A system and method for preparing electrostatic flocking bioelectrical signal monitoring sensor fabric

Abstract

The present invention relates to a preparation system and method of an electrostatic flocking bioelectric signal monitoring and sensing fabric, comprising a base layer made of a conductive material, the top surface of the base layer being arranged as a curved surface structure that fits a part of the human body, a stepped mold layer extending on the curved surface structure, the stepped mold layer being composed of a plurality of accommodating cavities with openings facing upward, the accommodating cavities being sequentially filled with and accommodating a conductive adhesive along the surface of the curved surface structure; a nozzle is arranged above the curved surface structure, the nozzle sprays a fiber body downward toward the accommodating cavity, the fiber body being a conductor; the system also comprises a horizontal electrode plate group arranged in parallel and spaced intervals above and below the base layer, and a vertical electrode plate group arranged in parallel and spaced intervals on both sides of the base layer, the horizontal electrode plate group and the vertical electrode plate group being energized to form a composite electric field; a flocking fabric perpendicular to the curved surface is obtained by vertically arranging the fiber body on the curved surface of the base layer, effectively ensuring the contact area with the skin, the concept is novel, and greatly helps to improve and ensure the quality of bioelectric signal monitoring.

Description

Technical Field

[0001] The present invention relates to the technical field of textile materials, and in particular to a system and method for preparing electrostatic flocking bioelectric signal monitoring sensor fabric. Background Art

[0002] With the development of science and technology, more and more wearable bioelectrical signal monitoring systems are being used to monitor vital signs and achieve health management in daily life. For example, various wearable sensors have been reported for measuring pulse, peripheral blood oxygen saturation, body temperature, blood flow, and electrocardiogram (ECG). In particular, there is a high demand for wearable measurement sensors that measure bioelectrical signals such as electrocardiogram (ECG), electroencephalogram (EEG), or electromyogram (EMG), as bioelectrical signals are important physiological indicators related to human health.

[0003] Take the electrocardiogram (ECG) signal, for example. As a bioelectrical signal, it is commonly used to diagnose various heart diseases and plays a crucial role in preventing death from heart diseases. Electrode sensors that measure ECG signals convert the potential and current of biological ions into electronic signals and are typically placed on the skin of the chest and limbs. In recent years, research on wearable electronic clothing for monitoring human physiological electrical signals has increased. Fabric-based electrical signal monitoring sensors for electronic clothing, manufactured using textile processes using fibers, yarns, and fabrics, are also becoming increasingly important.

[0004] Ordinary fabric-based electrical signal detection sensors have a small contact area with the skin, resulting in high skin contact impedance. This often causes noise when measuring bioelectrical signals, leading to inaccurate bioelectrical signal detection. To address this problem, velvet fabrics are covered with a large amount of velvet on their surface. This feature can increase the contact area between the electrical signal detection fabric sensor and the skin, thereby reducing the contact impedance between the sensor and the skin and improving the quality of bioelectrical signal monitoring. Summary of the Invention

[0005] In response to the shortcomings of the above-mentioned existing production technology, the applicant provides a rationally structured electrostatic flocking bioelectric signal monitoring sensor fabric preparation system and method, which can reliably prepare fluff-type sensor fabrics to effectively increase the contact area between the sensor fabric and the human body, solve the problem of large contact impedance caused by small contact area, and help stabilize the transmission of bioelectric signals.

[0006] The technical solutions adopted in the present invention are as follows:

[0007] A preparation system for an electrostatic flocking bioelectric signal monitoring and sensing fabric comprises a base layer made of a conductive material, the top surface of the base layer being configured as a curved structure that fits a part of the human body, a stepped mold layer extending from the curved structure of the base layer, the stepped mold layer being composed of a plurality of accommodating cavities with openings facing upwards, the accommodating cavities being sequentially distributed along the surface of the curved structure, the accommodating cavities containing a conductive adhesive; a nozzle is provided above the curved structure, the nozzle spraying a fiber body downwardly toward the accommodating cavity, the fiber body being a conductor; the system also comprises a horizontal electrode plate group arranged in parallel and spaced apart above and below the base layer, and a vertical electrode plate group arranged in parallel and spaced apart on both sides of the base layer, the horizontal electrode plate group and the vertical electrode plate group being energized to form a composite electric field.

[0008] As a further improvement of the above technical solution:

[0009] The vertical electrode plate group and the horizontal electrode plate group are electrically connected to the steering power supply, and the steering power supply changes the voltage value and / or polarity of the vertical electrode plate group and / or the horizontal electrode plate group, thereby changing the electric field direction of the composite electric field, and adjusting the posture of the conductive fiber body by the change of the electric field force exerted on the conductive fiber body in the composite electric field; the nozzle and the base layer are electrically connected to the conductive power supply.

