Electrode and method for making the same

Abstract

The present invention discloses an electrode and a method for making the same. The electrode comprises: an active conductive material layer for transmitting a bioelectric signal collected by a flexible conductive layer from a diseased part; a flexible conductive layer arranged on a first surface of the active conductive material layer; a first magnetic component arranged in the flexible conductive layer, the first magnetic component being used to mutually adsorb with a second magnetic component fixed inside the diseased part to fix the electrode. The electrode has excellent biocompatibility and stretchability, ensures fit and comfort, can reduce interference caused by limb movement or muscle tremor of the user, makes the collected bioelectric signal relatively stable, and is immune to motion artifacts.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to an electrode and a manufacturing method thereof. Background Art

[0002] The nerve cells in the cerebral cortex discharge spontaneously and continuously, and the electrical signals are superimposed in time and space to form EEG signals on the scalp. EEG signals can effectively reflect the current state of brain activity and provide strong evidence for clinical diagnosis, scientific research or cognitive function assessment. Electrodes are placed on the surface of the scalp to measure EEG signals. However, the outermost layer of the scalp is the stratum corneum, which is composed of dead cells and has high impedance, making the measured EEG signal-to-noise ratio low. In addition, the hair blocks the electrodes from directly contacting the scalp, further affecting the quality of the EEG signal. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the defect of low signal-to-noise ratio of bioelectric signals collected by electrodes for collecting bioelectric signals such as brain waves in the prior art, and to provide an electrode and a method for making the same.

[0004] The present invention solves the above technical problems through the following technical solutions:

[0005] In a first aspect, an electrode is provided, comprising:

[0006] The active conductive material layer is used to transmit the bioelectrical signals collected by the flexible conductive layer at the diseased part;

[0007] The flexible conductive layer is disposed on the first surface of the active conductive material layer;

[0008] The first magnetic attraction component is arranged in the flexible conductive layer, and is used to be mutually adsorbed with the second magnetic attraction component fixed inside the diseased part to fix the electrode.

[0009] Optionally, the electrode further comprises:

[0010] A plurality of probes are disposed on the flexible conductive layer and located at a surface away from the active conductive material layer.

[0011] Optionally, an electrode port is provided on the active conductive material layer, and the electrode port is used to connect to an external device and output the bioelectric signal to the external device.

[0012] Optionally, the material of the flexible conductive layer includes polydimethylsiloxane and particle-shaped carbon black.

[0013] Optionally, the active conductive material layer comprises graphene and silver nanowires.

[0014] In a second aspect, a method for manufacturing an electrode is provided, for manufacturing the electrode described in any one of the above items; the manufacturing method comprises:

[0015] Dispersing a polydimethylsiloxane solution on the first film and adding carbon black in particle form to form a flexible conductive layer;

[0016] Implanting a first magnetic attraction component in the flexible conductive layer;

[0017] Drop coating a graphene solution on the surface of a solid substrate to obtain a graphene layer;

[0018] spraying silver nanowires on the surface of the graphene layer to obtain an active conductive material layer;

[0019] A flexible conductive layer implanted with the first magnetic attraction component is deposited on the first surface of the active conductive material layer.

[0020] Optionally, it also includes:

[0021] Silver and silver chloride mixed in a preset ratio are made into a probe, and the probe is fixed on a surface of the flexible conductive layer.

[0022] Optionally, the polydimethylsiloxane solution includes a polydimethylsiloxane main agent and a curing agent, and the mass ratio of the polydimethylsiloxane main agent to the curing agent is 10:1.

[0023] Optionally, spraying silver nanowires on the surface of the graphene layer to obtain the active conductive material layer comprises:

[0024] Spraying silver nanowires on the surface of the graphene layer so that the silver nanowires are adsorbed on the surface of the graphene layer to form a conductive network;

[0025] The active conductive material layer is obtained by oxidizing and reducing the graphene layer adsorbed with the silver nanowires.

[0026] Optionally, it also includes:

[0027] An electrode port is drawn out from the surface of the active conductive material layer.

