In addition, the sub-layer pattern has the same projection surface pattern as the reference layer pattern, and three types of layer patterns are vertically stacked along the projection surface direction, but each layer pattern is cos19.5˚ of the bead diameter (2r) in one axis direction of the layer plane. It can be seen that it is characterized by being stacked by being moved in parallel with each other.

12A and 12B show explanatory diagrams and real photographs of a manufacturing process of a 3D structure having a D-type TPMS curved surface based on the arrangement of beads according to FIGS. 9 to 11. Specifically, Figure 12 (a) is a target for the arrangement of beads of Figure 10 (b) (Figure 12 (a) left figure) as disclosed in Korean Patent No. 1905483 by partially dissolving the beads between the beads. It shows a 3D structure (Fig. 12 (a) left figure) with a D-type TPMS curved surface obtained by making a fillet connection and smoothing the surface and removing excess. 12(b) shows a real picture of a 3D structure actually fabricated by partially dissolving it by a chemical method using polymer beads.

FIG. 13A is a photograph of an ideal D-type TPMS curved surface, and FIG. 13B shows a CT image of a 3D structure having a D-type TPMS curved surface actually manufactured according to an embodiment of the present invention. Specifically, (a) of FIG. 13 shows the shape of the ideal D curved surface observed from various directions, and (b) of FIG. 13 is a CT (computer tomography) photograph of the three-dimensional structure of the polymer material of FIG. 12 (b). It can be seen that they are very similar to each other when comparing both of FIG. 13 (a) and FIG. 13 (b).

Next, FIGS. 14 to 17 are related to implementing an N-14 type curved surface in TPMS according to another embodiment of the present invention.

14A is a plan view of a reference layer pattern for a bead used when implementing an N-14 type TPMS curved surface according to an embodiment of the present invention, and FIGS. 14B and 14C are ( A plan view is shown in a state in which different types of first and second sub-layer patterns are stacked on top and bottom of the reference layer pattern of a). Specifically, FIG. 14 shows an arrangement of beads required to make an N-14 curved surface, of which (a) of FIG. 14 shows one basic reference layer pattern. In this basic layer pattern, the centers of the four marbles are located at the vertices of a square and are in contact with each other, and they are placed at regular intervals at regular intervals, that is, at equal intervals in all directions. 14B shows the additional arrangement of beads as a separate sub-layer pattern under the base layer pattern. In this case, the top and bottom of the beads constituting the square arrangement unit on the base layer pattern when viewed from the bottom toward the projection surface. It appears that there are additional marbles placed between the and left and right. When the separate layer pattern disposed under the base layer pattern is viewed as the first sub-layer pattern, the center of the beads constituting the first sub-layer pattern is the center of the side between the square array units of the base layer pattern on the projection surface. It can be seen as being stacked to be located at. 14(c) shows the additional arrangement of beads as a separate sub-layer pattern on the top of the base layer pattern, and in this case, the diagonal of the beads constituting the square arrangement unit on the base layer pattern when viewed from the top toward the projection surface It appears that there are additional marbles placed in the direction. When the separate layer pattern disposed above the base layer pattern is viewed as the second sub-layer pattern, the center of the beads constituting the second sub-layer pattern is in a diagonal direction between the square array units of the base layer pattern on the projection surface. It can be seen as being stacked to be located in the center.

FIG. 15A is a real photograph of the reference plate for forming the reference layer pattern of FIG. 14A, and FIG. 15B is a three-dimensional stacking of the reference layer pattern and the sub-layer pattern of FIG. 14 Show the state diagram. A number of perforated portions are formed, of which four perforated portions form one unit corresponding to the above-described square arrangement unit, and the four perforated portions constituting the unit are repeatedly formed by a predetermined distance in all directions. . In this case, the diameter of the perforated portion is the same, and the centers of all the beads accommodated in the reference plate to form the reference layer pattern have the same height, unlike the D-type reference layer pattern. On the other hand, the adhesion to the contact part between the beads in the N-14 type is one set of a reference layer pattern formed on a reference plate and a first sub-layer pattern attached to each other as shown in FIG. 15B. And, after forming a reference layer pattern on a reference plate, forming a second sub layer pattern, arranging and attaching the second sub layer pattern to another set, the reference layer pattern and the sub layer pattern set It may be a method of connecting the contact portions between the beads by stacking a plurality of them.

