Flexible monitoring patch structure

Abstract

This application discloses a flexible monitoring patch structure, comprising: a flexible substrate layer, wherein the flexible substrate layer is a micro / nano structure; and a detection module, wherein the detection module is disposed on the upper surface of the flexible substrate layer via an elastic connecting layer, the elastic connecting layer being a PDMS material layer, wherein the elastic modulus of the elastic connecting layer near the flexible substrate layer is 1.5-2 MPa, and the elastic modulus of the elastic connecting layer near the detection module is 0.5-0.8 MPa. This invention achieves the connection between the detection layer and the substrate layer through the elastic connecting layer, reducing interfacial shear stress and ensuring the effectiveness of the sensor.

Description

Technical Field

[0001] This application relates to a flexible monitoring patch structure, belonging to the field of electronic patch technology. Background Technology

[0002] With the rapid development of wearable devices and flexible electronics technology, flexible monitoring patches, as an innovative technology that can adhere to the surface of the human body or object and achieve real-time monitoring of multiple parameters, have shown broad application prospects in fields such as medical health, motion monitoring, and human-computer interaction. Existing flexible monitoring patches mostly adopt a layered, stacked structure to integrate different functional layers, while rigid adhesives are used to connect the layers. However, the thermal expansion coefficients of the materials in each layer differ significantly. Under dynamic deformation or temperature changes, the differences in interlayer displacement and thermal conduction lead to prominent mechanical interference and thermal crosstalk problems. Furthermore, traditional rigid adhesives (such as epoxy resin) can cause stress concentration during dynamic deformation of the skin (the elastic modulus of the adhesive (>1 GPa) is much higher than that of the skin (0.1-1 MPa)), leading to sensor failure. Utility Model Content

[0003] According to one aspect of this application, a flexible monitoring patch structure is provided, which connects the detection layer and the substrate layer through an elastic connection layer, reducing interfacial shear stress and ensuring the effectiveness of the sensor.

[0004] A flexible monitoring patch structure, characterized in that it includes:

[0005] A flexible substrate layer, wherein the flexible substrate layer is a micro / nano structure;

[0006] The detection module is disposed on the upper surface of the flexible substrate through an elastic connecting layer. The elastic connecting layer is a PDMS material layer. The elastic modulus of the elastic connecting layer near the flexible substrate is 1.5-2 MPa, and the elastic modulus of the elastic connecting layer near the detection module is 0.5-0.8 MPa.

[0007] Furthermore, the detection module includes a sensor array and a sweat detection unit, which are integrated on the upper surface of the flexible substrate layer via elastic connection layers.

[0008] Furthermore, the sensor array includes a temperature-sensitive unit and a pressure-sensitive unit;

[0009] The temperature-sensitive unit includes a platinum resistance thermometer, the surface of which is coated with polyimide;

[0010] The pressure-sensitive unit is a PDMS / carbon nanotube composite material layer.

[0011] Furthermore, the resistance of the platinum resistance thermometer is 100Ω ± 0.1%.

[0012] The thickness of the PDMS / carbon nanotube composite layer is 50-80 μm.

[0013] Furthermore, the sweat detection unit includes a microfluidic channel and an ion-selective electrode integrated at the bottom center of the microfluidic channel;

[0014] The microfluidic channel is a spiral PDMS channel;

[0015] The ion-selective electrode is an Au / Pt electrode.

[0016] Furthermore, the width of the spiral PDMS channel is 0.4-0.5 mm and the depth is 0.2-0.3 mm.

[0017] Furthermore, it also includes an adhesion reinforcement layer disposed on the lower surface of the flexible substrate layer;

[0018] The bonding reinforcement layer has a double-layer structure. The side of the bonding reinforcement layer closer to the flexible substrate is a polyurethane pressure-sensitive adhesive layer, and the side farther away from the flexible substrate is a breathable non-woven fabric layer.

[0019] Furthermore, the thickness of the polyurethane pressure-sensitive adhesive layer is 26-30 μm.

[0020] Furthermore, the flexible substrate layer is a PET material layer;

[0021] The thickness of the PET material layer is 20-50 μm.

