CN-119505309-B - High-sensitivity bicontinuous thin film electrode and preparation method thereof

Abstract

The invention discloses a high-sensitivity bicontinuous thin film electrode and a preparation method thereof, and belongs to the technical field of wearable sensing. The preparation method comprises the steps of preparing a polymer solution, namely adding polymer powder into a good solvent respectively, dissolving the polymer powder, stirring the polymer powder uniformly to obtain a polymer solution, preparing a liquid metal-polymer mixed solution, namely adding liquid metal into the polymer solution, uniformly dispersing the mixed solution by a refiner to obtain the liquid metal-polymer mixed solution, and preparing a bicontinuous film electrode, namely removing the good solvent from the uniformly dispersed mixed solution by means of heating or freeze drying and the like to obtain the bicontinuous film electrode. Compared with the prior art, the invention has the advantages that the stability of monitoring signals of the epidermis electrode in various epidermis deformation scenes and dynamic monitoring environments can be realized, and the characteristic electrophysiological signals in disease scenes can be monitored with high signal-to-noise ratio.

Inventors

• ZHANG YE
• LU JIANG
• LI QIANMING

Assignees

• 南京大学

Dates

Publication Date

20260508

Application Date

20241117

Claims (6)

1. 1. A preparation method of a high-sensitivity bicontinuous film electrode comprises the steps of, The preparation method comprises the steps of respectively adding polymer powder into good solvents, dissolving the polymer powder, and stirring the mixture uniformly to obtain a polymer solution, wherein the polymer solution is an ethylene/vinyl acetate-polyethylene oxide solution, and the preparation process comprises the steps of dissolving 5.0-10.0 wt% of ethylene/vinyl acetate particles in anisole, and magnetically stirring the mixture at the temperature of 90-98 ℃ to obtain an ethylene/vinyl acetate solution, dissolving 0.2-4.0 wt% of polyethylene oxide powder in the ethylene/vinyl acetate solution, and magnetically stirring the mixture at the temperature of 25-40 ℃ to obtain an ethylene/vinyl acetate-polyethylene oxide solution; preparing a liquid metal-polymer mixed solution, namely adding the liquid metal into the polymer solution, and uniformly dispersing the mixed solution by using a homogenizer to obtain the liquid metal-polymer mixed solution; The preparation method comprises the steps of preparing a bicontinuous film electrode, namely removing a good solvent from a uniformly dispersed mixed solution in a heating or freeze drying mode to obtain the bicontinuous film electrode, wherein the bicontinuous film electrode comprises liquid metal and a polymer network, the liquid metal is used as a fluid phase of the electrode, a mutually-communicated continuum is formed in the bicontinuous film, and the polymer network is in a dispersed three-dimensional porous network structure, is connected with a liquid metal oxide layer and is adhered to the surface of skin.
2. 2. The method for preparing a high-sensitivity bicontinuous thin film electrode according to claim 1, wherein, The preparation of the liquid metal-macromolecule mixed solution comprises the preparation of gallium indium alloy-ethylene/vinyl acetate-polyethylene oxide mixed solution, gallium-ethylene/vinyl acetate-polyethylene oxide mixed solution and gallium indium tin alloy-ethylene/vinyl acetate-polyethylene oxide mixed solution.
3. 3. The method for preparing a high-sensitivity bicontinuous thin film electrode according to claim 2, wherein, The preparation process of gallium indium alloy-ethylene/vinyl acetate-polyethylene oxide mixed solution comprises the following steps: mixing liquid metal gallium indium alloy with ethylene/vinyl acetate-polyethylene oxide solution to obtain initial mixed solution; and (3) placing the initial mixed solution at a temperature of 25-40 ℃, and stirring and shearing the initial mixed solution at a speed of 8000-15000 rpm by using a handheld refiner to obtain the gallium-indium alloy-ethylene/vinyl acetate-polyethylene oxide mixed solution.
4. 4. The method for preparing a high-sensitivity bicontinuous thin film electrode according to claim 2, wherein, The preparation process of the gallium-ethylene/vinyl acetate-polyethylene oxide mixed solution comprises the following steps: mixing liquid gallium metal with an ethylene/vinyl acetate-polyethylene oxide solution to obtain an initial mixed solution; And (3) placing the initial mixed solution at a temperature of 25-40 ℃, and stirring and shearing the initial mixed solution at a speed of 8000-15000 rpm by using a handheld refiner to obtain the gallium-ethylene/vinyl acetate-polyethylene oxide mixed solution.
5. 5. The method for preparing a high-sensitivity bicontinuous thin film electrode according to claim 2, wherein, The preparation process of the gallium indium tin alloy-ethylene/vinyl acetate-polyethylene oxide mixed solution comprises the following steps: mixing liquid metal gallium indium tin alloy with ethylene/vinyl acetate-polyethylene oxide solution to obtain initial mixed solution; and (3) placing the initial mixed solution at a temperature of 25-40 ℃, and stirring and shearing the initial mixed solution at a speed of 8000-15000 rpm by using a handheld refiner to obtain the gallium indium tin alloy-ethylene/vinyl acetate-polyethylene oxide mixed solution.
6. 6. The high-sensitivity bicontinuous thin film electrode prepared by the method for preparing the high-sensitivity bicontinuous thin film electrode according to any one of claims 1 to 5, which is characterized by comprising liquid metal and a polymer network, wherein the liquid metal is used as a fluid phase of the electrode to form a mutually communicated continuum in the bicontinuous thin film, and the polymer network is in a dispersed three-dimensional porous network structure, is connected with a liquid metal oxide layer and is adhered to the surface of skin.

