KR20210153875A - artificial skin - Google Patents

Abstract

The present invention relates to a new concept of 'self-healing of heterogeneous' and artificial skin which can self-heal the entire individual imitating human skin produced using the same, and more specifically, to artificial skin which self-recovers the physical performance, electrical performance, and tensile deformation recognition performance of all artificial skin formed by chemically combining hydrogel as the dermis and elastomer as the epidermis with the hydrogen bond-based self-healing of heterologous.

Description

artificial skin

The present invention relates to heterogeneous self-healing and artificial skin capable of total self-healing of human skin produced using the same (Hetero-self-healing and its application of making a natural skin-inspired wholly self-healing artificial skin).

The present invention relates to artificial skin capable of self-healing of the entire individual that mimics human skin using a chemical bond of a new concept called 'hetero-self-healing'.

In detail, as shown in the conceptual diagram of FIG. 1, it relates to artificial skin, which can be called e-skin, produced by hydrogen bonding-based heterogeneous self-healing of a hydrogel serving as a dermis and an elastomer serving as an epidermis. The goal is to provide a new concept of artificial skin that can fully self-restore the physical performance, electrical performance, and tensile strain perception performance of the artificial skin formed by chemical bonding.

Human skin is a versatile platform with a variety of functions required to transmit external stimuli such as temperature and pressure, and has the ability to protect internal organs from external stimuli and stress, as well as the ability to self-heal from unexpected damage. It is an organism equipped with

Human skin consists of an epidermis layer that protects external stimuli and a dermis layer that transmits biological signals, and each layer has the ability to repair itself from external damage.

Therefore, there is an urgent need to develop artificial skin capable of performing the same function as actual skin capable of having such a function.

With this concept, the present inventors considered the elastomer as the skin that can play the role of the epidermal layer, and also conducted a study on the self-healing artificial skin that can bind the hydrogel that can play the role of the dermal layer.

However, since the interfacial adhesion between materials having different surface properties, such as elastomer and hydrogel, is often not chemically preferred, it is difficult to assemble these materials to produce an artificial skin capable of overall self-healing. If there is a means to mutually combine the hydrogel and the elastomer or flexible polymer material having self-healing performance, it was thought that the self-healing performance of the entire artificial skin could be maintained, and the present invention was completed.

Korean Patent Registration Publication KR2000568B Korean Patent Registration Publication KR2104033B

In order to achieve the above object, the present invention provides an insulating self-healing elastomer layer that can serve as the epidermal layer of human skin (the elastomer layer may be made of an elastomer or a self-healing flexible material) and hydrogen bonding or Artificial skin is manufactured by stacking a hydrogel layer (or a self-healing hydrogel layer) corresponding to the dermis layer that can be chemically bonded, such as direct bonding, and chemical bonding between the two layers.

If the self-healing elastomer layer has a self-healing characteristic, specifically, if it has a functional group capable of chemical bonding through a secondary bond such as a direct chemical bond or a hydrogen bond with the hydrogel layer, it is not particularly limited. Preferably, self-healing polyurethane elastomers containing disulfide-based units are preferred.

In addition, the hydrogel layer that can serve as the dermis is not limited as long as the hydrogel is a hydrogel having a functional group capable of chemical bonding with the self-healing elastomer layer, but preferably can chemically bond with the self-healing elastomer It is more preferable to use a hydrogel polymer, which is a conductive, self-healing new material having functional groups.

The self-healing elastomer layer of the present invention may be a self-healing polyurethane-based elastomer as an example of the self-healing elastomer layer, and the technology for this has been described in Korean Patent Registration Publication KR2000568B applied by the present applicant. If it is a flexible material having a property, it may include various materials without being limited thereto. However, in consideration of the elasticity or durability of the surface, the self-healing polyurethane having a disulfide unit may be more preferred.

In addition, as an example of the hydrogel constituting the dermis of the artificial skin of the present invention, as a self-healing 'crosslinked IPN-hydrogel', reference may be made to Korean Patent Registration Publication KR2104033B, etc., and the hydrogel is described in the patent. A hydrogel having self-healing properties is more preferred.

In particular, to further improve the self-healing effect in the present invention, the self-healing elastomer layer and the self-healing hydrogel polymer material having different surface properties can heal heterogeneous self-healing by strong hydrogen bonding, so the actual skin of the present invention It has a self-healing ability similar to that of , so it is possible to provide better artificial skin.

