KR20110078843A - A substrate for inhibiting formation of biofilm and a method for preparing the same - Google Patents

Abstract

PURPOSE: A substrate for preventing a bio film from becoming formed and a method of manufacturing the substrate are provided to prevent contamination and corrosion due to microorganism by fundamentally preventing a bio film from becoming formed on the surface. CONSTITUTION: A substrate for preventing a bio film from becoming formed comprises a substrate, a plurality grooves and a porous structure. The grooves are formed on the top of the substrate. The porous structure is formed on the upper front and the grooves of the substrate. The porous structure has a diameter of 0.1μm~5μm, an interval of 0.1μm~1μm a depth of 1μm~1000μm.

Description

A substrate for inhibiting formation of biofilm and a method for preparing the same

The present invention relates to a substrate for preventing biofilm formation, and more particularly, to a substrate for preventing biofilm formation, including a substrate, a plurality of grooves formed on the substrate, and a porous structure formed on the front surface and the groove on the substrate. It relates to a manufacturing method and a method for preventing surface corrosion by microorganisms using the substrate.

Biofilms are generally referred to as biofilms as structures formed by microorganisms that adhere to and proliferate on the surface of materials in an aqueous system. Such biofilm formation causes a risk by microorganisms and thus causes problems in various industries. For example, when the biofilm formed on the factory pipe is peeled off and mixed with the product of the factory, not only contamination of the product may occur, but also when the product is food, it may act as a fatal risk factor for the human body. Biofilm on the surface of the heat exchanger also reduces the heat transfer efficiency. Furthermore, if biofilm is formed on the surface of a structure, such as a metal surface, it may cause corrosion of the metal and decay of the facility. In particular, damages caused by corrosion of materials such as various metals and concrete are not only inconvenient, but also costly for reconstruction, which is causing economic difficulties.

The development of technology for solving such problems is recognized as a technical problem in various fields such as environment, water treatment, health and medical field, and various researches have been conducted for several decades. Once formed, the biofilm is not completely removed by conventional physical methods and chemical methods such as the injection of polymer drugs. Thus, a satisfactory solution for contamination prevention and control by biofilm has not been developed until now. There is a situation.

As a method for reducing the corrosion and contamination of the surface of the structure by the biofilm has been devised a method for inhibiting or preventing the growth of the biofilm on the corrosion-sensitive material (for example, metal). For example, in order to prevent the growth of microorganisms constituting the biofilm, various methods such as pH control, redox potential control, inorganic coating, cathodic protection, and biocide application are performed, but protective coatings such as paints and epoxies are used. They are excessively expensive to apply and maintain, making them impossible to use as effective anti-biofilm formulations.

Other techniques related to the prevention of biofilms include: 1) inhibiting biofilm formation by coating surfaces using microorganisms or specific chemicals, or 2) decomposing biofilms formed using specific organisms or compounds. , 3) There is a method of inhibiting or disturbing the growth of the microorganisms forming the biofilm, but until now, there has been no report on the technology for preventing the formation of the biofilm by applying a specific form to the surface itself.

Therefore, the inventors of the present invention can prevent the production of biofilms by coating a specific chemical or microorganism or by treating the various substances without modifying the surface of the surface. A substrate comprising the structure produced by the method was fabricated and the present invention was completed.

An object of the present invention is a substrate; A plurality of grooves formed on the substrate; And a porous structure formed on the upper front surface and the groove of the substrate.

Another object of the present invention is to form a groove on the substrate; And (b) forming a porous structure on the upper front side and the groove of the substrate.

Still another object of the present invention is to provide a method of preventing biofilm formation by using the biofilm formation preventing substrate as a surface.

As an aspect for achieving the above object the present invention is a substrate; A plurality of grooves formed on the substrate; And a porous structure formed on an upper front surface of the substrate and the groove. Preferably, the substrate including the groove and the porous structure of the present invention can form a microstructure having a superhydrophobic surface due to the above structural features, and can have a nano-micro multi-scale composite structure, As a result, biofilm formation by the growth and proliferation of microorganisms can be prevented or suppressed.

The term "substrate" of the present invention is not limited as long as it is a material capable of forming the grooves and porous structures of the present invention, and is a structure having a material or material capable of preventing the formation of biofilm by treating the surface with the above structure. Is not limited. Preferably, examples of the material include metal, polymer, glass, and the like, but the types of materials to which the surface structure of the present invention is applicable are not limited by the above examples. Preferably, the substrate may be made of stainless steel, and in the preferred embodiment of the present invention, the structure of the present invention is formed using stainless steel (SUS304), which is variously used in daily life such as a water pipe, and a substrate including the structure. It was confirmed that this biofilm formation can be suppressed (Example 4).

