FLEXIBLE WEARABLE DRY ELECTRODE AND PREPARATION METHOD THEREOF

Abstract

The present invention provides a flexible wearable dry electrode and a preparation method thereof. A flexible wearable dry electrode comprises a base fabric, a transfer glue layer and a nano-conductive layer that are successively attached; the formulation of the transfer glue layer is as follows: weighed in weight percentage, 50%-90% of an elastic resin, 5%-15% of a curing agent, and 5%-35% of a filler; the formulation of the nano-conductive layer is as follows: weighed in parts by weight, 0.1-20 parts of a conductive nanomaterial, 0.1-30 parts of a dispersant, and 0.01-5 parts of a binder. The preparation method thereof is as follows: a conductive coating liquid and a transfer glue are prepared respectively, then both are successively transferred to a flexible release film and finally press-fit onto a base fabric, and subsequently, curing is achieved and the release film can then just be torn off.

Claims

1. A flexible wearable dry electrode, comprising a base fabric, a transfer glue layer and a nano-conductive layer, which are successively attached; wherein the transfer glue layer is mainly composed of the following components, by weight percentage: 50%90% of an elastic resin, 5%15% of a curing agent, and 5%35% of a filler; and the nano-conductive layer is mainly composed of the following components, in parts by weight: 0.120 parts of a conductive nanomaterial, 0.130 parts of a dispersant, and 0.015 parts of a binder.

2. The flexible wearable dry electrode according to claim 1, wherein the dispersant is one selected from the group consisting of polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxypropyl methyl cellulose, hexadecyl trimethyl ammonium bromide, sodium laurate, sodium cinnamate, sodium oleate, sodium dodecyl benzenesulfonate, sodium dodecyl sulfonate, carboxymethyl cellulose acetate butyrate, carboxymethyl cellulose, Acacia gum, sodium citrate, styrene-maleic anhydride copolymer, aqueous polyurethane, and aqueous epoxy resin or a mixture of several of the group.

3. The flexible wearable dry electrode according to claim 1, wherein the dispersant is one selected from the group consisting of polyethylene glycol, hydroxypropyl methyl cellulose, polyvinyl alcohol, and sodium laurate or a mixture of several of the group.

4. The flexible wearable dry electrode according to claim 1, wherein the binder is one selected from the group consisting of isocyanate, polyamide, modified aliphatic amine, aromatic polyamine, maleic anhydride, and urea or a mixture of several of the group.

5. The flexible wearable dry electrode according to claim 1, wherein the binder is embodied as isocyanate and/or urea.

6. The flexible wearable dry electrode according to claim 1, wherein the elastic resin is one selected from the group consisting of acrylic resin, polyurethane, modified silica gel resin, and modified epoxy resin or a mixture of several of the group.

7. The flexible wearable dry electrode according to claim 1, wherein the elastic resin is embodied as modified silica gel resin and/or acrylic resin.

8. The flexible wearable dry electrode according to claim 1, wherein the curing agent is one selected from the group consisting of platinum catalyst, amino resin, isocyanate, polyamide, modified aliphatic amine, aromatic polyamine, maleic anhydride, urea, phenolic resin, and dicyanodiamide or a mixture of several of the group.

9. The flexible wearable dry electrode according to claim 1, wherein the curing agent is embodied as platinum catalyst and/or isocyanate.

10. The flexible wearable dry electrode according to claim 1, wherein the filler is one selected from the group consisting of silicon dioxide powder, fumed silicon dioxide powder, titanium dioxide, activated carbon, calcium carbonate, carbon black, -cellulose, mica, zinc oxide, and calcium silicate or a mixture of several of the group.

11. The flexible wearable dry electrode according to claim 1, wherein the filler is embodied as fumed silicon dioxide powder and/or titanium dioxide.

12. The flexible wearable dry electrode according to claim 1, wherein the conductive nanomaterial is one selected from the group consisting of copper nanosheet, copper nanowire, silver nanowire, silver nanosheet, silver nanoparticle, gold nanowire, gold nanosheet, platinum nanowire, palladium nanowire, palladium nanosheet, bismuth nanowire, bismuth nanosheet, nickel nanowire, nickel nanosheet, cobalt nanowire, cobalt nanosheet, gold-silver alloy nanowire, gold-silver alloy nanotube, platinum-silver alloy nanotube, platinum-palladium alloy nanowire, carbon nanotube, carbon nanofiber, graphene, and indium tin oxide nanowire or a mixture of several of the group.

