Metamaterial manufacturing method, coating device, metamaterial manufacturing system, metamaterial, and article made of metamaterial

Abstract

The purpose of the present disclosure is to provide a metamaterial manufacturing method, a coating device, a metamaterial manufacturing system, a metamaterial, and an article made of a metamaterial with which it is possible to increase the film thickness of a metamaterial without deteriorating characteristics of a metamaterial.　The present disclosure is a metamaterial manufacturing method that is executed by a metamaterial manufacturing system comprising a coating device 92 and a separation device 93. The metamaterial manufacturing method comprises: a first step in which the coating device 92 dip-coats a non-conductive layer 13 on a non-conductive film 11 in which a conductor layer 12 having a meta-atom shape is formed; and a second step in which the separation device 93 separates the non-conductive film 102 coated with the non-conductive layer 13 into a metamaterial that includes at least one meta-atom.

Description

Metamaterial manufacturing method, coating device, metamaterial manufacturing system, and metamaterial and article thereof

[0001] The present disclosure relates to a method for producing a metamaterial, a coating apparatus, a metamaterial production system, and a metamaterial and an article thereof.

[0002] Artificial structures (hereafter referred to as metamaterials) that have properties different from those of natural materials have been proposed. Metamaterials and metaatoms have a relationship similar to that between the bulk of matter and the atoms that make it up. Metaatoms are the unit structures that make up metamaterials.

[0003] Metamaterials that have been fabricated so far include a metamaterial in which a split-ring resonator is fabricated on a resin wall surface (see, for example, Non-Patent Document 1), and a multilayer metamaterial (see, for example, Non-Patent Document 2).

[0004] D. Bruce et al. adv. mater, 22, 5053-5057, 2010N. Liu et al. nature. mater, 7 31-37, 2008

[0005] However, the metamaterial of Non-Patent Document 1 had a limit to the thickness that could be produced. The metamaterial of Non-Patent Document 2 could be made thicker by using multiple layers, but there was a possibility that a refractive index difference would occur at the interfaces between the layers. In order to improve the properties of metamaterials, such as transmittance, optical activity, and directivity, it is desirable to have as few interfaces where a refractive index difference could occur.

[0006] Therefore, an object of the present disclosure is to provide a metamaterial manufacturing method, a coating device, a metamaterial manufacturing system, and a metamaterial and article thereof that can increase the film thickness of a metamaterial without degrading the properties of the metamaterial.

[0007] The inventors have invented a method for fabricating metamaterials that reduces the number of interfaces where refractive index differences can occur.

[0008] The method for producing a metamaterial of the present disclosure includes a first step of dip-coating a non-conductive layer onto a non-conductive film on which a conductive layer having the shape of a meta-atom has been formed, and a second step of separating the non-conductive film coated with the non-conductive layer into metamaterials containing at least one meta-atom.

[0009] The method may further include a third step of individually heating and shaping the metamaterial obtained in the second step.

[0010] A fourth step of forming a conductive layer having the shape of the meta-atom on a non-conductive film may be carried out before the first step.

[0011] When separating metamaterials containing at least one meta-atom using dicing, noise components may be generated due to residual dicing tape. Therefore, this disclosure proposes two methods that do not use dicing in the second step. The first method performs the separation by thermally imprinting the non-conductive film coated with the non-conductive layer in a shape corresponding to the shape of the metamaterial. The second method performs the separation by cutting out the non-conductive film coated with the non-conductive layer in a shape corresponding to the shape of the metamaterial.

[0012] The coating apparatus of the present disclosure is a dip-coating apparatus that dip-coats a non-conductive layer onto a non-conductive film on which a conductive layer having a meta-atom shape is formed. In the coating apparatus of the present disclosure, the non-conductive film may have a rectangular shape.

[0013] The metamaterial production system of the present disclosure comprises: a coating apparatus of the present disclosure; and a separation apparatus that separates the non-conductive film coated with a non-conductive layer in the coating apparatus into metamaterials each having a shape corresponding to the shape of the metamaterial and including at least one meta-atom.

[0014] The metamaterial production system of the present disclosure may further include a heating device that individually heats and shapes the metamaterial obtained by the separation.

[0015] The metamaterial production system of the present disclosure may further include a meta-atom formation device that forms a conductive layer having the shape of the meta-atom on a non-conductive film.

[0016] The metamaterial of the present disclosure is a metamaterial that can be produced using the metamaterial production method of the present disclosure, and can also be obtained by using the coating apparatus of the present disclosure.

