Flexible wearable sweat sensor

Abstract

The utility model relates to a flexible wearable sweat sensor, which comprises a detection module, a hydrophobic film layer, a flow channel layer, an electrode layer, a skin glue layer and a release film layer which are regularly arranged from top to bottom, and the detection module is regularly and electrically connected with the electrode layer through a plug-in interface or an ejector pin type vibrating needle sequentially penetrating through the hydrophobic film layer and the flow channel layer. And the sensor is used for acquiring conductance signals in the plurality of detection interdigital electrodes on the electrode layer and converting the conductance signals into electrolyte concentration information and sweating amount information / sweating rate information. The sweat channel with a certain length is arranged, the sweat amount and the electrolyte concentration are detected in the sweat channel, the preparation process is simple, and one sensor patch can be manufactured only through simple attachment. The detection is based on the conductance principle, so that the sensor can realize real-time continuous detection on the sweating amount and the electrolyte concentration of the sweat through a conductance curve, and meanwhile, the sensor can be repeatedly used after the sweat is discharged out of the flow channel and is a non-disposable consumable.

Description

Technical Field

[0001] The utility model relates to the technical field of wearable devices and sensors, and in particular to a flexible and wearable sweat sensor. Background Art

[0002] Monitoring the human body's physical and chemical signals is crucial for preventing diseases, especially chronic diseases. However, efficient, continuous, real-time and non-invasive monitoring of the human body is still a challenge. The substances carried by sweat are closely related to the physiological state of the human body, so one of the important ways to achieve accurate and real-time detection and analysis of these biomarkers is to develop non-invasive, wearable sweat sensors.

[0003] As an important biological fluid for real-time health monitoring, sweat carries a large amount of substances that transmit human physiological information, such as metabolites (glucose, lactate), electrolytes (Na+, Cl-, K+), hormones (cortisol, dopamine (DA)), etc. The various physiological index parameters in sweat can effectively reflect the individual's physical health status. For example, sodium ion detection can timely warn of hyponatremia (serum sodium <135mmol / L); cortisol can reflect stress conditions, etc. Compared with other biological fluids of the human body (blood, tissue fluid, tears, urine, saliva, etc.), sweat is easy to obtain and non-invasively monitored. It plays an important physiological role in body temperature regulation, immune defense, electrolyte and pH balance, etc., and is confirmed as an important indicator for human health detection. In order to maintain the body's hydration balance during continuous sweating, it is necessary to customize a personalized rehydration strategy according to individual conditions. Sweating speed detection can provide a key basis for the formulation of rehydration strategies.

[0004] Wearable flexible sweat sensors can detect sweat rate and electrolyte concentration in real time and in situ, greatly facilitating people's lives. However, the current preparation methods of sweat sensors are relatively cumbersome and complicated, which undoubtedly increases the cost of sensors and reduces the target audience. Utility Model Content

[0005] The technical problem solved by the utility model is to provide a flexible and wearable sweat sensor which has a simple preparation process and is reusable.

[0006] The technical solution adopted by the utility model to solve its technical problems is:

[0007] A flexible wearable sweat sensor comprises a detection module, a hydrophobic film layer, a flow channel layer, an electrode layer, a skin adhesive layer and a release film layer which are regularly arranged from top to bottom;

[0008] The skin adhesive layer is arranged on the lower surface of the flexible substrate of the electrode layer, the skin adhesive layer is provided with regular openings, and a sweat receiving chamber is formed between the skin adhesive layer and the flexible substrate of the electrode layer, and the release film layer is attached to the lower surface of the skin adhesive layer to protect the skin adhesive layer;

[0009] The electrode layer includes the flexible substrate and a plurality of detection interdigital electrodes for testing which are regularly arranged on the upper surface of the flexible substrate, a liquid inlet is arranged on the flexible substrate, the plurality of interdigital electrodes are regularly arranged in front of the liquid inlet, and are regularly connected to a plurality of electrode contacts through leads arranged on the flexible substrate to form detection electrode contacts;

