Sweat wearable sensor and sweat detection method

Abstract

The invention discloses a wearable sweat sensor and a sweat detection method. The sweat wearable sensor comprises a sweat gathering layer, a channel layer, a sweat diversion layer, a detection layer and a sensor layer. The detection layer comprises a detection pool and a water storage pool; the detection pool is connected with the water storage pool through a capillary breakthrough valve; the capillary breakthrough valve enables the liquid to only enter the detection pool from the water storage pool in one direction; the sensor layer is provided with an external interface; and the external interface is connected with the reservoir.

Description

Technical Field

[0001] The present application relates to a wearable sweat sensor and a sweat detection method, and belongs to the field of wearable sensors. Background Art

[0002] Sweat contains electrolytes (K + 、Na + , Cl—, etc.), metabolites (glucose, uric acid, etc.) and nutrients (tyrosine, tryptophan, etc.). These substances can reflect the health of the human body. For example, the glucose concentration in sweat is positively correlated with the glucose concentration in blood. Sweat glucose is 1-2% of blood glucose concentration (European Journal of Clinical Nutrition, 2018, 72(1), 69). Therefore, glucose in sweat can be used as indirect evidence of changes in blood glucose concentration. - The concentration can be used as a standard for cystic fibrosis (Nature Biotechnology, 2019, 37, 407-419).

[0003] Currently published wearable sweat sensors all use fluid channels to transfer sweat to the surface of the sensor element for detection (Nature Biomedical Engineering, 2022, 6, 1225-1235; Biosensors and Bioelectronics, 2021, 172, 112750). Sweat is not a good cleaning solution. After the measurement, it cannot be guaranteed that there is no residual substance on the surface of the sensor element that affects the detection, which will affect the accuracy and repeatability of long-term monitoring data results, and may lead to a high false alarm rate. Summary of the invention

[0004] In order to improve the defects of the prior art, the present invention provides a cleanable microfluidic platform for a wearable sweat sensor. The advantage of the platform is that a cleanable fluid passage is introduced into the sensor. After the detection is completed, the surface of the sensor element can be cleaned with an external cleaning solvent to ensure that no interfering substances remain on the surface of the sensor element during each detection, thereby providing technical support for the long-term use of the wearable sweat sensor.

[0005] According to one aspect of the present application, a wearable sweat sensor is provided, the wearable sweat sensor comprising a sweat collection layer, a channel layer, a sweat guide layer, a detection layer and a sensor layer;

[0006] The layers are stacked in sequence to obtain the sweat wearable sensor;

[0007] The detection layer comprises a detection pool and a water reservoir;

[0008] The detection pool and the water reservoir are connected via a capillary breakthrough valve;

[0009] The capillary breakthrough valve allows liquid to enter the detection tank from the water reservoir in one direction only;

[0010] The sensor layer is provided with an external interface;

[0011] The external interface is connected to the water reservoir.

[0012] The divergence angle of the capillary breakthrough valve close to the water reservoir is 80-100°;

[0013] The divergence angle of the capillary breakthrough valve on the side close to the detection pool is 10-40 degrees.

[0014] The channel layer and the sweat guiding layer are provided with microfluidic channels;

[0015] The diameter of the microfluidic channel is 50-500 μm.

[0016] The diameter of the detection pool is 50 to 1000 times the diameter of the microfluidic channel;

[0017] The diameter of the detection cell is consistent with the diameter of the sensing element on the sensor layer.

[0018] The diameter of the water reservoir is 200-1000 μm.

[0019] The thickness of any one of the sweat collection layer, channel layer, sweat conduction layer, detection layer or sensor layer is 0.08-0.15 mm.

[0020] The sweat guiding layer is provided with sweat outflow channels, through which liquid can flow out.

[0021] The distance between the capillary breakthrough valve and the detection tank is matched according to the size of the sensor.

[0022] The capillary breakthrough valve is shaped like an arrow, and the arrow points from the water reservoir to the detection reservoir.

[0023] The channel layer is made of polyester.

[0024] The sweat diversion layer and the detection layer are made of hydrophobic adhesive materials.

[0025] According to another aspect of the present application, a method for detecting sweat using the above-mentioned wearable sweat sensor is provided, comprising the following steps:

[0026] Sweat gathers in the sweat gathering layer, enters the detection pool on the detection layer through the microfluidic channels on the channel layer and the sweat guiding layer, contacts the sensing element on the sensing layer, and performs detection. After the detection is completed, the cleaning liquid is passed into the water reservoir on the detection layer through the external interface on the sensing layer, enters the detection pool through the capillary breakthrough valve, and cleans the detection pool and the surface of the sensing element.

[0027] The beneficial effects of this application include:

[0028] 1. In the method of the present invention, the cleanable microfluidic platform introduces a fluid channel that can be externally connected to a cleaning solution without affecting the conduction of sweat to the surface of the sensor element, so as to clean the surface of the sensor element and ensure that no interfering substances remain on the surface of the sensor element.

