Fabric electromyography bracelet structure and process thereof

Abstract

The application relates to a fabric electromyography bracelet structure and a process thereof, which comprises, from inside to outside, a fabric shell, a flexible circuit board and an elastic fabric skin layer; the flexible circuit board is installed on the fabric shell, and the flexible circuit board is provided with electrodes arranged in an array; the elastic fabric skin layer comprises a fabric layer and an elastomer; the fabric layer is integrated with the fabric shell; the elastomer is fixedly connected with the fabric layer; and the elastomer encapsulates each electrode, so that each electrode can pass through the elastomer to contact human skin to collect electromyography signals. The application has the advantages of good electrical connection performance, softness, air permeability, good stretchability and comfortable wearing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wearable devices, in particular to a fabric electromyography bracelet structure and a process thereof. BACKGROUND

[0002] The existing flexible electromyography bracelet is usually composed of electrodes and a flexible substrate. The electrode material is mainly metal or conductive polymer material, and the flexible substrate is mainly rubber or elastic polymer. As the second skin of the human body, fabric has a good application prospect in the field of wearable electronics due to its superior mechanical properties, flexibility, moisture absorption and air permeability.

[0003] However, the connection between the fabric substrate and the hard circuit board is unstable, resulting in poor electrical connection. For example, the electromyography wristband based on elastic nylon cloth disclosed in Chinese patent CN 109998542 A connects the electrodes and the circuit by conductive glue, but the conductivity and stability of the conductive glue on the market are not satisfactory. Secondly, the wristband in the article has a large area and a complex structure, and can accommodate a small number of electrodes, which greatly limits the possibility of application. At the same time, the copper electrode and the circuit board are bound by the pores of the fabric, which causes wear and tear after long-term use, resulting in loosening of the circuit board-fabric and displacement of the electrodes during monitoring, making it difficult to monitor effective electrical signals.

[0004] Therefore, there is an urgent need for a fabric electromyography bracelet structure and a process thereof that can solve the above problems. SUMMARY

[0005] The present application aims to solve the above problems in the prior art and provides a fabric electromyography bracelet structure and a process thereof.

[0006] In order to achieve the above-mentioned application purposes, the present application adopts the following technical solutions: a fabric electromyography bracelet structure includes a fabric shell, a flexible circuit board and an elastic fabric skin layer arranged in order from inside to outside;

[0007] The flexible circuit board is installed on the fabric shell, and the flexible circuit board is provided with electrodes arranged in an array;

[0008] The elastic fabric skin layer includes a fabric layer and an elastomer, the fabric layer is integrated with the fabric shell, the elastomer is fixedly connected with the fabric layer, and the elastomer encapsulates each electrode, so that each electrode can contact the human skin through the elastomer to collect electromyography signals.

[0009] Working principle and beneficial effects: 1. Compared with the prior art, the present application has an elastic fabric skin layer, a flexible circuit board and a fabric shell from inside to outside. The elastic fabric skin layer can be arranged alternately by a high molecular elastomer and a nylon cloth. The elastomer is used to encapsulate the electrodes and the circuit, and the nylon cloth provides softness and air permeability, thereby optimizing the wearing experience and solving the problem of the connection between the fabric substrate and the hard circuit board.

[0010] 2、Compared with the prior art, the fabric layer is integrated with the fabric shell, so that the flexible circuit board can be well fixed, and the electrode can be welded on the flexible circuit board, thereby ensuring that the electrode cannot be easily loosened, circuit board-fabric loosening and electrode displacement during monitoring are avoided, and effective electrical signals are difficult to monitor.

[0011] Further, the fabric shell is provided with a magic tape or a buckle or a magnetic attraction structure for wearing. This arrangement can conveniently wear the bracelet.

[0012] Further, the fabric shell is made of elastic nylon fabric. This arrangement utilizes the good elasticity and air permeability of the elastic nylon fabric to make the bracelet more comfortable and light.

[0013] Further, the fabric layer is made of elastic nylon fabric or polyester fabric or polyester / cotton / nylon blended fabric. This arrangement can provide comfortable, light and skin-friendly effects.

