High-compressibility and oxidation-resistant titanium carbide flexible pressure sensor, and fabrication and application thereof

Abstract

The present invention belongs to the technical field of flexible sensing devices. Disclosed are a high-compressibility and oxidation-resistant titanium carbide flexible pressure sensor, and the fabrication and application thereof. Large-sized and wrinkled Ti3C2(TS) is first constructed by S-bonding Ti3C2 nanosheets and formulated into TS ink, and a microelectronic printing technique is then used to fabricate an Ag / TS / Ag flexible pressure sensor. The introduction of a TS microstructure increases the compression space and deformation capability of a sensing layer, and enhances the variation of contact sites, thereby improving the device sensitivity. A TS flexible pressure sensor has a sensitivity of 7.8 kPa-1, which is approximately five times that of a Ti3C2 flexible pressure sensor, exhibits a short device response time (50 ms) and an ultra-low detection limit of only 0.2 Pa, and enables stable cycling, demonstrating excellent performance. Moreover, on the basis of S-ion edge capping, the device is less prone to oxidation, resulting in enhanced stability. By applying the sensor to wireless sleep respiration monitoring, the accurate monitoring of different breathing states can be realized.

Description

High compression, oxidation-resistant titanium carbide flexible pressure sensor and preparation and application thereof TECHNICAL FIELD

[0001] The present application relates to the technical field of flexible sensing devices, in particular to a high compression, oxidation-resistant titanium carbide flexible pressure sensor and preparation and application thereof. BACKGROUND

[0002] Flexible pressure sensors have great application potential in the field of intelligent medical care due to their excellent flexibility, sensitivity and adaptability. In medical monitoring, it is crucial to improve the accuracy of capturing and monitoring small signals. Flexible pressure sensors can accurately detect physiological signals of patients such as heartbeat, respiration and blood pressure, and the measured data can be used as a reference for hospitals to develop treatment plans. In addition, flexible pressure sensors can also be used to make intelligent wearable devices to monitor the physiological state of patients in real time and provide personalized health management solutions. Therefore, it is extremely important to construct a flexible pressure sensor with high sensitivity, long-term stability, comfort and convenience for monitoring small physiological signals.

[0003] Ti3C2 MXene material is a two-dimensional transition metal carbide or nitride with excellent electrical conductivity and flexibility. Combining Ti3C2 material with flexible materials or elastic substrates will help further improve the compression performance of the material, and such materials have become one of the ideal materials for constructing flexible pressure sensors. However, at present, such materials are still difficult to be used as independent piezoresistive materials, which is mainly due to the limitation of the limited interlayer spacing and compression space of traditional Ti3C2 materials. It is known to those skilled in the art that the introduction of microstructure is expected to increase the contact site and area change of the material under pressure, increase the relative resistance change, and is one of the effective strategies to improve the sensitivity of the sensor.

[0004] In this regard, Chinese patent CN 109887758 A discloses an ultra-large size titanium carbide nanosheet with a wrinkle structure, which is prepared by hydrothermal reaction of ultra-thin Ti3C2 nanosheet and Na2S·9H2O. Since the prepared titanium carbide nanosheet has a wrinkle structure, the specific surface area of the material is significantly increased, and the migration channel of electrolyte ions is increased. Therefore, the patent further studies the application of the material as a flexible electrode in electrochemical energy storage. At present, no related technical personnel have successfully applied this morphology of titanium carbide to the sensor field. Although the introduction of Ti3C2 with large size and wrinkle microstructure is theoretically expected to improve the contact site change under pressure and thus help improve the sensitivity of the sensor. However, the specific preparation scheme of the sensor based on this material cannot be determined, and different sensor preparation schemes will affect the final performance of the sensing material.

[0005] In addition, Ti3C2 material is easy to be oxidized in air, resulting in its electromechanical performance being damaged, which limits the stability of its device. Ti3C2 exposes a large number of metastable metal atoms on the surface, so that it has a high surface energy and thermodynamic instability. Water molecules and dissolved oxygen are the key factors leading to the oxidation of Ti3C2 material. The oxidation process often starts from the defect or edge part of the Ti3C2 nanosheet and spreads rapidly to other areas. The degree of oxidation is closely related to the size and the density of surface defects, wherein the Ti3C2 nanosheet with smaller size and more defects is more susceptible to oxidation. At present, the methods for improving the stability of Ti3C2 mainly include adjusting the storage conditions, forming a protective barrier on the surface or edge, and optimizing the preparation conditions and post-treatment modification, but the existing schemes generally have the problems of high operation difficulty, high technical requirements and influence on the performance of the material itself. Therefore, while introducing the microstructure to improve the sensitivity of the device, it is also necessary to consider whether the introduction of the corresponding structure will affect the stability of the material.

