Stimulus-responsive on-demand adhesion intelligent conductive hydrogel electrode patch as well as preparation method and application thereof

Abstract

The invention discloses a stimuli-responsive on-demand adhesion intelligent conductive hydrogel electrode patch and a preparation method and application thereof, and the preparation method comprises the following steps: uniformly mixing a stimuli-responsive phase transition substrate material, a monomer of a stimuli-responsive color change component, a conductive component, a viscous component, an initiator and a cross-linking agent according to a ratio; then injecting the mixture into a mold, and carrying out initiated polymerization to obtain a hydrogel electrode patch; the stimulus-responsive color change component is a polymer having a UCST temperature or a polymer having a stimulus-responsive color change group. The stimuli-responsive on-demand adhesion conductive hydrogel can be well attached to the skin under the use condition, the signal detection quality is improved, and the signal-to-noise ratio is increased; and after monitoring is completed, the adhesive force with the epidermis of the human body can be reduced in a mild stimulation mode, and lossless removal is achieved. In addition, due to the existence of the stimulus-responsive color change component, the strength of the adhesion performance can be effectively and visually indicated.

Description

Technical Field

[0001] This application belongs to the fields of biomedical polymer materials and flexible electronics technology, and relates to a stimulus-responsive adhesion-on-demand intelligent conductive hydrogel electrode patch, its preparation method and applications. Background Art

[0002] The statements herein only provide background art related to the present invention and do not necessarily constitute prior art.

[0003] In recent years, with the rapid development of artificial intelligence and intelligent diagnosis technologies, wearable bioelectronic devices have been widely used in fields such as personalized health monitoring, precision medicine, and behavior analysis. As one of the basic manifestations of bioenergy, bioelectric signals are of great significance for deeply understanding the functional and pathological mechanisms of biological activities. As the core component in bioelectrical impedance technology that directly contacts the human body, a bioelectrode is a key component for monitoring bioelectric signals such as electrocardiogram and electromyogram. Currently, bioelectrodes are mainly divided into two categories: invasive and non-invasive. Although invasive electrodes can provide higher signal quality, the trauma and pain problems they bring limit their widespread application. The human skin has characteristics such as softness, easy deformation, and easy folding. During exercise, due to the pulling of muscles, gaps are likely to occur on the skin surface, which affects the conformal contact between non-invasive bioelectrodes and the skin, increases the interfacial impedance, and thus reduces the quality of signal monitoring. Therefore, developing a non-invasive bioelectrode that can form a stable conformal contact with the skin to accurately and faithfully record physiological signals is of great significance for improving the accuracy and comfort of human physiological monitoring.

[0004] The key to solving the above problems lies in improving the flexibility of the electrode material and enhancing its conformal performance with the human skin. Currently, there are mainly two ways to solve this problem: one is to reduce the thickness of the electrode, and the other is to improve the adhesion performance of the electrode, thereby enhancing the conformal ability between the electrode and the skin during the working state. Hydrogels, due to their three-dimensional network structure and mechanical properties similar to human tissues, have become ideal materials for solving the mechanical mismatch problem between soft biological tissues and rigid bioelectronic devices.

[0005] So far, various hydrogel-based electrodes have been used to detect human physiological information, such as joint movement, pulse, blood oxygen, and body temperature. However, existing hydrogel materials still face many challenges, such as difficult-to-adjust adhesion performance, mechanical mismatch at the electrode-epidermis interface, and insufficient electrical signal transmission efficiency. To improve the accuracy and high fidelity of physiological signal monitoring, it is crucial to develop hydrogel materials with a modulus matching that of human skin, adjustable adhesion performance, and excellent electrical conductivity. Summary of the Invention

[0006] Aiming at the deficiencies of the existing technologies, the purpose of the present invention is to provide a stimulus-responsive on-demand adhesion intelligent conductive hydrogel electrode patch, a preparation method thereof, and an application thereof. The on-demand adhesion of the hydrogel in the present invention is achieved by adjusting the gel-sol phase transition of the polymer material, and the ionic conductivity is achieved by adding free ions, ionic liquids or deep eutectic solvents to the gel network. First, the gel-sol phase transition of the hydrogel occurs under different stimuli to achieve the switching between high adhesion and low adhesion, and at the same time, the change in the gel color is used to indicate the strength of the adhesion. When used as a bioelectrode to monitor physiological signals, it can not only achieve stable and high-quality signal monitoring, but also achieve the effect of on-demand fitting and removal.