[0022] The beneficial effects that this application can produce include:

[0023] 1) The flexible monitoring patch structure provided in this application achieves the connection between the detection layer and the substrate layer through an elastic connection layer. At the same time, the gradient modulus design of the elastic connection layer effectively alleviates the stress concentration at the interface, improves the durability of the patch under dynamic tension, and ensures the effectiveness of the sensor.

[0024] 2) The flexible monitoring patch structure provided in this application has an adhesion enhancement layer and adopts a composite adhesion structure of carboxyl polyurethane pressure-sensitive adhesive and non-woven fabric to achieve effective adhesion to the skin. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a flexible monitoring patch structure in one embodiment of this application;

[0026] Figure 2 This is a side view of a flexible monitoring patch structure according to one embodiment of this application;

[0027] List of components and reference numerals: 1-Flexible base layer; 2-Elastic connecting layer; 3-Sensor array; 4-Sweat detection unit; 5-Adhesion reinforcement layer. Detailed Implementation

[0028] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0029] See Figure 1-2 A flexible monitoring patch structure, characterized in that it includes:

[0030] Flexible substrate 1, wherein the flexible substrate 1 is a micro / nano structure;

[0031] The detection module is attached to the upper surface of the flexible substrate 1 via an elastic connecting layer 2. The elastic connecting layer 2 is a PDMS material layer. The elastic modulus of the elastic connecting layer 2 on the side closer to the flexible substrate 1 is 1.5-2 MPa, and the elastic modulus of the elastic connecting layer 2 on the side closer to the detection module is 0.5-0.8 MPa.

[0032] Specifically, the flexible substrate layer employs a micro / nano-scale patterned design (such as micropillar arrays and pleated structures) to enhance the adhesion and breathability of the patch at the skin / organ interface, while reducing irritation from long-term application. It is typically an ultra-thin elastic polymer, with a thickness ranging from tens to hundreds of micrometers, balancing flexibility and biocompatibility. The elastic modulus of the elastic connecting layer near the substrate layer is set to 1.5-2 MPa. This high-modulus layer provides structural support, preventing excessive deformation of the patch during movement and ensuring signal transmission stability. The elastic modulus near the detection module is 0.5-0.8 MPa. This low-modulus layer buffers stress, preventing damage to the detection module due to substrate deformation, while also improving adhesion to complex curved surfaces (such as joints and skin folds). This can be achieved through a two-layer co-curing or gradient concentration PDMS spin-coating process, where the modulus difference originates from the crosslinking agent ratio or curing temperature gradient. The detection module can integrate strain sensors (such as carbon nanotubes / graphene-based sensors), temperature sensors (thermometers), and pressure sensors (capacitive / piezoresistive) for real-time monitoring of physiological signals (such as pulse, respiration, and muscle electrical activity). A reliable interface must be formed with the elastic bonding layer to avoid delamination; in practical applications, this can be achieved using embedded packaging or a flexible printed circuit board (FPCB).

[0033] Furthermore, the gradient modulus design of PDMS can effectively alleviate interfacial stress concentration and improve the durability of the patch under dynamic tension (such as joint bending). The low-modulus layer can absorb high-frequency vibration interference, improving the sensor's detection accuracy for low-amplitude physiological signals (such as microvolt-level ECG signals). The micro-nano structure of the flexible substrate can reduce sweat accumulation on the skin surface, reduce the risk of allergies, and is suitable for long-term wear (>7 days). It can also enhance van der Waals forces or introduce chemical bonding through surface modification (such as plasma treatment) to achieve adhesive-free adhesion.

[0034] The detection module includes a sensor array 3 and a sweat detection unit 4, which are respectively attached to the upper surface of the flexible substrate layer 1 through an elastic connecting layer 2.

[0035] Specifically, sensor array 3 primarily uses physical signals (strain, pressure, temperature, electromyography / electrocardiography, etc.) to achieve spatially resolved monitoring of physiological parameters (such as joint movement trajectory and muscle force distribution). Sweat detection unit 4 focuses on chemical signals (ion concentration, metabolites, drug molecules, etc.) and utilizes microfluidic or electrochemical sensing technology to achieve non-invasive biomarker analysis (such as glucose, lactic acid, and cortisol). Sensor array 3 and sweat detection unit 4 can be distributed in different areas of the patch to avoid interference from sweat diffusion on the physical sensors and optimize the signal acquisition path.

