COOLING DEVICE AND METHOD FOR MANUFACTURING THE SAME

Abstract

Provided is a cooling device including opening/closing holes disposed in one side thereof and a cavity. Each of the opening/closing holes is actively opened and closed according to a temperature of an external heat source, and the cavity is connected to the outside of the cooling device through the opening/closing holes.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This U.S. non-provisional patent application claims priority under 35 U.S.C. §119 of Korean Patent Application No. 10-2015-0130452, filed on Sep. 15, 2015, the entire contents of which are hereby incorporated by reference.

BACKGROUND

The present disclosure herein relates to a cooling device, and more particularly, to a cooling device actively adjusting cooling efficiency.

Heat is generated in all systems including electronic devices and biological tissues. When the heat is not released, in case of the electronic devices, a circuit may be burnt or deteriorated to decrease its performance, and, in case of the biological tissues, protein may be denaturalized not to perform its function. Thus, to prevent the above-described phenomenon, a cooling system needs to be applied to actively release the heat to the outside, thereby maintaining a temperature. Especially, when the cooling system is grafted onto advanced concept technologies such as IoT industry and thermoelectric generation using a body temperature, the cooling system optimized to the above-described environment needs to be newly developed. The cooling system is desired to be set up in an environment in which various curvatures such as a human body or a complex electric circuit, and manufactured in a thin film shape for integration or convenience. Manufacturing technologies of the cooling system in which the entire system is miniaturized to be attachable or wearable are required. In terms of the above-described features, most of the currently developed cooling system may not be applied to new technologies.

SUMMARY

The present disclosure provides a cooling device in which an inlet of a cavity is actively opened/closed.

However, the above-described cooling device is described as an example. Thus, the present disclosure is not limited to the above-described cooling device.

An embodiment of the inventive concept provides a cooling device including opening/closing holes disposed in one side thereof and a cavity. Each of the opening/closing holes is actively opened and closed according to a temperature of an external heat source, and the cavity is connected to the outside of the cooling device through the opening/closing holes.

In an embodiment, when viewed from a plan view, each of the opening/closing holes may have one of a circular shape and a triangular shape.

In an embodiment, when viewed from a plan view, a configuration of each of the opening/closing holes may include a first portion extending in a first direction, a second portion extending from one end area of the first portion in a second direction perpendicular to the first direction, and a third portion extending from the other end area of the first portion in a third direction that is perpendicular to the first direction and opposite to the second direction.

In an embodiment, when viewed from a plan view, the opening/closing holes may be spaced apart from each other, and the spaced distance may correspond to a half of a size of each of the opening/closing holes.

In an embodiment, the cooling device may further include a temperature-responsive polymer.

In an embodiment, the temperature-responsive polymer may include poly(N-isopropylacrylamide).

In an embodiment, the cavity may be provided in plurality.

In an embodiment of the inventive concept, a method for manufacturing a cooling device, the method includes: providing resist on a substrate; pressing the resist by a mold to form a first portion; bonding a second portion having a plate shape to a lower portion of the first portion. Each of the first portion and the second portion includes a temperature-responsive polymer, the cooling device includes opening/closing holes disposed in one side thereof and a cavity, the opening/closing holes are actively opened and closed according to a temperature of an external heat source, and the cavity is connected to the outside of the cooling device through the opening/closing holes.

In an embodiment, the resist may be ultraviolet (UV) resist, and the forming of the first portion may further include irradiating UV rays to the resist to cure the resist.

In an embodiment, the resist may include poly(N-isopropylacrylamide).