Another object of the present invention is to recover the physical properties, electrical properties, and tensile deformation recognition performance by itself after the entire artificial skin manufactured using the self-healing elastomer and hydrogel polymer material is physically damaged.

Through this, the self-healing artificial skin is manufactured by mimicking human skin and chemically combining the hydrogel with the role of the dermis and the elastomer with the role of the epidermis.

The elastomer used in the present invention is used as a concept encompassing not only an elastomer but also an organic material or an inorganic material as long as it is a flexible material. However, chemical bonds including direct bonds with the hydrogel or secondary bonds such as hydrogen bonds or van der Waals bonds If this is possible, there is no particular limitation.

As the flexible material, it is not limited as long as the flexible material has enough flexibility to be used as artificial skin as in the present invention, but if the 'Young's modulus' value is about 1 GPa or less I prefer it more because it is good for showing soft properties like skin.

One aspect of the present invention provides an artificial skin capable of total self-healing produced by chemically combining a self-healing hydrogel and a self-healing elastomer with heterogeneous self-healing.

Artificial skin according to an aspect of the present invention can provide artificial skin capable of self-healing of the entire individual that mimics human skin by using a chemical bond of a new concept called 'Hetero-self-healing'. .

Specifically, when flaws occur, it is possible to provide artificial skin of a new concept capable of self-recovering all physical performance, electrical performance, and tensile strain recognition performance of the artificial skin formed by chemical bonding.

1 is a schematic diagram of the overall self-healing artificial skin concept of the present invention.
2 shows an adhesion test between a hydrogel and various types of elastomers.
3 shows the polymer microstructure through SAXS crystal analysis of Preparation Example 2 and Comparative Preparation Example 1.
4 is an image of the total self-healing test result of the physical properties of the artificial skin of Example 1.
5 is an image of the results of the self-healing test of the electrical properties of the artificial skin of Example 1.
6 shows the tensile strain sensing characteristics self-healing of the artificial skin of Example 1;

Hereinafter, the present invention will be described in more detail. However, the following specific examples or examples are only a reference for describing the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms.

Also, unless defined otherwise, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description herein is for the purpose of effectively describing particular embodiments only and is not intended to limit the invention.

Also, the singular forms used in the specification and appended claims may also be intended to include the plural forms unless the context specifically dictates otherwise.

Also, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Hereinafter, the present invention will be looked at in detail.

The present invention provides a self-healing artificial skin prepared by chemically combining a self-healing hydrogel and a self-healing elastomer with heterogeneous self-healing.

In the present invention, the heterogeneous self-healing provides an artificial skin capable of heterogeneous self-healing by a chemical bond formed at the interface by the dynamic behavior of self-healing materials having different surface properties.

The hydrogel may be a hydrogel including a hydrogel capable of self-healing and having electrical conductivity.

In addition, the elastomer may be an elastomer capable of self-healing and electrically insulating.

In the present invention, total self-healing may mean that the artificial skin has a property of self-recovering physical performance, electrical performance, and tensile strain recognition performance only by physical contact after the artificial skin is physically damaged.

The hydrogel may include a hydrogel having a functional group capable of hydrogen bonding with the elastomer as a component.

In addition, in the present invention, the hydrogel includes an ionic salt, an ionic liquid, a metal particle additive, and the like, and may include a hydrogel having electrical conductivity.

In addition, the hydrogel may include a hydrogel capable of self-healing because it contains a dynamic ionic bond between a metal ion and a polymer functional group.

In addition, in the present invention, the hydrogel is derived from a vinyl-based monomer having an active hydrogen atom-containing group and is a cross-penetrating polymer network comprising a chemically crosslinked double network structure of a vinyl-based polymer and a crystal-crosslinked polyvinyl alcohol-based second polymer. It may include a cross-linked IPN hydrogel having a structure.

The first vinyl-based polymer may be a cross-linked vinyl-based first polymer polymerized including acrylic acid, a metal salt, and a polyfunctional acrylic or acrylamide-based crosslinking agent, and the second polymer may be polyvinyl alcohol, and the polyvinyl alcohol A crosslinked IPN hydrogel may be prepared by repeating freezing and thawing after preparing an IPN hydrogel having a crosslinked network structure by adding the monomer and a crosslinking agent to an aqueous vinyl alcohol polymer solution.