[0036] The sensor array 3 includes a temperature-sensitive unit and a pressure-sensitive unit;

[0037] The temperature-sensitive unit includes a platinum resistance thermometer, the surface of which is coated with polyimide;

[0038] The pressure-sensitive unit is a PDMS / carbon nanotube composite material layer.

[0039] Furthermore, platinum resistance thermometers (Pt100 / Pt1000) utilize the linear temperature-dependent resistivity of metals (TCR≈0.00385 / ℃) to infer temperature by measuring resistance. They feature high accuracy, wide measurement range, and good long-term stability, making them suitable for medical-grade body temperature monitoring. A polyimide (PI) coating prevents short circuits between the platinum resistance thermometer and a flexible substrate or sweat (PI dielectric strength >150kV / mm), conforming to ISO 10993 standards and avoiding skin irritation or allergic reactions. This enhances the fatigue resistance of the platinum resistance thermometer (resistance change <0.05% under 10% tensile deformation), adapting to dynamic skin deformation; PDMS provides flexibility and biocompatibility. Carbon nanotubes can be used as conductive fillers to form a three-dimensional conductive network. Under pressure, the PDMS matrix deforms, causing changes in the spacing between carbon nanotubes and altering the resistivity. Surface modification improves the interfacial bonding strength between SWCNTs and PDMS, reducing resistance drift under cyclic loading.

[0040] It is worth noting that polydimethylsiloxane (PDMS) is a type of organosilicon. Due to its low cost, ease of use, good adhesion to silicon wafers, and good chemical inertness, it has become a widely used polymer material in fields such as microfluidics. Carbon nanotubes are seamless nanotube structures formed by rolling single or multiple layers of graphite sheets around a central axis at a certain helical angle. The ends are open or sealed by hemispherical fullerene molecules. Each tube wall is a cylindrical surface formed by a hexagonal network plane composed of carbon atoms fully bonded to three surrounding carbon atoms through sp2 hybridization. The spacing between the tube walls is approximately 0.34 nm. Based on the number of tube wall layers, carbon nanotubes (CNTs) can be divided into single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs). CNTs have an electrical conductivity of up to 10⁶ S / cm, making them excellent conductive fillers.

[0041] The resistance of the platinum resistance thermometer is 100Ω ± 0.1%.

[0042] The thickness of the PDMS / carbon nanotube composite layer is 50-80 μm.

[0043] Specifically, through the synergistic design of high-precision platinum resistance thermometers and gradient-structured PDMS / carbon nanotube composite layers, precise capture and long-term stable monitoring of temperature and pressure signals were achieved.

[0044] The sweat detection unit 4 includes a microfluidic channel and an ion-selective electrode integrated at the bottom center of the microfluidic channel;

[0045] The microfluidic channel is a spiral PDMS channel;

[0046] The ion-selective electrode is an Au / Pt electrode.

[0047] The spiral structure PDMS channel has a width of 0.4-0.5 mm and a depth of 0.2-0.3 mm.

[0048] Specifically, the fluid in the spiral channel generates a secondary flow due to the Coriolis force, promoting the mixing of sweat and the detection reagent. The residence time of sweat is controlled by adjusting the spiral spacing to accommodate different ions (such as Na+). + K + Cl - The diffusion equilibrium requirement is met. Plasma treatment of the PDMS channel reduces non-specific protein adsorption and avoids detection signal drift.

[0049] The Au substrate provides high conductivity and chemical stability, while also serving as a stable interface for ion-electron conversion. The Pt functional layer forms a nanodendritic structure through pulsed electrodeposition, enabling K... + The sensitivity of the selected electrode is improved.

