Flexible sensor and preparation method and application thereof

Abstract

The invention discloses a flexible sensor and a preparation method and application thereof. The flexible sensor comprises the following preparation raw materials: natural latex, a PEDOT: PSS solution, a deep eutectic solvent, zinc oxide, sodium fluorosilicide, a vulcanizing agent, a vulcanization accelerator, a foaming agent and an anti-aging agent. The natural latex, the PEDOT: PSS solution and the deep eutectic solvent are taken as raw materials, and the prepared flexible sensor has the characteristics of excellent mechanical property, wide response range, high sensitivity, short response time, high stability and fatigue resistance. Due to the excellent characteristics, the sensor can be used for monitoring various motions, human respiration and sleep, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a flexible sensor and a preparation method and application thereof. Background Art

[0002] In recent years, with the rapid development of wearable electronics, sports health monitoring, and Internet of Things (IoT) technologies, the demand for sensors that can continuously and seamlessly perceive the human body's physiological state and environmental information has become increasingly urgent. As the core sensing unit of these intelligent systems, skin-like sensors are responsible for collecting key physiological parameters (such as heart rate, body temperature, and movement posture) and external environmental data (such as temperature and humidity). They provide users with real-time, accurate health assessments and feedback, and are a key cornerstone for personalized smart health management.

[0003] Traditional sensors are generally constructed using rigid materials such as silicon-based semiconductors, metal conductors, or ceramics. Although these materials perform well in conventional electronic devices, their inherent rigidity creates significant wear comfort issues. When used in scenarios that require long-term, close-fitting wear (such as chronic disease medical monitoring, sports performance tracking, or daily health management), these rigid sensors have difficulty adapting to the complex curved morphology and dynamic activities of the human body, and can easily cause local compression, skin irritation, and even restrict natural movement, seriously affecting user experience and long-term wear compliance. The huge mismatch in mechanical properties between this material and human tissue has become a bottleneck hindering the in-depth application of traditional sensors in the wearable field.

[0004] To overcome these limitations, wearable flexible sensors have emerged and become a research hotspot. These sensors typically utilize a flexible polymer substrate combined with functional sensitive materials, designed to mimic the softness and stretchability of skin. They can dynamically conform to the curves of the human body, naturally extending and bending with limb movement, greatly improving wearer comfort and applicability. They are particularly suitable for long-term, dynamic vital sign monitoring and human-computer interaction applications.

[0005] However, flexible sensors under the current technology route often have difficulty in achieving a balance between flexibility and overall performance. The core challenges they generally face include: (1) Low electrical conductivity: The electrical conductivity of flexible conductive materials (such as some polymer composites) is often significantly lower than that of traditional metal materials, affecting signal transmission efficiency and signal-to-noise ratio; (2) Insufficient sensitivity: The ability to perceive environmental changes is limited, making it difficult to meet high-precision detection requirements; (3) Narrow response range: Its effective working range (such as pressure and strain range) is limited and cannot cover the wide range of dynamic changes that may be caused by human activities; (4) Poor mechanical properties: It is difficult to balance flexibility and mechanical strength, and fatigue damage, fracture or performance degradation are prone to occur, affecting the reliability and service life of the sensor. These performance shortcomings have seriously restricted the practicality and popularity of flexible sensors in complex application scenarios.

[0006] Therefore, developing a flexible sensor with high sensitivity, wide response range, excellent mechanical properties (such as high elasticity and toughness) and reliable electrical properties has become an urgent need to break through the existing technological bottleneck and promote the development of the next generation of high-performance wearable devices. Summary of the Invention

[0007] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, in a first aspect, the present invention provides a flexible sensor having the characteristics of high conductivity, high sensitivity, wide response range and good comprehensive mechanical properties.

[0008] The second aspect of the present invention also provides a method for preparing a flexible sensor.

[0009] The third aspect of the present invention further provides an application of a flexible sensor.

[0010] According to a first aspect of the present invention, a flexible sensor is provided, comprising the following raw materials: natural rubber latex, PEDOT:PSS solution, deep eutectic solvent, zinc oxide, sodium fluorosilicon dioxide, a vulcanizing agent, a vulcanization accelerator, a foaming agent, and an antioxidant;

[0011] Based on 100 parts by weight of the natural rubber latex, the amount of the PEDOT:PSS solution is 0.1 to 1 part by weight, the amount of the deep eutectic solvent is 5 to 25 parts by weight, the amount of zinc oxide is 1 to 5 parts by weight, the amount of sodium fluoride is 0.5 to 2 parts by weight, the amount of the vulcanizing agent is 1 to 5 parts by weight, the amount of the vulcanization accelerator is 2 to 8 parts by weight, the amount of the foaming agent is 2 to 8 parts by weight, and the amount of the antioxidant is 0.5 to 2 parts by weight.

[0012] According to a preferred embodiment of the present invention, based on 100 parts by weight of the natural rubber latex, the deep eutectic solvent is used in an amount of 10 to 25 parts by weight.

