KR20230030161A - Skin moisture sensor, method for preparing the same, and skin condition monitoring device using the same - Google Patents

Abstract

Provided are a sensor for sensing a skin condition based on a moisture ratio or a water content percentage of a skin, a manufacturing method thereof, and a skin condition monitoring device using the same. A moisture sensor comprises: one or more sensing electrodes disposed on a base; and a conductive elastic layer disposed at least partially and directly on the sensing electrodes.

Description

Skin moisture sensor, manufacturing method thereof, and skin condition monitoring device using the same

The present invention relates to a moisture sensor, a manufacturing method thereof, and a skin condition monitoring device using the same. In detail, it relates to a sensor for sensing a skin condition based on moisture content or water content of the skin, a manufacturing method thereof, and a skin condition monitoring device using the same.

Various attempts have been made to measure the moisture content of the skin. Human skin is an indispensable organ for sustaining life in that it not only forms a film that separates the inside and outside of the body, but also functions as body protection, tactile sensation, and temperature control.

In addition, human skin, for example, the skin of the face or hands, is one of the parts where aging is most quickly recognized because it is exposed to sunlight for a long time. Collagen in the skin decreases and elastin increases due to ultraviolet rays, and as the skin moisture content decreases, the skin becomes thinner and elasticity decreases, resulting in wrinkles.

Maintaining the amount of moisture in the skin at an appropriate level activates the physiological activity and metabolism of the skin, and is also important in terms of beauty. In order to supply sufficient moisture and nutrients to the skin, moisturizers, moisture creams, mask packs, and various cosmetics are used. However, since people's skin is different, such as dry or oily, it is required to objectively identify the skin condition.

In addition to the cosmetic aspects as described above, measuring the amount of moisture in a person's skin can be used for various purposes. Accordingly, various studies have been conducted to measure moisture in the surface, epidermis, or dermis of human skin. Methods for measuring skin moisture can be largely classified into a Trans Epidermal Water Loss (TEWL) method and an electrical conductivity method for measuring the evaporation rate of moisture from the skin surface.

Among them, the electrical conductivity method is a method of estimating the moisture content of the skin surface by measuring the impedance from the amount of current flowing along the human skin surface. For example, when the impedance is high, the moisture content may be low, and when the impedance is low, the moisture content may be high.

Republic of Korea Patent Registration No. 10-2244686, skin condition measuring device Republic of Korea Patent Registration No. 10-1213157, skin impedance measurement sensor Republic of Korea Patent Publication No. 10-2014-0121059, sensor module and sensor module system Republic of Korea Patent Publication No. 10-2014-0124190, moisture detection sensor and system and method

A moisture sensor using a conventional electrical conductivity method is mainly provided in the form of a device as disclosed in Patent Document 1. That is, it is based on measuring the amount of moisture at a point on the skin using a hard electrode. However, since human skin is flexible and has a curved surface, and the curve of the skin changes when a person moves, this type of moisture sensor can measure skin moisture, but it is difficult to monitor the skin moisture condition in real time. .

In addition, as in Patent Document 3 and Patent Document 4, various studies have been conducted to measure the amount of moisture on the surface or inside of human skin. However, despite the movement of a person, it is difficult to attach electrodes for measuring electrical conductivity to the skin, so the above type of electrical conductivity type moisture sensor has not been commercialized.

Therefore, the problem to be solved by the present invention is to provide a flexible moisture sensor that can be easily adhered along the curves of human skin. In addition, a sensing electrode for measuring electrical conductivity is in close contact with human skin to provide a moisture sensor with improved reliability.

Another problem to be solved by the present invention is to provide a method for manufacturing a flexible moisture sensor that can be easily adhered along the curves of human skin.

Another problem to be solved by the present invention is to provide a skin condition monitoring device using a moisture sensor having improved reliability.

The tasks of the present invention are not limited to the technical tasks mentioned above, and other technical tasks not mentioned will be clearly understood by those skilled in the art from the following description.

A moisture sensor according to an embodiment of the present invention for solving the above problems includes one or more sensing electrodes disposed on a base; and a conductive elastic layer disposed at least partially directly on the sensing electrode.

In some embodiments, the moisture sensor may include a polymer coating layer disposed between the base and the sensing electrode; and an insulating layer disposed at least partially in contact with a side surface of the sensing electrode.

The polymer coating layer contains 80% or more of a polyurethane-based polymer, and the base may be a fiber base having flexibility and air permeability.