[0028] The positive progressive effect of the present invention is that the electrode provided by the embodiment of the present invention has good biocompatibility and stretchability, ensures fit and comfort, can reduce the interference caused by the user's limb movement or muscle tremor, makes the collected bioelectric signals relatively stable, and is immune to motion artifacts. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1a A schematic diagram of the structure of an electrode provided by an exemplary embodiment of the present invention;

[0030] Figure 1b A schematic diagram of the structure of another electrode provided by an exemplary embodiment of the present invention;

[0031] Figure 2 A flowchart of a method for manufacturing an electrode provided by an exemplary embodiment of the present invention;

[0032] Figure 3 A flow chart of another method for manufacturing an electrode provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0034] Figure 1a FIG1 is a schematic diagram of the structure of an electrode provided by an exemplary embodiment of the present invention. The electrode includes: an active conductive material layer 11 , a flexible conductive layer 12 , a first magnetic attraction component 13 and a second magnetic attraction component 14 .

[0035] The active conductive material layer 11 is used to transmit the bioelectrical signals collected by the flexible conductive layer 12 at the diseased part.

[0036] The active conductive material layer includes graphene and silver nanowires, which is a composite conductive material. Graphene is a single layer of carbon atoms in the form of sp 2 The new material with a hexagonal structure composed of hybrid orbitals is the material with the lowest resistivity and the best conductivity found so far due to its special structure. In addition to its excellent conductivity, graphene also has the advantages of high transparency, high mechanical strength, good tensile properties and good adhesion to polydimethylsiloxane, so graphene is selected as one of the materials for the active conductive material layer. Silver nanowires (AgNWs) combine the excellent conductivity characteristics of silver and the size effect of nanowires, and the network they form has excellent flexibility, which can make the electrode adapt to larger deformations, so silver nanowires are selected as one of the materials for the active conductive material layer.

[0037] The flexible conductive layer 12 is disposed on the first surface of the active conductive material layer.

[0038] The material of the flexible conductive layer includes polydimethylsiloxane and particle-shaped carbon black. Polydimethylsiloxane (PDMS) has advantages in biocompatibility, waterproofness, stability in a wide temperature range, transparency, elasticity and high stretchability, and is easy to combine with active conductive materials to fix it on its surface. Therefore, highly biocompatible polydimethylsiloxane is selected as the substrate of the flexible conductive layer so that the electrode can be closely connected to the skin epidermis. By adding appropriate particle-shaped carbon black as a filler to the substrate of the flexible conductive layer, it is made conductive to form a conductive rubber (flexible conductive layer). The particle-shaped carbon black is used as a suitable filler for conductive rubber, which is cheap and has good conductivity. At the same time, it can increase the tensile strength and tear resistance of the rubber. The flexible conductive layer allows the electrode to stably record bioelectric signals for a long time, and is less disturbed by the user's limb movement or muscle tremor.

[0039] The first magnetic attraction component 13 is disposed in the flexible conductive layer and is used to be mutually attracted with the second magnetic attraction component 14 fixed inside the affected part to fix the electrode, so as to facilitate the collection and recording of bioelectric signals.

[0040] It should be noted that the number of the first magnetic components is not limited to Figure 1a The one shown may be two, three or even more, dispersedly arranged in the flexible conductive layer. The second magnetic component 14 is wrapped with a ceramic material with good biocompatibility, which can protect the tissue of the affected area from the risk of infection.

[0041] In one embodiment, an electrode port is provided on the active conductive material layer, and the electrode port is used to connect to an external device and output the bioelectric signal collected by the active conductive material layer to the external device.

[0042] Before collecting bioelectric signals, the second magnetic component 14 needs to be implanted inside the diseased part. Taking the brain as an example, the second magnetic component (for example, a fixing needle) is fixed on the skull 22, and the electrode is set on the biological tissue 21 (including the epidermis, dermis, and subcutaneous tissue). The first magnetic component 13 and the second magnetic component 14 are mutually adsorbed to achieve the purpose of fixing the electrode. The active conductive material layer is connected to the external device through the electrode port to output the collected brain waves (bioelectric signals) to the external device.