Description

High-sensitivity bicontinuous thin film electrode and preparation method thereof Technical Field The invention relates to the technical field of wearable sensing, in particular to a high-sensitivity bicontinuous thin film electrode and a preparation method thereof. Background The electrophysiological signals are used as direct expression of the electrical activity in organisms, contain rich physiological and pathological information and have irreplaceable values for clinical diagnosis and health management. These signals are typically monitored non-invasively via epidermal electrodes and even small electrophysiological fluctuations reflect complex physiological state changes within the living organism. Early detection of certain potential micro-lesions (e.g., arrhythmia, early signs of myocardial infarction) can greatly reduce the risk of serious complications. Therefore, accurate capture of electrophysiological signals is important for preventing serious complications and improving treatment effects, especially in early recognition of potential micro-lesions such as arrhythmia and myocardial infarction. The development of highly sensitive epidermal electrodes that accurately monitor these small changes is critical to the improvement of medical diagnosis and health management levels. However, current advances in epidermal electrode technology face significant challenges. The main problem is the loss of signal at the electrode-skin interface and the attenuation of the electron transport process. In order to realize high-sensitivity monitoring, the ideal electrode material has two characteristics of high conductivity and low interface impedance. However, existing electrode materials have limitations in both aspects. Metal electrodes, such as gold and platinum, are known for their excellent electrical conductivity, but in practical applications they are difficult to form a stable and low impedance interface with the skin, mainly due to the differences in mechanical properties between the metal and the skin tissue. This difference results in interface instability and high interface impedance, which in turn affects the efficiency and accuracy of signal transmission. On the other hand, the conductive polymer electrode (such as polypyrrole, polyaniline and the like) and the conductive composite electrode can form a tighter interface with the skin, so that signal attenuation at the interface is reduced, however, the conductive performance of the materials is relatively limited, so that certain loss exists in the signal transmission process, and the sensitivity of the electrode is limited. In the related art, as in chinese patent CN106798556a, a portable electrocardiograph system based on an electronic epidermis is provided, which includes an analog portion, a main control MCU, and an electronic epidermis electrocardiograph electrode, where the analog portion and the main control MCU are made of flexible circuit boards and connected to the electronic epidermis electrocardiograph electrode, and the main control MCU includes a data processing and analyzing circuit and a bluetooth BLE communication portion. For carrying out correlation research on electrocardiosignals and human body motion change, the flexible circuit board is also integrated with a triaxial sensor, and the electronic epidermis electrocardiosignal electrode is in a serpentine interconnection island bridge structure. The scheme aims at improving the measurement precision of the electrocardiosignals of the human body in a motion or static state so as to inhibit interference signals caused by the motion of the human body, but the scheme has the defect that any technical teaching is not given for how to reduce the loss of the electrophysiological signals in the transmission process and crossing interfaces. From the above, although the prior art has achieved monitoring of electrophysiological signals to some extent, it is limited by the problems of conductivity and interfacial impedance of the electrode material, and the maximum sensitivity of the currently reported epidermal electrode is only 5 μv·n-1, which is not enough to accurately capture slight characteristic signal changes. Therefore, how to improve the conductivity of the electrode material and reduce the interface impedance of the electrode material to improve the sensitivity of the electrode is a problem to be solved in the current field. Disclosure of Invention 1. Technical problem to be solved Aiming at the problems of signal loss at the interface between the electrode and the skin and the loss of the signal in the transmission process in the prior art, the invention provides a high-sensitivity bicontinuous thin film electrode and a preparation method thereof, which can realize the stability of monitoring signals of the epidermis electrode in various epidermis deformation scenes and dynamic monitoring environments and monitor characteristic electrophysiological signals in disease scenes with hi