Wearable sweat amount detection device and preparation method, equipment and application thereof

Abstract

The invention discloses a wearable sweat amount detection device as well as a preparation method, equipment and application thereof. The wearable sweat amount detection device comprises a plurality of stacking units, each stacking unit comprises an insulating hydrophilic sweat storage layer and a hydrophobic sweat blocking layer which are stacked in sequence, and each stacking unit is provided with a sweat permeation channel; first perspiration sensing electrode layers or second perspiration sensing electrode layers are alternately arranged between the adjacent laminated units, the multiple first perspiration sensing electrode layers are electrically conducted to form a first electrode array, and the multiple second perspiration sensing electrode layers are electrically conducted to form a second electrode array. The perspiration mode of sweat is controlled through the hydrophilic and hydrophobic gradient design of different porous materials, meanwhile, the detection of the perspiration rate and the perspiration amount of a human body is achieved through the embedded interlayer interdigital electrodes, and the breathable and sweat-permeable sweat-permeable underwear has the advantages of being breathable, sweat-permeable and comfortable to wear; meanwhile, based on the construction of the multilayer hydrophilic-hydrophobic structure, the sweat amount can be accurately calculated by utilizing a sudden change curve of the conductivity, and the synchronous improvement of the air permeability and the accuracy is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of wearable sensor devices, and in particular to a wearable sweat volume detection device, a preparation method, a device and an application thereof. Background Art

[0002] The evolving wearable devices aim to address the limitations of centralized, passive healthcare by giving individuals a deep understanding of their own physiological dynamics, and are leading the development of personalized, predictive, and preventive healthcare. It is well known that human body fluids such as blood, tears, urine, saliva, sweat, etc. can largely reflect the health of the human body, but most of them have limitations in wearable sensing. In contrast, sweat can be generated on demand in a non-invasive manner at a convenient location on the body, which is very suitable for continuous monitoring and shows great application prospects in wearable sensing.

[0003] Studies have shown that sweat discharge can take away a large amount of accumulated heat in the body and is one of the important ways for the human body to maintain core temperature. However, if a large amount of sweat is not replenished in time, the human body will experience varying degrees of dehydration, which will cause water and salt metabolism disorders, decreased exercise capacity, and damage to body organs. In severe cases, there is a risk of shock or even death. Therefore, if a wearable sweat volume detection device can be used to monitor the amount of sweat produced during exercise, early identification and warning of dehydration can be achieved, thereby avoiding the damage to human health caused by dehydration. This is particularly important for human health, especially the life and health of special groups such as athletes, soldiers, and firefighters.

[0004] At present, various forms of wearable sweat monitoring devices have been reported, but they still face some challenges in practical applications. For example, one type is a flexible sweat sensor based on microfluidics, among which most microfluidic devices are made of materials such as polydimethylsiloxane (PDMS) that are not breathable and permeable to sweat, which will cause discomfort when worn for a long time and even change the microenvironment of the human epidermis, causing skin inflammation and other problems; another type is a patch sensor based on colorimetry, whose accuracy depends on the human body's perception of color, and has a large error in sweat detection.

[0005] It can be seen that in wearable sweat monitoring devices, air permeability and measurement accuracy are often contradictory, and it is difficult to obtain high measurement accuracy while achieving high air permeability and maintaining wearing comfort. Summary of the invention

[0006] In view of the deficiencies in the prior art, the object of the present invention is to provide a wearable sweat volume detection device, a preparation method, an apparatus and an application thereof.

[0007] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes: In a first aspect, the present invention provides a wearable sweat amount detection device having a laminated hydrophilic-hydrophobic gradient structure, comprising a plurality of laminated units laminated along a selected direction, any of the laminated units comprising an insulating hydrophilic sweat storage layer and a hydrophobic sweat blocking layer laminated in sequence along the selected direction, and having a sweat permeation channel penetrating along the selected direction, and the sweat permeation channel continuously extending between the plurality of the laminated units; In the insulating hydrophilic sweat storage layer, the inner surface of the sweat permeation channel has a hydrophilic property, and in the hydrophobic sweat blocking layer, the inner surface of the sweat permeation channel has a hydrophobic property; Along the selected direction, a series of positions between adjacent stacked units are alternately provided with the first sweat sensing electrode layer or the second sweat sensing electrode layer, so that the first sweat sensing electrode layer and the second sweat sensing electrode layer form an interdigitated electrode structure, and the multiple layers of the first sweat sensing electrode layers are electrically connected to form a first electrode array, and the multiple layers of the second sweat sensing electrode layers are electrically connected to form a second electrode array.