[0006] SUMMARY

[0007] The present application aims to solve the problems in the prior art, and provides a high-compression and oxidation-resistant titanium carbide flexible pressure sensor and discloses a preparation method thereof. Specifically, a large-size and wrinkled TS is used as a sensing material, and a flexible pressure sensor with high sensitivity and long-term stability of Ag / TS / Ag sandwich structure is constructed by microelectronic printing technology. The introduction of the microstructure solves the problem of limited interlayer spacing and compression space of Ti3C2 intrinsic material, and the covering of the oxidation site based on S ion edge termination can reduce oxidation and significantly improve the stability of the material.

[0008] In order to realize the above technical purpose, the present application is realized by the following technical scheme: a preparation method of a high-compression and oxidation-resistant titanium carbide flexible pressure sensor, comprising the following steps:

[0009] 1) A multilayer Ti3C2 is prepared by wet etching Ti3AlC2, and ultrasonic peeling is performed to obtain an ultrathin Ti3C2 nanosheet;

[0010] 2) The ultrathin Ti3C2 nanosheet is mixed with Na2S·9H2O to perform a hydrothermal reaction, and a large-size and wrinkled Ti3C2 sheet is constructed, which is denoted as TS;

[0011] 3) The TS is dispersed in a dimethyl sulfoxide solution, mixed and centrifuged, and the precipitate is reserved to obtain a TS printing ink;

[0012] 4) On a microelectronic printing equipment platform, Ag electrodes are printed on a flexible substrate using conductive silver paste. The Ag electrodes are dried, and a sensing layer is printed on the Ag electrodes using TS printing ink. Then, another Ag electrode is printed on one side of the sensing layer. The flexible substrate is peeled off to obtain a flexible pressure sensor with an Ag / TS / Ag sandwich structure.

[0013] Furthermore, in step 2), the molar ratio of ultrathin Ti3C2 nanosheets to Na2S·9H2O is 1:5 to 240, the hydrothermal reaction temperature is 25℃ to 240℃, and the reaction time is 12 to 24h.

[0014] Furthermore, in step 4), a 25G needle with an inner diameter of 0.26 mm is used for printing, and the printing speed is 2–4 mm / s. -1 The printing air pressure is 5-25 kPa.

[0015] Furthermore, in step 4), the printing area of ​​the Ag electrode is 10 mm². 2 ~500mm 2 The thickness of the Ag electrode is not less than 40 μm, and the thickness of the sensing layer is 8–28 μm.

[0016] Preferably, the thickness of the sensing layer is 15 μm.

[0017] The highly compressible, oxidation-resistant titanium carbide flexible pressure sensor prepared using the above method achieves a sensitivity of 7.8 kPa. -1 It has a response time of 50ms under an applied pressure of 0.25kPa, a minimum detection limit of 0.2Pa, and can stably cycle more than 10,000 times under loading and unloading conditions of 0.5kPa pressure.

[0018] The beneficial effects of this invention are as follows:

[0019] 1. The high-compression, oxidation-resistant titanium carbide flexible pressure sensor disclosed in this application utilizes large-size, wrinkled TS as the sensing layer material and is constructed using microelectronic printing technology to create an Ag / TS / Ag sandwich structure sensor. The special structure of TS can effectively improve the problem of limited compression space of traditional Ti3C2 materials. Furthermore, based on the characteristic of S ion edge-capping covering easily oxidized sites, the liquid-phase and solid-phase stability of TS materials is significantly improved compared to traditional ultrathin Ti3C2 materials, which can reduce the oxidation phenomenon of materials. Therefore, without other treatments, the electromechanical performance of the sensor prepared based on TS is well maintained, and the service life can also be significantly improved. This can effectively broaden the application scenarios of this type of material and provide possibilities for its further promotion and application.