In addition, the hydrogel is a self-healing hydrogel including any one or more dynamic covalent bonds selected from a disulfide bond, an imine bond, an acylhydrazone bond, and a boronate ester bond. may include.

In addition, the hydrogel may include a hydrogel capable of self-healing including a functional group capable of hydrogen bonding at least one selected from a hydroxyl group, an amine group, a carboxyl group, and a thiol group.

In the present invention, the elastomer may be an elastomer (including a flexible shoe material) including a functional group capable of hydrogen bonding with the hydrogel.

In addition, the elastomer may include an elastomer capable of self-healing because it contains a dynamic ionic bond or a dynamic coordination bond between a metal ion and a polymer functional group.

In addition, the elastomer of the present invention is a self-healing elastomer comprising at least one dynamic covalent bond selected from a disulfide bond, an imine bond, an acylhydrazone bond, and a boronate ester bond. may include.

In addition, in the present invention, the elastomer may include an elastomer capable of self-healing because it includes a functional group capable of hydrogen bonding at least one selected from a hydroxyl group, an amine group, a carboxyl group, and a thiol group.

In addition, in the present invention, the elastomer may have a meaning equivalent to an organic or inorganic material having a 'Young's modulus' value of about 1 GPa or less.

The following is an artificial skin of the present invention, which is a self-healing elastomer layer material, which is an aspect of the present invention, as a self-healing elastomer layer material, as an artificial skin of the present invention, and a self-healing hydrogel. A method for manufacturing artificial skin by hydrogen bonding to have a self-healing function will be described.

In the artificial skin of the present invention, first, a self-healing elastomer sheet corresponding to the epidermis is prepared and a hydrogel layer is laminated on the sheet.

During the lamination, the self-healing elastomer and the hydrogel layer are in contact with each other for a predetermined time or at a predetermined temperature so that a chemical bond such as a hydrogen bond or a direct chemical bond is made.

By maintaining this contact time, a direct chemical bond or a secondary bond such as a hydrogen bond or a van der Waals bond is formed, and both layers are firmly bonded to complete an artificial skin that simulates the dermis and the endothelium.

As an example of the above chemical bond, an interlayer chemical bond is formed by hydrogen bonding between the urethane group of the polyurethane elastomer including the disulfide unit and the hydroxyl group of the 'crosslinked IPN-hydrogel'.

In order to form a hydrogen bond, there is no particular limitation between the self-healing urethane-based elastomer and the hydrogel having a hydroxyl group, but preferably, when the interlayer adhesion is maintained at 0 to 60° C. for 10 minutes to 48 hours, the urethane group of the urethane elastomer and the hydrogel A chemical bond is created by hydrogen bonding of the hydroxyl group of the skin, so that the dermis and epidermis of the skin are tightly bonded to complete the artificial skin.

When damage occurs to the finished artificial skin due to an external impact, the damaged area can be automatically healed by the bonding of the damaged area itself of the self-healing urethane elastomer layer and the hydrogen bond between the elastomer layer and the hydrogel layer.

In the present invention, a self-healing polyurethane elastomer containing a disulfide unit prepared in KR2000568B, etc., previously applied by the present applicant as a material having a particularly excellent self-healing effect, may be exemplified. And it can be known about the self-healing effect.

In brief, a self-healing polyurethane-based polymer polymerized from a composition including an aromatic disulfide-based diol containing a compound represented by the following Chemical Formula 1, a branched acyclic aliphatic polyisocyanate, and a polyol may be exemplified.

[Formula 1]

HO-Ar1-S-S-Ar2-OH

(In Formula 1, Ar1 and Ar2 are each independently a substituted or unsubstituted arylene group having 6 to 30 carbon atoms.)

The branched acyclic aliphatic polyisocyanate is not particularly limited, but is preferably propylene-1,2-diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate and 2,4,4-trimethylhexamethylene diisocyanate. It may be any one or a mixture of two or more selected.

In the present invention, the polyol component is not particularly limited, but may be any one or a mixture of two or more selected from ether-based polyols, ester-based polyols and carbonate-based polyols.

The prepared self-healing polyurethane is not particularly limited, but may have more improved self-healing properties when it has the properties of the following Relational Formula 1.

[Relational Expression 1]

0.05 ≤ M[disulfide]/M[OH]

(In Relation 1, M[disulfide] is the total number of moles of aromatic disulfide diols in the composition, and M[OH] is the total number of moles of aromatic disulfide diols and polyols in the composition.)