[0014] Further, the elastomer is one of single-component or multi-component silicone glue, epoxy resin glue, polyurethane encapsulation glue and light-cured encapsulation glue. This arrangement can provide good electrical insulation, high temperature resistance and strength, and play a role in protecting electrical components.

[0015] The fabric electromyography bracelet manufacturing process is used to manufacture the fabric electromyography bracelet structure described above, and includes the following steps:

[0016] The raw rubber, vulcanizing agent, reinforcing agent and additives are mixed in proportion, then vacuum degassed and mixed to form a glue slurry, which is stored for use;

[0017] The glue slurry formula is: 95-100 parts of silicone rubber, 0.5-1 parts of vulcanizing agent, 30-55 parts of reinforcing filler, and 2-5 parts of additives;

[0018] Polyester or polyimide is used as a base material, and a metal circuit is printed or chemically etched or laser engraved, and a metal electrode is welded on the electrode disc of the base material to form a flexible circuit board;

[0019] The fabric is heat set before gluing, the fabric surface is coated with an adhesive to form a double-layer fabric shell, and a strip-shaped opening is cut in the inner layer of the double-layer fabric according to the position of the metal electrode to form the fabric shell;

[0020] The flexible circuit board is wrapped in the fabric shell, and the spare glue slurry is evenly coated on the designed position of the fabric shell to expose the metal electrode;

[0021] After drying and vulcanization / ultraviolet curing, the glue slurry solidifies to form a silicone glue connecting the flexible circuit board and the fabric as a whole.

[0022] Further, the reinforcing agent is one or more of fumed white carbon black and precipitated white carbon black. Fumed white carbon black is one of the most important nanometer inorganic raw materials. Because of its small particle size, it has a large specific surface area, strong surface adsorption, large surface energy, high chemical purity, good dispersion performance, and special properties in thermal resistance, electrical resistance, etc. It has unique properties and irreplaceable role in many disciplines and fields due to its superior stability, reinforcement, thickening, and thixotropy. Precipitated white carbon black, also known as hydrated silicon dioxide, active silicon dioxide, precipitated silicon dioxide, and precipitated hydrated silicon dioxide, has high temperature resistance, non-combustibility, no odor, no smell, and good electrical insulation. Therefore, it is very suitable for use in flexible circuit board packaging.

[0023] Further, the adhesive is a solution composed of ethyl acetate / ethanol, alkoxysilane, borate ester, and vulcanizing agent. After treatment with the adhesive, the combination of the silicone elastomer and the fabric can be promoted.

[0024] Further, the additive is a heat aging stabilizer.

[0025] Further, the drying time at room temperature is 30-60 minutes. Drying at a temperature of 65°C (150°F) in an oven for 10 to 15 minutes can shorten the drying time.

[0026] Further, the vulcanizing agent is one or more of benzoyl peroxide, 2-4-dichloro benzoyl peroxide, t-butyl peroxybenzoate, di-t-butyl peroxide, and dicumyl peroxide.

[0027] Further, the vulcanization temperature is 120°C, and the time is 10-30 minutes. With this setting, vulcanization, also known as cross-linking and curing, is the process of converting linear macromolecules into a three-dimensional network structure in rubber by adding vulcanizing agents and accelerators, etc. cross-linking aids, under certain temperature and pressure conditions. After vulcanization, the rubber / silicone rubber changes its inherent low strength, small elasticity, cold hardening, hot sticking, and easy aging defects, and significantly improves the wear resistance, swelling resistance, heat resistance, and other aspects, expanding the application range. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a schematic diagram of the bracelet structure of the present application;

[0029] Figure 2 is a process flow diagram of the present application;

[0030] Figure 3 is an EMG signal diagram of the full silicone rubber No. 1 bracelet in Example 3;

[0031] Figure 4 is an EMG signal diagram of the full fabric bracelet No. 2 in Example 3;

[0032] Figure 5This is the EMG signal diagram of the elastomer-fabric wristband No. 3 in Example 3.

[0033] In the diagram, 1 is the fabric outer shell; 2 is the flexible circuit board; 3 is the elastic fabric skin-friendly layer; and 4 is the metal electrode. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0035] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0036] Example 1

[0037] like Figure 1 As shown, the structure of this fabric electromyography bracelet includes a fabric outer shell 1, a flexible circuit board 2, and an elastic fabric skin-friendly layer 3 arranged sequentially from the inside to the outside.