[0017] Specifically, the metamaterial of the present disclosure comprises: a non-conductive film; at least one conductive layer disposed on the non-conductive film and having the shape of a meta-atom; and a non-conductive layer disposed on the non-conductive film and the conductive layer, the non-conductive layer having a thickness greater than that of the conductive layer.

[0018] One aspect of the present disclosure may be an article comprising the metamaterial of the present disclosure.

[0019] The above disclosures can be combined as much as possible.

[0020] According to the present disclosure, it is possible to provide a metamaterial manufacturing method, a coating device, a metamaterial manufacturing system, and a metamaterial and article thereof, which are capable of increasing the film thickness of a metamaterial without degrading the properties of the metamaterial.

[0021] 1 is an example embodiment of a metamaterial production system according to the present disclosure; FIG. 2 is an example embodiment of a production method according to the present disclosure; FIG. 3 is an explanatory diagram of a metamaterial produced using the production method according to the present disclosure; FIG. 4 is an explanatory diagram of a metamaterial produced using a conventional production method; FIG. 5 is an example embodiment of a production method according to the present disclosure; FIG. 6 is an example embodiment of a production method according to the present disclosure; FIG. 7 is an example embodiment of a production method according to the present disclosure;

[0022] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below. These implementation examples are merely illustrative, and the present disclosure can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. Note that components with the same reference numerals in this specification and drawings indicate the same components.

[0023] First Embodiment Fig. 1 shows an example embodiment of a metamaterial production system according to the present disclosure. A metamaterial production system 90 according to the present embodiment includes a coating device 92 and a separation device 93, and performs the production method according to the present disclosure. Fig. 1 shows an example in which the metamaterial production system 90 further includes a meta-atom formation device 91 and a heating device 94.

[0024] An embodiment of the manufacturing method of the present disclosure is shown in Figure 2. As shown in Figure 2(a), a metamaterial-containing film 101 of this embodiment is made of a resin film 11 and a conductive layer 12 provided on the resin film 11. The manufacturing method of this embodiment includes a first step (Figure 2(b)) in which a coating device 92 coats a resin layer 13 on the side of the metamaterial-containing film 101 where the conductive layer 12 is provided, thereby producing a metamaterial-containing film 102, and a second step (Figure 2(c)) in which a separation device 93 separates the metamaterial-containing film 102 into metamaterials each containing at least one meta-atom, thereby producing a metamaterial 103.

[0025] In this embodiment, the resin film 11 is not limited to a resin, but may be a non-conductive film made of any non-conductive material that can transmit a desired frequency band, such as the terahertz band. The resin layer 13 may be a non-conductive layer made of any non-conductive material that can transmit a desired frequency band, such as the terahertz band. The refractive index of the resin layer 13 with respect to the target terahertz wave may be the same as or different from that of the resin film 11. For example, the resin layer 13 may be of the same type as the resin film 11.

[0026] In this embodiment, the conductive layer 12 is any conductive material capable of forming meta-atoms, and examples thereof include metal materials such as Au, and semiconductors such as graphite and silicon carbide.

[0027] The coating device 92 uses dip coating, which coats the metamaterial-containing film 101 with the resin layer 13 by immersing it in a resin solution. Therefore, any resin that can be dip coated can be used for the resin layer 13. Examples of such resins include cycloolefin polymer (COC / COP), polyethylene (PE), polymethylpentene (PMP), Teflon (registered trademark) (PTFE), polycarbonate (PC), polypropylene (PP), acrylic resin (PMMA), ABS resin, and combinations thereof.

[0028] The coating device 92 coats the resin layer 13 to a desired thickness. For example, the thickness of the resin layer 13 is greater than that of the conductor layer 12. The thickness of the resin layer 13 may be equal to or greater than that of the resin film 11. For example, the resin film 11 and the resin layer 13 may be made to have the same thickness so that the meta-atom is cubic and the conductor layer 12 is formed at the center of the meta-atom. The resin layer 13 may be 1.5 times or twice as thick as the resin film 11.

[0029] 3 shows an example of a metamaterial 103 manufactured by the manufacturing method of this embodiment. The metamaterial 103 of this embodiment includes a resin film 11, a conductor layer 12 formed on the resin film 11, and a resin layer 13 covering the conductor layer 12. The conductor layer 12 is disposed on the resin film 11 and has the shape of a meta-atom. In this embodiment, the resin layer 13 is thick-film coated on the resin film 11 and the conductor layer 12. Therefore, the refractive index of the resin film 11 is n １ and the refractive index of the resin layer 13 is n ２ When n １ / n ２ An interface of

[0030] In contrast, when dip coating as in the conventional example is not used, as shown in Figure 4, it is necessary to coat the periphery of the conductor layer 112 on the resin film 111A with a resin layer 113, and then bond the resin film 111B to the resin film 111A. １ and the refractive index of the resin layer 113 is n ３ and the refractive index of the resin film 111B is n ２ When １ / n ３ The interface and n ３ / n ２ Furthermore, if thermocompression bonding is used for bonding, there is a possibility that an air layer will be included in the boundary between resin layer 113 and resin film 111B.