Preferably, the "groove" of the present invention means an uneven structure formed on the surface of the substrate, the diameter, spacing and depth of the groove can be appropriately adjusted by those skilled in the art as needed. This range is preferably set in the direction of suppressing the growth of microorganisms constituting the biofilm. In addition, the size of the grooves applied on the substrate may be homogeneous or not homogeneous, and it is preferable to form grooves of various sizes and structures as long as the formation of the biofilm can be suppressed. It is preferable that the interval of the grooves is 0.1 mm to 10 mm, and the depth of the grooves is 3 μm to 1 mm. In the case of the diameter of the groove, it is important to set such that the microorganism does not grow by penetrating the inside of the groove, and therefore, the lower diameter is preferably set to the size of the target microorganism to be prevented from forming the biofilm. In general, the size of the microorganisms known to form a biofilm is 0.1㎛ to 10㎛, and the size of the microorganisms are known to be 1㎛ to 3㎛ in many microorganisms, it is recommended that those skilled in the art to appropriately control the diameter of the lower Is preferred.

By "porous structure" of the present invention is meant a form present on the surface of the substrate, the porous structure may be formed on all or part of the surface as required by those skilled in the art. Preferably, the porous structure is not limited in the form and number to the extent that the various microorganisms known to form the biofilm can be prevented or inhibited from adhering to and proliferating on the surface, and the porous structure has a regular distribution or irregularity such as a groove. It may be configured in any form such as distribution. Such a structure can be formed into a structure in which substances such as water droplets required for growth conditions of microorganisms and other microorganisms cannot be stagnated. Preferably the diameter of the porous structure may be 0.1㎛ to 5㎛, the spacing between the porous structure is 0.1㎛ to 1㎛, the depth may be formed in the range of 1㎛ to 1000㎛.

As such, the porous structure formed on the entire surface including the substrate, the grooves formed on the surface of the substrate, and the grooves prevents water droplets necessary for the survival of the microorganisms from adhering to the substrate, that is, the microstructure having the superhydrophobic surface. By inducing them to form, ultimately, the microorganisms themselves can attach to, grow, and proliferate on the surface of the substrate.

In another aspect, the present invention provides a method for forming a semiconductor device, comprising the steps of: (a) forming a groove on top of a substrate; And (b) forming a porous structure on the upper front surface and the groove of the substrate.

The process of manufacturing a substrate including the structure of the present invention may be divided into a step of forming a groove and a step of forming a porous structure, and the two steps may be performed simultaneously or sequentially according to the choice of those skilled in the art. .

In addition, the step of forming the groove and the step of forming the porous structure may be used without limitation methods commonly used in the art, preferably the groove and the porous structure may be performed by an etching method. Etching method can also be etched according to the conventional methods used in the art according to the material and material properties of the substrate, the groove and the porous structure of the present invention, if necessary to form a microstructure in μm unit However, there may be a difficulty in forming by a general etching method. Accordingly, the present inventors have come to form the desired porous structure using chemical etching, electrochemical etching, discharge processing, or electrolytic processing among various methods known in the art to form the porous structure of the present invention.

Among the above methods, the chemical etching method is a method of etching using various etching solutions, it is possible to prepare an etching solution of a suitable composition according to the purpose and the needs of those skilled in the art. Electrochemical etching is a method performed in the embodiments of the present specification, the discharge machining (EDM (Electro-Discharge Machining)) is a method performed by using a physical, mechanical or electrical action that occurs when a discharge between the two electrodes. Such electric discharge machining can be performed irrespective of the strength of the material, and is a method of easily processing complex shapes such as planes and solids. In addition, in the case of surface processing, the electric discharge machining method may process up to 0.1 μm to 0.2 μm max, and may achieve an object that cannot be achieved by other processing methods in that there is no surface deterioration by heat. Finally, electro-chemical machining (ECM) produces a metal oxide film, which is an anode product, which hinders the progress of electrochemical dissolution of a metal material. In electrolytic processing, if a tool made in the shape to be processed is used as a cathode, the material is used as an anode, and both of them are immersed in an electrolyte solution and the current is passed through, the material is processed like the surface shape of the cathode. It can be used for processing such hard cemented carbide, heat resistant steel, and the like. In addition, since the tool does not rotate, it can be used for drilling of special shape, not circular. If electrolytic machining is used, the cathode shall be machined to mirror and sufficient current density shall be maintained between the tool anode and the workpiece anode. The substrate of the present invention can be carried out as described above to form the desired groove and porous structure.