[0008] In a second aspect, the present invention further provides a wearable sweat amount detection device having a laminated hydrophilic-hydrophobic gradient structure, which comprises the above-mentioned wearable sweat amount detection device and an electrical detection unit; The electrical detection unit is electrically connected to the first electrode array and the second electrode array respectively to detect a change in electrical conductivity between the first electrode array and the second electrode array.

[0009] In a third aspect, the present invention further provides a wearable sweat amount detection method based on a laminated hydrophilic-hydrophobic gradient structure, wherein the wearable sweat amount detection method is applied to the above-mentioned wearable sweat amount detection device, comprising: measuring electrical conductivity between the first electrode array and the second electrode array; Based on the numerical value of the electrical conductivity and the curve mutation, the penetration depth of sweat in the multi-layer stacking unit is determined to calculate the amount of sweat.

[0010] In a fourth aspect, the present invention also provides a method for preparing the wearable sweat amount detection device, which comprises: Providing sweat-sensing electrode films; A porous insulating hydrophilic sweat storage layer and a hydrophobic sweat blocking layer are prepared at one time on the surface of the sweat-transmitting sensor electrode film by electrospinning to form a detection unit; Multiple detection units are stacked and combined, and the odd-numbered sweat sensing electrode films arranged in a selected direction are electrically connected to form a first electrode array composed of multiple first sweat sensing electrode layers, and the even-numbered sweat sensing electrode films are electrically connected to form a second electrode array composed of multiple second sweat sensing electrode layers.

[0011] Based on the above technical solution, compared with the prior art, the beneficial effects of the present invention at least include: A flexible wearable sweat amount detection device with a laminated hydrophilic-hydrophobic gradient structure proposed in the present invention can control the permeation mode of sweat through the hydrophilic-hydrophobic gradient design of different porous materials, and at the same time, through the embedded interlayer interdigitated electrodes, realize the detection of human sweat rate and sweat amount, thereby realizing the monitoring of human dehydration status and reducing health risks; the flexible wearable sweat amount detection device can be made into a small wearable detection device such as a bracelet, a patch, or even embedded in a fabric, which has the advantages of being breathable and sweat-permeable and comfortable to wear. At the same time, based on the construction of a multi-layer hydrophilic-hydrophobic structure, the sudden change curve of the conductive capacity can be used to accurately calculate the sweat amount, thereby achieving a simultaneous improvement in breathability and accuracy, and solving the existing technical problems.

[0012] The above description is only an overview of the technical solution of the present invention. In order to enable those skilled in the art to more clearly understand the technical means of the present application and implement them according to the contents of the specification, the following is a description of the preferred embodiments of the present invention in conjunction with detailed drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic cross-sectional structure diagram of a wearable sweat volume detection device provided by a typical implementation case of the present invention; Figure 2 It is a schematic diagram of the planar structure of a wearable sweat volume detection device provided by a typical implementation case of the present invention; Figure 3a This is a contact angle test diagram of a hydrophilic layer and a hydrophobic layer of a flexible wearable sweat detection device provided in a typical embodiment of the present invention; Figure 3b This is a test chart of the time required for water penetration into the hydrophilic layer and the hydrophobic layer of the flexible wearable sweat detection device provided by a typical embodiment of the present invention; Figure 4 Schematic diagram of the sensing principle of a flexible wearable sweat volume detection device provided by a typical implementation case of the present invention; Figure 5 It is a graph of conductivity signals of a flexible wearable sweat volume detection device provided in a typical embodiment of the present invention when detecting different simulated sweat flow rates during a simulated test under microfluidic injection pump test conditions; Figure 6 This is a curve diagram of the corresponding relationship between sweating speed and filling time of a flexible wearable sweat detection device provided in a typical implementation case of the present invention, which is simulated under microfluidic injection pump test conditions.

[0014] Explanation of the reference numerals: 1. human skin; 210. first electrode array; 211. first sweat-sensing electrode layer; 220. second electrode array; 221. second sweat-sensing electrode layer; 30. insulating hydrophilic sweat storage layer; 31. first insulating hydrophilic sweat storage layer; 40. hydrophobic sweat-blocking layer; 41. first hydrophobic sweat-blocking layer; 5. porous adhesive layer. DETAILED DESCRIPTION

[0015] Existing sweat sensors, when meeting the requirements of high-precision measurement, are very likely to cause discomfort when worn for a long time, have closed sweat pores, poor air permeability and sweat permeability, and may even change the microenvironment of the human epidermis, causing skin inflammation and other problems. In view of the deficiencies in the prior art, the inventors of this case have proposed the technical solution of the present invention after long-term research and extensive practice.

