Method for manufacturing wire electrode for health care biochemical sensor, and health care biochemical sensor having wire electrode manufactured using same

Abstract

A method for manufacturing a wire electrode for a health care biochemical sensor is provided. The method for manufacturing a wire electrode for a health care biochemical sensor comprises the steps of: preparing a metal wire; forming an insulating film on the surface of the metal wire by anodizing the metal wire; exposing at least one surface of the metal wire by partially etching the insulating film formed on the surface of the metal wire; and forming an electrode part on the at least one exposed surface of the metal wire, wherein, during the step of forming the insulating film on the surface of the metal wire, the formation thickness of the insulating film can be adjusted by controlling the anodizing conditions.

Description

Method for manufacturing wire electrodes for biochemical sensors for healthcare and biochemical sensors for healthcare comprising wire electrodes manufactured thereby

[0001] The present invention relates to a method for manufacturing a wire electrode for a biochemical sensor for healthcare, and to a biochemical sensor for healthcare comprising a wire electrode manufactured thereby, and more specifically, to a method for manufacturing a wire electrode for a biochemical sensor for healthcare, which enables easy and quick manufacturing of a wire electrode for a biochemical sensor for healthcare, and to a biochemical sensor for healthcare comprising a wire electrode manufactured thereby.

[0002] Surface anodization technology for aluminum, titanium, zirconium, etc. was actively used for the synthesis of nano-scale structures in the 1960s as the surface treatment technique for forming porous anodic aluminum oxide (AAO) was optimized.

[0003] In particular, anodic oxidation technology has been highlighted as a platform technology for the formation of nanowires, nanorods, and other materials. This anodic oxidation technology can form thin oxide films on metal surfaces, either with regular pores (porous type) or without pores (barrier type), and has therefore been applied to a wide range of nanostructure formation fields.

[0004] The ultra-small electrode platform used in electrochemical sensors has been mainly used in the form of a film, but recently, as the application fields have diversified to include ultra-small wearable flexible electrodes, microneedle-based electrodes, and implantable electrodes, the form is being expanded to the form of needles or wires.

[0005] However, electrode platform technology remains inadequate. Current commercially available electrochemical sensors utilize glass and porous membranes, which are fragile and bulky, making them unsuitable for wearable environments.

[0006] Furthermore, flexible electrochemical sensors are manufactured as all-solid-state / multilayer types, and adopt polymers such as polydimethylsiloxane (PDMS), polyimide (PI), and Teflon as insulators. However, these are expensive, have poor bonding properties, and have different expansion rates in liquid compared to the membrane, which is a major factor in reducing the interfacial stability of all-solid-state / multilayer types of sensors. For example, impedance signal noise may occur when exposed to tensile cracks (flexible environment), and delamination may occur between layers due to differences in expansion rates when exposed to body fluids.

[0007] In the sensor field, preventing noise is crucial, as noise can compromise the accuracy of sensing values. Therefore, insulation treatments, such as filling or the use of ceramic materials, are required to shield against noise.

[0008] However, insulating the sensor for noise shielding made it difficult to maintain its flexibility. Research using dissimilar materials has been conducted, but these have resulted in problems such as interfacial cracking, gaps, and delamination.

[0009] The technical problem to be solved by the present invention is to provide a method for manufacturing a wire electrode for a biochemical sensor for healthcare, which can easily and quickly manufacture a wire electrode for a biochemical sensor for healthcare.

[0010] Another technical problem to be solved by the present invention is to provide a biochemical sensor capable of high interface stability and noise insulation.

[0011] The technical problems to be solved by the present invention are not limited to those described above.

[0012] To solve the above technical problem, the present invention provides a method for manufacturing a wire electrode for a biochemical sensor for healthcare.

[0013] According to one embodiment, a method for manufacturing a wire electrode for a biochemical sensor for healthcare comprises the steps of: preparing a metal wire; forming an insulating film on a surface of the metal wire through anodizing the metal wire; partially etching the insulating film formed on the surface of the metal wire to expose at least one surface of the metal wire; and forming an electrode portion on at least one surface of the exposed metal wire, wherein in the step of forming the insulating film on the surface of the metal wire, a thickness of the insulating film can be adjusted by controlling the anodizing conditions.

[0014] According to one embodiment, in the step of forming an insulating film on the surface of the metal wire, an anodic oxidation solution based on any one of phosphoric acid, oxalic acid, and sulfuric acid may be used.

