Sweat detection sensor patch based on microfluidic technology

Abstract

The invention belongs to the field of flexible electronic devices, and particularly relates to a sweat detection sensor patch based on a microfluidic technology. Comprising a flexible micro-fluidic channel patch and a sensing electrode patch, the front surfaces of the flexible micro-fluidic channel patch and the sensing electrode patch are mutually bonded, the front surface of the flexible micro-fluidic channel patch is provided with a sweat collecting groove, a perspiration groove and a plurality of vertically-through sweat inlet holes, the sweat inlet holes are communicated with the sweat collecting groove through a Tesla valve flow channel, the perspiration groove is communicated with the sweat collecting groove through a perspiration flow channel, and the perspiration flow channel is communicated with the sensing electrode patch. The sensing electrode patch comprises a detection part and a pin part, a plurality of working electrodes and a reference electrode are arranged at the position, corresponding to the sweat collecting groove, of the front face of the detection part, a plurality of pins are arranged on the front face of the pin part side by side, and the working electrodes and the reference electrode are connected with the pins in a one-to-one correspondence mode through wires; and perspiration holes are formed in positions, corresponding to the perspiration grooves, on the detection part. According to the invention, the sweat can be continuously, accurately, comprehensively and efficiently detected, so that the health condition of a human body can be accurately and comprehensively monitored.

Description

Technical Field

[0001] The invention belongs to the field of flexible electronic devices, and in particular relates to a sweat detection sensor patch based on microfluidic technology. Background Art

[0002] As people pay more attention to health monitoring, the use of wearable devices for physiological data monitoring has become a hot research field. In the current field of health monitoring technology, wearable devices have become an important tool for health data monitoring due to their portability, real-time and efficiency. Traditional health monitoring methods usually rely on professional equipment in hospitals and medical institutions. Although these devices are highly accurate, they are complicated to operate, expensive and inconvenient for daily use. The emergence of wearable devices has made personal health monitoring more convenient and popular. Specifically, wearable devices can measure pulse, respiratory rate, body temperature and other health status indicators.

[0003] Among the numerous wearable devices, sweat sensors are a type of wearable bioelectronic sensor that has attracted much attention because sweat contains a variety of key biomarkers, such as electrolytes, metabolites, amino acids, hormones, and drug levels. However, there are several key problems with current sweat sensors. First, existing sensors lack effective continuous monitoring methods. They usually rely only on ion selectivity and direct oxidation of enzyme electrodes or electroactive molecules, which can only measure a limited set of biomarkers, such as electrolytes, glucose, and lactate. In addition, existing sweat sensors often only detect one biomarker, which, when used alone, cannot provide sufficiently comprehensive health status information, making it difficult to serve as an effective preventive tool. At the same time, many existing devices fail to optimize sweat collection and transmission channels, resulting in slow sweat collection speed and affecting detection accuracy. In addition, existing devices are usually made of rigid materials, which are difficult to fit closely to the skin, affecting wearing comfort. In addition, sweat sensors face other challenges, including complex manufacturing processes, difficulty in economical mass production, and fragility of the device, which makes them unsuitable for long-term wearable use. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides a sweat detection sensor patch based on microfluidic technology, and specifically discloses the following technical solutions:

[0005] A sweat detection sensor patch based on microfluidic technology comprises a flexible microfluidic channel patch and a sensing electrode patch, wherein a sweat collecting groove is provided at the center of the front side of the flexible microfluidic channel patch, a plurality of sweat inlet holes which are connected up and down are arranged around the sweat collecting groove, each of the sweat inlet holes is connected to the sweat collecting groove through a Tesla valve flow channel arranged on the front side of the flexible microfluidic channel patch, a sweat drainage groove is provided on the front side of the flexible microfluidic channel patch which is located on one side of the sweat collecting groove, the sweat drainage groove is connected to the sweat collecting groove through the sweat drainage flow channel, and the sensing electrode patch comprises a detection part and an induction part. The foot portion, the shape of the detection portion is the same as that of the flexible microfluidic channel patch, the pin portion is connected to one side of the detection portion, and a plurality of working electrodes and a reference electrode are arranged on the front side of the detection portion corresponding to the position of the sweat collecting groove, and a plurality of pins are arranged side by side on the front side of the pin portion, and a plurality of the working electrodes and a reference electrode are respectively connected to a plurality of the pins one by one through wires, and a sweat hole that passes through from top to bottom is opened on the position of the detection portion corresponding to the sweat collecting groove, and the front side of the flexible microfluidic channel patch is bonded to the front side of the detection portion of the sensing electrode patch.

