MXene-based patterned flexible temperature sensor and data acquisition method thereof

Abstract

The invention relates to the technical field of flexible electronics, in particular to an MXene-based patterned flexible temperature sensor and a data acquisition method thereof, and the method comprises the following steps: S1, synthesizing an MXene group: carrying out the reaction synthesis of concentrated hydrochloric acid and Ti3AlC2 through a hydrofluoric acid etching method to obtain an MXene suspension; s2, carrying out patterning design, and simulating COMSOLMultiphysics by using a finite element, so as to obtain flexible temperature sensors after different patterning improvements; after MXene turbid liquid is synthesized from Ti3AlC2 through a hydrofluoric acid selective etching method, a basic sensor pattern is simulated and optimized by using a finite element based on COMSOL Multiphysics, and the temperature resolution and the response speed are improved; carrying out packaging and curing after silk-screen printing; the flexible temperature sensor is connected with the multi-channel acquisition system through an electrode lead, temperature signals are processed through signal amplification, filtering and A / D conversion, and data are wirelessly transmitted in combination with the Bluetooth module. The method is suitable for curved surface temperature field monitoring of wearable medical and industrial equipment.

Description

Technical Field

[0001] The present invention relates to the field of flexible electronic detection, and in particular to a MXene-based patterned flexible temperature sensor and a data acquisition method thereof. Background Art

[0002] As traditional temperature measurement components, temperature sensors play a vital role in numerous fields, such as fault alarms for industrial production equipment, human temperature monitoring in the medical field, and temperature control in today's smart homes. However, traditional temperature measurement methods have limited their application. There is a growing demand for diverse and high-performance temperature monitoring technologies in today's society. Traditional rigid temperature sensors are typically large in size, rigid in structure, have low sensitivity, and have long response times. These shortcomings make them inadequate for applications such as temperature measurement of complex curved surfaces, multi-point distributed temperature monitoring, and real-time tracking of rapidly changing temperature fields.

[0003] Furthermore, most flexible temperature sensors have complex data collection systems that rely on traditional wired connections. These systems are complex, costly, and inflexible, limiting their flexibility, convenience, and performance in practical applications.

[0004] Qin et al. studied advanced patterning technology to manufacture flexible sensors and discussed several key patterned micro-nanostructure manufacturing technologies, including printing technology, photolithography technology, soft lithography technology, mold method, nanoimprint lithography technology and laser direct writing technology; the study pointed out that patterning technology can significantly improve key performance indicators such as sensor sensitivity, resolution, and response speed.

[0005] Patent CN202510109380.0 describes a resistive flexible temperature sensor device that uses graphene as a conductive ink and screen-prints it. This invention has the disadvantage of using graphene as a temperature-sensitive material, which has poor chemical stability.

[0006] Patent CN202510131267.2 provides a method for preparing a temperature sensor using a thermosensitive composite material applied to a flexible cashmere fiber substrate. After synthesizing a MXene dispersion, the thermosensitive composite material is applied to a flexible cashmere substrate using an impregnation method. Curing and encapsulation are then performed to produce a thermosensitive composite temperature sensor. However, this invention has the disadvantage of only having a single pattern and cannot meet diverse temperature measurement needs.

[0007] MXene is a new type of two-dimensional transition metal carbide, nitride, or carbonitride with unique physical and chemical properties. It has high electrical conductivity, a large specific surface area, and a rich array of surface chemical functional groups. As temperature changes, its electrical conductivity remains stable while its thermal conductivity increases. It is sensitive to temperature changes, enabling high signal-to-noise ratio and high-precision temperature sensing while avoiding damage to devices caused by internal heat accumulation at high temperatures. Furthermore, the design of flexible temperature sensors with different patterns gives it a unique advantage as a sensitive material for flexible temperature sensors.