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings are included to provide a further understanding of the inventive concept, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the inventive concept and, together with the description, serve to explain principles of the inventive concept. In the drawings:

FIG. 1 is a plan view of a cooling device according to an embodiment of the inventive concept;

FIG. 2 is a cross-sectional view of the cooling device taken along line A1-A2 in FIG. 1 according to an embodiment of the inventive concept;

FIGS. 3 and 4 are perspective views for explaining an operation of the cooling device according to an embodiment of the inventive concept;

FIG. 5 is a plan view for explaining a mold used for a method for manufacturing the cooling device according to an embodiment of the inventive concept;

FIG. 6 is a cross-sectional view taken along line B1-B2 of FIG. 5 for explaining the mold used for the method for manufacturing the cooling device according to an embodiment of the inventive concept;

FIGS. 7 and 8 are cross-sectional views taken along line B 1-B2 of FIG. 5 for explaining the method for manufacturing the cooling device according to an embodiment of the inventive concept; and

FIGS. 9 and 10 are plan views of a cooling device according to another embodiment of the inventive concept.

DETAILED DESCRIPTION

The objects, other objectives, features, and advantages of the inventive concept will be understood without difficulties through preferred embodiments below related to the accompanying drawings. The present disclosure may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.

In this specification, it will also be understood that when another component is referred to as being ‘on’ one component, it can be directly on the one component, or an intervening third component may also be present. Also, though terms like a first, a second, and a third are used to describe various regions and layers in various embodiments of the inventive concept, the regions and the layers are not limited to these terms. These terms are only used to distinguish one component from another component. Therefore, a portion referred to as a first portion in one embodiment can be referred to as a second portion in another embodiment. An embodiment described and exemplified herein includes a complementary embodiment thereof. Like reference numerals refer to like elements throughout.

FIG. 1 is a plan view of a cooling device according to an embodiment of the inventive concept. FIG. 2 is a cross-sectional view of the cooling device taken along line A1-A2 in FIG. 1 according to an embodiment of the inventive concept.

Referring to FIGS. 1 and 2, a storage part 100 including a cavity 110 may be provided. The storage part 100 may include an opening part 120 defined in an upper portion thereof. For example, the cavity 110 of the storage part 100 may have a cylindrical shape. For example, the cavity 110 of the storage part 100 may have a diameter of about 500 μm and a height of about 200 μm. The diameter of the cavity 110 of the storage part 100 may represent a diameter of a bottom of the cavity 110. The height of the cavity 110 of the storage part 100 may represent a shortest distance from the bottom of the cavity 110 to the opening part 120. An embodiment of the inventive concept is not limited to the shape of the cavity 110 of the storage part 100. An outer surface 130 of the storage part 100 may be an area contacting a heat source. For example, a bottom surface of the outer surface 130 of the storage part 100 may contact a skin, an electronic circuit, or human organs (e.g., a heart). A position of the heat source is not limited to the bottom surface. The position may be determined by an object to be applied according to an embodiment of the inventive concept. The storage part 100 may have a flexible property. Accordingly, the cooling device according to an embodiment of the inventive concept may be disposed on an uneven surface. The storage part 100 may include the same material as that of an opening/closing part that will be described later. For example, the storage part 100 may include one selected from the group consisting of poly(N-isopropylacrylamide), hydroxypropylcellulose, poly(N-vinyllactam), polyvinyl methyl ether, and a combination thereof.

A refrigerant may be provided in the storage part 100. For example, the refrigerant may be provided in the storage part 100 by a method for dipping the cooling device according to an embodiment of the inventive concept in the refrigerant. The refrigerant may absorb heat of an external heat source and be evaporated. The refrigerant may cool the external heat source through the evaporation of the refrigerant. For example, the refrigerant may be water. The water may be naturally evaporated in a general living environment (i.e., relative humidity of about 50%, about 25° C., and flow velocity of about 1.5 m/s). When the water is used as the refrigerant of the cooling device according to an embodiment of the inventive concept, the water may cool heat that is two or three times greater than a heating amount (about 10 mW/cm²) of a human body through the natural evaporation. An amount of water consumed by evaporation in the cooling device according to an embodiment of the inventive concept may be about 60 μL/min·cm².