[0016] The main purpose of the present invention is to provide a flexible wearable sweat detection device with a laminated hydrophilic-hydrophobic gradient structure, which will not cover the sweat pores of the skin, has excellent air permeability and sweat permeability, and will not change the human epidermal microenvironment, thereby protecting the skin from inflammation. It is comfortable to wear and is used to overcome the problems existing in the prior art. The technical solution, its implementation process and principle will be further explained as follows.

[0017] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0018] Moreover, relational terms such as “first” and “second” are merely used to distinguish one component or method step from another with the same name, but do not necessarily require or imply any such actual relationship or order between these components or method steps.

[0019] An embodiment of the present invention provides a wearable sweat amount detection device with a laminated hydrophilic-hydrophobic gradient structure (hereinafter referred to as the device), which includes a plurality of laminated units laminated along a selected direction, any of the laminated units includes an insulating hydrophilic sweat storage layer and a hydrophobic sweat blocking layer laminated in sequence along the selected direction, and has a sweat permeation channel running through along the selected direction, and the sweat permeation channel extends continuously between the plurality of laminated units; in the insulating hydrophilic sweat storage layer, the inner surface of the sweat permeation channel has a hydrophilic property, and in the hydrophobic sweat blocking layer, the inner surface of the sweat permeation channel has a hydrophobic property; along the selected direction, a series of positions between adjacent laminated units are alternately provided with a first sweat permeation sensing electrode layer or a second sweat permeation sensing electrode layer, so that the first sweat permeation sensing electrode layer and the second sweat permeation sensing electrode layer form an interdigitated electrode structure, and the plurality of first sweat permeation sensing electrode layers are electrically connected to form a first electrode array, and the plurality of second sweat permeation sensing electrode layers are electrically connected to form a second electrode array.

[0020] As some typical examples of the above-mentioned overall technical solution, the flexible wearable sweat amount detection device with a laminated hydrophilic-hydrophobic gradient structure provided by the embodiments of the present invention may include: The layered interdigitated electrodes include a first electrode array composed of a plurality of sweat sensing electrode layers arranged in odd-numbered layers and a second electrode array composed of a plurality of sweat sensing electrode layers arranged in even-numbered layers, and are used to transmit signals. The specific signal transmission method can be conductivity, resistance, or current measured by applying a constant voltage, or various other methods that can reflect the conductivity between the first electrode array and the second electrode array.

[0021] Multiple insulating hydrophilic sweat storage layers are hydrophilic and serve as insulating layers between two adjacent electrode layers, and are also used to collect and store a fixed volume of sweat; multiple hydrophobic sweat blocking layers are hydrophobic and produce a certain resistance to the transfer of sweat to the next stacking unit, ensuring that the insulating hydrophilic sweat storage layer can be filled with sweat to a set capacity; the insulating hydrophilic sweat storage layer and the hydrophobic sweat blocking layer constitute a stacking unit with a hydrophilic-hydrophobic gradient, which is arranged between two adjacent sweat-permeable sensing electrode layers, insulates the two adjacent first electrode arrays and the second electrode arrays, and forms an interlayer interdigitated electrode structure that is not connected in an initial state.

[0022] A plurality of tightly interfaced laminated units composed of the sweat-permeable sensing electrode layer, the insulating hydrophilic sweat storage layer, and the hydrophobic sweat-blocking layer form sweat-permeable channels for continuous permeation of sweat in a selected direction. When sweat passes through the first sweat-permeable sensing electrode layer, the first insulating hydrophilic sweat storage layer is filled to a preset capacity under the resistance of the hydrophobic sweat-blocking layer. Then, further filling of sweat causes the solution pressure to exceed the resistance of the first hydrophobic sweat-blocking layer, thereby breaking through the first hydrophobic sweat-blocking layer and contacting the second sweat-permeable sensing electrode layer. Since sweat containing conductive ions is conductive, after the first insulating hydrophilic sweat storage layer is filled with sweat, a conductive path is formed between the upper and lower adjacent sweat-permeable sensing electrode layers (i.e., the first and second layers), and the electrical conductor of the overall detection circuit undergoes a sudden change.