In addition, the sensing electrode may include silver (Ag), and the conductive elastic layer may be a conductive silicon layer containing silicon.

The conductive elastic layer may include silicon and metallic particles having an average particle size in the range of 5 μm to 50 μm dispersed in the silicon.

In some embodiments, the moisture sensor may further include an insulating layer at least partially disposed on the sensing electrode, and the insulating layer may come into contact with the conductive elastic layer.

Also, the insulating layer may be at least partially interposed between the sensing electrode and the conductive elastic layer.

Also, the conductive elastic layer may at least partially come into contact with an upper surface of the insulating layer and a side surface of the sensing electrode.

In some embodiments, the moisture sensor may further include a rear electrode passing through the base and conducting with the sensing electrode, and the rear electrode may overlap the conductive elastic layer.

The modulus of the conductive elastic layer may be in the range of 0.1 MPa to 1.5 MPa.

A method of manufacturing a moisture sensor according to an embodiment of the present invention for solving the above other problems includes disposing one or more sensing electrodes on a base and disposing a conductive elastic layer at least partially on the sensing electrodes.

The method may further include disposing an insulating layer at least partially on the sensing electrode before disposing the conductive elastic layer.

Also, the method may further include exposing an upper surface of the sensing electrode by partially removing the insulating layer before disposing the conductive elastic layer.

A skin monitoring device according to an embodiment of the present invention for solving the above another problem includes the above-described moisture sensor.

The skin monitoring device may include one or more of a mask pack, a wound covering material, and a diaper.

Other embodiment specifics are included in the detailed description.

According to embodiments of the present invention, adhesion of a conduction path for measuring electrical conductivity to the skin may be increased by including a conductive elastic layer disposed on the sensing electrode. Therefore, even when a person moves, for example, when a mask pack to which the moisture sensor according to the present invention is applied is attached and smiles, the reliability of measuring the moisture content can be increased.

In addition, the moisture sensor according to the present invention can improve durability by providing a polymer coating layer having excellent adhesion to the sensing electrode on the fiber base. For example, even when the moisture sensor is repeatedly bent, the reliability of the moisture sensor as in the initial state can be maintained.

Effects according to the embodiments of the present invention are not limited by the contents exemplified above, and more diverse effects are included in the present specification.

1 is a perspective view modeling a moisture sensor according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line AA′ of FIG. 1 .
FIG. 3 is a cross-sectional view taken along line BB′ of FIG. 1 .
4 is a cross-sectional view of a moisture sensor according to another embodiment of the present invention.
5 is a cross-sectional view of a moisture sensor according to another embodiment of the present invention.
6 to 8 are cross-sectional views of moisture sensors according to still other embodiments of the present invention, respectively.
9 to 12 are cross-sectional views illustrating a method of manufacturing a moisture sensor according to an embodiment of the present invention.
13 to 16 are cross-sectional views illustrating a method of manufacturing a moisture sensor according to another embodiment of the present invention.
17 to 21 are cross-sectional views illustrating a method of manufacturing a moisture sensor according to another embodiment of the present invention.
22 is an image showing a moisture sensor according to a manufacturing example.
23 and 24 are images showing the results according to Experimental Example 1 and Experimental Example 2, respectively.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only the embodiments make the disclosure of the present invention complete, and those skilled in the art in the art to which the present invention belongs It is provided to fully inform the person of the scope of the invention, and the invention is only defined by the scope of the claims. That is, various changes may be made to the embodiments provided by the present invention. The embodiments described below are not intended to be limiting on the embodiments, and should be understood to include all modifications, equivalents or substitutes thereto.

The size, thickness, width, length, etc. of the components shown in the drawings may be exaggerated or reduced for convenience and clarity of explanation, so the present invention is not limited to the illustrated form.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used in a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless explicitly specifically defined.

The spatially relative terms 'above', 'upper', 'on', 'below', 'beneath', 'lower', etc. are not included in the drawings. As shown, it can be used to easily describe the correlation between one element or component and another element or component. Spatially relative terms should be understood as encompassing different orientations of elements in use in addition to the orientations shown in the figures. For example, when elements shown in the figures are turned over, elements described as 'below' or 'below' other elements may be placed 'above' the other elements. Accordingly, the exemplary term 'below' may include directions of both down and up.

