Method for patterning large area and manufacturing replica of biological surface structure by using secondary electrohydrodynamic instability

Abstract

One embodiment of the present invention provides a method for manufacturing a replica of a biological surface structure by using secondary electrohydrodynamic instability, and a method for patterning a large area by using secondary electrohydrodynamic instability. In the method for manufacturing a replica of a biological surface structure, of the present invention, an electric field that is a remote force is used rather than a mechanical compressive force as driving force so that a biological surface exhibiting flexible and non-uniform surface roughness can be used as a master mold, and secondary electrohydrodynamic instability is effectively controlled such that an intaglio replica is easily formed through structure growth in a non-protruding region, and thus a large area can be patterned.

Description

A method for fabricating large-area patterning and biosurface structure replicas using secondary electrohydraulic instability

[0001] The present invention relates to a large-area patterning method using secondary electrohydraulic instability.

[0002] In addition, the present invention relates to a method for manufacturing a replica of a biological surface structure using secondary electrohydraulic instability.

[0003] Traditional molding techniques or capillary force lithography use relatively weak capillary forces, so the aspect ratio of the replicated micropattern is low and there are problems such as partial replication.

[0004] Accordingly, techniques have been developed to replicate biological surfaces using low surface tension and viscosity, but these methods limit the range of materials available. However, simple capillary forces alone are not sufficient to precisely replicate complex nanoscale microstructures, making conventional molding techniques ineffective.

[0005] For example, when replicating nano-scale patterns, it is difficult to form a perfect replica because polymer fluids that behave solely by capillary force have difficulty completely penetrating the concave surface due to the very high Laplace pressure generated on the surface.

[0006] In addition, for uniform, large-area patterning, uniform contact between the master mold and the polymer thin film must be guaranteed, but it is difficult to achieve this with simple capillary force alone.

[0007] In addition, conventional nanoimprinting techniques achieve uniform large-area patterning by utilizing high mechanical compression force, but similarly, uniform large-area patterning requires uniform contact between the master mold and the polymer thin film.

[0008] When the master mold and the polymer thin film are in uniform contact, a complex alignment system is generally required to precisely control the distance and contact between the two, which can increase the process cost of the technique.

[0009] In addition, although the above nanoimprinting technique currently has a status as a dominant patterning technique, it has a problem in that the high mechanical compression force severely limits the use of flexible material substrates and master molds.

[0010] Generally, biosurfaces are composed of flexible materials, and when replicating such biosurfaces using nanoimprinting techniques, the flexible biosurface structures can be easily deformed due to high mechanical compressive force.

[0011] At this time, there is a problem that it is difficult to use the biosurface as a master mold because the 'buckling effect' caused by high mechanical compression force deforms the flexible biosurface structure.

[0012] In addition, since surfaces composed of complex microstructures generally exhibit uneven surface roughness, there has been a problem that it is difficult to replicate large areas precisely using conventional methods.

[0013]

[0014] The electrohydraulic instability discussed herein is known to facilitate control of the structural properties of polymer thin film surfaces. Its unique characteristic of utilizing an electric field as the driving force, rather than mechanical compression or capillary force, allows it to overcome the problems of the prior art described above. In particular, secondary electrohydraulic instability, which enables the formation of additional structures, may offer a new perspective on surface energy control.

[0015] Additionally, a secondary replication method (secondary electrohydraulic instability-based patterning), which produces negative replicas identical to those produced by conventional molding or nanoimprinting, can replicate microstructures in a fast and inexpensive manner.

[0016] In particular, the fact that it can allow uniform contact without a separate array system despite the procedural similarity shows the technological prospect of being able to technically replace existing nanoimprinting.

[0017] However, there is currently no systematic research on secondary replication methods, and these secondary negative replicas have not received much attention due to their small size, which is on the order of several to tens of micrometers.

[0018] Therefore, many challenges remain, including the need to replicate biosurface structures and achieve uniform large-area patterning in secondary replication methods.

[0019] <Prior Art Literature>

[0020] (Patent Document 1) Republic of Korea Publication Patent No. 10-2011-0032381

[0021] (Patent Document 1) Republic of Korea Publication No. 10-2019-0132324

[0022] The technical problem to be achieved by the present invention is to provide a method for manufacturing a replica of a biological surface structure.

[0023] The technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0024] The technical problem to be achieved by the present invention is to provide a uniform large-area patterning method based on secondary electrohydraulic instability.

[0025] The technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0026] In order to achieve the above technical task, one embodiment of the present invention provides a method for manufacturing a replica of a biological surface structure.

[0027] The method for manufacturing the biosurface structure replica according to one embodiment of the present invention is as follows:

[0028] A step of preparing a capacitor including a substrate having a liquid polymer layer formed thereon as a lower electrode and a mask pattern positioned spaced apart from the upper portion of the substrate as an upper electrode;

[0029] A step of applying current to the electrodes of the capacitor to generate an electric field to cause secondary electrohydraulic instability to form a liquid polymer layer in an intaglio pattern to manufacture an intaglio replica;

[0030] A step of manufacturing an intaglio replica by applying a metal material to the surface of the intaglio replica to form a metal layer; and

[0031] The method may include preparing a capacitor including a mask mold comprising a substrate having a liquid polymer layer formed as a lower electrode and a negative replica having a metal layer formed spaced apart from the upper portion of the substrate as an upper electrode, and applying a current to an electrode of the capacitor to generate an electric field to generate secondary electrohydraulic instability to form the liquid polymer layer in a negative pattern, thereby manufacturing a positive-shaped three-dimensional bio-surface structure replica.

[0032] Additionally, according to one embodiment of the present invention, in the step of preparing the capacitor, the mask pattern may be a biosurface structure.

[0033] In addition, according to one embodiment of the present invention, in the step of preparing the capacitor, the mask pattern may be a concave-convex structure having alternating protrusions and non-protrusions.

[0034] Additionally, according to one embodiment of the present invention, in the step of preparing the capacitor, the gap between the substrate on which the polymer layer is formed and the mask pattern may be 0 μm to 4 μm.

[0035] Additionally, according to one embodiment of the present invention, in the step of preparing the capacitor, the thickness of the liquid polymer layer may be 150 nm to 2000 nm.

[0036] Additionally, according to one embodiment of the present invention, the method for manufacturing a biosurface structure replica can be performed at a temperature higher than the glass transition temperature of the liquid polymer material.

[0037] Additionally, according to one embodiment of the present invention, in the step of manufacturing the negative replica, the voltage applied to the electrode may be 0.5 kV to 1.8 kV.

[0038] In addition, according to one embodiment of the present invention, in the step of manufacturing the negative replica, the electric field strength applied to the capacitor is 10 8 It can be more than V / m.

[0039] In addition, according to one embodiment of the present invention, in the step of manufacturing the negative replica, the initial growth rate for forming the negative pattern is 10 2 s -1 10 inland 7 s -1 It could be.

[0040] In addition, according to one embodiment of the present invention, in the step of manufacturing the negative replica,

[0041] The initial growth rate is given by the following equation 1(τ m ) is characterized by following the reciprocal of:

[0042] <Formula 1>

[0043]

[0044] In the above equation 1, η is the viscosity of the fluid film, γ is the surface tension of the fluid film, and ε r is the permittivity of the fluid film, ε0 is the permittivity of vacuum, U is the strength of the applied voltage, h0 is the thickness of the dielectric (fluid film), and d is the distance between the two electrodes.

[0045] Additionally, according to one embodiment of the present invention, in the step of manufacturing the negative replica on which the metal layer is formed, the metal layer may be composed of an electrically conductive metal material.

[0046] Additionally, according to one embodiment of the present invention, in the step of manufacturing the negative replica on which the metal layer is formed, the thickness of the metal layer may be 10 nm to 20 nm.

[0047] In addition, according to one embodiment of the present invention, in the step of manufacturing the three-dimensional biosurface structure replica,

[0048] The growth rate of the above 3D biosurface structure replica is expressed by Equation 1 (τ m ) can follow the inverse.

[0049] To achieve the above technical task, one embodiment of the present invention provides a large-area patterning method.

[0050] The large-area patterning method according to one embodiment of the present invention may include the steps of preparing a capacitor including a substrate having a liquid polymer layer formed thereon and a mask pattern positioned spaced apart from each other on an upper portion of the substrate; and the step of applying a current to an electrode of the capacitor to generate an electric field to cause secondary electrohydraulic instability to form a liquid polymer layer as an intaglio pattern.

[0051] Additionally, according to one embodiment of the present invention, the lower electrode of the battery may be a substrate, and the upper electrode may be a mask pattern.

[0052] Additionally, according to one embodiment of the present invention, the mask pattern may be a concave-convex structure having alternating protrusions and non-protrusions.

[0053] Additionally, according to one embodiment of the present invention, the gap between the substrate on which the polymer layer is formed and the mask pattern may be 200 nm to 2 μm.

[0054] Additionally, according to one embodiment of the present invention, the thickness of the liquid polymer layer may be 150 nm to 2000 nm.

[0055] Additionally, according to one embodiment of the present invention, it can be performed at a temperature range of 100°C to 180°C.

[0056] Additionally, according to one embodiment of the present invention, the applied voltage may be 0.2 kV to 2.1 kV to generate a high voltage pulse.

[0057] Additionally, according to one embodiment of the present invention, the applied electric field strength is 10 8 It can be more than V / m.

[0058] In addition, according to one embodiment of the present invention, the initial growth rate for forming the negative pattern is 3.57 s -1 3.5×105 s -1 It could be.

[0059] In addition, according to one embodiment of the present invention, the initial growth rate is expressed by Equation 1 (τ m ) can be the reciprocal of.

[0060] Additionally, according to one embodiment of the present invention, in the step of forming the liquid polymer layer into an engraved pattern, the overall shape and size of the substrate on which the pattern is formed can be controlled through unique edge analysis.

[0061] In addition, according to one embodiment of the present invention, in the step of forming the liquid polymer layer into an engraved pattern, the edge of the substrate on which the pattern is formed can be adjusted to a straight or round shape by the unique edge analysis.