[0015] According to one embodiment, in the step of forming an insulating film on the surface of the metal wire, when an anodizing solution based on oxalic acid is used, the metal wire may be immersed in the anodizing solution based on oxalic acid for at least 10 minutes during anodizing.

[0016] According to one embodiment, as the immersion time of the metal wire in the anodic oxidation solution increases, the thickness of the insulating film formed on the surface of the metal wire may increase.

[0017] According to one embodiment, in the step of exposing at least one surface of the metal wire, a phosphoric acid solution may be used as the etching solution.

[0018] According to one embodiment, in the step of exposing at least one surface of the metal wire, the temperature of the phosphoric acid solution may be controlled to 98°C, and the metal wire having an insulating film formed on the surface may be immersed in the phosphoric acid solution for more than 3 minutes and less than 20 minutes.

[0019] According to one embodiment, in the step of forming the electrode portion, metal particles may be plated on at least one surface of the exposed metal wire through cyclic voltammetry-based electroplating.

[0020] According to one embodiment, in the step of forming the electrode portion, a current may be applied in steps from 0 mA to 1 mA to the solution in which the metal wire having at least one surface exposed is immersed, and 0.1 mA may be added at each step.

[0021] Meanwhile, the present invention provides a biochemical sensor for healthcare.

[0022] According to one embodiment, the biochemical sensor for healthcare comprises: a metal wire; an insulating film provided on a surface of the metal wire, exposing at least one surface of the metal wire; and an electrode part provided on at least one surface of the exposed metal wire, wherein the insulating film may be formed of an oxide film formed through anodic oxidation of the metal wire.

[0023] According to one embodiment, the device further includes a sensor unit, wherein the sensor unit is provided on the electrode unit and may be made of a material that is sensitive to a target biological material.

[0024] According to an embodiment of the present invention, there is provided a method for manufacturing a metal wire, comprising: preparing a metal wire; forming an insulating film on a surface of the metal wire through anodizing the metal wire; partially etching the insulating film formed on the surface of the metal wire to expose at least one surface of the metal wire; and forming an electrode portion on at least one surface of the exposed metal wire, wherein in the step of forming the insulating film on the surface of the metal wire, the thickness of the insulating film can be adjusted by controlling the anodizing conditions.

[0025] Accordingly, a method for manufacturing a wire electrode for a biochemical sensor for healthcare can be provided, which can easily and quickly manufacture a wire electrode for a biochemical sensor for healthcare.

[0026] In addition, according to an embodiment of the present invention, a wire electrode for a biochemical sensor for healthcare can be manufactured at room temperature and pressure.

[0027] That is, according to an embodiment of the present invention, a wire electrode for a biochemical sensor for healthcare can be easily and quickly manufactured through a simple solution-based process in a short period of time at room temperature and pressure, which can be advantageous from the perspective of mass production.

[0028] Through this, according to an embodiment of the present invention, a wire-shaped ultra-small biochemical sensor capable of high interface stability and noise insulation can be provided.

[0029] At this time, according to an embodiment of the present invention, the wire electrode can be applied not only to a biochemical sensor for healthcare, but also to a water quality sensor or a food sensor.

[0030] That is, the wire electrode manufactured according to an embodiment of the present invention can be utilized as a platform for various sensors.

[0031] FIG. 1 is a flowchart illustrating a method for manufacturing a wire electrode for a biochemical sensor for healthcare according to one embodiment of the present invention.

[0032] Figure 2 is a schematic diagram for explaining step S110 of Figure 1.

[0033] Figure 3 is a schematic diagram for explaining step S120 of Figure 1.

[0034] Figure 4 is a schematic diagram for explaining step S130 of Figure 1.

[0035] Figure 5 is a schematic diagram for explaining step S140 of Figure 1.

[0036] FIG. 6 is a schematic diagram illustrating a biochemical sensor having a wire electrode for a biochemical sensor for healthcare manufactured through a method for manufacturing a wire electrode for a biochemical sensor for healthcare according to an embodiment of the present invention.

[0037] Figure 7 is a photograph of the surface of an aluminum wire before anodic oxidation, taken using a scanning electron microscope.

[0038] Figure 8 is a photograph of the surface of an aluminum wire after anodic oxidation, taken using a scanning electron microscope.

[0039] Figure 9 shows a photograph and EDS analysis result of a cross-section of an aluminum wire after anodic oxidation.

[0040] Figure 10 is a graph showing the change in resistance over time of anodic oxidation.

[0041] Figures 11 and 12 are photographs taken with a scanning electron microscope showing changes in the surface of an aluminum wire according to an etching solution.