[0010] The flow channel layer is arranged on the upper surface of the electrode layer, and flow channels are regularly arranged on the flow channel layer. The flow channels are regularly arranged along the shapes of the plurality of detection interdigital electrodes and are arranged directly above the plurality of finger-shaped electrodes between the plurality of detection interdigital electrodes, so as to place the plurality of finger-shaped electrodes between the plurality of detection interdigital electrodes in the flow channel; the front end and the end of the flow channel are respectively provided with a flow channel inlet for the inflow of sweat and a flow channel outlet for the outflow of sweat, the flow channel inlet is communicated with the sweat containing chamber through the liquid inlet, and the flow channel outlet leads out of the flow channel layer and communicates with the outside;

[0011] The hydrophobic film layer is attached to the upper surface of the flow channel layer to seal and encapsulate the flow channel in the flow channel layer;

[0012] The detection module is attached to the upper surface of the hydrophobic film layer through a double-sided adhesive layer. The detection module is electrically connected to the electrode layer in a regular manner through the hydrophobic film layer and the flow channel layer in turn through a plug-in interface or a pin-type elastic needle to collect conductivity signals from the multiple detection interdigital electrodes on the electrode layer, and convert the conductivity signals into electrolyte concentration information and sweat amount information / sweating rate information.

[0013] Furthermore, the flow channel layer is a hydrophobic flow channel layer, and the bending parts of the hydrophobic flow channel layer are configured as rounded corners to form a hydrophobic flow channel.

[0014] Furthermore, the plurality of detection interdigital electrodes include a first interdigital electrode for electrolyte concentration testing and a second interdigital electrode for sweat amount / sweating rate testing, and the first interdigital electrodes and the second interdigital electrodes are regularly arranged in front of the liquid inlet; the second interdigital electrodes are S-shaped and cover the flexible substrate as much as possible, and the second interdigital electrodes are regularly arranged along the left and right sides of the liquid inlet.

[0015] Furthermore, the second interdigital electrodes on the left and right sides of the liquid inlet are arranged with equal distances and lengths on both sides of the liquid inlet to cover the left and right sides of the flexible substrate as much as possible.

[0016] Furthermore, electrode vias are regularly arranged on the flow channel layer and the hydrophobic membrane layer just above the plurality of electrode contacts to facilitate electrical connection between the detection module and the electrode layer.

[0017] Furthermore, electrode vias are regularly arranged on the double-sided adhesive layer just above the plurality of electrode contacts.

[0018] Furthermore, the sweat sensor patch is a flexible structure, and the detection module is a rigid structure.

[0019] Furthermore, the flexible substrate of the electrode layer is a thin film electrode, and the plurality of detection interdigital electrodes are conductivity electrodes.

[0020] The beneficial effects of the utility model are:

[0021] 1. The flexible wearable sweat sensor provided by the utility model sets a sweat channel of a certain length and detects the amount of sweat and electrolyte concentration in the sweat channel. The preparation process of the device is simple, and only simple bonding is required to complete the production of a sensor patch.

[0022] 2. The flexible wearable sweat sensor provided by the utility model is based on the principle of conductivity. Therefore, the sensor can realize real-time and continuous detection of sweat volume and sweat electrolyte concentration through the conductivity curve. At the same time, the sensor can be reused after the sweat is discharged from the flow channel, and it is not a disposable consumable.

[0023] 3. The utility model designs dual channels to detect the electrolyte concentration and sweat volume in sweat respectively. One sensor can detect two variables at the same time, realizing dual channels of detection, thereby making the detection results more accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is the structural explosion diagram of the utility model;

[0025] Figure 2 for Figure 1 Structural diagram of the middle electrode layer;

[0026] Figure 3 for Figure 1 Structural diagram of the mid-flow layer;

[0027] Figure 4 This is a schematic diagram of an electrical connection method between the detection module and the sweat sensor patch of the utility model;

[0028] Figure 5 It is a schematic diagram of another electrical connection method between the detection module and the sweat sensor patch of the utility model;

[0029] Figure 6 The relationship between the change of conductivity over time at different sweat flow rates at an electrolyte concentration of 100 mM in Example 1;

[0030] Figure 7 The relationship between the change of conductivity over time at different sweat flow rates at an electrolyte concentration of 100 mM in Example 2;

[0031] Figure 8 The relationship between the change of conductivity over time at different sweat flow rates at an electrolyte concentration of 100 mM in Example 3;

[0032] Fig. 9 This is a schematic diagram of the sweat sensor device of the utility model being attached to the surface of human skin;

[0033] in:

