Instant sweat detection device and preparation method thereof

Abstract

The invention relates to a sweat real-time detection device and a preparation method thereof, the sweat real-time detection device sequentially comprises a collection layer and a detection layer from bottom to top, the collection layer comprises a fitting area, a fan-shaped flow guide area and a collection area, the fitting area is used for fitting skin, and the flow guide area is used for guiding sweat into the collection area; a plurality of guide vanes facing the collecting area are arranged in the guide area, and the guide vanes are triangular; the collecting area is connected into the fan-shaped included angle of the flow guide area and penetrates through the collecting layer; the detection layer is internally provided with a drainage area, a detection area and a micro-channel, the drainage area corresponds to the collection area and is used for draining sweat in the collection area to the detection area, and the detection area is provided with a sweat detection chip; the micro-channel is emitted from the drainage area, penetrates through the detection area and extends to the outermost side of the detection layer. The sweat collection device has the characteristics of high sweat collection efficiency, sufficient sweat collection amount, timely sweat detection after collection, rapid sweat analysis and detection process, reliable detection result and the like.

Description

Technical Field

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

[0002] Sweat is a non-invasive biofluid, and the pH value of sweat can reflect the content of electrolyte concentration in sweat, thereby indicating human diseases and metabolic activities. In addition, biomarkers such as electrolytes, metabolites, and small molecule proteins in sweat can also be used to assess human health conditions, such as hydration status, cystic fibrosis, physical stress, and bone mineral loss. Due to its easy collection and rich information content, sweat has great potential in wearable sensing for non-invasive monitoring.

[0003] Traditional sweat sampling methods include whole body flushing sampling, patch sampling, polymer bag / membrane sampling, etc. These methods require professionals to complete tedious sampling operations, and the sampling process is long. Sweat is easy to evaporate during sampling, and biomarkers in sweat may degrade and affect the actual test results. Shortening the sweat sampling and filling time helps to conduct timely and comprehensive analysis and provide accurate information. Therefore, designing a portable, simple to operate, and short response time instant sweat detection device is an urgent problem to be solved.

[0004] Among the existing patent technologies, CN118021354A discloses a self-collection and self-filtration patch for physiological fluids on the body surface. The patent uses a primary liquid inlet and a secondary liquid inlet with a circular periphery to collect sweat. However, the sweat on the surface of the human body is usually secreted regionally over a large range. A single liquid inlet may not cover the sweat glands under the skin, making it difficult to collect enough sweat. A large-scale fitting area may also cause regional compression of the skin, resulting in obstruction of sweat secretion in the patch. Moreover, the patch can only be used to initially collect a small amount of sweat. The detection of sweat still requires the aid of additional detection equipment, which is inconvenient and inconvenient for real-time detection by users. CN117159041A discloses a bionic sweat collection microfluidic patch. The patent uses a strip-shaped sweat collection channel at the bottom of the patch for collection. After collection, the sweat is sucked by a push-type sweat suction pump above. After the reaction chamber switch is manually opened, a test strip is placed in the patch for detection. However, the strip-shaped sweat collection channel still faces problems such as small sweat collection area and affecting sweat secretion. In addition, the device needs to manually turn on the switch and insert the test paper to press and absorb sweat. The operation process is cumbersome, and if the patch is attached to the arm, the user can only operate it with one hand, which is also inconvenient.

[0005] Therefore, an ideal sweat sensor should be easy to operate, able to collect sweat efficiently and in sufficient quantities, and quickly transport the collected samples from the collection area to the sensing area, quickly obtain sweat analysis results in the sensing area, and provide users with instant test results, so that users can understand real and accurate information. Summary of the invention

[0006] To achieve the above objectives, the present application provides an instant sweat detection device that can efficiently and sufficiently collect sweat and promptly and rapidly analyze and detect sweat.

[0007] The instant sweat detection device provided in the present application comprises, from bottom to top:

[0008] The collection layer comprises a fitting area, a fan-shaped guide area and a collection area, wherein the fitting area is used to fit the skin, and the guide area is used to guide the sweat to the collection area; the guide area is provided with a plurality of guide blades facing the collection area, and the guide blades are triangular; the collection area is connected to the fan-shaped angle of the guide area and runs through the collection layer;

[0009] The detection layer is provided with a drainage area, a detection area and a microchannel. The drainage area corresponds to the collection area and is used to drain the sweat in the collection area to the detection area. The detection area is provided with a sweat detection chip. The microchannel emanates from the drainage area, passes through the detection area and extends to the outermost side of the detection layer.