[0043] Fixing the electrodes by magnetic attraction makes the collection of bioelectric signals stable and convenient. After fixing the second magnetic attraction component 14, the electrodes only need to be placed on the skin area of ​​interest to adsorb the electrodes on the skin epidermis to achieve electrode fixation. During the collection of bioelectric signals, the position of the electrodes can be changed at any time according to actual needs, which is convenient to operate.

[0044] The electrode uses a flexible conductive layer containing polydimethylsiloxane, which makes the electrode have good biocompatibility and stretchability, and can achieve a close connection with the epidermis of the affected area, ensuring fit and comfort. At the same time, graphene is mixed with silver nanowires to form a composite conductive material, which is deposited on the flexible conductive layer to form an active conductive material layer. Bioelectric signals are collected to reduce the interference caused by the user's limb movement or muscle tremors, making the collected bioelectric signals relatively stable and immune to motion artifacts. And because the electrode is in direct contact with the epidermis, a low electrode-skin interface impedance is generated, so the signal-to-noise ratio of the recorded bioelectric signal is relatively high, and EEG signals can be collected for a long time with a high signal-to-noise ratio.

[0045] Figure 1b This is a schematic diagram of the structure of another electrode provided by an exemplary embodiment of the present invention. The electrode of this embodiment has Figure 1a The active conductive material layer 11 , the flexible conductive layer 12 , the first magnetic attraction component 13 , and the second magnetic attraction component 14 shown also include a plurality of probes 15 .

[0046] A plurality of probes 15 are disposed on the flexible conductive layer 12 and are located on a surface away from the active conductive material layer 11. The plurality of probes 15 are dispersedly disposed on the flexible conductive layer 12. The plurality of probes 15 can be dispersedly disposed on the flexible conductive layer 12 in an array. The number and size of the probes 15 can be set according to actual needs, and the embodiment of the present invention does not specifically limit this. The shape of the probe 15 can be, for example, a cube shape.

[0047] A probe array formed of silver / silver chloride is fixed on one surface of the flexible conductive layer 12, which is used to contact the skin epidermis to obtain bioelectric signals; an active conductive material layer 11 containing graphene and silver nanowires is attached to the other surface of the flexible conductive layer, which is used to connect to the electrode connector to transmit the above-measured bioelectric signals to external devices. The probes on the flexible conductive layer 12 are in direct contact with the epidermis, which can reduce the interference caused by the user's limb movement or muscle tremor, making the collected EEG signals relatively stable, that is, the skin electrode is immune to motion artifacts and produces low electrode-skin interface impedance, so the recorded EEG has a high noise-to-electricity ratio.

[0048] The probe is made of high-purity silver and silver chloride mixed in a certain ratio, which can accurately measure weak bioelectric signals, such as weak brain electrical signals. The mass ratio of silver to silver chloride is between 1:0.05-1:3.5. Within this range, the electrode potential of the electrode probe is stable and the impedance is low.

[0049] Figure 2 A flowchart of a method for manufacturing an electrode provided by an exemplary embodiment of the present invention is shown in FIG. Figure 2 , the preparation method comprises the following steps:

[0050] Step 201: Disperse a polydimethylsiloxane solution on a first film, add carbon black particles to form a flexible conductive layer, and implant a first magnetic attraction component in the flexible conductive layer.

[0051] In another embodiment, other conductive materials may be added to the polydimethylsiloxane solution, and are not limited to particle-shaped carbon black.

[0052] In the production of the flexible conductive layer, the main agent of polydimethylsiloxane and the curing agent are mixed and stirred at a mass ratio of 10:1, and an appropriate amount of granular carbon black is added. The obtained mixture is evenly dispersed on the first film. The first film can be, but is not limited to, polyethylene terephthalate (PET). After curing, a polydimethylsiloxane film is obtained. The polydimethylsiloxane film is photoetched by laser to obtain a flexible conductive layer that matches the shape of the diseased part, for example, the shape of the flexible conductive layer is a rectangle of 50mm×75mm. A first magnetic attraction component is implanted in the flexible conductive layer so as to be connected to a second magnetic attraction component (for example, a fixing needle with magnetic attraction properties).