[0023] As sweat continues to form, it continues to penetrate due to pressure. When the sweat fills and conducts the second and third perspiration sensing electrode layers, the conduction path between the first electrode array and the second electrode array increases by one), and a second conductivity mutation occurs accordingly. Therefore, by combining the conductivity mutation curve (especially the number of curve mutations since the beginning; the specific conductance value can also be used to assist in verifying the number of curve mutations), it is possible to accurately know which layer the sweat has penetrated, so that the sweat discharge rate can be accurately calculated; at the same time, since each layer structure adopts a breathable structure, the breathability problem caused by the existing high-precision sweat detection device and method is avoided.

[0024] The above content is an overall introduction to the structure and principle of the device provided by the present invention. As for some specific material details, in some embodiments, the first sweat sensing electrode layer and the second sweat sensing electrode layer contain a first hydrophilic and hydrophobic material and have a first pore structure; the insulating hydrophilic sweat storage layer contains a second hydrophilic and hydrophobic material and has a second pore structure; the hydrophobic sweat blocking layer contains a third hydrophilic and hydrophobic material and has a third pore structure; the first hydrophilic and hydrophobic material, the second hydrophilic and hydrophobic material and the third hydrophilic and hydrophobic material are tightly fitted so that the first pore structure, the second pore structure and the third pore structure are interconnected.

[0025] More specifically, in some embodiments, the water contact angle of the first hydrophilic and hydrophobic material is less than 90°, in some embodiments, the water contact angle of the second hydrophilic and hydrophobic material is less than 90°, and in some embodiments, the water contact angle of the third hydrophilic and hydrophobic material is greater than 90°.

[0026] In addition, regarding size parameters, in some embodiments, the pore size of the first pore structure is 0.05-0.5 mm; in some embodiments, the pore size of the second pore structure is 0.0001-0.01 mm; in some embodiments, the pore size of the third pore structure is 0.001-0.05 mm.

[0027] In some embodiments, the thickness of the first sweat sensing electrode layer and / or the second sweat sensing electrode layer is 0.001-0.05 mm; in some embodiments, the thickness of the insulating hydrophilic sweat storage layer is 0.1-0.5 mm; in some embodiments, the thickness of the hydrophobic sweat blocking layer is 0.005-0.05 mm.

[0028] Of course, it should be noted that the above-mentioned material characteristics and size characteristics are representative ranges summarized by the inventors of the present invention during the research and development process, and mainly play a certain exemplary role, but it does not mean that the functions and effects of the present invention cannot be achieved at all beyond the above-mentioned range. Whether it belongs to the feasible implementation scope revealed by the present invention should still be limited to the overall structure / functional characteristics and principles indicated by the present invention.

[0029] In terms of specific structural design, in some embodiments, in plane projection, the first sweat sensing electrode layer and the second sweat sensing electrode layer are arranged in the first area, the insulating hydrophilic sweat storage layer is arranged in the second area, and the hydrophobic sweat blocking layer is arranged in the third area, and at least parts of the first area, the second area and the third area overlap.

[0030] In some embodiments, the first region, the second region, and the third region preferably completely overlap.

[0031] In order to assemble each stacking unit, in some embodiments, the device may further include a porous adhesive layer, which is arranged between two adjacent stacking units and has edges protruding from the stacking units, and the edge protruding areas of multiple porous adhesive layers are bonded to each other.

[0032] In some embodiments, the porous adhesive layer has a pore size of 0.01-1 mm and a thickness of 0.001-0.05 mm.

[0033] As a typical example, the porous adhesive layer is arranged between the adjacent laminated units, so that the multiple laminated units are tightly bonded to each other. The area of ​​the porous adhesive layer is slightly larger than the laminated unit, so that the edges of the porous adhesive layer are adhered to each other, the laminated unit is sealed, and sweat cannot overflow from the edge. The porous adhesive layer not only serves as an adhesive layer between layers, but also uses the protruding edge as the surrounding packaging layer of the device, playing multiple roles. In the preferred design, the sweat-sensing electrode layer, the insulating hydrophilic sweat storage layer, the hydrophobic sweat-blocking layer, and the porous adhesive layer are all flexible.

[0034] A second aspect of an embodiment of the present invention also provides a wearable sweat amount detection device having a laminated hydrophilic-hydrophobic gradient structure, which includes a wearable sweat amount detection device provided in any of the above embodiments and an electrical detection unit; the electrical detection unit is respectively connected to the first electrode array and the second electrode array to detect the change in conductivity between the first electrode array and the second electrode array.

