KR101781540B1 - Dry adhesive structure and method for forming the same - Google Patents

Abstract

A dry adhesive structure and a method of forming the same are provided. Wherein the dry adhesion structure includes a body portion having a first surface and a second surface facing each other and an adhesive portion disposed on the first surface, wherein the adhesive portion has an annular cross section in a direction parallel to the first surface . The method for forming a dry adhesion structure is characterized in that a first polymer is provided on a hole pattern mold having holes, and then the first polymer, which is in contact with the upper surface of the hole pattern mold, is removed to form a hole pattern mold Forming a polymer structure pattern by etching the polymer structure; providing a second polymer on the hole pattern mold on which the structure pattern is formed and separating the polymer to form a preliminary polymer mold; Forming a polymer mold by providing a third polymer on the preliminary polymer mold and separating the polymer, and separating the polymer after providing the fourth polymer on the polymer mold.

Description

[0001] DRY ADHESIVE STRUCTURE AND METHOD FOR FORMING THE SAME [0002]

The present invention relates to a dry bonding structure and a method of forming the same.

Studies on dry adhesives and wet adhesives mimicking the living body in the natural world are actively being conducted. In particular, dry adhesives based on lizard feet and chemical adhesives derived from shellfish proteins have recently been proposed as biomimetic adhesives. However, the adhesives have a problem in that the adhesiveness to the skin of a person repeatedly exposed to tension and compression is weak, so that they easily fall off after adhesion, or are difficult to reuse once after use.

Meanwhile, the conventional skin patch was mainly used as a means for manually releasing a drug to the human body. However, recently, an electronic device for releasing various sensors or drugs has been installed in such a patch to develop a medical electronic patch such as diagnosis and treatment Research is underway. However, conventional electronic patches on which electronic devices and the like are mounted have a limited ability to be commercialized due to poor adhesion to human skin. When a chemical adhesive is used to increase the adhesive strength, the skin is damaged when it is attached to the skin after it is separated from the skin, is not reusable, and is expensive, which is not practical.

In order to solve the above-mentioned problems, the present invention provides a dry adhesive structure having excellent adhesive strength and being reusable.

The present invention provides a dry bonding structure excellent in biocompatibility.

The present invention provides a method of forming the dry adhesion structure.

Other objects of the present invention will become apparent from the following detailed description and the accompanying drawings.

The dry adhesion structure according to embodiments of the present invention includes a body portion having a first surface and a second surface facing each other, and an adhesive portion disposed on the first surface. Wherein the adhesion portion has a ring-shaped cross section in a direction parallel to the first surface, and a suction cup-shaped or crater-shaped adhesion space recessed in the adhesion portion is defined, And the aspect ratio of the adhering portion indicating the ratio of the height of the adhering portion to the diameter of the adhering portion is less than 1.

The diameter of the bonding portion is 500 to 1,500 nm, the height of the bonding portion is 50 to 150 nm, the aspect ratio of the bonding portion is 1/30 to 3/10, and the height of the bonding space may be 50 to 250 nm.

The body portion may include a first body portion connected to the adhesive portion and a second body portion disposed below the first body portion, and the first body portion and the second body portion may have different moduli.

The modulus of the dry adhesion structure may be reduced from the first surface to the second surface.

The dry adhesion structure may be formed of a polymer, and the modulus of the dry adhesion structure may be controlled by adjusting the content of the polymer and the curing agent of the polymer.

The body portion and the adhesive portion may be integrally formed.

The dry adhesion structure may be formed of polydimethylsiloxane.

A method of forming a dry adhesion structure according to embodiments of the present invention includes providing a first polymer on a hole pattern mold having holes, removing the first polymer contacting the upper surface of the hole pattern mold, Forming a polymer structure that is disposed on the hole pattern mold and protrudes above the hole pattern mold; forming a polymer structure pattern by etching the polymer structure; providing a second polymer on the hole pattern mold on which the structure pattern is formed Separating the polymer to form a preliminary polymer mold, providing a third polymer on the preliminary polymer mold and separating the polymer to form a polymer mold, and separating after providing the fourth polymer on the polymer mold.

The first polymer may have etching selectivity with respect to the hole pattern mold.

A recess region may be formed between the side surface of the hole and the polymer structure pattern by the etching.

The height of the recessed region may be 50 to 150 nm.

The aspect ratio of the hole is 3 or more, and the side surface of the hole may have a wavy shape.

The first to third polymers may be polyurethane acrylate, and the fourth polymer may be polydimethylsiloxane.

The fourth polymer may be provided with a fifth polymer on the fourth polymer before the fourth polymer is separated from the hole pattern mold, and the fourth polymer and the fifth polymer may have different moduli.

The modulus can be controlled by controlling the content of the curing agent contained in the fourth polymer and the fifth polymer.

The dry adhesive structure according to the embodiments of the present invention has excellent adhesive strength and can be reused without using a chemical adhesive. The dry adhesion structure can maintain the adhesive force even when used repeatedly. The dry adhesion structure is excellent in biocompatibility and does not cause skin damage even if it is detached after adhering to a living body skin. The dry adhesive structure has a simple manufacturing process and low manufacturing cost.

The electronic patch according to embodiments of the present invention can be conformably and stably attached to the living body skin through the dry bonding structure. Thereby, the electronic patch can accurately measure the biological signal. The electronic patch is stuck to the living body skin and can be stably operated even when repeatedly exposed to tension and compression. Since the ultra-thin electronic sensors are integrated conformationally, the electronic patch can continuously and physically and physiologically monitor signals with high sensitivity.