[0062] In addition, according to one embodiment of the present invention, in the step of forming the liquid polymer layer into an engraved pattern,

[0063] The above unique edge analysis shows that the electrostatic pressure that induces the growth of the structure ( ) and the Laplace pressure that interferes with it ( )at It means the value, and the above If the value is less than 1, it forms a sharp corner, If the value is greater than 1, rounded corners can be formed. is equation 2, is equation 3.

[0064] <Formula 2>

[0065] And,

[0066] <Formula 3>

[0067] and,

[0068] In the above, η is the viscosity of the fluid film, γ is the surface tension of the fluid film, and ε r is the permittivity of the fluid film, ε0 is the permittivity of vacuum, U is the strength of the applied voltage, h0 is the thickness of the dielectric (fluid film), and d is the distance between the two electrodes.

[0069]

[0070] To achieve the above technical task, another embodiment of the present invention provides a patterned polymer film.

[0071] The patterned polymer film according to one embodiment of the present invention can be manufactured using a large-area patterning method.

[0072] A method for manufacturing a replica of a biological surface structure according to one embodiment of the present invention has the effect of enabling the use of a biological surface exhibiting flexible and uneven surface roughness as a master mold because it uses an electric field, which is a remote force rather than a mechanical pressing force, as a driving force.

[0073] In addition, the present invention has the effect of producing a precise negative replica by controlling the three-dimensional behavior of a polymer fluid in a secondary replication method after attaching a biological surface as a master pattern.

[0074] Additionally, the above engraved replicas can be reused as master molds through thin metal deposition.

[0075] Additionally, it is possible to replicate sophisticated biosurface structures through electrohydraulic secondary replication by reusing the biosurface master mold.

[0076] At this time, the resulting precisely replicated bio-surface structure can implement various original surface properties (e.g., superhydrophobicity, antibacterial effect, etc.), making it possible to apply it in various industrial fields.

[0077] According to another embodiment of the present invention, a uniform large-area patterning method based on secondary electrohydraulic instability effectively controls secondary electrohydraulic instability, thereby enabling the easy formation of negative replicas through structure growth in non-protruding areas. In addition, since the applied electric field electrostatically attracts the two electrodes (master mold and substrate), uniform contact is possible without the need for separate equipment or systems. Therefore, according to the present invention, large-area patterning is possible even with non-uniform contact.

[0078] In addition, the uniform large-area patterning method based on secondary electrohydraulic instability according to one embodiment of the present invention is such that the planar growth of the secondary structure exhibits unique edges according to the master pattern, and active control of specific unique edges can improve the uniformity of the replicated structure.

[0079] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the composition of the invention described in the claims.

[0080] Figure 1 is a schematic diagram illustrating a method for precisely replicating a given biosurface structure through secondary electrohydraulic instability.

[0081] Figure 2 is a schematic diagram illustrating a method for replicating a biosurface structure through a negative replication process of an electrohydraulic control technique.

[0082] Figure 3 is a schematic diagram and graph illustrating the electrohydraulic instability induced at the polymer-polymer interface in the electrohydraulic secondary replication method and a method for controlling it through numerical analysis.

[0083] Figure 4 is a schematic diagram and scanning electron microscope image illustrating a method of replicating a biosurface structure by secondary instability.

[0084] Figure 5 is a scanning electron microscope image showing the results of controlling electrohydraulic instability at a polymer-polymer interface.

[0085] Figure 6 shows the result of producing the original biosurface structure using a negative replica coated with a metal thin film as a master mold.

[0086] Figure 7 shows the results of controlling the vertical growth of the cicada wing structure as the electric field strength increases.

[0087] Figure 8 shows the results of implementing an antibacterial effect on a surface replicating a cicada wing nanostructure.

[0088] Figure 9 shows the results of replicating the micro-nano hybrid structure on the surface of a rose petal using an electrohydraulic secondary replication method.

[0089] Figure 10 is an image showing a comparison of vertical replication fidelity according to an increase in applied voltage (electric field) intensity.

[0090] Figure 11 shows the results of observing the trend in the replication area of ​​a rose petal hybrid structure according to plane growth.

[0091] Figure 12 is a schematic diagram showing the results of uniform large-area patterning through selective control of the edges and increase in the growth rate and the planar growth of the replicated micropattern through secondary electrohydraulic instability.

[0092] Figure 13 is a schematic diagram and scanning electron microscope image showing the growth of positive replicas due to primary instability and the growth of negative replicas due to secondary instability.

[0093] Figure 14 is a scanning electron microscope image showing the experimental results according to the secondary replication method induced after the formation of the primary structure (relief pattern).

[0094] Figure 15 is a schematic diagram showing the planar growth in the structure replication method by secondary instability.

[0095] Figure 16 is a schematic diagram showing a comparison of the behavior of polymer fluids forming negative patterns in a secondary replication method.

[0096] Figure 17 shows the results of a computer simulation of the planar aspect of polymer fluid flow in a secondary replication method.

[0097] Figure 18 is a scanning electron microscope image comparing different unique edge shapes.

[0098] Figure 19 shows the results of analysis of different unique edge formations.

[0099] Figure 20 shows the growth rate of the electrohydraulic structure (τ0 / τ m ) is the result of a computer simulation showing the comparison of the area / size of the secondary structure that is ultimately determined.

[0100] Figure 21 shows experimental results showing that the planar structure growth forms rounded corners (AC) despite the high growth rate.

[0101] Figure 22 shows experimental results showing that, despite the high growth rate, the planar structure growth forms angular and straight edges (ZZ).

[0102] Figure 23 is a result of the present invention that achieves uniform large-area patterning even with uneven contact.

[0103] Hereinafter, the present invention will be described with reference to the attached drawings. However, the present invention can be implemented in various different forms and is therefore not limited to the embodiments described herein. In the drawings, irrelevant parts have been omitted for clarity of description, and similar parts have been designated with similar reference numerals throughout the specification.

[0104] Throughout the specification, when a part is said to be "connected (connected, contacted, joined)" to another part, this includes not only cases where it is "directly connected," but also cases where it is "indirectly connected" with another part in between. Furthermore, when a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0105] The terminology used herein is merely used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0106]

[0107] Below, the present invention will be described with reference to the drawings presented in this specification. Note that the drawings may be exaggerated to illustrate the features of the present invention. In such cases, it is preferable to interpret them in light of the overall intent of this specification.

[0108]

[0109] Referring to FIGS. 1 to 11, a method for manufacturing a biosurface structure replica according to one embodiment of the present invention is described.

[0110] A method for manufacturing a biosurface structure replica according to one embodiment of the present invention,

[0111] The method may include the steps of: preparing a capacitor including a substrate having a liquid polymer layer formed as a lower electrode and a mask pattern positioned spaced apart from the upper portion of the substrate; applying a current to the electrode of the capacitor to generate an electric field to cause secondary electrohydraulic instability to form the liquid polymer layer in a negative pattern to manufacture a negative replica; applying a metal material to a surface of the negative replica to manufacture a negative replica having a metal layer formed thereon; and preparing a capacitor including a mask mold comprising a substrate having a liquid polymer layer formed as a lower electrode and a negative replica having a metal layer formed spaced apart from the upper portion of the substrate as an upper electrode; applying a current to the electrode of the capacitor to generate an electric field to cause secondary electrohydraulic instability to form the liquid polymer layer in a negative pattern to manufacture a positive-shaped three-dimensional biosurface structure replica.

[0112] In the first step, a step of preparing a capacitor including a substrate having a liquid polymer layer formed thereon as a lower electrode and a mask pattern positioned spaced apart from the upper portion of the substrate as an upper electrode may be included. (S100)

[0113] At this time, the mask pattern is characterized by being a bio-surface structure.

[0114] At this time, the biosurface structure uses a cicada wing nanostructure and a rose leaf micro-nano hybrid structure as representative biosurface structures, but does not limit the scope of the present invention, and various biosurface structures such as an anisotropic hybrid structure of a rice leaf surface, a porous structure of a black butterfly wing, and a lotus leaf micro-nano hybrid structure are allowed.

[0115] In addition, the present invention preferably has a capacitor form composed of upper and lower electrodes for uniform electric field application across the entire thin film surface.

[0116] The lower electrode of the battery used in the present invention is characterized in that it is a substrate, and the upper electrode is a mask pattern.

[0117] At this time, the mask pattern is characterized by having a rough structure with alternating protrusions and non-protrusions.

[0118] The object of the present invention, in which the electrohydraulic instability is induced, is a fluid thin film surface, which is generally characterized by a thickness of several micrometers or less and a liquid phase material exhibiting the properties of an incompressible Newtonian fluid within an acceptable range.

[0119] At this time, in the present invention, 'polymer fluid' means a polymer thin film that has secured fluidity in a heat treatment situation above the glass transition temperature. The polymer material is not particularly limited in type, but polystyrene, poly(methyl methacrylate), polyvinylidene fluoride, poly(vinylidene fluoride-trifluoroethylene), polyvinyl alcohol, polyvinyl acetate, polydimethylsioxane, polyvinylpyrrolidone, ethyl cellulose or polycaprolactone, poly(chlorotrifluoroethylene), etc. can be used.

[0120] At this time, the present invention includes a step of using the once-replicated negative replica as a master mold again, and it is appropriate to use a water-soluble polymer to preserve the structure of the final replica when making the master mold.

[0121] As water-soluble polymers, polyvinyl alcohol, polyethylene glycol, polyvinylpyrrolidone, dextran, carboxymethyl cellulose, and salmon deoxyribo nucleic acid are preferable.

[0122] At this time, the thickness of the liquid polymer layer of the present invention is characterized by being 150 nm to 2000 nm.

[0123] At this time, when the thickness of the liquid polymer layer is 150 nm to 2000 nm, it is suitable for inducing secondary instability and implementing the secondary replication method accordingly.

[0124] In addition, in the present invention, since thin film fluidity must be secured for structural deformation according to application of electrostatic pressure, a process temperature higher than the glass transition temperature is required.

[0125] Accordingly, the present invention is characterized in that it is performed in a temperature range of 100°C to 200°C.

[0126] For example, one embodiment of the present invention uses a polystyrene thin film, and the process can be performed above the glass transition temperature (about 100 °C).

