Gelatin-based elastomer gum, conductive gelatin elastomer material, and methods of making the same

Abstract

The application discloses a gelatin-based elastomer raw rubber, a conductive gelatin elastomer material and a preparation method thereof, relates to the field of biological materials, and the elastomer raw rubber is obtained by melting raw materials including the following components: gelatin, a plasticizer and solution A; the components are as follows in terms of weight fractions: 20-200 weight fractions of the gelatin; 100 weight fractions of the plasticizer; and 10-30 weight fractions of the solution A. The raw material gelatin and the plasticizer have the characteristics of biodegradability, renewability and non-toxicity. The prepared elastomer material uses glycerol and other plasticizers to replace the water component in the hydrogel, thereby improving the mechanical properties and avoiding the shortcoming of dehydration and dryness of the hydrogel. The elastomer material has antibacterial properties, and the antibacterial solution also plays a synergistic role with the conductive substance, further improving the conductivity and mechanical properties of the conductive elastomer material, and the elastomer material has important significance for applications such as long-term use of electrodes, sensors and other applications for detecting and / or monitoring electrophysiological signals.

Description

Technical Field

[0001] This invention relates to the field of biomaterials, and more specifically, to gelatin-based elastomer raw rubber, conductive gelatin elastomer materials, and their preparation methods. Background Technology

[0002] Most human movements are driven by low-potential signals (called electrophysiological (EP) signals), including electrocardiograms (ECG), electrooculograms (EOG), electromyograms (EMG), and electroencephalograms (EEG). EP signals possess rich information extraction capabilities, attracting significant research interest and finding wide application in medical monitoring and human-computer interaction.

[0003] Electrodes are a crucial component in capturing and analyzing electroencephalogram (EEG) signals. EEG signal acquisition electrodes are sensors that transmit bioelectrical signals generated by the brain to the device, converting them into recognizable electrical signals. Designing suitable electrode materials for EEG signal acquisition and ensuring the accuracy of the acquired EEG signals are prerequisites for achieving good performance in brain-computer interfaces. Currently, the most commonly used EEG acquisition product is the Ag / AgCl electrode sensor with a moist conductive gel. Moist EEG sensors can overcome interference caused by hair and obtain accurate brain electrical signals even with subtle movements, making them widely used in clinical and research work. Although moist electrodes are stable, reliable, and have low impedance, traditional Ag / AgCl electrodes have many limitations. For example, the gel used to reduce contact impedance in commercial electrodes may cause skin irritation after long-term measurements. Furthermore, because Ag / AgCl electrodes lose contact with the skin, their rigidity hinders the collection of high-quality signals during movement, and moist electrodes using conductive gel also face problems such as inconvenience in use, difficulty in quick cleaning, and instability in long-term signal acquisition as the conductive gel dries. Therefore, making EEG acquisition electrodes more reliable and convenient, and overcoming hair interference to obtain high-quality signals, are challenges in the development of EEG signal acquisition materials.

[0004] With the rise of flexible electronics technology in recent years, flexible electrodes have received considerable attention. Through continuous optimization, flexible electrodes have become a promising alternative to Ag / AgCl electrodes. Specifically, flexible electrodes have achieved an exceptional stretchability of over 400%, sufficient to ensure high-fidelity measurements during periods of high human motion. Flexible electrodes offer a compliant and comfortable skin interface, reducing measurement impedance and improving the signal-to-noise ratio (SNR). The elimination of electrode gel also enhances wearing comfort and reduces the risk of skin irritation. By integrating with power and wireless communication modules to form independent systems, emerging flexible electrodes have demonstrated superior functionality in personalized healthcare and mobile and wearable applications of human-machine interfaces.

[0005] Gelatin is obtained from the thermal decomposition of animal bones and skin. It is a breakdown product of collagen, widely available and inexpensive, and is a typical renewable and biodegradable biomaterial. Its degradation products are easily absorbed and do not cause inflammatory reactions. Compared with other artificial hydrogels, it has superior biocompatibility and is widely used in cell culture, soft tissue adhesives, and transplantation.