[0042] Figures 13 to 16 are photographs taken with a scanning electron microscope showing changes in the surface of an aluminum wire over etching time.

[0043] Figures 17 to 22 are photographs taken with a scanning electron microscope to show changes in the surface of an aluminum wire according to electroplating conditions.

[0044] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the technical concept of the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to sufficiently convey the spirit of the present invention to those skilled in the art.

[0045] In this specification, when a component is referred to as being on another component, it means that it can be formed directly on the other component, or a third component may be interposed between them. In addition, in the drawings, shapes and sizes are exaggerated for the purpose of effectively explaining the technical contents.

[0046] Additionally, although terms such as first, second, and third have been used to describe various components in various embodiments of this specification, these components should not be limited by these terms. These terms are only used to distinguish one component from another. Thus, what is referred to as a first component in one embodiment may be referred to as a second component in another embodiment. Each embodiment described and illustrated herein also includes its complementary embodiments. Additionally, the term "and / or" has been used herein to mean including at least one of the components listed before and after.

[0047] In the specification, singular expressions include plural expressions unless the context clearly dictates otherwise. In addition, terms such as "comprise" or "have" are intended to specify the presence of a feature, number, step, component, or combination thereof described in the specification, and should not be construed as excluding the presence or addition of one or more other features, numbers, steps, components, or combinations thereof. In addition, the term "connection" is used in the present specification to mean both indirectly connecting multiple components and directly connecting them.

[0048] Additionally, terms such as “part,” “unit,” and “module” described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware, software, or a combination of hardware and software.

[0049] In addition, when describing the present invention below, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

[0050]

[0051] FIG. 1 is a flowchart illustrating a method for manufacturing a wire electrode for a biochemical sensor for healthcare according to an embodiment of the present invention, FIG. 2 is a schematic diagram for explaining step S110 of FIG. 1, FIG. 3 is a schematic diagram for explaining step S120 of FIG. 1, FIG. 4 is a schematic diagram for explaining step S130 of FIG. 1, FIG. 5 is a schematic diagram for explaining step S140 of FIG. 1, and FIG. 6 is a schematic diagram for explaining a biochemical sensor including a wire electrode for a biochemical sensor for healthcare manufactured through a method for manufacturing a wire electrode for a biochemical sensor for healthcare according to an embodiment of the present invention.

[0052]

[0053] As illustrated in FIG. 1, a method for manufacturing a wire electrode for a biochemical sensor for healthcare according to an embodiment of the present invention may include steps S110, S120, S130, and S140.

[0054]

[0055] S110 stage

[0056] As shown in Fig. 2, the step S110 is a step of preparing a metal wire (110).

[0057] In the above step S110, an aluminum wire can be prepared using a metal wire (110). At this time, in the above step S110, a high-purity aluminum wire can be prepared using the metal wire (110).

[0058] For example, in the above step S110, an aluminum wire with a purity of 99.999% can be prepared using the metal wire (110).

[0059] In addition, in the above step S110, in order to manufacture an ultra-small wire electrode (100 in FIG. 5), for example, an aluminum wire having a diameter of 0.25 mm can be prepared as a metal wire (110).

[0060] That is, in the above step S110, a thin, high-purity aluminum wire can be prepared as a metal wire (110).

[0061]

[0062] S120 stage

[0063] As shown in Fig. 3, the S120 step is a step of forming an insulating film (120) on the surface of the prepared metal wire (110).

[0064] In the above step S120, an insulating film (120) can be formed on the surface of the metal wire (110) through anodizing the metal wire (110).

[0065] In this way, the insulating film (120) formed on the surface of the metal wire (110) through anodic oxidation can replace conventional polymer-based insulators. That is, the insulating film (120) formed on the surface of the metal wire (110) through anodic oxidation can ensure long-term chemical and thermal stability.

[0066] In addition, since the insulating film (120) is formed directly on the surface of the metal wire (110) through anodic oxidation, high mechanical stability can be provided.

[0067] According to one embodiment of the present invention, in step S120, an anodizing solution based on any one of phosphoric acid, oxalic acid, and sulfuric acid may be used for anodizing the metal wire (110).

[0068] In the above step S120, when the oxalic acid-based anodizing solution is used for anodizing the metal wire (110), the metal wire (110) may be immersed in the oxalic acid-based anodizing solution for at least 10 minutes during anodizing.

