Anisotropic nanoparticle intaglio transfer method, and flexible electrode manufactured using same

Abstract

According to one aspect of the present invention, an intaglio transfer method is provided, the method comprising the steps of: (S100) applying a nanowire material to a stamp; (S200) bringing the stamp into contact with a pattern-formed intaglio trench and separating same so as to transfer the pattern formed of the nanowire material to the stamp; and (S300) bringing the pattern-transferred stamp into contact with a substrate and separating same so as to transfer the pattern formed of the nanowire material to the substrate.

Description

Method for negative transfer of anisotropic nanoparticles and flexible electrode manufactured thereby

[0001] The present invention relates to a method for negative transfer of anisotropic nanoparticles and a flexible electrode manufactured thereby, and more specifically, to a method for negative transfer using nanowires and a flexible electrode manufactured thereby.

[0002] Silver nanowires form a conductive network due to their high conductivity and high aspect ratio when deformed.

[0003] Flexible electrodes based on these silver nanowires can be used in healthcare systems, displays, sensors, energy, and soft robotics.

[0004] However, this requires high-resolution patterning technology for integration, miniaturization, and functional advancement.

[0005] Looking at the trends in silver nanowire patterning technology according to conventional technology, there are photolithography, laser patterning, vacuum filtration, inkjet printing, and dry transfer printing.

[0006] A dry transfer printing method according to the prior art is illustrated in Fig. 1.

[0007] Referring to Figure 1, a conventional dry transfer printing method includes steps of contacting and picking up a target material via a stamp, contacting the target material with a desired substrate, and transferring the target material to the final substrate. This method provides advantages such as easy and fast processing, repeatability, a wide range of final substrate materials, and the absence of chemical damage from the dry method.

[0008] However, referring to Fig. 2, it can be seen that the conventional dry transfer printing method has a problem of low resolution at the edge of the pattern.

[0009] One object of the present invention is to improve the low resolution of the pattern edge in a conventional dry transfer printing method.

[0010] According to one aspect of the present invention, a method for transferring an intaglio material is provided, comprising: a step of applying a nanowire material to a stamp (S100); a step of bringing the stamp into contact with an intaglio trench in which a pattern is formed and separating the stamp to transfer a pattern formed of a nanowire material to the stamp (S200); and a step of bringing the stamp with the pattern transferred thereto into contact with a substrate and separating the stamp to transfer a pattern formed of a nanowire material to the substrate (S300).

[0011] According to another aspect of the present invention, a flexible electrode manufactured by the above-described intaglio transfer method is provided.

[0012] According to the present invention, a dry transfer printing method capable of obtaining high resolution even at the edge of a pattern can be provided.

[0013] According to the present invention, a flexible electrode having various high-resolution patterns can be manufactured.

[0014] Figure 1 is a schematic diagram showing a dry transfer printing process according to a conventional technology.

[0015] Figure 2 shows the low resolution of the dry transfer printing process according to the prior art.

[0016] Figure 3 is a schematic diagram showing an intaglio transfer method according to one embodiment of the present invention.

[0017] Figure 4 shows a printing mechanism of an intaglio transfer method according to one embodiment of the present invention.

[0018] Figure 5 shows a photograph of a nanowire film broken according to the method illustrated in Figure 4.

[0019] Figure 6 shows patterning of silver nanowires according to one embodiment of the present invention.

[0020] Figure 7 shows that patterning of CdS inorganic nanowires according to one embodiment of the present invention is implemented with various aspect ratios.

[0021] Figure 8 shows a flexible electrode according to one embodiment of the present invention.

[0022] Figure 9 shows a flexible electrode application according to one embodiment of the present invention.

[0023] The above objectives, other objectives, features, and advantages will be readily understood through the following preferred embodiments, illustrated in the accompanying drawings. However, the embodiments described herein are not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete, and to sufficiently convey the technical concepts to those skilled in the art.

[0024] In describing each drawing, similar reference numerals are used to designate similar components. In the attached drawings, the dimensions of structures are shown exaggerated for clarity of the present invention. Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only to distinguish one component from another. For example, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component, without departing from the scope of the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise.