[0010] More specifically, the detection layer includes at least two detection areas, each detection area is connected to a different microchannel, and different microchannels guide sweat to different detection areas.

[0011] More specifically, the guide vane is a curved triangular blade with a transverse curvature and a longitudinal curvature, the transverse curvature radius R1 is 300-600 μm, and the longitudinal curvature radius R2 is 500-800 μm.

[0012] More specifically, the guide vane has a height of 400-800 μm, a bottom width of 400-800 μm, a radial spacing of 550-750 μm, an arc spacing of 200-600 μm, and an inclination angle of 40-80° between adjacent guide vanes.

[0013] More specifically, the height of the collection layer is 600-1000 μm, the height of the flow guide area is 400-800 μm, the height of the detection layer is 400-600 μm, and the height of the microchannel is 300-500 μm.

[0014] The preferred dimensional data of the device are: collection layer height 800μm, guide area height 600μm, guide blade height consistent with guide area height 600μm, blade bottom edge width 600μm, blade lateral curvature R1 400μm, longitudinal curvature R2 650μm, radial spacing between guide blades 400μm, arc spacing 550μm, and the inclination angle of the guide blade is 60°.

[0015] More specifically, the collection area, drainage area and detection area are all circular.

[0016] The present application also provides a method for preparing a sweat instant detection device, comprising the following steps:

[0017] S1. Prepare a collection layer mold and a detection layer mold;

[0018] S2, uniformly mixing the resin prepolymer and the curing agent and removing bubbles to obtain a mixture, placing the mixture into a collection layer mold and a detection layer mold respectively, and after the mixture is cured and demolded, obtaining a collection layer and a detection layer;

[0019] S3, performing surface plasma treatment on the collection layer and the detection layer and then performing surface hydrophilic modification treatment;

[0020] S4, placing the sweat detection chip into the detection area of ​​the detection layer after the surface hydrophilic modification treatment, aligning the collection layer and the detection layer and bonding them;

[0021] S5. After bonding, a bonding film is bonded to the bonding area of ​​the collection layer to obtain a sweat instant detection device.

[0022] More specifically, the ratio of the resin prepolymer to the curing agent is 15:1 to 10:1.

[0023] More specifically, the surface hydrophilic modification treatment in step S3 is as follows: immersing the collection layer and the detection layer in 8% (w / v) polyvinyl pyrrolidone solution for 3 minutes, washing with deionized water and vacuum drying.

[0024] The beneficial effects of the instant sweat detection device designed by the present invention are:

[0025] 1. The diversion area designed in the present invention is a fan-shaped contact port, which has a large sweat collection area and can cover more sweat glands. Even when the skin sweats slightly, it can collect enough sweat for analysis and detection, and the human body does not need to perform additional sweat-inducing exercises.

[0026] 2. The collection layer designed in this application has high sweat collection efficiency, and the guide blades in the guide area have a self-driven directional transportation function, and the sweat is collected in a centralized manner. During the collection process, there is no volatilization of sweat, and the analytical markers in the sweat are not decomposed. The material selection of the device does not pollute the sweat, the sweat quality is good, and the analysis and detection results are true and reliable.

[0027] 3. The instant sweat detection device designed in this application has good biocompatibility. The materials used in the device are green, safe and pollution-free. The structure is plasma treated both inside and outside, does not harm the skin, and does not cause discomfort when attached to the skin. There are no strict requirements on the attachment area, and the device can be attached to the arms, thighs, forehead, neck and other areas.

[0028] 4. The instant sweat detection device designed by the present invention integrates sweat collection and sweat detection. The detection layer is directly connected to the collection layer, and a sweat detection chip is built in. The user does not need to perform additional operations. The device can automatically complete the collection and detection work by simply sticking the device on the skin. The device has high sweat collection efficiency, sufficient sweat collection volume, timely arrival of sweat at the detection area after collection, and rapid sweat analysis and detection process. The user can obtain and intuitively observe the color change of the sweat detection chip in the detection area without the help of complex analytical instruments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a disassembled schematic diagram of the instant sweat detection device in this application;

[0030] Figure 2 It is a schematic diagram of the detection layer of the three detection zones in this application;

[0031] Figure 3 It is a schematic diagram of the manufacture and assembly of the instant sweat detection device in this application;

[0032] Figure 4 It is a schematic diagram of the use of the instant sweat detection device in this application;

[0033] Figure 5 It is a schematic diagram of the linear relationship between sweat pH value and RRG value in this application.