[0069] For example, in the above step S120, the metal wire (110) can be immersed in an oxalic acid solution and connected as an anode to an external voltage device, and the platinum substrate can also be immersed in an oxalic acid solution and connected as a cathode. Then, a chiller can be connected to maintain the temperature at 15 degrees and apply a voltage of 40 V, and anodization can be performed for 10 minutes.

[0070] In this way, when the metal wire (110) is immersed in an oxalic acid-based anodizing solution for at least 10 minutes during anodizing, an insulating film (120) of a predetermined thickness can be formed on the surface of the metal wire (110).

[0071] For example, when a metal wire (110) is immersed in an oxalic acid-based anodizing solution for at least 10 minutes during anodizing, an insulating film (120) having a thickness of approximately 10 μm can be formed on the surface of the metal wire (110).

[0072] Here, during anodic oxidation, the longer the immersion time of the metal wire (110) in the anodic oxidation solution, the more the thickness of the insulating film (120) formed on the surface of the metal wire (110) may increase.

[0073] In this way, according to one embodiment of the present invention, in the step S120, the thickness of the insulating film (120) formed on the surface of the metal wire (110) can be adjusted by controlling the anodic oxidation conditions.

[0074] That is, in the above step S120, the immersion time of the metal wire (110) in the anodic oxidation solution can be controlled, and through this, the thickness of the insulating film (120) formed on the surface of the metal wire (110) can be controlled.

[0075] Accordingly, when the manufactured wire electrode (100 in FIG. 5) is applied to a sensor requiring long-term stability, an insulating film (120) of a desired thickness can be formed by extending the anodizing process time.

[0076] Conversely, if the wire electrode being manufactured (100 in FIG. 5) is used for a one-time use, for example, a thin insulating film (120) can be formed by shortening the anodizing process time.

[0077] In particular, by controlling the anodic oxidation process time to form a thin insulating film (120) of several tens of nanometers thick on the surface of a metal wire (110), it can have flexible properties, so that the manufactured wire electrode (100 in FIG. 5) can be applied to a wearable electrochemical sensor.

[0078] In this way, when a wire electrode (100 in FIG. 5) having an insulating film (120) formed as a thin nano-sized film is applied to a wearable electrochemical sensor, it can increase cost-effectiveness, durability, accuracy, and diversity.

[0079] Meanwhile, when an anodic oxidation solution based on phosphoric acid is used during anodic oxidation, a thin film insulating film (120) can be formed on the surface of the metal wire (110).

[0080] In this way, when a thin film-type insulating film (120) is formed on the surface of a metal wire (110), it is possible to manufacture a sensor in the form of a biopsy, for example.

[0081] In addition, when an anodizing solution based on oxalic acid or an anodizing solution based on sulfuric acid is used during anodizing, an insulating film (120) composed of a porous oxide film can be formed on the surface of the metal wire (110). In this case, it may also be possible to form a sensor unit (200 in FIG. 6) within each pore.

[0082]

[0083] Step S130

[0084] As illustrated in FIG. 4, the S130 step is a step of partially etching the insulating film (120) formed on the surface of the metal wire (110) through anodic oxidation to expose at least one surface of the metal wire (110).

[0085] According to one embodiment of the present invention, in step S130, a phosphoric acid solution may be used as an etching solution for partially etching an insulating film (120) formed on the surface of a metal wire (110).

[0086] At this time, in the above step S130, the temperature of the phosphoric acid solution used can be controlled to 98°C.

[0087] In the above step S130, a metal wire (110) having an insulating film (120) formed on the surface can be immersed in a phosphoric acid solution at 98°C.

[0088] Specifically, in the above step S130, the metal wire (110) can be immersed in a phosphoric acid solution at 98°C so that one side of the insulating film (120) to be removed through etching is submerged.

[0089] Accordingly, one side of the insulating film (120) immersed in a 98°C phosphoric acid solution is etched, and through this, the surface of the metal wire (110) can be exposed to the etched portion of the insulating film (120).

[0090] According to one embodiment of the present invention, in the step S130, the metal wire (110) on which the insulating film (120) is formed can be immersed in a phosphoric acid solution at 98°C for more than 3 minutes and less than 20 minutes.

[0091] Here, when the metal wire (110) on which the insulating film (120) is formed is immersed in a phosphoric acid solution at 98°C for 3 minutes or less, most of the insulating film (120) in the immersed portion is removed, but some of the insulating film (120) that is not etched may remain.

[0092] In addition, when the metal wire (110) on which the insulating film (120) is formed is immersed in a phosphoric acid solution at 98°C for more than 20 minutes, the insulating film (120) of the immersed portion is completely removed, but some of the metal wire (110) is etched, so that the thickness of the metal wire (110) may be reduced to some extent.