[0008] Existing research focuses on the preparation and performance of single MXene-based flexible temperature sensors, while relatively little research has been conducted on MXene-based patterned flexible temperature sensors and their associated data acquisition methods. However, achieving high-precision, distributed measurement and real-time monitoring of surface temperature requires not only high-performance flexible temperature sensors but also a stable, reliable, convenient, and fast data acquisition method to efficiently collect, process, and transmit multiple sensor signals. This method also requires excellent stability and anti-interference capabilities to ensure the accuracy and reliability of the collected data. Furthermore, it can facilitate data communication with host computers, mobile terminals, and other devices, enabling remote monitoring and data analysis to meet data management needs in various application scenarios. Summary of the Invention

[0009] (1) Technical problems solved

[0010] The purpose of the present invention is to provide a MXene-based patterned flexible temperature sensor and a data acquisition method thereof, which can adapt to a certain degree of bending and stretching, and perform real-time data collection on the collected signals, thereby improving the sensitivity and stability of the flexible temperature sensor; and solving the problems raised in the above-mentioned background technology.

[0011] (2) Technical solution

[0012] To achieve the above objectives, the present invention adopts the following scheme:

[0013] A method for fabricating a MXene-based patterned flexible temperature sensor comprises the following steps:

[0014] S1. Synthesis of MXene-based: MXene suspension was synthesized by the hydrofluoric acid etching method using concentrated hydrochloric acid and Ti3AlC2;

[0015] S2. Pattern design: Using finite element simulation COMSOL Multiphysics, we can obtain flexible temperature sensors with different pattern improvements.

[0016] S3. Screen printing and packaging of flexible temperature sensors. MXene suspension is applied using screen printing and then encapsulated using PDMS.

[0017] Furthermore, the synthesis of the MXene base in S1 includes: using a hydrofluoric acid etching method, using 25 ml of concentrated hydrochloric acid to react with a fluoride salt to obtain hydrofluoric acid, weighing 1.5 g of Ti3AlC2 as a raw material, reacting it with hydrofluoric acid, and using the selective etching effect of hydrofluoric acid to remove the aluminum in Ti3AlC2, thereby obtaining MXene; subsequently, using centrifugal separation and repeated washing to remove by-products generated during the reaction until the washed solution reaches neutrality; finally, dispersing the obtained MXene product in deionized water and performing ultrasonic treatment to form a uniform and stable MXene suspension.

[0018] Furthermore, the patterning design in S2 also includes: creating a three-dimensional model in the finite element simulation COMSOL Multiphysics according to the performance of the basic sensor to clarify the structural layout of the sensitive layer; setting the MXene material parameters, conductivity, dielectric constant, and thermal conductivity; establishing current field and temperature field to simulate the influence of different pattern shapes, circular, square, and regular hexagonal flexible basic sensors on temperature distribution, and analyzing their sensitivity to temperature response through changes in their resistance; and determining the optimal patterning scheme by optimizing the pattern size and spacing to improve the temperature resolution and response speed of the basic sensor.

[0019] Furthermore, the screen printing and packaging of the flexible temperature sensor in S3 includes: using an aluminum substrate as an operating platform, using a 300-mesh screen printing screen and brushing with a screen printing screen with a specific pattern, the specific pattern is square, hexagonal and circular, first, printing interdigitated silver electrodes and electrode leads on the PDMS substrate, then brushing the synthesized MXene suspension, and curing it in an oven at 120°C for 30 minutes, and finally encapsulating it with PDMS.

[0020] A data acquisition method for a MXene-based patterned flexible temperature sensor, comprising:

[0021] S4. Circuit design and data collection: The flexible temperature sensor is connected to the integrated system circuit through electrode leads; a Bluetooth module is selected to realize wireless data transmission and reception.

[0022] Furthermore, the circuit design and data collection in S4 include: connecting the flexible temperature sensor prepared in S3 with the system circuit using electrode leads; connecting the system circuit with the mobile application via a Bluetooth module;

[0023] The system circuit includes a power module, a data processing module and a Bluetooth module;

[0024] The power module provides power for the data processing module and the Bluetooth module;

[0025] The data processing module first amplifies the signal, filters the amplified signal to reduce noise interference, and then performs A / D conversion to convert the amplified and filtered analog signal into a digital signal to facilitate subsequent data processing;

[0026] The Bluetooth module can transmit real-time temperature data to mobile applications.

[0027] (3) Beneficial effects

[0028] Compared with the prior art, the present invention provides a MXene-based patterned flexible temperature sensor and a data acquisition method thereof, which has the following beneficial effects:

[0029] The flexible temperature sensor material of the present invention is MXene, which has a unique two-dimensional nanostructure and excellent electrical properties, enabling the flexible temperature sensor to respond quickly to temperature changes. Its electrical conductivity changes significantly with temperature changes, and it can detect tiny temperature changes, thereby generating detectable electrical signal changes, achieving highly sensitive temperature detection.