The bio-signal monitoring system according to embodiments of the present invention can accurately measure various physiological signals such as pulse, blood pressure, electrocardiogram, behavioral progress, respiration, and body temperature in real time. Physiological signal data can be transmitted and managed in real time, and alert signals can be transmitted to hospitals, emergency centers, and / or rescue centers through external devices such as tablets or smart phones when a biomedical signal or malfunction signal is detected have. In addition, the transdermal delivery rate of the drug can be controlled by an electric osmotic method or the like in response to an instruction from an external device.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1A shows a dry bonding structure according to an embodiment of the present invention.
Figure 1b shows the section of Figure 1a.
Figure 2 shows a dry adhesion structure according to another embodiment of the present invention.
FIG. 3A shows an AFM image of a dry adhesive structure according to an embodiment of the present invention, and FIG. 3B shows tentacles and suckers of cephalopod animals.
4 shows an SEM image of a dry adhesion structure according to an embodiment of the present invention and a dry adhesion structure according to a comparative example.
5A to 10B show a method of forming the dry adhesion structure of FIG.
11 and 12 show a method of forming the dry adhesion structure of Fig.
13 schematically shows a process of forming a dry adhesion structure according to an embodiment of the present invention.
14 is an exploded perspective view of an electronic patch according to an embodiment of the present invention.
15A to 15H are views for explaining transdermal drug delivery using the electroosmotic method according to an embodiment of the present invention.
16 to 18 show a method of forming an electronic patch according to an embodiment of the present invention.
19 schematically shows a process of forming an electronic patch according to an embodiment of the present invention.
Fig. 20 is a graph showing the difference in adhesive force between the electronic patches having different adhesive structures.
FIG. 21 shows an image in which an electronic patch, to which a dry bonding structure according to an embodiment of the present invention is coupled, and an electronic patch to which a conventional dry bonding structure is bonded, is bonded to the skin mold.
Figure 22 shows the system modulus of various electronic patches.
FIGS. 23A to 23I show results of applying an electronic patch according to an embodiment of the present invention to an experimental rat.
24A to 24G are views for explaining measurement of a living body signal using an electronic patch according to an embodiment of the present invention.
25 shows a bio-signal monitoring system according to an embodiment of the present invention.
26 schematically shows a configuration of a smart band according to an embodiment of the present invention.
27 shows a schematic diagram of a circuit for real-time sensing, wireless data transmission, and remote control.
28A and 28B show application examples of a bio-signal monitoring system according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to examples. The objects, features and advantages of the present invention will be easily understood by the following embodiments. The present invention is not limited to the embodiments described herein, but may be embodied in other forms. The embodiments disclosed herein are provided so that the disclosure may be thorough and complete, and that those skilled in the art will be able to convey the spirit of the invention to those skilled in the art. Therefore, the present invention should not be limited by the following examples.

Although the terms first, second, etc. are used herein to describe various elements, the elements should not be limited by such terms. These terms are only used to distinguish the elements from each other. In addition, when an element is referred to as being on another element, it may be directly formed on the other element, or a third element may be interposed therebetween.

The sizes of the elements in the figures, or the relative sizes between the elements, may be exaggerated somewhat for a clearer understanding of the present invention. In addition, the shape of the elements shown in the drawings may be somewhat modified by variations in the manufacturing process or the like. Accordingly, the embodiments disclosed herein should not be construed as limited to the shapes shown in the drawings unless specifically stated, and should be understood to include some modifications.

[Dry adhesive structure]

1A shows a dry bonding structure according to an embodiment of the present invention, and Fig. 1B shows a cross section of Fig. 1A.

Referring to FIGS. 1A and 1B, the dry bonding structure 100 may include a body portion 110 and a bonding portion 120. The dry adhesion structure 100 may be formed of a polymeric material, for example, polydimethylsiloxane (PDMS). The body 110 and the adhesive 120 may be integrally formed. The body 110 may have a first surface 110a and a second surface 110b facing each other.

The adhesive portion 120 protrudes above the first surface 110a of the body 110 and may have an annular cross section in a direction parallel to the first surface 110a. The diameter Ds of the bonding portion 120 may be 500 to 1,500 nm. The height of the bonding portion 120 from the first surface 110a may be 50-150 nm. The aspect ratio of the bonding portion 120 indicating the ratio of the height of the bonding portion 120 from the first surface 110a to the diameter Ds of the bonding portion 120 is less than 1. The aspect ratio of the bonding portion 120 may be 1/30 to 3/10.
A suction cup shape or a crater shape adhering space 120a recessed into the inside by the adhering portion 120 can be defined. The height Hs of the adhesive space 120a may be 50 to 250 nm. The height of the adhesive space 120a is larger than the height of the adhesive portion 120. [

The dry adhesive bonding structure 100 may be adhered to an adherend substrate (not shown) through a bonding portion 120 disposed on the first surface 110a of the body portion 110, It is possible to attach the adherend to the adherend substrate while supporting the adherend (not shown) disposed on the two surfaces 110b or inside the body 110. [ For example, the adherend substrate may be human skin, and the adherend may be an electronic device capable of measuring a biological signal. But the present invention is not limited thereto, and the dry adhesive structure 100 can be adhered to various substrates to be adhered.

The dry adhesive structure 100 can be strongly adhered to the adherend substrate without using an adhesive due to the physical structure or the like of the adhering section 120 and can be desorbed repeatedly on the adherend substrate. In addition, even if the adhesion is repeated a plurality of times, the dry adhesive structure 100 can maintain a strong adhesive force.

The modulus of the dry adhesive structure 100 can be controlled by adjusting the amount of the curing agent to be mixed with the polymeric material as a constituent material thereof. The modulus of the dry adhesion structure 100 was measured with respect to the weight ratio of the PDMS used to form the dry adhesion structure 100 and the curing agent added to the PDMS, and is shown in Table 1 below.

Mixing ratio of polymer material PDMS
5: 1 PDMS
10: 1 PDMS
20: 1 PDMS
30: 1 PDMS
40: 1 Modulus (kPa) 1607 1182 516 142 39.3

Referring to Table 1, when the weight ratio of PDMS to the curing agent was 5: 1, 10: 1, 20: 1, 30: 1, 40: 1, the modulus of the dry adhesion structure 100 was 1607 kPa, 1182 kPa, 516 kPa, 142 kPa and 39.3 kPa, respectively. That is, as the amount of the curing agent added decreases, the modulus of the dry adhesion structure 100 decreases.

Figure 2 shows a dry adhesion structure according to another embodiment of the present invention. The description overlapping with the above-described embodiment may be omitted.

Referring to FIG. 2, the dry bonding structure 100 may include a body portion 110 and a bonding portion 120. The body portion 110 may include a first body portion 111, a second body portion 112, and a third body portion 113 which are sequentially stacked. For example, the second body portion 112 may be disposed on the third body portion 113, and the first body portion 111 may be disposed on the second body portion 112. The first body part 111 and the adhesive part 120 may be integrally formed.