[0010] The nozzle is a porous nozzle that sprays both the fiber body and ultraviolet rays. The ultraviolet rays are irradiated toward the accommodating cavity, and the ultraviolet rays cause the adhesive with the fiber body in the accommodating cavity to solidify to form an adhesive layer.

[0011] The structure of the nozzle is as follows: it includes a nozzle body, an ultraviolet light outlet is opened in the middle of the bottom surface of the nozzle body, an ultraviolet light inlet is set on the side of the nozzle body, an external ultraviolet light source is incident into the nozzle body through the ultraviolet light inlet, and is deflected by a reflector to be emitted downward from the downward-facing ultraviolet light outlet; a plurality of fiber outlets are also set on the bottom surface of the nozzle body located outside the circumference of the ultraviolet light outlet, and a single fiber outlet is connected to the fiber inlet opened on the top surface of the nozzle body via a fiber channel; the fiber inlet is connected to an external fiber pumping device.

[0012] It also includes a power mechanism for driving the nozzle to move, and the power mechanism drives the nozzle to move along the moving track in the horizontal plane, so that the nozzle is located directly above the corresponding accommodating cavity.

[0013] A method for preparing an electrostatic flocking bioelectric signal monitoring sensor fabric based on the preparation system includes the following steps:

[0014] Prepare a base layer that fits the curved surface of a specific part of the human body, and 3D print a stepped mold layer on the curved structure of the base layer;

[0015] pouring the adhesive into the corresponding receiving cavities of the stepped mold layers;

[0016] The horizontal electrode plate group and the vertical electrode plate group are electrically connected to form a composite electric field, and the electric field direction of the composite electric field is adjusted to a preset direction; the fiber body is sprayed into the corresponding receiving cavity by the nozzle to perform flocking;

[0017] The fiber body adjusts its posture under the action of the composite electric field and is inserted into the adhesive in the normal direction of the curved surface structure at the corresponding accommodation cavity, and forms an adhesive layer as the adhesive solidifies;

[0018] Adjust the voltage of the horizontal electrode plate group and the vertical electrode plate group, and adjust the electric field direction of the composite electric field so that the fibers ejected successively through the nozzle are inserted into the adhesive of the corresponding position accommodating cavity in a direction consistent with the normal direction of the curved surface structure under the action of the composite electric field;

[0019] After flocking is completed in all the accommodating cavities on the base layer and solidified, the base layer is immersed in liquid to remove the graded mold layer, thereby obtaining a flocked bioelectric signal monitoring sensor fabric; and the flocked sensor fabric is dried.

[0020] As a further improvement of the above technical solution:

[0021] The adhesive layer is made of photosensitive resin material, and glass microspheres with silver-plated surfaces are added to the photosensitive resin material to provide conductive properties.

[0022] The stepped mold layer is a thin film layer made of a Pluronic material with a mass fraction of 30%-50%, and a plurality of accommodating cavities are formed by the thin film. After the flocking is cured, the stepped mold layer is immersed in clean water and removed. The stepped mold layer is formed by 3D printing.

[0023] The fiber body is a silver-plated polyester fiber with a length of 400-600 microns and a diameter of 15-25 microns.

[0024] The base layer includes a fabric layer woven from conductive yarns, the top surface of the fabric layer is provided with a curved surface structure, the surface of the curved surface structure is coated with a conductive adhesive to form an adhesive layer, and the adhesive layer is composed of epoxy resin added with conductive fillers.

[0025] The beneficial effects of the present invention are as follows:

[0026] The present invention has a compact and reasonable structure and is easy to operate. Based on the action of the composite electric field, it can vertically arrange the fiber body on the curved surface of the base layer, so as to reliably prepare the velvet sensing fabric, so as to effectively increase the contact area between the sensor prepared by the sensing fabric and the human body, and solve the problem of large contact impedance caused by the small contact area. The vertically arranged fiber body is also easier to insert into the human skin, reducing the relative slippage between the sensing fabric and the skin, and can better stabilize the bioelectric signal. The concept is novel and greatly helps to improve and ensure the quality of the bioelectric signal.

[0027] The present invention also includes the following advantages:

[0028] The base layer is equipped with a curved surface structure that fits the human body. The 3D printing technology is used to print a graded mold layer on the curved surface structure, effectively ensuring the contact area with the human skin, thereby reducing the contact impedance between the bioelectric signal monitoring sensor fabric and the skin. Of course, the reliable fit between the sensor fabric and the skin can also reduce the relative displacement between the human body and the sensor during exercise, making the contact impedance more stable.