13. The flexible wearable dry electrode according to claim 1, wherein the conductive nanomaterial is one selected from the group consisting of copper nanowire, silver nanowire, carbon nanotube, and graphene or a mixture of several of the group.

14. A method for preparing the flexible wearable dry electrode according to any of claims 1, comprising steps of: adding a solvent to all raw materials for mixing and dissolving according to a formulation of the nano-conductive layer to provide a conductive coating liquid; mixing and dissolving all raw materials according to a formulation of the transfer glue layer to provide a transfer glue; coating a flexible release film with the conductive coating liquid to provide a flexible conductive carrier available for transfer printing; coating a conductive plane side of the flexible conductive carrier with the transfer glue to provide a conductive-glue composite carrier; and press-fitting the conductive-glue composite carrier on the base fabric in a way of exposing the flexible release film to outside, and then heating for curing, and finally tearing off the flexible release film.

15. The method according to claim 14, wherein the press-fitting is achieved by a method of: applying a pressure of 0.001 MPa5 MPa and keeping the pressure for 5300 seconds.

16. The method according to claim 14, wherein heat curing is achieved by a method of: baking at 80300 C. for 5120 minutes.

17. The method according to claim 16, wherein the baking is achieved at a constant temperature.

18. The method according to claim 14, wherein the solvent is one selected from the group consisting of water, ethanol, isopropanol, ethylene glycol, glycerol, isophorone, DBE, dichloroethane, trichloroethane, toluene, xylene, 1,4-dioxane, propylene glycol methyl ether, propylene glycol ethyl ether, carbitol acetate, carbitol caproate, diacetone diacetone alcohol, and diacetone or a mixture of several of the group.

19. The method according to claim 14, wherein the solvent is one selected from the group consisting of water, ethanol, isophorone and ethylene glycol or a mixture of several of the group.

20. The method according to claim 14, wherein the flexible release film is selected from one of polyethylene terephthalate thin film, polycarbonate thin film, polyvinyl chloride thin film, polyethylene thin film, polypropylene thin film, polyurethane thin film, silica gel thin film, polyvinyl alcohol thin film, polytetrafluoroethylene thin film, and polyvinylidene fluoride thin film.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0040] In order to more clearly explain the examples of the present invention or the technical solutions in the prior art, below the drawing to be used in the description of the examples or the prior art will be briefly introduced.

[0041] FIG. 1 is a schematic flow chart for the preparation of a flexible wearable dry electrode provided in example 1 of the present invention.

DETAILED DESCRIPTION

[0042] In the following contents, the embodiments of the present invention will be described in detail with reference to the examples; however, a person skilled in the art would understand that the following examples are merely used to explain the present invention, rather than being deemed as limiting the scope of the present invention. Examples, for which no concrete situations are specified, are performed according to conventional situations or situations recommended by the manufactures. Reagents or instruments, for which no manufacturers are specified, are conventional products available commercially.

Example 1

[0043] A flexible wearable dry electrode:

[0044] Step (1): a nano-conductive coating liquid was firstly prepared, wherein 1 g of copper nanowire, 1 g of silver nanowire and 1 g of graphene were taken and simultaneously dispersed into 25 g of mixed solvent included water, ethanol and ethylene glycol, and then 2 g of polyethylene glycol and 0.5 g of hydroxypropyl methyl cellulose (molecular weight of 20000) were added, and after thorough stirring of and uniform dissolution, 0.2 g of curing agent comprising isocyanate, was added and the solution was continuously stirred till it was completely uniform and then for standby use.

[0045] Step (2): a transfer glue was prepared, wherein 5 g of acrylic ester (Quanzhi Shanghai, type R20B) and 3 g of modified silica gel resin (Shanghai Resin Factory Co., LTD., type 665) were taken and mixed uniformly, then 1.5 g of gas-phased silicon dioxide and 0.5 g of titanium dioxide were added and thoroughly stirred uniformly, and 0.1 g of platinum catalyst and 0.3 g of isocyanate were subsequently added, the obtained substance was continuously stirred uniformly for standby use.