In addition, the self-healing polyurethane is not limited, but may be, for example, a self-healing polyurethane satisfying the toughness recovery rate of the following relation (2).

[Relational Expression 2]

50 ≤ T1/T0 × 100

(In Relation 2, T0 is the self-healing polyurethane-based polymer pre-cut toughness (MJ/m3), and T1 is the self-healing polyurethane-based polymer toughness (MJ) after cutting and re-bonding at a temperature of 30° C. for 48 hours /m3).

The self-healing polyurethane may be prepared by polymerizing a composition including a disulfide-based diol, branched acyclic aliphatic polyisocyanate, and polyol exemplified by Chemical Formula 1 above.

The self-healing polyurethane (disulfide TPU) of the present invention does not show a crystallinity peak as a result of X-ray observation, which is superior to self-healing properties because it does not show phase separation unlike other polyurethanes that are separated into soft domains and hard domains. I think.

Therefore, the disulfide TPU (Thermoplastic polyurethane) of the present invention hardly occurs phase separation, so no peak is observed in the X-ray scattering results because it maintains an amorphous form as a whole. It is thought to promote interfacial hydrogen bonding through heterogeneous self-healing by causing mutual exchange of hydrogen bonds at the interface with the IPN hydrogel as well as inside the matrix.

The following is a hydrogel, as an example, a method and structure of the cross-linked IPN-hydrogel will be briefly described.

The hydrogel of the present invention is preferably a hydrogel having self-healing properties, for example, a vinyl-based first polymer and crystals derived from a vinyl-based monomer having an active hydrogen atom-containing group and chemically crosslinked with a double network structure. A hydrogel (crosslinked IPN-hydrogel) having a mutually penetrating polymer triple network structure including a crosslinked polyvinyl alcohol-based second polymer may be exemplified.

In addition, the self-healing property is more excellent to also include a unit in the form of a salt by a metal ion in the first polymer, and when a unit containing a metal ion is included, the content of the metal ion is not particularly limited, but active hydrogen It may be preferred to include 0.1 to 10 mol% of the vinyl-based monomer having an atom-containing group.

In the present invention, the hydrogel is not particularly limited, but a self-healing hydrogel having a tensile strength of 50 kPa or more and an elongation of 500% or more is preferred.

The vinyl-based first polymer may be a self-healing hydrogel that is an acrylic polymer, and may have good self-healing power of 70% or more.

The method for preparing the hydrogel is not particularly limited, but for example, a first aqueous solution containing a vinyl-based monomer having an active hydrogen atom-containing group, a crosslinking agent, and water, a polyvinyl alcohol-based polymer, and a preparation containing water 2 preparing a mixed solution by mixing the aqueous solution;

adding an initiator to the mixed solution and polymerization to prepare a hydrogel having a double network structure of chemical crosslinking and interpenetrating polymer; and

Preparing a hydrogel (cross-linked IPN-hydrogel) of a triple network structure of an interpenetrating polymer in which a polyvinyl alcohol-based polymer is crystal-crosslinked by freeze-thawing the hydrogel of the interpenetrating polymer double network structure; can

In addition, by performing chemical crosslinking and metal ion crosslinking at the same time by further including a monomer containing a metal ion in the hydrogel, a more excellent hydrogel can be prepared, and in this case, the content of the metal ion unit monomer contains an active hydrogen atom Containing 0.1 to 10 mol% with respect to the vinyl-based monomer having a group is more preferred because it has more excellent self-healing properties of the present invention.

In the hydrogel of the present invention, the weight ratio of the vinyl-based monomer having the active hydrogen atom-containing group and the polyvinyl alcohol-based second polymer is not limited, but preferably 1: 0.1 to 10 factors may be a self-healing hydrogel.

Although the self-healing mechanism of the present invention is not clear, I think it can be explained by the mechanism shown in FIG. 1 below.

That is, the overall self-healing mechanism of artificial skin composed of cross-linked IPN hydrogel and disulfide TPU is first, the ionic bond formed between the carboxyl group and iron ion of polyacrylic acid inside the IPN hydrogel matrix acts as a dynamic bond, and the IPN hydrogel layer Self-healing can occur at room temperature of And while metathesis of aromatic disulfide and mutual exchange of hydrogen bonds in the disulfide TPU matrix smoothly occur by the amorphous structure, self-healing at room temperature of the disulfide TPU layer may occur.