[0053] In one embodiment, the content of carbon black is about 20% to increase the conductivity of the flexible conductive layer.

[0054] Step 202: drop-coat a graphene solution on the surface of a solid substrate to obtain a graphene layer.

[0055] In the process of making the active conductive material layer, graphene is prepared by reducing graphene oxide, which is conducive to the transfer of graphene to the flexible conductive layer. Specifically, a graphene oxide solution is drop-coated on the surface of a plasma-treated solid substrate (flexible substrate) by a drop coating method, and a graphene oxide film is formed on the solid substrate after drying to obtain a graphene layer.

[0056] Step 203: spray silver nanowires on the surface of the graphene layer to obtain an active conductive material layer.

[0057] A full solution method is used, that is, silver nanowires synthesized by methods such as polyols are uniformly dispersed in water, ethanol or isopropanol solution, and then the obtained silver nanowire alcohol solution is immersed, dripped or sprayed on the surface of the graphene layer, so that the silver nanowires are adsorbed on the surface of the graphene layer to form a conductive network, and finally the graphene layer adsorbed with silver nanowires is oxidized and reduced to obtain an active conductive material layer.

[0058] The active conductive material layer is insensitive to stretching, which is conducive to the stable collection of bioelectric signals. Compared with a single material, reduced graphene oxide or silver nanowires, the conductivity is further enhanced. Due to the characteristics of silver, the active conductive material layer also has certain antibacterial and anti-ultraviolet properties.

[0059] Step 204 : depositing a flexible conductive layer implanted with the first magnetic attraction component on the first surface of the active conductive material layer.

[0060] Using a simple solution deposition method, such as screen printing or inkjet printing, the first surface of the active conductive material layer is deposited on the flexible conductive layer implanted into the first magnetic attraction component to obtain Figure 1a The electrodes are shown.

[0061] In one embodiment, an electrode port is led out from the surface of the active conductive material layer, and the electrode port is used to connect to an external device and output the bioelectric signal collected by the active conductive material layer to the external device.

[0062] Figure 3 A flowchart of another method for manufacturing an electrode provided by an exemplary embodiment of the present invention, the manufacturing method comprises the following steps:

[0063] Step 301: Disperse a polydimethylsiloxane solution on a first film, add carbon black particles to form a flexible conductive layer, and implant a first magnetic attraction component in the flexible conductive layer.

[0064] In the production of the flexible conductive layer, the main agent of polydimethylsiloxane and the curing agent are mixed at a mass ratio of 10:1 and stirred evenly, and the obtained mixture is evenly dispersed on the first film. The first film can be but not limited to polyethylene terephthalate (PET), and after curing, a polydimethylsiloxane film is obtained. The above polydimethylsiloxane film is photoetched by laser to obtain a flexible conductive layer matching the shape of the diseased part, for example, the shape of the flexible conductive layer is a rectangle of 50mm×75mm. A first magnetic attraction component is implanted in the flexible conductive layer so as to be connected to a second magnetic attraction component (for example, an electrode connector with magnetic attraction properties).

[0065] Step 302: drop-coat a graphene solution on the surface of a solid substrate to obtain a graphene layer.

[0066] Using a drop coating method, a graphene oxide solution is drop coated on the surface of a plasma treated solid substrate, and after drying, a graphene oxide film is formed on the solid substrate to obtain a graphene layer.

[0067] Step 303: spray silver nanowires on the surface of the graphene layer to obtain an active conductive material layer.

