Elastic dry electrode, preparation method and application thereof

Abstract

The application provides an elastic dry electrode and a preparation method and application thereof, and the preparation method comprises the following steps: adding a polymer material into a solvent to prepare a first solution; adding a poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution and metal nanomaterials into the first solution, stirring, and then adding a conductive additive to obtain a second solution; and immersing an elastic porous substrate into the second solution, and then performing vacuumizing treatment to obtain the elastic dry electrode. According to the preparation method, the elastic porous substrate has a porous skeleton structure, the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and the metal nanomaterials are used as conductive components, the physical adsorption of the elastic porous substrate to the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and the action of the polymer material are utilized, and the elastic dry electrode can be prepared after vacuumizing treatment. The prepared elastic dry electrode does not need skin preparation and does not need to use conductive gel, has good biocompatibility, can effectively avoid the influence of hair, and improves comfort.

Description

Technical Field

[0001] This invention relates to the field of electrode preparation technology, and in particular to an elastic dry electrode, its preparation method, and its application. Background Technology

[0002] Brain-computer interfaces (BCIs) enable communication between the brain and electronic devices. One of the biggest challenges is developing an effective, non-invasive EEG electrode that minimizes the impact of hair on the skin while avoiding the inconvenience and complications associated with conductive gels. Currently, commercially available Ag / AgCl gel electrodes are widely used in BCI applications. However, Ag / AgCl gel electrodes require time-consuming preparation processes such as hair trimming, cleaning, and electrolysis of the gel coating. After prolonged use, the conductive gel may dehydrate and coagulate, leading to a decrease in signal quality. Furthermore, the gel has been observed to potentially cause allergic reactions or skin irritation in patients. Cleaning of the conductive gel after testing is also necessary, causing inconvenience for the test subject. The rigidity of the overall electrode system material also significantly impacts measurement comfort.

[0003] Given the current limitations of Ag / AgCl gel electrodes in brain-computer interfaces, it is necessary to improve them. Summary of the Invention

[0004] In view of this, the present invention proposes an elastic dry electrode, its preparation method and application, which solves or at least partially solves the technical defects existing in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing an elastic dry electrode, comprising the following steps:

[0007] A polymer material is added to a solvent to prepare a first solution;

[0008] A poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution and metal nanomaterials were added to the first solution. After stirring, a conductive additive was added, and stirring was continued to obtain the second solution.

[0009] The elastic porous substrate is immersed in the second solution and then subjected to vacuum treatment to obtain the elastic dry electrode.

[0010] Preferably, in the method for preparing the elastic dry electrode, the polymer material includes any one of polyvinyl butyral and polyvinyl alcohol;

[0011] The solvent includes alcohol or water.

[0012] Preferably, in the method for preparing the elastic dry electrode, the conductive additive includes at least one of ethylene glycol and dimethyl sulfoxide.

[0013] Preferably, in the method for preparing the elastic dry electrode, when the polymer material is polyvinyl butyral, the solvent is ethanol; when the polymer material is polyvinyl alcohol, the solvent is water.

[0014] Preferably, in the method for preparing the elastic dry electrode, the elastic porous substrate includes any one of a polymer flexible porous substrate and an elastic porous sponge substrate.

[0015] Preferably, in the method for preparing the elastic dry electrode, the flexible porous polymer substrate includes a porous PDMS substrate;

[0016] The elastic porous sponge substrate includes any one of melamine sponge and polyurethane sponge.

[0017] The method for preparing the porous PDMS substrate includes the following steps:

[0018] The first mixture is obtained by mixing the PDMS prepolymer and the curing agent;

[0019] The first mixture was mixed with hexane and stirred to obtain the second mixture;

[0020] Add water to the second mixture and stir to obtain the third mixture;

[0021] The third mixture is then heated and polymerized at 25–150°C to obtain a porous PDMS substrate.

[0022] Preferably, in the method for preparing the elastic dry electrode, polyvinyl butyral is added to ethanol and stirred at 60-120°C for 30-180 min to obtain a first solution; wherein, the concentration of polyvinyl butyral added to ethanol is 0.001-0.2 g / mL.

[0023] Preferably, in the method for preparing the elastic dry electrode, the mass fraction of the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution is 5-70%.

[0024] The mass ratio of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid to conductive additives is 4:(0.1~5);

[0025] The vacuuming process takes 5 to 180 minutes.