[0007] To achieve the above object, the present invention is realized through the following technical solutions:

[0008] In the first aspect, the present invention provides a preparation method of a stimulus-responsive on-demand adhesion intelligent conductive hydrogel electrode patch, including the following steps:

[0009] Mix a monomer with a stimulus-responsive phase transition substrate material, a stimulus-responsive color change component, a conductive component, a viscous component, an initiator, and a crosslinking agent in proportion and uniformly, and then inject the mixture into a mold. After initiation polymerization, a hydrogel electrode patch is obtained;

[0010] The stimulus-responsive color change component is a polymer with an upper critical solution temperature (UCST) or a polymer with a stimulus-responsive color change group.

[0011] The stimulus-responsive on-demand adhesion intelligent conductive hydrogel electrode patch of the present invention has the characteristics of on-demand adhesion, high stretchability, transparency, biocompatibility, and low interfacial impedance. It is used as a bio-patch electrode to detect human physiological signals. This stimulus-responsive on-demand adhesion conductive hydrogel can be well adhered to the skin under the use conditions, improving the quality of signal detection and the signal-to-noise ratio; after the monitoring is completed, the adhesion force between the hydrogel and the human epidermis can be reduced by a mild stimulus method to achieve non-destructive removal. In addition, due to the presence of the stimulus-responsive color change component, an effective visual indication of the strength of the adhesion performance can be made.

[0012] In some embodiments, in the mixture, the concentration of the stimulus-responsive phase transition substrate material is 1-10 wt%; the concentration of the stimulus-responsive color change component is 0.5-3 mol / L; the concentration of the viscous component is 0.5-5 wt%.

[0013] Preferably, the concentration of the conductive component is 1-5 wt%; the concentration of the initiator is 0.1-0.5 mol / L; the concentration of the crosslinking agent is 0.1-1 mol / L.

[0014] In some embodiments, the stimulus-responsive phase-transition substrate material is selected from at least one of gelatin, silk fibroin, or poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer.

[0015] In some embodiments, the polymer having a UCST temperature is polyacrylic acid-polyacrylamide copolymer, polymethacrylamide, or poly(N-isopropylacrylamide).

[0016] Preferably, the polymer having a stimulus-responsive color-changing group is a spiropyran group-containing polymer or an azobenzene group-containing polymer.

[0017] In some embodiments, the initiator is a photoinitiator, selected from at least one of 1-hydroxycyclohexyl phenyl ketone (IRG1173), 2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone (IRG 2959), or 2,4,6-(trimethylbenzoyl) diphenylphosphine oxide (TPO).

[0018] Preferably, the photoinitiator is 1-hydroxycyclohexyl phenyl ketone (IRG 1173).

[0019] In some embodiments, the crosslinking agent is polyethylene glycol diacrylate or methoxypolyethylene glycol acrylate.

[0020] Preferably, the crosslinking agent is polyethylene glycol diacrylate or N,N-methylenebisacrylamide, preferably polyethylene glycol diacrylate.

[0021] In some embodiments, the conductive component is free ions, ionic liquid, or eutectic solvent.

[0022] Preferably, the free ions are Na + 、Cl - or K + .

[0023] Preferably, the ionic liquid is 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, or 1-butyl-3-methylimidazolium hydrogensulfate.

[0024] Preferably, the eutectic solvent is choline chloride / ethylene glycol, choline chloride / glycerol, choline chloride / urea, or choline chloride / oxalic acid.

[0025] In some embodiments, the viscous component is selected from at least one of dopamine, tannic acid, gallic acid, or phytic acid.

[0026] In some embodiments, the initiation polymerization is ultraviolet light-initiated polymerization reaction, and the time for initiation polymerization is 1-10 min.

[0027] In some embodiments, the manner of the stimulation is temperature stimulation, light stimulation or chemical substance stimulation.

[0028] Preferably, the range of the temperature stimulation is 30-40 °C, preferably 35 °C;

[0029] The light stimulation is ultraviolet light stimulation or infrared light stimulation. The wavelength of the ultraviolet light is 356 nm, and the wavelength of the infrared light is 808 nm;

[0030] The chemical substance is glucose, acid-base or H 2 O 2 .

