Preparation method and application of self-packaging stretching type multimode sensor

Abstract

The invention relates to a preparation method and application of a self-packaging stretching type multi-mode sensor, in particular to a processing method for preparing self-adhesive, stretchable, multi-mode, double-layer or multi-layer stacked sensor hardware based on 3D printing, and aims to solve the problems that a rigid sensor cannot be attached to a human body, measurement of a single sensor is inaccurate and the like. And meanwhile, the flexible stretching of a multi-mode and multi-layer sensor is realized, the measurement of the sensor in the aspect of fine movement of limbs is realized, the full-flexible batch preparation condition is met, and the application requirements of the sensor in specific occasions such as physical exercise are met.

Description

Technical Field

[0001] This invention belongs to the field of sensor technology, specifically relating to a method for preparing and applying a self-encapsulated stretchable multimode sensor. Background Technology

[0002] With the development of embodied intelligence, precise motion monitoring has become an important tool for improving athletic performance, optimizing sports health, and advancing rehabilitation medicine. Current mainstream bio-motion information acquisition technologies mainly include visual and inertial technologies.

[0003] Specifically, camera-based vision technology offers high precision, non-contact tracking, and multi-target simultaneous tracking capabilities. However, this technology relies on fixed locations and lighting conditions, making it difficult to capture the movement trajectory of obscured areas and posing privacy and security risks. In contrast, inertial measurement unit (IMU) technology, which uses rigid sensors, is highly portable, suitable for outdoor use, and provides acceleration and angular velocity data. However, the rigid material may cause discomfort when worn, and long-term use can lead to motion artifacts and data drift due to poor skin adhesion.

[0004] While existing flexible or stretchable sensors achieve close adhesion to human skin and reduce motion artifacts, they still face problems such as poor interface reliability, easy disconnection of connecting wires, and limited functionality to monitoring. Summary of the Invention

[0005] This invention proposes a method for fabricating and applying a self-encapsulated stretchable multimode sensor, mainly solving the following technical problems: (1) Current camera technology used to monitor sports relies on fixed locations and lighting conditions and is too expensive.

[0006] (2) The rigid sensor IMU currently worn on the body is prone to motion artifacts and poor adhesion to the skin.

[0007] (3) Currently, the interface of flexible sensors is unstable and prone to signal disturbance, and single sensor monitoring is inaccurate and multi-functional integration is difficult.

[0008] This invention enables real-time and accurate monitoring of biological limb movements. To address the aforementioned technical problems, this invention provides a method for fabricating and applying a self-encapsulated stretchable multimode sensor.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a self-encapsulated stretchable multimode sensor, comprising a flexible stretchable film substrate, a capacitive strain sensor, and a bioelectrode connected in sequence. The capacitive strain sensor is used to monitor strain signals, and the bioelectrode is used to monitor electromyographic signals. The capacitive strain sensor and the bioelectrode are integrated onto the flexible stretchable film substrate by means of an array electrode pattern or an interdigitated electrode pattern. The conductive interfaces of the capacitive strain sensor and the bioelectrode are encapsulated on the flexible stretchable film substrate by means of a conductive paste and a flexible conductive tape.

[0010] Furthermore, one or more of the following are provided between the flexible stretchable film substrate and the capacitive strain sensor: a temperature sensor, a humidity sensor, and a resistance sensor.

[0011] Furthermore, the flexible stretchable film substrate is composed of a stretchable polymer film and an adhesive film; wherein, the stretchable polymer film includes one or more flexible stretchable materials selected from polydimethylsiloxane (PDMS), thermoplastic polyurethane (TPU), and thermoplastic polyethylene (TPE); the adhesive film includes one or more flexible adhesives selected from medical acrylic pressure-sensitive adhesive (PSA), silicone pressure-sensitive adhesive (Silicone PSA), hydrocolloid adhesive, polyurethane-based adhesive (PU-based Adhesive), and hot melt adhesive (HMA). The adhesive film is used to achieve the self-adhesion of this self-encapsulated stretchable multimode sensor.

[0012] The present invention also provides a method for fabricating the above-mentioned self-encapsulated stretchable multimode sensor, the method comprising the following steps: Step 1, preparing a flexible stretchable film substrate; Step 2, designing strain sensor patterns for a capacitive strain sensor and electrode patterns for a bioelectrode, respectively, obtaining patterns required by a printing device and exporting them in a file format suitable for the printing device; Step 3, importing the patterns into a printing device, and performing 3D printing on the flexible stretchable film substrate using conductive silver paste and carbon paste to obtain the printed sensor; Step 4, encapsulating the conductive interfaces of the capacitive strain sensor and the bioelectrode on the flexible stretchable film substrate using conductive paste and flexible conductive tape, thereby obtaining the method for fabricating the self-encapsulated stretchable multimode sensor.