[0020] 2、The application uses TS as the sensing layer material of the flexible pressure sensor, the introduction of large size and wrinkle microstructure improves the contact site change under pressure, which helps to improve the sensitivity of the sensor, the sensitivity (7.8 kPa -1 ) of the TS flexible pressure sensor is about 5 times that (1.7 kPa -1 ) of the Ti3C2 flexible pressure sensor, and the corresponding characteristics make it possible to use Ti3C2 material as an independent piezoresistive material to construct a high-sensitivity and long-stability flexible pressure sensor;

[0021] 3、The response time of the sandwich structure flexible pressure sensor constructed by using TS as the sensing layer material of the flexible pressure sensor is 50 ms, the minimum detection limit reaches 0.2 Pa, the performance is excellent, and the stability is excellent and can be stably cycled more than 10,000 times;

[0022] 4、The flexible pressure sensor is constructed by using microelectronic printing process, which can be compatible with various functional printing materials (Ag electrode and TS sensing layer), and can manufacture sensors of different sizes from micro to macro, and realize the patterning and manufacturing of the sensor quickly;

[0023] 5、The wireless sleep breathing monitoring system constructed by the application verifies the feasibility of the flexible pressure sensor in accurately monitoring the small respiratory signal, and has great application potential in the fields of intelligent medical treatment, health monitoring and human-computer interaction;

[0024] 6、The preparation process of the titanium carbide flexible pressure sensor disclosed by the application is simple, the preparation cost is low, and it is expected to become a feasible choice for future low-cost and functional sensor applications, and also provides a new idea for the development of the corresponding field. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1a is a schematic diagram of the preparation process of large-size and wrinkle Ti3C2 sheet (TS), and b is a transmission electron microscope (TEM) picture of the obtained TS;

[0026] Figure 2 is a SEM cross-sectional view of Ti3C2 film (a) and TS film (b) under the same mass condition;

[0027] Figure 3 is an optical stability photo of Ti3C2 solution and TS solution under different storage conditions;

[0028] Figure 4 is an optical stability photo of Ti3C2 film and TS film under different storage conditions;

[0029] Figure 5 is a schematic diagram of constructing a sandwich structure Ag / TS / Ag flexible pressure sensor by using microelectronic printing technology;

[0030] Figure 6a is a detached Ag electrode from the flexible substrate, and b is a detached Ag electrode / TS sensing layer freestanding film from the flexible substrate;

[0031] Figure 7 is the response time and recovery time of the TS flexible pressure sensor;

[0032] Figure 8a is a minimum detection limit test diagram of the TS flexible pressure sensor, and b is a photo of detecting sesame on the sensor;

[0033] Figure 9 is a stability diagram of the TS flexible pressure sensor after more than 10000 cycles;

[0034] Figure 10 is a comparison diagram of the sensitivity of the Ti3C2 flexible pressure sensor and the TS flexible pressure sensor;

[0035] Figure 11 is a schematic diagram of the system structure of the wireless sleep respiratory monitoring system. DETAILED DESCRIPTION

[0036] The following examples further illustrate the content of the present application, but should not be construed as limiting the present application. Modifications and replacements of the method, steps or conditions of the present application, without departing from the essence of the present application, all belong to the scope of the present application.

[0037] Example 1

[0038] Step one, preparation of high compression and antioxidant TS material.

[0039] (1) Ti3AlC2 was etched by wet etching, LiF / HCl was used as etchant, and multilayer Ti3C2 was obtained by etching.

[0040] (2) After ultrasonic exfoliation of the multilayer Ti3C2, ultrathin Ti3C2 nanosheets with a lateral size mainly distributed in 500 nm were obtained. The ultrathin Ti3C2 nanosheets were added to deoxidized water and stirred uniformly for use. The preparation of ultrathin Ti3C2 nanosheets is prior art, which is not described in detail here.

[0041] (3) Na2S·9H2O was added to ultrapure water under Ar atmosphere and stirred until completely dissolved. Then the ultrathin Ti3C2 nanosolution prepared in step (2) was added, and stirred under Ar atmosphere until mixed uniformly (the molar ratio of Ti3C2 nanosheet to Na2S·9H2O was 1:80). The mixture was placed in a reaction kettle and heated to 180℃ for hydrothermal reaction, and the reaction time was 24h.

[0042] (4) The product of the above step was centrifuged at 10000 rpm for 15 min, and washed with deionized water for 6 times. The precipitate was collected to obtain large-size and wrinkled Ti3C2 sheet, which was denoted as TS.

[0043] (5) Morphology characterization was performed using TEM to observe the size of TS sheets under different reaction conditions (see Fig. 1, panel b), and the maximum transverse size was 7 μm.