[0038] The fabric outer shell 1 is equipped with Velcro, snaps, or magnetic closures, allowing for adjustable size for wearing. In this embodiment, the fabric outer shell 1 is made of elastic nylon or a similar or better material.

[0039] The flexible circuit board 2 is mounted on the fabric housing 1, and the flexible circuit board 2 has an array of electrodes. In this embodiment, the flexible circuit board 2 is a printed circuit board with a polyester or polyimide substrate, and the flexible circuit board 2 (FPC) can be installed inside the fabric housing 1. Metal electrodes 4 are soldered onto the flexible circuit board 2, and the electrodes are arranged as n pairs of differential electrodes and n reference electrodes, where n is 8-16.

[0040] Preferably, the metal electrode 4 is made of a 1mm high copper column.

[0041] The elastic fabric skin-friendly layer 3 includes a fabric layer and an elastomer. The fabric layer is integral with the fabric shell 1, and the elastomer is fixed to the fabric layer. The elastomer encapsulates each electrode so that each electrode can pass through the elastomer to contact human skin and collect electromyographic signals.

[0042] In the present embodiment, the fabric layer portion is the same nylon fabric as the fabric shell 1, can be formed integrally with the fabric shell 1, or sewn together. Of course, it can also be replaced by a cheaper polyester fabric, or a more comfortable and better feeling polyester / cotton blended fabric.

[0043] Preferably, the elastomer is selected as a liquid silicone, and the silicone is integrated on the fabric through a hot pressing process; at the same time, the silicone encapsulates the metal electrode 4, but does not exceed the height of the electrode. In the present embodiment, the elastomer can be selected from single-component or multi-component silicone, epoxy resin, polyurethane encapsulation glue, or light-cured encapsulation glue. The above-mentioned materials have good electrical insulation, high temperature resistance, and strength, and can protect the electrical components. At the same time, the elastomer can penetrate into the fabric, and after warming or ultraviolet light curing, an integrated encapsulation structure can be formed.

[0044] Embodiment 2

[0045] The present embodiment is used to manufacture the fabric electromyography bracelet structure of embodiment 1, as shown in Figure 2 , including the following steps:

[0046] Step 1, after mixing the raw rubber, vulcanizing agent, reinforcing agent and additives in proportion, vacuum degassing and mixing to form a rubber slurry, store for use, the storage temperature is not more than 25°C;

[0047] Among them, the rubber slurry formula is: silicone rubber 95-100 parts, vulcanizing agent 0.5-1 part, reinforcing filler 30-55 parts, additives 2-5 parts;

[0048] The preferred ratio 1 is: silicone rubber 97 parts, vulcanizing agent 0.5 parts, reinforcing agent 40 parts, and additives 2 parts.

[0049] Control 2: silicone rubber 95 parts, vulcanizing agent 0.5 parts, reinforcing agent 30 parts, and additives 2 parts.

[0050] Control 3: silicone rubber 99 parts, vulcanizing agent 0.75 parts, reinforcing agent 50 parts, and additives 2 parts.

[0051] The physical performance indicators of the three silicone samples are shown in Table 1:

[0052]

[0053] Table 1

[0054] Therefore, based on Table 1 above, it can be seen that the silicone elastomer and hardness under the present formula ratio are moderate, and the strength is high, which can protect the circuit, and also meet the comfort of wearing.

[0055] In the present embodiment, the vulcanizing agent is one or more of benzoyl peroxide, 2-4-dichlorobenzoyl peroxide, t-butyl peroxybenzoate, di-t-butyl peroxide and dicumyl peroxide; and the additive is a heat aging stabilizer.

[0056] In the present embodiment, the reinforcing agent is fumed silica, and can also be precipitated silica; and the raw rubber is, for example, a single-component liquid silicone rubber of type 110 or type 112 methyl vinyl silicone rubber.

[0057] Step 2, printing or etching or laser engraving a metal circuit on a polyester or polyimide substrate, and welding a metal electrode 4 on the electrode disc of the substrate to form a flexible circuit board 2.