[0029] The fiber body is made of silver-plated polyester fiber with large bending stiffness. During the electrostatic flocking process, the direction of the fiber body of each layer will be controlled by a real-time adjustable electric field to ensure that the fiber body inserted into the adhesive layer is as perpendicular as possible to the curved surface of the base layer of the bioelectric signal monitoring sensor fabric, so that more fiber bodies can be inserted vertically into the human skin to increase the contact area between the conductive fiber and the human skin, thereby reducing the contact impedance between the two; the length of the fiber body can be controlled within 400 to 600 microns, of which the proportion of the bottom end embedded in the adhesive is more than half, so that even if the fiber body is completely inserted into the skin, it will not exceed 300 microns. The fiber body of this length will not pass through the epidermis of the human skin and cause itching to the human body, thereby effectively ensuring wearing comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of the preparation system of the present invention.

[0031] Figure 2 Schematic diagram of the arrangement of the stepped mold layer on the base layer of the present invention.

[0032] Figure 3 It is a structural schematic diagram of the nozzle of the present invention.

[0033] Figure 4 It is a cross-sectional view of the nozzle of the present invention.

[0034] Figure 5 Schematic diagram of flocking on the base layer of the present invention.

[0035] Figure 6 for Figure 5 A partial enlarged view of point A in the middle.

[0036] Figure 7 Schematic diagram of the force on the fiber body of the present invention in a composite electric field.

[0037] Figure 8 This is a schematic structural diagram of the final flocking fabric of the present invention.

[0038] Among them: 1. Steering power supply; 2. Vertical electrode plate group; 3. Horizontal electrode plate group; 4. UV light source; 5. Stepped mold layer; 6. Moving track; 7. Nozzle; 8. Conductive power supply; 9. Fiber body; 10. Base layer; 11. Adhesive layer;

[0039] 51. Opposite wall; 52. Connecting wall;

[0040] 71. Nozzle body; 72. Fiber outlet; 73. UV light outlet; 74. Fiber channel; 75. Reflector; 76. Fiber inlet; 77. UV light inlet;

[0041] 101. Accommodation cavity. DETAILED DESCRIPTION

[0042] The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0043] like Figure 1 As shown, an electrostatic flocking bioelectric signal monitoring sensor fabric preparation system of this embodiment includes a base layer 10 made of a conductive material, the top surface of the base layer 10 is set as a curved structure that fits the human body part, and a stepped mold layer 5 is extended on the curved structure of the base layer 10, and the stepped mold layer 5 is composed of a plurality of accommodating cavities 101 with openings facing upward, and the accommodating cavities 101 are sequentially distributed along the surface of the curved structure, and the accommodating cavities 101 contain a conductive adhesive; a nozzle 7 is provided above the curved structure, and the nozzle 7 sprays a fiber body 9 downward toward the accommodating cavity 101, and the fiber body 9 is a conductor; it also includes a horizontal electrode plate group 3 arranged in parallel and spaced above and below the base layer 10, and a vertical electrode plate group 2 arranged in parallel and spaced on both sides of the base layer 10, and the horizontal electrode plate group 3 and the vertical electrode plate group 2 are energized to form a composite electric field.

[0044] Based on the effect of the composite electric field, the fiber body 9 can be arranged vertically on the curved surface of the base layer 10, so as to reliably prepare the fluff-type sensing fabric, thereby effectively increasing the contact area between the sensing fabric and the human body and solving the problem of large contact impedance caused by small contact area.

[0045] The fiber body 9 is subjected to the electric field force in the composite electric field and adjusts its posture. The fiber body 9 is inserted into the adhesive of the corresponding accommodation cavity 101, and the length direction of the fiber body 9 is consistent with the normal direction of the curved surface structure.

[0046] The vertical electrode plate group 2 and the horizontal electrode plate group 3 are electrically connected to the steering power supply 1, and the steering power supply 1 changes the voltage value and / or polarity of the vertical electrode plate group 2 and / or the horizontal electrode plate group 3, thereby changing the electric field direction of the composite electric field, and adjusting the posture of the conductive fiber body 9 by the change of the electric field force exerted on the conductive fiber body 9 in the composite electric field; the nozzle 7 and the base layer 10 are electrically connected to the conductive power supply 8.