[0006] Furthermore, gelatin elastomers possess a similar Young's modulus to human tissue, which facilitates excellent biomechanical matching at the electron-tissue interface. Their mechanical properties are also highly tunable, enabling gelatin elastomer devices to meet diverse mechanical stiffness requirements in practical applications. Importantly, gelatin elastomers exhibit excellent robustness, allowing them to recover their original shape after compression. Additionally, gelatin elastomers possess good transparency, making them ideal for developing fully transparent bioelectronics. These facts demonstrate that conductive elastomers combine the advantages of three-dimensional hydrogel networks with the excellent electrical conductivity of conductive materials, offering superior mechanical properties compared to conductive hydrogels. They also avoid the drawbacks of material dehydration and drying during prolonged use, and possess characteristics such as flexibility, ductility, lightweight, and biocompatibility. They exhibit high sensitivity, high signal-to-noise ratio, and high cyclic stability when measuring potential signals. Conductive elastomers hold broad application prospects in wearable electronic devices such as electronic skin, flexible electrodes, and flexible sensors. However, wearable pressure sensors based on gelatin elastomers have been rarely reported to date, yet they represent one of the most important development directions for bioelastomers in the future of biomedicine. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a gelatin-based elastomer raw rubber, a conductive gelatin elastomer material, and a method for preparing the same. The elastomer material of this invention features in-situ curing, excellent mechanical properties, injectability, writability, self-adhesion, fracture healing, and biosafety. The electroactive substance used in this invention possesses biocompatibility, good electrical and thermal conductivity, and is biodegradable. In addition to its antibacterial properties, the prepared elastomer material also exhibits a synergistic effect between the antibacterial solution A and the electroactive substance, further enhancing the conductivity and mechanical properties of the elastomer material. This is of significant importance for long-term applications such as electrodes and sensors used for detecting and / or monitoring electrophysiological signals.

[0008] One object of the present invention is to provide a gelatin-based elastomer raw rubber, which is obtained by melting raw materials comprising the following components:

[0009] Gelatin, plasticizer, and solution A;

[0010] Each component, by weight:

[0011] Gelatin 20-200 parts by weight;

[0012] 100 parts by weight of plasticizer;

[0013] Solution A: 10-30 parts by weight.

[0014] Preferably, the components are expressed in parts by weight as follows:

[0015] 30-150 parts by weight of gelatin;

[0016] 100 parts by weight of plasticizer;

[0017] Solution A: 15-20 parts by weight.

[0018] The glass transition temperature of the elastomer raw rubber is -90℃ to 65℃, and the gelation transition temperature is 20℃ to 50℃.

[0019] Preferably, the plasticizer is at least one of glycerin and syrup; and / or,

[0020] Solution A is at least one of citric acid solution, acetic acid solution, and boric acid solution.

[0021] A second objective of this invention is to provide a method for preparing gelatin-based elastomer raw rubber, the method comprising:

[0022] The components are melted in the stated weight proportions to obtain the elastomer raw rubber.

[0023] Preferably, the melting temperature is 55-95℃ and the reaction time is 2-10 days.

[0024] The specific plan is as follows:

[0025] Gelatin and plasticizer are added to a reactor, followed by solution A. The mixture is melted at 55-95°C and reacted for 2-10 days to obtain the raw elastomer.

[0026] A third objective of this invention is to provide a conductive gelatin elastomer material using gelatin-based elastomer raw rubber, wherein the elastomer material is obtained by blending raw materials comprising the following components:

[0027] Elastomer raw rubber, electroactive substances, and solution B;

[0028] Each component, by weight:

[0029] 100 parts by weight of elastomer raw rubber;

[0030] 1-50 parts by weight of the electroactive substance, preferably 5-40 parts by weight;

[0031] Solution B is 10-50 parts by weight, preferably 20-30 parts by weight.

[0032] Preferably, the glass transition temperature of the elastomer material is -90℃ to 45℃, the gelation transition temperature is 30℃ to 60℃, and the conductivity is 33.61 × 10⁻⁶. -4 ~310.21×10 -4 S / m, tensile strength is 133-700KPa.

[0033] Preferably, the electroactive material is at least one of conductive polymer, conductive filler, graphene oxide, reduced graphene oxide, and metal carbonitride;

[0034] The conductive polymer may be a commonly used conductive polymer in the art, such as PEDOT:PSS, polypyrrole, polypyridine, polythiophene, etc.

[0035] The conductive filler can be a commonly used conductive filler in the art, such as carbon nanotubes, metal nanoparticles, metal nanowires, metal nanomesh, amorphous metals, etc.

[0036] The metal carbonitride may be a commonly used metal carbonitride in the art, such as Mxene, etc.; and / or,

[0037] Solution B is at least one of sodium chloride solution, potassium chloride solution, sodium sulfate solution, and lithium bromide solution.

