WO2022217952A1

WO2022217952A1 - Method for preparing fibrous membrane dry electrode directly on skin by spinning

Info

Publication number: WO2022217952A1
Application number: PCT/CN2021/137760
Authority: WO
Inventors: 刘志远; 李光林; 李青松; 于玫; 赵阳; 李向新
Original assignee: 中国科学院深圳先进技术研究院
Priority date: 2021-04-12
Filing date: 2021-12-14
Publication date: 2022-10-20
Also published as: CN113100773A

Abstract

A method for preparing a fibrous membrane dry electrode directly on the skin by spinning, comprising the following steps: (1) mixing a spinning polymer, a conductive material, and a solvent in proportion to form a uniform spinning solution; and (2) directly spinning the spinning solution on the skin to prepare a fibrous membrane dry electrode. According to the method for preparing a fibrous membrane dry electrode directly on the skin by spinning, physiological electrical signals can be detected, and the problems of complex preparation processes, poor skin fit, air and sweat impermeabilities, etc. of common dry electrodes are solved; the fibrous network structure formed on the skin combines a fibrous structure with a conductive material, thereby effectively improving the stretchability and skin fit of the electrode.

Description

A method for preparing fiber membrane dry electrodes by spinning directly on the skin

technical field

The invention belongs to the technical field of novel flexible electrodes, in particular to a method for preparing a fiber membrane dry electrode by spinning directly on the skin.

Background technique

Due to stroke, cerebrovascular disease and accidental injury, a large number of patients suffer from inconvenience, paralysis or even amputation. for

With the continuous development of flexible wearable devices, more and more attention has been paid to physiological signal dry electrodes that play an important signal transmission role in human sensing and machine interfaces. Dry electrodes are commonly used structurally stable electrodes that are most likely to be used for long-term wear and continuous monitoring. However, dry electrodes often have some problems, such as poor adhesion to the skin, complicated preparation, and poor stretchability.

There are many dry electrode products reported in the literature and commercialized, but they can be roughly divided into the following categories: (1) hard materials, such as metal sheets; (2) flexible materials, such as conductive polymer films, graphene, carbon Nanotubes, and polymer composite materials based on them; (3) Structured materials, such as fabric electrodes, structured metal films, metal wires, conductive polymers, etc.

The above dry electrodes have some problems in terms of preparation and performance. For example, the stretchability and flexibility of the metal sheet electrodes are poor, and they cannot be closely attached to the skin; if flexible or structured materials are used, or the electrodes are thicker and cannot be closely contacted with the skin The fit of the electrode is poor, or the electrode needs to be ultra-thin thickness, which is more complicated to process; the electrode has no air permeability or poor air permeability.

technical problem

In view of the existing technical problems raised in the background art, the present invention proposes a method for directly spinning a fiber membrane dry electrode on the skin, which can detect physiological electrical signals, and solves the problem that the preparation process of common dry electrodes is complicated and the adhesion to the skin is poor. , airtight, perspiration and other issues.

technical solutions

In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a method for preparing a fiber membrane dry electrode by spinning directly on the skin, the method comprises the following steps:

(1) The spinning polymer, the conductive material and the solvent are mixed in proportion to form a uniform spinning solution. The spinning polymer and the conductive material can be separately added with a solvent to form a solution and then mixed to obtain the final spinning solution. Directly mix and add solvent to obtain the final spinning solution;

(2) The above-mentioned spinning solution is directly used as a substrate on the skin, and the fiber membrane dry electrode is prepared by spinning on the skin.

In the technical solution of the present invention, the mass ratio of the spinning polymer and the conductive material in the spinning solution is (1:3)-(5:1), and the spinning polymer and the conductive material in the spinning solution The total mass concentration of the material is 1-30%.

In the technical solution of the present invention, the spinning polymer is selected from polyvinyl alcohol (PVA, molecular weight of 10,000-200,000), polyethylene oxide (PEO, molecular weight of 100,000-8 million), polyvinylpyrrolidone ( One or more of PVP, molecular weight of 20,000-1.5 million) and polyvinyl butyral (PVB, molecular weight of 10,000-300,000).