[0031] In this embodiment, the coating device 92 performs thick film coating using dip coating in the first step, eliminating the need to bond the resin film 111B. Furthermore, the dip coating performed by the coating device 92 is a process that prevents an air layer from entering the boundary between the metamaterial-containing film 101 and the resin layer 13. Therefore, in this embodiment, by reducing the number of interfaces in the metamaterial structure and preventing the intrusion of an air layer, the number of interfaces of the metamaterial can be reduced overall, thereby improving the properties of the metamaterial.

[0032] Furthermore, the resin film 11 on which the coating device 92 applies thick coating may be circular or rectangular. The rectangular shape of the resin film 11 increases the collection rate per batch and reduces the occurrence of uneven dip coating compared to wafers. This improves the yield when applying thick coating to the resin layer 13.

[0033] Second Embodiment Figure 5 shows an example of the second step performed by the separating apparatus 93 shown in Figure 1. As shown in Figure 5(a), the metamaterial-containing film 102 includes conductive layers 12 that become meta-atoms at predetermined intervals. The separating apparatus 93 performs thermal imprinting on the metamaterial-containing film 102 (Figure 5(a)) using a mold 81 shaped according to the shape of the metamaterial at predetermined intervals of the meta-atoms (Figure 5(b)), forming recesses 82 in the metamaterial-containing film 102 (Figure 5(c)), and separating the metamaterial-containing film 102 along the recesses 82 by applying force from both sides of the metamaterial-containing film 102 using a pressure roller or the like (Figure 5(d)). This separates the metamaterial-containing film 102 into metamaterials each containing at least one meta-atom, generating the metamaterial 103.

[0034] The separating device 93 of this embodiment can separate the metamaterial-containing film 102 into metamaterials 103 without using dicing. This makes it possible to remove noise components due to remaining dicing tape. Furthermore, by setting the shape of the mold 81, it is possible to manufacture metamaterials 103 of various shapes. In other words, this embodiment allows the shape of the resin powder in which meta-atoms are embedded to be any shape.

[0035] Third Embodiment Figure 6 shows an example of the second step performed by the separating device 93 shown in Figure 1. The separating device 93 heats the metamaterial-containing film 102 formed in the coating device 92 to a temperature equal to or higher than the softening point of the resin film 11 and resin layer 13 that make up the metamaterial-containing film 102 (Figure 6(a)). The separating device 93 then presses the metamaterial-containing film 102 against a heated metal molded plate 83 that is arranged with a predetermined gap or holes (Figure 6(b)). This melts the metamaterial-containing film 102, and the molten and hardened metamaterial that hangs down from the gap or hole in the metal molded plate 83 (Figure 6(c)). The cutting blade 84 is then used to cut the extracted metamaterial from the metamaterial-containing film 102 in a direction perpendicular to the hanging metamaterial (Figure 6(d)). This separates the metamaterial-containing film 102 into metamaterials containing at least one meta-atom, producing the metamaterial 103.

[0036] The separating device 93 of this embodiment can separate the metamaterial-containing film 102 into metamaterials 103 without using dicing. This makes it possible to remove noise components due to remaining dicing tape. Furthermore, by setting the shape of the metal molded plate 83, it is possible to manufacture metamaterials 103 of various shapes. In other words, this embodiment allows the shape of the resin powder in which meta-atoms are embedded to be any shape.

[0037] Fourth Embodiment The manufacturing method of this embodiment may include a third step performed by a heating device 94 shown in Fig. 1 after the second step performed by the separation device 93 shown in Fig. 1. The heating device 94 individually heats and shapes the metamaterial 103 obtained in the second step.

[0038] 7 shows an example of the third step performed by the heating device 94. The heating device 94 heats the metamaterials 103 one by one while dropping the metamaterials 103 one by one inside the tube 86. Any means capable of softening the surfaces of the resin film 11 and the resin layer 13 can be used for heating, and a burner 85 can be exemplified.

[0039] The heating device 94 heats the resin film 11 and the resin layer 13 to a temperature equal to or higher than their softening points, thereby deforming and shaping them into a rounded metamaterial 103. The metamaterial 103 can be made spherical by adjusting the heating time and heating temperature in the heating device 94. That is, in this embodiment, the resin powder in which meta-atoms are embedded can be made spherical.