[0030] The present invention uses finite element simulation to design different patterns, which can not only simulate temperature heating to explore the change of resistance with temperature, but also explore the sensitivity of different patterns to temperature, reflecting the sensitivity of flexible temperature sensors with different patterns.

[0031] The present invention collects and transmits data in real time by adopting a system circuit design, which can accurately convert the weak analog signal output by the sensor into a digital signal, ensuring the integrity and accuracy of the data; at the same time, through the filtering circuit, it can effectively remove noise interference, improve the signal-to-noise ratio, and make the collected data clearer and more reliable; using Bluetooth for wireless transmission not only eliminates the physical connection limitations of traditional wired sensors, avoids cable breakage or poor contact due to mechanical deformation, and improves system reliability; it also has a low latency to meet the needs of real-time temperature measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Flow chart for preparing the MXene suspension provided by the present invention;

[0033] Figure 2 This is a structural diagram of the square pattern sensor provided by the present invention;

[0034] Figure 3 The resistance change rate versus temperature graph of the finite element simulation COMSOL Multiphysics provided by the present invention;

[0035] Figure 4 A flow chart of the system circuit provided by the present invention;

[0036] Figure 5 This is a simulation diagram of flexible temperature sensors with different patterns using COMSOL Multiphysics finite element simulation provided by the present invention. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0038] Example 1

[0039] Due to its excellent flexibility, the present invention can be tightly attached to objects with complex curved surfaces such as human skin and robot grippers, greatly expanding the applicable scenarios of temperature measurement and providing an accurate and reliable temperature monitoring method for biomedicine, smart wearable devices, and other fields.

[0040] like Figure 1-5 As shown, the present invention provides a method for manufacturing a MXene-based patterned flexible temperature sensor, which mainly includes the following steps: MXene-based synthesis, pattern design, screen printing and packaging of the flexible temperature sensor, circuit design and data collection.

[0041] S1. Synthesis of MXene: A MXene suspension is obtained by hydrofluoric acid etching. 25 ml of concentrated hydrochloric acid is measured using a graduated cylinder and placed in the core of a large reactor, which is then placed in an ice bath. 1.5 g of lithium fluoride is weighed on paper and quickly added to the concentrated hydrochloric acid. The reactor is sealed and stirred in an ice bath for 30 minutes. 0.5 g of Ti3AlC2 is slowly added to the reactor, which is sealed with tape and stirred in an oil bath for 48 hours. After the 48-hour oil bath, the mixture is transferred to a centrifuge tube and sonicated in an ice bath for 1 hour. Following a preliminary centrifugation (12,000 rpm for 20 minutes), the supernatant is decanted, the remaining layer is poured into 30 ml of water, and the above steps are repeated until the pH approaches 7. A final centrifugation is performed at 1200 rpm for 5 minutes, retaining the upper layer. This procedure yields a MXene suspension for subsequent screen printing.

[0042] S2. Patterned design: This step uses COMSOL Multiphysics, a finite element simulation tool, to perform patterned design of the sensor. Three different patterned flexible temperature sensor models (circular, square, and regular hexagonal) are constructed in COMSOL Multiphysics. After setting the material parameters, convection heat transfer boundary conditions are applied to the outer boundaries of the model to simulate the heat exchange between the flexible temperature sensor and the surrounding environment. The ambient temperature is set to 25°C. A temperature load is applied to the upper surface of the sensor to simulate the heating effect of the measured object on the flexible temperature sensor. The temperature range is from 25°C to 95°C to simulate different working scenarios. The model is meshed using free meshing. A solver is selected for finite element solution to obtain the steady-state temperature distribution and electric field distribution of the sensor at different temperatures. The temperature and resistance values ​​of the MXene sensor are extracted through parametric sweeping.

[0043] S3. Screen printing and packaging of flexible temperature sensors: After fixing the patterned screen printing screen on the operating platform, first place a 300μm thick PDMS substrate under the screen printing screen to brush the interdigitated silver electrodes. After brushing, brush silver on both sides of the interdigitated electrodes to connect them to the electrode leads; then pour the MXene suspension into one end of the screen printing template on the PDMS substrate with the interdigitated silver electrodes and electrode leads, and scrape the scraper along the surface of the template to squeeze the ink through the mesh holes onto the substrate to form the designed pattern.