[0047] By changing the voltage value of one or two of the vertical electrode plate group 2 and the horizontal electrode plate group 3, the electric field direction of the composite electric field is adjusted, and then the force direction of the fiber body 9 in the composite electric field is adjusted; by adjusting the polarity of the vertical electrode plate group 2 and the horizontal electrode plate group 3, the direction of the force direction of the fiber body 9 can be adjusted.

[0048] like Figure 2 As shown, a single accommodating cavity 101 in the stepped mold layer 5 can be composed of opposite walls 51 on both sides, a connecting wall 52 connected to the ends of the opposite walls 51 , and a curved surface structure below.

[0049] The nozzle 7 is a porous nozzle that can spray both the fiber body 9 and ultraviolet rays. The ultraviolet rays are irradiated toward the accommodating cavity 101. The ultraviolet rays cause the adhesive with the fiber body 9 in the accommodating cavity 101 to solidify, forming an adhesive layer 11. Therefore, after the fiber body 9 is sprayed out, the ultraviolet rays can be irradiated immediately to make the adhesive with the fiber body 9 solidify in time, thereby effectively saving the running track of the nozzle 7 or simplifying the device, and having good practicality.

[0050] like Figure 3 and Figure 4 As shown, the structure of the nozzle 7 is as follows: it includes a nozzle body 71, a UV light outlet 73 is opened in the middle of the bottom surface of the nozzle body 71, and a UV light inlet 77 is provided on the side of the nozzle body 71. The external UV light source 4 is incident into the nozzle body 71 through the UV light inlet 77, and is deflected by the reflector 75 to be emitted downward from the downward-facing UV light outlet 73; a plurality of fiber outlets 72 are also provided on the bottom surface of the nozzle body 71 located outside the UV light outlet 73 in the circumferential direction, and a single fiber outlet 72 is connected to a fiber inlet 76 opened on the top surface of the nozzle body 71 through a fiber channel 74; the fiber inlet 76 is connected to an external fiber pumping device.

[0051] The ultraviolet light outlet 73 is formed of insulating materials such as plastic to prevent excessive charge from accumulating at the outlet end.

[0052] The inner wall of the fiber channel 74 is smooth to reduce the resistance encountered by the fiber body 9 during transportation; of course, the diameter of the fiber channel 74 can be set to be slightly larger than the fiber body 9, such as 25 microns, to prevent multiple fibers from running in parallel, thereby effectively ensuring the flocking effect.

[0053] It also includes a power mechanism for driving the nozzle 7 to move. The power mechanism drives the nozzle 7 to move along the moving track 6 in a horizontal plane, so that the nozzle 7 is located directly above the corresponding accommodating cavity 101.

[0054] In this embodiment, the stepped mold layer 5 is formed by 3D printing, and together with the base layer 10, they are all curved structures that fit the human body; the more mold steps in the stepped mold layer 5, the smoother the surface of the sensing fabric will be and the better the fit.

[0055] A curved surface structure that fits the human body parts is provided on the base layer 10. The stepped mold layer 5 is printed on the curved surface structure using 3D printing technology, which effectively ensures the fitting area with the human skin, thereby reducing the contact impedance between the bioelectric signal monitoring sensor fabric and the skin. Of course, the reliable fit between the sensor fabric and the skin can also reduce the relative displacement between the human body and the sensor during exercise, making the contact impedance more stable.

[0056] In this embodiment, the change in the electric field in the composite electric field is achieved by the vertical electrode plate group 2 and the horizontal electrode plate group 3. The upper and lower electrode plates can be respectively connected to a set positive voltage and a zero level, while the positive and negative voltages of the left and right electrode plates are not fixed (either a positive voltage can be connected to the left electrode plate and a zero level to the right electrode plate, or a positive voltage can be connected to the right electrode plate and a zero level to the left electrode plate, depending on the desired electric field direction). The distance between the upper and lower electrode plates and the left and right electrode plates can be set to 5 to 20 cm, depending on the size of the designed bioelectric signal monitoring sensor fabric.

[0057] For example, the distance between the upper and lower and left and right electrode plates is set to 10 cm, the potential difference between the upper and lower plates is 80 kV (U), and the potential difference between the left and right plates is the value to be set, which can be expressed as U'. α is the minimum angle between the composite electric field direction and the normal of the lower electrode plate, such as Figure 7 As shown;

[0058] It turns out that:

[0059] Therefore, if you want the angle α to be 10°, you can adjust the right electrode plate to 14.1kV and the left electrode plate to 0V; when α is increased by 1°, the voltage of the right electrode plate can be increased by 1.5kV, that is, set to 15.6kV, and the angle α can be increased to 11°.