The present inventors have performed various methods as well as the methods described above to apply the structure of the grooves and the porous structure to the substrate, while trying to develop the optimal method to perform the photo lithgraphy and electrochemical fabrication (ECF) method On the other hand, it was confirmed that the target structure in the present invention can be achieved in the case of etching the substrate using the FeCl ₃ solution again formed the groove structure produced by the above method. In addition, as a result of applying the biofilm-forming microorganisms to the substrate prepared by the method, it was confirmed that the biofilm can be effectively suppressed.

In addition, it is possible to change the contact angle of the porous structure according to the needs of those skilled in the art, or according to the type of biofilm to be prevented, and at this time, a variety of methods for changing the contact angle, including a method of treating with an etchant may be performed. The type and concentration of the etchant used may be determined by those skilled in the art according to the purpose, and the time and number of times of exposure to the etchant may also be determined by conventional methods. The inventors have found that when the time and number of times exposed to the etchant increases, the contact angle of the porous structure can be increased. In addition, the present inventors have made a lot of experiments, and as a result of diligent efforts, it was confirmed that as the contact angle increases, microbial adhesion is reduced, as a result that the biofilm can be further suppressed.

As another aspect, the present invention relates to a method for preventing biofilm formation by using the substrate for preventing biofilm formation as a surface.

When the substrate including the groove and the porous structure of the present invention is used, contamination and corrosion by various microorganisms known to form a biofilm can be suppressed or prevented.

The microorganisms forming the biofilm that can be suppressed in the present invention include all the biofilm forming microorganisms known in the art, for example, Pseudomonas aeruginosa, Staphylococcus epidermidis , Delicia pulchra, methodill resistant staphylococcus aureus, lygonella pneumophila, Serratia, Vibrio Fischeri, Vibrio Harveyi, Clep Microorganisms such as Klebsiella Oxytica and Enterobacter Cloacae, enterobacteria including Escherichia coli, fungi such as Candida albicans, and as marine organisms, Barnacles Emphitreat, Balanus Emphitreat Communities, Balanus Elegantidegatus, Megavalanus Antilentis, Ktamalus Laensis, Ktamalus withersi, and La Paz Anatifera, etc., Birds (diatoms: Dunaliella, Nitzshia, Skeletoneema, Caeseroseus, and Dunaliella terthiorecta, Skeletato themes) Costatium species), mottled marsupials, tubular monopods, red algae, molluscs, shellfish, red and brown lichens, ascidian, cocci, mussels, hydroworms, macrophages, oysters, ulba, Enteromorpha, ectocorpus, ostrea, mytilus, slime; Although it includes organisms such as sea lettuce, green laver and marine spirogyra, the kind of biofilm that can be suppressed in the present invention is not limited by the above examples. That is, the method of suppressing the present invention is to prevent the survival and reproduction of living organisms by physical structure, rather than the method of using the microorganism-specifically reacting chemicals or another microorganism to form a biofilm, and thus, the kind of such microorganisms Without limitation, growth and proliferation can be effectively suppressed.

When the biofilm formation preventing substrate of the present invention is applied to a surface of various materials known to be contaminated or corroded by the formation of microorganisms, contamination and corrosion by microorganisms are prevented by blocking and inhibiting biofilm formation on the surface. It can be prevented or suppressed, which can lead to reduced risks and economic benefits for human infections that can be caused by contamination or corrosion.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, the following examples are provided to aid the understanding of the present invention, and the scope of the present invention is not limited to the following examples.

Example 1 Chip Fabrication

Two types of microchannel chips, 50 mu m wide and different in height, were fabricated on a stainless steel (SUS304) 6-inch wafer by photo lithography and electrochemical fabrication (ECF). According to the ECF etching time, microchannels having the same width and different heights could be produced. Channels having a height of 3 μm were prepared by 15 minutes of etching, and channels having a height of 8 μm were prepared by 30 minutes of etching. After that, the surface roughness was increased by etching with FeCl 3 solution. The manufacturing process of the chip is shown in FIG.

Example 2 Contact Angle Change Analysis

The change of contact angle of stainless steel according to the pattern height and surface roughness was measured. As shown in Figure 2, it can be seen that the contact angle is higher when the height of the pattern is 8㎛ than 3㎛. In addition, it can be seen that the contact angle is high when the etching again with FeCl ₃ solution. It is thought that the contact angle is increased due to the high surface roughness due to the FeCl ₃ etching.