In this specification, 'and/or' includes each and every combination of one or more of the recited items. In addition, singular forms also include plural forms unless otherwise specified in the text. As used herein, 'comprises' and/or 'comprising' does not exclude the presence or addition of one or more other elements other than the recited elements. A numerical range expressed using 'to' indicates a numerical range including the values listed before and after it as the lower limit and the upper limit, respectively. 'About' or 'approximately' means a value or range of values within 20% of the value or range of values set forth thereafter.

In addition, the first direction (X) means any one direction in the plane, and the second direction (Y) means another direction that crosses or is perpendicular to the first direction (X) in the plane. The third direction (Z) means another direction that crosses or is perpendicular to the plane.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view modeling a moisture sensor according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line A-A' in FIG. 1 . FIG. 3 is a cross-sectional view taken along line BB′ of FIG. 1 .

1 to 3, the moisture sensor 1 according to the present embodiment is a base substrate 100, a sensing electrode 200 disposed on the base substrate 100, and a sensing electrode 200 disposed on the A conductive elastic layer 400 may be included, and an insulating layer 300 may be further included.

The base substrate 100 may provide a space in which a sensing electrode 200 to be described later is disposed. Hereinafter, an example in which the base substrate 100 provides a plane space in which the first direction (X) and the second direction (Y) belong will be described. The base substrate 100 may include a fiber base 110 and a polymer coating layer 130 .

Base 110 may include fibers. For example, the base 110 may be polypropylene (PP), polyethylene (PE), polyethyleneterephthalate (PET), polyether sulfone (PES), polyester or nylon. It may be prepared using a polymeric synthetic fiber such as (nylon).

As a non-limiting example, the base 110 may include a non-woven fabric using the polymer synthetic fiber, or a woven fabric or a knitted fabric. When the base 110 is made of nonwoven fabric, it may be manufactured through a process such as melt blown, spunbond, spunlace, or needle punching.

The base 110 prepared using the polymer synthetic fiber may have excellent flexibility and air permeability. For example, the base 110 may maintain its shape and may not change its physical structure even when repeated bending or folding occurs more than about 100 times, more than about 500 times, or more than about 1,000 times. .

In addition, when tested according to KS K 0570:2006, the base 110 is about 50 cm ³ /cm ² -min or more, or about 100 cm ³ /cm ² -min or more, about 200 cm ³ /cm ² -min or more, about 300 cm ³ /cm ² -min or more may have permeability. As will be described later, the moisture sensor 1 according to the present embodiment may be used as a skin mask pack or a wound dressing film. Therefore, diversification of utilization can be achieved by making the base 110 supporting the sensing electrode 200 and the like have high air permeability.

A polymer coating layer 130 may be disposed on the base 110 . The polymer coating layer 130 may be directly disposed on the fiber base 110 . The coating layer 130 may have electrical insulating properties. The polymer coating layer 130 may be disposed on at least a portion of the base 110 but not on the entire surface, but the present invention is not limited thereto.

The coating layer 130 may function to improve durability of the sensing electrode 200 to be described later. Unlike the present embodiment, if the sensing electrode 200 is directly disposed on the base 110 without the coating layer 130, the sensing electrode 200 is lifted from the base 110 in a process such as repetitive bending, Problems such as cracks in the sensing electrode 200 may occur. This may be because the upper surface of the fiber base 110 has irregularities. The coating layer 130 may improve physical and chemical bonding strength between the base 110 and the sensing electrode 200 and planarize the surface of the base 110 having a high surface roughness.

In an exemplary embodiment, the coating layer 130 may include a urethane-based polymer, a silicone-based polymer, and/or a combination thereof. For example, the coating layer 130 may contain about 80% or more, or about 90% or more of urethane-based polymer or polyurethane polymer and/or silicone. The urethane-based polymer or the silicone-based polymer may have excellent adhesion to the base 110 made of synthetic resin fibers or the like and may be applied uniformly. In addition, a urethane-based polymer may be particularly preferable in terms of bonding strength with the sensing electrode 200 .

A thickness of the coating layer 130 may be smaller than a thickness of the base 110 . For example, the thickness of the coating layer 130 ranges from about 0.01 μm to 100 μm, or from about 0.01 μm to 50 μm, or from about 0.1 μm to 30 μm, or from about 1.0 μm to 10 μm, or from about 3.0 μm to 5.0 μm. can be in

If the thickness of the coating layer 130 is too thick, the overall air permeability of the base substrate 100 may decrease. In addition, if the thickness of the coating layer 130 is too thick, cracks may occur in the coating layer 130 itself during repetitive bending. On the other hand, when the thickness of the coating layer 130 is smaller than the above range, the flattening effect of the surface of the base 110 is not sufficient, and sufficient bonding between the base 110 and the sensing electrode 200 may not be achieved.