[0127] In addition, the present invention preferably has a uniform thin film surface for uniform electric field application. At this time, processes such as spin coating, spray coating, and dip coating can be performed to apply a polymer thin film on the substrate.

[0128] At this time, the gap between the substrate on which the polymer layer of the present invention is formed and the mask pattern is characterized by being 0 to 4 μm.

[0129] If the gap between the substrate on which the polymer layer is formed and the mask pattern exceeds 4 μm, there may be a problem in that it is difficult to form an effective structure due to insufficient electric field strength.

[0130] In the second step, a step of applying current to the electrodes of the capacitor to generate an electric field to cause secondary electrohydraulic instability to form a liquid polymer layer in an intaglio pattern to manufacture an intaglio replica may be included. (S200)

[0131] For an effective secondary replication method, an air layer less than 2 micrometers thick is preferred.

[0132] In the present invention, the gap between the substrate on which the polymer layer is formed and the mask pattern is characterized by being 0 to 4 μm.

[0133] In addition, the power supply connected to the upper / lower electrodes generates a high voltage pulse to generate an electric field. At this time, 0.5 kV or more is appropriate, and the maximum applied voltage can be adjusted through the thickness of the air layer, the insulating properties of the substrate and the thin film, and the circuit design of the power supply.

[0134] Additionally, preferably, the voltage applied to the electrode may be 0.5 kV to 1.8 kV.

[0135] In addition, for effective induction of secondary instability, the electric field strength on the surface of the fluid film should be 10 8 It is desirable that it be V / m or more.

[0136] At this time, in order to apply a uniform electric field in the capacitor structure and to have a uniform surface of the polymer thin film to be applied, it is preferred to use a flat rigid substrate (e.g., silicon, silicon oxide, ITO glass, general glass, etc.), but this does not limit the content of the invention, and due to the nature of the present invention, a flexible substrate (e.g., PET substrate, general polymer sheet, etc.) can also be used.

[0137] Additionally, the substrate coated with the polymer thin film is suitable for use as a lower electrode in a capacitor structure.

[0138] At this time, in the case of an insulating substrate, deposition of a conductive material is required or a high applied voltage that exceeds the insulating properties is required.

[0139] In addition, in order to effectively induce secondary instability, a 'high-speed control' method that rapidly increases the growth speed of the electrohydraulic structure is effective. In the present invention, the reciprocal of the characteristic time, which refers to the initial growth speed of the structure over the entire thin film surface, 1 / We use a method to increase the relatively slow rate of secondary instability development by increasing the .

[0140] Specifically mentioned above is as shown in Equation 1 below.

[0141] <Formula 1>

[0142]

[0143] In the above equation 1 is the viscosity of the fluid film, is the surface tension of the fluid film, is the permittivity of the fluid thin film, is the vacuum permittivity, U is the applied voltage, h0 is the dielectric (fluid thin film) thickness, and d is the distance between the two electrodes.

[0144] In the above formula, 1 / The increase can accelerate the growth of secondary structures, which were relatively slow, and help to form structures reproducibly in a short period of time.

[0145] Through this, high 1 / The secondary instability-based structures formed at small inter-electrode distances are negative replicas of the master pattern in the opposite shape, yielding results similar to conventional nanoimprinting or molding techniques.

[0146] At this time, in the present invention, the 'secondary replication method' means a process in which the upper electrode structure is negatively replicated by 'secondary electrohydraulic instability'.

[0147] The above 'secondary electrohydraulic instability' refers to a phenomenon in which a polymer fluid that has been first unstable forms a structure having the same shape as the protrusion of the upper electrode, and then the polymer fluid forms a structure due to an applied electric field in the area below the non-protrusion.

[0148] The above 'electrohydraulic instability' refers to a phenomenon in which microscopic structures are formed on the surface of a polymer thin film to lower the free energy (electrostatic energy) stored inside the capacitor.

[0149] 'Electrohydraulic control technique' refers to a technique for producing artificial surface structures based on the above electrohydraulic instability.

[0150] In order to effectively induce the above-mentioned secondary replication method, the distance between the electrodes needs to be sufficiently small while implementing the electrohydraulic control technique.

[0151] ‘Inter-electrode distance’ refers to the distance between the upper and lower electrodes.

[0152] A 'sufficiently small distance between electrodes' is generally appropriate when the filling ratio (= thickness of the applied polymer film / distance between electrodes, filling ratio) is 0.5 or more.

[0153] Additionally, 'negative replication' means that a structure of the opposite shape to that given to the upper electrode is formed on the surface of a polymer thin film on the lower electrode.

[0154] Therefore, the biosurface structure can be formed as a negative replica on the surface of a polymer thin film located on the lower electrode through a secondary replication method of an electrohydraulic control technique.

[0155] Referring to (a) of Fig. 2, negative replication of a biosurface structure through an electrohydraulic secondary replication method is illustrated.

[0156]

[0157] In the third step, a step of manufacturing an intaglio replica by applying a metal material to the surface of the intaglio replica to form a metal layer may be included. (S300)

[0158] The resulting negative replica of the bio-surface structure, which will be described later, can then be used as a master pattern for electrohydraulic control techniques.

[0159] Figure 2(b) illustrates the process of forming a replica of a biological surface structure in an electrohydraulic secondary replication method through reuse of an engraved replica.

[0160] At this time, the negative replica is formed of a polymer, in which case a polymer-polymer interface can be formed due to contact with another polymer thin film located on the lower electrode.

[0161] In this case, if an electrohydraulic control technique is implemented, instability can be induced at the polymer-polymer interface, which can lead to the formation of additional structures.

[0162] Since the above additional structures are an undesirable consequence of replicating the original biosurface structures, the electro-hydrodynamic instability of the polymer-polymer interface needs to be suppressed.

[0163] At this time, the present invention can disclose a method for selectively controlling electrohydraulic instability.

[0164] Figure 3 is a schematic diagram illustrating electrohydraulic instability induced at a polymer-polymer interface.

[0165] Time constant of electrohydrostatic instability induced at polymer-polymer interface ( ) is as shown in Equation 4 below.

[0166] <Formula 4>

[0167]

[0168] In the above formula is the dielectric constant of the polymer thin film (thin film 1) on the lower electrode, is the permittivity of the polymer thin film under the upper electrode, E1 is the electric field strength applied to thin film 1, E2 is the electric field strength applied to thin film 2, is the interfacial tension between thin films 1 and 2, and C(h1,h2, , ) is a function of the height and viscosity of the two polymer films.

[0169] At this time, considering that the dielectric constant, interfacial tension, and electric field strength are maintained constant in the electrohydraulic control method, the instability control at the polymer-polymer interface in the above equation is C(h1,h2, , ) is lowered, and the above C(h1,h2, , ) is as shown in Equation 5 below.

[0170] <Formula 5>

[0171]

[0172] In the above formula, h1 is the thickness of thin film 1, where is the viscosity of thin film 1, h2 is the thickness of thin film 2, is the viscosity of thin film 2.

[0173] Viscosity ratio (R= ) and the thickness ratio (S=-h2 / h1), the above equation can be simplified.

[0174] Considering the experimental conditions used in the embodiment of the present invention, assuming h1=-h2, C is as shown in Equation 6 below.

[0175] <Formula 6>

[0176]

[0177] Additionally, using the thickness ratio S, C can be expressed as in Equation 7 below.

[0178] <Formula 7>

[0179]

[0180] In order to lower C above, R or S must be increased. In this case, the present invention can use a method of lowering R and S by increasing the viscosity and reducing the thickness of thin film 2.

[0181] Therefore, the rate of instability development induced at the polymer-polymer interface can be suppressed by applying a thin layer of metal material with a viscosity generally very thick, i.e., close to infinity, on the negative replica.

[0182] Therefore, the negative replica produced by applying a conductive metal material at the same time can be used as the upper electrode.

[0183] At this time, the metal layer may be composed of an electrically conductive metal material.

[0184]

[0185] In the fourth step, a capacitor including a mask mold comprising a substrate having a liquid polymer layer formed as a lower electrode and a negative replica having a metal layer formed spaced apart from the upper portion of the substrate as an upper electrode is prepared, and a step of applying a current to an electrode of the capacitor to generate an electric field to cause secondary electrohydraulic instability to form the liquid polymer layer in a negative pattern to manufacture a positive-shaped three-dimensional biosurface structure replica may be included. (S300)

[0186] The method for manufacturing a three-dimensional biosurface structure replica in the shape of a positive image of the present invention uses the same replication method as the step of manufacturing a negative replica in the second step described above, so that a structure identical to the original biosurface structure can be ultimately formed.

[0187] Specifically, the present invention allows a polymer fluid that behaves by secondary instability to flow three-dimensionally, which can be divided into planar flow and vertical flow.

[0188] At this time, the area and uniformity of the replica structure can be determined in the 'planar flow', i.e., 'planar growth', and the height / aspect ratio of the replica structure and the tip portion in the vertical direction can be determined in the 'vertical flow', i.e., 'vertical growth'.

[0189] Additionally, the three-dimensional flow of polymer fluids exhibits high magnitudes of 1 / , indicating rapid growth of electrohydraulic structures. can be controlled in the way it is maintained.

[0190] At this time, the plane growth of the structure is 1 / The viscosity of the fluid film contributing to ) has a great influence, and the lower the viscosity, the better the area and uniformity of the structure formed by the secondary replication method.

[0191] This is because the fluctuating polymer film in the electrohydraulic phenomenon behaves as a Poiseuille flow, and the speed of this flow is inversely proportional to the viscosity.

[0192] Also, the vertical growth of the structure is 1 / The applied electric field strength (applied voltage) has a significant influence, and the higher the electric field, the greater the aspect ratio / height of the structure formed by the secondary replication method.

[0193] The present invention can utilize a method of controlling an electric field to enhance vertical growth of a structure.

[0194] Additionally, in the secondary replication method, the polymer thin film located under the mold structure can grow upward by the applied electric field.

[0195] At this time, the main driving force is the electrostatic pressure, and the force that opposes vertical growth is the Laplace pressure, and the final height and end shape of the structure can be determined through the competitive relationship between the two.

[0196] Additionally, a higher electric field (applied voltage) ensures effective vertical growth, enabling a high aspect ratio to be achieved, and allows for complete penetration into the mold structure, enabling the end shape to be precisely replicated.