[0034] In the figure: 1. Fitting area; 2. Guide area; 3. Collection area; 4. Drainage area; 5. Detection area; 6. Microfluidic channel. DETAILED DESCRIPTION

[0035] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] like Figure 1 As shown, the instant sweat detection device designed by the present invention includes a collection layer and a detection layer from bottom to top. The collection layer includes a fitting area 1, a fan-shaped guide area 2 and a collection area 3. The fitting area 1 has good skin adhesion and is in gentle contact with the skin when fitting the skin. The guide area 2 is used to guide the sweat to the collection area; the guide blade facing the collection area 3 is arranged in the guide area 2, and the guide blade is a triangular Araucaria leaf bionic ratchet structure. The self-driving effect of the Araucaria leaf bionic structure is used to guide the discrete sweat secreted by the skin in the fan-shaped area to the collection area 3. The collection area 3 is connected to the fan-shaped circular part of the guide area 2 and runs through the entire collection layer and is connected to the detection layer. The detection layer is provided with a drainage area 4, a detection area 5 and a microchannel 6, which is emitted from the drainage area 4 and runs through the detection area 5 and extends to the outermost side of the detection layer. In order to reduce the dead volume in the device, the collection area, the drainage area 4 and the detection area 5 are all set to be circular. The drainage area 4 is connected to the collection area 3. When the collection area 3 collects enough sweat, the capillary action of the microchannel 6 will drain the sweat from the drainage area 4 to the detection area 5. The detection area 5 is provided with a sweat detection chip, which can complete the real-time detection of sweat. At the same time, the detection layer is set as a transparent thin layer as a whole. The user can intuitively observe the color development status of the sweat detection chip in the detection area and obtain the sweat detection information in time.

[0039] The instant detection device designed in the present application is thin as a whole, with a thickness of less than 2 mm, wherein the height of the collection layer is 600-1000 μm, the height of the guide area 2 and the collection area 3 is 400-800 μm, the height of the detection layer is 400-600 μm, and the height of the drainage area 4, the detection area 5 and the microchannel 6 is 300-500 μm. The height of the guide vane in the guide area 2 is 400-800 μm, the bottom width is 400-800 μm, the radial spacing between the guide vanes is 550-750 μm, the arc spacing is 200-600 μm, and the inclination angle of the guide vane is 40-80°. In the fan-shaped guide area 2, the guide vanes are distributed in layers in the shape of annual rings, wherein the radial spacing refers to the spacing between the guide vanes of adjacent layers in the direction of the fan straight edge, and the arc spacing refers to the spacing between adjacent guide vanes in the same layer.

[0040] The preferred size data of the device are: the height of the collection layer is 800μm, the height of the guide area 2 is 600μm, the height of the guide blade is consistent with the height of the guide area 2, which is 600μm, the width is 600μm, the transverse curvature R1 of the blade is 400μm, the longitudinal curvature R2 is 650μm, the arc spacing between the guide blades is 400μm, the radial spacing is 550μm, and the inclination angle of the guide blade is 60°. The sweat collection rate of the instant sweat detection device designed in this application is fast. Although the sweat collection rate is related to many objective factors such as the exercise mode, physical condition, and ambient temperature of the test subject, after actual testing of several volunteers, the sweat collection rate can reach 25-40μL / min, and the device can complete the detection within 7-15 minutes. The guide blade designed in this application has a good diversion effect and a strong self-driving force. After the sweat is secreted, it can be quickly diverted to the collection area 3. When the blade arc spacing is 400μm, the radial spacing is 550μm, the blade height is 600μm, the lateral curvature is 400μm, and the longitudinal curvature is 650μm, the liquid flow rate in the microchannel 6 is the fastest. The liquid pumping speed of 180μl / min is used to simulate the sweat secretion process of the skin, and the liquid flow rate in the microchannel 6 is measured to reach 275μm / s.

[0041] In some specific embodiments, the skin-conforming film can be directly set on the fitting area 1 of the collection layer, or a thin fitting layer of a corresponding shape can be additionally set on the fitting area 1, and then the fitting film can be pasted on the fitting layer. The fitting film can be a commercially available fitting film IV3000 or other medical sterile patch.

[0042] In some specific embodiments, a plurality of detection areas 5 and corresponding microchannels 6 are provided in the detection layer. The microchannels 6 can drain sweat from the drainage area 4 to different detection areas 5. Sweat detection chips for different detection items are placed in different detection areas 5. Users can obtain the detection results of multiple sweat markers at the same time. Figure 2In one embodiment shown, three detection areas 5 are provided in the detection layer, including a first detection area 5 where a sweat pH detection chip is placed, a second detection area 5 where a sweat glucose detection chip is placed, and a third detection area 5 where a sweat chloride detection chip is placed. According to the actual detection project requirements, the detection areas 5 can also be set to two, four or other numbers.

