A longitudinally integrated dual-mode decoupled respiration monitoring sensor and method of manufacture
By designing a vertically homogeneous integrated sensor and employing water-induced interface fusion technology, the problems of conformal adhesion of the sensor to human skin and signal decoupling were solved. This enabled independent acquisition and precise decoupling of temperature, humidity, pressure, and position signals, improving the accuracy and stability of respiratory monitoring and reducing manufacturing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JILIN UNIVERSITY
- Filing Date
- 2026-04-30
- Publication Date
- 2026-06-02
AI Technical Summary
Existing vertically integrated respiratory monitoring sensors lack conformal adhesion and flexibility to human skin, making it difficult to achieve independent acquisition and accurate decoupling of temperature, humidity, pressure, and position signals. This results in signal crosstalk and coupling interference, affecting monitoring accuracy and stability. Furthermore, the high manufacturing cost makes it difficult to meet the requirements of green manufacturing.
A vertically homogeneous integrated configuration is adopted. Temperature-sensitive, humidity-sensitive, and stress-sensitive sensing units are alternately stacked with fiber-based interface barrier films through a water-induced interface fusion strategy to form a sandwich-like configuration. The conductivity is improved by using reduced graphene oxide and multi-walled carbon nanotube composite materials, and signal decoupling is achieved by combining random forest algorithm.
It significantly reduces the false alarm rate of monitoring, improves the reliability and anti-interference ability of respiratory monitoring, enhances signal analysis accuracy and long-term stability, reduces manufacturing costs, and meets the needs of accurate monitoring in complex scenarios.
Smart Images
Figure CN122123679A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of vertically integrated flexible sensor technology, and particularly relates to a vertically integrated dual-mode decoupled respiratory monitoring sensor and its preparation method. Background Technology
[0002] Respiratory monitoring is a crucial aspect of wearable health monitoring, and accurate respiratory signal acquisition and analysis are essential for human health assessment and disease early warning. Integrated sensors are commonly used sensing devices in the field of intelligent sensing. They utilize changes in the electrical signals of multiple sensing units to achieve visual identification of external stimuli such as stress, temperature, or humidity, providing a technological foundation for multi-parameter monitoring of respiratory signals. However, existing integrated sensing systems for respiratory monitoring mostly rely on processes such as printed circuit boards, screen printing, or inkjet printing to achieve horizontal integration of multiple sensing units in a two-dimensional plane. While this approach offers good technological maturity and lateral scalability, the lack of effective physical or electrical isolation mechanisms makes it prone to signal crosstalk and coupling interference between different functional units. This prevents the independent acquisition of temperature, humidity, pressure, and position signals during respiratory monitoring, severely impacting the accuracy of respiratory signal analysis and limiting its application in complex respiratory monitoring scenarios.
[0003] To overcome the inherent limitations of two-dimensional integration and improve the accuracy and integration density of respiratory monitoring devices, research has gradually shifted towards three-dimensional vertical integration strategies. Methods such as magnetron sputtering, electron beam evaporation, electron patching, or soft soldering can stack different sensing units vertically, significantly increasing the functional density of the device. However, current vertically integrated sensors employ multi-layer heterogeneous stacking, leading to increased device thickness, reduced flexibility, difficulty in conformal adhesion to human skin, and susceptibility to interfacial stress and signal drift caused by dynamic deformation induced by respiration, affecting the stability of respiratory signal monitoring. Furthermore, the single-response mechanism of existing vertically integrated respiratory monitoring sensors struggles to handle the coupled interpretation of multiple physical stimuli, failing to achieve effective decoupling of dual-mode signals, further reducing the accuracy of respiratory signal monitoring. In addition, the integration layers are mostly physically contacted or weakly bonded, resulting in insufficient long-term stability and susceptibility to delamination and failure. Moreover, complex processing and packaging processes not only increase manufacturing costs but also fail to meet the application requirements of green manufacturing.