A sensing electrode 200 may be disposed on the base substrate 100 . For example, the sensing electrode 200 may be directly disposed on the coating layer 130 . The sensing electrode 200 may include a first sensing electrode 210 and a second sensing electrode 220 and may be formed as a pair. The first sensing electrode 210 and the second sensing electrode 220 may extend substantially in the first direction X and may be spaced apart from each other in the second direction Y, but the present invention is not limited thereto.

The first sensing electrode 210 and the second sensing electrode 220 may not directly conduct because they do not come into contact with each other. The first sensing electrode 210 and the second sensing electrode 220 may be electrically connected to a processor or the like. The first sensing electrode 210 and the second sensing electrode 220 may measure impedance from the amount of current flowing along them and sense the amount of moisture in the skin. To this end, the processor may refer to means for generating voltage/current, measuring voltage/current, calculating impedance, or recording or processing them. For example, the processor may include a central processing unit (CPU), a micro processor unit (MPU), a micro controller unit (MCU), or any type of processor known in the art.

Although the present invention is not limited thereto, in some embodiments, the processor may store an impedance value according to the moisture content of the contact surface. Based on this, the amount of moisture in the user's skin may be calculated based on the current value and the calculated impedance flowing along the user's skin.

The sensing electrode 200 may have relatively excellent electrical conductivity. In an exemplary embodiment, the sensing electrode 200 may include a metal such as silver (Ag), gold (Au), or copper (Cu) or the metal paste. The sensing electrode 200 may at least partially come into contact with human skin, and in this respect, it may be particularly desirable that the sensing electrode 200 include silver or gold.

An insulating layer 300 may be disposed on the sensing electrode 200 . The insulating layer 300 may have substantially electrical insulating properties. The insulating layer 300 may be directly disposed on the sensing electrode 200 . For example, the insulating layer 300 may at least partially contact the top and side surfaces of the sensing electrode 200 . Also, the insulating layer 300 may come into contact with the coating layer 130 .

In an exemplary embodiment, the insulating layer 300 may be disposed only on a portion of the sensing electrode 200 and may not be disposed on another portion of the sensing electrode 200 . Specifically, the insulating layer 300 is a portion of the sensing electrode 200 other than a portion of the sensing electrode 200 in contact with human skin and/or a portion of the sensing electrode 200 to be electrically connected to the processor. It can be arranged to cover. That is, by limiting a part of the sensing electrode 200 that is in contact with or conducting human skin to a specific part, the reliability of sensing the amount of moisture is improved, and at the same time, as the area in contact between the sensing electrode 200 and the skin becomes excessively large, It is possible to suppress noise signals etc.

In addition, the insulating layer 300 may at least partially contact the coating layer 130 . The material of the insulating layer 300 is not particularly limited as long as it has electrical insulating properties, but may include a polyurethane-based or urethane-based polymer material in terms of adhesion to the coating layer 130 and durability of the moisture sensor 1 through it. .

A conductive elastic layer 400 (or a conductive adhesive layer) may be disposed on the sensing electrode 200 . The conductive elastic layer 400 may be disposed on a portion of the sensing electrode 200 on which the insulating layer 300 is not disposed. When there are a plurality of sensing electrodes 200 including the first sensing electrode 210 and the second sensing electrode 220 as in the present embodiment, the conductive elastic layer 400 may be disposed for each sensing electrode. The conductive elastic layer 400 may overlap or non-overlap the insulating layer 300 in the third direction (Z). In some embodiments, the conductive elastic layer 400 may at least partially contact the insulating layer 300 .

As described above, the moisture sensor 1, in particular, is not a moisture sensor in the form of a device using contact for a predetermined time, but is a non-limiting example of a person for a relatively long period of time, such as a mask pack for cosmetic purposes, a wound covering material, etc. In the case of a moisture sensor attached to the skin to monitor the skin moisture content, the sensing electrode 200 is in close contact with the skin despite the curves and wrinkles of human skin, specifically, the conduction path between the skin and the sensing electrode 200 can be a very important factor.

In detail, even when a person wears a skin condition monitoring device to which the moisture sensor 1 according to the present embodiment is applied and curves occur in the skin in the course of daily life, in order to measure impedance with high reliability, the sensing electrode It is necessary for the 200 to maintain an electrically conductive state by directly or indirectly contacting a person's skin.