[0035] Correspondingly, the present invention also provides a wearable sweat amount detection method based on a laminated hydrophilic-hydrophobic gradient structure. The wearable sweat amount detection method is applied to a wearable sweat amount detection device provided in any of the above embodiments, and comprises the following steps: measuring electrical conductivity between the first electrode array and the second electrode array; Based on the numerical value of the electrical conductivity and the curve mutation, the penetration depth of sweat in the multi-layer stacking unit is determined to calculate the amount of sweat.

[0036] As a typical example, electrical detection instruments and equipment, such as an LCR meter, or a miniaturized wearable detection device can be used to connect the two interdigitated electrode pins of the sweat sensing electrode layer, and perform necessary insulation treatment on the electrode connections to prevent circuit short-circuiting, thereby detecting changes in conductivity between the electrode arrays during human movement, and calculating the sweat amount and average sweat rate based on the fixed capacity of the insulating hydrophilic sweat storage layer and the test time.

[0037] In addition, in order to obtain the above-mentioned device, an embodiment of the present invention also provides a method for preparing the wearable sweat amount detection device provided in any of the above-mentioned embodiments, which comprises the following steps: Providing sweat-sensing electrode films; A porous insulating hydrophilic sweat storage layer and a hydrophobic sweat blocking layer are prepared at one time on the surface of the sweat-transmitting sensor electrode film by electrospinning to form a detection unit; Multiple detection units are stacked and combined, and the odd-numbered sweat sensing electrode films arranged in a selected direction are electrically connected to form a first electrode array composed of multiple first sweat sensing electrode layers, and the even-numbered sweat sensing electrode films are electrically connected to form a second electrode array composed of multiple second sweat sensing electrode layers.

[0038] The technical solution of the present invention is further described in detail below through several embodiments and in conjunction with the accompanying drawings. However, the selected embodiments are only used to illustrate the present invention, and do not limit the scope of the present invention.

[0039] Example 1 The embodiment of the present invention illustrates the material combination and specific structure of a flexible wearable sweat amount detection device. The copper-nickel conductive non-woven fabric, PA66, formic acid, PU, ​​DMF, PET double-sided tape, etc. used are all known to those skilled in the art and can be purchased commercially.

[0040] See also Figure 1 and Figure 2 A flexible wearable sweat volume detection device with a laminated hydrophilic-hydrophobic gradient structure is attached to human skin 1, comprising: a layered interdigitated electrode, comprising a first electrode array 210 composed of a plurality of odd-numbered first sweat-sensing electrode layers 211 and a second electrode array 220 composed of a plurality of even-numbered second sweat-sensing electrode layers 221, for transmitting signals; a plurality of insulating hydrophilic sweat storage layers 30, which are hydrophilic and serve as insulating layers between two adjacent electrode layers, and are also used to collect and store a fixed volume of sweat; a plurality of hydrophobic sweat blocking layers 40, which are hydrophobic and produce a certain resistance to the transfer of sweat to the next laminated unit, so as to ensure that the insulating hydrophilic sweat storage layer 30 can be filled with sweat to a set capacity; the insulating hydrophilic sweat storage layer 30 and the hydrophobic sweat blocking layer 40 form a laminated unit with a hydrophilic-hydrophobic gradient, which is arranged between two adjacent sweat-sensing electrode layers, connecting the two adjacent first electrode arrays 210 and the second electrode arrays The row 220 is insulated to form interlayer interdigitated electrodes that are not connected in the initial state; a plurality of tightly interfaced laminated units composed of the first sweat-permeable sensing electrode layer 211, the insulating hydrophilic sweat storage layer 30, and the hydrophobic sweat-blocking layer 40 form sweat-permeable channels for continuous permeation of sweat along a selected direction; sweat passes through the first sweat-permeable sensing electrode layer 211, and fills the first insulating hydrophilic sweat storage layer 31 to a preset capacity under the resistance of the first hydrophobic sweat-blocking layer 41, and then further filling of sweat causes the solution pressure to exceed the resistance of the first hydrophobic sweat-blocking layer 41, and then breaks through the first hydrophobic sweat-blocking layer 41, and contacts the first second sweat-permeable sensing electrode layer 221; because sweat containing conductive ions is conductive, after the first insulating hydrophilic sweat storage layer 31 is filled with sweat, a conductive path is formed between the upper and lower adjacent sweat-permeable sensing electrode layers, and the conductance value (or resistance value, which is the inverse of conductance) of the overall detection circuit suddenly changes.