[0034] 1. Detection module, 2. Hydrophobic film layer, 3. Flow channel layer, 4. Electrode layer, 5. Skin adhesive layer, 6. Release film layer, 11. Double-sided adhesive layer;

[0035] 101. Elastic needle;

[0036] 301, flow channel, 302, flow channel inlet, 303, flow channel outlet, 3011, fillet, 304, electrode via;

[0037] 401, flexible substrate, 4011, liquid inlet, 402, detection interdigital electrode, 4021, first interdigital electrode, 4022, second interdigital electrode, 403, electrode contact;

[0038] 501, sweat storage chamber;

[0039] 701, male end, 702, female end. DETAILED DESCRIPTION

[0040] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0042] like Figure 1-5 As shown, the utility model provides a flexible wearable sweat sensor, including a detection module 1 and a sweat sensor patch. The sweat sensor patch is a flexible structure, the detection module 1 is a rigid structure, and the detection module is electrically connected to the sweat sensor patch through a plug-in terminal or a spring pin. The detection module is used to collect the conductivity signal in the sweat sensor patch and convert it into electrolyte concentration information and sweat amount information or sweat rate information.

[0043] The detection module integrates a DAC reference voltage generation unit, a voltage conversion unit, an AFE small signal acquisition unit and a wireless communication unit. The sweat sensor device of the utility model transmits signals wirelessly through the wireless communication unit, communicates with the circuit processing module through the wireless communication module, transmits the electrical output signal to the circuit processing module, and the signal processing circuit in the circuit processing module shapes, amplifies, filters, and performs A / D conversion on the received electrical output signal (analog signal) to obtain the output electrical signal (digital signal) of the sensor, and then converts the output electrical signal into a digital sweat monitoring parameter through the algorithm integrated in the circuit processing module.

[0044] like Figure 1 As shown, the detection module 1 is adhered to the upper surface of the sweat sensor patch through a double-sided adhesive layer 11.

[0045] Furthermore, the size of the detection module is less than or equal to the overall size of the sweat sensor patch.

[0046] like Figure 1 As shown, the sweat sensor patch includes a hydrophobic membrane layer 2, a flow channel layer 3, an electrode layer 4 and a skin glue layer 5 which are regularly arranged from top to bottom.

[0047] The skin adhesive layer 5 is used to adhere to human skin. The skin adhesive layer 5 is provided with regular openings, and a sweat receiving chamber 501 is formed between the skin adhesive layer 5 and the electrode layer substrate.

[0048] Furthermore, a release film layer 6 for protection is attached to the lower surface of the skin adhesive layer 5 .

[0049] When in use, tear off the release film layer 6, and attach the skin adhesive layer 5 to the human skin surface, so that the sweat sensor device of the utility model is attached to the human skin surface. When exercising, the human skin surface will continuously produce sweat, and the sweat on the human skin surface enters the sweat receiving chamber 501 between the skin adhesive layer 5 and the electrode layer base.

[0050] Preferably, the skin adhesive layer 5 is a hypoallergenic skin adhesive film to avoid or reduce allergic reactions to human skin as much as possible.

[0051] like Figure 2 , which is a structural diagram of the electrode layer 4. The electrode layer 4 includes a flexible substrate 401 and a plurality of detection interdigital electrodes 402 disposed on the upper surface of the flexible substrate. A liquid inlet 4011 is disposed on the flexible substrate 401. The liquid inlet is preferably disposed in the middle of the substrate and is connected to the sweat receiving chamber 501. The plurality of detection interdigital electrodes are regularly disposed in front of the liquid inlet 4011.

[0052] Further, the plurality of detection interdigital electrodes 402 include a first interdigital electrode 4021 for electrolyte concentration testing / detection and a second interdigital electrode 4022 for sweating amount or sweating rate testing / detection. The second interdigital electrode is S-shaped or serpentine-shaped and is regularly arranged in front of the first interdigital electrode.

[0053] Furthermore, the second interdigital electrodes 4022 of S-shaped design cover the upper surface of the flexible substrate 401 as much as possible, thereby utilizing the upper surface area of ​​the flexible substrate 401 as much as possible. Figure 2 As shown, in one embodiment, the second interdigital electrodes of S-shaped design are regularly arranged along the left and right sides of the liquid inlet 4011, and the finger electrodes of the second interdigital electrodes on the left and right sides are arranged equidistantly and of equal length on the left and right sides of the liquid inlet. Therefore, on a flexible substrate of the same area, a longer second interdigital electrode and flow channel can be arranged. In other words, with the second interdigital electrodes and flow channels of the same length, the sweat sensor patch of the utility model can be made smaller.