[0046] Step (3): the nano-conductive coating liquid obtained in step (1) was coated onto a PET thin film substrate via a coating machine and with a coating thickness of 150 microns, which leads to a conductive carrier with an attached nano-conductive layer, the surface resistance of the conductive carrier was 200 m/.

[0047] Step (4): the transfer glue obtained in step (2) was coated on the conductive plane of the conductive carrier obtained in step (3) with a coating thickness of 200 microns, which leads to a conductive-glue composite carrier.

[0048] Step (5): the glue plane of the conductive-glue composite carrier obtained in step (4) was attached to the fabric, and the two were press-fit for 30 seconds with a pressure of 0.5 MPa, and the product was subsequently placed in a dry oven at a temperature of 150 C. for baking for 20 minutes. After the baking, the product was taken out and the PET substrate was torn off, which leads to a fabric-based flexible electrode.

[0049] The flow path of the above-mentioned preparation method is shown in FIG. 1.

[0050] Performance test: The surface resistance of the electrode was 200 m/. The resulting flexible electrode also showed flexibility and elasticity that completely match ordinary clothes and could realize a relatively good contact with human skin, and no variation on the electrode resistance occurred after soaking in a 5% sodium chloride aqueous solution having a pH value of 8.5 for 60 minutes; after being insolated under the sunlight for 8 hours, the electrode resistance did not change, and no variation occurred regarding the physical properties thereof; there was no electrode deformation and no resistance variation after steam ironing at 200 C. for 30 minutes; the product could be placed under a temperature of 100 C. and a humidity of 90% for over 12 months without any variation; washing for 10 hours at a water temperature of 60 C. with various types of detergents caused no variation in electrode structure and in electrode resistance; and there was no variation in the electrode conductivity and in the electrode appearance after relative rubbing of the conductive planes for 200 times. The content mentioned above shows that the flexible electrode prepared via the coating-transfer mode has good functional characteristics.

Example 2

[0051] A flexible wearable dry electrode:

[0052] Step (1): a nano-conductive coating liquid was firstly prepared, wherein 2 g of silver nanowire, 1 g of carbon nanotube and 1 g of graphene were taken and simultaneously dispersed into 30 g of mixed solvent containing water, ethylene glycol and isophorone, and then 1 g of polyvinyl alcohol (molecular weight of 40000), 0.5 g of hydroxypropyl methyl cellulose (molecular weight of 400) and 1 g of sodium laurate were added, and after thorough stirring and uniform dissolution, curing agents comprising 0.2 g of isocyanate and 0.1 g of urea, were added and the solution was continuously stirred till it was completely uniform and then for standby use.

[0053] Step (2): a transfer glue was prepared, wherein 20 g of modified silica gel resin (Shanghai Resin Factory Co., LTD., type 665) was taken and mixed uniformly, then 1 g of gas-phased silicon dioxide and 1.5 g of titanium dioxide were added and thoroughly stirred uniformly, and 0.5 g of platinum catalyst and 1 g of isocyanate were subsequently added, the obtained substance was continuously stirred uniformly for standby use.

[0054] Step (3): the nano-conductive coating liquid obtained in step (1) was coated onto a PC thin film substrate via a coating machine and with a coating thickness of 120 microns, which leads to a conductive carrier with an attached nano-conductive layer, the surface resistance of the conductive carrier was 80 m/.

[0055] Step (4): the transfer glue obtained in step (2) was coated on the conductive plane of the conductive carrier obtained in step (3) with a coating thickness of 250 microns, which leads to a conductive-glue composite carrier.

[0056] Step (5): the glue plane of the conductive-glue composite carrier obtained in step (4) was attached to the fabric, and the two were press-fit for 60 seconds with a pressure of 0.8 MPa, and the product was subsequently placed in a dry oven at a temperature of 80 C. for baking for 100 minutes. After the baking, the product was taken out and the PC substrate was torn off, which leads to a fabric-based flexible electrode.