The first body part 111, the second body part 112, and the third body part 113 may have different modulus. The modulus can be controlled by controlling the amount of the curing agent mixed with the polymer material constituting the first body part 111, the second body part 112, and the third body part 113. [ The modulus may gradually decrease from the first body part 111 to the third body part 113. [ For example, the first body portion 111 may have a modulus of about 1.6 MPa, the second body portion 112 may have a modulus of about 1.2 MPa, and the third body portion 113 may have a modulus of about 500 kPa Of modulus.

In this embodiment, the dry bonding structure 100 includes three body portions having different modulus, but it is not limited thereto and may include two or more body portions having different modulus.

FIG. 3A shows an AFM image of a dry adhesive structure according to an embodiment of the present invention, and FIG. 3B shows tentacles and suckers of cephalopod animals.

Referring to FIGS. 3A and 3B, the dry adhesive structure is designed from the tentacles of an octopus animal, and the adhesive portion of the dry adhesive structure has a structure and a shape similar to those of a sucker disposed on the tentacles of the cephalopod animals. Thus, the dry adhesive structure can have the same attraction force as the sucker of the cephalopod animal, so that the dry adhesive structure can be strongly adhered to the adherend substrate and can maintain a strong adhesive force even if the adherend is repeated.

Figure 4 shows an SEM image of a dry adhesion structure (micro suction cup) structure according to an embodiment of the present invention and a dry adhesion structure according to a comparative example (micro-pillar structure).

Referring to FIG. 4, the m-pillar structure, which is conventionally designed by mimicking the lizard foot, is formed by densely gathering a plurality of micro pillars having relatively high aspect ratios at regular intervals. The m-pillar structure increases the bonding strength by increasing the surface area, but it must have a high modulus in order to maintain its shape without tilting, bending, or collapsing. Thus, the modulus of the m-pillar structure is higher than the modulus of the skin epidermis. However, an mSC structure having a relatively low aspect ratio (height 50-150 nm, diameter 500-1500 nm) may have a lower modulus and greater adhesion force than an m-pillar structure.

[Method of forming dry adhesion structure]

FIG. 5A shows a method of forming the dry adhesion structure of FIG. FIGS. 5A and 5B are perspective views showing a process of forming the dry bonding structure, and FIGS. 5B to 10B are sectional views of FIGS. 5A to 10A, respectively.

5A and 5B, a hole pattern mold 150 having a hole 151 is prepared. The hole pattern mold 150 may be, for example, a silicon mold. The holes 151 may be arranged in two directions parallel to the upper surface of the hole pattern mold 150 and intersecting with each other. The hole 150 may have a columnar shape and may have an aspect ratio (Hh / Dh) of 3 or more. The hole side 151s may have a wavy serpentine shape.

6A and 6B, the surface of the hole pattern mold 150 is treated with FOTCS SAM (trichloro (1H, 1H, 2H, 2H-perfluorooctyl) silane self-assembled monolayer) The first polymer is partially cured and the polymer layer (not shown) on the hole pattern mold 150 is separated to form the polymer structure 160. The first polymer may be a material having an etch selectivity with the hole pattern mold 150, for example, polyurethane acrylate (PUA). When the first polymer is provided on the hole pattern mold 150, the first polymer is first filled in the hole 151, and the polymer layer is formed on the upper surface of the hole pattern mold 150. The first polymer provided on the hole pattern mold 150 and the hole 151 is partially cured, and then the polymer layer 160 is rapidly separated to form the polymer pattern 160. The first polymer in contact with the upper surface of the hole pattern mold 150 is removed due to the high aspect ratio of the holes 151 and the wavy serpentine side of the hole 151, The first polymer is left to form the polymer structure 160 and the upper portion of the polymer structure 160 is projected in a hemispherical shape on the upper surface of the hole pattern mold 150.

7A and 7B, the polymer structure 160 is etched to form a polymer structure pattern 165 by etching the upper portion of the polymer structure 160. The polymer structure pattern 165 may have an inverse suction cup shape, and the shape of the inverse suction cup may have a diameter of 500 to 1,500 nm and a height of 50 to 250 nm. The etching process may be, for example, a dry etching process using oxygen plasma. The polymer structure 160 is etched by the etching process while the hole pattern mold 150 is not etched so that the first recess region 151a is formed between the polymer structure pattern 165 and the hole side 151s above the hole 151 166 may be formed. The first recess region 166 may have an annular shape surrounding the polymer structure pattern 165.

8A and 8B, a second polymer is provided on a hole pattern mold 150 on which a polymer structure pattern 165 is formed, cured, and separated to form a preliminary polymer mold 170. The second polymer may be, for example, a polyurethane acrylate. The preliminary polymer mold 170 includes a first protrusion 175 formed by inserting the second polymer into the first recess region 166 of the hole pattern mold 150. The first protrusion 175 protrudes above the upper surface of the preliminary polymer mold 170 and may have an annular cross section in a direction parallel to the upper surface. The diameter Dp of the first protrusion 175 may be 500 to 1,500 nm. A suction cup shaped or crater shaped space 175a which is recessed therein by the first projection 175 can be defined. The height Hp of the space 175a may be 50 to 250 nm. The polymeric structure pattern 165 may be formed on the hole pattern mold 150 before the second polymer is provided on the hole pattern mold 150 so that the preliminary polymer mold 170 can be separated from the hole pattern mold 150. [ The top surface can be surface treated with FOTCS SAM.

Referring to FIGS. 9A and 9B, a third polymer is provided on a preliminary polymer mold 170, cured, and separated to form a polymer mold 180. The third polymer may be, for example, a polyurethane acrylate. The polymer mold 180 includes a second protrusion 185 formed by inserting a third polymer into the space 175a of the preliminary polymer mold 170. A second recess region 186 surrounding the second protrusion 185 may be formed on the upper surface of the polymer mold 180 by the first protrusion 175 of the preliminary polymer mold 170. The second protrusion 185 may have an inverse suction cup shape corresponding to the space 175a, and may have a diameter of 500 to 1,500 nm and a height of 50 to 250 nm. The top surface of the preliminary polymer mold 170 may be surface treated with a FOTCS SAM before the third polymer is provided on the preliminary polymer mold 170 so that the polymer mold 180 can be well separated from the preliminary polymer mold 170. [ have.