The moisture sensor 1 according to the present embodiment includes the conductive elastic layer 400 disposed on the sensing electrode 200 and can improve adhesion to the skin by using the elasticity of the conductive elastic layer 400 . That is, even if the sensing electrode 200, which has less flexibility or elasticity than the conductive elastic layer 400, does not directly contact human skin, the conductive elastic layer 400 can be closely adhered to along the curves of human skin, and the conductive elastic layer 400 can adhere to the human skin. Since the layer 400 and the sensing electrode 200 are electrically conductive, the conductive elastic layer 400 may be used as an electrode for measuring impedance. In other words, the conductive elastic layer 400 is used as a conduction path between the skin and the sensing electrode 200, and at the same time adheres to the skin so that current can be measured without interruption.

In addition, even when the sensing electrode 200 is formed of a metal paste or the like instead of a plate, the sensing electrode 200 may give a user a foreign body sensation. Accordingly, the conductive elastic layer 400 having high elasticity and flexibility may be configured to come into direct contact with human skin, thereby improving user convenience.

To this end, the thickness of the conductive elastic layer 400 may be greater than that of the insulating layer 300 . For example, the minimum thickness of the conductive elastic layer 400 may be in a range of about 50 μm to 2,000 μm, or about 60 μm to 1,500 μm, or about 70 μm to 1,000 μm.

In addition, the conductive elastic layer 400 not only improves adhesion to the skin, but also suppresses damage to the sensing electrode 200 and maintains reliability even when the user's skin and the portion where the sensing electrode 200 is conductive are repeatedly bent. can make it This will be described later along with experimental examples.

On the other hand, when only the conductive elastic layer 400 is used without using the sensing electrode 200 using metal or metal paste, the conductive elastic layer 400 has lower electrical conductivity and higher impedance than the sensing electrode 200. Because of this, the reliable measurement range of moisture content can be reduced. On the other hand, as in the present embodiment, by disposing the conductive elastic layer 400 only partially on the sensing electrode 200 made of metal paste, it is possible to achieve both adhesion to the skin and securing electrical conductivity. In some embodiments, the thickness of the conductive elastic layer 400 may be about 80% or less, or about 70% or less, or about 60% or less, or about 50% or less of the thickness of the sensing electrode 200 .

In an exemplary embodiment, the conductive elastic layer 400 may include a polymer and metallic particles dispersed in a polymer material.

For example, the conductive elastic layer 400 may include a silicon-based polymer. The silicone polymer may have excellent dispersing ability for metallic particles and excellent binding force with metal paste. In addition, it may be preferable in terms of stability even if it is in close contact with human skin for a long time. In this case, the modulus (or elasticity) of the conductive elastic layer 400 may be in the range of about 0.1 MPa to 1.5 MPa, or about 0.3 MPa to 1.0 MPa, or about 0.5 MPa to 0.7 MPa. In addition, the viscosity of the conductive elastic layer 400, for example, shear viscosity, is about 3.0 kPa s to 10.0 kPa s, or about 4.0 kPa s to 8.0 kPa s, or about 5.0 kPa s to 6.0 It may be in the kPa·s range.

If the elasticity and viscosity of the conductive elastic layer 400 are less than the above ranges, a foreign body sensation may be provided to the user, or adhesion to the skin may not be sufficient. On the other hand, when the elasticity and viscosity of the conductive elastic layer 400 are greater than the above ranges, the durability of the conductive elastic layer 400 is reduced and the conductive elastic layer 400 is damaged due to repeated use, or a minute amount is applied to the user's skin. Silicone and the like may remain.

The type of the metallic particles is not particularly limited, but when the sensing electrode 200 includes silver (Ag) or gold (Au), the conductive elastic layer 400 may include metallic particles as well as silver or gold particles. there is. The size of the metallic particles may have an average particle size in the range of about 5 μm to 50 μm. When the size of the metallic particles is larger than the above range, at least a part of the metallic particles protrudes outside the conductive elastic layer 400 and may damage the user's skin or give a foreign body sensation. On the other hand, if the size of the metallic particle is smaller than the above range, it may not have sufficient electrical conductivity.

The metallic particles may be included in an amount of about 5.0 wt% to about 20.0% based on the total weight of the conductive elastic layer 400 . If the content is less than the above range, it may not have sufficient electrical conductivity. On the other hand, if the content is greater than the above range, it may give the user a foreign body feeling.

