A composite material for bionic skin

Abstract

The present invention discloses a composite material for bionic skin, comprising an adhesive film layer or / and an adhesive film layer and a structural film layer; two adjacent adhesive film layers are adhered; two adjacent structural film layers are adhered through an adhesive film layer; the structural film layer is one or more of a polyurethane film layer, a polycarbonate butanediol ester film layer, and a silicone rubber film layer. The bionic skin made of the composite material of the present invention has elasticity close to that of living skin, and its damage effect is close to that of living skin.

Description

Technical Field

[0001] The present invention relates to the technical field of material bionics. Specifically, it is a composite material for bionic skin. Background Art

[0002] When studying the degree of infringement or damage to the human body caused by high-speed impact, as well as the injury mechanism and damage effect, it is often necessary to use some test materials for testing. These test materials generally choose animal tissues, or polymer materials, or natural materials (such as wood) to act as. However, since the infringement or damage to the human body caused by high-speed impact occurs when a person is alive, there are significant differences in the physical properties of human tissues when they are on a living person and when they are on a corpse. For example, the skin on a living body has good elasticity, while the skin detached from the living body has poor elasticity. If you want to more fully understand the injury mechanism and damage effect when the human body is subjected to high-speed impact, the most ideal way is to conduct experiments on a living body. This experimental method violates ethical and moral principles and does not meet the actual requirements. Therefore, people have begun to use various materials to bionic human skin and other tissues, but still have not obtained a more ideal bionic material. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to provide a composite material for bionic skin. The bionic skin made of this composite material has elasticity close to that of living skin, and its damage effect is close to that of living skin.

[0004] To solve the above technical problems, the present invention provides the following technical solutions:

[0005] A composite material for bionic skin includes an adhesive film layer or / and an adhesive film layer and a structural film layer; two adjacent adhesive film layers are bonded; two adjacent structural film layers are bonded through an adhesive film layer; the structural film layer is one or more of a polyurethane film layer, a polycarbonate butanediol ester film layer, and a silicone rubber film layer.

[0006] For the above composite material for bionic skin, the adhesive film layer is a polyvinyl acetate film layer.

[0007] For the above composite material for bionic skin, the polyvinyl acetate used to prepare the polyvinyl acetate film layer is prepared by an irradiation method.

[0008] For the above composite material for bionic skin, when the bionic skin includes four or more film layers, the adhesive film layer includes a first adhesive layer and a second adhesive layer, and both the first adhesive layer and the second adhesive layer are polyvinyl acetate film layers; from the surface layer to the inner layer of the bionic skin, only the first structural film layer and the second structural film layer are connected through the first adhesive layer.

[0009] For the above composite material for bionic skin, the polyvinyl acetate used to prepare the second adhesive layer is prepared by an irradiation method.

[0010] For the composite material for the bionic skin described above, the thickness of a single adhesive film layer is less than or equal to that of a single structural film layer.

[0011] For the composite material for the bionic skin described above, the thickness of the polyurethane film layer is 5 - 120 μm, the thickness of the polycarbonate butanediol ester film layer is 2 - 120 μm, and the thickness of the silicone rubber film layer is 10 - 300 μm.

[0012] For the composite material for the bionic skin described above, when preparing the structural film layer and the adhesive film layer into the composite material for the bionic skin, place the assembled blank of the composite material for the bionic skin in an incubator and let it stand and press for 60 - 180 min, then the finished product of the composite material for the bionic skin can be obtained; wherein, the temperature of the incubator is 3 - 12 °C, and the pressure applied during standing and pressing is 50 - 120 Pa.

[0013] For the composite material for the bionic skin described above, the standing and pressing is divided into an initial stage, an intermediate stage, and an ending stage; the duration of the initial stage is t1, the duration of the intermediate stage is t2, the duration of the ending stage is t3, and the total duration of the standing and pressing is t, t:t1=(3 - 4):1, t:t2=(2 - 3):1, t:t1=(3 - 4):1; the temperature of the incubator in the initial stage is 10 - 12 °C, the temperature of the incubator in the intermediate stage is 3 - 6 °C, and the temperature of the incubator in the ending stage is 6 - 10 °C.