Referring to FIGS. 10A and 10B, a fourth polymer is provided on a polymer mold 180, cured, and separated to form a dry adhesion structure 100. The fourth polymer may be, for example, PDMS. The dry adhesive structure 100 includes a bonding portion 120 formed by inserting the fourth polymer into a second recess region 186 of the polymer mold 180. The bonding portion 120 protrudes above the first face 110a of the dry bonding structure 100 and may have a ring-shaped cross-section in a direction parallel to the first face 110a. The diameter Ds of the bonding portion 120 may be 500 to 1,500 nm. The height of the bonding portion 120 from the first surface 110a may be 50-150 nm. A suction cup shaped or crater-shaped adhesive space 120a recessed into the inside thereof by the adhering portion 120 can be defined. The height Hs of the adhesive space 120a may be 50 to 250 nm. The top surface of the polymer mold 180 may be surface treated with a FOTCS SAM prior to providing the fourth polymer on top of the polymer mold 180 so that the dry adhesive structure 100 can be well separated from the polymer mold 180. [

11 and 12 show a method of forming the dry adhesion structure of Fig. The description overlapping with the above-described embodiment may be omitted.

Referring to FIGS. 11 and 12, a fifth polymer, a sixth polymer, and a seventh polymer are successively provided on a polymer mold 180, cured, and separated to form a dry adhesion structure 100. The first body part 111 and the adhesive part 120 may be formed by the fifth polymer. The adhesion portion 120 may be formed by inserting the fifth polymer into the second recess region 186 of the polymer mold 180. The second body portion 112 may be formed by the sixth polymer and the third body portion 113 may be formed by the seventh polymer. The fifth polymer to the seventh polymer may be, for example, PDMS. The fifth polymer, the sixth polymer, and the seventh polymer may include different amounts of a curing agent, whereby the first body part 111, the second body part 112, (113) may have different moduli. For example, the fifth polymer, the sixth polymer, and the seventh polymer may have a weight ratio of PDMS and a curing agent of 5: 1, 10: 1, 20: 1, The modulus of the second body portion 112 and the third body portion 113 may be about 1.6 MPa, about 1.2 MPa, and about 500 kPa, respectively.

13 schematically shows a process of forming a dry adhesion structure according to an embodiment of the present invention.

Referring to FIG. 13, a silicon mold having holes is prepared. The holes may be arranged in two directions intersecting with each other. The diameter and height of the hole are 1 占 퐉 and 3 占 퐉, respectively, and the aspect ratio of the hole is 3. The surface of the silicon mold is treated with a FOTCS SAM and then polyurethane acrylate (PUA) is provided on the silicone mold to partially cure the PUA on the silicon mold. At this time, due to the high aspect ratio of the holes and the wavy serpentine lateral geometry, the PUA contacting the upper surface of the silicon mold is removed and the PUA remains in the hole to form a PUA structure protruding above the silicon upper surface. The PUA structure is subjected to a dry etching process using oxygen plasma to etch an upper portion of the PUA structure to form a PUA structure pattern. The PUA structure pattern has an inverse suction cup shape, and the shape of the inverse suction cup may have a diameter of about 1 mu m and a height of about 150 nm. PUA is provided on the silicon mold having the PUA structure pattern formed thereon, cured, and separated to form a preliminary PUA mold. The top surface of the silicon mold may be surface treated with a FOTCS SAM prior to providing the PUA over the silicon mold so that the preliminary PUA mold can be well separated from the silicon mold. Although not shown in the drawing, the PUA is provided on the preliminary PUA mold, cured, and separated to form a PUA mold. The upper surface of the spare PUA mold may be surface treated with a FOTCS SAM prior to providing the PUA on the spare PUA mold such that the PUA mold can be well separated from the spare PUA mold.

[Electronic patch]

14 is an exploded perspective view of an electronic patch according to an embodiment of the present invention.

14, the electronic patch 10 may include a dry bonding structure 100, an electronic device 200, a first passivation layer 300, and a second passivation layer 400.

The dry adhesive structure 100 can be adhered to the human skin through the adhering portion 120. The structure of the dry adhesive structure 100 for use in the electronic patch 10 is not limited, but it is preferable to use the dry adhesive structure 100 of FIG.

Referring again to FIG. 2, the dry bonding structure 100 may include a body portion 110 and a bonding portion 120. The body portion 110 may include a first body portion 111, a second body portion 112, and a third body portion 113 which are sequentially stacked. The first body part 111 and the adhesive part 120 may be integrally formed.

The first body part 111, the second body part 112, and the third body part 113 may have different modulus. The modulus can be controlled by controlling the amount of the curing agent mixed with the polymer material constituting the first body part 111, the second body part 112, and the third body part 113. [ The modulus may gradually decrease from the first body part 111 to the third body part 113. [ For example, the first body portion 111 may have a modulus of about 1.6 MPa, the second body portion 112 may have a modulus of about 1.2 MPa, and the third body portion 113 may have a modulus of about 500 kPa Of modulus.

The first body portion 111 has a high modulus, thereby facilitating the formation of the bonding portion 120 and enhancing the bonding strength of the bonding portion 120. The third body portion 113 has a low modulus so that the adhesive force of the third body portion 113 with the second protective layer 400 having a low modulus can be improved and the interface between the dry adhesive bonding structure 100 and the second protective layer 400, . ≪ / RTI >

The electronic device 200 may include a strain sensor, a temperature sensor, an electromyogram sensor, an electroencephalogram sensor, a memory device, a transistor, a heater, or the like, and may measure various human vital signs. Biosignal data measured by a temperature sensor, a strain sensor, an electromyogram sensor, an electroencephalogram sensor, or the like can be stored in a memory device and then analyzed. The memory device may include a DRAM, a flash memory, a resistance RAM, a phase change RAM, a ferroelectric RAM, and the like.