As described above, the moisture sensor 1 according to the present embodiment can increase adhesion to human skin, minimize foreign body sensation to the user, and measure moisture content with high reliability.

In addition, the moisture sensor according to the present invention can be used in various skin condition monitoring devices such as mask packs, creative covering materials, such as bandages, beauty, medical, and health care products, diapers, or lie detectors, skin condition monitors, and oil and water fraction meters. can

Hereinafter, other embodiments of the present invention will be described. However, a description of the same or extremely similar configuration as the above-described embodiment will be omitted, which will be understood by those skilled in the art from the accompanying drawings.

Figure 4 is a cross-sectional view of a moisture sensor according to another embodiment of the present invention, a cross-sectional view showing a position corresponding to Figure 2.

Referring to FIG. 4, the moisture sensor 2 according to the present embodiment includes a sensing electrode 200 disposed on a base substrate 100, an insulating layer 300 disposed on the sensing electrode 200, and a conductive elastic layer. 402 is included, but the conductive elastic layer 402 overlaps the insulating layer 300 in the third direction Z, which is different from the embodiment of FIG. 2 .

The insulating layer 300 may be at least partially interposed between the sensing electrode 200 and the conductive elastic layer 402 . Also, according to this, the conductive elastic layer 402 may come into contact with the top surface as well as the side surface of the insulating layer 300 .

As in the present embodiment, the conductive elastic layer 402 is provided to have a sufficient planar area, so that the moisture content can be measured more smoothly.

Figure 5 is a cross-sectional view of a moisture sensor according to another embodiment of the present invention, showing a position corresponding to Figure 2.

Referring to FIG. 5, in the moisture sensor 3 according to the present embodiment, the insulating layer 303 is disposed on the other part of the coating layer 130 that does not overlap with the sensing electrode 200 and is disposed in contact with the embodiment of FIG. It is different from the example.

In this case, the insulating layer 303 may partially contact the side surface of the sensing electrode 200 .

6 is a cross-sectional view of a moisture sensor according to another embodiment of the present invention, showing a position corresponding to that of FIG. 2 .

Referring to FIG. 6, in the moisture sensor 4 according to the present embodiment, the conductive elastic layer 404 extends to partially contact the top surface of the insulating layer 303 and the side surface of the sensing electrode 200. It is different from the example.

That is, the conductive elastic layer 404 may be disposed on the sensing electrode 200 and may have a larger upper surface area than a portion of the sensing electrode 200 exposed without being covered by the insulating layer 303 . Accordingly, the conductive elastic layer 404 may at least partially overlap the sensing electrode 200 in the third direction (Z). As a non-limiting example, the conductive elastic layer 404 may completely cover the exposed side surface of the sensing electrode 200 .

According to this embodiment, it is possible to prevent the sensing electrode 200 from directly contacting the user's skin. For example, the right end of the left sensing electrode 200 and the left end of the right sensing electrode 200 in FIG. 6 may be portions through which current is conducted from the user's skin. At this time, user convenience can be enhanced by covering the sensing electrode 200 using the conductive elastic layer 404 having elasticity.

Figure 7 is a cross-sectional view of a moisture sensor according to another embodiment of the present invention, a cross-sectional view showing a position corresponding to Figure 2.

Referring to FIG. 7, the moisture sensor 5 according to this embodiment is different from the embodiment of FIG. 6 in that the insulating layer 305 is interposed between the side surface of the sensing electrode 200 and the conductive elastic layer 405. am.

8 is a cross-sectional view of a moisture sensor according to another embodiment of the present invention, showing a position corresponding to that of FIG. 2 .

Referring to FIG. 8 , the moisture sensor 6 according to the present embodiment has a hole penetrating the base substrate 100 and further includes a rear electrode 500 inserted into the hole, unlike the embodiment of FIG. 7 . that is different.

In the moisture sensor according to the above-described embodiments, the upper surface of the sensing electrode (based on cross-sectional view) faces the user's skin, and at the same time, the upper surface of the sensing electrode not covered by the insulating layer functions as a connection part for connecting to the processor. However, depending on the shape of the skin condition monitoring device, it may be difficult for the upper surface of the sensing electrode to function as a connection part.

Accordingly, in the moisture sensor 6 according to the present embodiment, the upper surface of the sensing electrode 200 faces the user's skin, and the lower surface of the sensing electrode 200 passes through the base substrate 100 through the rear electrode 500, and current can be configured to conduct.