[0038] This invention provides a self-healing gelatin elastomer material with electroactive and antibacterial properties, obtained by compounding the aforementioned elastomer raw rubber with an electroactive substance and solution B. By adjusting the content and type of the electroactive substance, a synergistic effect can be achieved with solution A. Furthermore, by introducing the synergistic toughening of anions and cations in solution B, and a dual conductive network of ionic conductivity and electroactive substance conductivity, the conductivity, mechanical properties, functions, bioactivity, and application areas of the conductive elastomer composite material can be adjusted, thereby obtaining conductive elastomer materials with different tensile strengths, conductivity, and adhesion. Combined with the thermal conductivity of the electroactive substance, the prepared elastomer material exhibits fracture-healing properties, and the mechanical properties remain unaffected after healing. In practical applications, the electroactive substance can be selectively compounded with the elastomer raw rubber according to different application perspectives.

[0039] The fourth objective of this invention is to provide a method for preparing a conductive gelatin elastomer material, the method comprising one of the following four methods:

[0040] The components are mixed and cast according to the stated weight proportions to obtain the elastomer material;

[0041] The elastomer material is obtained by mixing the components in the specified weight proportions and then curing them in situ.

[0042] The components are mixed according to the stated weight proportions and then 3D printed to obtain the elastomer material.

[0043] The electroactive material is obtained by printing an electroactive substance between two layers of elastomer raw rubber to form a sandwich structure.

[0044] The specific casting process can be implemented using the following methods:

[0045] The elastomer raw rubber, electroactive material, and solution B are mixed in a Hacker mixer for 10-40 minutes at a temperature of 45-60°C and a rotation speed of 50-70 r / min. Then, the mixture is pressed into tablets on a vacuum tablet press at a temperature of 40-60°C for 5-30 minutes and a vacuum degree of -0.1 MPa to obtain the elastomer material.

[0046] The in-situ curing can be achieved using the following specific method:

[0047] Electroactive substances are added to solution B and dispersed thoroughly by ultrasonic stirring. The mixture is then mixed with elastomer raw rubber at 60°C, poured into a polytetrafluoroethylene mold, and cured to obtain the elastomer material.

[0048] The 3D printing can specifically adopt the following solution:

[0049] The printing shape is a grid or spider web. After adding the raw material, the temperature of the material barrel and the needle is set to 60-90℃, the material barrel heating time is 10-30min, the extrusion air pressure is 2-8kPa, the high voltage power supply is 3-8kV, the printing speed is 1000-2000mm / min, and the printing spacing is 0.1-20mm.

[0050] Preferably, the 3D printing is coaxial 3D printing.

[0051] The coaxial 3D printing can specifically adopt the following solution:

[0052] The printed shape is a grid or spider web pattern. The material barrel 1 containing the electroactive material is kept at room temperature. The extrusion pressure of material barrel 1 is 0.02-4 kPa. The temperature of material barrel 2 containing elastomer raw rubber and solution B and the needle is set at 60-90℃ and heated for 10-30 minutes. The extrusion pressure of material barrel 2 is 2-8 kPa. The high voltage power supply is 3-8 kV. The printing speed is 1000-2000 mm / min and the printing spacing is 0.1-20 mm.

[0053] The main raw materials used in this invention, gelatin and plasticizers, are biodegradable, renewable, and non-toxic. The electroactive substances are biocompatible, have good electrical and thermal conductivity, and are biodegradable. The prepared elastomer material possesses antibacterial properties, and solution A, which also has antibacterial activity, synergistically enhances the conductivity and mechanical properties of the elastomer material with the conductive substances. Furthermore, the addition of solution B, as a salt solution, not only provides synergistic toughening of anions and cations but also increases the ionic conductivity network. This invention uses plasticizers such as glycerol to replace the water component in the hydrogel, which not only improves mechanical properties but also reduces the drawbacks of hydrogel dehydration and drying. This is of great significance for long-term applications such as electrodes and sensors used for detecting and / or monitoring electrophysiological signals.