[0060] To achieve perpendicularity between the silver-plated fibers and the curved surface of the substrate, the angle between the curved surface normal and the horizontal plane normal of each mold layer can be recorded during the initial design of the substrate. By adjusting the corresponding voltage, the direction of the electric field intensity can be aligned with the curved surface normal. In the actual preparation of bioelectric signal monitoring sensor fabrics, if the weight of certain staple fibers used in the preparation is not negligible compared to the electric field force, the voltage value can be adjusted to a certain extent. The gravity of most raw staple fibers is negligible compared to the magnitude of the electric field force.

[0061] To achieve automatic adjustment of the power supply size, a computer control program for the power supply can be written based on the above principle. The angle β between the normal line of the arc surface of each layer of the mold and the normal line of the horizontal surface, the movement rate of the nozzle, the duration of light curing, the injection rate of the silver-plated fiber, the size (length and width) of the bioelectric signal monitoring sensor fabric and other parameters are used as input values. Taking the movement path of the nozzle into comprehensive consideration, the output voltage value after calculation is substituted into the program to achieve automatic adjustment of the direction of the electrostatic flocking electric field.

[0062] The method for preparing the electrostatic flocking bioelectric signal monitoring sensor fabric based on the preparation system of this embodiment includes the following steps:

[0063] Step 1: Prepare a base layer 10 that fits the curved surface of a specific part of the human body, and form a stepped mold layer 5 on the curved surface structure of the base layer 10 by 3D printing;

[0064] Step 2: Pour the adhesive into the corresponding accommodating cavity 101 of the stepped mold layer 5;

[0065] Step 3: The horizontal electrode plate group 3 and the vertical electrode plate group 2 are electrically connected to form a composite electric field, and the electric field direction of the composite electric field is adjusted to a preset direction; the fiber body 9 is sprayed into the corresponding receiving cavity 101 by the nozzle 7 to perform flocking;

[0066] Step 4: The fiber body 9 adjusts its posture under the action of the composite electric field and is inserted into the adhesive in the normal direction of the curved surface structure at the corresponding accommodation cavity 101, and forms an adhesive layer 11 as the adhesive solidifies;

[0067] Step 5: Adjust the voltage of the horizontal electrode plate group 3 and the vertical electrode plate group 2, and adjust the electric field direction of the composite electric field so that the fiber bodies 9 successively ejected by the nozzle 7 are inserted into the adhesive of the corresponding position accommodating cavity 101 in a direction consistent with the normal direction of the curved surface structure under the action of the composite electric field; in the actual operation process, the fiber bodies 9 can be driven into the adhesive in sections, for example, the fiber bodies 9 on a certain set section of the stepped mold layer 5 are driven into the adhesive at a certain set angle under the action of the composite electric field, and then the composite electric field is adjusted, the direction of the fiber body 9 changes to the preset value, and then it is driven into another adjacent set section, and so on. Figure 5 and Figure 6 As shown;

[0068] Of course, the length of the set segment may be consistent with or inconsistent with the steps of the stepped mold layer 5 ; the stepped mold layer 5 is mainly provided to accommodate the adhesive, thereby fixing the fiber body 9 through the curing of the adhesive.

[0069] Step 6: After the flocking is completed and solidified in all the accommodating cavities 101 on the base layer 10, the base layer 10 is immersed in liquid to remove the graded mold layer 5, and a flocked bioelectric signal monitoring sensor fabric is obtained, such as Figure 8As shown; dry the flocked sensor fabric.

[0070] In actual use, ultraviolet rays can be used to assist in curing the adhesive. Of course, the ultraviolet irradiation requirement can also be integrated into the nozzle 7, and the nozzle 7 sequentially outputs the fiber body 9 and ultraviolet rays at intervals to complete the flocking.

[0071] The adhesive layer 11 is made of a photosensitive resin material, such as polyurethane acrylate, epoxy acrylate, etc., and silver-plated glass microspheres are added to the photosensitive resin material to provide conductive properties.

[0072] The preparation method of silver-coated glass microspheres is as follows:

[0073] (1) Degreasing the surface of a certain amount of hollow glass microspheres using 0.1 mol / L NaOH solution and then washing with deionized water;

[0074] (2) The degreased glass beads were coarsened with 0.4 mol / L HF solution and then washed three times with deionized water;

[0075] (3) The roughened glass microspheres were sensitized with 12 g / L SnCl2;

[0076] (4) The sensitized glass microbeads were placed in a colloidal Pd solution for activation, and then washed with deionized water and dried;

[0077] (5) Prepare a silver ammonia solution using 10-20 g / L AgNO3 solution, 5-10 g / L NaOH solution, an appropriate amount of NH3·H2O, 12-15 mL / L formaldehyde solution, 3-8 g / L polyethylene glycol, and 15 mL of ethanol solution. Place an appropriate amount of the prepared silver ammonia solution into a flask, place glass microspheres into the silver ammonia solution for silver plating, and place the flask in an ultrasonic generator to disperse the glass microspheres through ultrasonic vibration. Control the temperature of the silver plating solution to 0°C for 65-75 minutes. After the silver plating is completed, rinse the glass microspheres with deionized water three times and then dry them in an oven at 80°C.