Example 3. Stainless Steel Shape Observation

FE-SEM was used to compare the shape of the ECF-etched stainless steel surface and the ECF-etched FeCl ₃ etched stainless steel surface. In Figure 3 (a) is a photo of the ECF etching and FeCl ₃ etching together, (b) is a photo of ECF etching only. It can be seen that the surface of (a) is relatively rougher than the surface of (b) and nano-sized pores are formed. At this time, as a result of surface roughness measurement, the Ra value was measured as (a) at 214.6 (nm) and (b) at 154.9 (nm), respectively.

Example 4. Microbial Culture and Biofilm Formation

Pseudomonas aeruginosa (KCTC 1750) was used in this study. After culturing a solid medium (nutrient agar) and single colony (single colony) separation was carried out liquid culture (M9 medium) for 12 hours at 37 ℃. In order to form a biofilm on the chip surface, the chip was placed in a Petri dish, and then 30 ml of microbial culture solution (OD ~ 0.1) was poured and incubated at 37 ° C. for 3-4 days. Chips incubated in M9 medium without microorganism inoculation under the same conditions were used as a control.

Example 5. Fluorescence Assay

Microorganisms were stained with SYTO9 (Molecular Probes, ex: 480 nm, em: 500 nm) to confirm whether biofilms were generated through fluorescence analysis. After incubation, the chip was washed 2-3 times with M9 medium and 0.85% NaCl was added to the chip so that the chip was immersed in the conical tube. Thereafter, 3 µl of SYTO9 dye (3.34 mM) was added per 1 ml of 0.85% NaCl, and staining was performed for 15 minutes in a dark place without light. After staining, the chip was taken out, put in a new conical tube, and washed again with 2-3 times with 0.85% NaCl, followed by fluorescence microscopy (Eclipse ME600, Nikon). As can be seen in Figure 4 it can be seen that a high fluorescence signal compared to the control (-Biofilm) due to the microbial adhesion in the etched portion (dark portion on the bright field image).

1 is a schematic diagram showing a manufacturing process of a substrate for forming a groove and a porous structure on the surface.

2 is a graph showing a change in contact angle formed on a substrate.

FIG. 3 shows the SEM image (FIG. 3 (a)) by the visual method of treating both ECF and FeCl3, and the SEM image (FIG. 3 (b)) performing only ECF etching.

Figure 4 shows the results of fluorescence analysis of the biofilm formed on the surface of the substrate, a bright field image and a fluorescence image of the substrate incubated by immersing in microbial culture (+ Biofilm) and uninoculated medium (-Biofilm) Is a diagram showing.

5 is a cross-sectional view of a substrate on which grooves and porous structures are formed.

6 is a result of photographing the substrate on which the groove and the porous structure are formed by fluorescence microscope.

Claims (10)

Board; A plurality of grooves formed on the substrate; And It includes a porous structure formed in the upper front and the groove of the substrate, Substrate for preventing biofilm formation. The method of claim 1, The porous structure, A substrate for preventing biofilm formation, which is a structure having a diameter of 0.1 μm to 5 μm, an interval of 0.1 μm to 1 μm, and a depth of 1 μm to 1000 μm. The method of claim 1, The groove is, The gap of the groove is 0.1mm to 10mm, the diameter of the groove is 1㎛ 10㎛, the depth of the groove is 3㎛ 1mm substrate for preventing biofilm formation. The substrate of claim 1, wherein the substrate is made of stainless steel. (a) forming a groove in the upper portion of the substrate; And (b) forming a porous structure on the upper front side and the groove of the substrate. 6. The method of claim 5, wherein step (a) and step (b) are performed simultaneously or sequentially. The method of claim 5, wherein the step (a) is performed using chemical etching, electrochemical etching, electrical discharge, or electrolytic processing. The method of claim 5, wherein the substrate is a stainless metal. A method of preventing biofilm formation using the substrate of claim 1. The method of claim 9, wherein the microorganism is pseudomonas aeruginosa, Staphylococcus epidermidis, Delisi pulchra, methodillin resistant staphylococcus aureus, Lygo Leigonella pneumophila, Serratia, Vibrio Fischeri, Vibrio Harveyi, Klebsiella Oxytica, Enterobacter Cloacae and Candida albican (Candida albicans) A method for preventing biofilm formation, which is one or more microorganisms selected from the group consisting of.

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