[0054] Furthermore, in the preparation method of this invention, raw rubber is obtained by mixing gelatin and a biosafe plasticizer, and then synergistically reinforced using electroactive substances and an acidic solution. No catalysts or organic solvents are introduced during the entire preparation process, making it safe, effective, non-toxic, biodegradable, and possessing excellent environmental, electrical, and antibacterial properties. In addition, the thermal conductivity of the electroactive substances enables the elastomer material of this invention to possess fracture-healing properties, and the mechanical properties remain unaffected after healing. This is of great significance in today's health-conscious world, and the preparation cost is relatively low compared to other biomedical materials. Attached Figure Description

[0055] Figure 1 SEM image of the elastomer film prepared in Example 3;

[0056] As can be seen in the figure, all components within the elastomer membrane are uniformly mixed, and there is no phase separation.

[0057] Figure 2 SEM image of the elastomer film prepared in Example 4;

[0058] The image shows that the carbon nanotubes within the elastomer membrane are uniformly dispersed, which helps to form conductive pathways.

[0059] Figure 3 SEM image of the elastomer film prepared in Example 5;

[0060] The image shows that the silver nanowires within the elastomer membrane are uniformly dispersed, which helps to form conductive pathways. Detailed Implementation

[0061] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0062] All raw materials used in the embodiments of this invention are commercially available products, and specific information is shown in Table 1 below:

[0063] Table 1

[0064] raw material Specification factory gelatin Medical grade Rossello, France glycerin Medical grade Aladdin, USA carbon nanotubes IMC6 Boyu High-Tech, Beijing Silver nanowires XFJ95 Xianfeng Nanomaterials, Jiangsu Sodium chloride ≥99.5% (AT) Aladdin, USA Potassium chloride ≥99.5% (AT) Aladdin, USA Potassium bromide ≥99.5% (AT) Aladdin, USA Citric acid solution ≥99.5% (AR) Aladdin, USA Acetic acid solution ≥99.5% (AR) McLean, China boric acid solution ≥99.5% (AR) McLean, China PEDOT:PSS 250G Sigma, USA Liquid metal GaIn alloy 5G Sigma, USA

[0065] Example 1

[0066] Add 20g of gelatin, 40g of glycerol and 4g of citric acid solution to a reaction flask, stir and place in a vacuum oven at 65℃. After reacting for 3 days, remove the flask to obtain the desired uniform elastomer raw rubber.

[0067] Take 10g of the above elastomer raw rubber and place it in a polytetrafluoroethylene mold. Place it on a vacuum tablet press and press it into a sheet. Set the temperature to 50℃ and the pressing time to 25min to obtain an elastomer film with a thickness of 1mm.

[0068] Example 2

[0069] Add 40g of gelatin, 20g of glycerol and 6g of acetic acid solution to a reaction flask, stir and place in a vacuum oven at 65℃. After reacting for 3 days, remove the flask to obtain the desired uniform elastomer raw rubber.

[0070] Take 10g of the above elastomer raw rubber and place it in a polytetrafluoroethylene mold. Place it on a vacuum tablet press and press it into a sheet. Set the temperature to 45℃ and the pressing time to 25min to obtain an elastomer film with a thickness of 1mm.

[0071] Example 3

[0072] Add 22.5g of gelatin, 22.5g of glycerin, and 4.5g of boric acid solution to a reaction flask, stir, and then place it in a vacuum oven at 60℃. After reacting for 3 days, remove the flask to obtain the desired uniform elastomer raw rubber.

[0073] Take 10g of the above elastomer raw rubber and place it in a polytetrafluoroethylene mold. Place it on a vacuum tablet press and press it into a sheet. Set the temperature to 45℃ and the pressing time to 25min to obtain an elastomer film with a thickness of 1mm.

[0074] Example 4

[0075] Add 10g of gelatin, 50g of glycerol and 5g of acetic acid aqueous solution to a reaction flask, stir and place in a vacuum oven at 60℃. After reacting for 3 days, take it out to obtain the desired uniform elastomer raw rubber.

[0076] 50g and 25g of the above-mentioned elastomer raw rubber were added to 5g of sodium chloride solution and ultrasonically dispersed carbon nanotubes. The mixture was then mixed on a Hacker mixer for 20 minutes at a temperature of 45℃ and a rotation speed of 60 rpm. Then, 10g of the mixture was placed in a polytetrafluoroethylene mold and pressed into a sheet on a vacuum tablet press at a temperature of 45℃ for 20 minutes to obtain an elastomer film with a thickness of 1mm.

[0077] Example 5

[0078] Add 40g of gelatin, 20g of glycerol and 6g of boric acid solution to a reaction flask, stir and place in a vacuum oven at 60℃. After reacting for 3 days, remove the flask to obtain the desired uniform elastomer raw rubber.