[0044] After screen printing, the flexible substrate printed with the MXene pattern is placed in an oven for drying at 120°C. Finally, the sensor surface is brought into contact with the PDMS on an operating platform, and then a lightweight pressing plate is used to apply pressure to evenly press the PDMS onto the sensor surface to complete the encapsulation.

[0045] S4. Circuit Design and Data Collection: The MXene-based flexible temperature sensor prepared in S3 is connected to the system circuit via electrode leads, and the mobile application is wirelessly connected to the system circuit. The MXene-based flexible temperature sensor in S3 is used to collect temperature signals and transmit them to the system circuit via the electrode leads. The system circuit processes the temperature signals to obtain body temperature data, which is then transmitted wirelessly to the mobile application.

[0046] Specifically, the system circuit module includes: a power module, a data processing module, and a Bluetooth module. The power module of the system circuit is used to provide power to the data processing module and the Bluetooth module. The data processing module is used to process data, wherein the amplifier circuit amplifies the weak signal output by the MXene-based flexible temperature sensor. The positive and negative input terminals of the operational amplifier are respectively connected to the output terminals of the sensor to ensure stable signal amplification; the filter circuit is used to filter out high-frequency interference signals from the temperature signal to ensure data accuracy during A / D conversion; the A / D conversion circuit is used to convert the analog electrical signal output by the sensor into a digital signal to obtain body temperature data, and transmit the body temperature data to the Bluetooth module. The Bluetooth module is used to wirelessly transmit the body temperature data to the mobile application.

[0047] Because the MXene-based flexible temperature sensor is a resistive temperature sensor, a voltage divider circuit is used to read the temperature signal as a voltage. After amplification, filtering, and A / D conversion, the temperature data is obtained. This temperature data is then transmitted to a Bluetooth module, which wirelessly transmits the temperature data to a mobile application.

[0048] In order to better illustrate the design of the MXene-based flexible temperature sensor with different patterns, three specific examples of MXene-based flexible temperature sensors with different patterns are provided below.

[0049] Example 2

[0050] like Figure 5 As shown in the figure, a MXene-based flexible temperature sensor was patterned using COMSOL Multiphysics finite element simulation. A circular MXene-based flexible temperature sensor model with a diameter of 9 mm was constructed in COMSOL Multiphysics. After setting the material parameters, a convection heat transfer boundary condition was applied to the outer boundary of the model to simulate heat exchange between the flexible temperature sensor and the surrounding environment. The ambient temperature was set to 25°C. A temperature load was applied to the upper surface of the flexible temperature sensor to simulate the heating effect of the measured object on the flexible temperature sensor. The temperature range was from 25°C to 95°C to simulate different operating scenarios. The model was meshed using the free meshing method. A finite element solver was selected for the finite element solution to obtain the steady-state temperature and electric field distribution of the flexible temperature sensor at different temperatures. The temperature and resistance values ​​of the MXene sensor were extracted using a parametric sweep.

[0051] Example 3

[0052] like Figure 5As shown in the figure, a MXene-based flexible temperature sensor was patterned using COMSOL Multiphysics finite element simulation. A 16mm square MXene-based flexible temperature sensor model was constructed in COMSOL Multiphysics. After setting material parameters, convection heat transfer boundary conditions were applied to the model's outer boundaries to simulate heat exchange between the flexible temperature sensor and the surrounding environment. The ambient temperature was set to 25°C. A temperature load was applied to the top surface of the flexible temperature sensor to simulate the heating effect of the measured object on the flexible temperature sensor. The temperature range was from 25°C to 95°C to simulate different operating scenarios. The model was meshed using the free meshing method. A finite element solver was selected for the finite element method to obtain the steady-state temperature and electric field distribution of the flexible temperature sensor at different temperatures. The temperature and resistance values ​​of the MXene-based flexible temperature sensor were extracted using a parametric sweep.