Although not shown in a cross-sectional view, the rear electrode 500 may at least partially overlap the conductive elastic layer 405 in the third direction (Z).

Hereinafter, a method for manufacturing a moisture sensor according to the present invention will be described.

9 to 12 are cross-sectional views illustrating a method of manufacturing a moisture sensor according to an embodiment of the present invention, and are cross-sectional views showing positions corresponding to those of FIG. 2 .

First, referring to FIG. 9 , a base substrate is prepared by forming a coating layer 130 on the base 110 . Since the materials of the base 110 and the coating layer 130 have been described above, overlapping descriptions will be omitted. A method of forming the coating layer 130 is not particularly limited, but coating, immersion, thermal compression or melt compression may be used.

Subsequently, further referring to FIG. 10 , a sensing electrode 200 is formed on the coating layer 130 . As described above, the sensing electrode 200 may be formed by using deposition or by applying a metal paste.

Subsequently, further referring to FIG. 11 , an insulating layer 300 is partially formed on the sensing electrode 200 . Specifically, the insulating layer 300 may be disposed on the upper surface of the sensing electrode 200, except for a portion of the sensing electrode 200 that is close to the user's skin and a portion to be connected to a processor. The insulating layer 300 may or may not be disposed on the coating layer 130 .

Subsequently, referring to FIG. 12 , a conductive elastic layer 404 is formed on a portion of the exposed sensing electrode 200 not covered by the insulating layer 300 . The conductive elastic layer 404 may contact the upper and/or side surfaces of the sensing electrode 200 . Also, the conductive elastic layer 404 may contact the side surface and/or the top surface of the insulating layer 300 .

13 to 16 are cross-sectional views illustrating a method of manufacturing a moisture sensor according to another embodiment of the present invention, and are cross-sectional views showing positions corresponding to those of FIG. 2 .

First, referring to FIG. 13 , a sensing electrode 200 is formed on a base substrate including a base 110 and a coating layer 130 .

Next, referring to FIG. 14 , an insulating layer 305a is formed on the sensing electrode 200 . The insulating layer 305a may be disposed on the entire surface of the moisture sensor.

Next, referring to FIG. 15 , an opening is formed by partially removing the insulating layer 305 . The opening may overlap the sensing electrode 200 . Specifically, the opening may be formed in a portion of the sensing electrode 200 that is close to the user's skin and a portion to be connected to a processor or the like.

Subsequently, referring to FIG. 16 , a conductive elastic layer 405 is formed on a portion of the exposed sensing electrode 200 that is not covered by the insulating layer 305, that is, on a portion of the opening.

17 to 21 are cross-sectional views showing a manufacturing method of a moisture sensor according to another embodiment of the present invention, and are cross-sectional views showing positions corresponding to those of FIG. 2 .

First, referring to FIG. 17 , a sensing electrode 200 and an insulating layer 305a are formed on a base substrate including a base 110 and a coating layer 130 .

Referring next to FIG. 18 , the insulating layer 306 is partially removed to form an opening. The opening may overlap the sensing electrode 200 . Specifically, an opening may be formed in a portion of the sensing electrode 200 that is close to the user's skin.

Subsequently, referring to FIG. 19 , a conductive elastic layer 405 is formed on a portion of the exposed sensing electrode 200 that is not covered by the insulating layer 306, that is, in the opening.

Subsequently, referring to FIG. 20 , holes H are formed in the base 110 and the coating layer 130 . The hole H may be penetrated from the bottom side of the base 110, and the width may gradually decrease from the base 110 toward the coating layer 130. The hole H may have a circular shape on a plane, but the present invention is not limited thereto.

Next, referring to FIG. 21 , the back electrode 500 is inserted into the hole H. In this embodiment, after disposing the conductive elastic layer 405, the hole H is formed and the rear electrode 500 is formed, but in another embodiment, the hole H is the conductive elastic layer 405 It may be formed before placing the .

Hereinafter, the present invention will be described in more detail with reference to experimental examples.

<Production Example>

The surface of the nonwoven fabric was coated by hot-melt compression of polyurethane on the nonwoven fabric. Then, a pair of sensing electrodes was prepared by applying silver (Ag) paste in a line shape on the top. Then, an insulating layer was formed on the sensing electrode using polyurethane. The insulating layer was formed to partially expose the sensing electrode.