[0068] A full solution method is used, that is, silver nanowires synthesized by methods such as polyols are uniformly dispersed in water, ethanol or isopropanol solution, and then the obtained silver nanowire alcohol solution is immersed, dripped or sprayed on the surface of the graphene layer, so that the silver nanowires are adsorbed on the surface of the graphene layer to form a conductive network, and finally the graphene layer adsorbed with silver nanowires is oxidized and reduced to obtain an active conductive material layer.

[0069] The active conductive material layer is insensitive to stretching, which is conducive to the stable collection of bioelectric signals. Compared with a single material, reduced graphene oxide or silver nanowires, the conductivity is further enhanced. Due to the characteristics of silver, the active conductive material layer also has certain antibacterial and anti-ultraviolet properties.

[0070] Step 304 : depositing a flexible conductive layer implanted with the first magnetic attraction component on the first surface of the active conductive material layer.

[0071] Using a simple solution deposition method, such as screen printing or inkjet printing, the first surface of the active conductive material layer is deposited on the flexible conductive layer implanted into the first magnetic attraction component to obtain Figure 1a The electrode shown in the figure is drawn out from the surface of the active conductive material layer to obtain a skin electrode.

[0072] In one embodiment, an electrode port is led out from the surface of the active conductive material layer, and the electrode port is used to connect to an external device and output the bioelectric signal collected by the active conductive material layer to the external device.

[0073] Step 305: Make a probe by mixing silver and silver chloride in a preset ratio, and fix it on a surface of the flexible conductive layer.

[0074] In the process of making the silver / silver chloride probe, high-purity silver and silver chloride are mixed in a certain proportion, pressed into a cube shape under strong pressure, and fixed on one surface of the flexible conductive layer.

[0075] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. An electrode, characterized in that: include: The active conductive material layer is used to transmit the bioelectrical signals collected by the flexible conductive layer at the diseased part; The flexible conductive layer is disposed on the first surface of the active conductive material layer; A first magnetic attraction component is disposed in the flexible conductive layer, and the first magnetic attraction component is used to be mutually attracted with a second magnetic attraction component fixed inside the diseased part to fix the electrode; A plurality of probes, wherein the plurality of probes are disposed on the flexible conductive layer and are located on a surface away from the active conductive material layer; Wherein, the method for manufacturing the electrode comprises: Dispersing a polydimethylsiloxane solution on the first film and adding carbon black in particle form to form a flexible conductive layer; Implanting a first magnetic attraction component in the flexible conductive layer; Drop coating a graphene solution on the surface of a solid substrate to obtain a graphene layer; spraying silver nanowires on the surface of the graphene layer to obtain an active conductive material layer; A flexible conductive layer implanted with the first magnetic attraction component is deposited on the first surface of the active conductive material layer.

2. The electrode according to claim 1, characterized in that The active conductive material layer is provided with an electrode port, and the electrode port is used to connect to an external device and output the bioelectric signal to the external device.

3. The electrode according to claim 1, characterized in that The material of the flexible conductive layer includes polydimethylsiloxane and particle-shaped carbon black.

4. The electrode according to any one of claims 1 to 3, characterized in that The active conductive material layer includes graphene and silver nanowires.

5. The electrode according to claim 1, characterized in that The method for making the electrode further comprises: Silver and silver chloride mixed in a preset ratio are made into a probe, and the probe is fixed on a surface of the flexible conductive layer.

6. The electrode according to claim 1, characterized in that The polydimethylsiloxane solution includes a polydimethylsiloxane main agent and a curing agent, and the mass ratio of the polydimethylsiloxane main agent to the curing agent is 10:

1.

7. The electrode according to claim 1, characterized in that Silver nanowires are sprayed on the surface of the graphene layer to obtain the active conductive material layer. The method for making the electrode includes: Spraying silver nanowires on the surface of the graphene layer so that the silver nanowires are adsorbed on the surface of the graphene layer to form a conductive network; The active conductive material layer is obtained by oxidizing and reducing the graphene layer adsorbed with the silver nanowires.

8. The electrode according to claim 1, characterized in that The method for making the electrode further comprises: An electrode port is drawn out from the surface of the active conductive material layer.

Images