[0041] The sweat-permeable sensing electrode layers are porous conductive non-woven fabrics with sweat-permeable properties interwoven with conductive fibers. The conductive fibers are polyester fibers with copper and nickel deposited on the surface, which have good conductive properties. The diameter of the conductive fibers is 0.001-0.05mm; the sweat-permeable sensing electrode layer is in the shape of a rectangular film with pins of 1-20mm in length and 1-20mm in width, and the pins are in the shape of a rectangle of 5-20mm in length and 1-5mm in width; to facilitate the penetration of sweat, the sweat-permeable sensing electrode layer has a thickness of 0.005-0.05mm and a pore size of 0.05-0.5mm. It is also hydrophilic and has a contact angle of less than 90°.

[0042] The insulating hydrophilic sweat storage layer 30 is a hydrophilic porous fabric interwoven with insulating fibers, or is a porous fabric interwoven with insulating fibers and then subjected to hydrophilic treatment to obtain hydrophilicity; specifically, the insulating hydrophilic sweat storage layer 30 is a PA66 porous membrane in situ electrospun on the sweat sensing electrode layer by electrospinning; the insulating hydrophilic sweat storage layer 30 has a thickness of 0.1-0.5 mm, a pore size of 0.0001-0.01 mm, a rectangular shape of 1-20 mm in length and 1-20 mm in width, is hydrophilic, and has a contact angle of less than 90°.

[0043] The hydrophobic sweat-blocking layer 40 is a hydrophobic porous fabric interwoven with insulating fibers; specifically, the hydrophobic sweat-blocking layer 40 is a PU porous membrane electrospun in situ on the insulating hydrophilic sweat storage layer 30 by electrospinning; the hydrophobic sweat-blocking layer 40 has a thickness of 0.005-0.05 mm, a pore size of 0.001-0.05 mm, and a shape of a rectangle with a length of 1-20 mm and a width of 1-20 mm. It is hydrophobic and has a contact angle greater than 90°.

[0044] The porous adhesive layer 5 is arranged between the adjacent laminated units to make the laminated units closely bonded to each other. Specifically, the porous adhesive layer 5 is a PET double-sided adhesive with holes, such as Figure 2 As shown, its area is slightly larger than the laminated unit, so that the edges of the porous adhesive layer 5 stick to each other, the laminated unit is closed, and sweat cannot overflow from the edge; the porous adhesive layer 5 has a pore size of 0.01-1mm and a thickness of 0.001-0.05mm.

[0045] In this embodiment, the insulating hydrophilic sweat storage layer 30 and the hydrophobic sweat blocking layer 40 are both prepared on the sweat sensing electrode layer by an in-situ electrospinning method, and have good interface bonding, and there is no need to use PET double-sided tape for interface optimization. The PET double-sided tape is only arranged between the stacked units consisting of a single first sweat sensing electrode layer 211 (or a second sweat sensing electrode layer 221), a single first insulating hydrophilic sweat storage layer 31, and a single first hydrophobic sweat blocking layer 41.

[0046] Continue as Figure 2 As shown, the orthographic projections formed by the two sweat-transmitting sensing electrode layers, the insulating hydrophilic sweat storage layer 30, and the hydrophobic sweat-blocking layer 40 along the selected direction almost completely overlap.

[0047] In practical applications, a laminated unit consisting of a single layer of the first sweat-transmitting sensing electrode layer 211, a first insulating hydrophilic sweat storage layer 31, and a first hydrophobic sweat-blocking layer 41 has a hydrophilic-hydrophobic gradient structure to achieve control of the permeation mode of sweat in the sweat-transmitting channel; specifically, Figure 3a As shown in the figure, the contact angle of the PA66 porous membrane is 29°, and the contact angle of the conductive non-woven fabric is 32°, both of which are much smaller than 90°, and have good hydrophilicity. The contact angle of the PU porous membrane is 128°, which is greater than 90°, and has hydrophobicity, thereby forming an effective hydrophilic-hydrophobic gradient structure; further, the difficulty of sweat penetration from the hydrophilic side and the hydrophobic side of the laminated unit is different, as shown in the figure below. Figure 3b As shown, the solution can penetrate into the laminated unit from the hydrophilic side of the laminated unit in less than 1 second, and the solution needs 7 seconds to penetrate into the laminated unit from the hydrophobic side of the laminated unit, which shows that the hydrophilic-hydrophobic gradient structure can control the difficulty of sweat penetration, thereby achieving the expected effects of the sweat sensing electrode layer, the insulating hydrophilic sweat storage layer 30, and the single-layer hydrophobic sweat-blocking layer 40.