[0093] Therefore, in order to completely expose at least one surface of the metal wire (110) without damaging the metal wire (110), it may be desirable to immerse the metal wire (110) on which the insulating film (120) is formed in a phosphoric acid solution at 98°C for more than 3 minutes and less than 20 minutes.

[0094]

[0095] Step S140

[0096] As illustrated in FIG. 5, the S140 step is a step of forming an electrode portion (130) on at least one surface of the exposed metal wire (110) through partial etching of the insulating film (120) formed on the surface of the metal wire (110).

[0097] In the above step S140, an electrode portion (130) can be formed by depositing metal on at least one surface of the exposed metal wire (110).

[0098] According to one embodiment of the present invention, in step S140, metal particles can be plated on at least one surface of the metal wire (110) exposed by etching through cyclic voltammetry-based electroplating.

[0099] For example, in the above step S140, gold (Au) particles can be plated on at least one surface of the metal wire (110) exposed by etching through cyclic voltammetry-based electroplating.

[0100] Thus, according to one embodiment of the present invention, in step S140, a gold (Au) thin film can be formed, for example, on at least one surface of the metal wire (110) exposed by etching, by cyclic voltammetry-based electroplating.

[0101] That is, according to one embodiment of the present invention, in step S140, an electrode portion (130) can be formed in one step without an additional bonding layer by electrolytic plating based on cyclic voltammetry on at least one surface of a metal wire (110) exposed by etching.

[0102] In this way, a sensor portion (200 in FIG. 6) made of a material sensitive to a target biological material, for example, can be formed on the electrode portion (130) formed on at least one surface of the metal wire (110) exposed by etching.

[0103] That is, the electrode portion (130) can be used as a platform for manufacturing various electrochemical biochemical sensors (10 in FIG. 6).

[0104] Meanwhile, according to one embodiment of the present invention, in the step S140, a solution based on potassium cyanide may be used to form an electrode part (130) made of gold (Au) during the electroplating.

[0105] According to one embodiment of the present invention, in the step S140, a current may be applied in steps from 0 mA to 1 mA to a solution, for example, a potassium cyanide-based solution, in which a metal wire (110) having at least one surface exposed by etching during the electroplating is immersed.

[0106] At this time, in the above S140 step, 0.1 mA of current can be added for each current application step that is performed sequentially.

[0107] Accordingly, an electrode portion (130) can be formed without any empty space on one surface of the metal wire (110) exposed by etching.

[0108] In this way, according to one embodiment of the present invention, an electrode portion (130) can be formed directly on an exposed surface of a metal wire (110) without the aid of an intermediate metal layer, and through this, deposition of a sensor material forming a sensor portion (200 in FIG. 6) on the electrode portion (130) can be enabled.

[0109] When the above step S140, i.e., the step of forming an electrode portion (130) through electroplating on one surface of a metal wire (110) exposed by etching, is completed, a wire electrode (100) according to an embodiment of the present invention can be manufactured.

[0110] As illustrated in FIG. 6, a wire electrode (100) manufactured through a method for manufacturing a wire electrode for a biochemical sensor for healthcare according to an embodiment of the present invention can be applied to a biochemical sensor (10) for healthcare.

[0111] According to one embodiment of the present invention, such a biochemical sensor (10) for healthcare may include a wire electrode (100) and a sensor unit (200).

[0112]

[0113] The above wire electrode (100) may include a metal wire (110), an insulating film (120), and an electrode portion (130).

[0114] The above metal wire (110) may be provided as a high-purity aluminum wire. For example, the above metal wire (110) may be provided as an aluminum (Al) wire having a purity of 99.999%.

[0115] At this time, the diameter of the metal wire (110) may be 0.25 mm, but is not necessarily limited thereto.

[0116] The insulating film (120) may be provided on the surface of the metal wire (110). More specifically, the insulating film (120) may be coated on the surface of the metal wire (110) in a form that wraps around the metal wire (110).

[0117] At this time, according to one embodiment of the present invention, the insulating film (120) can expose at least one surface of the metal wire (110).

[0118] This insulating film (120) may be formed of an oxide film formed through anodic oxidation of a metal wire (110).

[0119] According to one embodiment of the present invention, the thickness of the insulating film (120) can be adjusted depending on the purpose. Accordingly, the insulating film (120) can be provided with an optimal thickness that can protect the metal wire (110) without reducing sensitivity.