[0004] In recent years, the rapid development of flexible electronics technology has profoundly reshaped intelligent sensing systems. With its excellent flexibility, stretchability, and conformal attachment capabilities, flexible longitudinally integrated sensors have shown broad application prospects in fields such as intelligent bionics, wearable medical devices, and human-computer interaction. However, in real-world applications of human respiration monitoring, sensors face challenges such as the complex curved surfaces of human skin, dynamic deformation during respiration, and multi-physics coupling environments. This places higher demands on the stability, reliability, and signal resolution capabilities of the sensors.
[0005] In summary, achieving simultaneous sensing and precise decoupling of temperature / humidity and pressure / position dual-modal signals during respiration monitoring while ensuring good mechanical adaptability and conformal adhesion to human skin, thereby improving the accuracy and long-term stability of respiratory signal monitoring and reducing manufacturing costs, has become a key scientific issue for the practical application of flexible integrated devices. Therefore, there is an urgent need to develop flexible, longitudinally integrated respiratory monitoring sensors and their fabrication methods that combine high spatial resolution and multi-parameter collaborative sensing to address the shortcomings of existing technologies. Summary of the Invention
[0006] The purpose of this invention is to provide a longitudinally integrated dual-mode decoupled respiratory monitoring sensor and its fabrication method, aiming to solve the problems mentioned in the background art.
[0007] The present invention is implemented as follows: a longitudinally integrated dual-mode decoupled respiratory monitoring sensor, which is a fiber-based flexible multimodal integrated device, adopts a longitudinally homogeneous integration configuration, and includes:
[0008] Multiple dual-conductive material sensing units, including a temperature-sensitive sensing unit, a humidity-sensitive sensing unit, and a stress-sensitive sensing unit, wherein the temperature-sensitive sensing unit, humidity-sensitive sensing unit, and stress-sensitive sensing unit are formed into different geometric configurations by laser cutting of the same dual-conductive material fiber-based flexible polymer film;
[0009] A fiber-based interface barrier film, wherein the fiber-based interface barrier film is composed of an insulating fiber-based flexible polymer film;
[0010] The humidity-sensitive sensing unit, temperature-sensitive sensing unit, stress-sensitive sensing unit, and fiber-based interface barrier film are alternately stacked and homogeneously integrated in the vertical direction through water induction. The fiber-based interface barrier film is located between adjacent sensing units, forming a sandwich-like configuration with functional units spaced apart.
[0011] In a further technical solution, the conductive material of the dual-conductive fiber-based flexible polymer film is a composite system of reduced graphene oxide and multi-walled carbon nanotubes.
[0012] In a further technical solution, the mass ratio of the reduced graphene oxide to the multi-walled carbon nanotubes is 1:3.
[0013] In a further technical solution, the temperature-sensitive sensing unit has a serpentine structure, the humidity-sensitive sensing unit has a complementary serpentine structure, and the stress-sensitive sensing unit has a square structure.
[0014] In a further technical solution, the fiber-based interface barrier film is composed of cellulose nanofibers and polyvinyl alcohol.
[0015] Another objective of this invention is to provide a method for fabricating a longitudinally integrated dual-mode decoupled respiratory monitoring sensor, comprising the following steps:
[0016] Step 1: Fabrication of fiber-based flexible sensing film;
[0017] A uniform mixture containing reduced graphene oxide, multi-walled carbon nanotubes, cellulose nanofibers and polyvinyl alcohol was prepared, and a film was formed by casting. After drying, a fiber-based flexible polymer film with dual conductive materials was obtained.
[0018] Step 2: Fabrication of multimodal sensing units;
[0019] Using laser cutting technology, the double conductive material fiber-based flexible polymer film obtained in step 1 is cut into temperature-sensitive sensing units, humidity-sensitive sensing units and stress-sensitive sensing units with different preset configurations. Conductive silver paste is coated on the preset electrode sites of each unit and cured to form independent signal acquisition channels.
[0020] Step 3: Preparation of fiber-based interfacial barrier layer;
[0021] A uniform mixture containing cellulose nanofibers and polyvinyl alcohol was prepared, and a film was formed by casting. After drying, a fiber-based interfacial barrier flexible polymer film was obtained and cut into a predetermined shape.