The opening/closing part 200 may be provided on the storage part 100. The opening/closing part 200 may cover the opening part 120 of the storage part 100. The opening/closing part 200 may have a plate shape. The opening/closing part 200 may have a flexible property. Accordingly, the cooling device according to an embodiment of the inventive concept may be disposed on an uneven surface. For example, the opening/closing part 200 may include a temperature responsive material that absorbs or releases the refrigerant according to a temperature. For example, the opening/closing part 200 may include one selected from the group consisting of poly(N-isopropylacrylamide), hydroxypropylcellulose, poly(N-vinyllactam), polyvinyl methyl ether, and a combination thereof. For another example, the opening/closing part 200 may include an electrosensitive polymer (e.g., polypyrrole).

Opening/closing holes 210 passing through the opening/closing part 200 may be provided. When viewed from a plan view, each of the opening/closing holes 210 may have a circular shape. Each of the opening/closing holes 210 may have a diameter of about 20 μm. When viewed from a plan view, the opening/closing holes 210 may be spaced apart from each other. For example, a spaced distance between the most adjacent opening/closing holes 210 may correspond to a half of a radius of each of the opening/closing holes 210. The cavity 110 of the storage part 100 may be connected to the outside through the opening/closing holes 210. The opening/closing holes 210 may be actively closed and opened according to temperature variation. That is, the opening/closing holes 210 may be opened when the temperature increases and closed when the temperature decreases. Reference of temperature with respect to opening/closing of the opening/closing holes 210 may be varied according to a material constituting the opening/closing parts 200. For example, when the opening/closing part 200 includes poly(N-isopropylacrylamide), the refrigerant may be discharged when the temperature of the opening/closing part 200 is greater than about 32° C., and the refrigerant may be absorbed when the temperature of the opening/closing part 200 is less than about 32° C. The opening/closing part 200 may be contracted when the refrigerant is discharged and expanded when the refrigerant is absorbed. Accordingly, the opening/closing holes 210 may be opened when the temperature of the opening/closing parts 200 is greater than about 32° C. and closed when the temperature of the opening/closing parts 200 is less than about 32° C. The above-described opening/closing may represent partial opening/closing as well as complete opening/closing. The opening/closing part 200 contracted/expanded depending on the temperature is described as an example. In another example, the opening/closing part 200 may be contracted/expanded by other factors (e.g., electricity) instead of the temperature.

According to the embodiment of the inventive concept, the cooling device including the opening/closing holes 210 that are opened/closed may be provided. The opening/closing holes 210 is further opened to increase cooling efficiency when a temperature of the heat source is high, and the opening/closing holes 210 is further closed to decrease the cooling efficiency when the temperature of the heat source is low. The above-described process may be actively performed according to the temperature.

Hereinafter, operation of the cooling device according to an embodiment of the inventive concept will be described.

FIGS. 3 and 4 are perspective views illustrating the operation of the cooling device according to an embodiment of the inventive concept. For simplicity of description, description for contents that are substantially the same as those described with reference to FIGS. 1 and 2 will not be provided. Although the opening/closing parts 200 including the poly(N-isopropylacrylamide) is described, an embodiment of the inventive concept is not limited to the material of the opening/closing parts 200. Although the opening/closing parts 200 opened/closed depending on the temperature are described, an embodiment of the inventive concept is not limited thereto.

Referring to FIG. 3, the opening/closing holes 210 may be opened through discharging the refrigerant. As described above by referring to FIGS. 1 and 2, the present operation may be performed when the temperature of the cooling device according to an embodiment of the inventive concept is greater than about 32° C. When the opening/closing holes 210 are opened, the refrigerant in a vapor state is discharged to increase the cooling efficiency.

Hereinafter, a cooling process of the cooling device according to an embodiment of the inventive concept will be described. Although not shown, the refrigerant (e.g., water) may be provided in the storage part. The refrigerant may receive heat from the heat source through the cooling device. The refrigerant may be evaporated to be converted into vapor (e.g., water vapor). The vapor of the refrigerant may be discharged to the outside of the cooling device through the opening/closing holes 210.