[0013] Furthermore, step 2 specifically includes: designing the strain sensor pattern and electrode pattern using computer-aided design (CAD) software; the file format applicable to the printing device is .dxf file.

[0014] Furthermore, step 3 specifically includes: importing the pattern into the printing device, adjusting the printing parameters, starting the printing device, and using 3D printing to form the pattern on the flexible stretchable film substrate using conductive silver paste and carbon paste conductive coating to obtain the printed sensor; the printing device is the Voltera V-one multi-functional desktop printing device system; the printing parameters include printing thickness, speed, ink output, and pressure value.

[0015] Furthermore, the printing parameters are specifically: printing thickness of 0.2~0.5mm, speed of 100~200mm / min, ink output of 5~10, and pressure of 0.2~0.4N.

[0016] Furthermore, between step 3 and step 4, the following step is also included: performing a qualification inspection on the printed sensor; the qualification inspection includes checking whether the substrate of the printed sensor is damaged, whether the pattern is complete, and whether the path is broken.

[0017] Further, step 1 specifically includes: selecting a flexible and stretchable material; performing ultrasonic cleaning on the flexible and stretchable material, the ultrasonic cleaning parameters including ultrasonic power 60~120W, ultrasonic frequency 40KHZ, heating power 100~300W, temperature 50~60℃, and time 10~20min; drying at 50~60℃ for 5~10min after cleaning to obtain a pretreated flexible and stretchable material; spin-coating a flexible adhesive onto the pretreated flexible and stretchable material, and obtaining the flexible and stretchable film substrate after curing.

[0018] The present invention also provides an application of the above-mentioned self-encapsulated stretchable multimode sensor in sports.

[0019] Compared with the prior art, the technical solution provided by the present invention has at least the following advantages: This invention proposes a self-encapsulated stretchable multimode sensor, its preparation method, and its application. It achieves close contact with human skin, sweat resistance, stable self-encapsulation interface without motion artifacts, and multi-layer conductive circuitry that can monitor various complex motion scenarios.

[0020] (1) Self-adhesive, stretchable conductive patterns are designed and manufactured by printing conductive patterns on a self-adhesive stretchable substrate with excellent mechanical fatigue properties.

[0021] (2) Multimode flexible motion sensing patch, which integrates array-type or interdigital electrode patterns on one or both sides of PDMS film to monitor signals such as biomuscular electrophysiology or microdeformation of human skin.

[0022] (3) Self-encapsulated film: By using conductive paste and flexible conductive tape to bond at the conductive interface, the modulus of soft-hard transition is achieved, avoiding stress concentration problems; the use of a film made of the same material as the substrate for encapsulation increases the reliability of the sensor.

[0023] (4) Digital motion application: By monitoring strain signals and electromyographic signals in real time in scenarios such as hand clenching and upper limb weightlifting, the feasibility of its practical application is verified. Attached Figure Description

[0024] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments, and unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0025] Figure 1 The flowchart below shows the fabrication process of the self-encapsulated stretchable multimode sensor of this invention. Figure 2a The circuit diagram of the capacitive strain sensor and bioelectrode in the self-encapsulated tensile multimode sensor prepared in Example 1 is shown. Figure 2b This is a physical image of a self-encapsulated stretchable multimode sensor. Figure 2c Optical microscope image of a self-encapsulated stretchable multimode sensor; Figure 3 Circuit diagrams of sensor modules with different structural types that can be used to add module levels to self-encapsulated stretchable multimode sensors; Figure 4 A diagram illustrating the application and structure of a self-encapsulated stretchable multimode sensor on the palm of the hand. Figure 5 This is a schematic diagram of a self-encapsulated stretchable multimode sensor that integrates temperature sensors, humidity sensors, and resistance sensors. Detailed Implementation

[0026] The inventors discovered that current technologies mainly use polyester and hydrogel as bases, with a single resistive strain sensor as the functional layer. These technologies cannot effectively fit the human body, have poor waterproofing, unstable interfaces, and cannot monitor complex motion behaviors.

[0027] In view of this, the purpose of this invention is to provide a self-encapsulated stretchable multimode sensor, its fabrication method, and its application method, which simplifies the fabrication process, improves fabrication efficiency and flexibility, realizes the fabrication of stretchable sensors, overcomes the limitations of unstable interfaces and one-sided data acquisition by single sensors, and meets the needs of different application scenarios.

[0028] The following detailed description, in conjunction with the accompanying drawings, illustrates a specific implementation scheme of a self-encapsulated stretchable multimode sensor, its fabrication method, and its application fabrication method, as per the present invention.