[0026] The metal nanomaterials include at least one of silver nanowires, platinum nanowires, platinum nanorods, MXene, silver nanoparticles, gold nanoparticles, and gold nanowires.

[0027] If the metal nanomaterial is silver nanowire, the concentration of the silver nanowire is 1–100 mg / mL.

[0028] Secondly, the present invention also provides an elastic dry electrode, which is prepared by the aforementioned preparation method.

[0029] Thirdly, the present invention also provides an application of the aforementioned elastic dry electrode as an electroencephalogram (EEG) electrode.

[0030] The preparation method of the elastic dry electrode of the present invention has the following advantages over the prior art: (1) In the preparation method of the elastic dry electrode of the present invention, the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution is an aqueous solution of a high molecular polymer with high conductivity; the elastic porous substrate has a porous framework structure as an elastic substrate, the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and metal nanomaterials are conductive components, and the polymer material in the first solution can increase the adhesion between the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and the elastic sponge; by utilizing the physical adsorption of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid by the elastic sponge and the role of the polymer material, the elastic dry electrode can be prepared by vacuum treatment. The prepared elastic dry electrode does not require skin preparation, does not require the use of conductive gel, has good biocompatibility, and can effectively avoid the influence of hair and improve comfort; the elastic dry electrode of the present invention can be used as an EEG electrode for detecting EEG signals. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic flowchart of the preparation method of the elastic dry electrode of the present invention;

[0033] Figure 2 This is a schematic diagram of the preparation process of the elastic dry electrode of the present invention. Detailed Implementation

[0034] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present application.

[0035] This application provides a method for preparing an elastic dry electrode, such as... Figure 1 As shown, it includes the following steps:

[0036] S1. Add the polymer material to the solvent to prepare the first solution;

[0037] S2. Add the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution and the metal nanomaterial to the first solution, stir, then add the conductive additive, and continue stirring to obtain the second solution;

[0038] S3. Immerse the elastic porous substrate in the second solution, stir and mix thoroughly, and then perform vacuum treatment to obtain the elastic dry electrode.

[0039] It should be noted that the method for preparing the elastic dry electrode provided in this application embodiment uses poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution (PEDOT:PSS), which is an aqueous solution of a high molecular weight polymer with high conductivity. The elastic porous substrate has a porous framework structure, and the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and metal nanomaterials serve as conductive components. The polymer material in the first solution can increase the adhesion between the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and the elastic sponge. By utilizing the physical adsorption of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid by the elastic sponge and the effect of the polymer material, the elastic dry electrode can be prepared after vacuum treatment. The prepared elastic dry electrode does not require skin preparation or the use of conductive gel, has good biocompatibility, and can effectively avoid the influence of hair, thus improving comfort.

[0040] In some embodiments, the polymeric material includes, but is not limited to, any one of polyvinyl butyral and polyvinyl alcohol;

[0041] Solvents include alcohol solvents or water.

[0042] Using polymers such as polyvinyl butyral and polyvinyl alcohol can greatly improve the adhesion of elastic sponge to poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid. Specifically, alcohol solvents such as methanol, ethanol, propanol, butanol, isobutanol, diacetone alcohol, ketols, and benzyl alcohol can be used.

[0043] If polyvinyl alcohol is used as the polymer material, water is used as the solvent.

[0044] In some embodiments, the conductive additive includes at least one of ethylene glycol and dimethyl sulfoxide.

[0045] It is understandable that the conductivity of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution can be improved by adding conductive additives such as ethylene glycol and dimethyl sulfoxide.

[0046] In some embodiments, the polymer material is polyvinyl butyral ester, and the solvent is ethanol.

[0047] In some embodiments, the polymer material is polyvinyl alcohol and the solvent is water.

[0048] In some embodiments, the elastic porous substrate includes any one of a polymer flexible porous substrate and an elastic porous sponge substrate.

[0049] In some embodiments, the flexible porous polymer substrate includes a porous PDMS substrate;

[0050] The elastic porous sponge substrate includes either melamine sponge or polyurethane sponge.

[0051] The method for preparing the porous PDMS substrate includes the following steps:

[0052] A1. The first mixture is obtained by mixing PDMS prepolymer and curing agent;

[0053] A2. Mix the first mixture with hexane and stir to obtain the second mixture;

[0054] A3. Add water to the second mixture and stir to obtain the third mixture;

[0055] A4. The third mixture is then heated and polymerized at 25–150°C to obtain a porous PDMS substrate.