Then, an adhesive conductive layer was formed on the upper surface of the exposed sensing electrode. The adhesive conductive layer was prepared by mixing silver (Ag) particles having an average particle size of about 40 μm with a silicon polymer. The content of the silver particles was 15.0 wt%. The prepared adhesive conductive layer had a slight stickiness and excellent adhesion to the skin. The manufactured moisture sensor is shown in FIG. 22 .

<Comparative example>

A moisture sensor was prepared in the same manner as in Preparation Example, except that the conductive adhesive layer was not formed on the sensing electrode.

<Experimental Example 1>

An operation of completely folding the adhesive conductive layer, that is, the conductive elastic layer portion of the moisture sensor prepared in Manufacturing Example was performed 100 times. Then, impedance was measured on the pig skin surface using a repeatedly bent moisture sensor. And the result is shown in FIG. 23.

Referring to FIG. 23, it can be seen that the impedance change is clearly measured according to the amount of moisture on the skin surface.

<Experimental Example 2>

Completely folding the conductive elastic layer portion of the moisture sensor prepared in Manufacturing Example and Comparative Example was performed 100 times. Then, impedance was measured on the simulated pig skin surface under the same conditions. The measured moisture content of the pig skin surface was about 50%. This was repeated several times. And the results are shown in FIG. 24 .

Referring to FIG. 24 , in the case of the manufacturing example (left), a relatively accurate impedance value can be measured despite repeated measurements. On the other hand, in the case of the comparative example (right), it can be confirmed that the measured impedance values are different and unreliable according to repeated measurements. In addition, there was difficulty in the experiment due to lack of adhesion to the simulated skin. In particular, in the moisture sensor according to the comparative example, a crack that can be confirmed with the naked eye occurred at the conductive portion, and accordingly, it is estimated that the impedance also greatly increased compared to the manufacturing example.

Although the above has been described with reference to the embodiments of the present invention, this is only an example and does not limit the present invention, and those skilled in the art in the field to which the present invention belongs will It will be appreciated that various modifications and applications not exemplified above are possible.

Therefore, it should be understood that the scope of the present invention includes modifications, equivalents, or substitutes of the technical ideas exemplified above. For example, each component specifically shown in the embodiment of the present invention can be modified and implemented. And the differences related to these modifications and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

1: moisture sensor
100: base material
110: base
130: polymer coating layer
200: sensing electrode
300: insulating layer
400: conductive elastic layer

Claims (15)

one or more sensing electrodes disposed on the base; and
Moisture sensor comprising a conductive elastic layer disposed at least partially directly on the sensing electrode. According to claim 1,
a polymer coating layer disposed between the base and the sensing electrode; and
Moisture sensor further comprising an insulating layer disposed at least partially in contact with the side surface of the sensing electrode. According to claim 2,
The polymer coating layer contains 80% or more of a polyurethane-based polymer,
The base is a moisture sensor that is a fiber base having flexibility and air permeability. According to claim 1,
The sensing electrode includes silver (Ag),
The conductive elastic layer is a moisture sensor that is a conductive silicone layer containing silicon. According to claim 1,
The conductive elastic layer is a moisture sensor comprising silicon and metallic particles having an average particle size in the range of 5㎛ to 50㎛ dispersed in the silicon. According to claim 1,
A moisture sensor further comprising an insulating layer disposed at least partially on the sensing electrode, wherein the insulating layer is in contact with the conductive elastic layer. According to claim 6,
The insulating layer is at least partially interposed between the sensing electrode and the conductive elastic layer. According to claim 6,
The conductive elastic layer is at least partially in contact with the upper surface of the insulating layer and the side surface of the sensing electrode moisture sensor. According to claim 1,
A moisture sensor further comprising a rear electrode that penetrates the base and is in conduction with the sensing electrode, wherein the rear electrode overlaps the conductive elastic layer. According to claim 1,
The modulus of the conductive elastic layer is a moisture sensor in the range of 0.1 MPa to 1.5 MPa. placing one or more sensing electrodes on the base;
A method of manufacturing a moisture sensor comprising disposing a conductive elastic layer at least partially on the sensing electrode. According to claim 11,
Method of manufacturing a moisture sensor further comprising disposing an insulating layer at least partially on the sensing electrode before disposing the conductive elastic layer. According to claim 12,
The method of manufacturing a moisture sensor further comprising exposing an upper surface of the sensing electrode by partially removing the insulating layer before disposing the conductive elastic layer. Skin monitoring device comprising a moisture sensor according to claim 1. According to claim 14,
The skin monitoring device includes at least one of a mask pack, a wound covering material, and a diaper.

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