Hereinafter, the present invention will be described using specific examples for the present invention.

[Preparation Example 1] Preparation of cross-linked IPN-hydrogel (cross-linked ion conductive self-healing interpenetrating polymer network structure hydrogel)

Cross-linked IPN hydrogels were prepared by a two-step cross-linking procedure consisting of free radical polymerization and freeze-thaw cycles by the method described below.

That is, first, as a polyvinyl alcohol solution, polyvinyl alcohol (PVA, 89,000-98,000 g/mol, 99+% hydrolyzed) powder was dissolved in distilled water while vigorously stirring at 90 ° C. ) was prepared.

The following aqueous solution of acrylic acid is acrylic acid (10% by weight compared to distilled water), iron chloride hydrate (FeCl ₃ .6H ₂ O ) (2 mol% compared to acrylic acid) and methylenebisacrylamide (0.1 mol% compared to acrylic acid) in the same amount of water as the PVA. was prepared by mixing.

The polyvinyl alcohol and the aqueous acrylic acid solution were added in a weight ratio of 6:7 and homogeneously mixed, followed by further mixing by stirring for 1 hour. Then, ammonium persulfate (5% by weight relative to acrylic acid) is added to the solution and mixed for 30 minutes, and for free radical polymerization and chemical crosslinking of acrylic acid, the solution vial is completely sealed and polymerized in an oven at 60°C for 12 hours and Crosslinking was performed. For physical crosslinking of polyvinyl alcohol, a glass vial is placed in a freezer at -20 °C for 6 hours, and then stored at 25 °C for 24 hours for thawing to prepare a 'crosslinked IPN-hydrogel' to prepare an artificial dermal material did

[Production Example 2] Insulating self-healing disulfide urethane

20.0 g (20.0 mmol) of polytetrahydrofuran (PTMEG, Mn = 1 kgmol ^-1 ) was put into a glass reactor equipped with a mechanical stirrer, and heated with an oil bath at 100 ° C. under vacuum (<133 Pa) for 1 hour Water was removed by heating.

As a solvent, 9.33 g (42.00 mmol) of isophoronediisocyanate and 0.069 g (2000 ppm) of DBTDL (dibutyltindilaurate) were added dropwise to 10 mL of DMAc (dimethylacetamide) at 70° C., followed by stirring in a nitrogen atmosphere for 2 hours.

After polymerizing the polyurethane prepolymer, the reactor was cooled to 25 °C, 5.01 g (20.00 mmol) of bis(4-hydroxyphenyl)disulfide dissolved in 20 mL of DMAc was added to the reactor, and heated to 40 °C to react for 1.5 hours. to prepare a self-healing polyurethane (TPU).

Then, the TPU solution was heated for 24 hours while slowly raising the temperature from 40 °C to 130 °C, and the residual solvent was removed by vacuum drying at 60 °C for 12 hours. A self-healing TPU (disulfide TPU) having a thickness of 1 mm was prepared and used as the epidermis by heating and pressing the disulfide TPU obtained above at 80° C. and a pressure of 150 bar using a hot press for 5 minutes.

In order to evaluate the crystallinity of the prepared disulfide TPU, small-angle X-ray scattering (SAXS) measurement was performed using synchrotron radiation at a wavelength of 1.28 Å generated by the 3C SAXS I beamline of the Pohang Accelerator Research Institute. The sample-detector distance is set to 1930 mm.

As shown in FIG. 3 , in the X-ray scattering result, the commercial TPU showed ^{a peak at 0.04 nm -1} , whereas the disulfide TPU of the present invention (Preparation Example 2) did not show an observable peak in the entire measurement range. However, it indicates that the commercial TPU of Comparative Preparation Example 1 has a fine phase-separated structure composed of a hard domain and a soft domain. Therefore, the amide bond included in the hard domain is not suitable for interfacial hydrogen bonding with the IPN hydrogel through heterogeneous self-healing. On the other hand, since the disulfide TPU hardly occurs phase separation, and maintains an amorphous form as a whole, no peak was observed in the small-angle X-ray scattering results. It can be seen that the non-localized hard domains increase chain motion, resulting in the mutual exchange of hydrogen bonds inside the TPU matrix as well as at the interface with the IPN hydrogel, thereby promoting interfacial hydrogen bonding through heterologous self-healing. .