[0078] In actual preparation, the binder of the photosensitive resin material can be prepared using the following formula:

[0079]

[0080] In the adhesive, the concentration ratio of the silver-plated glass microspheres can be controlled within a range of 30% to 80% as required, so that the adhesive has conductive properties.

[0081] Of course, in actual use, the adhesive that is cured to form the adhesive layer 11 can also be a thermosetting polyurethane solution, to which silver-plated microspheres or particles are added to make it conductive; at this time, the curing process of the adhesive is simultaneously changed to curing by infrared light; that is, infrared light can replace the above-mentioned ultraviolet light and be sprayed out through the nozzle 7.

[0082] The stepped mold layer 5 is a thin film layer made of a Pluronic material with a mass fraction of 30%-50%, and the film is used to surround a plurality of accommodating cavities 101. Since the Pluronic material is a water-soluble material, after the flocking is cured, the stepped mold layer 5 is immersed in clean water and removed. The immersion time can be set to 3 hours. The stepped mold layer 5 is formed by 3D printing.

[0083] The fiber body 9 is a silver-plated polyester fiber with a length of 400-600 microns and a diameter of 15-25 microns.

[0084] The fiber body 9 is made of silver-plated polyester fiber with large bending stiffness. During the electrostatic flocking process, the direction of the fiber body 9 of each layer will be controlled by a real-time adjustable electric field to ensure that the fiber body 9 inserted into the adhesive layer 11 is as perpendicular as possible to the curved surface of the bioelectric signal monitoring sensor fabric base layer 10, so that more fiber bodies 9 can be vertically inserted into the human skin to increase the contact area between the conductive fiber and the human skin, thereby reducing the contact impedance between the two; the length of the fiber body 9 can be controlled within 400 to 600 microns, of which the proportion of the bottom end embedded in the adhesive is more than half, so that even if the fiber body 9 is completely inserted into the skin, it will not exceed 300 microns. The fiber body 9 of this length will not pass through the epidermis of the human skin and cause itching to the human body, thereby effectively ensuring wearing comfort.

[0085] In this embodiment, the polyester fiber may be silver-plated by chemical plating to form the fiber body 9, specifically:

[0086] (1) A certain amount of polyester fiber was ultrasonically cleaned in acetone and ethanol for 15 to 20 minutes and 8 to 12 minutes, respectively, to complete the fiber degreasing step;

[0087] (2) The cleaned and degreased fiber is placed in a 150 g / L to 250 g / L NaOH solution, magnetically stirred at 60 to 70°C for 20 to 40 minutes, then washed with deionized water and dried to complete the roughening step;

[0088] (3) The roughened fibers were placed in a mixed solution of 12 g / L SnCl2 and 15 mL / L HCl and magnetically stirred for 10 min to sensitize the fibers to improve their chemical reactivity. After sensitization, the fibers were washed in deionized water.

[0089] (4) The sensitized fiber was placed in a silver ammonia solution prepared with 3 g / L AgNO3 and an appropriate amount of ammonia water and magnetically stirred for 20 to 30 minutes, and then washed with deionized water;

[0090] (5) preparing a silver ammonia solution using 5-12 g / L AgNO3 solution, 25% ammonia water, 1.5-3.0 g / L NaOH solution, 5-15 g / L glucose solution, and 1 g / L tartaric acid solution, and preparing a reducing solution using 5-20 mL / L ethylenediamine solution, 50-70 mL / L ethanol solution, and 0.36 g / L polyethylene glycol-1000 solution;

[0091] (6) During silver plating, the silver ammonia solution and the reducing solution are mixed in a volume ratio of 1:2. Before silver plating, the pretreated polyester fiber is placed in the reducing solution. During the silver plating process, the silver ammonia solution is added dropwise to the reducing solution. The entire silver plating process is carried out at a room temperature of 18 to 25°C, and the silver plating time is controlled at 30 to 50 minutes.