[0043] The preparation method of the instant sweat detection device designed in this application specifically comprises the following steps:

[0044] S1. Use modeling software (such as 3DS Max, Solid Works) to build mold models in the collection layer and detection layer styles respectively, and use 3D printer P150 prints the mold. After printing, remove the mold print from the printing platform, soak it in isopropyl alcohol for 10 minutes, rinse it with deionized water, and then place it in a vacuum drying oven to dry the mold for 20 minutes. The dried mold is UV cured for 12 hours and placed in an oven at 120 degrees Celsius for 3 hours. Finally, the collection layer mold and the detection layer mold are obtained.

[0045] S2, adoption 184 material, the resin polymer (Aldrich 761036A) and the curing agent (Aldrich 761036B) were uniformly mixed at a weight ratio of 10:1, and then uniformly filled into the collection layer mold, and then placed in a vacuum dryer for degassing for 1 hour to remove bubbles, and cured at 60°C for 180 minutes, and the polydimethylsiloxane (PDMS) collection layer was obtained after demolding. The detection layer was prepared in the same way.

[0046] S3. The prepared collection layer and detection layer are thoroughly washed with ethanol and deionized water. After drying, they are treated with high-power air plasma for 3 minutes to activate their surfaces. The collection layer and detection layer are then immersed in 8% (w / v) polyvinyl pyrrolidone solution for 3 minutes. After washing with deionized water, they are vacuum dried to obtain collection layers and detection layers with long-term hydrophilic surfaces.

[0047] S4. Spin-coat a mixture of resin polymer (Aldrich 761036A) and curing agent (Aldrich 761036B) in a ratio of 20:1 into a culture dish at a speed of 3000 rpm to form a PDMS prepolymer thin layer. Place the PDMS prepolymer thin layer on the back of the collection layer (the other side relative to the guide area), place a sweat detection chip in the detection area of ​​the detection layer, align the side of the detection layer containing the detection area with the back of the collection layer, and let it stand at room temperature for 24 hours to obtain a collection layer and detection layer that are tightly bonded.

[0048] S5, after bonding, bonding a bonding film to the bonding area of ​​the collection layer to obtain a sweat instant detection device. The bonding film is a commercially available thin bonding film IV3000, and other similar films can also be used.

[0049] The sweat detection chip in the detection area can be composed of Whatman chromatographic filter paper with added mercuric thiocyanate reagent. Specifically: Cut the Whatman chromatographic filter paper into a circle with a diameter of 3 mm, add 0.4 μL of mercuric thiocyanate reagent to the circular filter paper to make a chloride detection area, and after volatilization, a light orange circular filter paper piece for detecting chloride in sweat is obtained. The sweat detection chip can also be a calcium ion test paper, a glucose test paper, a pH test paper, etc.

[0050] like Figure 4 As shown, the instant sweat detection device designed in the present application only needs to stick the collection layer to the skin when in use. After the skin secretes sweat, the guide blades in the guide area can quickly guide the sweat into the collection area. The sweat in the collection area flows from the drainage area through the microchannel into the detection area with the help of capillary action, and the instant detection of sweat is completed in the detection area.

[0051] pH measurement is crucial in sweat monitoring because it can reflect changes in the concentration of various electrolytes in sweat, which can indicate disease and metabolic activity. For example, the pH of healthy people is in the range of 4.5-6.5, but in patients with cystic fibrosis, pH is increased due to bicarbonate reabsorption. + The pH value of sweat is also an indicator of the intensity of human exercise and the degree of dehydration. During exercise, the concentration of ammonia in sweat increases due to conversion to NH 4+ Compared with ammonia, NH 4+ The diffusion capacity of NH4+ in the cell membrane is poor, so the excess NH4+ 4+ The pH value of sweat can be detected quickly and accurately by using the instant sweat detection device designed in the present application.