[Comparative Preparation Example 1] Insulating non-value-healing commercial urethane

Commercial TPU is purchased from (Dongseong, 5575AP grade, Korea), and the film (thickness = 1 mm) is compressed at 150 ° C. at 150 bar hydraulic pressure for 5 minutes using a hydraulic hot press machine.

[Comparative Preparation Example 2] Insulative non-healing polydimethylsiloxane (PDMS)

The PDMS (Sylgard 184) kit uses a product purchased from Dow Corning (USA), and after mixing the base and curing agent in a ratio of 10: 1, defoaming in a vacuum desiccator for 30 minutes. The mixture is poured into a plastic dish and stored in an oven at 60° C. for 24 hours to fully cure.

[Example 1] Preparation and evaluation of self-healing artificial skin

The cross-linked IPN hydrogel of Preparation 1 and the self-healing TPU of Preparation Example 2 were cut into squares, respectively, superimposed on each other, in physical contact, and left at 25° C. for 12 hours to induce interlayer hydrogen bonding to induce interlayer hydrogen bonding. The skin was prepared.

After leaving the above, as in FIG. 2 , as a result of separating both layers, a lot of residues of IPN-hydrogel remained in the self-healing TPU layer throughout the entire area in the form of a layer, so that the bonding between the two layers was well made. could see that That is, when the cross-linked IPN hydrogel was peeled from the disulfide TPU surface, only the upper layer of the cross-linked IPN hydrogel was separated from the disulfide TPU, and the hydrogel residue remained firmly on the surface, indicating that the cohesive failure of the IPN hydrogel near the interface was indicates what has occurred.

In addition, for the measurement of adhesion, an IPN hydrogel (thickness = 5 mm) was placed between a pair of self-healing TPUs (thickness = 1.5 mm) (distance = 2 mm) at 25 °C for 12 hours (overlapping area: width = 10 mm and length = 5 mm) between the elastomers. Adhesive performance was measured while ^{applying tension (tensile factor = 10 mm min -1} ) in the axial direction for the lap-shear test of adhesion using a universal testing machine (UTM, Instron 5943, UK) equipped with a 1-kN load cell, As a result, as shown in the graph of FIG. 2 and Table 1, it can be seen that the adhesive strength of the present invention and the moving distance to detachment have very excellent adhesion.

In Figure 4, for the self-healing test of mechanical and tensile strain cognitive performance of artificial skin, rectangular IPN hydrogel (length = 12 mm and width = 10 mm) and disulfide TPU (length = 20 mm and width = 15 mm) were used. After lamination, it was cut, and as a result of self-healing at room temperature of 25 °C for 48 hours, mechanical restoration was observed in both layers of IPN hydrogel and disulfide TPU, and the result of maintaining interfacial adhesion was observed.

As shown in Figure 5, for the total self-healing test of the electrical properties of the artificial skin device, an S-shaped IPN hydrogel (thickness = 2 mm and width 5 mm) and disulfide TPU (thickness = 5 mm) were laminated at room temperature for 12 An artificial skin device is manufactured through heterogeneous self-healing based on hydrogen bonding over time. After cutting the middle part of the artificial skin device to create a four-part IPN hydrogel and three channel junctions, the two parts were physically contacted again to connect the fracture surfaces and reconstruct the conductive channel. It was confirmed that it was restored to its original state, and the physical properties were restored after 48 hours.

As shown in FIG. 6 , for the self-healing test of the tensile strain recognition performance of artificial skin, artificial skin devices in the initial state and self-healing state were manufactured. Rectangular IPN hydrogel (thickness = 3 mm, length = 12 mm and width = 10 mm) and disulfide TPU (thickness = 1.5 mm, length = 20 mm, and width = 15 mm) were used to fabricate the artificial skin device in the initial state. An artificial skin device is fabricated through heterogeneous self-healing based on hydrogen bonding for 12 hours at room temperature by stacking. In order to produce artificial skin in a self-healing state, the middle part of the artificial skin device in the initial state was cut, and then self-healing was performed at room temperature for 48 hours to manufacture an artificial skin device in a self-healing state. In order to confirm the change in the electrical resistance of the IPN hydrogel according to the tensile deformation, copper wires were connected to both ends of the IPN hydrogel used in the electronic body in the initial state and self-healing state. The artificial skin device in the initial state and self-healing state was fixed on a tensile tester, respectively, and tensile deformation was applied to disulfide TPU and the change in electric resistance of the IPN hydrogel was measured. As a result, there is little difference in electric resistance change due to tensile deformation. could confirm that

[Comparative Example 1]

As a result of performing the same experiment as in Example 1 using the general polyurethane of Comparative Preparation Example 1, as shown in Table 1 below, the adhesive strength was very low and the detachment movement distance was also very low, so it could not be used as artificial skin.