[0057] Performance test: The surface resistance of the electrode was still 80 m/, and the conductive characteristics of the original conductive carrier were effectively maintained. The resulting flexible electrode also showed flexibility and elasticity that completely match ordinary clothes and could realize a relatively good contact with human skin, and no variation on the electrode resistance occurred after soaking in a 8% sodium chloride aqueous solution having a pH value of 7.5 for 80 minutes; after being insolated under the sunlight for 24 hours, the electrode resistance did not change, and no variation occurred regarding the physical properties thereof; there was no electrode deformation and no resistance variation after steam ironing at 180 C. for 60 minutes; the product could be placed under a temperature of 180 C. and a humidity of 80% for 15 months without any variation; washing for 24 hours at a water temperature of 80 C. with various types of detergents caused no variation in electrode structure and in electrode resistance; and there was no variation in the electrode conductivity and in the electrode appearance after relative rubbing of the conductive planes for 300 times. The content mentioned above shows that the flexible electrode prepared via the coating-transfer mode has good functional characteristics.

Example 3

[0058] A flexible wearable dry electrode:

[0059] Step (1): a nano-conductive coating liquid was firstly prepared, wherein 0.05 g of copper nanowire, 0.1 g of silver nanowire and 0.2 g of graphene were taken and simultaneously dispersed into 300 g of mixed solvent containing water, ethylene glycol and glycerol, and then 0.1 g of polyvinyl alcohol (molecular weight of 20000), 0.15 g of hydroxypropyl methyl cellulose (molecular weight of 40000) and 0.1 g of sodium laurate were added, and after thorough stirring and uniform dissolution, binder comprising 0.02 g of isocyanate and 0.02 g of urea, were added and the solution was continuously stirred till it was completely uniform and then for standby use.

[0060] Step (2): a transfer glue was prepared, wherein 45 g of modified silica gel resin (Shanghai Resin Factory Co., LTD., type 665) was taken and mixed uniformly, then 1 g of gas-phased silicon dioxide and 1.5 g of titanium dioxide were added and thoroughly stirred uniformly, and 2.5 g of platinum catalyst was subsequently added, the obtained substance was continuously stirred uniformly for standby use.

[0061] Step (3): the nano-conductive coating liquid obtained in step (1) was coated onto a PC thin film substrate via a coating machine and with a coating thickness of 25 microns, which leads to a conductive carrier with an attached nano-conductive layer, the surface resistance of the conductive carrier was 50 m/.

[0062] Step (4): the transfer glue obtained in step (2) was coated on the conductive plane of the conductive carrier obtained in step (3) with a coating thickness of 800 microns, which leads to a conductive-glue composite carrier.

[0063] Step (5): the glue plane of the conductive-glue composite carrier obtained in step (4) was attached to the fabric, and the two were press-fit for 300 seconds with a pressure of 5 MPa, and the product was subsequently placed in a dry oven at a temperature of 80 C. for baking for 120 minutes. After the baking, the product was taken out and the PC substrate was torn off, which leads to a fabric-based flexible electrode. Wherein the surface resistance of the electrode was still 50 m/, and the conductive characteristics of the original conductive carrier were effectively maintained. The resulting flexible electrode also showed flexibility and elasticity that completely match ordinary clothes and could realize a relatively good contact with human skin, and no variation on the electrode resistance occurred after soaking in a 0.1% sodium chloride aqueous solution having a pH value of 6 for 120 minutes; after being insolated under the sunlight for 48 hours, the electrode resistance did not change, and no variation occurred regarding the physical properties thereof; there was no electrode deformation and no resistance variation after steam ironing at 200 C. for 120 minutes; the product could be placed under a temperature of 200 C. and a humidity of 100% for 24 months without any variation; washing for 48 hours at a water temperature of 0 C. with various types of detergents caused no variation in electrode structure and in electrode resistance; and there was no variation in the electrode conductivity and in the electrode appearance after relative rubbing of the conductive planes for 400 times. The content mentioned above shows that the flexible electrode prepared via the coating-transfer mode has good functional characteristics.

Example 4

[0064] A flexible wearable dry electrode:

[0065] Step (1): a nano-conductive coating liquid was firstly prepared, wherein 2 g of copper nanowire, 6 g of silver nanowire and 2 g of carbon nanotube were taken and simultaneously dispersed into 22.5 g of mixed solvent containing water, ethanol and glycerol, and then 10 g of polyvinyl alcohol (molecular weight of 40000), 2.5 g of carboxymethyl cellulose acetate butyrate (CMCAB-641-0.2) and 2.5 g of sodium cinnamate were added, and after thorough stirring and uniform dissolution, binder comprising 1.25 g of isocyanate and 1.25 g of urea, were added and the solution was continuously stirred till it was completely uniform and then for standby use.