[0120] Through this, according to one embodiment of the present invention, a biochemical sensor (10) capable of noise insulation while having high interface stability can be provided.

[0121] The electrode portion (130) may be provided on at least one surface of the exposed metal wire (110). The electrode portion (130) may be made of, for example, gold (Au). However, this is merely an example, and the material forming the electrode portion (130) is not limited to only gold (Au).

[0122] According to one embodiment of the present invention, the electrode portion (130) may be formed on at least one surface of the exposed metal wire (110) through electroplating.

[0123]

[0124] The above sensor unit (200) may be provided on the electrode unit (130). This sensor unit (200) may be made of a material that is sensitive to a target biological substance such as glucose, for example.

[0125] According to one embodiment of the present invention, various sensor materials can be formed on the electrode portion (130).

[0126] In this way, the wire electrode (100) manufactured through the method for manufacturing a wire electrode for a biochemical sensor for healthcare according to one embodiment of the present invention can be provided as a platform capable of forming sensor materials for various electrochemical biochemical sensors (10).

[0127] At this time, the above wire electrode (100) can be applied to a biochemical sensor (10) for health care as well as a water quality sensor or a food sensor.

[0128] Meanwhile, the biochemical sensor (10) for healthcare may further include a membrane (300). The membrane (300) may be provided in a form that covers a wire electrode (100) having a sensor unit (200) mounted on an exposed area in the longitudinal direction.

[0129]

[0130] Experimental Example 1

[0131] An aluminum wire with a diameter of 0.25 mm and a purity of 99.999% was immersed in a 0.3 M oxalic acid solution. The aluminum wire was then connected to an external power supply as the positive electrode and a platinum substrate as the negative electrode. A temperature controller was used to maintain the temperature at 15°C, and a voltage of 40 V was applied for anodization for 10 minutes.

[0132]

[0133] Fig. 7 is a photograph taken with a scanning electron microscope of the surface of an aluminum wire before anodization, and Fig. 8 is a photograph taken with a scanning electron microscope of the surface of an aluminum wire after anodization.

[0134] Comparing Figures 7 and 8, it can be seen that the surface of the aluminum wire has changed after anodizing. The scanning electron microscope photograph in Figure 8 was taken after the surface of the anodized aluminum wire was washed to remove impurities.

[0135] In addition, Fig. 9 is a photograph and EDS analysis result of a cross-section of an aluminum wire after anodization, and Fig. 10 is a graph showing the change in resistance according to anodization time.

[0136] First, referring to Fig. 9, when the cross-section of an aluminum wire that was anodized by immersing the aluminum wire in an oxalic acid-based solution was observed using an elemental analyzer utilizing X-ray spectroscopy, it can be confirmed that a 10㎛ thick film was formed on the aluminum wire, which appears green. Since this film contains a large amount of oxygen, which is expressed in purple, it can be confirmed that an oxide film was formed on the surface of the aluminum wire through anodization.

[0137] This demonstrates that an oxide film can be formed and grown on the surface of an aluminum wire through anodic oxidation using an oxalic acid-based solution.

[0138] Referring to Figure 10, when anodizing using an oxalic acid-based solution was performed, the resistance of the system was measured at 10-minute intervals, and a tendency for the resistance of the system to increase over time was observed. This is confirmed to be due to the growth of an oxide film on the aluminum wire in the system, acting as an insulating film, thereby increasing the resistance.

[0139]

[0140] Experimental Example 2

[0141] An aluminum wire anodized for 10 minutes in an oxalic acid-based solution was immersed in a mixed solution containing 1.8 wt% chromic acid and 6 wt% phosphoric acid at 25°C, and the oxide film formed on the surface of the anodized aluminum wire was etched.

[0142]

[0143] Experimental Example 3

[0144] An aluminum wire anodized for 10 minutes in an oxalic acid-based solution was immersed in a 98°C, 85 wt% phosphoric acid solution to etch away the oxide film formed on the surface of the anodized aluminum wire.

[0145]

[0146] Figures 11 and 12 are photographs taken with a scanning electron microscope showing changes in the surface of an aluminum wire according to an etching solution.

[0147] Comparing Figures 11 and 12, in the case of Experimental Example 2 where an anodized aluminum wire was etched in a mixed solution of chromic acid and phosphoric acid, only a portion of the oxide film on the surface of the anodized aluminum wire was removed, and a porous oxide film was observed.