[0092] (7) The fiber body 9 is manufactured; after the silver plating is completed, the silver-plated polyester fiber is isolated from oxygen and stored to prevent the silver layer from being oxidized.

[0093] The base layer 10 includes a fabric layer woven from conductive yarns, the top surface of the fabric layer is provided with a curved structure, the surface of the curved structure is coated with a conductive adhesive to form an adhesive layer, and the adhesive layer is composed of an epoxy resin with conductive fillers added; of course, the base layer 10 can also be other forms of conductive structures, it can also be a polyurethane material containing conductive particles, which is formed by 3D printing.

[0094] In this embodiment, the conductive yarn can be a metal-plated conductive yarn, and the plated metal material is at least one of silver, copper-nickel, aluminum, zinc, and gold. Considering that the surface metal coating of the conductive yarn will be lost due to friction during the winding process, the thickness and metal content of the metal coating on the yarn surface should be increased as much as possible; it can also be a conductive flexible yarn such as carbon fiber filament, pure silver filament, stainless steel filament, etc.

[0095] The curved fabric layer can be created through the preparation of warp-knitted spacer fabrics or weft-knitted air-layer fabrics. The curvature of the warp-knitted spacer curved fabric is controlled by the number of knitting needles, the number of knitting courses, and the spacer yarn feed rate; the curvature of the weft-knitted air-layer curved fabric is controlled by varying the number of knitting needles and the number of knitting wales.

[0096] The conductive adhesive is mainly used to bond the conductive fabric of the base layer 10 and the stepped mold layer 5 , fixing the stepped mold layer 5 on the conductive fabric, and is also used to bond the conductive fabric and the cured adhesive layer 11 .

[0097] Conductive adhesives are composed of a main component, conductive fillers, toughening agents, solvents, and other additives. Epoxy resin can be used as the main component; there are many types of conductive fillers, such as silver powder, silver-plated copper powder, and silver-plated quartz powder; and toughening agents are generally low-molecular-weight active toughening agents, such as liquid carboxyl-terminated nitrile rubber and low-molecular-weight polyester.

[0098] To use the conductive adhesive, first apply the adhesive (i.e., a well-mixed mixture of epoxy resin, conductive filler, toughening agent, and solvent) evenly to the curved surface of the conductive fabric. A curing agent is then added, and the fabric is placed in a 3D printer to print the stepped mold layer 5 (or, alternatively, print the stepped mold layer 5 first and then bond it to the fabric surface). The adhesive takes a long time to cure at room temperature. After printing the mold layer, while the adhesive is still not fully cured, the prepared photosensitive resin is added to the mold layer for subsequent electrostatic flocking.

[0099] Of course, the flocking fabric of the present application is preferably prepared in a dark, airtight, light-proof container or space.

[0100] The present invention can reliably prepare velvet-type sensing fabrics to effectively increase the contact area with the human body and solve the problem of large contact impedance caused by a small effective contact area. The concept is novel and greatly helps to improve and ensure the quality of bioelectric signals.

[0101] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any modifications may be made within the scope of protection of the present invention.

Claims

1. An electrostatic flocking bioelectrical signal monitoring and sensing fabric preparation system, characterized by: The invention comprises a base layer (10) made of a conductive material, the top surface of the base layer (10) being arranged as a curved surface structure that fits a part of a human body, a stepped mold layer (5) extending from the curved surface structure of the base layer (10), the stepped mold layer (5) being composed of a plurality of accommodating cavities (101) with openings facing upwards, the accommodating cavities (101) being sequentially distributed along the surface of the curved surface structure, and the accommodating cavities (101) containing a conductive adhesive; a nozzle (7) being arranged above the curved surface structure, the nozzle (7) spraying a fiber body (9) downwards toward the accommodating cavity (101), the fiber body (9) being a conductor; and a horizontal electrode plate group (3) arranged in parallel and at intervals above and below the base layer (10), and a vertical electrode plate group (2) arranged in parallel and at intervals on both sides of the base layer (10), wherein the horizontal electrode plate group (3) and the vertical electrode plate group (2) are energized to form a composite electric field.

2. The electrostatic flocking bioelectrical signal monitoring sensor fabric preparation system according to claim 1, characterized in that: The vertical electrode plate group (2) and the horizontal electrode plate group (3) are electrically connected to the steering power supply (1), and the steering power supply (1) changes the voltage value and / or polarity of the vertical electrode plate group (2) and / or the horizontal electrode plate group (3), thereby changing the electric field direction of the composite electric field, and adjusting the posture of the conductive fiber body (9) by changing the electric field force applied to the conductive fiber body (9) in the composite electric field; the nozzle (7) and the base layer (10) are electrically connected to the conductive power supply (8).