[0006] Furthermore, the plurality of sweat inlet holes are circular through holes with the same inner diameter.

[0007] Furthermore, the sweat collecting groove is a circular groove, and the sweat collecting groove is used to collect and store sweat.

[0008] Furthermore, the direction with the smallest flow resistance in the Tesla valve flow channel is the direction from the sweat inlet hole to the sweat collecting groove.

[0009] Furthermore, the sweat groove and the sweat hole are both circular in shape, and the inner diameter of the sweat groove is the same as the inner diameter of the sweat hole.

[0010] Furthermore, the plurality of working electrodes are circular electrodes of the same size, and the reference electrode is an arc-shaped electrode.

[0011] Furthermore, each of the working electrodes is modified with carbon paste and sensing material.

[0012] Furthermore, the plurality of pins are arranged at equal intervals, and the plurality of pins have the same shape and size.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The present invention can continuously collect new sweat through the sweat inlet pores and the sweat outlet pores for detection, thereby being able to continuously monitor the health condition of the human body.

[0015] In the present invention, by modifying different sensing materials on the working electrode, a variety of different biomarkers in sweat can be detected, thereby reflecting the overall health status of the human body.

[0016] The central sweat inlet hole and the sweat collecting groove of the present invention are connected by a Tesla valve flow channel, which can realize efficient one-way collection of sweat, thereby improving the collection efficiency and ensuring the detection accuracy.

[0017] The invention is made of flexible material and can fit closely to the skin after being worn, so the wearing comfort is higher.

[0018] The invention has a simple structure, is easy to manufacture, and can realize large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the front structure of the flexible microfluidic channel patch.

[0020] Figure 2 Schematic diagram of the local structure of the Tesla valve flow channel.

[0021] Figure 3 Schematic diagram of the back structure of the flexible microfluidic channel patch.

[0022] Figure 4 This is a schematic diagram of the front structure of the full-page sensing electrode patch.

[0023] Figure 5 This is a schematic diagram of the front structure of a single sensing electrode patch.

[0024] Figure 6 A schematic diagram of the back structure of a single sensing electrode patch.

[0025] Figure 7 Schematic diagram of the bonding of the flexible microfluidic channel patch and the sensing electrode patch.

[0026] Figure 8 It is a schematic diagram of the overall structure of the present invention.

[0027] Fig. 9 These are the velocity simulation diagram and pressure simulation diagram in the Tesla valve flow channel.

[0028] Fig.10 Schematic diagram of the effect of different widths of Tesla valve flow channels and different flow rates on the pressure difference ratio Di when the arc angle is 45°.

[0029] 1-flexible microfluidic channel patch, 2-sensing electrode patch, 3-sweat collecting groove, 4-sweat inlet hole, 5-Tesla valve channel, 6-sweat trough, 7-working electrode, 8-reference electrode, 9-pin, 10-sweat pore. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0031] Reference Figure 1-10 A sweat detection sensor patch based on microfluidic technology includes a flexible microfluidic channel patch 1 and a sensing electrode patch 2. A sweat collecting groove 3 is provided at the center of the front of the flexible microfluidic channel patch 1. A plurality of sweat inlet holes 4 are provided around the sweat collecting groove 3. Each sweat inlet hole 4 is connected to the sweat collecting groove 3 through a Tesla valve flow channel 5 provided on the front of the flexible microfluidic channel patch 1. A sweat drainage groove 6 is provided on one side of the sweat collecting groove 3 on the front of the flexible microfluidic channel patch 1. The sweat drainage groove 6 is connected to the sweat collecting groove 3 through the sweat drainage flow channel. The sensing electrode patch 2 includes a detection part And a pin portion, the shape of the detection portion is the same as that of the flexible microfluidic channel patch 1, the pin portion is connected to one side of the detection portion, and a plurality of working electrodes 7 and a reference electrode 8 are arranged on the front side of the detection portion corresponding to the position of the sweat collecting groove 3, and a plurality of pins 9 are arranged side by side on the front side of the pin portion, and a plurality of working electrodes 7 and a reference electrode 8 are respectively connected to a plurality of pins 9 one by one through wires, and a sweat hole 10 that passes through from top to bottom is opened at the position corresponding to the sweat groove 6 on the detection portion, and the front side of the flexible microfluidic channel patch 1 is bonded and fitted with the front side of the detection portion of the sensing electrode patch 2.