[0029] 2. The cleanable microfluidic platform in the method of the present invention provides technical support for long-term monitoring of sweat wearable sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the sweat wearable sensor with a clean flow path in device example 1.

[0031] Among them, 1-sweat collection layer, 2-PET layer, 3-sweat diversion layer, 4-detection layer, 5-sensing layer, a-detection pool, b-capillary breakthrough valve, c-water reservoir, d-external interface. DETAILED DESCRIPTION

[0032] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0033] Device example 1

[0034] A cleanable microfluidic platform for wearable sweat sensors, comprising a flow-guiding structure composed of multiple layers of medical double-sided adhesive and PET and a sensing layer with sensing elements. Figure 1As shown, layers 1, 3 and 4 are all medical double-sided adhesives, and layer 2 is a PET layer. Layer 1 is a sweat collection layer, which is close to the skin surface and is used to collect secreted sweat; layer 2 is a sweat diversion channel; layer 3 is a sweat diversion layer, which ensures that the vertically flowing sweat turns to lateral flow; layer 4 is a detection pool layer, which ensures that the sweat is fully in contact with the surface of the sensor element and the detected sweat volume is repeated; layer 5 is a sensing layer, which detects the substances to be tested in sweat. The detection pool a and the water reservoir c located on layer 4 are connected by a capillary breakthrough valve b. The diameter of the detection pool a is 30 mm, covering the entire sensor element. The diameter of the water reservoir c is 10 mm. The capillary breakthrough valve b ensures that the solution flows from the water reservoir c to the detection pool a in a directional manner, with a width of 0.1 mm and a height of 0.1 mm. The emission angle of the capillary breakthrough valve b close to the detection pool a is 13°, and the emission angle close to the water reservoir c is 90°.

[0035] When the sweat test is finished, 0.5 mL of cleaning solvent can be introduced into the water reservoir c through the external interface d. The cleaning solvent flows through the water reservoir c, the capillary breakthrough valve b and the detection pool a in sequence to clean the detection pool and the surface of the sensor element.

[0036] Example 1

[0037] A cleanable microfluidic platform for sweat wearable sensor was described in Example 1 and used to detect 10 μM glucose.

[0038] Without cleaning the surface of the sensor element, the measurement was performed three times in succession, and the results were: 97.3μA, 80.6μA and 65.7μA, respectively. The RSD value of the measurement results was 19.5%.

[0039] The sensor element surface was cleaned using an external cleaning flow path and measured three times in succession, which were: 99.2μA, 92.6μA and 97.4μA. The RSD value of the measurement results was 3.5%.

[0040] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A wearable sweat sensor, characterized in that: The sweat wearable sensor comprises a sweat collection layer, a channel layer, a sweat guide layer, a detection layer and a sensor layer; The layers are stacked in sequence to obtain the sweat wearable sensor; The detection layer comprises a detection pool and a water reservoir; The detection pool and the water reservoir are connected via a capillary breakthrough valve; The capillary breakthrough valve allows liquid to enter the detection tank from the water reservoir in one direction only; The sensor layer is provided with an external interface; The external interface is connected to the water reservoir.

2. The wearable sweat sensor according to claim 1, characterized in that: The divergence angle of the capillary breakthrough valve close to the water reservoir is 80-100 degrees.

3. The wearable sweat sensor according to claim 1, characterized in that: The divergence angle of the capillary breakthrough valve on the side close to the detection pool is 10-40 degrees.

4. The wearable sweat sensor according to claim 1, characterized in that: The channel layer and the sweat guiding layer are provided with microfluidic channels; The diameter of the microfluidic channel is 50-500 μm.

5. The wearable sweat sensor according to claim 1, characterized in that: The diameter of the detection pool is 50 to 1000 times the diameter of the microfluidic channel.

6. The wearable sweat sensor according to claim 1, characterized in that: The diameter of the detection cell is consistent with the diameter of the sensing element on the sensor layer.

7. The wearable sweat sensor according to claim 1, characterized in that: The diameter of the water reservoir is 200-1000 μm.

8. The wearable sweat sensor according to claim 1, characterized in that: The thickness of each of the sweat collection layer, channel layer, sweat conduction layer, detection layer or sensor layer is independently 0.08-0.15 mm.

9. The wearable sweat sensor according to claim 1, characterized in that: The sweat guiding layer is provided with sweat outflow channels, through which liquid can flow out.

10. A method for detecting sweat using the wearable sweat sensor according to any one of claims 1 to 9, characterized in that: The following steps are involved: Sweat gathers in the sweat gathering layer, enters the detection pool on the detection layer through the microfluidic channels on the channel layer and the sweat guiding layer, contacts the sensing element on the sensing layer, and performs detection. After the detection is completed, the cleaning liquid is passed into the water reservoir on the detection layer through the external interface on the sensing layer, enters the detection pool through the capillary breakthrough valve, and cleans the detection pool and the surface of the sensing element.

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