[0197] In addition, the present invention can appropriately control the three-dimensional flow of polymer fluid in an electrohydraulic secondary replication method by controlling viscosity and electric field intensity.

[0198] Therefore, in parameter control, the present invention is 1 / in a way that lowers the viscosity and increases the electric field (applied voltage). By increasing the , not only can the process time be drastically shortened, but also the area, uniformity, and aspect ratio of the replicated bio-surface structure can be appropriately controlled.

[0199] As a result, it is possible to precisely replicate the original three-dimensional biosurface structure while achieving uniform large-area replication.

[0200] After the above electrohydraulic control technique is completed, the replicated biosurface structure can be obtained by separating the master mold or, in the case of a water-soluble master mold, immersing it in water.

[0201] The above-described precisely replicated structure can replicate even the unique characteristics of the original biological surface, and in an embodiment of the present invention, the antibacterial effect on the surface of the replicated structure can be verified through replication of cicada wings.

[0202] Therefore, the method for manufacturing a replica of a biological surface structure according to one embodiment of the present invention has the effect of enabling the use of a biological surface exhibiting flexible and uneven surface roughness as a master mold because it uses an electric field, which is a remote force rather than a mechanical pressing force, as a driving force.

[0203] In addition, the present invention has the effect of producing a precise negative replica by controlling the three-dimensional behavior of a polymer fluid in a secondary replication method after attaching a biological surface as a master pattern.

[0204] Additionally, the above engraved replicas can be reused as master molds through thin metal deposition.

[0205] Additionally, it is possible to replicate sophisticated biosurface structures through electrohydraulic secondary replication by reusing the biosurface master mold.

[0206] At this time, the resulting precisely replicated bio-surface structure can implement various original surface properties (e.g., superhydrophobicity, antibacterial effect, etc.), making it possible to apply it in various industrial fields.

[0207]

[0208] Below, Figures 1 to 11 are described.

[0209] Figure 2 shows a method for replicating a bio-surface structure by electrohydraulic instability, and more specifically, a series of processes for obtaining a desired replica after manufacturing a master mold.

[0210] Typically, the primary instability induced under the protrusions of the master pattern grows structures of the same shape as the master pattern, whereas the secondary electrohydraulic instability additionally occurring under the non-protrusions pulls the polymer fluid upward to fill the non-protrusion areas, which can result in the formation of secondary replica structures different from the primary structures.

[0211] In the present invention, the 'secondary replication method' or 'electrohydraulic secondary replication method' refers to a negative replication production process formed through the secondary electrohydraulic instability described above.

[0212] Unlike existing patterning methods that utilize capillary force or mechanical compression force, the above secondary replication method utilizes an electric field, or more precisely, electrostatic pressure, to enable polymer fluid behavior even at a certain distance.

[0213] At this time, these process characteristics can allow patterning even with uneven contact.

[0214] Additionally, in the present invention, 'uneven contact' means that in the electrohydraulic control technique, the distance between electrodes (i.e., the thickness of the air layer between the upper and lower electrodes) is not distributed equally across the entire surface of the thin film on the lower electrode.

[0215] In detail, (1) the polymer fluid is pulled up to a predetermined distance according to the rapid growth rate to form a structure, and (2) at the same time, since the voltage applied between the two electrodes pulls the upper and lower electrodes due to the Coulomb force (electrostatic force), uniform contact can be achieved without a separate device.

[0216] In the above secondary replication method, the polymer fluid behavior occurs in three dimensions, and can be divided into (1) planar growth and (2) vertical growth.

[0217] (1) As for the initially formed secondary replica, it grows as if it were spreading out laterally, and the final replica size (area) can be determined in this process.

[0218] In addition, with respect to (2), the vertical growth of the secondary structure toward the non-protruding portion can determine the aspect ratio of the structure according to the Laplace pressure that attempts to stabilize the surface.

[0219] Through the above Fig. 2a, it is possible to illustrate the formation of a negative-shaped structure through a secondary replication method after positioning the bio-surface on the upper electrode.

[0220] In addition, the process of forming the original bio-surface structure through a secondary replication method using the negative replica produced at this time as a master mold can be illustrated through Fig. 2b.

[0221] In addition, it can be illustrated that the original bio-surface structure is obtained from the above through Fig. 2c.

[0222] Figure 3 illustrates the electrohydraulic instability induced at the polymer-polymer interface in the electrohydraulic secondary replication method [Figure 3a] and a method for controlling it through numerical analysis [Figure 3b].

[0223]

[0224] Figure 4 can illustrate a biosurface structure replicated by secondary instability.

[0225] At this time, Fig. 4a illustrates the process of replicating a given biosurface structure (cicada wing nanostructure) through an electrohydraulic secondary replication method, and it can be confirmed that three-dimensional flow control of the polymer fluid is required.

[0226] Additionally, Fig. 4b is a scanning electron microscope image showing a tendency for the area and uniformity of the planar negative structure to improve with increasing growth rate (decreased viscosity).

[0227] Figure 4c is a scanning electron microscope image showing that the replicated object (cicada wing nanostructure) was precisely replicated in three dimensions as a result of the experiment.

[0228] The above figure 4d can illustrate that when the negative replica is made with a water-soluble polymer, it can be easily dissolved in water.

[0229]

[0230] Figure 5 illustrates that polymer-polymer interface instability is effectively controlled through thin metal material deposition (see Example 1).

[0231] Referring to Fig. 5a, it can be confirmed that when a metal film is not deposited, replication fidelity is reduced due to instability at the polymer-polymer interface, but when a metal film is deposited, the development of the instability is suppressed, and replication fidelity is improved.

[0232]

[0233] Figure 6 shows the result of producing the original biosurface structure using a negative replica coated with a metal thin film as a master mold.

[0234] In particular, Fig. 6 illustrates the improvement in area and uniformity according to planar growth control in the electrohydraulic secondary replication method.

[0235] Figure 6a illustrates that uniform large-area replication of biosurface structures can be achieved through planar growth control.

[0236] In addition, Fig. 6b shows the results of scanning electron microscopy observations showing that the area and uniformity of the planar negative structure improve with increasing growth rate (decreased viscosity).

[0237] Figure 6c shows the result that the replicated object (cicada wing nanostructure) and the replicated structure have the same shape.

[0238] Figure 6d shows the area (approximately 1㎠) and uniformity of the replicated cicada wing nanostructure. To effectively visualize the area of ​​the replicated structure, a platinum thin film (thickness: 10 nm) was applied. At this time, it can be confirmed that light is absorbed on the surface, making the replicated area appear visibly black.

[0239]

[0240] Figure 7 shows the results of increasing the aspect ratio / height of the replication structure according to vertical growth control in the electrohydraulic secondary replication method.

[0241] Figure 7a is a scanning electron microscope image showing the tendency of the aspect ratio / height of the structure to increase with increasing electric field strength.

[0242] Figure 7b shows the degree of replication fidelity of a replicated structure as the electric field strength increases by synthesizing experimental and simulation results.

[0243] Additionally, Fig. 7c shows the simulation results showing that the aspect ratio / height of the biosurface structure (cicada wing structure) improves as the electric field strength increases.

[0244]

[0245] Figure 8 shows the results of implementing an antibacterial effect on the cicada wing nanostructure replica surface.

[0246] Referring to Figure 8, the surface of the biological cicada wing exhibits an antibacterial effect that prevents bacteria from multiplying. As a result of precisely replicating the surface through the present invention, it can be confirmed that the antibacterial effect, which is an important feature of the surface, is also replicated.

[0247] Figure 8a shows the results of confocal fluorescence microscopy observations of the tendency of bacteria (E. coli, Escherichia coli) on the replica surface to die over time (green: live E. coli, red: dead E. coli).

[0248] Figure 8b illustrates the implementation of the antibacterial effect through a comparison between the replica surface and the control subject (PS thin film), and after 90 minutes, less than 20% of the bacteria were alive on the replica surface.

[0249] Figure 8c shows the results in the comparison group (PS thin film), where it can be confirmed that most bacteria are alive even after 90 minutes.

[0250] Figure 8d illustrates the bactericidal effect implemented on the replica surface, and it can be confirmed that bacteria are penetrated and killed on the precisely replicated cicada wing nanostructure surface.

[0251]

[0252] Figure 9 shows the result of negative replication of a micro-nano hybrid structure of a rose petal (Rosa hybrid tea petal) as a biosurface to be replicated.

[0253] The above figure 9a is an optical microscope image and a scanning electron microscope image of the surface structure of a rose petal.

[0254] The above rose petals have a three-dimensional micro-nano hybrid structure with wrinkles of hundreds of nanometers mixed with cone-shaped structures with rounded ends of tens of micrometers.

[0255] The above figure 9b shows the result of producing a negative-shaped structure through a secondary replication method using rose petals as the upper electrode. At this time, it can be confirmed that uniform negative replication can be achieved over a large area (approximately 5㎠).

[0256]

[0257] Figure 10 shows the result of producing the original rose petal surface structure using a negative replica of the rose petal surface coated with a metal film as a master mold.

[0258] Figure 10a shows the results showing that the replication fidelity of the structure is improved by increasing the electric field strength as the voltage increases.

[0259] Figure 10b shows that rose petals with wrinkles of hundreds of nanometers mixed with cone-shaped structures with rounded ends of tens of micrometers were successfully replicated at 1.3 kV.

[0260]

[0261] Figure 11 shows the area and uniformity of the micro-nano hybrid structure on the surface of the replicated rose petal.

[0262] Figure 11a shows the results showing that the vertical fidelity of the structure is improved by increasing the electric field strength as the voltage increases.

[0263] Figure 11b shows the result of a full-scale replication of the rose petal surface micro-nano hybrid structure (4 cm2).

[0264] Below, the proof for the detailed experiment will be explained in detail in the experimental example below.

[0265]

[0266] Referring to FIGS. 12 to 23, a large-area patterning method using secondary electrohydraulic instability according to an embodiment of the present invention is described.