[0032] In this embodiment, both sides of the flexible microfluidic channel patch 1 are coated with adhesive, the adhesive on the front side can be easily bonded to the sensor electrode patch 2, and the adhesive on the back side can be easily attached to human skin.

[0033] In this embodiment, the flexible microfluidic channel patch 1 is 26 mm long, 26 mm wide, and 0.6 mm thick. The flexible microfluidic channel patch 1 is obtained by printing a flexible material with a light-curing printer to ensure close fit with the skin and improve wearing comfort. In addition, the overall material is a hydrophilic material that can quickly transmit and mix sweat to ensure efficient collection and detection.

[0034] In this embodiment, the plurality of sweat inlet holes 4 are all circular through holes with the same inner diameter. The radius of the sweat inlet holes 4 is 1.5 mm and the depth is 0.6 mm.

[0035] In this embodiment, the width of the sweat channel is 0.4 mm and the depth is 0.4 mm.

[0036] In this embodiment, the sweat collecting groove 3 is a circular groove with a radius of 9 mm and a depth of 0.4 mm. The sweat collecting groove 3 is used to collect and store sweat.

[0037] In this embodiment, each Tesla valve flow channel 5 is composed of four arc flow channels, the flow channel width and height are both 0.4mm, the width of a single arc flow channel is 0.4mm, the corresponding arc angle is 45°, the length of the straight part is 1mm, the radius of the small arc is 0.414mm, and the radius of the large arc is 0.814mm. The direction with the smallest flow resistance in the Tesla valve flow channel 5 is the direction from the sweat inlet hole 4 to the sweat collecting groove 3, so as to collect sweat efficiently.

[0038] In this embodiment, the sweat groove 6 and the sweat hole 10 are both circular in shape, and the inner diameter of the sweat groove 6 is the same as the inner diameter of the sweat hole 10. The diameter of the sweat groove 6 is 1 mm and the depth is 0.4 mm. After the flexible microfluidic channel patch 1 and the sensor electrode patch 2 are bonded together, the sweat groove 6 should be aligned with the sweat hole 10 to ensure that the sweat collected by the flexible microfluidic channel patch 1 can be discharged smoothly.

[0039] In this embodiment, the sensing electrode patch 2 is designed through an FPC soft board and mass-produced in full version. Figure 4 As shown, one plate can print ten sensing electrode patches 2, and the left-right and top-bottom spacings between the sensing electrode patches 2 are both 2 mm. The overall length of the FPC soft board is 148 mm and the height is 136 mm.

[0040] In this embodiment, the plurality of working electrodes 7 are circular electrodes of the same size, the radius of the working electrode 7 is 1.5 mm, the reference electrode 8 is an arc-shaped electrode, the reference electrode 8 is arranged in a semi-enclosed shape at the periphery of the working electrode 7, the radius of the reference electrode 8 is 8 mm, the angle is 200°, and the width is 0.6 mm. The plurality of working electrodes 7 share one reference electrode 8, thereby forming four two-electrode electrochemical detection systems.

[0041] In this embodiment, each working electrode 7 is modified with carbon paste and sensing material. First, the carbon paste is modified on each working electrode 7 so that the carbon paste completely covers the surface of the working electrode 7, and electrochemical detection can be performed. Then, by continuing to modify different sensing materials on each working electrode 7, different biomarkers can be detected at the same time, so that the physiological parameters in the sweating process can be reflected to judge the sweating state, hydration status, and physiological activities such as aerobic and anaerobic exercise. For example, the first working electrode 7 is modified with a sodium ion selective membrane and open circuit potential (OCP) measurement is performed to detect the sodium ion concentration; the second working electrode 7 is modified with a potassium ion selective membrane and open circuit potential (OCP) measurement is also performed to detect the potassium ion concentration; the third working electrode 7 is modified with lactate oxidase and the chronoamperometry (CA) measurement is performed to detect the lactate concentration; the fourth working electrode 7 is modified with glucose oxidase and the chronoamperometry (CA) measurement is performed to detect the lactate concentration.

[0042] In this embodiment, the plurality of pins 9 are arranged at equal intervals, and the plurality of pins 9 have the same shape and size, the width of the pins 9 is 0.5 mm, the height is 3 mm, and the interval between the pins 9 is 1 mm.