[0079] 50g and 25g of the above-mentioned elastomer raw rubber were added to 25g of potassium chloride solution. The ultrasonically dispersed silver nanowires were then mixed on a Hacker mixer for 20 minutes at a temperature of 45℃ and a rotation speed of 60 rpm. Then, 10g of the mixture was placed in a polytetrafluoroethylene mold and pressed into a sheet on a vacuum tablet press at a temperature of 45℃ for 20 minutes to obtain an elastomer film with a thickness of 1mm.

[0080] Example 6

[0081] Add 29.85g of gelatin, 29.85g of glycerol and 5g of citric acid solution to a reaction flask, stir and place in a vacuum oven at 60℃. After reacting for 3 days, remove the flask to obtain the desired uniform elastomer raw rubber.

[0082] 50g and 12.5g of the above-mentioned elastomer raw rubber were added to 15g of lithium bromide solution. The ultrasonically dispersed silver nanowires were then mixed on a Hacker mixer for 20 minutes at a temperature of 45℃ and a rotation speed of 60 rpm. Then, 10g of the mixture was placed in a polytetrafluoroethylene mold and pressed into a sheet on a vacuum tablet press at a temperature of 45℃ for 20 minutes to obtain an elastomer film with a thickness of 1mm.

[0083] Example 7

[0084] Add 29.7g of gelatin, 29.7g of glycerol and 5g of citric acid solution to a reaction flask, stir and place in a vacuum oven at 60℃. After reacting for 3 days, remove the flask to obtain the desired uniform elastomer raw rubber.

[0085] Mix 50g of the above-mentioned elastomer raw rubber, 13g of liquid metal GaIn alloy, and 5g of sodium chloride solution for 20 minutes at a temperature of 70℃ and a rotation speed of 100r / min. Then, wrap a square glass sheet with tin foil and place it on the collection floor. Turn on the BP6601 3D printer, adjust the XYZ axes back to their origins, check the equipment connections, adjust the Z-axis height Z-offset value, and set the spinning gap to 2mm. Remove the material hopper, add 20g of the above mixture, and set the hopper and needle temperature to 80℃. After the hopper has heated for 15 minutes, adjust the extrusion pressure to 4.0kPa, set the high-voltage power supply to 3.7kV, and the printing speed to 1500mm / min. Adjust the model parameters in the software and check the printing path. After confirming that everything is correct, start printing to obtain an elastomer film with a thickness of 2mm.

[0086] Example 8

[0087] Add 29.7g of gelatin, 29.7g of glycerol and 5g of citric acid solution to a reaction flask, stir and place in a vacuum oven at 60℃. After reacting for 3 days, remove the flask to obtain the desired uniform elastomer raw rubber.

[0088] 50g of the above-mentioned elastomer raw rubber was mixed with 25g of sodium chloride solution in a Hacker mixer for 20 minutes at a temperature of 45℃ and a rotation speed of 60 rpm. Then, 10g was placed in a polytetrafluoroethylene mold and pressed into a sheet using a vacuum tablet press at a temperature of 45℃ for 20 minutes to obtain an elastomer film with a thickness of 1mm. Then, 13g of liquid metal was printed onto the surface of the film using a circuit printing template, and then a layer of elastomer raw rubber was covered on top. After in-situ curing, an elastomer film was formed.

[0089] Comparative Example 1

[0090] Add 10g of gelatin and 50g of glycerin to a reaction flask, stir, and place in a vacuum oven at 60℃. After reacting for 3 days, remove the flask to obtain the desired uniform elastomer raw rubber.

[0091] Take 10g of the above elastomer raw rubber and place it in a polytetrafluoroethylene mold. Place it on a vacuum tablet press and press it into a sheet. Set the temperature to 50℃ and the pressing time to 25min to obtain an elastomer film with a thickness of 1mm.

[0092] Comparative Example 2

[0093] Add 29.85g of gelatin and 29.85g of glycerin to a reaction flask, stir, and place in a vacuum oven at 60℃. After reacting for 3 days, remove the flask to obtain the desired uniform elastomer raw rubber.

[0094] 50g of the above-mentioned elastomer raw rubber was mixed with 0.5g of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS) on a Hacker mixer for 20 minutes at a temperature of 45°C and a speed of 60 rpm. Then, 10g of the mixture was placed in a polytetrafluoroethylene mold and pressed into a sheet on a vacuum tablet press at a temperature of 45°C for 20 minutes to obtain an elastomer film with a thickness of 1mm.