[0044] (6) The TS was uniformly ultrasonically dispersed, and a TS film was prepared by a vacuum-assisted filtration method and dried at room temperature for 24 h.

[0045] As a comparison, the ultrathin Ti3C2 nanosheets prepared in step (2) were also uniformly ultrasonically dispersed, and a film of the same mass of the ultrathin Ti3C2 nanosheets was prepared by a vacuum-assisted filtration method. The cross-sectional images of the two films were observed by SEM (see Fig. 2). As can be seen from Fig. 2, panel b, the thickness of the TS film was ~ 6 μm, and the thickness of the film of the conventional ultrathin Ti3C2 nanosheets (Fig. 2, panel a) was ~ 3 μm. The thickness of the TS film was about twice that of the film of the ultrathin Ti3C2 nanosheets, indicating that the introduction of the large size and wrinkle microstructure improved the compression space and improved the problem of limited interlayer spacing of the conventional Ti3C2 material.

[0046] The Ti3C2 and TS aqueous solutions with a concentration of 10 mg mL -1 The Ti3C2 and TS aqueous solutions with a concentration of 10 mg mL

[0047] The Ti3C2 and TS films were placed in an air environment, and the integrity and flexibility of the films were observed to directly judge the oxidation state of the films. In the initial state, the films had good flexibility, and as the oxidation phenomenon occurred, the films gradually cracked and lost flexibility. Tensile property tests were performed by a universal testing machine to characterize the mechanical stability, and a four-probe tester was used to test the electrical stability. As can be seen from Fig. 4, the Ti3C2 film in the air environment could only be stably stored for 14 days, while the TS film could be stably stored for 49 days. The solid-phase stability of the TS film was higher.

[0048] The TS material had higher liquid-phase stability and solid-phase stability than the intrinsic Ti3C2 nanosheets. The reason for the difference was that the S ion edge passivation effect existed in the TS material, which helped to delay the oxidation of the material, maintain the performance of the material, broaden the application scenarios of the material, and prolong the service life of the material.

[0049] Step two, preparation of printable TS ink.

[0050] (1) 5 mL of 10 mg mL -1 TS water dispersion in 10 mL of dimethyl sulfoxide (DMSO) solution, ultrasonic mixing, centrifugation at 10000 rpm for 15 min, and the precipitate is reserved.

[0051] DMSO solvent has low boiling point and fast evaporation characteristics, which is beneficial to ink drying in the printing process, so that the printed pattern is clear and not easy to blur.

[0052] (2) The precipitate is added to 5 mL of DMSO solution and uniformly dispersed by ultrasonic, and centrifuged at 2500 rpm for 10 min, and the precipitate is reserved, which is the printable TS ink. The ink is black and viscous, has fluidity, and after extrusion, it is a continuous straight line, and has good shape retention.

[0053] Step three, construction of TS flexible pressure sensor.

[0054] (1) The electrode layer and the sensing layer are designed, drawn and imported using CAD, so as to realize accurate control and individualized regulation of the printed pattern.

[0055] (2) Adjust the printing conditions required for Ag ink and TS ink, set the printing parameters according to different printing thickness and device performance, and select a 25G needle with an inner diameter of 0.26 mm for printing, with a printing rate of 2 mm s -1 , and the printing air pressure is 15 kPa.

[0056] (3) The pretreated silicone film with a thickness of 0.2 mm is used as a flexible substrate and fixed on the microelectronic printing equipment platform (model: Shanghai Power Square Electronics Technology, Scienctific 3A), the Ag ink is placed in the needle cylinder, and the Ag electrode is printed on the substrate based on the printing parameters in step (2) and the pattern set in step (1). The thickness of the electrode is controlled by the number of printing layers, and in this embodiment, the thickness of the Ag electrode is limited to 40 μm, and the printing area is 10 mm 2 .

[0057] (4) After the Ag electrode is dried, the TS sensing layer is printed on the surface of the Ag electrode using the printing parameters in step (2) and the pattern set in step (1), and the thickness of the sensing layer is controlled by the number of printing layers.

[0058] (5) A layer of Ag electrode with a thickness of 40 μm is printed on one side of the sensing layer using the printing parameters in step (2), that is, a flexible pressure sensor with a sandwich structure (Ag / TS / Ag) is assembled, and the sandwich structure sensor is peeled off from the flexible substrate.