In the technical solution of the present invention, the conductive material is selected from one or more of metal particles, conductive carbon materials, and conductive polymers.

In the technical solution of the present invention, the metal particles include metal nanowires, metal nanoparticles, and metal nanosheets.

In the technical solution of the present invention, the conductive carbon material includes carbon nanotubes (CNT), graphene, carbon black, acetylene black, and carbon fiber.

In the technical solution of the present invention, the conductive polymer includes poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT:PSS), polypyrrole, polyaniline, and polyacetylene.

In the technical solution of the present invention, the solvent is water or ethanol, or a mixture of the two.

In the technical solution of the present invention, the spinning method is selected from one or more combined processes of solution air spinning, electrospinning, and high-speed rotary centrifugal spinning.

In the technical scheme of the present invention, the solution flow rate of the spinning equipment used for spinning is 0.01-10 ml/h, and the spinning distance is 2-30 cm, the spinning time is greater than 1 min, and the specific time needs to be determined according to the material and spinning area.

In the technical scheme of the present invention, for solution air spinning, in addition to the above conditions, the temperature of the spinning air stream is set to not exceed 70 °C; for electrospinning, in addition to the above conditions, the spinning needle and the ground voltage are set to 1-20 kV; For high-speed spin centrifugal spinning, in addition to the above conditions, the spinneret speed was set at 100-5000 rpm.

beneficial effect

Compared with the prior art, the beneficial effects of the present invention are:

1. Using the skin as the substrate, the fiber membrane dry electrode is prepared by spinning directly on the skin, forming in one step, avoiding various preprocessing and transfer steps.

2. The fibrous mesh structure formed on the skin integrates the fibrous structure and the conductive material, which effectively improves the stretchability of the electrode and the fit to the skin, and improves the breathability and perspiration of the electrode.

3. Using water or ethanol, or a mixture of the two as a solvent, avoids the stimulation of organic solvents and the final toxic solvent residues in the preparation process.

Description of drawings

Fig. 1 is the actual picture of the fiber membrane dry electrode prepared by spinning directly on the skin in Example 1.

FIG. 2 is the SEM image of the fiber membrane dry electrode prepared by spinning directly on the skin in Example 1. FIG.

FIG. 3 is the SEM image of the fiber membrane dry electrode prepared by spinning directly on the skin in Example 2. FIG.

FIG. 4 is the SEM image of the fiber membrane dry electrode prepared by spinning directly on the skin in Example 3. FIG.

Embodiments of the present invention

The present invention will be further described in detail below with reference to the examples, but the embodiments of the present invention are not limited thereto.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

The 6 million molecular weight PEO polymer was dissolved and prepared into an aqueous dispersion with a mass fraction of 2%, and then mixed with PEDOT:PSS aqueous solution (mass concentration 1%) according to a mass ratio of 1:1 to form a uniform spinning solution. The mass ratio of polymer and conductive material in the spinning solution was 2:1, and the total mass concentration was 1.5%. Then put the spinning solution into the spray gun of the solution air spinning device (nozzle diameter 0.2mm), the flow rate of the solution air spinning device is 0.4 ml/h, and the flow rate of the solution air spinning device is 100 psi pressure, spinning air temperature 60°C, 10 The receiving distance was cm, the spinning time was 10 min, and the fiber membrane dry electrode was formed by spinning directly on the skin. The actual picture of the electrode prepared by spinning on the skin is shown in Figure 1. It can be seen that the electrode has good adhesion to the skin, can be deformed with the skin compression, and the skin texture is clearly visible. The obtained fiber membrane dry electrode is peeled off from the skin, and the SEM photo obtained by scanning electron microscope is shown in Figure 2. From Figure 2, it can be seen that the fiber membrane dry electrode prepared in Example 1 has a porous structure, which is conducive to ventilation. .