[0029] See Figure 1 In some embodiments, the fabrication of a self-encapsulated stretchable multimode sensor includes the following steps: 1. Provide stretchable substrate material The preparation of the stretchable substrate includes the following steps: selecting flexible and stretchable materials such as polydimethylsiloxane, thermoplastic polyurethane, and thermoplastic polyethylene; cleaning the flexible substrate using ultrasonic cleaning, with preferred ultrasonic cleaning conditions being an ultrasonic power of 60-120W, an ultrasonic frequency of 40kHz, a heating power of 100-300W, a temperature of 50-60℃, and a time of 10-20 minutes; drying at 50-60℃ for 5-10 minutes after cleaning; and spin-coating medical polyurethane adhesive onto the flexible substrate, followed by curing to obtain a self-adhesive stretchable film substrate.

[0030] 2. Design a stretchable sensor structure A capacitive strain sensor is selected, and the strain sensor pattern and electrode pattern are designed in CAD software to obtain the pattern required by the printing equipment and the format file compatible with it.

[0031] 3. Adjust 3D printing parameters and utilize a 3D printed stretchable sensor. First, import the preset sensor pattern into the printing device, adjust the printing parameters, and print conductive patterns such as conductive silver paste and carbon paste. Continuously adjust the printing parameters according to the printing situation to determine the optimal printing parameters: printing thickness of 0.2~0.5mm, 100~200mm / min, ink output of 5~10, and pressure of 0.2~0.4N.

[0032] 4. Inspect the conformity of self-encapsulated stretchable multimode sensors. After printing, remove the sensor and check whether the stretchable substrate is damaged and whether the sensor pattern is complete. Use a multimeter and a conductivity tester to check whether the conductive path of the sensor is continuous and complete, and whether the sensing part is complete. Finally, cut the qualified stretchable sensor to obtain the self-encapsulated stretchable multimode sensor. Example 1 See Figure 2a , Figure 2b and Figure 2c Example 1 provides a self-encapsulated stretchable multimode sensor, its fabrication method, and its application. The fabrication method specifically includes the following steps: (1) Weigh 4 g of PDMS prepolymer and 0.4 g of PDMS curing agent into a plastic cup using an electronic balance. Stir with a glass rod for 5-10 minutes to fully disperse the curing agent in the PDMS prepolymer. Then, place the mixture in a vacuum drying oven for 30 minutes (vacuum degree 0.1 MPa) to remove air bubbles and prevent uneven film formation during curing. Then, drop the degassed PDMS mixture onto a glass substrate and spin coat it using a spin coater. Set the spin coat speed to 500 r / min and the time to 30 s. Control the film thickness using centrifugal force to form a 100 μm film. Finally, place the spin-coated liquid on an 80℃ heating plate to cure for 30 minutes, allowing the PDMS to form an elastic film through crosslinking. Apply a 40-50 μm Bayer medical polyurethane adhesive layer to one side of the PDMS film. The final product is a self-adhesive, stretchable PDMS film substrate.

[0033] (2) Draw the sensor and electrode structure that meet the preset conditions in CAD software to obtain the pattern required by the printing equipment. For example... Figure 3 It is an interdigitated electrode structure with a sensor pattern size of 11×30mm and a line width of 0.5mm.

[0034] (3) Import the prepared sensor pattern into the PCB software to obtain the file format required for printing, and import the file into the printing device; place the obtained self-adhesive, stretchable PDMS film substrate facing upwards in the printing area of ​​the printing device, print the strain sensor pattern, and after curing, place the substrate facing downwards in the printing area to print the bioelectrode pattern.

[0035] (4) After printing, remove the PDMS substrate, check its qualification with a multimeter and a conductive tester, encapsulate it with PDMS material on the upper surface of the substrate, and encapsulate it with paper-based material on the lower surface of the substrate; thus obtaining a self-encapsulated stretchable multimode sensor, the structure of which is as follows: Figure 2a As shown.

[0036] Figure 2b and Figure 2c The images shown are a physical photograph and an optical microscope image of the self-encapsulated stretchable multimode sensor. Figure 3 Circuit diagrams for sensor modules with different structural types that can be used to add module levels to self-encapsulated stretchable multimode sensors. These sensor modules can be temperature sensors, humidity sensors, pull-resistance sensors, and others. Figure 4 The image in the middle left shows the self-encapsulated stretchable multimode sensor attached to the back of a human hand. Figure 4 The middle right figure shows the structure of a self-encapsulated dual-mode sensor. Figure 5 This demonstrates that the sensor can be layered with temperature sensors, humidity sensors, and resistance sensors to create a multi-mode sensor. Figure 5 It can be seen that, Figure 5 The provided self-encapsulated stretchable multimode sensor includes, from top to bottom, a bioelectrode, a capacitive sensor, a tensile-resistance sensor, a heat and humidity sensor, and a stretchable thin film substrate.