[0059] (6) The sandwich-structured flexible pressure sensor with different thickness of TS sensing layer was printed and mounted on a single column tensile test machine to compress at a speed of 0.5 mm min -1 -1, and the resistance change of the sensor under different pressures was tested by connecting the sensor with Keysight 4200 semiconductor parameter analyzer through the wire under the voltage setting of 1 V.

[0060] Table 1: Relationship between the number of printed layers, the thickness of TS sensing layer, and the highest sensitivity of the device

[0061] As shown in Table 1, the sensitivity showed a trend of first increasing and then decreasing with the thickness of the sensing layer. Considering the sensitivity and mechanical properties of the device (thinner films are more likely to deform, thus causing significant changes in resistance when subjected to external forces, and leading to a decrease in the mechanical stability of the material, thus affecting its sensitivity), the thickness of the TS sensing layer was finally limited to 15 μm in this embodiment, and the sensitivity of the sensor constructed at this time was the highest, which was 7.8 kPa -1 .

[0062] Microelectronic printing technology can help construct ultra-thin flexible pressure sensors, which are simple and easy to control in shape and structure, and are conducive to the construction of large-area flexible electronic devices.

[0063] Related performance tests.

[0064] The resistance ratio marked on the ordinate in FIGS. 7-10 is defined as the ratio of the changed resistance to the initial resistance.

[0065] FIG. 7 is a response time and recovery time test diagram of the TS flexible pressure sensor. As can be seen from the diagram, when a pressure of 0.25 kPa is applied, the sensor exhibits ultrafast response time (50 ms) and recovery time (70 ms).

[0066] FIG. 8 is a minimum detection limit test diagram of the TS flexible pressure sensor. As shown in FIG. 8a, the sensor can detect the transient current change caused by the 0.2 Pa micro-pressure generated by a sesame seed (2 mg), which is superior to the minimum detection limit of the pressure sensor reported in the prior art.

[0067] FIG. 9 is a 10000-cycle stability test diagram of the TS flexible pressure sensor. A pressure of 0.5 kPa was alternately loaded and unloaded on the flexible pressure sensor, and the relative current change after 10000 cycles was detected. As can be seen from the diagram, there is no significant signal degradation phenomenon after multiple cycles.

[0068] Comparative Example

[0069] A sandwich structure flexible pressure sensor (Ti3C2 flexible pressure sensor) with ultrathin Ti3C2 nanosheets (prepared in step one in Example One) as the sensing layer was prepared by the same method as shown in step two and step three in Example One, except that ultrathin Ti3C2 nanosheets were used instead of TS as the main sensing layer material, and the relevant parameters were unchanged.

[0070] Figure 10 is a comparison chart of the sensitivity of TS and Ti3C2 flexible pressure sensors. The sensitivity of the self-supporting TS flexible pressure sensor without a flexible substrate support is 7.8 kPa -1 , and the sensitivity of the Ti3C2 flexible pressure sensor is 1.7 kPa -1 . This is mainly due to the introduction of large size and wrinkle microstructure, which leads to an increase in contact site change, improves the relative resistance change, and thus improves the compression sensitivity.

[0071] Application Example

[0072] (1) To explore the monitoring ability of high-sensitivity flexible pressure sensors for small pressure signals, the flexible pressure sensor is integrated with a signal processing module (including a 12-bit high-precision analog-to-digital converter (12-bit ADC), a 32-bit microcontroller unit (MCU), a low-bias voltage operational amplifier (Op-Amp), and a low-voltage demodulator (LDO)) and a wireless communication module (2.4 GHz ceramic antenna and Bluetooth) to build a complete wireless sleep breathing monitoring system for real-time monitoring of small sleep breathing signals and identification of different breathing states to provide alarm feedback for abnormal breathing states. The basic power is provided by a 4.2V lithium battery, and the operational amplifier can amplify the small breathing signals detected by the sensor to ensure the accuracy of the data. The monitoring signal is converted and processed by the ADC and MCU processor, and transmitted wirelessly to the smart phone terminal through the Bluetooth module. Figure 11 is a schematic diagram of the system structure of the wireless sleep breathing monitoring system.

[0073] (2) Initial settings are made, and necessary monitoring software is installed on the smart phone terminal and paired with the wireless sleep breathing monitoring system Bluetooth module.

[0074] (3) The system is calibrated to ensure that the operational amplifier can accurately amplify the small breathing signals and accurately convert and process them through the ADC and MCU processor.

[0075] (4) The system is configured to use related double sampling technology to accurately monitor the fluctuations of the breathing signal, to improve the sampling accuracy and reduce the influence of noise on the signal.