Referring back to FIGS. 14 and 15, in the arrangement of beads for the N-14 type curved surface, as shown in FIGS. 14A to 14C and 15B, the reference layer pattern (Fig. 14 (a)) is different from the two first and second sub-layer patterns (layer patterns excluding the corresponding beads in Fig. 14 (a) in Figs. 14 (b) and (c), respectively) It has a projection plane pattern. In this case, not only the centers of the beads constituting the first and second sub-layer patterns are located at the same height, but the center of the beads constituting the reference layer pattern is also at the same height, unlike the case of the D type. In response to this, when the perforated portions of the same diameter connect the centers of each other as shown in Fig. 15(b), square array units spaced apart from each other are formed at equal intervals in all directions, and are completely accommodated in the perforated portion. The marbles form a group based on the square array unit, and the centers of the beads are placed on the same plane and intertwine with each other (see FIGS. 14A and 15B).

As a result, in the bead arrangement for the N-14 type curved surface, the reference layer pattern is a form in which square array units spaced apart from each other are formed at equal intervals in all directions on a projection surface parallel to the layer when the centers of the beads are connected, and the The beads forming the reference layer pattern form a group based on the square arrangement unit, and the centers of the beads are placed on the same plane and intersect each other. In addition, the sub-layer pattern includes two types of first and second sub-layer patterns that are vertically stacked along a projection surface direction at each of the upper and lower portions of the reference layer pattern, and have a projection surface pattern different from the reference layer pattern, Beads constituting the first sub-layer pattern are stacked so that their centers are located at the centers of sides between the square array units on the projection surface, and the beads constituting the second sub-layer pattern have their centers on the projection surface. It can be seen that it is characterized in that it is stacked so as to be located in the center of the diagonal direction between the square array units.

Figure 16 (a) is a real picture of the arrangement of beads used to implement the N-14 curved surface, Figure 16 (b) is the beads presented in Korean Patent No. 1905483 targeting the arrangement of beads in Figure 16 (a) A real photograph of a three-dimensional structure obtained by applying the connection method is shown. Specifically, FIG. 16(a) shows that the contact part between the beads arranged in the above method is fixed, and FIG. 16(b) shows that FIG. 16(a) is partially dissolved as disclosed in Korean Patent No. 1905483. It shows the shape of a three-dimensional structure with N-14 curved surfaces obtained by making connections, smoothing the surface, and removing excess.

FIG. 17A is a photograph of an ideal N-14 type TPMS curved surface, and FIG. 17B is a CT image of a 3D structure having an N-14 type TPMS curved surface actually manufactured according to an embodiment of the present invention. Show the picture. Specifically, Figure 17 (a) is a perspective view of the N-14 curved surface, Figure 17 (b) is obtained by CT (Computed Tomography) imaging of the polymer three-dimensional structure of Figure 16 (b), Figure 17 ( It can be seen that a) and FIG. 17(b) are similar to each other.

As described above, according to the present invention, in addition to P, I-WP and F-RD previously known through Korean Patent No. 1905483, other three-dimensional structures having a D-curve and N-14 curved surface, and a three-dimensional sacrificial structure Since thin-film porous structures can also be mass-produced, technology related to the production of “Shelluar” of ideal TPMS curved surface and its application range can be further expanded. Specifically, it has been reported that shellular with D curved surface has high strength when subjected to compressive load (O. Al-Ketana, R. Rowshan, RKA Al-Rub, Topology-mechanical property relationship of 3D printed strut, skeletal, and sheet based periodic metallic cellular materials.Additive Manufacturing, Vol. 19 (2018) pp.167-183.). Since the N-14 curved surface has a large area per unit volume, the Shellular is an interface between two sub-volumes and can be efficiently used for the transfer of heat, substances, ions, etc. A type of boiler or shellular that is contained and heat is applied to the remaining subspaces, and one subspace is a cell culture place, and the remaining subspace is a tissue engineering scaffold or shellular that flows fluid containing nutrients and oxygen. It is an electrolyte membrane and can be used for fuel cells in which oxygen in one sub-space and hydrogen flow in the other sub-space. In addition, the technical concept of the reference layer pattern and sub-layer pattern introduced for arranging beads when implementing the D and N-14 surfaces and the mechanical design of the reference plate used when forming the reference layer pattern are different TPMS. It is expected to be applicable when implementing a curved surface.