3. The electrostatic flocking bioelectrical signal monitoring sensor fabric preparation system according to claim 1, characterized in that: The nozzle (7) is a porous nozzle that can spray both the fiber body (9) and ultraviolet rays. The ultraviolet rays are irradiated toward the accommodating cavity (101). The ultraviolet rays promote the solidification of the adhesive with the fiber body (9) in the accommodating cavity (101) to form an adhesive layer (11).

4. The electrostatic flocking bioelectrical signal monitoring sensor fabric preparation system according to claim 3, characterized in that: The structure of the nozzle (7) is as follows: it includes a nozzle body (71), a UV light outlet (73) is connected to the middle of the bottom surface of the nozzle body (71), and a UV light inlet (77) is provided on the side of the nozzle body (71). An external UV light source (4) is incident into the nozzle body (71) through the UV light inlet (77), and is deflected by a reflector (75) and emitted downward from the downward-facing UV light outlet (73); a plurality of fiber outlets (72) are further provided on the bottom surface of the nozzle body (71) located outside the circumference of the UV light outlet (73), and a single fiber outlet (72) is connected to a fiber inlet (76) provided on the top surface of the nozzle body (71) through a fiber channel (74); and the fiber inlet (76) is connected to an external fiber pumping device.

5. The electrostatic flocking bioelectrical signal monitoring sensor fabric preparation system according to claim 1, characterized in that: It also includes a power mechanism for driving the nozzle (7) to move, the power mechanism drives the nozzle (7) to move along the moving track (6) in a horizontal plane, so that the nozzle (7) is located directly above the corresponding accommodating cavity (101).

6. A method for preparing an electrostatic flocking bioelectrical signal monitoring sensor fabric based on the preparation system of claim 1, characterized in that: The steps include: A base layer (10) is prepared to fit the curved surface of a specific part of the human body, and a stepped mold layer (5) is formed on the curved surface structure of the base layer (10) by 3D printing; Pour the adhesive into the corresponding accommodating cavity (101) of the stepped mold layer (5); The horizontal electrode plate group (3) and the vertical electrode plate group (2) are electrically connected to form a composite electric field, and the electric field direction of the composite electric field is adjusted to a preset direction; the fiber body (9) is sprayed into the corresponding accommodation cavity (101) by the nozzle (7) to perform flocking; The fiber body (9) adjusts its posture under the action of the composite electric field and is inserted into the adhesive in the normal direction of the curved surface structure at the corresponding accommodation cavity (101), and forms an adhesive layer (11) as the adhesive solidifies; The voltages of the horizontal electrode plate group (3) and the vertical electrode plate group (2) are adjusted, and the electric field direction of the composite electric field is adjusted so that the fiber bodies (9) successively ejected through the nozzle (7) are inserted into the adhesive of the corresponding position accommodating cavity (101) in a direction consistent with the normal direction of the curved surface structure under the action of the composite electric field; after the flocking in all the accommodating cavities (101) on the base layer (10) is completed and solidified, the base layer (10) is immersed in liquid to remove the stepped mold layer (5), thereby obtaining a flocked bioelectric signal monitoring sensor fabric; and the flocked sensor fabric is dried.

7. The method for preparing an electrostatic flocking bioelectric signal monitoring sensor fabric according to claim 6, characterized in that: The adhesive layer (11) is made of photosensitive resin material, and glass microspheres with silver-plated surfaces are added to the photosensitive resin material to provide conductive properties.

8. The method for preparing an electrostatic flocking bioelectric signal monitoring sensor fabric according to claim 6, characterized in that: The stepped mold layer (5) is a thin film layer made of a Pluronic material with a mass fraction of 30%-50%, and a plurality of accommodating cavities (101) are formed by the thin film; after flocking is cured, the stepped mold layer (5) is immersed in clean water and removed; the stepped mold layer (5) is formed by 3D printing.

9. The method for preparing an electrostatic flocking bioelectric signal monitoring sensor fabric according to claim 6, characterized in that: The fiber body (9) is a silver-plated polyester fiber with a length of 400-600 microns and a diameter of 15-25 microns.

10. The method for preparing an electrostatic flocking bioelectric signal monitoring sensor fabric according to claim 6, characterized in that: The base layer (10) comprises a fabric layer woven from conductive yarns, the top surface of the fabric layer is provided with a curved surface structure, the surface of the curved surface structure is coated with a conductive adhesive to form an adhesive layer, and the adhesive layer is composed of epoxy resin added with conductive fillers.

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