[0056] Specifically, PDMS prepolymer and curing agent are mixed at a mass ratio of 10:1 to obtain a first mixture; the first mixture and hexane are then mixed at a mass ratio of 2:8 and stirred vigorously for 10 minutes to obtain a second mixture; ultrapure water is added dropwise to the second mixture and stirred thoroughly for 30 minutes to obtain a third mixture in the form of a viscous liquid, wherein the mass ratio of the second mixture to the added ultrapure water is 2:1; the third mixture is then heated and polymerized at 120°C to obtain a porous PDMS substrate.

[0057] Specifically, melamine sponges have excellent water absorption and retention, high specific strength, stable chemical properties, and strong anti-aging properties, and can be soaked for a long time without deformation or aging.

[0058] In some embodiments, polyvinyl butyral is added to ethanol and stirred at 60–120°C for 30–180 min to obtain a first solution; wherein, the concentration of polyvinyl butyral is 0.001–0.2 g / mL when polyvinyl butyral is added to ethanol.

[0059] In some embodiments, the mass fraction of the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution is 5-70%;

[0060] The mass ratio of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution to conductive additive is 4:(0.1~5).

[0061] The vacuuming process takes 5 to 180 minutes.

[0062] Metal nanomaterials include, but are not limited to, at least one of silver nanowires, platinum nanowires, platinum nanorods, MXene, silver nanoparticles, gold nanoparticles, and gold nanowires; if silver nanowires are used as the metal nanomaterials, the concentration of the silver nanowires is 1 to 100 mg / mL.

[0063] Obviously, the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution and the metal nanomaterials have different mass concentrations and different electrical conductivity.

[0064] In some embodiments, before immersing the elastic porous substrate in the second solution, the elastic porous substrate is further cleaned in an ultrasonic bath with acetone, ethanol and deionized water in sequence, each cleaning process lasting 10 to 20 minutes, followed by ventilation and drying.

[0065] In some embodiments, after immersing the elastic porous substrate in the second solution, the elastic sponge impregnated with the mixture is further subjected to vacuum treatment to remove excess mixture, thereby ensuring that the conductive mixture is uniformly coated on the elastic sponge. Specifically, refer to... Figure 2 As shown, Figure 2 A schematic diagram of the preparation process of the flexible dry electrode is shown, where PVB represents polyvinyl butyral and EG represents ethylene glycol.

[0066] Based on the same inventive concept, embodiments of this application also provide the application of the above-prepared elastic dry electrode as an EEG electrode. Specifically, the elastic dry electrode of this application can be used to detect EEG signals.

[0067] The following specific embodiments further illustrate the preparation method of the elastic dry electrode of this application.

[0068] Example 1

[0069] This application provides a method for preparing an elastic dry electrode, comprising the following steps:

[0070] S1. Add 0.2g of polyvinyl butyral (PVB) to 20mL of ethanol, and then stir at 80℃ for 40min to completely dissolve the PVB and prepare the first solution.

[0071] S2. A 40% (w / w) poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution and 5 mg / mL silver nanowires were added to the first solution. The mixture was stirred at 25°C for 30 min, and then ethylene glycol was added. The stirring was continued for another 30 min to obtain the second solution. The mass ratio of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid to ethylene glycol in the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution was 4:1.

[0072] S3. Clean the 10cm cube of melamine sponge sequentially with acetone, ethanol and deionized ultrasonic cleaner, each step for 10 minutes, and then dry.

[0073] S4. Immerse the dried melamine sponge in the second solution, and then vacuum the melamine sponge soaked in the mixture to obtain the elastic dry electrode.

[0074] Example 2

[0075] This application provides a method for preparing an elastic dry electrode, comprising the following steps:

[0076] S1. Add 0.3g of polyvinyl butyral (PVB) to 20mL of ethanol, and then stir at 70℃ for 60min to completely dissolve the PVB and prepare the first solution.

[0077] S2. A 5% (w / w) poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution and 10 mg / mL silver nanowires were added to the first solution, and the mixture was stirred at 25°C for 45 min. Then, ethylene glycol was added, and the mixture was stirred for another 45 min to obtain the second solution. The mass ratio of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid to ethylene glycol in the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution was 4:0.5.

[0078] S3. Clean the 10cm cube of melamine sponge sequentially with acetone, ethanol and deionized ultrasonic cleaner, each step for 10 minutes, and then dry.