[0022] Step 4: Vertical stacking and integration of fiber-based sensors;
[0023] A water-induced interface fusion strategy was adopted, in which deionized water was uniformly coated on the surface of each sensing unit prepared in step 2 and the fiber-based interface barrier flexible polymer film prepared in step 3. Then, the layers were stacked alternately in a preset order and allowed to stand at room temperature to allow the solvent to evaporate, and an intrinsic fusion interface was formed between the layers to obtain a longitudinally integrated dual-mode decoupled respiratory monitoring sensor.
[0024] The present invention provides a longitudinally integrated dual-mode decoupled respiratory monitoring sensor and its fabrication method, the beneficial effects of which are as follows:
[0025] (1) By cross-validating multi-mode respiratory monitoring and multi-dimensional signals, the monitoring error rate is significantly reduced, and the reliability and anti-interference ability of respiratory monitoring in complex wearable scenarios are improved.
[0026] (2) Based on the random forest algorithm, the temperature, humidity and pressure dual-mode signals are decoupled without crosstalk, which solves the problem of multi-physical field signal coupling distortion and improves the fidelity and analytical accuracy of respiratory monitoring data;
[0027] (3) A one-dimensional multi-walled carbon nanotube and two-dimensional reduced graphene oxide composite conductive system is adopted and combined with a fiber-based flexible substrate to synergistically optimize the conductivity and flexible adhesion performance of the device.
[0028] (4) The water-induced interface fusion homogeneous integration process is adopted. The preparation process is green and low-cost, and the interlayer bonding is strong, which enables the sensor to have good long-term stability and mass production potential. Attached Figure Description
[0029] Figure 1 A flowchart illustrating a method for fabricating a longitudinally integrated dual-mode decoupled respiratory monitoring sensor according to an embodiment of the present invention;
[0030] Figure 2 This is a schematic diagram of the structure of a longitudinally integrated dual-mode decoupled respiratory monitoring sensor provided in an embodiment of the present invention;
[0031] Figure 3 This is a framework diagram of a wireless physiological respiration monitoring system.
[0032] Figure 4 Error bar experimental plot showing the correspondence between the resistance changes of different sensing units and different physiological breathing patterns;
[0033] Figure 5 This is a schematic diagram of a dual-mode press test;
[0034] Figure 6 This is a diagram showing the results of the machine learning-based dual-mode decoupled classification.
[0035] In the attached diagram: humidity sensing unit 1; temperature sensing unit 2; stress sensing unit 3; fiber-based interface barrier film 4. Detailed Implementation
[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0037] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.
[0038] like Figure 2 As shown, an embodiment of the present invention provides a longitudinally integrated dual-mode decoupled respiratory monitoring sensor, which is a fiber-based flexible multimodal integrated device composed of a dual conductive material sensing unit with multiple shape scales and a fiber-based interface barrier film, specifically including:
[0039] The system comprises a serpentine complementary humidity sensing unit 1, a serpentine temperature sensing unit 2, a square stress sensing unit 3, and a square fiber-based interface barrier film 4. Each sensing unit (i.e., humidity sensing unit 1, temperature sensing unit 2, and stress sensing unit 3) is formed into different geometric configurations by laser cutting from the same dual-conductive fiber-based flexible polymer film. The fiber-based interface barrier film 4 is composed of an insulating fiber-based flexible polymer film.
[0040] In the vertical stacking direction, the humidity-sensitive sensing unit 1, temperature-sensitive sensing unit 2, stress-sensitive sensing unit 3, and fiber-based interface barrier film 4 are alternately stacked and homogeneously integrated in the vertical direction through water-induced effects. Specifically, the fiber-based interface barrier film 4 is located between adjacent sensing units, forming an alternating distribution structure of "sensing unit-barrier layer-sensing unit," and the whole structure constitutes a sandwich-like configuration with spaced functional units. This structural design effectively blocks signal crosstalk between different sensing units from both physical and electrical perspectives, ensuring independent acquisition and accurate analysis of dual-mode signals.