[0076] (5) Select a group of volunteers, place the flexible pressure sensor under the nose of the human body, monitor the pressure signal changes caused by respiratory airflow, as people exhale and inhale will produce positive or negative pressure airflow, through the pressure sensor to collect the pressure generated by the airflow to obtain the ventilation flow, after converting it into a pulse signal, it can be used to characterize the volunteer's exhalation and / or inhalation, and thus the real-time monitoring data of sleep breathing can be obtained, and normal breathing, rapid breathing, deep breathing and asphyxia state can be accurately identified;

[0077] Table 2: Judgment criteria for adult respiratory state

[0078] (6) As shown in Table 2, when the wireless sleep breathing monitoring system monitors that the respiratory signal pause is more than 10s, it will be judged as apnea, i.e. asphyxia, at this time the monitoring system timely triggers an alarm signal to ensure the health and safety of the user;

[0079] (7) Collect experimental data and analyze the monitoring accuracy of the system, and find that the use of the high-compression, antioxidant titanium carbide flexible pressure sensor has the ability to accurately identify different breathing states, which can provide a reliable health monitoring tool for users, and the measured data results can also be used as a reference for hospitals to develop treatment plans.

[0080] The above shows and describes the basic principles, main features and advantages of the present application. However, the above description is only a specific embodiment of the present application, and the technical features of the present application are not limited to this. Any person skilled in the art who does not deviate from the technical solution of the present application can obtain other embodiments, which should be covered in the patent scope of the present application.

Claims

1. A high-compression, oxidation-resistant, flexible titanium carbide pressure sensor, characterized in that, The sensitivity of the titanium carbide flexible pressure sensor reaches 7.8 kPa -1 The response time is 50 ms under the application of 0.25 kPa pressure; and the preparation method of the titanium carbide flexible pressure sensor is as follows: 1) Multilayer Ti3C2 is prepared by wet etching Ti3AlC2, and ultrasonic exfoliation is used to obtain ultrathin Ti3C2 nanosheets; 2) The ultrathin Ti3C2 nanosheets are mixed with Na2S·9H2O to perform a hydrothermal reaction, and a large-size, wrinkled Ti3C2 sheet is constructed, denoted as TS; 3) The TS is dispersed in a dimethyl sulfoxide solution, mixed and centrifuged, and the precipitate is reserved to obtain a TS printing ink; 4) On a microelectronic printing equipment platform, an Ag electrode is printed on a flexible substrate by using conductive silver paste, the Ag electrode is dried, a sensing layer is printed on the Ag electrode by using the TS printing ink, then an Ag electrode is printed on one side of the sensing layer, the flexible substrate is peeled off, and a flexible pressure sensor with an Ag / TS / Ag sandwich structure is obtained. In step 4), the thickness of the sensing layer is 15 μm.

2. A high-compression, oxidation-resistant, flexible titanium carbide pressure sensor as claimed in claim 1, wherein, In step 2), the molar ratio of the ultrathin Ti3C2 nanosheets to Na2S·9H2O is 1:5-240, the hydrothermal reaction temperature is 25-240 °C, and the reaction time is 12-24 h.

3. The method of making a high-compression, oxidation-resistant, flexible titanium carbide pressure sensor of claim 1, wherein, In Step 4), a 25G needle having an inner diameter of 0.26 mm was used at a printing rate of 2 to 4 mm / s and a printing air pressure of 5 to 25 kPa. -1 , a printing rate of 2 to 4 mm / s, and a printing air pressure of 5 to 25 kPa.

4. A high-compression, oxidation-resistant, flexible titanium carbide pressure sensor as claimed in claim 1, wherein, In step 4), the printed area of the Ag electrode is 10 mm 2 ~ 500 mm 2 , and the thickness of the Ag electrode is not less than 40 μm.

5. A high-compression, oxidation-resistant, flexible titanium carbide pressure sensor as claimed in claim 1, wherein, The minimum detection limit of the titanium carbide flexible pressure sensor is 0.2 Pa.

6. A high-compression, oxidation-resistant, flexible titanium carbide pressure sensor as claimed in claim 1, wherein, The titanium carbide flexible pressure sensor can be stably cycled for more than 10,000 times under the conditions of 0.5 kPa pressure loading and unloading.

7. Application of the high-compression, oxidation-resistant titanium carbide flexible pressure sensor according to any one of claims 1-6 in a wireless respiratory monitoring system.

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