[0014] For the composite material for the bionic skin described above, the temperature of the incubator in the initial stage is 10 - 12 °C, the temperature of the incubator in the intermediate stage is 3 - 5 °C, and the temperature of the incubator in the ending stage is 8 - 10 °C.

[0015] The technical solution of the present invention has achieved the following beneficial technical effects:

[0016] 1. The present invention provides a composite material for a bionic skin that can be used to bionically imitate the human skin. It can not only simulate the skin in terms of structure, but also be similar to the real skin in terms of physical properties. In the evaluation of damage effects, the evaluation of the damage effect of the bionic skin prepared by the present invention is the same as that of the real skin.

[0017] 2. The present invention uses the method of low-temperature standing and pressing to laminate the adhesive film layer and the structural film layer together. While ensuring the adhesion force between the adhesive film layer and the structural film layer, it can also ensure that the adhesive film layer and the structural film layer do not peel off from each other when subjected to tensile force. At the same time, when the thickness of the bionic skin is similar to that of the real skin, it can show similar or the same damage effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of the bionic skin in Example 1;

[0019] Figure 2 Schematic structural diagram of the bionic skin in Example 2;

[0020] Figure 3 Schematic diagram of the indentation method test;

[0021] Figure 4 Schematic diagram of the principle of pressure-induced color change of the pressure-sensitive color-changing material. Specific implementation manner

[0022] Example 1

[0023] As Figure 1 shown, the composite material for the bionic skin in this example includes an adhesive film layer, and the adhesive film layer is polyvinyl acetate. Among them, the first adhesive film layer 1-1 acts as the stratum corneum, the second adhesive film layer 1-2 acts as the transparent layer, the third adhesive film layer 1-3 acts as the granular layer, the fourth adhesive film layer 1-4 acts as the spinous layer, the fifth adhesive film layer 1-5 acts as the basal layer, and the sixth adhesive film layer 1-6 acts as the dermis layer.

[0024] When making the composite material for the bionic skin from the adhesive film layer, adhesive film layers with thicknesses of 5μm, 3μm, 10μm, 17μm, 4μm, and 80μm are respectively made, and then stacked together from top to bottom to make a blank of the composite material for the bionic skin. Then, the blank of the composite material for the bionic skin is placed between two stainless steel plates and left to stand and press. Then, the two stainless steel plates together with the blank of the composite material for the bionic skin are put into an incubator, left to stand and press for 80 min, the temperature of the incubator is 5°C, and the weight per unit area of the stainless steel plate above the blank of the composite material for the bionic skin is 5 kg. After the static pressure placement is completed, the composite material for the bionic skin can be obtained.

[0025] Example 2

[0026] As Figure 2 shown, the composite material for the bionic skin in this example includes an adhesive film layer and a structural film layer. Among them, the adhesive film layer is a 1μm-thick polyvinyl acetate film layer, and the polyvinyl acetate used for preparing the polyvinyl acetate thin film is prepared by the irradiation method. The structural film layer includes a 2μm-thick poly(butylene carbonate) film layer, a 4μm-thick poly(butylene carbonate) film layer, a 3μm-thick silicone rubber film layer, a 17μm-thick polyurethane film layer, a 5μm-thick poly(butylene carbonate) film layer, and an 80μm-thick polyurethane film layer. The polyvinyl acetate prepared by the irradiation method can make the polymer main chain molecules connect through chemical bonds, and finally form a three-dimensional network structure, which can improve the mechanical strength, toughness (folding resistance), wear resistance, environmental stress cracking resistance, heat distortion temperature, etc. of the material; at the same time, the irradiation initiates an oxidation reaction, adding polar end groups to the matrix polymer, endowing better adhesion between layers, improving the mechanical strength, interlayer adhesion, aging resistance, etc. of the composite layer thin film, and improving the quality of the composite skin equivalent material.Figure 2 Among them, the first structural film layer 2-1 is a poly(butylene carbonate) film layer with a thickness of 2 μm, serving as the stratum corneum; the second structural film layer 2-2 is a poly(butylene carbonate) film layer with a thickness of 4 μm, serving as the transparent layer; the third structural film layer 2-3 is a silicone rubber film layer with a thickness of 3 μm, serving as the granular layer; the fourth structural film layer 2-4 is a polyurethane film layer with a thickness of 17 μm, serving as the spinous layer; the fifth structural film layer 2-5 is a poly(butylene carbonate) film layer with a thickness of 5 μm, serving as the basal layer; the sixth structural film layer 2-6 is a polyurethane film layer with a thickness of 80 μm, serving as the dermis layer; the first adhesive layer 2-7 and the second adhesive layer 2-8 provide the connection force between different film layers.