[0052] The present application also provides a method for making a pH sweat detection chip: use a laser cutter to cut Whatman filter paper into circles with a diameter of 3 mm, add 0.5 μL of a universal indicator onto the circular filter paper to make a pH detection area, and after volatilization, obtain a light orange circular filter paper for detecting pH. The prepared pH sweat detection chip is assembled in the instant sweat detection device designed in the present application. When in use, the device is attached to the arm, and the sweat secreted by the skin quickly flows into the detection chamber. The color change of the detection chip is observed to obtain the pH value of the sweat. An electronic device can also be used to take a picture of the pH sweat detection chip, and the RGB value in the area is read to obtain the detection result. The linear relationship between the pH value and the RGB value is as shown in Figure 5 shown.

[0053] The sweat calcium ion detection chip can be prepared based on the calcium test kit of Nanjing Jiancheng Bioengineering Institute (methyl thymol blue colorimetric method), 2 μL alkaline solution (pH = 11) and 1 μL methyl thymol blue solution are added to the circular filter paper in sequence, and the detection reagent is fixed after drying to obtain the calcium ion detection chip. The final detection result adopts a strategy similar to pH, using electronic equipment to collect RGB information in the calcium ion detection chip, and the calcium ion concentration data in sweat is obtained according to the comparison table. The sweat glucose detection chip can be based on the glucose oxidase (GOx) and potassium iodide (KI) reaction system, 2.0 μL KI (0.6M) and 2.0 μL GOx (15U / mL) are dispersed in the circular filter paper, and the detection reagent is fixed after complete drying to obtain the glucose detection chip. The final detection result adopts a strategy similar to pH, using electronic equipment to collect RGB information in the glucose detection chip, and the glucose content data in sweat is obtained according to the comparison table.

[0054] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the protection scope of the present invention.

Claims

1. A sweat instant detection device, characterized in that: From bottom to top, they include: The collection layer includes a fitting area, a fan-shaped guide area and a collection area, wherein the fitting area is used to fit the skin, and the guide area is used to guide the sweat to the collection area; the guide area is provided with a plurality of guide blades facing the collection area, and the guide blades are triangular; the collection area is connected to the fan-shaped center of the guide area and passes through the collection layer; The detection layer is provided with a drainage area, a detection area and a microchannel. The drainage area is connected with the collection area and is used to drain the sweat in the collection area to the detection layer. The detection area is provided with a sweat detection chip. The microchannel emanates from the drainage area, passes through the detection area and extends to the outermost side of the detection layer.

2. The instant sweat detection device according to claim 1, characterized in that: The detection layer includes at least two detection areas, each detection area is connected to a different microchannel, and different microchannels drain sweat from the drainage area to different detection areas.

3. The instant sweat detection device according to claim 1, characterized in that: The guide vane is a curved triangular vane with a transverse curvature and a longitudinal curvature, the transverse curvature radius R1 is 300-600 μm, and the longitudinal curvature radius R2 is 500-800 μm.

4. The instant sweat detection device according to claim 1, characterized in that: The guide vanes have a height of 400-800 μm, a bottom width of 400-800 μm, a radial spacing of 550-750 μm and an arc spacing of 200-600 μm between adjacent guide vanes, and an inclination angle of 40-80°.

5. The instant sweat detection device according to claim 1, characterized in that: The height of the collection layer is 600-1000 μm, and the height of the guide area is 400-800 μm.

6. The instant sweat detection device according to claim 1, characterized in that: The height of the detection layer is 400-600 μm, and the height of the microchannel is 300-500 μm.

7. The instant sweat detection device according to claim 1, characterized in that: The collection area, drainage area and detection area are all circular.

8. A method for preparing a sweat instant detection device, characterized in that: The following steps are involved: S1. Prepare a collection layer mold and a detection layer mold in the style of the instant sweat detection device according to any one of claims 1 to 7; S2, uniformly mixing the resin prepolymer and the curing agent and removing bubbles to obtain a mixture, placing the mixture into a collection layer mold and a detection layer mold respectively, and after the mixture is cured and demolded, obtaining a collection layer and a detection layer; S3, performing surface plasma treatment on the collection layer and the detection layer and then performing surface hydrophilic modification treatment; S4, placing the sweat detection chip into the detection area of ​​the detection layer after the surface hydrophilic modification treatment, aligning the collection layer and the detection layer and bonding them; S5. After bonding, a bonding film is bonded to the bonding area of ​​the collection layer to obtain a sweat instant detection device.

9. The preparation method according to claim 8, characterized in that: The ratio of the resin prepolymer to the curing agent is 15:1 to 10:

1.

10. The preparation method according to claim 8, characterized in that: The surface hydrophilic modification treatment in step S3 is specifically as follows: immersing the collection layer and the detection layer in a polyvinyl pyrrolidone solution for 3 minutes, then washing with deionized water and vacuum drying.

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