Referring to FIG. 4, the opening/closing holes 210 may be further closed than the opening/closing holes 210 in FIG. 3. As described above by referring to FIGS. 1 and 2, the present operation may be performed when the temperature of the cooling device is less than about 32° C. When the opening/closing holes 210 is further closed than the opening/closing holes 210 in FIG. 3, the discharging of the vapor of the refrigerant may be reduced to decrease the cooling efficiency further than that of the case described with reference to FIG. 3.

Hereinafter, a method for manufacturing the cooling device according to an embodiment of the inventive concept will be described. Although a method manufactured by nano-imprinting is described, an embodiment of the inventive concept is not limited thereto.

FIG. 5 is a plan view for explaining a mold used for the method for manufacturing the cooling device. FIG. 6 is a cross-sectional view taken along line B1-B2 of FIG. 5 for explaining the mold used for the method for manufacturing the cooling device.

Referring to FIGS. 5 and 6, the nano-imprinting mold 300 may be provided. The mold 300 may include a body part 310 and protruding parts 320 disposed on the body part 310. The body part 310 may form the cavity 110 of the storage part 100 of the cooling device described with reference to FIGS. 1 and 2. Although the body part 310 having a cylindrical shape is illustrated, an embodiment of the inventive concept is not limited thereto. For example, the body part 310 may have a diameter of about 500 μm and a height of about 200 μm. The protruding part 320 may form the opening/closing holes 210 of the cooling device described with reference to FIGS. 1 and 2. Although the protruding part 320 having a cylindrical shape is illustrated, an embodiment of the inventive concept is not limited thereto. For example, each of the protruding parts 320 may have a diameter and height of about 20 μm.

FIGS. 7 and 8 are cross-sectional views taken along line B1-B2 of FIG. 5 for explaining the method for manufacturing the cooling device according to an embodiment of the inventive concept.

Referring to FIG. 7, a first portion 420 of the cooling device may be formed by the nano-imprinting process. The nano-imprinting process may include thermal imprinting or UV-based imprinting process. Hereinafter, a process for forming the cooling device according to an embodiment of the inventive concept through the UV imprinting process will be described. Resist may be provided on a substrate 410. For example, the manufacturing process of the resist may be a coating process. The resist may have viscosity. For example, the resist may include a temperature-responsive material. For example, although the resist may include one selected from the group consisting of poly(N-isopropylacrylamide), hydroxypropylcellulose, poly(N-vinyllactam), polyvinyl methyl ether, and a combination thereof, an embodiment of the inventive concept is not limited thereto.

The molds 300 described with reference to FIG. 5 may be provided on the substrate 410. Each of the molds 300 may have a top surface contacting a top surface of the substrate 410. The resist may be provided between the molds 300 and the substrate 410. The resist may be irradiated by UV rays. The resist may be cured to form the first portion 420 of the cooling device. The opening/closing holes 210 of the cooling device described with reference to FIGS. 1 and 2 may be formed through the protruding parts 320 of the mold 300. The cavity 110 of the cooling device may be formed through the body part 310 of the mold 300. The mold 300 and the substrate 410 may be cooled. The mold 300 and the substrate 410 may be pressed in a direction away from the first portion 420 of the cooling device and separated from the first portion 420 of the cooling device.

Referring to FIG. 8, a second portion 430 of the cooling device may be provided. The second portion 430 of the cooling device may have a plate shape. The second portion 430 of the cooling device may be bonded below the first portion 420 of the cooling device. The bonding may be performed by using available bonding units such as heat or laser. The second portion 430 of the cooling device may be substantially the same as a lower portion of the storage part 110 of the cooling device described with reference to FIGS. 1 and 2. According to an example, the second portion 430 of the cooling device may include the same temperature-responsive material as that of the first portion 420 of the cooling device. For example, the second portion 430 of the cooling device may include one selected from the group consisting of poly(N-isopropylacrylamide), hydroxypropylcellulose, poly(N-vinyllactam), polyvinyl methyl ether, and a combination thereof.

FIGS. 9 and 10 are plan views of a cooling device according to another embodiment of the inventive concept. For simplicity of description, description for contents that are substantially the same as those described with reference to FIGS. 1 to 8 will not be provided.