[0043] As the subject sweats during exercise, the sweat will flow into the sweat inlet pore 4. The sweat flowing in through the sweat inlet pore 4 enters the circular sweat collecting groove through the corresponding Tesla valve flow channel 5 to participate in the electrochemical reaction of the working electrode 7 and the reference electrode 8. Due to the unidirectional flow-conducting characteristics of the Tesla valve flow channel 5, it is difficult for the sweat entering the sweat collecting groove 3 to flow back. The working electrode 7 and the reference electrode 8 can not only detect sodium ions and lactic acid, but can also be configured to detect various organic compounds in biological fluid samples. For example, they can detect metabolites, amino acids, vitamins, minerals, hormones, antibodies and other compounds. And it can also be configured as other types of sensors, such as enzyme sensors, tissue-based sensors, antibody sensors, DNA sensors or similar biosensors.

[0044] The sweat groove 6 of the flexible microfluidic channel patch 1 corresponds to the sweat hole 10 of the sensor electrode patch 2. When the space of the sweat collection groove 3 is completely filled with sweat, the sweat is allowed to flow out through the back of the sensor electrode patch 2, so that the sweat sample flowing out will not interfere with the incoming sweat sample. As the skin surface continues to sweat, new sweat will continue to flow into the sweat collection groove 3, so that the sensor patch can collect and sample the latest sweat samples over a long period of time, and the sweat samples are continuously analyzed by the working electrode 7 and the reference electrode 8.

[0045] In another embodiment, the user's stress can be analyzed and fatigue detection can be performed through the concentration of relevant metabolites.

[0046] In another embodiment, the sensor patch can be integrated into a smart watch, and the pin 9 of the sensor patch is connected to the smart watch through a magnetic interface. The smart watch is worn by the subject, so that the sensor patch collects sweat after contacting the subject's skin, and transmits the sweat data obtained after collection and analysis to the smart watch through the magnetic interface. The smart watch device can also analyze and display the health data collected from the sensor patch.

[0047] In another embodiment, a personalized nutrition plan can be developed by measuring the concentration of amino acids, vitamins, and minerals. After measuring these substances, the patient can be advised to make dietary adjustments, and the user can be helped to solve problems such as the deficiency or excess of amino acids, vitamins, and minerals.

[0048] In another embodiment, the sensor patch is capable of detecting drug compounds in sweat samples. The measurement of drug compounds can be used to assess patient compliance with medications, as well as the effectiveness of drug metabolism. By measuring drug compounds, the risk or severity of drug toxicity caused by a drug treatment regimen can also be determined.

[0049] In another embodiment, the sensor patch can also measure the concentration of antibodies in human sweat to help users indicate infection, the degree of immune response to viruses or bacteria, and other health conditions such as autoimmune diseases.

[0050] In another embodiment, the sensor patch can monitor hormone concentrations in sweat to help assess endocrine function, detect hormone imbalances in a timely manner, and help users monitor them.

[0051] For sweat collection, the Tesla valve flow channel is used in the flexible microfluidic channel patch 1 to achieve unidirectional conduction and collection of sweat. Fig. 9 Shown is a simulation diagram of velocity and pressure of the Tesla valve flow channel in the flexible microfluidic channel patch 1 at a flow rate of 0.5 m / s. Fig. 9 (a) shows the velocity simulation diagram of the Tesla valve flow channel when sweat flows in the forward direction. Fig. 9 (b) shows the velocity simulation diagram of the Tesla valve flow channel when sweat flows in the reverse direction. It can be seen that the Tesla valve flow channel shows obvious differences in liquid flow in different directions. When the liquid flows in the forward direction, there is almost no blockage in the channel, and most of the liquid passes directly through the straight flow channel and rarely through the arc flow channel. When the liquid flows in the reverse direction, the Tesla valve flow channel divides the liquid into two parts, one part flows through the straight flow channel and the other part flows through the arc flow channel. The velocity simulation intuitively shows the difference in liquid flow inside the Tesla valve flow channel under different flow directions.