[0079] S4. Immerse the dried melamine sponge in the second solution, and then vacuum the melamine sponge soaked in the mixture to obtain the elastic dry electrode.

[0080] Example 3

[0081] This application provides a method for preparing an elastic dry electrode, comprising the following steps:

[0082] S1. Add 0.4g of polyvinyl butyral (PVB) to 20mL of ethanol, and then stir at 90℃ for 30min to completely dissolve the PVB and prepare the first solution.

[0083] S2. A 70% (w / w) poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution and 1 mg / mL silver nanowires were added to the first solution, and the mixture was stirred at 25°C for 60 min. Then, ethylene glycol was added, and the mixture was stirred for another 60 min to obtain the second solution. The mass ratio of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid to ethylene glycol in the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution was 4:2.

[0084] S3. Clean the 10cm cube of melamine sponge sequentially with acetone, ethanol and deionized ultrasonic cleaner, each step for 10 minutes, and then dry.

[0085] S4. Immerse the dried melamine sponge in the second solution, and then vacuum the melamine sponge soaked in the mixture to obtain the elastic dry electrode.

[0086] Example 4

[0087] This application provides a method for preparing an elastic dry electrode, comprising the following steps:

[0088] S1. Prepare an aqueous solution with a polyvinyl alcohol content of 30% to obtain the first solution;

[0089] S2. Add a 40% (w / w) poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution and 5 mg / mL silver nanowires to the first solution, and stir at 25°C for 30 min to obtain the second solution.

[0090] S3. Clean the 10cm cube of melamine sponge sequentially with acetone, ethanol and deionized ultrasonic cleaner, each step for 10 minutes, and then dry.

[0091] S4. Immerse the dried melamine sponge in the second solution, and then vacuum the melamine sponge soaked in the mixture to obtain the elastic dry electrode.

[0092] The above description is only a partial embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for preparing an elastic dry electrode, characterized in that, Includes the following steps: A polymer material is added to a solvent to prepare a first solution; A poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution and metal nanomaterials were added to the first solution. After stirring, a conductive additive was added, and stirring was continued to obtain the second solution. The elastic porous substrate is immersed in the second solution and then subjected to vacuum treatment to obtain the elastic dry electrode; the polymer material includes any one of polyvinyl butyral and polyvinyl alcohol. The solvent includes alcohol or water; The elastic porous substrate includes any one of a polymer flexible porous substrate and an elastic porous sponge substrate. The poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution and the metal nanomaterials have different mass concentrations and different electrical conductivity.

2. The method for preparing the elastic dry electrode as described in claim 1, characterized in that, The polymeric material includes any one of polyvinyl butyral and polyvinyl alcohol. The solvent includes alcohol or water.

3. The method for preparing the elastic dry electrode as described in claim 1, characterized in that, The conductive additive includes at least one of ethylene glycol and dimethyl sulfoxide.

4. The method for preparing the elastic dry electrode as described in claim 1, characterized in that, The polymer flexible porous substrate includes a porous PDMS substrate; The elastic porous sponge substrate includes any one of melamine sponge and polyurethane sponge. The method for preparing the porous PDMS substrate includes the following steps: The first mixture is obtained by mixing the PDMS prepolymer and the curing agent; The first mixture was mixed with hexane and stirred to obtain the second mixture; Add water to the second mixture and stir to obtain the third mixture; The third mixture is then heated and polymerized at 25~150℃ to obtain a porous PDMS substrate.

5. The method for preparing the elastic dry electrode as described in claim 1, characterized in that, Polyvinyl butyral ester was added to ethanol and stirred at 60~120℃ for 30~180 min to obtain the first solution; wherein, the concentration of polyvinyl butyral ester added to ethanol was 0.001~0.2 g / mL.

6. The method for preparing the elastic dry electrode according to claim 1, characterized in that, The mass fraction of the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid solution is 5-70%. The mass ratio of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid to conductive additives is 4:(0.1~5); The vacuuming process takes 5 to 180 minutes. The metal nanomaterials include at least one of silver nanowires, platinum nanowires, platinum nanorods, MXene, silver nanoparticles, gold nanoparticles, and gold nanowires. If the metal nanomaterial is silver nanowire, the concentration of the silver nanowire is 1~100 mg / mL.

7. A flexible dry electrode, characterized in that, It is prepared by any one of the preparation methods described in claims 1 to 6.

8. The application of the elastic dry electrode as described in claim 7 as an EEG electrode.

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