[0066] Step (2): a transfer glue was prepared, wherein 25 g of modified silica gel resin (Shanghai Resin Factory Co., LTD., type 665) was taken and mixed uniformly, then 17.5 g of titanium dioxide was added and thoroughly stirred uniformly, and 7.5 g of platinum catalyst was subsequently added, the obtained substance was continuously stirred uniformly for standby use.

[0067] Step (3): the nano-conductive coating liquid obtained in step (1) was coated onto a PET thin film substrate via a coating machine and with a coating thickness of 350 microns, which leads to a conductive carrier with an attached nano-conductive layer, the surface resistance of the conductive carrier was 0.01 m/.

[0068] Step (4): the transfer glue obtained in step (2) was coated on the conductive plane of the conductive carrier obtained in step (3) with a coating thickness of 1000 microns, which leads to a conductive-glue composite carrier.

[0069] Step (5): the glue plane of the conductive-glue composite carrier obtained in step (4) was attached to the fabric, and the two were press-fit for 5 seconds with a pressure of 0.001 MPa, and the product was subsequently placed in a dry oven at a temperature of 300 C. for baking for 5 minutes. After the baking, the product was taken out and the PC substrate was torn off, which leads to a fabric-based flexible electrode. Wherein the surface resistance of the electrode was still 0.01 m/, and the conductive characteristics of the original conductive carrier were effectively maintained. The resulting flexible electrode also showed flexibility and elasticity that completely match ordinary clothes and could realize a relatively good contact with human skin, and no variation on the electrode resistance occurred after soaking in a 10% sodium chloride aqueous solution having a pH value of 9 for 300 minutes; after being insolated under the sunlight for 24 hours, the electrode resistance did not change, and no variation occurred regarding the physical properties thereof; there was no electrode deformation and no resistance variation after steam ironing at 100 C. for 10 minutes; the product could be placed under a temperature of 100 C. and a humidity of 20% for 24 months without any variation; washing for 12 hours at a water temperature of 80 C. with various types of detergents caused no variation in electrode structure and in electrode resistance; and there was no variation in the electrode conductivity and in the electrode appearance after relative rubbing of the conductive planes for 200 times. The content mentioned above shows that the flexible electrode prepared via the coating-transfer mode has good functional characteristics.

Comparative Example

[0070] A traditional flexible electrode, prepared in the following mode: after the mixture of conductive carbon powders with a silicone rubber or a polyurethane resin, the obtained mixture was shaped by pouring into a mold and the heat curing.

[0071] Performance test: The surface resistance of the electrode was 500 m/; as the conductive material was mixed with a resin and a relatively good flexibility had to be maintained, the original conductive characteristics of the conductive material could not be maintained; due to the natural incompatibility of the conductive carbon powders with the resin material that is mixed therewith, so that the resulting flexible electrode could not be totally matched to the flexibility and elasticity of ordinary clothing fabrics, and the contact of the flexible electrode with the human skin was just acceptable, however, the contact impedance was great; no variation on the electrode resistance occurred after soaking in a 0.1% sodium chloride aqueous solution having a pH value of 6 for 60 minutes; after being insolated under the sunlight for 8 hours, the electrode hardened and the resistance increased; after steam ironing at 100 C. for 10 minutes, the electrode deformed while no significant variation in resistance occurred; the electrode deformed and was embrittled, and the resistance increased exponentially after placement under a temperature of 100 C. and a humidity of 90% for 12 months; after washing for 10 hours at a water temperature of 60 C. with various types of detergents, the electrode was broken, while no significant variation in resistance occurred; and no significant variation in the electrode conductivity occurred, and the electrode appearance was significantly roughened after relative rubbing of the conductive planes for 200 times. The content mentioned above shows that the functional characteristics of the traditional flexible electrode are relatively poor.

[0072] Although the present invention has already been explained and described through specific examples, it shall be aware that many further modifications and variations may also be made without departing from the spirit and scope of the present invention. Thus, it means that all these modifications and variations falling in the scope of the present invention are included in the appended claims.