[0027] The composite material blank for bionic skin is made by stacking in sequence from top to bottom a 2-μm-thick poly(butylene carbonate) film layer, a 1-μm-thick poly(vinyl acetate) film layer, a 4-μm-thick poly(butylene carbonate) film layer, a 1-μm-thick poly(vinyl acetate) film layer, a 3-μm-thick silicone rubber film layer, a 1-μm-thick poly(vinyl acetate) film layer, a 17-μm-thick polyurethane film layer, a 1-μm-thick poly(vinyl acetate) film layer, a 5-μm-thick poly(butylene carbonate) film layer, a 1-μm-thick poly(vinyl acetate) film layer, and an 80-μm-thick polyurethane film layer. Then, the composite material blank for bionic skin is placed between two stainless steel plates and left to stand and press. Then, the two stainless steel plates together with the composite material blank for bionic skin are placed in an incubator, left to stand and press for 140 min, the temperature of the incubator is 8 °C, and the weight per unit area of the stainless steel plate above the composite material blank for bionic skin is 9 kg. After the static pressure placement is completed, the composite material for bionic skin can be obtained.

[0028] Example 3

[0029] The composite material for bionic skin in this example includes an adhesive film layer and a structural film layer. The bionic skin made of the composite material for bionic skin in this example has the same structure as the bionic skin made in Example 2. Among them, the adhesive film layer includes a first adhesive layer and a second adhesive layer, and both the first adhesive layer and the second adhesive layer are poly(vinyl acetate) film layers; the preparation method of the poly(vinyl acetate) used to prepare the first adhesive layer is: in the presence of acetic acid, using benzoyl peroxide as an initiator, vinyl acetate undergoes bulk polymerization; the poly(vinyl acetate) used to prepare the second adhesive layer is prepared by irradiation method; from the surface layer to the inner layer of the bionic skin, only the first structural layer and the second structural layer are connected through the first adhesive layer. The thicknesses of the first adhesive layer and the second adhesive layer are the same as the thickness of the adhesive film layer in Example 2, and the structural film layer in this example is the same as the structural film layer in Example 2.

[0030] When preparing the bionic skin using the adhesive film layer and the structural film layer in this embodiment, the adhesive film layer between the 2-μm-thick poly(butylene carbonate) film layer and the 4-μm-thick poly(butylene carbonate) film layer is the first adhesive layer, and the remaining adhesive film layers are all the second adhesive layers.

[0031] When preparing the bionic skin in this embodiment, the temperature of the incubator is 12 °C, and the weight per unit area of the stainless steel plate located above the composite blank for bionic skin is 12 kg.

[0032] Example 4

[0033] The composite material for bionic skin in this embodiment has the same composition as the composite material for bionic skin in Example 3, and there are the following differences in the preparation methods:

[0034] Put the two stainless steel plates together with the composite blank for bionic skin into the incubator, keep warm for 50 min at the initial stage, the temperature for heat preservation is 11 °C, after the heat preservation ends, cool down to 4 °C and continue the intermediate-stage heat preservation, the duration of heat preservation is 80 min, and after the intermediate-stage heat preservation ends, heat up to 9 °C and continue to keep warm for 50 min.

[0035] Compare the composite materials for bionic skin in Example 1, Example 2, Example 3 and Example 4 with the back skin of Landrace pigs, and conduct tensile tests and indentation experiments respectively. Among them, the indentation experiment is used to characterize the elasticity. Because the stress-strain relationship is single-valued corresponding in each branch of the specified cycle, the specimen material can be regarded as a certain elastic material during the loading process, and as another elastic material during the unloading process. In this way, it can be tested and processed by means of the method of elastic theory. The principle of elasticity mechanics is to load and press into the surface of the specimen with a specified load, as Figure 3 shown, after the specified holding time, unload, measure the indentation diameter on the surface of the specimen within the specified time, and evaluate the elastic properties of the equivalent material with the average pressure on the indentation surface area of the specimen, so as to achieve the equivalence with the skin.