[0267] Referring to Figure 12, a large-area patterning method according to one embodiment of the present invention is

[0268] The method may include a step of preparing a capacitor including a substrate having a liquid polymer layer formed thereon and a mask pattern positioned spaced apart from the substrate; and a step of applying a current to an electrode of the capacitor to generate an electric field to cause secondary electrohydraulic instability, thereby forming the liquid polymer layer as an engraved pattern.

[0269]

[0270] Hereinafter, a large-area patterning method according to another embodiment of the present invention will be described.

[0271] A large-area patterning method according to one embodiment of the present invention is:

[0272] The method may include a step of preparing a capacitor including a substrate having a liquid polymer layer formed thereon and a mask pattern positioned spaced apart from the substrate; and a step of applying a current to an electrode of the capacitor to generate an electric field to cause secondary electrohydraulic instability, thereby forming the liquid polymer layer as an engraved pattern.

[0273] In the first step, a step may be included of preparing a capacitor including a substrate having a liquid polymer layer formed thereon and a mask pattern positioned spaced apart from each other on an upper portion of the substrate.

[0274] First, the present invention is preferably in the form of a capacitor composed of upper and lower electrodes for uniform electric field application across the entire thin film surface.

[0275] The lower electrode of the battery used in the present invention is characterized in that it is a substrate, and the upper electrode is a mask pattern.

[0276] At this time, the mask pattern is characterized by having a rough structure with alternating protrusions and non-protrusions.

[0277] The object of the present invention, in which the electrohydraulic instability is induced, is a fluid thin film surface, which is generally characterized by a thickness of several micrometers or less and a liquid phase material exhibiting the properties of an incompressible Newtonian fluid within an acceptable range.

[0278]

[0279] At this time, the thickness of the liquid polymer layer of the present invention is characterized by being 150 nm to 2000 nm.

[0280] At this time, when the thickness of the liquid polymer layer is 150 nm to 2000 nm, it is suitable for inducing secondary instability and implementing the secondary replication method accordingly.

[0281] In addition, in the present invention, since thin film fluidity must be secured for structural deformation according to application of electrostatic pressure, a process temperature higher than the glass transition temperature is required.

[0282] Accordingly, the present invention is characterized in that it is performed in a temperature range of 100°C to 180°C.

[0283] For example, one embodiment of the present invention uses a polystyrene thin film, and the process can be performed above the glass transition temperature (about 100 °C).

[0284] In addition, the present invention preferably has a uniform thin film surface for uniform electric field application. At this time, processes such as spin coating, spray coating, and dip coating can be performed to apply a polymer thin film on the substrate.

[0285] At this time, the gap between the substrate on which the polymer layer of the present invention is formed and the mask pattern is characterized by being 200 nm to 2 μm.

[0286] If the distance between the substrate on which the polymer layer is formed and the mask pattern is less than 200 nm, problems such as insulation breakdown may occur, and if it exceeds 2 μm, the distance may be too far, resulting in a problem in which patterning is not performed due to insufficient electric field strength.

[0287]

[0288] In the second step, a step of applying current to the electrodes of the capacitor to generate an electric field to cause secondary electrohydraulic instability and form a liquid polymer layer in a negative pattern may be included.

[0289] The present invention utilizes the property that when a high electric field is applied to a fluid thin film, the thin film surface becomes unstable and structural deformation occurs at this time.

[0290] Referring to Fig. 13(a), when a standardized micropattern is used as a top electrode, the spatial distribution of the electric field directly reflects the structural characteristics of the top electrode. However, structural deformation is controlled according to the spatial arrangement of instability, and a micropattern with the same shape as the top electrode is replicated. This property is a primary electrohydraulic instability, and since it is aligned to a place where the electric field strength is high, structural deformation actively occurs under the protrusion of the top electrode.

[0291] However, structural deformations are also observed or predicted beneath the non-protrusions where the electric field strength is relatively weak, and are called 'secondary electrohydraulic instabilities (secondary instabilities)' because they are induced after the instability beneath the protrusions in time.

[0292] At this time, if the distance between the electrodes is sufficiently small, the primary structure comes into contact with the master pattern protrusion, and the energy stored in the capacitor is used to form additional structures.

[0293] At this time, the structure (secondary structure) due to secondary instability growing toward the non-protruding portion can completely fill the non-protruding portion area and ultimately produce a structure (negative replica) of the opposite shape to the master pattern.

[0294] At this time, the behavior of the polymer fluid in the secondary structure growth of the present invention is three-dimensionally performed as (1) planar growth and (2) vertical growth.

[0295] According to research conducted to date, the planar growth of these secondary structures is on the order of several to tens of micrometers, making uniform large-area replication difficult.

[0296] Accordingly, the present invention, taking into account the fact that the difficulty in inducing secondary electrohydraulic instability lies in the relatively slow growth rate, introduces a 'high-speed control method' that increases the inverse of the characteristic time indicating the structure growth rate.

[0297] The above high-speed control method can significantly increase the area of ​​the pattern structure in secondary replication.

[0298] At this time, when the standard pattern is used as the upper electrode, the secondary replication structure exhibits a polygonal shape, which is a unique phenomenon not observed in general electrohydraulic patterning.

[0299] Based on the electrohydraulic fluid behavior simulation and experimental results (Figs. 5 and 6), the present invention proposes a method for controlling the unique edge of a structure.

[0300] Additionally, by selectively controlling specific edge growth involved in increasing the structure area, not only the replica size (area) but also the structure uniformity can be improved.

[0301] In summary, uniform large-area patterning can be achieved even in secondary instability patterning through (1) rapid growth of electrohydraulic secondary structures and (2) selective control of intrinsic edges.

[0302] At this time, the present invention is characterized in that the power supply connected to the upper electrode (substrate) / lower electrode (mask pattern) generates a high voltage pulse to generate an electric field, which is 0.2 kV to 2.1 kV.

[0303] If the above high voltage pulse is less than 0.2 kV, there may be a problem of insufficient electric field strength, and if it exceeds 2.1 kV, there may be a problem of damage to the pattern structure due to insulation breakdown during the patterning replication process. The maximum applied voltage can be controlled through the thickness of the air layer, the insulation characteristics of the substrate and the thin film, and the circuit design of the power supply.

[0304] In addition, to induce effective secondary instability, the electric field strength on the surface of the fluid film is 10 8 It is characterized by a value of V / m or more.

[0305] At this time, in order to apply a uniform electric field in the capacitor structure and to have a uniform surface of the polymer thin film to be applied, it is preferred to use a flat rigid substrate (e.g., silicon, silicon oxide, ITO glass, general glass, etc.), but this does not limit the content of the invention, and due to the nature of the present invention, a flexible substrate (e.g., PET substrate, general polymer sheet, etc.) can also be used.

[0306] Additionally, substrates coated with polymer thin films are suitable for use as lower electrodes in capacitor structures. In this case, insulating substrates require deposition of conductive materials or require high applied voltages that exceed their insulating properties.

[0307] At this time, the spatial distribution of the electric field intensity is determined by the structure of the upper electrode, and the uneven structure of the master pattern generates an electric field intensity difference due to a minute distance difference, and the master pattern to be replicated is suitably an uneven structure composed of alternating protrusions and non-protrusions, and the size-to-distance ratio between the two is suitably 1:2 or less, but varies depending on the material, applied voltage, and reaction speed and is not limited to the above-described ratio.

[0308] At this time, the present invention requires a step in which the first formed primary structure comes into contact with the protrusion and induces secondary structure growth by having a small distance between electrodes. In one embodiment of the present invention, the structured top electrode (mask pattern mold) used allows for various sizes / periods / heights, etc., and can also be used on a biological surface with a complex structure.

[0309]

[0310] The present invention essentially requires the following process.

[0311] (1) The step in which the distance between the electrodes in the electrohydraulic patterning is sufficiently small so that the primary structure comes into contact with the protrusion, (2) the step in which an additional surface structure is formed to reduce the electrostatic energy stored inside the capacitor, and (3) the step in which the formed secondary replica structure forms a unique edge so that the resulting replica pattern exhibits a polygonal shape.

[0312] At this time, in step (1), the ‘distance between electrodes’ means the distance between the upper electrode and the lower electrode.

[0313] In addition, in step (1), the ‘sufficiently small distance between electrodes’ generally means the filling ratio (= thickness of the applied polymer film / distance between electrodes), and 0.5 or more is appropriate.

[0314] In addition, the 'additional surface structure' in step (2) means a structure formed by a secondary electrohydraulic instability induced after the primary electrohydraulic instability, and includes the step in which the secondary electrohydraulic instability is induced in (2).

[0315] Additionally, in step (3), the replica structure formed by the secondary instability exhibits a shape opposite to that of the master pattern, implying that the final surface structure must be a polygon.

[0316] At this time, the 'unique edge' in the above (3) means a polygonal corner feature formed according to a specific flow of a polymer fluid, and is given in the form of a round or angular straight line.

[0317] In addition, the present invention essentially includes the following steps: (4) a step in which the unique edge is selectively controlled by experimental parameters involved in inducing electrohydraulic instability.

[0318]

[0319] Hereinafter, with reference to drawings 13 to 23, a large-area patterning method using secondary electrohydraulic instability of the present invention is described and demonstrated.

[0320] Figure 13 is a result showing a pattern replication method by electrohydraulic instability, and more specifically, a replication process by secondary instability induced after primary instability.

[0321] Referring to FIG. 13, in the present invention, the 'secondary electrohydraulic instability' or 'secondary instability' is distinguished from the first electrohydraulic instability that is induced first in time in the protruding region, and is defined as the electrohydraulic instability that is induced in the region below the non-protruding region after the first electrohydraulic instability occurs.

[0322] In the present invention, the above-mentioned 'electrohydraulic instability' is defined as a competitive relationship between the deformation of the thin film surface structure due to electrostatic pressure and the Laplace pressure that stabilizes it, and at this time, it necessarily implies a surface structure deformation process over time in order to lower the free energy inside the system.

[0323] In general, the primary instability induced under the protrusion of the master pattern causes the growth of a structure having the same shape as the master pattern, and the available master pattern is suitably a surface structure composed of alternating protrusions and non-protrusions, and the ratio of the size of the protrusions to the size of the non-protrusions is suitably 1:2 or less, but this does not limit the scope of the present invention.