[0031] In some embodiments, the material of the mold is glass or polytetrafluoroethylene.

[0032] The shape of the hydrogel electrode patch can be prepared by cutting, direct mold polymerization or 3D printing.

[0033] In a second aspect, the present invention provides a stimulus-responsive adhesion-on-demand intelligent conductive hydrogel electrode patch prepared by the preparation method.

[0034] In some embodiments, the thickness of the hydrogel electrode patch is 1-3 mm.

[0035] In a third aspect, the present invention provides the application of the stimulus-responsive adhesion-on-demand intelligent conductive hydrogel electrode patch in the monitoring of human physiological electrical signals.

[0036] In some embodiments, the physiological electrical signals are selected from electromyographic signals, electroencephalographic signals or electrocardiographic signals.

[0037] In some embodiments, the electrodes used in the stimulus-responsive adhesion-on-demand intelligent conductive hydrogel electrode patch are silver electrodes, silver / silver chloride electrodes, gold electrodes, copper electrodes or carbon-based-polymer composite electrodes.

[0038] The beneficial effects obtained by one or more of the above embodiments of the present invention are as follows:

[0039] The present invention relies on the sol-gel phase transition of the thermosensitive polymer material at high temperature-low temperature to achieve stimulus-responsive adhesion-on-demand. It has the advantages of simple raw materials used, good biocompatibility, simple preparation method, etc. The present invention introduces a polymer structure gel with stimulus-responsive color change. On the one hand, it improves the mechanical properties of the gel, and on the other hand, it matches the gel phase transition temperature with the color transition point to realize the visual monitoring of the gel adhesion force.

[0040] The present invention introduces ions to construct an ion conductive network, thereby ensuring the flexibility of the gel network and facilitating the processing and assembly of the device; ensuring the optical performance of the gel network and improving the accuracy of the color indication adhesion; ion conduction is similar to the transmission mode of human physiological electrical signals, and more effectively reduces the interface impedance between the gel and human tissue, which is beneficial to the improvement of the signal-to-noise ratio of physiological electrical signal monitoring.

[0041] The stimulus-responsive on-demand conductive hydrogel prepared by the present invention has the characteristics of on-demand adhesion, high stretchability, transparency, biocompatibility, and low interfacial impedance. The gel is transparent under body temperature stimulation and has a good fit with the skin, effectively reducing the signal-to-noise ratio of physiological signal monitoring and improving the quality of signal detection. At the same time, after use, it can be de-adhesed by low-temperature stimulation of an ice bag. At this time, the gel is opaque, has an indicative effect, and can be easily peeled off from the skin. In addition, since this gel has excellent biocompatibility, it provides a way of thinking for in vivo and in vitro physiological signal monitoring, and provides an economical and convenient method for the development of future smart diagnosis and treatment and health monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0043] Figure 1 . Schematic diagram of the preparation of stimulus-responsive on-demand adhesion smart conductive hydrogel.

[0044] Figure 2 .Transmittance of stimulus-responsive on-demand adhesion smart conductive hydrogel (a) Transmittance of GP gel in the visible light region at 10℃ and 35℃; (b) Transmittance of GP gel at 600nm wavelength after ten cycles at 10℃ and 35℃ and actual display picture.

[0045] Figure 3 . Schematic diagram and results of the adhesion performance test of stimulus-responsive on-demand adhesion smart conductive hydrogel (a) Lap shear adhesion test (b) Schematic diagram of the 90° peel adhesion test and the adhesion results of hydrogel with pig skin, glass, copper sheet, and nitrile rubber at 10°C and 35°C.

[0046] Figure 4 .SEM images of the adhesion surface of stimulus-responsive on-demand adhesion smart conductive hydrogel to pig skin at 10°C and 35°C.

[0047] Figure 5 .Contact angle of water of stimuli-responsive on-demand adhesion smart conductive hydrogel at 10°C and 35°C.

[0048] Figure 6. Mechanical property test diagrams of the stimulus-responsive on-demand adhesion intelligent conductive hydrogel, (a) uniaxial tensile property; (b) compression property.

[0049] Figure 7 . Frequency-impedance relationship diagram of the stimulus-responsive on-demand adhesion intelligent conductive hydrogel.