[0148] On the other hand, in the case of Experimental Example 3 where an anodized aluminum wire was etched in a phosphoric acid solution, it can be confirmed that the oxide film on the surface of the anodized aluminum wire was completely removed, revealing the surface of the aluminum wire.

[0149] At this time, the oxide film is etched only to the depth immersed in the phosphoric acid solution, and it can be confirmed with an electron microscope that the unetched portion and the etched portion are clearly distinguished.

[0150]

[0151] Experimental Example 4

[0152] An aluminum wire anodized for 10 minutes in an oxalic acid-based solution was immersed in a 98°C, 85 wt% phosphoric acid solution for 20 minutes, and the oxide film formed on the surface of the anodized aluminum wire was etched.

[0153]

[0154] Experimental Example 5

[0155] An aluminum wire anodized for 10 minutes in an oxalic acid-based solution was immersed in a 98°C, 85 wt% phosphoric acid solution for 3 minutes, and the oxide film formed on the surface of the anodized aluminum wire was etched.

[0156]

[0157] Figures 13 to 16 are photographs taken with a scanning electron microscope showing changes in the surface of an aluminum wire over etching time.

[0158] Referring to FIGS. 13 and 14, in the case of Experimental Example 4 where an anodized aluminum wire was immersed in a phosphoric acid solution for 20 minutes, it can be confirmed that the oxide film on the surface of the anodized aluminum wire was completely removed, but the aluminum wire was partially etched, so that the thickness of the aluminum wire was reduced somewhat.

[0159] Also, referring to FIGS. 15 and 16, in the case of Experimental Example 5 where the anodized aluminum wire was immersed in a phosphoric acid solution for 3 minutes, it can be seen that most of the oxide film on the surface of the anodized aluminum wire was removed, but some oxide film remained in the fine cracks on the surface of the aluminum wire.

[0160] At this time, in the case of Experimental Example 5, it can be confirmed that the phosphoric acid solution does not affect the aluminum wire, and thus there is no change in the thickness of the aluminum wire.

[0161] Accordingly, it was confirmed that by using a high-concentration phosphoric acid solution as an etching solution and controlling the immersion time of an anodized aluminum wire, an oxide film several ㎛ thick can be accurately removed within several minutes only to the depth of immersion in the etching solution, and the etching solution can be controlled so that it does not affect the aluminum wire.

[0162]

[0163] Experimental Example 6

[0164] The aluminum wire, which was exposed by etching away the oxide film formed through anodic oxidation, was immersed 1.5 cm in a 55°C potassium cyanide-based solution. Then, the immersed aluminum wire was connected to an external power supply with a negative (-) terminal and a platinum substrate with a positive (+) terminal.

[0165] In this state, voltage or current was applied through an external power supply to cause gold ions to be reduced and deposited on the surface of the aluminum wire.

[0166] At this time, in the initial stage of electroplating, plating was performed by applying a voltage in the range of 0.8 V to 1 V at a scan speed of 400 mV / s for several repetitions (750 cycles).

[0167]

[0168] Experimental Example 7

[0169] The aluminum wire, which was exposed by etching away the oxide film formed through anodic oxidation, was immersed 1.5 cm in a 55°C potassium cyanide-based solution. Then, the immersed aluminum wire was connected to an external power supply with a negative (-) terminal and a platinum substrate with a positive (+) terminal.

[0170] In this state, voltage or current was applied through an external power supply to cause gold ions to be reduced and deposited on the surface of the aluminum wire.

[0171] At this time, unlike Experimental Example 6, the method of applying current was changed. When applying a voltage in the range of 0.8 V to 1 V, the maximum current of the system measured was 50 μA to 70 μA, and plating was performed by repeating the current from 0 mA to 1 mA in 0.5 mA current steps several times (300 cycles).

[0172]

[0173] Experimental Example 8

[0174] The aluminum wire, which was exposed by etching away the oxide film formed through anodic oxidation, was immersed 1.5 cm in a 55°C potassium cyanide-based solution. Then, the immersed aluminum wire was connected to an external power supply with a negative (-) terminal and a platinum substrate with a positive (+) terminal.

[0175] In this state, voltage or current was applied through an external power supply to cause gold ions to be reduced and deposited on the surface of the aluminum wire.

[0176] At this time, plating was performed by repeating the current from 0 mA to 1 mA in 0.1 mA current steps several times (300 cycles).

[0177]

[0178] Figures 17 to 22 are photographs taken with a scanning electron microscope to show changes in the surface of an aluminum wire according to electroplating conditions.