[0324] Additionally, secondary electrohydraulic instabilities occurring below the non-protruding region pull the polymer fluid upward toward the mask pattern to fill the non-protruding region, resulting in the formation of secondary replica structures different from the primary structure.

[0325] At this time, in order to effectively induce secondary instability, a 'high-speed control' method that rapidly increases the growth speed of the electrohydraulic structure is effective. In this invention, the reciprocal of the characteristic time, 1 / , which refers to the initial growth speed of the structure over the entire thin film surface, is used. A method was used to increase the relatively slow rate of secondary instability development by increasing .

[0326] Specifically mentioned above is as shown in Equation 1 below.

[0327] <Formula 1>

[0328]

[0329] In the above equation 1 is the viscosity of the fluid film, is the surface tension of the fluid film, is the permittivity of the fluid thin film, is the vacuum permittivity, U is the applied voltage, h0 is the dielectric (fluid thin film) thickness, and d is the distance between the two electrodes.

[0330] In the present invention, the above 1 / The increase can accelerate the growth of secondary structures, which were relatively slow, and help to form structures reproducibly in a short period of time.

[0331] Also, the ideal high 1 / The secondary instability-based structures formed at small inter-electrode distances are negative replicas of the master pattern in the opposite shape, yielding results similar to conventional nanoimprinting or molding techniques.

[0332] In the present invention, the 'secondary replication method' refers to a negative replication production process formed through the secondary electrohydraulic instability described above.

[0333]

[0334] In addition, Fig. 14 is an electron scanning microscope image showing a secondary replication method induced after the primary replication method, where the secondary structure grows on a plane to determine the final negative replication area.

[0335] Unlike conventional patterning methods that utilize capillary force or mechanical compression, this secondary replication method relies on the use of an electric field—more precisely, electrostatic pressure—that enables polymer fluid behavior even at a given distance. This process characteristic allows patterning even with uneven contact.

[0336] In detail, (1) the polymer fluid is pulled up to a predetermined distance according to the rapid growth rate to form a structure, and (2) at the same time, since the voltage applied between the two electrodes pulls the upper and lower electrodes due to the Coulomb force (electrostatic force), uniform contact can be achieved without a separate device.

[0337] At this time, in the above secondary replication method, the polymer fluid behavior occurs in three dimensions, and can be divided into (1) planar growth and (2) vertical growth.

[0338] (1), the secondary replica initially formed in Fig. 3 grows laterally, and the final replica size (area) is determined during this process. Furthermore, regarding (2), the vertical growth of the secondary structure toward the non-protruding portion determines the aspect ratio of the structure according to the Laplace pressure that stabilizes the surface.

[0339]

[0340] Figure 15 illustrates the planar growth of a structure in a secondary replication method.

[0341] At this time, in order to reduce the excess electrostatic energy stored in the capacitor, the secondary structure grows as if spreading out laterally on a plane.

[0342] The secondary structure formed at this time exhibits unique edges that are straight or sharp in shape from the plane edge.

[0343] The secondary structures resulting from the planar growth exhibit polygonal shapes, which can be explained by analyzing the unique edges appearing at the corners of the structures.

[0344]

[0345] Figure 16 illustrates two different aspects of polymer fluid behavior in a secondary replication mode.

[0346] Referring to Fig. 16, due to the nature of the master pattern consisting of alternating protrusions and non-protrusions, the planar behavior of the polymer fluid can be classified into two types: (a) the polymer fluid advances and moves in the area under the protrusions in a parallel state, or (b) the polymer fluid meets in the area under one protrusion in a non-parallel state.

[0347]

[0348] Figure 17 shows the results of a computer simulation of the flow behavior of a planar polymer fluid during a secondary replication process.

[0349] In Fig. 17, the case where the planar polymer fluid flows are not parallel to each other is called 'AC' (Armchair), and the case where the planar growth is parallel to each other is called 'ZZ' (Zigzag).

[0350] At this time, the edge characteristics of the structure change depending on whether the polymer fluid flows are parallel to each other or not in the planar growth of the secondary replication method, and as a result, a polygonal shape of the secondary pattern appears.

[0351]

[0352] Figure 18 is a result showing secondary structures that exhibit different unique edges.

[0353] At this time, the two different intrinsic edges can be explained by surface energy analysis, and in the case where the growth proceeds in a non-parallel state (AC), the reduction in electrostatic energy may be small when comparing before and after the formation of the intrinsic edges.

[0354] In this case, when the electrostatic energy inside the capacitor system is relatively small, that is, the applied electric field is relatively weak, the edge formed by the Laplace pressure appears to be rounded.

[0355] Additionally, in the case where the polymer fluid flows proceed parallel to each other in planar growth (ZZ), the reduction in electrostatic energy can be large when comparing before and after the formation of the unique edge.

[0356] In this case, when the electrostatic energy inside the capacitor system is relatively large, that is, when the applied electric field is relatively large and the influence of the Laplace pressure is small, the edge formed appears in the form of a straight line.

[0357]

[0358] Figure 19 shows the results of analysis of different unique edge formations.

[0359] Referring to Figure 19, the present invention indicates the ratio between the Laplace pressure and the electrostatic pressure. An analysis was conducted between the shape of the secondary replica structure and the shape of the secondary replica structure.

[0360] At this time, at are each as shown in Equation 2 below.

[0361] <Formula 2>

[0362]

[0363] In the above formula is the characteristic wavelength, at is as shown in Equation 3 below.

[0364] <Formula 3>

[0365]

[0366] In the above formula is an arbitrary physical quantity for scaling.

[0367] Above In the growth of electrohydraulic structures, the relationship between the electrostatic pressure that induces structure growth and the Laplace pressure that hinders it is shown.

[0368] If it is less than 1, the influence of electrostatic pressure increases, and if it is greater than 1, the influence of electrostatic pressure decreases.

[0369] Additionally, simulation and experimental results show that in the secondary replication process As becomes smaller, the structure exhibits sharp, straight edges (ZZ), and as becomes larger, the structure exhibits rounded edges (AC).

[0370] In addition, in the case of angular straight edges in the plane structure growth, it is advantageous for large-area formation because the surrounding polymer fluid moves together to determine the structure area.

[0371]

[0372] Figure 20 is a graph showing the growth rate of the electrohydraulic structure. As the number of particles increases, the secondary structure area also tends to increase.

[0373] Figure 20 confirms that it is difficult to achieve uniform large-area replication simply by increasing the growth rate.

[0374] At this time, even if the structure grows rapidly in the secondary replication process, in the case of a replication process that forms rounded corners, the pattern area increases, but the uniformity of the replication pattern deteriorates.

[0375] On the other hand, referring to Fig. 21, in the case of a replication process that forms an angular straight edge, not only can the pattern area increase but also the pattern uniformity can be improved.

[0376] At this time, in the case of angular straight edges in the plane structure growth, it can be advantageous for large-area formation because the surrounding polymer fluid moves together to determine the structure area.

[0377] Additionally, the method of promoting the high growth rate and angular straight edge induction of the secondary electrohydraulic structures as described above can achieve uniform large-area patterning in the secondary replication method.

[0378] According to the present invention, the increase due to the high electric field not only increases the growth rate but also promotes the polymer fluid flow for forming angled, straight edges, so that uniform large-area patterning can be achieved.

[0379]

[0380] Referring to Figure 23, the results show that uniform large-area patterning can be achieved even with non-uniform contact because the Coulomb force due to the fast growth rate of the structure and the high electric field pulls the two electrodes together.

[0381] In the present invention, 'uneven contact' means that the distance between electrodes (i.e., the thickness of the air layer between the upper and lower electrodes) in the electrohydraulic patterning process is not distributed equally across the entire thin film surface on the lower electrode.

[0382]

[0383] Therefore, effective control of secondary electrohydraulic instability can easily form negative replicas through structure growth in the non-protruding region.

[0384] Additionally, since the applied electric field electrostatically attracts the two electrodes (master mold and substrate), uniform contact can be achieved without separate equipment or systems.

[0385] Therefore, according to the present invention, large-area patterning can be made possible even with uneven contact.

[0386] At this time, the planar growth of the secondary structure exhibits unique edges according to the master pattern, and active control of specific unique edges can improve the uniformity of the replicated structure.

[0387] In addition, the above achievements can be applied to various technological and industrial fields such as semiconductor devices, high-sensitivity sensors, energy storage-generation devices, meta surfaces, and optical devices that require micro- / nano-level microstructures.

[0388]

[0389] A patterned polymer film according to another embodiment of the present invention is described.

[0390] A patterned polymer film according to another embodiment of the present invention is characterized in that it is manufactured using a large-area patterning method.

[0391]

[0392] Hereinafter, the present invention will be described in more detail through manufacturing examples and experimental examples. These manufacturing examples and experimental examples are intended solely to illustrate the present invention, and the scope of the present invention is not limited by these manufacturing examples and experimental examples.

[0393]

[0394] Manufacturing Example 1: Manufacturing of a biosurface structure replica

[0395] First, a capacitor was prepared, which included a substrate having a 100 nm thick liquid polymer layer formed of a thermoplastic polymer material as a lower electrode and a mask pattern formed of a bio-surface material positioned spaced apart on the upper portion of the substrate as an upper electrode.

[0396] At this time, the above-mentioned distance is at least 1 μm.

[0397] Next, a voltage of 0.5 kV is applied to the electrodes of the capacitor, and 10 8 A negative replica was manufactured by generating an electric field of V / m intensity to induce secondary electrohydraulic instability and forming a liquid polymer layer in a negative pattern.

[0398] Next, a metal material composed of 10 nm was applied to the surface of the negative replica to manufacture a negative replica having a metal layer formed thereon.

[0399] Next, a capacitor including a mask mold consisting of a substrate having a liquid polymer layer formed as a lower electrode and a negative replica having a metal layer formed spaced apart from the upper portion of the substrate as an upper electrode is prepared, and a voltage of 0.5 kV is applied to the electrodes of the capacitor to 10 8A three-dimensional biosurface structure replica in a positive shape was manufactured by generating an electric field of V / m intensity to induce secondary electrohydraulic instability and forming a liquid polymer layer in a negative pattern.