[0040] Fifth Embodiment The manufacturing method of this embodiment may include a fourth step performed by a meta-atom formation device 91 shown in FIG. 1 before the first step of producing the metamaterial-containing film 102. The meta-atom formation device 91 forms a conductor layer 12 having the shape of a meta-atom on a resin film 11, thereby producing the metamaterial-containing film 101. In this embodiment, the shape of the meta-atom is arbitrary, and an example is a split ring resonator with a ring width of 1 μm or more and an average radius of 1 to 500 μm.

[0041] Figure 8 shows an example of the fourth step performed by the meta-atom formation device 91. The meta-atom formation device 91 forms a conductor layer 12 over the entire resin film 11 (Figure 8(b)), applies a photoresist 21 on the upper surface of the conductor layer 12 (Figure 8(c)), irradiates the photoresist 21 with ultraviolet light shaped like a meta-atom using a photomask 22 (Figure 8(d)), develops the photoresist 21 (Figure 8(e)), and performs etching (Figure 8(f)). This allows the production of a metamaterial-containing film 101 in which a conductor layer 12 shaped like a meta-atom is formed on the resin film 11.

[0042] As described above, the manufacturing method and metamaterial manufacturing system of the present disclosure include the coating apparatus 92 of the present disclosure, and therefore can manufacture a metamaterial 103 with a reduced number of interfaces to one. Therefore, by using the manufacturing method of the present disclosure, it is possible to manufacture a metamaterial with improved properties such as transmittance, optical activity, and directionality in a desired frequency band such as the terahertz band.

[0043] Furthermore, the manufacturing method and metamaterial production system of the present disclosure include the separation device 93 of the present disclosure, and therefore the shape of the resin powder in which meta-atoms are embedded can be made into any shape. Furthermore, the manufacturing method and metamaterial production system of the present disclosure include the heating device 94 of the present disclosure, and therefore the resin powder in which meta-atoms are embedded can be made spherical. In this way, the manufacturing method and metamaterial production system of the present disclosure can accommodate shapes other than a cubic structure, and therefore the meta-atom content can be increased in an article comprising the metamaterial 103.

[0044] 11, 111A, 111B: Resin film 12, 112: Conductor layer 13, 113: Resin layer 21: Photoresist 22: Photomask 81: Mold 82: Recess 83: Metal molded plate 84: Cutting blade 85: Burner 86: Tube 90: Metamaterial production system 91: Metaatom formation device 92: Coating device 93: Separation device 94: Heating device 101, 102: Metamaterial-containing film 103, 1103: Metamaterial

Claims

1. A method for producing a metamaterial, comprising: a first step of dip-coating a non-conductive layer onto a non-conductive film on which a conductive layer having the shape of a meta-atom has been formed; and a second step of separating the non-conductive film coated with the non-conductive layer into metamaterials containing at least one meta-atom.

2. The method for producing a metamaterial according to claim 1, further comprising a third step of individually heating and shaping the metamaterial obtained in the second step.

3. The method for producing a metamaterial according to claim 1, wherein in the second step, the separation is performed by thermally imprinting the non-conductive film coated with the non-conductive layer in a shape corresponding to the shape of the metamaterial.

4. The method for producing a metamaterial according to claim 1, wherein in the second step, the separation is carried out by cutting out the non-conductive film coated with the non-conductive layer into a shape corresponding to the shape of the metamaterial.

5. The method for producing a metamaterial according to claim 1, further comprising a fourth step, prior to the first step, of forming a conductive layer having the shape of the meta-atom on a non-conductive film.

6. A coating device for dip-coating a non-conductive layer onto a non-conductive film on which a conductive layer having a meta-atom shape has been formed.

7. The coating apparatus according to claim 6, wherein the non-conductive film is rectangular in shape.

8. A metamaterial production system comprising: a coating apparatus according to claim 6 or 7; and a separation apparatus that separates a non-conductive film coated with a non-conductive layer in the coating apparatus into metamaterials each containing at least one meta-atom in a shape corresponding to the shape of the metamaterial.

9. The metamaterial production system according to claim 8, further comprising a heating device that individually heats and shapes the metamaterial obtained by the separation.

10. The metamaterial production system according to claim 8, further comprising a meta-atom formation device that forms a conductive layer having the shape of the meta-atom on a non-conductive film.

11. A metamaterial comprising: a non-conductive film; at least one conductive layer disposed on the non-conductive film and having the shape of a meta-atom; and a non-conductive layer disposed on the non-conductive film and the conductive layer, the non-conductive layer having a thickness greater than that of the conductive layer.

12. An article comprising the metamaterial of claim 11.

Images