[0050] It also includes an adhesion reinforcement layer 5, which is disposed on the lower surface of the flexible substrate layer 1;

[0051] The bonding reinforcement layer 5 has a double-layer structure. The side of the bonding reinforcement layer 5 closest to the flexible substrate layer 1 is a polyurethane pressure-sensitive adhesive layer, and the side away from the flexible substrate layer 1 is a breathable non-woven fabric layer.

[0052] The thickness of the polyurethane pressure-sensitive adhesive layer is 26-30 μm.

[0053] Specifically, polyurethane pressure-sensitive adhesive is a self-adhesive material. It is a type of adhesive that does not require solvents, heat, or other means; it only needs to apply light pressure to form a strong bond. After the adhesive layer is formed, its structure remains intact. The bonding force between two solid surfaces is mainly van der Waals force. Its characteristics include easy adhesion and removal, and the adhesive layer does not dry out over a relatively long period. A breathable non-woven fabric layer covers the polyurethane pressure-sensitive layer before use. During use, the breathable non-woven fabric layer is removed, and the polyurethane pressure-sensitive layer is then applied to the skin for the corresponding test.

[0054] The flexible substrate layer 1 is a PET material layer;

[0055] The thickness of the PET material layer is 20-50 μm.

[0056] Specifically, PET (polyethylene terephthalate) is a milky white or light yellow, highly crystalline polymer with a smooth and glossy surface. It exhibits good creep resistance, fatigue resistance, abrasion resistance, and dimensional stability, with low wear and high hardness. It possesses the highest toughness among thermoplastics, good electrical insulation properties (Q), and is minimally affected by temperature. Flexible PET substrates with a thickness of 20-50 μm, through structural design optimization, have achieved multi-scenario coverage, from medical wearables to flexible electronic displays.

[0057] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A flexible monitoring patch structure, characterized by include: A flexible substrate layer (1) is a micro / nano structure; The detection module is disposed on the upper surface of the flexible substrate (1) through an elastic connecting layer (2). The elastic connecting layer (2) is a PDMS material layer. The elastic modulus of the elastic connecting layer (2) on the side closer to the flexible substrate (1) is 1.5-2 MPa, and the elastic modulus of the elastic connecting layer (2) on the side closer to the detection module is 0.5-0.8 MPa.

2. The flexible monitoring patch structure of claim 1, wherein, The detection module includes a sensor array (3) and a sweat detection unit (4), which are integrated on the upper surface of the flexible substrate layer (1) through an elastic connection layer (2).

3. The flexible monitoring patch structure of claim 2, wherein, The sensor array (3) includes a temperature-sensitive unit and a pressure-sensitive unit; The temperature-sensitive unit includes a platinum resistance thermometer, the surface of which is coated with polyimide; The pressure-sensitive unit is a PDMS / carbon nanotube composite material layer.

4. The flexible monitoring patch structure of claim 3, wherein, The resistance of the platinum resistance thermometer is 100Ω ± 0.1%. The thickness of the PDMS / carbon nanotube composite layer is 50-80 μm.

5. The flexible monitoring patch structure of claim 2, wherein, The sweat detection unit (4) includes a microfluidic channel and an ion-selective electrode integrated at the bottom center of the microfluidic channel; The microfluidic channel is a spiral PDMS channel; The ion-selective electrode is an Au / Pt electrode.

6. The flexible monitoring patch structure of claim 5, wherein, The spiral structure PDMS channel has a width of 0.4-0.5 mm and a depth of 0.2-0.3 mm.

7. The flexible monitoring patch structure of claim 1, wherein, It also includes an adhesion reinforcement layer (5), which is disposed on the lower surface of the flexible substrate layer (1); The bonding reinforcement layer (5) has a double-layer structure. The side of the bonding reinforcement layer (5) closer to the flexible substrate layer (1) is a polyurethane pressure-sensitive adhesive layer, and the side away from the flexible substrate layer (1) is a breathable non-woven fabric layer.

8. The flexible monitoring patch structure of claim 7, wherein, The thickness of the polyurethane pressure-sensitive adhesive layer is 26-30 μm.

9. The flexible monitoring patch structure of claim 1, wherein, The flexible substrate layer (1) is a PET material layer; The thickness of the PET material layer is 20-50 μm.

Images