[0050] Figure 8 . Cell compatibility test diagrams of the stimulus-responsive on-demand adhesion intelligent conductive hydrogel (a) CCK-8 cytotoxicity test diagram (b) live / dead staining result diagram.

[0051] Figure 9 . Electrode display diagram of the stimulus-responsive on-demand adhesion intelligent conductive hydrogel.

[0052] Figure 10 . Usage process diagram of the electrode of the stimulus-responsive on-demand adhesion intelligent conductive hydrogel.

[0053] Figure 11 . Comparison diagram of the results of testing EMG signals and signal-to-noise ratio between the electrode of the stimulus-responsive on-demand adhesion intelligent conductive hydrogel and commercial electrodes.

[0054] Figure 12 . Comparison diagram of the results of testing ECG signals between the electrode of the stimulus-responsive on-demand adhesion intelligent conductive hydrogel and commercial electrodes.

[0055] Figure 13 . Comparison diagram of EMG signal testing between the 16-channel electrode of the stimulus-responsive on-demand adhesion intelligent conductive hydrogel and silver / silver chloride electrode, where A is the test diagram; B is the comparison diagram of EMG signal power testing, and the commercial electrode in B is the silver / silver chloride electrode. Detailed implementation manners

[0056] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0057] The present invention will be further described below in conjunction with embodiments.

[0058] Unless otherwise specified, all are conventional methods. Unless otherwise specified, the raw materials can be obtained from public commercial channels, the test methods are all conventional methods, and the instrument settings are all the settings recommended by the manufacturers. The analysis methods in the embodiments of the present application are as follows:

[0059] The transmittance is tested by an ultraviolet spectrophotometer, and the test conditions are 10°C and 35°C, transmission mode, and the test range is the visible light region.

[0060] The adhesion performance was tested using a universal testing machine at test temperatures of 10 °C and 35 °C, and the test condition was a uniaxial tensile rate of 50 mm / min.

[0061] The mechanical properties were tested using a universal testing machine. The analysis instrument was a universal testing machine, and the analysis conditions were a uniaxial tensile rate of 100 mm / min and a compression test rate of 0.2 mm / min.

[0062] The microscopic morphology of the adhesion cross-section of the gel and pig skin at 10 °C and 35 °C was observed using a scanning electron microscope. The samples maintained at 10 °C or 35 °C were rapidly frozen with liquid nitrogen, sputter-coated with gold after freeze-drying, and observed at a voltage of 3 kV.

[0063] The contact angle of the gel with water at 10 °C and 35 °C was measured using a contact angle measuring instrument.

[0064] The impedance value of the gel at different frequencies was measured using a digital bridge.

[0065] The stimulus-responsive adhesion-on-demand intelligent conductive hydrogel electrode can be batch-prepared and stored in a simple manner. Here, the temperature-stimulus-responsive adhesion-on-demand intelligent conductive hydrogel electrode is placed on the human skin, and the body temperature triggers the gel electrode to adhere to the epidermis and exhibits high transparency, enabling physiological signal monitoring. After the test, it can be triggered by a simple ice pack at low temperature. At this time, the transparency of the gel decreases and the adhesion performance decreases, and it can be gently removed according to this instruction.

[0066] Using the stimulus-responsive adhesion-on-demand intelligent conductive hydrogel as an electrode, the electromyogram signal and electrocardiogram signal were monitored using an electromyogram signal monitor and an electrocardiogram signal monitor. And it can also be used as an electrode patch for a 16-channel electromyogram detector.

[0067] Example 1

[0068] Step 1: Prepare the hydrogel by a one-pot method. Select gelatin with temperature-stimulated gel-sol phase transition as the substrate to endow the hydrogel electrode patch with the property of temperature-stimulus-responsive adhesion-on-demand. Introduce the thermosensitive polyacrylamide-polyacrylic acid copolymer with UCST as the temperature-stimulus-responsive color change component, and use Na + in the system as the ionic conductive component. In addition, dopamine is introduced to improve the adhesion performance of the gel. Dopamine is oxidized and self-polymerized into polydopamine, and further oxidized and decomposed into polydopamine nanoparticles by a strong oxidant of hydrogen peroxide / sodium hydroxide, which increases the doping amount and ensures the transparency of the system. Finally, add the corresponding proportions of photoinitiator 1173 and crosslinker PEGDA-600, stir evenly and inject into a glass mold, and polymerize under ultraviolet light to obtain the hydrogel.