[0041] like Figure 1 As shown, another embodiment of the present invention provides a method for fabricating a longitudinally integrated dual-mode decoupled respiratory monitoring sensor, which is achieved through the following process:
[0042] Step 1: Preparation of a flexible polymer film based on dual conductive materials fiber;
[0043] Step 1.1: Preparation of a uniform suspension based on dual-conductive material fibers;
[0044] 8 mL of a 1.2 wt% cellulose nanofiber suspension and 20 mL of deionized water were poured into a clean glass bottle, sealed with a magnetic stir bar, and stirred at room temperature until the system was homogeneous, yielding a cellulose nanofiber aqueous suspension. Reduced graphene oxide and multi-walled carbon nanotubes (MWCNTs) were weighed at a mass ratio of 1:3, totaling 1 g, and added to the above aqueous suspension. The bottle was sealed and stirred at 800 r / min at room temperature for at least 24 h, followed by ultrasonic treatment for 30 min, to obtain a homogeneous mixture of reduced graphene oxide, MWCNTs, and cellulose nanofibers. This mixture was continuously stirred for later use.
[0045] Step 1.2: Preparation of a flexible polymer film based on dual conductive materials fiber;
[0046] Add 1.85 g of polyvinyl alcohol to the mixture obtained in step 1.1, stir at room temperature for 30 min under sealed conditions, and then stir in a 95°C water bath for 6 h. Prepare a 100 mm diameter circular glass container, wipe it clean with anhydrous ethanol and dry it thoroughly. Pour 20 g of the above mixture evenly onto a flat glass plate using a casting method, and place it in an oven at 45°C without airflow to dry until the polymer solution no longer flows. Then place it at room temperature until the solvent evaporates and forms a film, finally obtaining a fiber-based flexible polymer film with dual conductive materials.
[0047] Step 2: Fabrication of multimodal sensing units;
[0048] Step 2.1: Fabrication of the temperature-sensitive sensing unit;
[0049] A serpentine structure was cut from a fiber-based flexible polymer film with dual conductive materials using a laser cutter to serve as a temperature-sensitive sensing unit 2. Conductive silver paste was coated on the preset electrode sites and cured by heating at 60°C for 5 min to prepare an independent temperature-sensitive signal acquisition channel for later use.
[0050] Step 2.2: Fabrication of the humidity-sensitive sensing unit;
[0051] A serpentine complementary structure was cut into a fiber-based flexible polymer film with dual conductive materials using a laser cutting machine to serve as a humidity sensing unit 1. Conductive silver paste was coated on the preset electrode sites and cured by heating at 60°C for 5 min to prepare an independent humidity signal acquisition channel for later use.
[0052] Step 2.3: Fabrication of the stress sensing unit;
[0053] A rectangular structure was cut from a fiber-based flexible polymer film with dual conductive materials using a laser cutter to serve as a stress sensing unit 3. Conductive silver paste was coated on the preset electrode sites and cured by heating at 60°C for 5 minutes to prepare an independent pressure-sensitive signal acquisition channel for later use.
[0054] Step 3: Preparation of fiber-based interface barrier film 4;
[0055] Step 3.1: Preparation of the barrier layer polymer mixture;
[0056] 8 mL of a 1.2 wt% cellulose nanofiber suspension and 20 mL of deionized water were poured into a clean glass bottle and stirred at room temperature until homogeneous to obtain an aqueous suspension of cellulose nanofibers. 1.85 g of polyvinyl alcohol was added, the bottle was sealed, and stirred at room temperature for 30 min. The mixture was then stirred in a water bath at 95°C for 6 h. The solution was allowed to cool before use.