[0048] like Figure 4 As shown, when sweat passes through the first sweat-transmitting sensing electrode layer 211 and enters the first insulating hydrophilic sweat storage layer 31, the total conductance of the device hardly changes; the sweat gradually fills the first insulating hydrophilic sweat storage layer 31, and under the resistance of the first hydrophobic sweat-blocking layer 41, the sweat cannot contact the second sweat-transmitting sensing electrode layer 221 before filling the first insulating hydrophilic sweat storage layer 31, and the total conductance of the device still hardly changes; when the first insulating hydrophilic sweat storage layer 31 is filled, the sweat continues to increase, generating a certain pressure, breaking through the first hydrophobic sweat-blocking layer 41, and contacting the second sweat-transmitting sensing electrode layer 221. When the two layers 221 are in contact, the total conductance of the device suddenly changes, and changes continuously to form a slope line as the contact area increases; the sweat continues to fill the next insulating hydrophilic sweat storage layer 30, and the total conductance of the device hardly changes; then the sweat breaks through the hydrophobic sweat barrier layer 40 again, causing the total conductance of the device to suddenly change, and this cycle repeats to form a conductivity step change curve similar to the one in the figure. The step change can be used to clearly know where the sweat has diffused, and by establishing the relationship between the sweat storage amount of the insulating hydrophilic sweat storage layer 30 and the average sweating rate, the average sweating rate and sweating amount can be obtained.

[0049] like Figure 5 and Figure 6 As shown in Figure 2, different device conductance change curves were obtained under different simulated sweat flow rates. Figure 4The ideal conductivity change curve in the schematic diagram shown in FIG. 1 is very similar; further, since the time interval between the two conductivity mutations is the time for each insulating hydrophilic sweat storage layer 30 to be filled, the conductivity change curve is established Figure 6 The relationship between sweat flow rate and the average filling time of each layer can be used to calculate the sweat rate and sweat amount of the human body based on the time interval between two mutations of the conductivity curve.

[0050] Example 2 This embodiment illustrates the preparation process of the device provided in Example 1, which is specifically as follows: (1) Prepare a porous conductive network film formed by interweaving polyester fibers with copper and nickel deposited on the surface. Preferably, the porous conductive network film is about the size of A4 paper to facilitate later cutting; (2) In situ electrospinning a PA66 porous hydrophilic fiber membrane on the porous network film by an electrospinning method; (3) In situ electrospinning a PU porous hydrophobic fiber membrane on the PA66 porous hydrophilic fiber membrane again by an electrospinning method to obtain a large-area fiber with a laminated hydrophilic-hydrophobic gradient structure; (4) Cut the large-area fiber membrane into laminated units of a desired size by laser cutting or other cutting methods; (5) Assemble the laminated units into a wearable sweat detection device by using a PET double-sided tape with holes.

[0051] Based on the above test results, it can be clearly seen that a flexible wearable sweat amount detection device with a laminated hydrophilic-hydrophobic gradient structure proposed in an embodiment of the present invention can control the permeation mode of sweat through the hydrophilic-hydrophobic gradient design of different porous materials, and at the same time, through the embedded interlayer interdigitated electrodes, it can realize the detection of human sweat rate and sweat amount, thereby realizing the monitoring of human dehydration status and reducing health risks; the flexible wearable sweat amount detection device can be made into a small wearable detection device such as a bracelet, a patch, or even embedded in a fabric, which has the advantages of being breathable and sweat-permeable and comfortable to wear. At the same time, based on the construction of a multi-layer hydrophilic-hydrophobic structure, the sudden change curve of the conductive capacity can be used to accurately calculate the sweat amount, thereby achieving the simultaneous improvement of breathability and accuracy, and solving the existing technical problems.