[0053] Example 4

[0054] like Figure 5 As shown in the figure, a MXene-based flexible temperature sensor was patterned using COMSOL Multiphysics finite element simulation. A MXene-based patterned flexible temperature sensor model with a hexagonal side length of 10 mm was constructed in COMSOL Multiphysics. After setting material parameters, a convection heat transfer boundary condition was applied to the outer boundary of the model to simulate heat exchange between the flexible temperature sensor and the surrounding environment. The ambient temperature was set to 25°C. A temperature load was applied to the top surface of the flexible temperature sensor to simulate the heating effect of the measured object on the flexible temperature sensor. The temperature range was from 25°C to 95°C to simulate different operating scenarios. The model was meshed using the free meshing method. A finite element solver was selected for the calculation, and the steady-state temperature and electric field distribution of the flexible temperature sensor at different temperatures were obtained. The temperature and resistance values ​​of the MXene-based flexible temperature sensor were extracted using a parametric sweep.

[0055] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for fabricating a MXene-based patterned flexible temperature sensor, characterized in that: The following steps are involved: S1. Synthesis of MXene-based: MXene suspension was synthesized by the hydrofluoric acid etching method using concentrated hydrochloric acid and Ti3AlC2; S2. Pattern design: Using finite element simulation COMSOL Multiphysics, we can obtain flexible temperature sensors with different pattern improvements. S3. Screen printing and packaging of flexible temperature sensors. MXene suspension is applied using screen printing and then encapsulated using PDMS.

2. The method for fabricating a MXene-based patterned flexible temperature sensor according to claim 1, wherein: The synthesis of the MXene base in S1 includes: using a hydrofluoric acid etching method, using 25 ml of concentrated hydrochloric acid to react with a fluoride salt to obtain hydrofluoric acid, weighing 1.5 g of Ti3AlC2 as a raw material, reacting it with hydrofluoric acid, and using the selective etching effect of hydrofluoric acid to remove aluminum in Ti3AlC2, thereby obtaining MXene; subsequently, using centrifugal separation and repeated washing to remove by-products generated during the reaction until the washed solution reaches neutrality; finally, dispersing the obtained MXene product in deionized water and performing ultrasonic treatment to form a uniform and stable MXene suspension.

3. The method for fabricating a MXene-based patterned flexible temperature sensor according to claim 1, wherein: The pattern design in S2 also includes: creating a three-dimensional model based on the performance of the basic sensor in the finite element simulation COMSOL Multiphysics to clarify the structural layout of the sensitive layer; setting the MXene material parameters, conductivity, dielectric constant, and thermal conductivity; establishing current fields and temperature fields to simulate the influence of different pattern shapes, circular, square, and regular hexagonal flexible basic sensors on temperature distribution, and analyzing their sensitivity to temperature response through changes in their resistance; and determining the optimal patterning scheme by optimizing the pattern size and spacing to improve the temperature resolution and response speed of the basic sensor.

4. The method for fabricating a MXene-based patterned flexible temperature sensor according to claim 1, wherein: The screen printing and packaging of the flexible temperature sensor in S3 includes: using an aluminum substrate as an operating platform, using a 300-mesh screen printing screen and brushing with a screen printing screen with a specific pattern, the specific pattern is square, hexagonal and circular, first, printing interdigitated silver electrodes and electrode leads on the PDMS substrate, then brushing the synthesized MXene suspension, and curing it in an oven at 120°C for 30 minutes, and finally encapsulating it with PDMS.

5. A data acquisition method for a MXene-based patterned flexible temperature sensor, characterized in that: include: S4, circuit design and data collection, the flexible temperature sensor is connected to the integrated system circuit through the electrode lead; Select Bluetooth module to realize wireless data transmission and reception; A sensor manufactured using the method for manufacturing a MXene-based patterned flexible temperature sensor according to any one of claims 1 to 4 is used.

6. The data acquisition method for a MXene-based patterned flexible temperature sensor according to claim 5, characterized in that: The circuit design and data collection in S4 include: connecting the flexible temperature sensor prepared in S3 to the system circuit using electrode leads; connecting the system circuit to the mobile application via a Bluetooth module; The system circuit includes a power module, a data processing module and a Bluetooth module; The power module provides power for the data processing module and the Bluetooth module; The data processing module first amplifies the signal, filters the amplified signal to reduce noise interference, and then performs A / D conversion to convert the amplified and filtered analog signal into a digital signal to facilitate subsequent data processing; The Bluetooth module can transmit real-time temperature data to mobile applications.

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