[0052] Fig. 9(c) and 9(d) show the pressure simulation diagrams of the Tesla valve flow channel when sweat flows in the forward and reverse directions. Unlike the flow velocity simulation diagram, directly observing the pressure simulation diagram cannot obtain much useful information, so it is more intuitive to use the pressure difference ratio Di to measure the one-way flow guidance performance of the Tesla valve flow channel. When the liquid flows into the flow channel, whether the liquid flows in the forward or reverse direction, the pressure at the inlet must be greater than the pressure at the outlet. The pressure difference ΔP can be obtained by subtracting the pressure at the outlet from the pressure at the inlet. Due to the one-way flow guidance characteristics of the Tesla valve flow channel, the Tesla valve flow channel will hinder the reverse flow of the liquid. Therefore, theoretically speaking, the pressure difference ΔPR when the liquid flows in the reverse direction will be greater than the pressure difference ΔPF when the liquid flows in the forward direction. By calculating the ratio Di of ΔPR and ΔPF, the one-way flow guidance performance of the Tesla valve flow channel can be measured. The larger the Di value, the better the one-way flow guidance performance of the Tesla valve. When the Tesla valve has a flow channel width of 0.4 mm, an arc angle of 45°, and a flow rate of 0.5 m / s, the pressure difference ΔPF of the forward flow is approximately 627.92 Pa, while the pressure difference ΔPF of the reverse flow is approximately 2495.21 Pa, and the pressure difference ratio Di is approximately 3.97.

[0053] Fig.10 The figure shows the influence of different widths of the Tesla valve flow channel and different flow rates on the pressure difference ratio Di under the condition of a circular arc angle of 45°. The three curves represent the pressure difference ratios at different flow rates when the flow channel width is 0.2mm, 0.3mm and 0.4mm. It can be seen that at the same flow rate, the wider the flow channel width, the greater the pressure difference ratio Di; at the same flow channel width, the faster the flow rate, the greater the pressure difference ratio Di.

[0054] Therefore, when the channel width of the Tesla valve channel is 0.4 mm, the arc angle is 45°, and the flow rate is 0.5 m / s, the pressure difference ΔPF of the forward flow is approximately 627.92 Pa, and the pressure difference ΔPR of the reverse flow is approximately 2495.21 Pa. The pressure difference ratio Di can reach 3.97, which can achieve better unidirectional flow guidance and collection of sweat.

[0055] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A sweat detection sensor patch based on microfluidic technology, characterized in that: The invention comprises a flexible microfluidic channel patch and a sensor electrode patch, wherein a sweat collecting groove is provided at the center of the front side of the flexible microfluidic channel patch, a plurality of sweat inlet holes which are connected up and down are provided around the sweat collecting groove, each of the sweat inlet holes is connected to the sweat collecting groove through a Tesla valve flow channel provided on the front side of the flexible microfluidic channel patch, a sweat drainage groove is provided on the front side of the flexible microfluidic channel patch which is located on one side of the sweat collecting groove, the sweat drainage groove is connected to the sweat collecting groove through the sweat drainage flow channel, the sensor electrode patch comprises a detection part and a pin part, the shape of the detection part The shape is the same as that of the flexible microfluidic channel patch, the pin portion is connected to one side of the detection portion, and a plurality of working electrodes and a reference electrode are arranged on the front side of the detection portion corresponding to the position of the sweat collecting groove, and a plurality of pins are arranged side by side on the front side of the pin portion, and a plurality of the working electrodes and a reference electrode are respectively connected to a plurality of the pins one by one through wires, and a sweat hole that passes through from top to bottom is opened at the position corresponding to the sweat collecting groove on the detection portion, and the front side of the flexible microfluidic channel patch is bonded to the front side of the detection portion of the sensing electrode patch.

2. The sweat detection sensor patch based on microfluidic technology according to claim 1, characterized in that: The plurality of sweat inlet holes are all circular through holes with the same inner diameter.

3. The sweat detection sensor patch based on microfluidic technology according to claim 1, characterized in that: The sweat collecting groove is a circular groove, and the sweat collecting groove is used for collecting and storing sweat.

4. The sweat detection sensor patch based on microfluidic technology according to claim 1, characterized in that: The direction with the smallest flow resistance in the Tesla valve flow channel is the direction from the sweat inlet hole to the sweat collecting groove.

5. The sweat detection sensor patch based on microfluidic technology according to claim 1, characterized in that: The sweat drainage groove and the sweat drainage hole are both circular in shape, and the inner diameter of the sweat drainage groove is the same as the inner diameter of the sweat drainage hole.

6. The sweat detection sensor patch based on microfluidic technology according to claim 1, characterized in that: The plurality of working electrodes are circular electrodes of the same size, and the reference electrode is an arc-shaped electrode.

7. The sweat detection sensor patch based on microfluidic technology according to claim 1, characterized in that: Each of the working electrodes is modified with carbon paste and sensing material.

8. The sweat detection sensor patch based on microfluidic technology according to claim 1, characterized in that: The plurality of pins are arranged at equal intervals, and the plurality of pins have the same shape and size.

Images