[0095] Comparative Example 3

[0096] Add 29.85g of gelatin, 29.85g of glycerol and 5g of citric acid solution to a reaction flask, stir and place in a vacuum oven at 60℃. After reacting for 3 days, remove the flask to obtain the desired uniform elastomer raw rubber.

[0097] 50g of the above-mentioned elastomer raw rubber and 12.5g of ultrasonically dispersed carbon nanotubes were mixed in a Hacker mixer for 20 minutes at a temperature of 45°C and a rotation speed of 60 r / min. Then, 10g was placed in a polytetrafluoroethylene mold and pressed into a sheet using a vacuum tablet press at a temperature of 45°C for 20 minutes to obtain an elastomer film with a thickness of 1 mm.

[0098] Comparative Example 4

[0099] Add 20g of gelatin, 20g of glycerin and 40g of water to a reaction flask, stir and place in a vacuum oven at 65℃. After reacting for 3 days, remove the flask to obtain the desired uniform elastomer raw rubber.

[0100] Take 10g of the above elastomer raw rubber and place it in a polytetrafluoroethylene mold. Place it on a vacuum tablet press and press it into a sheet. Set the temperature to 50℃ and the pressing time to 25min to obtain an elastomer film with a thickness of 1mm.

[0101] The following performance tests were performed on the elastomer films prepared in the embodiments and comparative examples of the present invention:

[0102] 1. Mechanical property testing can refer to standard GB / T 16491-2008. The specific test methods are as follows:

[0103] The elastomer films prepared in Examples 1-6 and Comparative Examples 1-4 were made into dumbbell-shaped samples, and their mechanical strength was measured at room temperature using a universal testing machine. During the test, the samples were stretched axially until they broke at a stretching speed of 20 mm / min. The results are shown in Table 2. The mechanical properties of the elastomer films in Examples 1-3 with the addition of solution A were significantly better than those in Comparative Example 1. The mechanical properties of the elastomer films in Examples 4-6 with the addition of solution B in addition to solution A were also significantly better than those in Comparative Example 3 with only solution A. Furthermore, compared with the mechanical properties of the gelatin hydrogel in Comparative Example 4, the mechanical properties of the elastomer films were significantly enhanced.

[0104] 2. For conductivity testing, please refer to standard JJG 508-2004. The specific test method is as follows:

[0105] The resistance of the elastomer films prepared in Examples 1-6 and Comparative Examples 1-3 was measured using a four-probe resistivity meter. To ensure resistance uniformity, five locations were selected in the samples: the center of the sample and four locations 1 cm away from the center of the sample. The resistivity was measured at each location, and the conductivity was corrected using correction software. The results are shown in Table 2. The conductivity of the elastomer membranes in Examples 1-3 after adding solution A was significantly higher than that of the elastomer membrane in Comparative Example 1. The elastomer membrane in Comparative Example 2, with the addition of an electroactive substance, showed a significant increase in conductivity, but its tensile strength was low. In Comparative Example 3, the addition of solution A to the electroactive substance significantly improved both conductivity and tensile strength. The elastomer membranes in Examples 4-6, with the addition of solution B to solution A, showed significantly higher conductivity and tensile strength than the elastomer membrane in Comparative Example 3 with only solution A. This indicates that the addition of solution A improved the conductivity and mechanical properties of the elastomer material. At the same time, the addition of solution B, as a salt solution, not only achieved synergistic toughening of anions and cations but also increased the ionic conductive network, further enhancing the conductivity and mechanical properties of the elastomer material.

[0106] 3. Adhesion test

[0107] A circular elastomeric membrane with a diameter of 3 cm was fixed to a push-pull tensioner, then applied to the skin for 10 seconds before being slowly removed. The adhesion force was measured using a digital force gauge. The results are shown in Table 2. The elastomeric membranes prepared in Examples 3 and 4 showed adhesion forces comparable to or even better than those of the hydrogel elastomeric membrane in Comparative Example 4.

[0108] Table 2

[0109]

[0110] 4. Mechanical properties of elastomers after fracture healing

[0111] The elastomer diaphragms prepared in Examples 4-6 were cut in half, and then near-infrared lasers were used to briefly and locally melt and then solidify near the cracks or cuts to achieve fracture healing. The mechanical properties of the fracture-healed elastomer diaphragms were tested, and the results are shown in Table 3. The results show that the mechanical properties are almost identical to those before fracture.