[0052] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A wearable sweat volume detection device having a laminated hydrophilic-hydrophobic gradient structure, characterized in that: The invention comprises a plurality of stacked units stacked in a selected direction, wherein any of the stacked units comprises an insulating hydrophilic sweat storage layer and a hydrophobic sweat blocking layer stacked in sequence in the selected direction, and has a sweat permeation channel running through the selected direction, and the sweat permeation channel continuously extends between the plurality of stacked units; In the insulating hydrophilic sweat storage layer, the inner surface of the sweat permeation channel has a hydrophilic property, and in the hydrophobic sweat blocking layer, the inner surface of the sweat permeation channel has a hydrophobic property; Along the selected direction, a series of positions between adjacent stacked units are alternately provided with the first sweat sensing electrode layer or the second sweat sensing electrode layer, so that the first sweat sensing electrode layer and the second sweat sensing electrode layer form an interdigitated electrode structure, and the multiple layers of the first sweat sensing electrode layers are electrically connected to form a first electrode array, and the multiple layers of the second sweat sensing electrode layers are electrically connected to form a second electrode array.

2. The wearable sweat volume detection device according to claim 1, characterized in that: The first perspiration sensing electrode layer and the second perspiration sensing electrode layer comprise a first hydrophilic and hydrophobic material and have a first pore structure; the insulating hydrophilic sweat storage layer comprises a second hydrophilic and hydrophobic material and has a second pore structure; the hydrophobic sweat blocking layer comprises a third hydrophilic and hydrophobic material and has a third pore structure; The first hydrophilic and hydrophobic material, the second hydrophilic and hydrophobic material and the third hydrophilic and hydrophobic material are closely attached to each other so that the first pore structure, the second pore structure and the third pore structure are interconnected.

3. The wearable sweat volume detection device according to claim 2, characterized in that: The water contact angle of the first hydrophilic and hydrophobic material is less than 90°, and / or the water contact angle of the second hydrophilic and hydrophobic material is less than 90°, and / or the water contact angle of the third hydrophilic and hydrophobic material is greater than 90°; and / or, the pore size of the first pore structure is 0.05-0.5 mm; and / or, the pore size of the second pore structure is 0.0001-0.01 mm; and / or, the pore size of the third pore structure is 0.001-0.05 mm; And / or, the thickness of the first sweat sensing electrode layer and / or the second sweat sensing electrode layer is 0.001-0.05mm; and / or, the thickness of the insulating hydrophilic sweat storage layer is 0.1-0.5mm; and / or, the thickness of the hydrophobic sweat blocking layer is 0.005-0.05mm.

4. The wearable sweat volume detection device according to claim 1, characterized in that: In plane projection, the first sweat sensing electrode layer and the second sweat sensing electrode layer are arranged in the first area, the insulating hydrophilic sweat storage layer is arranged in the second area, and the hydrophobic sweat blocking layer is arranged in the third area. At least parts of the first area, the second area and the third area overlap.

5. The wearable sweat volume detection device according to claim 4, characterized in that: The first area, the second area and the third area completely overlap.

6. The wearable sweat volume detection device according to claim 1, characterized in that: It also includes a porous adhesive layer, which is arranged between two adjacent stacking units and has edges protruding from the stacking units. The edge protruding areas of the plurality of porous adhesive layers are bonded to each other.

7. The wearable sweat volume detection device according to claim 6, characterized in that: The porous adhesive layer has a pore size of 0.01-1 mm and a thickness of 0.001-0.05 mm.

8. A wearable sweat volume detection device having a laminated hydrophilic-hydrophobic gradient structure, characterized in that: A wearable sweat detection device comprising any one of claims 1 to 7 and an electrical detection unit; The electrical detection unit is electrically connected to the first electrode array and the second electrode array respectively to detect a change in electrical conductivity between the first electrode array and the second electrode array.

9. A wearable sweat volume detection method based on a laminated hydrophilic-hydrophobic gradient structure, characterized in that: The wearable sweat amount detection method is applied to the wearable sweat amount detection device according to any one of claims 1 to 7, comprising: measuring electrical conductivity between the first electrode array and the second electrode array; Based on the numerical value of the electrical conductivity and the curve mutation, the penetration depth of sweat in the multi-layer stacking unit is determined to calculate the amount of sweat.

10. The method for preparing the wearable sweat volume detection device according to any one of claims 1 to 7, characterized in that: include: Providing sweat-sensing electrode films; A porous insulating hydrophilic sweat storage layer and a hydrophobic sweat blocking layer are prepared at one time on the surface of the sweat-transmitting sensor electrode film by electrospinning to form a detection unit; Multiple detection units are stacked and combined, and the odd-numbered sweat sensing electrode films arranged in a selected direction are electrically connected to form a first electrode array composed of multiple first sweat sensing electrode layers, and the even-numbered sweat sensing electrode films are electrically connected to form a second electrode array composed of multiple second sweat sensing electrode layers.

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