[0179] First, referring to FIGS. 17 and 18, in the case of Experimental Example 6, where plating was performed on an aluminum wire through electroplating conditions in which a voltage ranging from 0.8 V to 1 V was applied repeatedly several times at a scan speed of 400 mV / s, gold particles with a diameter of approximately 600 nm were evenly plated on the surface of the aluminum wire, but a plating film covering the entire surface of the aluminum wire failed to be secured.

[0180] Next, referring to FIGS. 19 and 20, in Experimental Example 7, where plating was performed on an aluminum wire under electroplating conditions in which a current from 0 mA to 1 mA was repeated several times in 0.5 mA current steps, gold particles with a diameter of approximately 10 μm were plated on the surface of the aluminum wire. In Experimental Example 7, a plating film was formed on most of the surface of the aluminum wire compared to Experimental Example 6, which controlled the voltage conditions, but it was confirmed that some empty spaces still existed.

[0181] Next, referring to FIGS. 21 and 22, in the case of Experimental Example 8, where plating was performed on an aluminum wire through electroplating conditions in which a current of 0 mA to 1 mA was repeated several times in 0.1 mA current steps, it can be confirmed that a uniform gold plating film was formed on the surface of the aluminum wire without any empty space.

[0182] Through this, the optimal electroplating conditions were confirmed to enable the deposition of sensor materials by directly forming gold on the surface of the aluminum wire without the aid of an intermediate metal layer.

[0183]

[0184] While the present invention has been described in detail using preferred embodiments, the scope of the present invention is not limited to the specific embodiments described above, and should be interpreted in accordance with the appended claims. Furthermore, those skilled in the art will appreciate that numerous modifications and variations are possible without departing from the scope of the present invention.

Claims

1. Step for preparing metal wire; A step of forming an insulating film on the surface of the metal wire through anodic oxidation of the metal wire; A step of partially etching an insulating film formed on the surface of the metal wire to expose at least one surface of the metal wire; and A step of forming an electrode portion on at least one surface of the exposed metal wire; A method for manufacturing a wire electrode for a biochemical sensor for healthcare, wherein in the step of forming an insulating film on the surface of the metal wire, the thickness of the insulating film is controlled by controlling the anodic oxidation conditions.

2. In paragraph 1, A method for manufacturing a wire electrode for a biochemical sensor for healthcare, wherein in the step of forming an insulating film on the surface of the metal wire, an anodic oxidation solution based on any one of phosphoric acid, oxalic acid, and sulfuric acid is used.

3. In paragraph 2, A method for manufacturing a wire electrode for a biochemical sensor for healthcare, wherein in the step of forming an insulating film on the surface of the metal wire, when an anodizing solution based on oxalic acid is used, the metal wire is immersed in the anodizing solution based on oxalic acid for at least 10 minutes during anodizing.

4. In paragraph 3, A method for manufacturing a wire electrode for a biochemical sensor for healthcare, wherein the longer the immersion time of the metal wire in the anodic oxidation solution, the thicker the insulating film formed on the surface of the metal wire becomes.

5. In paragraph 1, A method for manufacturing a wire electrode for a biochemical sensor for healthcare, wherein a phosphoric acid solution is used as an etching solution in the step of exposing at least one surface of the metal wire.

6. In paragraph 5, A method for manufacturing a wire electrode for a biochemical sensor for healthcare, wherein in the step of exposing at least one surface of the metal wire, the temperature of the phosphoric acid solution is controlled to 98°C, and the metal wire having an insulating film formed on the surface is immersed in the phosphoric acid solution for more than 3 minutes and less than 20 minutes.

7. In paragraph 1, A method for manufacturing a wire electrode for a biochemical sensor for healthcare, wherein in the step of forming the electrode portion, metal particles are plated on at least one surface of the exposed metal wire through cyclic voltammetry-based electroplating.

8. In paragraph 7, A method for manufacturing a wire electrode for a biochemical sensor for healthcare, wherein in the step of forming the electrode portion, a current is applied stepwise from 0 mA to 1 mA to a solution in which the metal wire with at least one surface exposed is immersed, adding 0.1 mA at each step.

9. Metal wire; An insulating film provided on the surface of the metal wire, exposing at least one surface of the metal wire; and An electrode portion provided on at least one surface of the exposed metal wire; A biochemical sensor for healthcare, wherein the insulating film is formed by an oxide film formed through anodic oxidation of the metal wire.

10. In paragraph 9, Including a sensor section, A biochemical sensor for healthcare, wherein the sensor section is provided on the electrode section and is made of a material that is sensitive to a target biological substance.

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