[0112] Table 3

[0113] Material Tensile strength (kPa) Elongation at break (%) Example 4 468 114.12 Example 5 512 387.32 Example 6 589 370.21

[0114] 5. For antibacterial performance testing, please refer to standard GB / T 21510-2008. The specific method is as follows:

[0115] First, two identical elastomeric membranes prepared in Comparative Example 1 and the elastomeric membrane from Example 1 were placed at room temperature for 7 days, and then the changes in the materials themselves were observed. Next, the elastomeric membranes from Comparative Example 1 and Example 1 were respectively immersed in a bacterial solution of a certain concentration (approximately 10). 6 Incubate a bacterial suspension of Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) at CFU / ml for 12 h; after incubation, inoculate the bacterial suspension (diluted appropriately) onto the surface of a solid nutrient medium, incubate at 37℃ for 12-24 h, remove the culture dish, take a picture and count the bacteria, and calculate the inhibition rate.

[0116] The results showed that the elastomer membrane of Comparative Example 1 began to mold on its substrate after 7 days, with blue mold spots appearing on the material; while the elastomer membrane of Example 1 showed no changes and no signs of mold. Bacterial survival was also observed; the elastomer membrane of Example 1 had very few cell colonies, significantly fewer than the elastomer membrane of Comparative Example 1, indicating that the elastomer membrane of Example 1 with added solution A effectively inhibited bacterial survival.

Claims

1. An electrically conductive gelatin elastomer material employing a gelatin-based elastomer gum, characterized in that The elastomer material is obtained by blending raw materials including the following components: Elastomer raw rubber, electroactive substance and solution B; Each component is in weight fraction: Elastomer raw rubber 100 parts by weight; Electroactive substance 1-50 parts by weight; Solution B 10-50 parts by weight; The elastomer raw rubber is obtained by melting raw materials including the following components: Gelatin, plasticizer and solution A; Each component is in weight fraction: Gelatin 20-200 parts by weight; Plasticizer 100 parts by weight; Solution A 10-30 parts by weight; The solution A is at least one of citric acid solution, acetic acid solution, boric acid solution; The preparation method of the elastomer raw rubber includes: The components are melted to obtain the elastomer raw rubber according to the weight fraction; The melting temperature is 55-95℃, and the reaction time is 2-10 days; The electroactive substance is at least one of conductive polymer, conductive filler; The solution B is at least one of sodium chloride solution, potassium chloride solution, sodium sulfate solution, lithium bromide solution.

2. The conductive gelatin elastomer material according to claim 1, wherein: Each component is in weight fraction: Elastomer raw rubber 100 parts by weight; Electroactive substance 5-40 parts by weight; Solution B 20-30 parts by weight.

3. The conductive gelatin elastomer material according to claim 1, wherein: The components of the elastomer raw rubber are in weight fraction: Gelatin 30-150 parts by weight; Plasticizer 100 parts by weight; Solution A 15-20 parts by weight.

4. The conductive gelatin elastomer material according to claim 1, wherein: The glass transition temperature of the elastomer raw rubber is -90℃-65℃, and the gelation transition temperature is 20℃-50℃.

5. The conductive gelatin elastomer material according to claim 1, wherein: The plasticizer is at least one of glycerol, syrup.

6. The conductive gelatin elastomer material according to claim 1, wherein: The glass transition temperature of the elastomer material is -90°C to 45°C, the gelation transition temperature is 30°C to 60°C, the electrical conductivity is 33.61 x 10 -4 - 310.21 x 10 -4 S / m, and the tensile strength is 133 to 700 KPa.

7. The conductive gelatin elastomer material according to claim 1, wherein: The electroactive substance is at least one of graphene oxide, reduced graphene oxide, carbon nanotube, silver nanowire, liquid metal.

8. A process for the preparation of an electroconductive gelatin elastomer material as claimed in any one of claims 1-7, characterized in that The method includes one of the following four methods: The components are mixed to obtain the elastomer material according to the weight fraction; The components are mixed and solidified in situ to obtain the elastomer material according to the weight fraction; The components are mixed and 3D printed to obtain the elastomer material according to the weight fraction; The electroactive substance is printed between two layers of elastomer raw rubber to form a sandwich structure to obtain the elastomer material.

9. The preparation method of the conductive gelatin elastomer material according to claim 8, wherein: The 3D printing is coaxial 3D printing.

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