[0025] In this specification, it should be understood that terms such as "include" or "have" are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof. In addition, when it is said that a part such as a layer, film, region or plate is "on" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when it is said that a part such as a layer, film, region or plate is "under" another part, this includes not only the case where it is "directly below" the other part, but also the case where there is another part in between.

[0026]

[0027] Figure 3 is a schematic diagram showing an intaglio transfer method according to one embodiment of the present invention.

[0028]

[0029] Referring to FIG. 3, an intaglio transfer method according to an embodiment of the present invention includes a step of applying a nanowire material to a stamp (S100); a step of bringing the stamp into contact with an intaglio trench in which a pattern is formed and separating the stamp to transfer a pattern formed of a nanowire material to the stamp (S200); and a step of bringing the stamp with the pattern transferred thereto into contact with a substrate and separating the stamp to transfer a pattern formed of a nanowire material to the substrate (S300).

[0030]

[0031]

[0032] The step (S100) of applying a nanowire material to a stamp may be to pick up nanowires that have formed a network using a stamp with a flat surface.

[0033]

[0034] In one embodiment, the stamp used may be an elastic polymer such as PDMS.

[0035]

[0036] The nanowire material may be an anisotropic nanomaterial. In one embodiment, the anisotropic nanomaterial may be a silver (Ag) nanowire having an aspect ratio of 1000. In another embodiment, the anisotropic nanomaterial may be an inorganic material. Here, the inorganic material may be a metal chalcogenide. Preferably, the metal chalcogenide may be selected from the group consisting of CdS, CdSe, WS2, and MoS2.

[0037]

[0038] In the step (S200) of contacting the stamp with a patterned engraved trench and separating the stamp to transfer a pattern formed of a nanowire material to the stamp, when the nanowire on the stamp comes into contact with the trench and is transferred to the part where it touches the trench by a strong force, a nanowire having a pattern of a desired shape can be left on the stamp.

[0039]

[0040] The negative trench used may be composed of a material having a surface energy greater than that of the stamp. In one embodiment, the negative trench may be composed of a material having a surface energy greater than that of the PDMS stamp.

[0041]

[0042] In one embodiment, the negative trench may be a silicon substrate patterned using AZ5214 material among negative photoresists to represent a high-resolution pattern.

[0043]

[0044] In the step (S300) of transferring a pattern formed of a nanowire material to the substrate by contacting and separating the stamp on which the above pattern has been transferred to the substrate, the nanowires patterned on the stamp can be transferred by contacting the desired (final) substrate.

[0045]

[0046] In one embodiment, the substrate may be composed of a material having a surface energy greater than that of the PDMS stamp. For example, the substrate may be composed of a variety of substrates, including flexible substrates such as glass, silicon, and PET.

[0047]

[0048] Fig. 4 illustrates a printing mechanism of an intaglio transfer method according to one embodiment of the present invention. Fig. 5 illustrates a photograph of a nanowire film broken according to the method illustrated in Fig. 4.

[0049]

[0050] Referring to Figure 4, it can be seen that a force is applied when a stamp with a silver nanowire film attached is brought into contact with the engraved trench. In the case of one-dimensional nanowires, since they have an anisotropic shape, a large force may be required to break them depending on the pattern shape during pattern formation. In one embodiment, 600 g / cm 2 By applying the above force, a pattern can be formed.

[0051]

[0052] Referring to Figure 5, it can be seen that the fracture result of the silver nanowire film is a fracture that occurs in a vertical, nearly straight line.

[0053]

[0054] Figure 6 shows patterning of silver nanowires according to one embodiment of the present invention.

[0055]

[0056] Referring to FIG. 6, it can be seen that, according to one embodiment of the present invention, high-resolution patterning of silver nanowires with a high aspect ratio is possible. That is, it can be seen that, using silver nanowires with an aspect ratio (L / D) of 1000, resolutions of 50 μm and 7 μm can be obtained in the implementation example.

[0057]

[0058] Table 1 below provides data comparing the intaglio transfer method of the present invention with a patterning method according to a conventional technology.