[0400]

[0401] Manufacturing Example 2: Patterned polymer film manufactured using a large-area patterning method

[0402] First, a capacitor was prepared, which included a substrate having a 100 nm thick liquid polymer layer formed of a thermoplastic polymer material as a lower electrode and a mask pattern formed of a bio-surface material spaced apart on the upper portion of the substrate as an upper electrode.

[0403] At this time, the above-mentioned distance is 1 μm.

[0404] Next, a voltage of 0.5 kV was applied to the electrodes of the capacitor, and 10 8 A secondary electro-hydraulic instability was generated by generating an electric field of V / m, thereby forming a liquid polymer layer in an engraved pattern.

[0405]

[0406] Experimental Example 1: Experiment in Fig. 4 (Confirming the method of replicating biosurface structures by secondary instability)

[0407] Figure 4 is a schematic diagram and scanning electron microscope image illustrating a method of replicating a biosurface structure by secondary instability.

[0408] Figure 4 uses cicada wings (Oncotympana fuscata) as a biosurface structure target.

[0409] Additionally, the collected cicada wings were washed in acetone, ethanol, and deionized water for 10 minutes each.

[0410] Afterwards, the cicada wings were carefully cut to obtain wing membranes with an area of ​​2×12 mm².

[0411] In addition, PMMA (poly(methyl methacrylate)) with a thickness of less than 100 nm was applied on a silicon substrate, and the cicada wing membrane was placed and fixed in a heat treatment environment of 120 °C for about 3 minutes.

[0412] At this time, PVA (polyvinyl alcohol) was added to deionized water and heated and stirred at 95 °C to produce a solution of 2.5 to 7 wt%.

[0413] Afterwards, the PVA solution was applied onto the substrate using the spin coating technique to form a PVA thin film with a thickness of approximately 300 to 800 nm.

[0414] At this time, the upper electrode where the cicada wings are located was placed on the PVA thin film, and then voltage was applied to perform the electrohydraulic control technique.

[0415] At this time, the structure growth rate was changed by using the decrease in PVA viscosity according to the increase in applied voltage and temperature.

[0416] In this example, 1 / To express the structure growth rate by defining it as 53.71 was used.

[0417] At 2.44, nanohole structures, which are negative replicas of cicada wing nanostructures, were observed.

[0418] since As the number of electrohydraulic secondary replications increases, the planar growth can be promoted.

[0419] especially, At 6.60, cicada wing nanostructure negative replicas can be replicated across the entire surface.

[0420]

[0421] Experimental Example 2: Experiment of Fig. 6 (using a negative replica coated with a metal film as a master mold)

[0422] Figure 6 shows the result of producing the original biosurface structure using a negative replica coated with a metal thin film as a master mold.

[0423] The negative replica obtained in Experimental Example 1 was made by applying a 10 nm thick platinum thin film using the sputtering technique and then using it as the upper electrode to perform the electrohydraulic secondary replication method.

[0424] At this time, PS (polystyrene) was added to toluene, heated and stirred at 80 °C, and a solution of 3 to 8 wt% was prepared.

[0425] Afterwards, the PS solution was applied onto the substrate using the spin coating technique to produce a thin film with a thickness of approximately 200 to 800 nm.

[0426] At this time, the formed thin film was heat-treated at 150 °C for 30 minutes to evaporate the remaining solvent.

[0427] At this time, the heat treatment temperature was changed from 100 to 220 °C and other parameters were fixed (applied voltage: 0.6 kV, thin film thickness: 600 nm, process time: 10 minutes) to change the process viscosity.

[0428] At this time With the pressure fixed at 354813 Pa·s, The growth trend of the planar structure according to the change of (3.44~6.91) was observed.

[0429] When 13.22, the area of ​​the replica structure was confirmed to be similar to the original wing membrane area (2×12 mm²).

[0430] At this time, When the number is 25 or more, the area of ​​the replica structure becomes larger, reaching 1 ㎠.

[0431]

[0432] Experimental Example 3: Experiment in Fig. 7 (observing the vertical growth trend of the replica structure)

[0433] Figure 7 shows the results of controlling the vertical growth of the cicada wing structure as the electric field strength increases.

[0434] Referring to Fig. 7, the vertical growth trend of the replica structure according to the increase in electric field strength was observed under the same experimental conditions as Experimental Examples 1 and 2.

[0435] To represent the electric field strength was used ( )

[0436]

[0437] Above When the value was 154.39, replication characteristics began to be observed.

[0438] However, the aspect ratio can be confirmed to be less than 0.3 because the electric field strength is not sufficient.

[0439] Also, the above When the length was 241.23, the aspect ratio was almost 1, When it was 347.38, it was 1.67~2.33.

[0440] Also, perfect replication is It can be confirmed when it is 472.82.

[0441]

[0442] Experimental Example 4: Experiments in Figs. 9 and 10 (using rose petals as biological surface structure objects)

[0443] Figure 9 shows the results of replicating the micro-nano hybrid structure on the surface of a rose petal using an electrohydraulic secondary replication method.

[0444] Figure 10 is an image showing a comparison of vertical replication fidelity according to an increase in applied voltage (electric field) intensity.

[0445] Rose petals (Rosehybrid tea petals) were used as biosurface structure targets.

[0446] Rose petals were washed in acetone, ethanol, deionized water, etc. for 10 minutes each, and tissues with an area of ​​25×25 mm² were obtained.

[0447] Additionally, PDMS (polydimethylsiloxane) was mixed with a PDMS base and a PDMS curing agent in a ratio of 10:1, and then air bubbles were removed under vacuum.

[0448] PDMS with a thickness of less than 200 nm was applied onto a silicon substrate, and the rose petal tissue was placed and fixed. PDMS was then applied onto the substrate to form a thin film with a thickness of approximately 40 μm.

[0449] The upper electrode, where the rose petals are located, was placed on the PDMS thin film, and a voltage was applied to perform the electrohydraulic control technique.

[0450] At this time, in this embodiment according to the applied voltage, 1 / 47.84 s -1 To express the structure growth rate by defining was used.

[0451] It was confirmed that the negative replica of the rose petal micro-nano hybrid structure was replicated over the entire surface at 7.78.

[0452] The engraved replica obtained in this way was then coated with a 10 nm thick platinum film using the sputtering technique and then used as an upper electrode to perform a secondary electrohydraulic replication method.

[0453] PVDF (polyvinylidene fluoride) was added to the organic solvent DMF (dimethylformamide), heated and stirred at 100 °C, and a 10-15 wt% solution was prepared.

[0454] Afterwards, a PVDF solution was applied onto the substrate using the drop casting technique to produce a thin film with a thickness of approximately 35 to 45 μm.

[0455] The thin film formed at this time was heat treated at 100 °C for 60 minutes to evaporate the remaining solvent.

[0456] In addition, the vertical growth trend of the replicated structure according to the increase in electric field intensity was observed by changing the applied voltage from 0.4 kV to 1.3 kV and fixing other parameters (film thickness: 35–45 μm, process time: 10 min).

[0457] Additionally, the structure starts replicating at 0.4 kV, and the vertical replication fidelity can be improved with increasing applied voltage.

[0458] Additionally, according to Fig. 10b, it can be seen that the biosurface structure is replicated identically at 1.3 kV.

[0459]

[0460] Experimental Example 5: Experiment of Fig. 11 (replication of rose petal surface)

[0461] Figure 11 shows the results of observing the trend in the replication area of ​​a rose petal hybrid structure according to plane growth.

[0462] An attempt was made to replicate the surface of rose petals under the same conditions as in Experimental Example 4 above.

[0463] At this time, the structure area trend according to the plane growth was observed.

[0464] Additionally, it was confirmed that when no applied voltage was applied, almost no replication was performed, but as the applied voltage increased, the entire structure area was replicated.

[0465] The above figure 11 shows the area increase trend according to plane growth.

[0466]

[0467] Experimental Example 6: Experiment of Fig. 13

[0468] Figure 13 is a schematic diagram and scanning electron microscope image showing the growth of positive replicas due to primary instability and the growth of negative replicas due to secondary instability.

[0469] A solution of approximately 3.0 w% polystyrene diluted in toluene was applied onto a substrate using a spin coating technique to form a polystyrene thin film with a thickness of approximately 200 nm.

[0470] At this time, a master pattern in which 150 nm-sized cylinders are arranged in a regular hexagon was attached to the upper electrode.

[0471] Afterwards, electrohydraulic patterning was performed by applying a voltage of 80 V for 20 minutes while maintaining the fill ratio (= film thickness / distance between electrodes) at 0.34.

[0472] Electrohydraulic patterning was performed under the same conditions while maintaining the fill ratio at 0.73.

[0473] Figure 13c shows the experimental results at this time. When the fill ratio is 0.34, the primary structure forms a positive replica, and it can be confirmed that the distance between the electrodes is sufficiently large that the secondary replication method does not proceed.

[0474] On the other hand, when the fill ratio is 0.73, the distance between the electrodes is sufficiently small that a negative replica can be formed by secondary replication.

[0475] Through this, it can be seen that negative replication by secondary instability is induced only when the distance between electrodes is sufficiently small, as illustrated in Fig. 2b.

[0476]

[0477] Experimental Example 7: Experiment of Fig. 15

[0478] Figure 15 is a schematic diagram showing the planar growth in the structure replication method by secondary instability.

[0479] In Fig. 15, the filling ratio was maintained at 0.73, and a voltage of 30 V was applied for 1 to 30 minutes.

[0480] At this time, it can be seen that some negative replicas (nanohole patterns) were initially formed, but they were very small in size (1 minute).

[0481] However, as the process time increases, the structure may grow on the plane, increasing its area.

[0482] Through this, it can be confirmed that the plane structure growth is achieved in the secondary replication method.

[0483]

[0484] Experimental Example 8: Experiment of Fig. 16

[0485] Figure 16 is a schematic diagram showing a comparison of the behavior of polymer fluids forming negative patterns in a secondary replication method.

[0486] Electrohydraulic patterning can be performed in the range of 1 to 4 to observe that the negative replicas formed by secondary instability induction exhibit unique edges.

[0487] Figure 16 can illustrate the surface structure of the secondary replication pattern confirmed through scanning electron microscope observation.