Referring to FIG. 9, the cooling device according to an embodiment may be substantially the same as the cooling device described with reference to FIGS. 1 and 2, except for shapes of the opening/closing holes 212. When viewed from a plan view, each of the opening/closing holes 212 according to an embodiment may have a triangular shape. Although the six opening/closing holes 212 according to an embodiment are illustrated as an example, an embodiment of the inventive concept is not limited to the number of the opening/closing holes 212. The method for manufacturing the cooling device according to an embodiment may be substantially the same as that of the cooling device described with reference to FIGS. 5 to 8, except for the protruding part of the mold. When viewed from a plan view, each of the protruding parts of the mold according to an embodiment may have a triangular shape.

Referring to FIG. 10, the cooling device according to an embodiment may be substantially the same as the cooling device described with reference to FIGS. 1 and 2, except for shapes of the opening/closing holes 214. When viewed from a plan view, each of the opening/closing holes 214 according to an embodiment may have a Z shape. The Z shape may represent a shape similar to Z as well as the same shape as Z. For example, the Z shape may have a shape in which a middle line connecting two parallel lines of Z is perpendicular to the two parallel lines. Although the nine opening/closing holes 214 according to an embodiment are illustrated as an example, an embodiment of the inventive concept is not limited to the number of the opening/closing holes 214. The method for manufacturing the cooling device according to an embodiment may be substantially the same as that of the cooling device described with reference to FIGS. 5 to 8, except for the protruding part of the mold. When viewed from a plan view, each of the protruding parts of the mold according to an embodiment may have the above-described Z shape.

According to the embodiment of the inventive concept, the cooling device including the opening/closing hole that is actively opened/closed may be provided.

However, the effects of the embodiment of the inventive concept are not limited to the above-described contents.

Until now, preferred embodiments of the present invention are mainly described. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the preferred embodiments should be considered in descriptive sense only and not for purposes of limitation. Therefore, the scope of the invention is defined not by the detailed description of the invention but by the appended claims, and all differences within the scope will be construed as being included in the present invention.

Claims

1. A cooling device comprising opening/closing holes disposed in one side thereof and a cavity,

wherein each of the opening/closing holes is actively opened and closed according to a temperature of an external heat source, and the cavity is connected to the outside of the cooling device through the opening/closing holes.

2. The cooling device of claim 1, wherein, when viewed from a plan view, each of the opening/closing holes has one of a circular shape, a Z shape and a triangular shape.

3. The cooling device of claim 1, wherein, when viewed from a plan view, a configuration of each of the opening/closing holes comprises a first portion extending in a first direction, a second portion extending from one end area of the first portion in a second direction perpendicular to the first direction, and a third portion extending from other end area of the first portion in a third direction that is perpendicular to the first direction and opposite to the second direction.

4. The cooling device of claim 1, wherein, when viewed from a plan view, the opening/closing holes are spaced apart from each other, and

the spaced distance between the opening/closing holes corresponds to a half of a size of each of the opening/closing holes.

5. The cooling device of claim 1, further comprising a temperature-responsive polymer.

6. The cooling device of claim 5, wherein the temperature-responsive polymer comprises poly(N-isopropylacrylamide).

7. The cooling device of claim 1, wherein the cavity is provided in plurality.

8. A method for manufacturing a cooling device, the method comprising:

providing resist on a substrate;

pressing the resist by a mold to form a first portion;

bonding a second portion having a plate shape to a lower portion of the first portion,

wherein each of the first portion and the second portion comprises a temperature-responsive polymer, the cooling device comprises opening/closing holes disposed in one side thereof and a cavity, the opening/closing holes are actively opened and closed according to a temperature of an external heat source, and the cavity is connected to the outside of the cooling device through the opening/closing holes.

9. The method of claim 8, wherein the resist is ultraviolet (UV) resist, and

the forming of the first portion further comprises irradiating UV rays to the resist to cure the resist.

10. The method of claim 8, wherein the resist comprises poly(N-isopropylacrylamide).