[0069] The contents of each substance are shown in Table 1:

[0070] Table 1

[0071]

[0072]

[0073] The rest is deionized aqueous solution.

[0074] Step 2: Prepare the hydrogel obtained in Step 1 into a cylinder with a diameter of 8 mm and a thickness of 1.5 mm according to the usage requirements, and combine it with Ag / AgCl to obtain a temperature-stimulus-responsive adhesion-on-demand intelligent conductive hydrogel electrode patch.

[0075] The transparency of the gel in the visible light range was detected using a UV-visible spectrophotometer. The transmittance was above 80% at 35 °C, 20.9% at 10 °C, and it showed good stability under ten temperature cycles.

[0076] The mechanical properties were tested using a universal testing machine. The tensile properties were tested at a tensile rate of 100 mm / min. It was found that the fracture stress of the material was 117.8 kPa, the fracture elongation rate could reach 1632%, and the stress at a compressive strain of 98% was 2.4 MPa, and the gel did not rupture.

[0077] The adhesion performance of the gel was tested through lap-shear adhesion tests and 90° peel adhesion tests. It was found that the gel had good adhesion effects on pig skin, glass, plastic, rubber, etc. at 35 °C. Among them, the adhesion force and adhesion strength to pig skin were 5.64 N and 99.28 N / m 2 ; the adhesion force of the gel to various substrates decreased at 10 °C, being 0.73 N and 3.81 N / m 2 .

[0078] The microscopic morphology of the adhesion cross-section of the gel and pig skin at 10 °C and 35 °C was observed using a scanning electron microscope. It was found that there were almost no gaps at 35 °C, while larger gaps appeared at 10 °C. The contact angle of the gel with water was measured using a contact angle measuring instrument to be 17.5° at 10 °C and 99.4° at 35 °C, indicating that the more hydrophilic characteristics at 35 °C are beneficial for better binding with the epidermis.

[0079] The impedance of the gel under variable frequency was tested using a digital bridge. It was found that the impedance was 455.9 Ω and 59.6 Ω at 100 Hz and 1 Hz respectively, indicating that it is suitable as a gel electrode patch for monitoring human physiological electrical signals.

[0080] Step 3: Place the hydrogel electrode on the human skin. The body temperature triggers the gel electrode to adhere to the epidermis and exhibit high transparency, enabling physiological signal monitoring. After the test, it can be gently removed by simply triggering it with an ice pack at low temperature. At this time, the gel transparency decreases and the adhesion performance decreases. The gel electrode patch is used to test the electromyogram signal of the arm, and the signal-to-noise ratio is 57.6 dB, which is higher than that of the commercial electrode (the signal-to-noise ratio is 7.4 dB) under the same test conditions. The gel electrode patch is used for electrocardiogram signal monitoring, and the signal intensity is higher compared with the commercial electrode. In addition, due to the simplicity of the gel electrode preparation method, it can also be used as the electrode patch of a 16-channel electromyogram detector to realize multi-channel electromyogram signal monitoring.

[0081] Perform performance tests on the samples prepared in the above-mentioned examples and comparative examples, taking Sample 1# as an example.

[0082] Figure 2 It is the transparency test of Sample 1#; (a) is the data graph of the material transparency in the visible light range tested by an ultraviolet spectrophotometer at 10°C and 35°C. It can be seen that the material has high transparency at 35°C and low transparency at 10°C. (b) is the transmittance at 600 nm under 10 temperature cycles. It can be seen that the optical properties of the material have good cyclic stability.

[0083] Figure 3 It is the schematic diagram and results of the adhesion performance test of Sample 1# (a) Lap shear adhesion test (b) Schematic diagram of 90° peel adhesion test and the adhesion force results of the hydrogel with pig skin, glass, copper sheet, and nitrile rubber at 10°C and 35°C. It can be seen that the material has good general adhesion at 35°C, and the adhesion performance decreases at 10°C, showing the characteristics of temperature-stimulated on-demand adhesion.