[0036] Table 1 Tensile test results of the composite materials for bionic skin in Examples 1-4 and pig skin

[0037] Selected Materials Breaking Strength (N) Elongation at Break (%) Example 1 1914.2 44.3 Example 2 2156.1 48.9 Example 3 2113.5 47.2 Example 4 2178.6 49.5 Pig Skin 2017.9 46.1

[0038] When comparing the bionic skin prepared in Example 4 with fresh pig skin, it is found that the consistency of the test results between the bionic skin prepared in Example 4 and fresh pig skin differs by no more than 5%.

[0039] Piezochromic materials are a class of intelligent materials whose colors change significantly under external forces. The color change principle of piezochromic materials is as Figure 4As shown. Piezochromic materials have important potential application prospects in the fields of stress sensing, information storage, anti-counterfeiting of commodities, and light-emitting devices, and have received great attention from people in recent years. In order to conduct accurate blunt impact damage assessment, it is proposed to design to coat the piezochromic material on the surface of the skin equivalent material or blend it with the skin equivalent material. The piezochromic process under different pressure conditions can be quantitatively characterized. As the external force increases, the material undergoes a color change. By regulating the structure and dosage of the piezochromic material, the quantitative relationship between the impact strength and the color is used to equivalently represent the skin damage state under different impact strengths, improving visibility and assessment accuracy. When indentation tests were carried out on the composite materials for bionic skin in Example 1, Example 2, Example 3, and Example 4, as well as the back skin of Landrace pigs and fresh pig skin, there was no difference in the color change of the six materials under sunlight.

[0040] Obviously, the above examples are merely illustrations given for clear explanation and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the claims of this patent application.

Claims

1. A composite material for bionic skin, characterized in that, It includes an adhesive film layer and a structural film layer; two adjacent structural film layers are bonded by the adhesive film layer; the structural film layer is one or more of a polyurethane film layer, a polycarbonate butanediol ester film layer, and a silicone rubber film layer; when preparing the composite material for bionic skin with the structural film layer and the adhesive film layer, the assembled blank of the composite material for bionic skin is placed in an incubator and left to stand and press for 60 - 180 min to obtain the finished composite material for bionic skin; among them, the temperature of the incubator is 3 - 12 °C, and the pressure applied during standing and pressing is 50 - 120 Pa; the standing and pressing is divided into an initial stage, an intermediate stage, and an end stage; the duration of the initial stage is t1, the duration of the intermediate stage is t2, the duration of the end stage is t3, and the total duration of standing and pressing is t, t:t1=(3 - 4):1, t:t2=(2 - 3):1, t:t3=(3 - 4):1; the temperature of the incubator in the initial stage is 10 - 12 °C, the temperature of the incubator in the intermediate stage is 3 - 6 °C, and the temperature of the incubator in the end stage is 6 - 10 °C.

2. The composite material for bionic skin according to claim 1, wherein The adhesive film layer is a polyvinyl acetate film layer.

3. The composite material for bionic skin according to claim 2, characterized in that The polyvinyl acetate used to prepare the polyvinyl acetate film layer is prepared by the irradiation method.

4. The composite material for bionic skin according to claim 1, characterized in that, When the bionic skin includes four or more film layers, the adhesive film layer includes a first adhesive layer and a second adhesive layer, and both the first adhesive layer and the second adhesive layer are polyvinyl acetate film layers; from the surface layer to the inner layer of the bionic skin, only the first structural film layer and the second structural film layer are connected by the first adhesive layer.

5. The composite material for bionic skin according to claim 4, characterized in that The polyvinyl acetate used to prepare the second adhesive layer is prepared by the irradiation method.

6. The composite material for bionic skin according to claim 1, characterized in that, The thickness of a single adhesive film layer is less than or equal to that of a single structural film layer.

7. The composite material for bionic skin according to claim 1, wherein The thickness of the polyurethane film layer is 5 - 120 μm, the thickness of the polycarbonate butanediol ester film layer is 2 - 120 μm, and the thickness of the silicone rubber film layer is 10 - 300 μm.

8. The composite material for bionic skin according to claim 1, wherein The temperature of the incubator in the initial stage is 10 - 12 °C, the temperature of the incubator in the intermediate stage is 3 - 5 °C, and the temperature of the incubator in the end stage is 8 - 10 °C.

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