The above description relates to specific embodiments of the present invention. The above embodiments according to the present invention are not understood as limiting the disclosed matters or the scope of the present invention for the purpose of explanation, and various changes and modifications without departing from the essence of the present invention are those of ordinary skill in the art. It should be understood that this is possible, and all such modifications and changes may be understood to correspond to the scope of the invention disclosed in the claims or equivalents thereof.

Claims (10)

In the method of manufacturing a three-dimensional structure for interconnecting the beads after forming an array of beads by contacting a plurality of beads in a predetermined pattern,
The bead arrangement is formed by forming a reference layer pattern, contacting at least one sub-layer pattern above or below the reference layer pattern, and then bonding contact portions between all beads constituting the reference layer pattern and the sub-layer pattern. ,
The method of manufacturing a 3D structure, wherein the sub-layer pattern has the same or different projection surface pattern as the reference layer pattern.
The method of claim 1, wherein the reference layer pattern is disposed using a plate-shaped reference plate having a perforated portion having a diameter smaller than that of the beads to accommodate the beads.
The method of claim 2, wherein the perforated portions have different diameters.
The method of claim 3, wherein the perforated portions are alternately formed with two kinds of diameters, and when connecting the centers of the perforated portions, consecutive regular hexagonal array units are regularly formed, and two kinds of beads are completely accommodated in the perforated portion. A method for manufacturing a three-dimensional structure, characterized in that the centers of the beads forming a group of and each group are placed on different planes.
The method of claim 2, wherein the perforated portions have the same diameter.
The method of claim 5, wherein when connecting the centers of the perforated portions, square array units spaced apart from each other are formed at equal intervals in all directions, and beads in a state completely accommodated in the perforated portions form a group based on the square array units, and The three-dimensional structure manufacturing method, characterized in that the center is placed on the same plane and intersected with each other.
The method of claim 1, wherein the reference layer pattern is a form in which consecutive regular hexagonal array units are regularly formed on a projection plane parallel to the layer when the centers of the beads are connected, and the beads forming the reference layer pattern form two groups and each The three-dimensional structure manufacturing method, characterized in that the centers of the beads forming the group lie on different planes.
The method of claim 7, wherein the sub-layer pattern has the same projection surface pattern as the reference layer pattern, and three types of layer patterns are vertically stacked along a projection surface direction, and each layer pattern has a bead diameter cos19 in a direction of one axis of the layer plane. 3D structure manufacturing method, characterized in that the relatively parallel movement by 5˚ stacked.
The method of claim 1, wherein the reference layer pattern is a shape in which square array units spaced apart from each other on a projection plane parallel to the layer are formed at equal intervals in all directions when the centers of the beads are connected, and the beads forming the reference layer pattern are A method for manufacturing a three-dimensional structure, characterized in that a group is formed based on an array unit and its center is placed on the same plane and intersected with each other.
10. The method of claim 9, wherein the sub-layer pattern is vertically stacked along a projection plane direction at each of the upper and lower portions of the reference layer pattern, and two types of a first sub-layer pattern and a second sub-layer pattern having a different projection plane pattern than the reference layer pattern. And the beads constituting the first sub-layer pattern are stacked so that their center is located at the center of the sides between the square array units on the projection surface, and the beads constituting the second sub-layer pattern have a center thereof. 3D structure manufacturing method, characterized in that stacked on the projection surface so as to be located at the center of the diagonal direction between the square array units.

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