[0054] Furthermore, a plurality of electrode contacts 403 are regularly arranged on the flexible substrate 401, and a plurality of detection interdigital electrodes 402 are regularly electrically connected to corresponding electrode contacts 403 through leads. In one embodiment, six electrode contacts are arranged, and the first interdigital electrode and the second interdigital electrode are respectively connected to four of the electrode contacts through leads to form detection electrode contacts. The other two electrode contacts are used as power supply electrode contacts.

[0055] Furthermore, the flexible substrate uses a thin film electrode, and the thin film material can be polyimide, polydimethylsiloxane or polyethylene terephthalate. The detection interdigital electrode is a conductivity electrode, and the conductivity electrode material can be carbon nanotubes, graphene, carbon black or carbon fiber.

[0056] like Figure 3 , which is a structural diagram of the flow channel layer 3. The flow channel 301 is regularly arranged on the flow channel layer 3, and the front end and the end of the flow channel 301 are respectively provided with a flow channel inlet 302 for sweat to flow in and a flow channel outlet 303 for sweat to flow out. Among them, the flow channel inlet 302 is arranged just above the liquid inlet 4011 and is connected thereto, and the flow channel outlet 303 leads out of the flow channel layer 3 and is arranged on the side of the flow channel layer 3, so as to lead the flow channel out of the flow channel layer.

[0057] Furthermore, the flow channel inlet 302 on the flow channel layer 3, the liquid inlet 4011 on the electrode layer 4 and the sweat receiving chamber 501 on the skin adhesive layer 5 are vertically arranged and interconnected, so that the sweat secreted by the human body is first stored in the sweat receiving chamber 501, and then flows into the flow channel 301 in the flow channel layer from the liquid inlet 4011 on the electrode layer.

[0058] Furthermore, the flow channel 301 is arranged along the shape of the second interdigital electrode 4022 and is arranged directly above it, so as to drain the sweat on the plurality of finger electrodes of the second interdigital electrode to generate corresponding conductivity signals and realize the measurement of the amount of sweat. Therefore, in one embodiment, the flow channel 301 is arranged along the S-shaped second interdigital electrode, and an S-shaped flow channel of equal length and distance is formed on both sides of the flow channel inlet.

[0059] Furthermore, the plurality of finger electrodes of the first interdigitated electrode and the second interdigitated electrode are all disposed in the flow channel 301 .

[0060] Furthermore, the flow channel 301 is designed to have a rounded corner 3011 at the bend, and the base of the entire flow channel layer is made of hydrophobic material, thereby forming a hydrophobic flow channel to reduce the flow resistance of sweat in the flow channel.

[0061] like Figure 1 As shown, the hydrophobic membrane layer 2 covers the upper surface of the flow channel layer 3 , thereby covering and sealing the flow channels in the flow channel layer 3 , ensuring that sweat liquid can flow along the flow channels in the flow channel layer 3 .

[0062] Furthermore, the hydrophobic film layer is mainly cut into the main body shape by laser, and six through holes are cut on the surface by laser to facilitate the connection of the electrode with the outside world. The diameter of the through hole is 1.4 mm, and the distance between the six through holes is consistent with that on the electrode layer. The material of the hydrophobic film can be selected from polyethylene terephthalate (PET), ethylene-vinyl acetate copolymer (EVA) and other materials.

[0063] like Figure 4 and Figure 5 As shown, the utility model provides two ways of electrically connecting the detection module to the electrode contacts on the surface of the electrode layer:

[0064] The first way, such as Figure 4 As shown, a plug-in terminal is used to realize the electrical connection between the detection module and the electrode layer. Several electrode contacts 403 on the electrode layer 4 are led out through wires, and the wires are regularly gathered through the terminal to form a plug terminal (male end 701). Correspondingly, a plug-in interface (female end 702) extending out is provided on the detection module. The plug terminal led out of the electrode layer is inserted into the plug-in interface led out of the detection module, thereby realizing the electrical connection between the detection module and the electrode layer, that is, the electrical connection between the detection module and the sweat sensor patch. The detection module is pasted to a specified position on the upper surface of the sweat sensor patch through a double-sided adhesive layer 11.