[0488] Through the above figure 16, it can be confirmed that two different corners are formed to represent a polygonal shape.

[0489]

[0490] Experimental Example 9: Experiment of Fig. 19

[0491] Figure 19 shows the results of analysis of different unique edge formations.

[0492] This experiment was conducted to analyze the unique edge and parameter dependence observed in the secondary replica structures of polygonal shape. It quantitatively represents the competition between electrostatic pressure and Laplace pressure. Electrohydraulic patterning was performed by varying the value within the range of 0.1 to 10.

[0493] The results of the above experiment are shown in [Figure 8]. When the value is 4.01, a round-shaped structure can be observed as the rounded corners are dominant.

[0494] When the value is 0.879, the rounded and sharp corners can be appropriately combined to represent a polygonal shape.

[0495] At this time, When the angle is 0.149, a hexagonal structure can be produced as the sharp corners are dominant.

[0496]

[0497] Experimental Example 10: Experiment of Fig. 22

[0498] Figure 22 shows experimental results showing that, despite the high growth rate, the planar structure growth forms angular and straight edges (ZZ).

[0499] Electrohydraulic patterning was performed by intensively increasing the electric field intensity to selectively control the angular straight edges.

[0500] At this time, E0 / E quantitatively represents the applied electric field p is controlled from 1 to 20.1. As the electric field increases, the structure growth rate also increases, where E0 / E p increased from 0.28 to 13701.1.

[0501] The above figure 22 shows the results of the experiment.

[0502] Ep / E0 and As the angle increases, the growth of angular and straight edges is promoted, and at the same time, the growth rate also increases rapidly, enabling the replication of uniform large-area patterns.

[0503]

[0504] Experimental Example 11: Experiment of Fig. 23

[0505] Figure 23 is a result of the present invention that achieves uniform large-area patterning even with uneven contact.

[0506] Experiments are conducted to demonstrate that the present invention allows uniform large-area patterning even with uneven contact.

[0507] At this time, the master pattern used can be used without a support device for the distance between the electrodes.

[0508] At this time, a small pressure of 0.00367 kgf / ㎠ can be applied on the upper electrode to ensure uneven contact / uneven distance between electrodes.

[0509] In the above environment, the distance between electrodes is given as approximately 0 to 2000 nm.

[0510] The above applied voltage can be applied differently, such as 0.3 kV and 0.6 kV.

[0511] When the above applied voltage is 0.3 kV, the distance between the electrodes is given as 1000 or more at 0 to 800 nm.

[0512] At this time, the uniformity of the pattern formed may be low due to insufficient growth rate.

[0513] On the other hand, when the applied voltage is 0.6 kV, the effective inter-electrode distance range can increase to 1800 nm.

[0514] Therefore, in this case, large-area patterning can be achieved even with uneven contact.

[0515] At the same time, uniformity can also be improved due to high electric field strength.

Claims

1. A step of preparing a capacitor including a substrate having a liquid polymer layer formed as a lower electrode and a mask pattern positioned spaced apart from the upper portion of the substrate as an upper electrode; A step of applying current to the electrodes of the capacitor to generate an electric field to cause secondary electrohydraulic instability to form a liquid polymer layer in an engraved pattern to manufacture an engraved replica; A step of manufacturing an intaglio replica by applying a metal material to the surface of the intaglio replica to form a metal layer; and A method for manufacturing a replica of a biological surface structure, comprising the steps of preparing a capacitor including a mask mold comprising a substrate having a liquid polymer layer formed as a lower electrode and a negative replica having a metal layer formed spaced apart from the upper portion of the substrate as an upper electrode, applying current to an electrode of the capacitor to generate an electric field to generate secondary electrohydraulic instability to form a liquid polymer layer in a negative pattern, thereby manufacturing a three-dimensional replica of a biological surface structure in a positive shape.

2. In paragraph 1, In the step of preparing the above capacitor, A method for manufacturing a replica of a biosurface structure, characterized in that the above mask pattern is a biosurface structure.

3. In paragraph 1, In the step of preparing the above capacitor, A method for manufacturing a replica of a biological surface structure, characterized in that the above mask pattern has a rough structure composed of alternating protrusions and non-protrusions.

4. In paragraph 1, In the step of preparing the above capacitor, A method for manufacturing a replica of a biological surface structure, characterized in that the gap between the substrate on which the polymer layer is formed and the mask pattern is 0 μm to 4 μm.

5. In paragraph 1, In the step of preparing the above capacitor, A method for manufacturing a replica of a biological surface structure, characterized in that the thickness of the liquid polymer layer is 150 nm to 2000 nm.

6. In paragraph 1, A method for manufacturing a biosurface structure replica, characterized in that the method for manufacturing a biosurface structure replica is performed at a temperature higher than the glass transition temperature of a liquid polymer material.

7. In paragraph 1, In the step of manufacturing the above engraved replica, A method for manufacturing a replica of a biological surface structure, characterized in that the voltage applied to the electrode is 0.5 kV to 1.8 kV.

8. In paragraph 1, In the step of manufacturing the above engraved replica, The electric field strength applied to the above capacitor is 10 8 A method for manufacturing a replica of a biological surface structure characterized by having a density of V / m or greater.

9. In paragraph 1, In the step of manufacturing the above engraved replica, The initial growth rate for forming the above negative pattern is 10 2 s -1 10 inland 7 s -1 A method for manufacturing a replica of a biological surface structure, characterized by:

10. In paragraph 1, In the step of manufacturing the above engraved replica, The initial growth rate is given by the following equation 1 ( ) is characterized by following the reciprocal of: <Formula 1> In the above equation 1 is the viscosity of the fluid film, is the surface tension of the fluid film, is the permittivity of the fluid thin film, is the vacuum permittivity, U is the applied voltage, h0 is the dielectric (fluid thin film) thickness, and d is the distance between the two electrodes.

11. In paragraph 1, In the step of manufacturing an engraved replica on which the above metal layer is formed, A method for manufacturing a replica of a biosurface structure, characterized in that the metal layer is composed of an electrically conductive metal material.

12. In paragraph 1, In the step of manufacturing an engraved replica on which the above metal layer is formed, A method for manufacturing a replica of a biosurface structure, characterized in that the thickness of the metal layer is 10 nm to 20 nm.

13. In paragraph 1, In the step of manufacturing the above three-dimensional bio-surface structure replica, The growth rate of the above 3D biosurface structure replica is expressed by the following equation 1 ( ) is characterized by following the reciprocal of: <Formula 1> In the above equation 1 is the viscosity of the fluid film, is the surface tension of the fluid film, is the permittivity of the fluid thin film, is the vacuum permittivity, U is the applied voltage, h0 is the dielectric (fluid thin film) thickness, and d is the distance between the two electrodes.

14. A step of preparing a capacitor including a substrate having a liquid polymer layer formed on the lower portion and a mask pattern positioned spaced apart from the upper portion of the substrate; and A large-area patterning method characterized by including a step of applying current to the electrode of the capacitor to generate an electric field to cause secondary electrohydraulic instability and form a liquid polymer layer into an intaglio pattern.

15. In paragraph 1, A large-area patterning method characterized in that the lower electrode of the above capacitor is a substrate and the upper electrode is a mask pattern.

16. In paragraph 1, In the step of preparing the above capacitor, A large-area patterning method characterized in that the above mask pattern has a rough structure composed of alternating protrusions and non-protrusions.

17. In paragraph 1, In the step of preparing the above capacitor, A large-area patterning method, characterized in that the gap between the substrate on which the polymer layer is formed and the mask pattern is 200 nm to 2 μm.

18. In paragraph 1, In the step of preparing the above capacitor, A large-area patterning method, characterized in that the thickness of the liquid polymer layer is 150 nm to 2000 nm.

19. In paragraph 1, In the step of forming the above liquid polymer layer into an engraved pattern, A large-area patterning method characterized in that it is performed in a temperature range of 100°C to 180°C.

20. In paragraph 1, In the step of forming the above liquid polymer layer into an engraved pattern, A large-area patterning method characterized in that the applied voltage generates a high-voltage pulse of 0.2 kV to 2.1 kV.

21. In paragraph 1, In the step of forming the above liquid polymer layer into an engraved pattern, The permitted electric field strength is 10 8 A large-area patterning method characterized by having a V / m or greater.

22. In paragraph 1, In the step of forming the above liquid polymer layer into an engraved pattern, The initial growth rate for the formation of the above negative pattern is 3.57 s -1 3.5×10 5 s -1 A large-area patterning method characterized by:

23. In paragraph 1, In the step of forming the above liquid polymer layer into an engraved pattern, A large-area patterning method characterized in that the initial growth rate is the reciprocal of Equation 1 below: <Formula 1> In the above equation 1 is the viscosity of the fluid film, is the surface tension of the fluid film, is the permittivity of the fluid thin film, is the vacuum permittivity, U is the applied voltage, h0 is the dielectric (fluid thin film) thickness, and d is the distance between the two electrodes.

24. In paragraph 1, In the step of forming the above liquid polymer layer into an engraved pattern, A large-area patterning method characterized in that the overall shape and size of a patterned substrate are controlled through unique edge analysis.

25. In paragraph 11, In the step of forming the above liquid polymer layer into an engraved pattern, A large-area patterning method characterized in that the edge of a substrate on which a pattern is formed by the above-mentioned unique edge analysis is adjusted to a straight or round shape.

26. In paragraph 1, In the step of forming the above liquid polymer layer into an engraved pattern, The above unique edge analysis shows that the electrostatic pressure that induces the growth of the structure ( ) and the Laplace pressure that interferes with it ( )at / It means value, and the above / If the value is less than or equal to 1, it forms a sharp corner, / A large-area patterning method characterized by forming rounded corners when the value exceeds 1: Above The following equation is 2, is the following equation 3, <Formula 2> And, <Formula 3> and, Above is the viscosity of the fluid film, is the surface tension of the fluid film, is the permittivity of the fluid thin film, is the vacuum permittivity, U is the applied voltage, h0 is the dielectric (fluid thin film) thickness, and d is the distance between the two electrodes.

27. A patterned polymer film characterized by being manufactured using the large-area patterning method of paragraph 1.

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