[0037] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of the present invention. Any person skilled in the art can make their own modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A self-packaged stretchable multimode sensor, characterized in that, The self-packaging stretchable multimodal sensor comprises a flexible stretchable film substrate, a capacitive strain sensor and a bioelectrode connected in sequence, the capacitive strain sensor is used for monitoring strain signals, and the bioelectrode is used for monitoring myoelectric signals; The capacitive strain sensor and the bioelectrode are integrated on the flexible stretchable film substrate by array electrode patterns or interdigital electrode patterns respectively; The conductive interfaces of the capacitive strain sensor and the bioelectrode are packaged on the flexible stretchable film substrate by conductive paste and flexible conductive adhesive tape.

2. The self-packaged stretch-bra multiple-mode sensor of claim 1, wherein, One or more of a temperature sensor, a humidity sensor and a tensile resistance sensor are further arranged between the flexible stretchable film substrate and the capacitive strain sensor.

3. The self-packaged stretchable multi-mode sensor of claim 1, wherein, The flexible stretchable film substrate is composed of a stretchable polymer film and a back adhesive film. The stretchable polymer film comprises one or more of flexible stretchable materials such as polydimethylsiloxane, thermoplastic polyurethane and thermoplastic polyethylene. The back adhesive film comprises one or more of flexible adhesives such as medical acrylic pressure-sensitive adhesive, silicone pressure-sensitive adhesive, hydrocolloid adhesive, polyurethane-based adhesive and hot melt adhesive. The back adhesive film is used to realize the self-adhesion of the self-packaging stretchable multimodal sensor.

4. A method of manufacturing a self-packaged stretchable multimode sensor according to any one of claims 1 to 3, characterized in that, The method comprises the following steps: Step 1, preparing a flexible stretchable film substrate; Step 2, designing a strain sensor pattern of the capacitive strain sensor and an electrode pattern of the bioelectrode respectively, obtaining a pattern required by a printing device and exporting the pattern into a file format suitable for the printing device; Step 3, importing the pattern into the printing device, and performing 3D printing on the flexible stretchable film substrate by using conductive silver paste and carbon paste to obtain a printed sensor; Step 4, packaging the conductive interfaces of the capacitive strain sensor and the bioelectrode on the flexible stretchable film substrate by using conductive paste and flexible conductive adhesive tape to obtain a preparation method of the self-packaging stretchable multimodal sensor.

5. The method of claim 4, wherein the self-packaged stretchable multimode sensor is prepared by, Step 2 specifically comprises: designing the strain sensor pattern and the electrode pattern by using computer-aided design software; The file format suitable for the printing device is a.dxf file.

6. The method of claim 4, wherein the self-packaged stretchable multimode sensor is prepared by, Step 3 specifically comprises: importing the pattern into the printing device, adjusting printing parameters, starting the printing device, and using 3D printing to form the pattern on the flexible stretchable film substrate by using conductive silver paste and carbon paste as conductive coating to obtain the printed sensor; The printing device is a Voltera V-one multifunctional desktop printing device, and the printing parameters include printing thickness, speed, ink output and pressure value.

7. The method of claim 6, wherein the self-packaged stretch- type multimode sensor is prepared by the steps of: The printing parameters are specifically: the printing thickness is 0.2-0.5 mm, the speed is 100-200 mm / min, the ink output is 5-10, and the pressure value is 0.2-0.4 N.

8. The method of claim 4, wherein the self-packaged stretchable multimode sensor is prepared by, Between step 3 and step 4, there is also a step of performing qualification inspection on the printed sensor. The qualification inspection includes checking whether the substrate of the printed sensor is damaged, whether the pattern is complete, and whether the path is open circuit.

9. The method of claim 4, wherein the self-packaged stretchable multimode sensor is prepared by, The step 1 specifically comprises: selecting a flexible stretchable material; ultrasonic cleaning the flexible stretchable material, the parameters of the ultrasonic cleaning comprising an ultrasonic power of 60-120 W, an ultrasonic frequency of 40 KHZ, a heating power of 100-300 W, a temperature of 50-60 DEG C, and a time of 10-20 min; drying at 50-60 DEG C after cleaning for 5-10 min to obtain a pretreated flexible stretchable material; spin coating a flexible glue on the pretreated flexible stretchable material to obtain the flexible stretchable film substrate after curing.

10. Use of a self-packaged stretchable multimode sensor according to any one of claims 1 to 3 in sports.

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