[0084] Figure 4 It is the SEM image of the adhesion surface of Sample 1# with pig skin at 10°C and 35°C. It is found that there are almost no gaps at 35°C, while larger gaps appear at 10°C, which proves again that it has high adhesion at 35°C and the adhesion performance decreases at 10°C, showing the characteristics of temperature-stimulated on-demand adhesion.

[0085] Figure 5 It is the contact angle of Sample 1# with water at 10°C and 35°C. The contact angle of Sample # at 35°C is higher than that at 10°C, indicating that the gel is more hydrophilic at high temperature, which is beneficial to forming a better bond with the epidermis and improving the adhesion performance.

[0086] Figure 6 It is the mechanical property test of Sample 1# at room temperature, including (a) uniaxial tensile property and (b) compression property, proving that the material has good mechanical properties.

[0087] Figure 7 It is the frequency-impedance relationship diagram of Sample 1#. By testing the impedance change of the gel in the range of 0.1 Hz to 10 5 Hz, it is proved that the gel material has good ionic conductivity and can be used as an electrode patch for monitoring human physiological electrical signals.

[0088] Figure 8 It is the cell compatibility test of Sample 1#. (a) is the test diagram of the CCK-8 cytotoxicity test. Mouse epithelial cells were cultured by the extraction solution method, sampled at 24 h and 48 h, stained with CCK-8 reagent, and tested and analyzed by an enzyme-linked immunosorbent assay (ELISA) reader to obtain data. It can be seen that the material has excellent biocompatibility. (b) is the cell live / dead staining diagram of Sample 1#. HUVECs were selected for 2D culture, and the cells were stained with a Calcein / PI kit. The live / dead proliferation status of the cells was observed by confocal fluorescence microscopy. Compared with the control group, the cells in the experimental group grew well and had good biocompatibility.

[0089] Figure 9 It is the display diagram of the gel electrode assembled from Sample 1#, showing simple mass production performance.

[0090] Figure 10 It is the usage process diagram of the gel electrode assembled from Sample 1#. The hydrogel electrode is placed on the human skin, and the body temperature triggers the gel electrode to adhere to the epidermis and shows high transparency, enabling physiological signal monitoring. After the test, it can be triggered by a simple ice pack at low temperature. At this time, the transparency of the gel decreases and the adhesion performance decreases, and it can be removed under warm conditions according to this instruction.

[0091] Figure 11 It is the comparison of the results of the electromyogram (EMG) signal test and the signal-to-noise ratio (SNR) between the gel electrode assembled from Sample 1# and a commercial electrode (3M, 2223CN). The SNR of the EMG signal obtained by the gel test is 57.6 dB. Under the same test conditions, the SNR of the EMG signal obtained by the commercial electrode test is 7.4 dB.

[0092] Figure 12 It is the comparison of the results of the electrocardiogram (ECG) signal test between the gel electrode assembled from Sample 1# and a commercial electrode (3M, 2223CN). The signal intensity is stronger and more accurate.

[0093] Figure 13 It is the 16-channel gel electrode assembled from Sample 1# and the comparison of the EMG signal test with a silver / silver chloride electrode. It shows good signal stability and signal accuracy, providing an economical and convenient method for the development of future intelligent diagnosis and treatment and health monitoring.

[0094] Example 2

[0095] The hydrogel is prepared by a one-pot method, which is different from Example 1 in that the raw materials are shown in Table 2.

[0096] Table 2

[0097]

[0098]

[0099] The rest is deionized aqueous solution.

[0100] Example 3

[0101] The hydrogel is prepared by a one-pot method, which is different from Example 1 in that the raw materials are shown in Table 3.

[0102] Table 3

[0103]

[0104] The rest is deionized aqueous solution.

[0105] Example 4

[0106] The hydrogel is prepared by a one-pot method, which is different from Example 1 in that the raw materials are shown in Table 4.

[0107] Table 4

[0108]

[0109]

[0110] The rest is deionized aqueous solution.

[0111] Example 5

[0112] The hydrogel is prepared by a one-pot method, which is different from Example 1 in that the raw materials are shown in Table 5.

[0113] Table 5

[0114] Component Concentration Silk fibroin 5 wt% Spiropyran derivative 1 mol / L Phytic acid 2 mol / L 1173 0.3 mol / L PEGDA-600 0.5 mol / L Choline chloride / glycerol 1 mol / L

[0115] The rest is deionized aqueous solution.