[0065] Of course, the male end and the female end may also be arranged in reverse.

[0066] Furthermore, the plug-in interface may also be integrated on the detection module and arranged on the side or top of the detection module.

[0067] Furthermore, the wires leading out of the electrode layer pass through the flow channel layer and the hydrophobic film layer respectively. Therefore, electrode vias 304 are regularly arranged on the flow channel layer and the hydrophobic film layer just above the plurality of electrode contacts.

[0068] The second method, such as Figure 5 As shown, a pin-type elastic pin interface is used to realize the electrical connection between the detection module and the electrode contacts on the surface of the electrode layer. An equal number of elastic pins 101 for electrical connection are regularly arranged along a plurality of electrode contacts on the detection module 1 and extend out of the lower surface of the detection module. Electrode vias 304 are regularly arranged along a plurality of electrode contacts on the hydrophobic membrane layer 2 and the flow channel layer 3. A plurality of elastic pins 101 pass through the electrode vias on the hydrophobic membrane layer and the flow channel layer to be electrically connected to a plurality of electrode contacts on the surface of the electrode layer.

[0069] Furthermore, the detection module 1 is bonded and fixed to the upper surface of the hydrophobic film layer 2 through the double-sided adhesive layer 11 .

[0070] In order to improve the reliability of the detection module and the sweat sensor patch, the double-sided adhesive layer covers the lower surface of the detection module as much as possible. Therefore, in one embodiment, the double-sided adhesive layer 11 is also regularly provided with electrode vias for the spring needle to pass through.

[0071] The electrode vias 304 may be through holes having the same number as the electrode contacts 403 , or strip holes avoiding the electrode contact area.

[0072] Furthermore, in one embodiment, the overall length and width of the sweat sensor patch (including the skin glue layer, the electrode layer, the flow channel layer and the hydrophobic film layer) are greater than or equal to 6cm×3cm, the size of the detection module is less than or equal to the overall size of the sweat sensor patch, the sweat sensor patch is a flexible structure, and the detection module is a rigid structure. The diameter of the sweat storage chamber is 6-10mm, and the height is 100-200μm. The sweat storage chamber is a chamber formed by a layer of low-sensitivity skin glue vias and the electrode skin glue layer. The diameter of the sweat inlet on the electrode layer is 0.3mm~10mm, and the diameter of the sweat inlet on the surface of the flow channel layer is equivalent to that of the electrode layer, between 0.3mm~10mm. The entire sweat flow channel is designed to be rounded at the bend, and the inner wall is a hydrophobic flow channel with a width of 0.5~4mm and a thickness of 0.1~0.6mm. Among them, when the width is 1-2mm and the thickness is 0.15-0.3mm, it can better ensure the circulation of sweat, and at the same time, a sweat patch can meet the filling time of one hour, which is in line with the detection mode of outdoor sports. The flow channel also includes a sweat outlet, which is located at the exit of the sweat circulation channel, that is, the edge of the sweat sensor patch is drained.

[0073] Embodiment 1:

[0074] like Figure 1 and Figure 5 As shown, the present embodiment provides a wearable sweat sensor device for real-time and continuous detection of electrolyte concentration, comprising: a skin adhesive layer and an electrode layer, a silicone rubber flow channel layer, a hydrophobic membrane layer and a detection module sequentially arranged on the base skin adhesive layer.

[0075] A first sweat inlet is provided on the skin adhesive layer 5, and one end of the opening is provided close to the skin surface, so as to allow the sweat generated on the skin surface to be continuously input. A second sweat inlet is provided on the surface of the electrode layer 4, and the first sweat inlet and the second sweat inlet allow the sweat to enter the flow channel layer 3 after reaching the surface of the electrode layer.

[0076] The skin adhesive layer connects the skin and the electrode layer, and the skin adhesive layer provides a sweat receiving chamber 501. The electrode layer is used to detect the amount of sweat flowing through the sweat channel and / or detect the electrolyte concentration by analyzing electrical signals.

[0077] The skin adhesive layer is configured as a hypoallergenic skin adhesive film and a release film 6. When in use, the release film needs to be removed first and then attached to the skin surface.