[0057] Step 3.2: Preparation of fiber-based interfacial barrier film 4;
[0058] Take a 100 mm diameter circular glass container, wipe it clean with anhydrous ethanol and dry it thoroughly. Use the casting method to evenly pour 20 g of the above barrier layer polymer mixture solution onto a flat glass plate, place it in an oven at 45°C without wind and dry until the polymer solution no longer flows. Then place it at room temperature until the solvent evaporates and forms a film, finally obtaining a fiber-based interface barrier flexible polymer film. Cut the fiber-based interface barrier flexible polymer film into standard squares as fiber-based interface barrier film 4 for later use.
[0059] Step 4: Vertical stacking and integration of fiber-based sensors;
[0060] A water-induced interface fusion strategy was adopted, using deionized water as the molecular bridging medium, which was uniformly coated on the surfaces of humidity-sensitive sensing unit 1, temperature-sensitive sensing unit 2, stress-sensitive sensing unit 3, and fiber-based interface barrier film 4. Utilizing the water-induced effect, each layer was uniformly covered during longitudinal stacking, and stacked alternately in a preset order to form close contact, ensuring that each layer was aligned, tightly bonded, and free of misalignment and air bubbles. After standing at room temperature, the solvent slowly evaporated, forming a stable intrinsic fusion interface between the layers, ultimately constructing a multimodal longitudinally integrated sensor with an intrinsic fusion interface, namely a longitudinally integrated dual-mode decoupled respiratory monitoring sensor.
[0061] Step 5: Performance Testing
[0062] Step 5.1: Multimodal respiratory monitoring performance test;
[0063] The vertically integrated dual-mode decoupled respiratory monitoring sensor incorporates three independent sensing channels, each with a different response mechanism, providing independent responses to multi-mode physiological respiratory signals. By integrating the differential responses and synergistic signal coupling mechanisms of each sensing layer, it achieves multi-dimensional cross-validation and high-precision monitoring of respiratory activity. Figure 3 As shown, a physiological respiratory wireless monitoring system is used to acquire the resistance signals of each sensing layer in real time. Under deep breathing, shallow breathing, and rapid breathing modes, the resistance of humidity-sensitive sensing unit 1, temperature-sensitive sensing unit 2, and stress-sensitive sensing unit 3 all exhibit specific changes. These signals are transmitted to a computer via Bluetooth, enabling real-time visualization and synchronous recording of the respiratory waveform. The rate of resistance change between each layer under different breathing modes is measured and calculated. ,in This represents the change in resistance of the sensing unit (during the breathing process). The initial resistance of the sensing unit (before respiration) was used. Each experiment was repeated eight times, and the experimental results were calculated as follows: Figure 4 The figure shows error bars illustrating the relationship between the resistance change rate of the three sensing units and different breathing modes. This experimental result demonstrates that the longitudinally integrated dual-mode decoupled respiratory monitoring sensor can accurately identify different breathing modes and achieve cross-validation of multiple breathing modes based on the different response mechanisms of the sensing units across multiple levels.
[0064] Step 5.2: Signal decoupling and classification test under dual-mode coupled stimulation;
[0065] like Figure 5 The diagram shows a test illustration of temperature-sensitive sensing unit 2 and humidity-sensitive sensing unit 1 under dual-mode coupled stimulation conditions. A classification model is constructed using the random forest algorithm to complete dual-mode sensing and signal decoupling of temperature-pressure position and humidity-pressure position.
[0066] (1) Temperature-pressure position dual-modal sensing: The resistance response of the temperature-sensitive sensing unit 2 under pressure at three specific positions (to the left, middle and right of the positive terminal connection point) was recorded using a digital multimeter. The test temperature conditions covered high temperature (70℃), medium temperature (40℃) and room temperature. The resistance noise and resistance change rate of the temperature-sensitive sensing unit 2 at multiple positions under gradient temperatures (70℃, 40℃ and room temperature) were used as characteristic parameters.
[0067] (2) Humidity-pressure position dual-modal sensing: The resistance response of the humidity sensing unit 1 under pressure at three specific positions (left, middle and right relative to the positive terminal connection point) was recorded using a digital multimeter. The corresponding humidity conditions covered fully wet fingers, slightly wet fingers and dry fingers. The resistance noise and resistance change rate of the humidity sensing unit 1 at multiple positions under gradient humidity (fully wet fingers, slightly wet fingers, dry fingers) were used as characteristic parameters.