[0058] In the present embodiment, the flexible circuit board 2 is provided with electrode discs, and a metal copper column is welded on the disc for sensing.

[0059] Step 3, after heat setting of the fabric before gluing, the fabric surface is coated with an adhesive to form a double-layer fabric shell 1, and a strip-shaped opening is cut in the inner layer of the double-layer fabric according to the position of the metal electrode 4 to form the fabric shell 1.

[0060] In the present embodiment, the heat setting of the fabric before gluing is a short-time heat treatment of the fabric at a certain draft, and the treatment temperature is 170-175°C.

[0061] In the present embodiment, the size of the fabric shell 1 is slightly larger than the size of the flexible circuit board 2, so that the flexible circuit board 2 can be fitted into the fabric shell 1.

[0062] In the present embodiment, the adhesive is a solution of alkoxysilane, borate ester, vulcanizing agent and solvent (ethyl acetate or ethanol).

[0063] Step 4, the flexible circuit board 2 is wrapped in the fabric shell 1, and the spare adhesive paste is uniformly coated on the designed position of the fabric shell 1, so that the metal electrode 4 is exposed.

[0064] In the present embodiment, the adhesive paste is uniformly coated on the reserved (designed) position of the fabric by using a glue coating machine.

[0065] Step 5, after drying and vulcanization / ultraviolet curing, the adhesive paste is cured to form a silicone rubber connecting the flexible circuit board 2 and the fabric into a whole, and the manufacturing of the bracelet structure is completed.

[0066] In the present embodiment, the drying time is 30 minutes, and the vulcanization temperature is 120°C, and the time is 10-30 minutes.

[0067] Thus, the subsequent circuit connection detection unit and data processing unit of the flexible circuit board 2 can be connected.

[0068] Example 3

[0069] This embodiment tests the capability of the fabric EMG bracelet structure of embodiment 1 or embodiment 2.

[0070] I. Physical performance test:

[0071] The use of fabric brings flexibility, elasticity, air and water permeability, and excellent conformability, not only improving comfort, but also good contact with the skin. The electrodes remain in place when performing various movements.

[0072] Table 2 below compares the stretchability of elastomer-fabric bracelet No. 3 with full silicone No. 1 and full fabric bracelet No. 2. Specifically, the bracelet is spread flat and manually stretched until the entire bracelet separates. Among them, full silicone No. 1 is very difficult to stretch, and the electrode is not separated from the silicone; the stretchability of the elastic nylon cloth is very high, but the electrode is separated from the elastic nylon cloth when the full fabric bracelet No. 2 is stretched to 120% of the original length; the elastomer-fabric bracelet No. 3 of the present application can be stretched by 150% without electrode displacement or separation, and can restore to the original state after the external force is removed.

[0073] Serial number Encapsulation material Stretchability Encapsulation effect 1 Silicone gel 105％ Not separated 2 Elastic nylon cloth 120％ Separated 3 Silicone gel-elastic nylon cloth 150％ Not separated

[0074] Table 2

[0075] In this way, the elastomer-fabric bracelet No. 3 of the present application has good physical properties compared to the prior art, and can effectively ensure that electrode displacement or separation does not occur under a large degree of stretching.

[0076] Among them, the stretchability in Table 1 refers to the maximum elongation rate when the silicone is stretched to break, while in Table 2, whether the bracelet structure will cause the FPC to separate after stretching is tested, and the bracelet cannot be broken, so a smaller constant force is required. Under the premise of the same force, the stretchability of each packaging material, so the stretch elongation rate in Table 1 will be significantly larger than the stretchability in Table 2.

[0077] II. EMG signal:

[0078] The 8-channel bracelet is worn on the wrist to collect electromyographic signals, with a frequency of 10 hz, and the EMG is shown in Figures 3-5, which can realize continuous dynamic acquisition of different gestures. Comparing the three different packaging materials of the bracelet (full silicone No. 1, full fabric bracelet No. 2, and elastomer-fabric bracelet No. 3), full fabric bracelet No. 2 and full silicone No. 1 have poor adhesion to the wrist and high noise level, and almost no effective signal can be collected during exercise. Only the elastomer-fabric bracelet No. 3 of the present application can accurately collect the signal changes during hand movement.