[0078] The material used for the flow channel layer 3 is silicone rubber, and a sweat flow channel is arranged on its surface. The third sweat inlet of the sweat flow channel is vertically connected with the first sweat inlet and the second sweat inlet. The surfaces of the electrolyte concentration detection interdigital electrodes and the sweat amount detection interdigital electrodes of the electrode layer are located on the bottom surface of the sweat flow channel layer, and are used to detect the sweat flowing through the sweat channel to obtain the electrolyte concentration and sweat amount information in the sweat.

[0079] The flow channel layer is provided with a sweat outlet for conducting the input sweat out of the flow channel layer.

[0080] A hydrophobic film layer is arranged above the flow channel layer to seal the liquid in the flow channel to prevent overflow during use.

[0081] The skin glue layer, electrode layer, flow channel layer and hydrophobic film layer are called sweat sensor patch. The overall length and width of the sweat sensor patch are greater than or equal to 6cm*3cm, the size of the detection module is less than or equal to the overall size of the sweat sensor patch, the sweat sensor patch is a flexible structure, and the detection module is a rigid structure. The diameter of the sweat storage chamber is 6-10mm and the height is 100-200μm. The sweat storage chamber is a chamber formed by a layer of low-sensitivity skin glue vias and the electrode skin glue layer; the diameter of the sweat inlet on the electrode layer is 0.3mm~10mm. The diameter of the sweat inlet on the surface of the flow channel layer is equivalent to that of the electrode layer, between 0.3mm and 10mm. The entire sweat channel is designed with rounded corners at the bends, and the inner wall is a hydrophobic channel with a width of 0.5-4mm and a thickness of 0.1-0.6mm; when the width is 1-2mm and the thickness is 0.15-0.3mm, it can better ensure the circulation of sweat, and at the same time, a sweat patch can meet the one-hour filling time, which is in line with the detection mode of outdoor sports. The channel also includes a sweat outlet, which is located at the exit of the sweat circulation channel, that is, the edge of the sweat sensor patch is drained.

[0082] When used, the wearable sweat sensor device in this embodiment is attached to the skin surface, such as Fig. 9 As shown, when sweat is secreted from the sweat glands, it has a certain pressure, which can reach a maximum of 70000Nm-2, which is enough to pump the sweat into the first sweat inlet of the skin glue layer. When the sweat passes through the first sweat inlet and flows upward, it will successively contact the contact detection interdigital electrodes exposed on the surface of the electrode layer, and connect to the detection module through plug-in or pin-type to obtain the conductivity signal of the wearable sweat sensor device in real time. The continuous conductivity value of the sweat is recorded in real time by the conductivity detection instrument, and the conductivity curve is positively correlated with the real-time total concentration of sweat electrolytes and the amount of sweating. Among them, the time interval of the step signal change of the conductivity curve is directly proportional to the sweating speed, and the conductivity signal measured by the first interdigitated electrode is positively correlated with the real-time electrolyte concentration.

[0083] Therefore, a real-time and continuous conductivity curve can be used to obtain the real-time and continuous changes in sweat electrolyte concentration and sweat volume. When the flow channel layer is silicone rubber, some test results are as follows: Figure 6 As shown, the upper curve is 4 μl / min and the lower curve is 3 μl / min.

[0084] Embodiment 2:

[0085] The specific structure of this embodiment refers to that of Embodiment 1, wherein the material of the flow channel layer is a biaxially oriented polypropylene film.

[0086] When the flow channel layer is a biaxially oriented polypropylene film, some test results are shown in Figure 7, where the upper curve is 4 μl / min and the lower curve is 3 μl / min.

[0087] Embodiment 3:

[0088] The specific structure of this embodiment refers to that of Embodiment 1, wherein the material of the flow channel layer is polytetrafluoroethylene film.

[0089] When the flow channel layer is a biaxially oriented polypropylene film, some test results are shown in Figure 8, where the upper curve is 4 μl / min and the lower curve is 3 μl / min.

[0090] Figure 6-8 The horizontal axis is the time coordinate, and the vertical axis is the conductivity coordinate. Figure 6-8 The coordinates represent the relationship between conductivity and time at different sweat flow rates when the electrolyte concentration is 100 mM.