The strain sensor may include a silicon nanomembrane pattern and a metal pattern disposed on the silicon nanomembrane pattern. The silicon nanomembrane pattern is doped with boron and may have a thickness of 80 to 100 nm. The metal pattern may be a Cr / Au (7 nm / 70 nm) pattern. The strain sensor may be encapsulated by a first polymer pattern and a second polymer pattern disposed on the lower and upper portions of the strain sensor, respectively. The first polymer pattern and the second polymer pattern may include polyimide, benzocyclobutene, or an epoxy resin. The temperature sensor may include a metal pattern, for example, a Ti / Pt (5 nm / 40 nm) pattern. Since the strain sensor, the temperature sensor, and the interconnection lines are patterned in a serpentine shape, the electronic patch 10 is stuck to human skin such as the wrist and stably operated even when repeatedly exposed to tension and compression can do.

The first protection layer 300 protects and protects the electronic device 200. The first passivation layer 300 may be formed of a material having a relatively low modulus, for example, silicone rubber.

The modulus of the first passivation layer 300 can be controlled by adjusting the amount of the curing agent mixed with the silicone rubber as a constituent material thereof. The modulus of the first protective layer 300 was measured with respect to the weight ratio of the silicone rubber used for forming the first protective layer 300 and the curing agent added to the silicone rubber.

Material
Mixing ratio Silicone rubber
1: 1 Silicone rubber
2: 1 Silicone rubber
3: 1 Modulus (kPa) 55.3 43.5 39.1

Referring to Table 1, when the weight ratios of the silicone rubber and the curing agent were 1: 1, 2: 1, and 3: 1, the modulus of the first protective layer 300 was 55.3 kPa, 43.5 kPa, and 39.1 kPa, respectively. That is, as the amount of the curing agent added decreases, the modulus of the first protective layer 300 decreases.

The second protection layer 400 functions to protect the electronic device 200 while supporting the first protection layer 300. The second protective layer 400 may be formed of a material having a relatively low modulus, for example, PDMS. The second passivation layer 400 is preferably formed of the same material as the dry bonding structure 100 to enhance the adhesive strength with the dry bonding structure 100.

The modulus of the second protective layer 400 may be the same as the modulus of the first protective layer 300 in order to stably cope with tension and compression repeatedly exposed after the electronic patch 10 is adhered to human skin A similar one is desirable. Referring to Tables 1 and 2, when the weight ratio of the silicone rubber and the curing agent is 3: 1 when the first protective layer 300 is formed of silicone rubber, the modulus of the first protective layer 300 is 39.1 kPa And the second protective layer 400 is formed of PDMS, the modulus of the second protective layer 400 is 39.3 kPa, which is similar to the modulus of the first protective layer 300, when the weight ratio of the PDMS and the curing agent is 40: 1. Therefore, it is preferable that the first protective layer 300 is formed by setting the weight ratio of the silicone rubber and the curing agent to 3: 1, and the second protective layer 400 is formed by setting the weight ratio of the PDMS and the curing agent to 40: 1 Do.

The first passivation layer 300, the electronic device 200, the second passivation layer 400 and the dry adhesion structure 100 may have thicknesses of about 14 μm, 1.6 μm, 29 μm and 4 μm, respectively, The electronic patch 10 may have a thickness of 50 mu m or less.

The electronic patch 10 may further include an electrode 510 disposed on the dry adhesive structure 100, a wire 520 for supplying power to the electrode, and a drug carrier 530 disposed on the electrode.

Electrode 510 is exposed to the transdermal delivery rate of drug 532 filled in mesoporous silica nanoparticles 531 of drug delivery system 530 disposed thereon using iontophoresis transdermal delivery rate.

The drug delivery system 530 may include mesoporous silica nanoparticles 531 and a drug 532 filled into the nanopores of mesoporous silica nanoparticles 531. The mesoporous silica nanoparticles 531 function as drug delivery transporters and can prevent the oxidation, denaturation, and unstimulated diffusion of the drug. Nanopores in the mesoporous silica nanoparticles 531 can provide a large surface area for drug adsorption and loading.

In this embodiment, the electronic patch 10 includes the electrode 510 for the electro-osmosis method, and describes the transdermal delivery of the drug 532 of the drug delivery unit 530 using the electro-osmotic method But is not limited thereto. In another embodiment, the electronic patch 10 may include a heater (not shown) and transdermally deliver the drug 532 of the drug delivery device 530 through heating by the heater.

15A to 15H are views for explaining transdermal drug delivery using the electroosmotic method according to an embodiment of the present invention.

15A shows images of mesoporous silica nanoparticles and mesoporous silica nanoparticles filled with doxorubicin drug. Referring to FIG. 15A, nano pores in the mesoporous silica nanoparticles provide a large surface area for drug loading, and doxorubicin drugs are loaded into the nanopores. In addition, the drug can penetrate deeply into the skin due to charge repulsion between the electrode and the drug.

15B is a graph showing the depth of drug diffusion into the skin of experimental rats relative to the number of stimulation in the electroosmotic method. Referring to FIG. 15B, it can be seen that the diffusion depth of doxorubicin drug into the skin of the experimental rat is greatly increased in proportion to the number of applied poles. For example, the diffusion depth of the doxorubicin drug by the electroosmotic method was found to be greater than 200 [mu] m with 12 stimulations. FIG. 15C shows the diffusion depth of doxorubicin drug by three stimulations, and FIG. 15D shows the diffusion depth of doxorubicin drug by 12 stimulations. 15C and 15D, it can be seen that the difference in the diffusion depth due to the difference in the number of the magnetic poles clearly appears.

Figures 15E-15G show images of electrodes that change when reusing the drug. FIG. 15E shows an image of the electrode when doxorubicin (red) was loaded on mesoporous silica nanoparticles, FIG. 15F shows an image when the electrode was washed after use, and FIG. 15G shows an image of 9,10- An image of the electrode is shown when reloading diphenylanthracene (DPA) (green). As described above, the electronic patch and the dry adhesion structure according to the embodiments of the present invention can be easily reused through cleaning after drug use.

Figure 15h shows the experimental rat skin image after delivery of both drugs, doxorubicin and 9,10-diphenylanthracene. The diffusion depth of 9,10-diphenylanthracene was twice the diffusion depth of doxorubicin when the number of stimulating water of 9,10-diphenylanthracene was doubled to that of doxorubicin.