[0079] The part of the present application not described in detail is prior art, so the present application does not describe it in detail.

[0080] It is to be understood that the terms "one" and "a" should be construed to be "at least one" or "one or more" and that the terms "first," "second," and the like can not imply any actual physical or logical relationship between items described in the patent.

[0081] Although the terms fabric shell 1, flexible circuit board 2, elastic fabric skin layer 3, metal electrode 4, etc. are used more frequently in this document, the possibility of using other terms is not excluded. The use of these terms is only for the convenience of describing and explaining the essence of the present application; any interpretation of them as any kind of additional limitation is contrary to the spirit of the present application.

[0082] The present application is not limited to the above-mentioned best mode, and anyone can derive other various forms of products under the inspiration of the present application, but regardless of any change in shape or structure, any technical solution with the same or similar to the present application falls within the scope of the present application.

Claims

1. A fabric electromyography (EMG) bracelet structure, characterized in that, It includes a fabric outer shell, a flexible circuit board, and an elastic, skin-friendly fabric layer arranged sequentially from the inside out; The flexible circuit board is mounted on the fabric shell, and the flexible circuit board is provided with an array of electrodes; The elastic fabric skin-friendly layer includes a fabric layer and an elastomer. The fabric layer is integrally formed with the fabric shell, and the elastomer is fixedly connected to the fabric layer. The elastomer encapsulates each electrode so that each electrode can pass through the elastomer to contact human skin and collect electromyographic signals. The elastomer penetrates into the fabric layer and is cured to form an integral structure.

2. The fabric electromyography bracelet structure according to claim 1, characterized in that, The fabric outer shell is equipped with Velcro, buckles, or magnetic structures for wearing.

3. The fabric electromyography bracelet structure according to claim 1, characterized in that, The fabric outer shell is made of elastic nylon fabric.

4. The fabric electromyography bracelet structure according to claim 1, characterized in that, The fabric layer is made of elastic nylon fabric, polyester fabric, or polyester / cotton / nylon blended fabric.

5. The fabric electromyography bracelet structure according to claim 1, characterized in that, The elastomer is one of a single-component or multi-component silicone, epoxy resin, polyurethane encapsulant, or photocurable encapsulant.

6. A manufacturing process for a fabric myoelectric bracelet, characterized in that, The method for manufacturing a fabric electromyography bracelet structure according to any one of claims 1-5 includes the following steps: Raw rubber, vulcanizing agent, reinforcing agent and additives are mixed in proportion, and then vacuum degassed and mixed to form a rubber paste, which is then stored for later use. The adhesive formulation is as follows: 95-100 parts silicone rubber, 0.5-1 part vulcanizing agent, 30-55 parts reinforcing filler, and 2-5 parts additives; A flexible circuit board is formed by printing, chemically etching, or laser engraving metal lines on polyester or polyimide as the substrate, and welding metal electrodes on the electrode disk of the substrate. After the fabric is heat-set before the adhesive is applied, an adhesive is applied to the surface of the fabric to form a double-layer fabric shell. At the same time, strip-shaped openings are cut into the inner layer of the double-layer fabric according to the position of the metal electrode to form the fabric shell. The flexible circuit board is wrapped inside a fabric shell, and the prepared adhesive is evenly applied to the designed position on the fabric shell so that the metal electrodes are exposed. After drying and vulcanization / UV curing, the cured adhesive forms a silicone bond that integrates the flexible circuit board and fabric into a single unit.

7. The manufacturing process of the fabric myoelectric bracelet according to claim 6, characterized in that, The reinforcing agent is one or more of fumed silica and precipitated silica.

8. The manufacturing process of the fabric myoelectric bracelet according to claim 6, characterized in that, The adhesive is a solution composed of ethyl acetate / ethanol, alkoxysilane, borate ester and vulcanizing agent.

9. The manufacturing process of the fabric myoelectric bracelet according to claim 6, characterized in that, The additive is a heat aging stabilizer.

10. The manufacturing process of the fabric myoelectric bracelet according to claim 6, characterized in that, The vulcanizing agent is one or more of benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butyl peroxide, di-tert-butyl peroxide, and dicumyl peroxide.

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