[0091] For different materials selected for the flow channel layer, the material inside the flow channel and the cutting accuracy on the inside bring different resistances to the liquid. The resistance of silicone material is relatively large, so the time of a single step signal is relatively long. Biaxially oriented polypropylene film is second, and the better one is polytetrafluoroethylene, which has high consistency of step signals.

[0092] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A flexible wearable sweat sensor, characterized in that: It includes a detection module, a hydrophobic film layer, a flow channel layer, an electrode layer, a skin glue layer and a release film layer which are regularly arranged from top to bottom; The skin adhesive layer is arranged on the lower surface of the flexible substrate of the electrode layer, the skin adhesive layer is provided with regular openings, and a sweat receiving chamber is formed between the skin adhesive layer and the flexible substrate of the electrode layer, and the release film layer is attached to the lower surface of the skin adhesive layer to protect the skin adhesive layer; The electrode layer includes the flexible substrate and a plurality of detection interdigital electrodes for testing which are regularly arranged on the upper surface of the flexible substrate, a liquid inlet is arranged on the flexible substrate, the plurality of interdigital electrodes are regularly arranged in front of the liquid inlet, and are regularly connected to a plurality of electrode contacts through leads arranged on the flexible substrate to form detection electrode contacts; The flow channel layer is arranged on the upper surface of the electrode layer, and flow channels are regularly arranged on the flow channel layer. The flow channels are regularly arranged along the shapes of the plurality of detection interdigital electrodes and are arranged directly above the plurality of finger-shaped electrodes between the plurality of detection interdigital electrodes, so as to place the plurality of finger-shaped electrodes between the plurality of detection interdigital electrodes in the flow channel; the front end and the end of the flow channel are respectively provided with a flow channel inlet for the inflow of sweat and a flow channel outlet for the outflow of sweat, the flow channel inlet is communicated with the sweat containing chamber through the liquid inlet, and the flow channel outlet leads out of the flow channel layer and communicates with the outside; The hydrophobic film layer is attached to the upper surface of the flow channel layer to seal and encapsulate the flow channel in the flow channel layer; The detection module is attached to the upper surface of the hydrophobic film layer through a double-sided adhesive layer. The detection module is electrically connected to the electrode layer in a regular manner through the hydrophobic film layer and the flow channel layer in turn through a plug-in interface or a pin-type elastic needle to collect conductivity signals from the multiple detection interdigital electrodes on the electrode layer, and convert the conductivity signals into electrolyte concentration information and sweat amount information / sweating rate information.

2. A flexible wearable sweat sensor as claimed in claim 1, characterized in that: The flow channel layer is a hydrophobic flow channel layer, and the bending part of the hydrophobic flow channel layer is configured as a rounded corner to form a hydrophobic flow channel.

3. A flexible wearable sweat sensor as claimed in claim 1, characterized in that: The plurality of detection interdigital electrodes include a first interdigital electrode for electrolyte concentration testing and a second interdigital electrode for sweat volume / sweat rate testing, and the first interdigital electrode and the second interdigital electrode are regularly arranged in front of the liquid inlet; The second interdigitated electrodes are designed in an S shape and cover the flexible substrate as much as possible. The second interdigitated electrodes are regularly arranged along the left and right sides of the liquid inlet.

4. A flexible wearable sweat sensor as claimed in claim 3, characterized in that: The second interdigital electrodes on the left and right sides of the liquid inlet are arranged with equal distances and lengths on both sides of the liquid inlet to cover the left and right sides of the flexible substrate as much as possible.

5. A flexible wearable sweat sensor according to any one of claims 1 to 4, characterized in that: Electrode vias are regularly arranged on the flow channel layer and the hydrophobic film layer just above the plurality of electrode contacts, which facilitate the electrical connection between the detection module and the electrode layer.

6. A flexible wearable sweat sensor as claimed in claim 5, characterized in that: Electrode vias are also regularly arranged on the double-sided adhesive layer just above the plurality of electrode contacts.

7. A flexible wearable sweat sensor as claimed in claim 1, characterized in that: The sweat sensor patch is a flexible structure, and the detection module is a rigid structure.

8. The flexible wearable sweat sensor according to claim 1, characterized in that: The flexible substrate of the electrode layer adopts a thin film electrode, and the plurality of detection interdigital electrodes are conductive electrodes.

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