Although not shown in the drawing, an electronic patch having a dry adhesion structure loaded with a drug carrier filled with an anti-inflammatory drug after infecting a laboratory mouse with lipopolysaccharide and bacterial endotoxin as inflammation inducing factors was used for the experiment Histopathological, immunofluorescence, and western blot analyzes were conducted to confirm that the expression of inflammatory factors was significantly inhibited, such as by treatment with histopathological, immunofluorescence, and western blot analysis, .

[Formation method of electronic patch]

16 to 18 show a method of forming an electronic patch according to an embodiment of the present invention.

16, a sacrificial layer 620 and a first passivation layer 300 are sequentially formed on a support substrate 610, and the electronic device 200 is transferred onto the first passivation layer 300. Referring to FIG.

The supporting substrate 610 may be, for example, a glass substrate. For example, the sacrificial layer 620 may be formed of polyvinyl acetate (PVA), and the first passivation layer 300 may be formed of silicon rubber. For example, the first passivation layer 300 may be formed with a weight ratio of silicone rubber and a curing agent of 3: 1, and may have a modulus of about 39 kPa. The first passivation layer 300 may be formed to a thickness of about 14 mu m.

The electronic device 200 may include a strain sensor, a temperature sensor, an electromyogram sensor, an electroencephalogram sensor, a memory device, a transistor, a heater, and the like. The memory device may include a DRAM, a flash memory, a resistance RAM, a phase change RAM, a ferroelectric RAM, and the like.

The strain sensor may be formed in the following manner. A sacrificial layer is formed on the silicon wafer. The sacrificial layer may be formed of PMMA or thermally deposited nickel. A first polymer layer is formed on the sacrificial layer by spin coating. The first polymer layer may be formed of polyimide, benzocyclobutene, or an epoxy resin. To form silicon-on-insulator (SOI) wafers with 80-100 nm thick silicon nanomembranes doped with boron. The silicon nanomembrane is transferred onto the first polymer layer. A metal layer is formed on the silicon nanomembrane using a thermal deposition process. The metal layer may be formed of Cr / Au (7 nm / 70 nm). A second polymer layer is formed on the metal layer by spin coating. The first polymer layer may be formed of polyimide, benzocyclobutene, or an epoxy resin. The first polymer layer, the silicon nanomembrane, the metal layer, and the second polymer layer are patterned in a meandering shape to form a first polymer pattern, a silicon nanomembrane pattern, a metal pattern, and a second polymer pattern. The silicon nanomembrane pattern and the metal pattern function as a strain sensor, and the first polymer pattern and the second polymer pattern may function as an encapsulation layer. After the sacrificial layer is removed with a wet etching solution such as acetone, a strain sensor encapsulated with the first polymer pattern and the second polymer pattern is separated from the silicon wafer and transferred onto the first protective layer 300.

The temperature sensor may be formed of a metal pattern, for example, a Ti / Pt (5 nm / 40 nm) pattern by performing thermal vapor deposition using a serpentine metal mask.

The electronic device 200 may be formed to a thickness of about 1.6 mu m.

17, the upper surface of the polymer mold 180 is surface-treated with a FOTCS SAM, and then the fifth polymer solution, the sixth polymer solution, the seventh polymer solution, and the eighth polymer solution are sequentially spin-coated on the polymer mold 180 Coating and curing. The fifth to eighth polymers are partially cured in a 70 ° C oven. The fifth to eighth polymer solutions may be a PDMS prepolymer solution diluted with an organic solvent, for example, toluene. The concentration of the eighth to eighth polymer solutions may be 0.5 g / mL, 1 g / mL, 2 g / mL, 4 g / mL, and may be mixed with the PDMS curing agent at a concentration of 0.1 g / mL.

The first body part 111 and the adhesive part 120 may be formed by the fifth polymer. The adhesion portion 120 may be formed by inserting the fifth polymer into the second recess region 186 of the polymer mold 180. The second body portion 112 may be formed by the sixth polymer, the third body portion 113 may be formed by the seventh polymer, and the second protective layer 400 May be formed. The dry adhesion structure 100 may be formed to a thickness of about 4 탆 and the second passivation layer 400 may be formed to a thickness of about 29 탆.

Since the fifth polymer, the sixth polymer, the seventh polymer, and the eighth polymer include different amounts of the curing agent, the first body part 111, the second body part 112, The first passivation layer 113, and the second passivation layer 400 may have different moduli. For example, the fifth polymer, the sixth polymer, the seventh polymer, and the eighth polymer may each have a weight ratio of PDMS and a curing agent of 5: 1, 10: 1, 20: 1, 40: 1, The modulus of the first body part 111, the second body part 112, the third body part 113 and the second protective layer 400 are about 1.6 MPa, about 1.2 MPa, about 500 kPa, about 39 kPa Lt; / RTI >

18, the polymer mold 180 is aligned on the support substrate 610 and then the second protective layer 400 is bonded to the first protective layer 300 on which the electronic device 200 is disposed. At this time, the first protective layer 300 and the second protective layer 400 may be uniformly pressed to be stably bonded. Then, the dry adhesive structure 100, the first passivation layer 300, and the second passivation layer 400 are completely cured in a 70 ° C oven.

Although not shown in the drawing, the sacrificial layer 620 is removed to separate the support substrate 610 from the first passivation layer 300, and the polymer mold 200 is separated from the dry adhesion structure 100. An electrode for electrochemical penetration of the drug can be transferred onto the dry adhesive structure 100 using a water-soluble tape, whereby an electronic patch can be formed. The electronic patch 10 may be formed to a thickness of 50 mu m or less.

A drug carrier may be loaded on the electrode. The drug delivery system may include mesoporous silica nanoparticles and drugs filled into the nanopores of the mesoporous silica nanoparticles.

19 schematically shows a process of forming an electronic patch according to an embodiment of the present invention.

19, a PVA layer and a silicone rubber layer are formed on a glass substrate, and the electronic device is transferred onto the silicone rubber layer. In addition, a PUA mold is used to form a PDMS dry adhesion structure and a PDMS protective layer whose modulus gradually changes. The PUA mold is aligned on the glass substrate, and the PDMS protective layer is bonded to the silicone rubber layer. The PVA layer is removed to separate the glass substrate from the silicone rubber layer, and the PUA mold is separated from the PDMS dry adhesion structure. This forms an electronic patch in which a silicone rubber layer, an electronic device, a PDMS protection layer, and a PDMS dry adhesion structure are sequentially stacked. Although not shown in the drawings, an electrode loaded with drug-loaded mesoporous silica nanoparticles filled with the drug can be formed on the PDMS dry adhesion structure for drug administration using electroosmosis.