[Comparative Example 2]

As a result of performing the same experiment as in Example 1 using the siloxane-based resin of Comparative Preparation Example 2, as shown in Table 1 below, the adhesive strength was very low and the detachment movement distance was also very low, so it could not be used as artificial skin.

Comparison of adhesion performance by physical contact between dissimilar materials (hydrogel and soft material) type of soft material Maximum adhesive strength (N) Movement distance to detachment (mm) Example 1 0.78 19.7 Comparative Example 1 0.40 6.4 Comparative Example 2 0.12 2.6

As described above, the present invention has been described with specific details and limited examples and drawings, but these are only provided to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and the present invention is not limited to the above embodiments. Various modifications and variations are possible from these descriptions by those of ordinary skill in the art.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and not only the claims described below, but also all of the claims and all equivalents or equivalent modifications to the claims will be said to belong to the scope of the spirit of the present invention. .

Claims (16)

A self-healing artificial skin made by chemically combining self-healing hydrogel and self-healing elastomer with heterogeneous self-healing. The method of claim 1,
The heterogeneous self-healing is an artificial skin capable of chemical bonding formed at the interface by the dynamic behavior of self-healing materials having different surface properties. The method of claim 1,
The hydrogel is a self-healing artificial skin comprising a hydrogel having electrical conductivity as a component. The method of claim 1,
The elastomer is a self-healing artificial skin comprising an elastomer having electrical insulation as a component. The method of claim 1,
Whole self-healing is the artificial skin that has the property of self-recovering physical performance, electrical performance, and tensile deformation recognition performance only by physical contact after the artificial skin is physically damaged. 4. The method of claim 3,
The hydrogel is an artificial skin comprising a hydrogel having a functional group capable of hydrogen bonding with the elastomer as a component. 4. The method of claim 3,
The hydrogel contains any one or more selected from ionic salts, ionic liquids, and metal particle additives, so that the artificial skin includes a hydrogel having electrical conductivity. 8. The method of claim 7,
The hydrogel contains a dynamic ionic bond between a metal ion and a polymer functional group, and thus an artificial skin comprising a hydrogel capable of self-healing. 4. The method of claim 3,
The hydrogel is derived from a vinyl-based monomer having an active hydrogen atom-containing group and is a cross-linked polymer having an interpenetrating polymer network including a chemically crosslinked double network vinyl-based polymer and a crystal-crosslinked polyvinyl alcohol-based second polymer. Artificial skin containing IPN hydrogel. 4. The method of claim 3,
The hydrogel includes a self-healing hydrogel including any one or more dynamic covalent bonds selected from disulfide bonds, imine bonds, acylhydrazone bonds, and boronate ester bonds. artificial skin. 4. The method of claim 3,
The hydrogel is a hydroxyl group, an amine group, a carboxyl group, artificial skin comprising a hydrogel capable of self-healing containing any one or more hydrogen bonding possible functional groups selected from the group. 5. The method of claim 4,
The elastomer is an artificial skin comprising an elastomer including a functional group capable of hydrogen bonding with the hydrogel as a component. 5. The method of claim 4,
The elastomer contains a dynamic ionic bond or a dynamic coordination bond between a metal ion and a polymer functional group, so that the artificial skin includes an elastomer capable of self-healing. 5. The method of claim 4,
The elastomer is a self-healing elastomer including any one or more dynamic covalent bonds selected from a disulfide bond, an imine bond, an acylhydrazone bond, and a boronate ester bond. artificial skin. 5. The method of claim 4,
The elastomer contains a functional group capable of hydrogen bonding at least one selected from a hydroxyl group, an amine group, a carboxyl group, and a thiol group, so that the artificial skin includes an elastomer capable of self-healing. 5. The method of claim 4,
The elastomer is artificial skin that is selected from organic or inorganic materials having a tensile modulus of elasticity (Young's modulus) of 1 GPa or less.

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