[0059]

[0060] Patterning method Nanowire size aspect ratio (L / D) Pattern resolution Dry transfer printing using a structured stamp D = 75 nm, L = 12.5 ㎛ ~ 1671 mm Vacuum filtration D = 70 nm, L = 60 ㎛ ~ 85 7250 ㎛ Vacuum filtration using screen printing D = 35 ~ 50 nm, L = 20 ~ 30 ㎛ ~ 57 1 ~ 60 050 ㎛ Direct printing technique D = 23 nm, L = 17 ㎛ ~ 73 950 ㎛ Electrohydrodynamic printing technique D = ~ 120 nm, L = ~ 25 ㎛ ~ 20 845 ㎛ The present invention (engraving transfer method) D = 21 nm, L = 21 ㎛ ~ 100 07 ㎛

[0061]

[0062] As can be seen from Table 1 above, according to the intaglio transfer method of the present invention, the aspect ratio (L / D) can reach up to 1000 and the pattern resolution can reach up to 7 ㎛. It can be seen that this is an excellent aspect ratio and pattern resolution compared to conventional patterning methods.

[0063]

[0064] Figure 7 shows that patterning of CdS inorganic nanowires according to one embodiment of the present invention is implemented with various aspect ratios.

[0065]

[0066] Referring to Figure 7, the circular pattern represents the desired pattern, and the materials used in the pattern are enlarged and displayed within the red box. Comparing the materials within the red box reveals that they have various aspect ratios. The fact that all circular patterns are identical demonstrates that nanomaterials with different aspect ratios were successfully patterned into the desired pattern at high resolution.

[0067]

[0068] Also, referring to the second row of the photo in Figure 7, the edge of the circular pattern is enlarged and displayed. This shows that as the aspect ratio increases, the materials constituting the pattern become less dense, resulting in greater flexibility. This also demonstrates that high-resolution pattern formation is possible even with an increasing aspect ratio.

[0069]

[0070] Fig. 8 shows a flexible electrode according to one embodiment of the present invention. Fig. 9 shows a flexible electrode application according to one embodiment of the present invention.

[0071]

[0072] Referring to FIG. 8, it can be seen that, according to one embodiment of the present invention, a flexible electrode having various patterns with high resolution can be manufactured.

[0073]

[0074] Referring to FIG. 9, it can be seen that, according to one embodiment of the present invention, a flexible and bendable electrode can be manufactured by using nanowires.

Claims

1. Step of applying nanowire material to a stamp (S100); A step (S200) of transferring a pattern formed of a nanowire material to the stamp by contacting and separating the stamp from the negative trench where the pattern is formed; and Step (S300) of contacting and separating the stamp with the above pattern transferred to the substrate to transfer the pattern formed with the nanowire material to the substrate including, Intaglio transfer method.

2. In paragraph 1, The above nanowire material is an anisotropic nanomaterial. Intaglio transfer method.

3. In paragraph 2, The above anisotropic nanomaterial is a silver (Ag) nanowire. Intaglio transfer method.

4. In paragraph 2, The above anisotropic nanomaterial is an inorganic material. Intaglio transfer method.

5. In paragraph 4, The above inorganic material is a metal chalcogenide, Intaglio transfer method.

6. In paragraph 5, The above metal chalcogenide is selected from the group consisting of CdS, CdSe, WS2, and MoS2. Intaglio transfer method.

7. In paragraph 1, The above engraved trench is made of a material having a greater surface energy than the stamp. Intaglio transfer method.

8. In paragraph 1, In the step (S200) of transferring a pattern formed with a nanowire material to the stamp by contacting and separating the stamp from the negative trench where the pattern is formed, the contacting of the stamp to the negative trench is 600 g / cm 2 It is a pattern formed by applying the above force, Intaglio transfer method.

9. In paragraph 1, In the step (S300) of contacting and separating the stamp to which the above pattern has been transferred to the substrate and transferring the pattern formed of the nanowire material to the substrate, the pattern transferred to the substrate has an aspect ratio (L / D) of up to 1000. Intaglio transfer method.

10. In paragraph 1, In the step (S300) of contacting and separating the stamp to which the above pattern has been transferred to the substrate and transferring a pattern formed of a nanowire material to the substrate, the pattern transferred to the substrate has a pattern resolution of up to 7 ㎛. Intaglio transfer method.

11. Manufactured by the method of paragraph 1, Flexible electrode.

12. In paragraph 11, The above nanowire material is a silver (Ag) nanowire. Flexible electrode.

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