[0116] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a stimulus-responsive on-demand adhesive smart conductive hydrogel electrode patch, characterized in that: The steps include: The substrate material with a stimuli-responsive phase transition, the monomer of the stimuli-responsive color change component, the conductive component, the viscous component, the initiator and the cross-linking agent are mixed evenly in proportion, and then the mixture is injected into a mold, and polymerization is initiated to obtain a hydrogel electrode patch; The stimulus-responsive color-changing component is a polymer having a UCST temperature or a polymer having a stimulus-responsive color-changing group.

2. The method for preparing the stimulus-responsive on-demand adhesive smart conductive hydrogel electrode patch according to claim 1, characterized in that: In the mixture, the concentration of the stimulus-responsive phase-change base material is 1-10 wt %; the concentration of the stimulus-responsive color-changing component is 0.5-3 mol / L; and the concentration of the viscous component is 0.5-5 wt %; Preferably, the concentration of the conductive component is 1-5 wt %; the concentration of the initiator is 0.1-0.5 mol / L; and the concentration of the cross-linking agent is 0.1-1 mol / L.

3. The method for preparing the stimulus-responsive on-demand adhesion smart conductive hydrogel electrode patch according to claim 1, characterized in that: The stimulus-responsive phase-change substrate material is selected from at least one of gelatin, silk fibroin, or poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymers.

4. The method for preparing the stimulus-responsive on-demand adhesive smart conductive hydrogel electrode patch according to claim 1, characterized in that: The polymer having the UCST temperature is polyacrylic acid-polyacrylamide copolymer, polymethacrylamide or poly(N-isopropylacrylamide); Preferably, the polymer having a stimulus-responsive color-changing group is a polymer containing a spiropyran group or a polymer containing an azobenzene group.

5. The method for preparing the stimulus-responsive on-demand adhesive smart conductive hydrogel electrode patch according to claim 1, characterized in that: The initiator is a photoinitiator, selected from at least one of 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-4-(2-hydroxyethoxy)-2-methylpropiophenone or 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide; Preferably, the photoinitiator is 1-hydroxycyclohexyl phenyl ketone; Or, the cross-linking agent is polyethylene glycol diacrylate or N,N-methylenebisacrylamide; Preferably, the cross-linking agent is polyethylene glycol diacrylate.

6. The method for preparing the stimulus-responsive on-demand adhesive smart conductive hydrogel electrode patch according to claim 1, characterized in that: The conductive component is a free ion, an ionic liquid or a deep eutectic solvent; Preferably, the free ion is Na + , Cl - or K + ; Preferably, the ionic liquid is 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate or 1-butyl-3-methylimidazolium hydrogen sulfate; Preferably, the deep eutectic solvent is choline chloride / ethylene glycol, choline chloride / glycerol, choline chloride / urea or choline chloride / oxalic acid.

7. The method for preparing the stimulus-responsive on-demand adhesion smart conductive hydrogel electrode patch according to claim 1, characterized in that: The sticky component is selected from at least one of dopamine, tannic acid, gallic acid or phytic acid; Or, the stimulation is in the form of temperature stimulation, light stimulation or chemical stimulation; Preferably, the temperature stimulation ranges from 30 to 40°C, preferably 35°C; The light stimulation is ultraviolet light stimulation or infrared light stimulation, the wavelength of ultraviolet light is 356nm, and the wavelength of infrared light is 808nm; The chemical substances are glucose, acid, base or H2O2.

8. A stimulus-responsive on-demand adhesive smart conductive hydrogel electrode patch, characterized in that: Prepared by the preparation method described in any one of claims 1 to 7.

9. Application of the stimulus-responsive on-demand adhesion smart conductive hydrogel electrode patch of claim 8 in monitoring physiological electrical signals of the human body.

10. The use according to claim 9, characterized in that: The physiological electrical signal is selected from electromyographic signal, electroencephalographic signal or electrocardiographic signal; Alternatively, the electrode used in the stimulus-responsive on-demand adhesion smart conductive hydrogel electrode patch is a silver electrode, a silver / silver chloride electrode, a gold electrode, a copper electrode or a carbon-based-polymer composite electrode.

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