Fig. 20 is a graph showing the difference in adhesive force between the electronic patches having different adhesive structures with respect to the human skin. Referring to FIG. 20, an electronic patch combined with a dry adhesion structure (mSC) according to embodiments of the present invention is superior to an electronic patch with a conventional adhesive structure (flat, m-pillar) Lt; / RTI > In addition, among the dry adhesion structures according to the embodiments of the present invention, the dry adhesion structure (Gradual mSC) in which the modulus changes can have an adhesive force superior to the dry adhesion structure (1.2 MPa mSC) in which the modulus is constant at 1.2 MPa.

FIG. 21 shows an image in which an electronic patch, to which a dry bonding structure according to an embodiment of the present invention is coupled, and an electronic patch to which a conventional dry bonding structure is bonded, is bonded to the skin mold. Referring to FIG. 21, the electronic patch with the modified dry adhesion structure (Gradual mSC) according to an embodiment of the present invention can be uniformly and stably bonded along the curved surface of the human skin, while the conventional dry adhesion The structure (1.6 MPa m-pillar) is bonded only at the convex portion, and no adhesion occurs at the concave portion.

Figure 22 shows the system modulus of various electronic patches. In Fig. 22, the red dotted line indicates the modulus of the human epidermis. Referring to FIG. 22, the system patch modulus of an electron patch with a modified dry-bond structure (Gradual SC) according to an embodiment of the present invention is about 108 kPa, which is lower than about 150 kPa, which is the modulus of the human epidermis. Therefore, an electronic patch with a dry adhesive structure (Gradual SC) having a modulus changed is adhered to a human's skin such as a wrist, and can be stably operated even when repeatedly exposed to tension and compression.

FIGS. 23A to 23J show results obtained by applying an electronic patch according to an embodiment of the present invention to an experimental mouse.

23A and 23B, in order to quantitatively evaluate the effects of irritation, irritation, and inconvenience when the electronic patch is attached to human skin, electronic patches having various adhesive structures are attached to the back surface of the experimental rat, respectively We installed a video camera to monitor the behavior of the mice and measure the number of scratches scratching the back for 3 hours.

Referring to FIG. 23C, an electron patch with a modulus-changing dry adhesion structure (Gradual mSC) according to an embodiment of the present invention was firmly adhered to the rat skin for 2 days or more, but the conventional dry adhesion structure m -pillar attached electronic patch fell off in two hours due to poor adhesion and weak mechanical coupling to the skin.

Referring to FIG. 23D, the electronic patch adhered with hydrocolloid had a scratch number four times higher than that of the electronic patch with the modulus changeable dry adhesion structure (Gradual mSC). In addition, the electronic patch with the dry adhesive structure (Gradual mSC) in which the modulus changes is hardly different from the number of scratches in the case where the electronic patch is not adhered, so that it is hardly affected by negative influence such as stimulation by attaching the electronic patch Respectively.

Referring to FIG. 23E, an electronic patch adhered with a hydrocolloid causes skin strain and inconvenience because it generates a high load and strain on the skin. This is similar to the result of the FEM simulation shown in FIG. 23F.

Referring to FIG. 23G, it is difficult to reuse the hydrocolloid patch, which is adhered with hydrocolloid, since the adhesive strength is remarkably decreased after use once, but the dry adhesion structure according to the embodiments of the present invention is combined The electronic patch (mSC patch) can maintain the adhesive strength even after 8 reuses.

Referring to Figures 23h and 23i, an electronic patch (mSC patch) coupled with a dry bonding structure according to embodiments of the present invention may be applied to an electronic patch (Hydrocolloid®) adhered with a hydrocolloid that does not damage the bonded skin, patch may cause skin damage or inflammation after use.

24A to 24G are views for explaining measurement of a living body signal using an electronic patch according to an embodiment of the present invention.

Referring to Figure 24A, an electronic patch with a modulus-varying dry bonding structure (Gradual mSC) provides a skin interface platform for continuously and highly sensitive monitoring of physiological and electrophysiological signals as the ultra-thin electronic sensors are concomitantly integrated . Therefore, even if external pressure is not applied, a slight pulse change can be accurately detected. However, m-pillar patches or hydrocolloid patches do not have sufficient sensitivity to detect pulse signals from the radial artery without external applied pressure.

 Referring to FIGS. 24B to 24G, the physiological signals such as dicrotic notch and pulse gradient pulse, blood pressure, electrocardiogram (ECG), activity tremor, respiration, and body temperature can be accurately measured And can monitor homeostasis during daily life.

[Bio-signal monitoring system]

The bio-signal monitoring system according to embodiments of the present invention includes an electronic patch attached to a living body skin to measure a bio-signal and a control unit for controlling the electronic patch.

The control unit includes a bio-signal control unit, a bio-signal transmitting / receiving unit, and a power supply unit. The controller may include a smart band, the bio-signal controller may include a controller, the bio-signal transmitter and receiver may include Bluetooth, and the power supply may include a battery.

The bio-signal controller may determine whether the bio-signal is abnormal, and the bio-signal transmitter / receiver may transmit the bio-signal received from the electronic patch to an external device.

The bio-signal controller may transmit an alarm signal to the external device through the bio-signal transmitter / receiver when an abnormality of the bio-signal is detected.

FIG. 25 schematically shows a configuration of a smart band according to an embodiment of the present invention, and FIG. 27 shows a configuration of a smart card according to an embodiment of the present invention, including real time sensing, wireless data transmission, Figure 3 shows a schematic diagram of the circuit for control.

25 to 27, the bio-signal monitoring system includes an electronic patch attached to human skin to measure a bio-signal and a smart band for controlling the electronic patch. Since the electronic patch has been described in detail in the above embodiments, redundant description will be omitted.