[0068] Each state was captured for 3.5 seconds. The resulting dataset was then divided into training and test sets in an 80% to 20% ratio. Figure 6 As shown, the final comprehensive classification accuracy of the temperature-location and humidity-location dual-modal signals reached 96.79% and 99.80%, respectively. This experimental result demonstrates that the sensor described in this invention can accurately identify temperature-location and humidity-location dual-modal signals, achieving high-precision dual-modal sensing and signal decoupling.
[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A longitudinally integrated dual-mode decoupled respiratory monitoring sensor, characterized in that, include: Multiple dual-conductive material sensing units, including a temperature-sensitive sensing unit, a humidity-sensitive sensing unit, and a stress-sensitive sensing unit, wherein the temperature-sensitive sensing unit, humidity-sensitive sensing unit, and stress-sensitive sensing unit are formed into different geometric configurations by laser cutting of the same dual-conductive material fiber-based flexible polymer film; A fiber-based interface barrier film, wherein the fiber-based interface barrier film is composed of an insulating fiber-based flexible polymer film; The humidity-sensitive sensing unit, temperature-sensitive sensing unit, stress-sensitive sensing unit, and fiber-based interface barrier film are alternately stacked and homogeneously integrated in the vertical direction through water induction. The fiber-based interface barrier film is located between adjacent sensing units, forming a sandwich-like configuration with functional units spaced apart.
2. The longitudinally integrated dual-mode decoupled respiratory monitoring sensor according to claim 1, characterized in that, The conductive material of the fiber-based flexible polymer film with dual conductive materials is a composite system of reduced graphene oxide and multi-walled carbon nanotubes.
3. The longitudinally integrated dual-mode decoupled respiratory monitoring sensor according to claim 2, characterized in that, The mass ratio of the reduced graphene oxide to the multi-walled carbon nanotubes is 1:
3.
4. The longitudinally integrated dual-mode decoupled respiratory monitoring sensor according to claim 1, characterized in that, The temperature-sensitive sensing unit has a serpentine structure, the humidity-sensitive sensing unit has a complementary serpentine structure, and the stress-sensitive sensing unit has a square structure.
5. The longitudinally integrated dual-mode decoupled respiratory monitoring sensor according to claim 1, characterized in that, The fiber-based interface barrier film is composed of cellulose nanofibers and polyvinyl alcohol.
6. A method for fabricating a longitudinally integrated dual-mode decoupled respiratory monitoring sensor as described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Fabrication of fiber-based flexible sensing film; A uniform mixture containing reduced graphene oxide, multi-walled carbon nanotubes, cellulose nanofibers and polyvinyl alcohol was prepared, and a film was formed by casting. After drying, a fiber-based flexible polymer film with dual conductive materials was obtained. Step 2: Fabrication of multimodal sensing units; Using laser cutting technology, the double conductive material fiber-based flexible polymer film obtained in step 1 is cut into temperature-sensitive sensing units, humidity-sensitive sensing units and stress-sensitive sensing units with different preset configurations. Conductive silver paste is coated on the preset electrode sites of each unit and cured to form independent signal acquisition channels. Step 3: Preparation of fiber-based interfacial barrier layer; A uniform mixture containing cellulose nanofibers and polyvinyl alcohol was prepared, and a film was formed by casting. After drying, a fiber-based interfacial barrier flexible polymer film was obtained and cut into a predetermined shape. Step 4: Vertical stacking and integration of fiber-based sensors; A water-induced interface fusion strategy was adopted, in which deionized water was uniformly coated on the surface of each sensing unit prepared in step 2 and the fiber-based interface barrier flexible polymer film prepared in step 3. Then, the layers were stacked alternately in a preset order and allowed to stand at room temperature to allow the solvent to evaporate, and an intrinsic fusion interface was formed between the layers to obtain a longitudinally integrated dual-mode decoupled respiratory monitoring sensor.