Example 2

The 4 million molecular weight PEO polymer was dissolved into a 3% aqueous dispersion, and then mixed with PEDOT:PSS aqueous solution (mass concentration of 1%) according to the mass ratio of 1:1 to form a uniform spinning solution, and finally spinning The mass ratio of polymer and conductive material in the liquid is 3:1, and the total mass concentration is 2%. Then put the obtained spinning solution into the spray gun of the solution air spinning device (nozzle diameter 0.2mm), the flow rate of the solution air spinning device is 0.6ml/h, and the spinning air pressure is 80 psi, the spinning airflow temperature was 55 °C, the receiving distance was 10 cm, and the spinning time was 15 min, and the fiber membrane dry electrode was formed by spinning directly on the skin. The obtained fiber membrane dry electrode is peeled off from the skin, and the SEM photo obtained by scanning electron microscope is shown in Figure 3. It can be seen from Figure 3 that the fiber membrane dry electrode prepared in Example 2 is relatively fluffy in fiber arrangement.

Example 3

The polyvinyl butyral polymer was dissolved in a mixture of ethanol and water (mass ratio 9:1) to form a 12% solution, and then the hydroxylated carbon nanotubes were dispersed in ethanol to form a 3% dispersion. The two are mixed and stirred at a mass ratio of 1:0.8 to form a uniform spinning solution. The mass ratio of polymer and conductive material in the final spinning solution is 5:1, and the total mass concentration is 8%. Finally, the spinning solution was put into the spray gun of the solution air spinning equipment (nozzle diameter 0.2mm), at a rate of 100 The pressure of psi, the flow rate of the spinning equipment was 0.8 ml/h, the temperature of the spinning air stream was 22 °C, 15 The receiving distance was cm, the spinning time was 8 min, and the fiber membrane dry electrode was formed by spinning directly on the skin. The obtained fiber membrane dry electrode is peeled off from the skin, and the SEM photo obtained by scanning electron microscope is shown in FIG.

To sum up, it can be shown from Figures 1-4 that the method of preparing a fiber membrane dry electrode by spinning directly on the skin provided by the present invention, the fiber network structure formed on the skin, the fiber structure and the conductive material are combined into one, and the remaining The porous air permeability of the fiber electrode effectively improves the stretchability of the electrode and the fit to the skin.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above-mentioned specific embodiments are only specific embodiments of the present invention, and are not intended to limit the protection of the present invention. 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

A method for preparing a fiber membrane dry electrode by spinning directly on the skin, characterized in that the method comprises the following steps:

Mix the spinning polymer, conductive material and solvent in proportion to form a uniform spinning solution;

The above spinning solution was directly used as the substrate to spin the fiber membrane dry electrode on the skin.
The method for directly spinning a fiber membrane dry electrode on the skin according to claim 1, wherein the mass ratio of the spinning polymer and the conductive material in the spinning solution is (1:3)-( 5:1), the total mass concentration of the spinning polymer and the conductive material in the spinning solution is 1-30%.
The method for preparing fiber membrane dry electrodes by spinning directly on the skin according to claim 1, wherein the spinning polymer is selected from the group consisting of polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, polyvinyl butyral One or more of aldehydes.
The method for directly spinning a fiber membrane dry electrode on the skin according to claim 1, wherein the conductive material is selected from one or more of metal particles, conductive carbon materials, and conductive polymers.
The method for directly spinning a fiber membrane dry electrode on the skin according to claim 4, wherein the metal particles comprise metal nanowires, metal nanoparticles, and metal nanosheets.
The method for directly spinning a fiber membrane dry electrode on the skin according to claim 4, wherein the conductive carbon material comprises carbon nanotubes, graphene, carbon black, acetylene black, and carbon fiber.
The method for directly spinning a fiber membrane dry electrode on the skin according to claim 4, wherein the conductive polymer comprises poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) , polypyrrole, polyaniline, polyacetylene.
The method for directly spinning a fiber membrane dry electrode on the skin according to claim 1, wherein the solvent is water or ethanol, or a mixture of the two.
The method for preparing a fiber membrane dry electrode by spinning directly on the skin according to claim 1, wherein the spinning method is selected from the group consisting of solution air spinning, electrospinning, and high-speed rotary centrifugal spinning. Or a variety of combined processes.
The method for directly spinning a fiber membrane dry electrode on the skin according to claim 9, wherein the spinning solution flow rate is 0.01-10 ml/h, and the spinning distance is 2-30 cm, the spinning time is greater than 1 min.