The electronic patch includes a strain sensor, a temperature sensor, and the like, and can measure physiological signals such as pulse, blood pressure, electrocardiogram, behavioral progress, respiration, and body temperature. Since the electronic patch is stably conformationally attached to the human skin through the dry adhesive structure according to the embodiments of the present invention, the physiological signal can be continuously and accurately measured. It is desirable to use a dry bonding structure in which the modulus changes to have a system modulus lower than the modulus of the human skin while stably conformationally bonding the electronic patch to human skin.

The smart band may include a controller, a Bluetooth unit, and a battery.

The controller can control the operation of the electronic patch (an electronic device such as a sensor, an electrode for electrochemical penetration of a drug), the Bluetooth unit, and the battery.

The Bluetooth unit wirelessly connects an electronic device mounted on the dry adhesive structure of the electronic patch with an external device such as a smart phone or a tablet. Biometric signal data measured in the electronic device can be transmitted to the external device via the Bluetooth unit, and an instruction of the external device can also be transmitted to the electronic device through the Bluetooth unit. For example, the resistance change of the strain gage is measured through a resistor-capacitor RC (see FIG. 27). The resistance change controls the discharge time of the capacitor, and the discharge time is sensed by the controller and transmitted wirelessly to an external device via the Bluetooth unit. When a bioinformation signal such as an acute heart failure or a malfunction signal is measured by the sensor in the electronic patch, the controller can transmit an alarm signal to an external device such as a smart phone or a tablet through the Bluetooth. The smartphone or tablet may transmit the alert signal to a hospital, emergency center, and / or rescue center through an application. The controller can control the transdermal delivery of the drug filled in the mesoporous silica nanoparticles by controlling the electroosmotic electrode disposed on the dry adhesion structure of the electron patch under the command of the external device.

The battery may supply power to the smart band and the electronic patch.

The smart band functions as a control unit in the bio-signal monitoring system, and is shown in the form of a band to be worn on the wrist. However, the present invention is not limited thereto and can be realized in a form other than a band.

28A and 28B show application examples of a bio-signal monitoring system according to an embodiment of the present invention.

28A and 28B, the electronic patch can be attached to various parts of the body through a dry adhesive structure having excellent adhesion to human skin, and can be applied to various physiological signals such as pulse, blood pressure, electrocardiogram, Can be accurately measured in real time. The measured physiological signal data can be transmitted to an external device via a smart band and can be managed in real time. The smart band can transmit an alarm signal to an external device when a bio-abnormality signal or a malfunction signal is measured by a sensor included in the electronic patch, and the smart- Lt; RTI ID = 0.0 > of drug < / RTI >

Hereinafter, specific embodiments of the present invention have been 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 disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

10: electronic patch 100: dry adhesive structure
200: electronic device 300: first protective layer
400: second protection layer 510: electrode
530: drug delivery vehicle

Claims (15)

A body portion having a first surface and a second surface facing each other; And
And an adhesive portion disposed on the first surface,
The bonding portion has a ring-shaped cross section in a direction parallel to the first surface,
A suction cup shaped or crater-shaped adhesive space recessed into the inside thereof is defined by the adhering portion,
The height of the adhesive space is larger than the height of the adhesive portion,
The aspect ratio of the adhering portion indicating the ratio of the height of the adhering portion to the diameter of the adhering portion is less than 1,
Wherein the modulus of the body portion decreases from the first surface to the second surface. A body portion having a first surface and a second surface facing each other; And
And an adhesive portion disposed on the first surface,
The bonding portion has a ring-shaped cross section in a direction parallel to the first surface,
A suction cup shaped or crater-shaped adhesive space recessed into the inside thereof is defined by the adhering portion,
The height of the adhesive space is larger than the height of the adhesive portion,
The aspect ratio of the adhering portion indicating the ratio of the height of the adhering portion to the diameter of the adhering portion is less than 1,
Wherein the modulus of the body portion is 1607 kPa or less. 3. The method according to claim 1 or 2,
The diameter of the bonding portion is 500 to 1,500 nm,
The height of the bonding portion is 50 to 150 nm,
The aspect ratio of the bonding portion is 1/30 to 3/10,
Wherein the adhesive space has a height of 50 to 250 nm. 3. The method according to claim 1 or 2,
The body portion
A first body portion connected to the adhesive portion,
And a second body portion disposed below the first body portion,
Wherein the modulus of the second body portion is smaller than the modulus of the first body portion. 3. The method according to claim 1 or 2,
The dry adhesion structure is formed of a polymer,
Wherein the modulus of the dry adhesion structure is controlled by adjusting the content of the polymer and the curing agent of the polymer. 3. The method according to claim 1 or 2,
Wherein the body portion and the adhesive portion are integrally formed. 3. The method according to claim 1 or 2,
Wherein the dry adhesion structure comprises:
Lt; RTI ID = 0.0 > polydimethylsiloxane. ≪ / RTI > A first polymer is provided on a hole pattern mold having a hole and then the first polymer which is in contact with an upper surface of the hole pattern mold is removed to form a polymer structure that is disposed in the hole and protrudes onto the upper surface of the hole pattern mold ;
Forming a polymer structure pattern by etching the polymer structure;
Providing a second polymer on the hole pattern mold having the structure pattern formed thereon, and separating the second polymer to form a preliminary polymer mold;
Forming a polymer mold by providing a third polymer on the pre-polymer mold and then separating the third polymer; And
Providing a fourth polymer on the polymer mold, and separating the fourth polymer. 9. The method of claim 8,
Wherein the first polymer has an etch selectivity with respect to the hole pattern mold. 9. The method of claim 8,
And a recess region is formed between the side surface of the hole and the polymer structure pattern by the etching. 11. The method of claim 10,
Wherein the height of the recessed region is 50 to 150 nm. 9. The method of claim 8,
The aspect ratio of the hole is 3 or more,
Wherein the side of the hole has a wavy shape. 9. The method of claim 8,
Wherein the first to third polymers are polyurethane acrylates,
Wherein the fourth polymer is polydimethylsiloxane. ≪ RTI ID = 0.0 > 11. < / RTI > 9. The method of claim 8,
Providing a fifth polymer on the fourth polymer before separating the fourth polymer from the polymer mold,
Wherein the fourth polymer and the fifth polymer have different moduli. 15. The method of claim 14,
Wherein the modulus is controlled by adjusting a content of a curing agent contained in the fourth polymer and the fifth polymer.

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