[0013] According to a preferred embodiment of the present invention, the deep eutectic solvent includes a hydrogen bond acceptor and a hydrogen bond donor; wherein the hydrogen bond acceptor includes a quaternary ammonium salt compound or choline chloride; the hydrogen bond donor includes at least one of ethylene glycol, propylene glycol, glycerol, butanediol, pentanediol, triethanolamine or urea.

[0014] According to a preferred embodiment of the present invention, the deep eutectic solvent is prepared by the following method:

[0015] The hydrogen bond donor and the hydrogen bond acceptor are mixed according to the molar ratio, and stirred under heating to obtain the product.

[0016] According to a preferred embodiment of the present invention, the vulcanizing agent comprises sulfur. According to a preferred embodiment of the present invention, the sulfur is selected from at least one of sublimed sulfur, insoluble sulfur, soluble sulfur, and oil-extended sulfur.

[0017] According to a preferred embodiment of the present invention, the vulcanization accelerator is selected from at least one of sulfenamide accelerators, thiazole accelerators, thiuram accelerators or guanidine accelerators.

[0018] According to a preferred embodiment of the present invention, the vulcanization accelerator is selected from at least one of accelerator CBS, accelerator MBS, accelerator TMTM, accelerator ZDMC, accelerator ZDEC, accelerator ZDBC, accelerator DPG, accelerator DOTG, accelerator ETU, accelerator ZMBT, and accelerator DETU.

[0019] According to a preferred embodiment of the present invention, the antioxidant is selected from at least one of quinoline, benzimidazole, hindered phenol or amine antioxidants.

[0020] According to a preferred embodiment of the present invention, the quinoline antioxidant can be a 2,2,4-trimethyl-1,2-dihydroquinoline polymer; the benzimidazole antioxidant can be 2-mercaptobenzimidazole; the amine antioxidant can be selected from one or more of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N-isopropylphenyl-N'-phenyl-p-phenylenediamine, N-cyclohexyl-N'-phenyl-p-phenylenediamine and N-phenyl-2-naphthylamine; the hindered phenol antioxidant includes antioxidant WSL (CAS No. 68610-51-5).

[0021] The flexible sensor according to the embodiment of the present invention has at least the following beneficial effects:

[0022] The flexible sensor, fabricated using natural rubber latex, a PEDOT:PSS solution, and a deep eutectic solvent, exhibits excellent mechanical properties, a wide response range, high sensitivity, fast response time, high stability, and fatigue resistance. These exceptional properties make the sensor suitable for various sports monitoring, as well as for monitoring human respiration and sleep, offering broad application prospects.

[0023] According to a second aspect of the present invention, there is provided a method for the flexible sensor as described above, comprising the following steps:

[0024] S1, mixing natural rubber latex, PEDOT:PSS solution, deep eutectic solvent, vulcanizing agent and antioxidant to obtain a mixed solution;

[0025] S2, mixing a vulcanization accelerator and a foaming agent with the mixed solution, mechanically stirring and foaming to obtain a foaming solution;

[0026] S3, mixing zinc oxide, sodium silicofluoride and the foaming liquid, stirring, and solidifying to obtain the product.

[0027] According to a preferred embodiment of the present invention, in step S1, the stirring time is 1 to 3 hours.

[0028] According to a preferred embodiment of the present invention, the rotation speed of the mechanical stirring is 800 rpm to 1500 rpm.

[0029] According to a preferred embodiment of the present invention, the curing temperature is 80°C to 120°C.

[0030] According to a preferred embodiment of the present invention, the curing time is 1 to 3 hours.

[0031] The method for preparing a flexible sensor according to an embodiment of the present invention has at least the following beneficial effects:

[0032] The flexible sensor, prepared by blending and foaming natural rubber latex, a PEDOT:PSS solution, and a deep eutectic solvent, exhibits excellent mechanical properties, a wide response range, high sensitivity, fast response time, and fatigue resistance. These remarkable properties make the sensor suitable for various sports monitoring, human respiration, and sleep monitoring, and have broad application prospects.

[0033] A third aspect of the present invention provides an application of the flexible sensor in human motion monitoring, temperature monitoring, humidity detection, and respiration monitoring.

[0034] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0036] Figure 1 1 is a conductivity graph of the flexible sensor of Examples 1 to 5 of the present invention and Comparative Example 1;

[0037] Figure 2 is a stress-strain curve diagram of the flexible sensor of Example 1 of the present invention at 50% strain;

[0038] Figure 3 1 is a physical diagram of the flexible sensor in Example 1 of the present invention in pressurized and released states;

[0039] Figure 4 1 is a stress-strain curve diagram of the flexible sensor under different set strains according to Example 1 of the present invention;

[0040] Figure 5 is a graph showing ΔR / R0 values ​​of the flexible sensor of Example 1 of the present invention at different strains and different frequencies;

[0041] Figure 6 is a response and recovery time diagram of the flexible sensor according to Example 1 of the present invention;

[0042] Figure 7 is a graph showing the change in relative resistance of the flexible sensor according to Example 1 of the present invention as a function of stress;

[0043] Figure 8 is a stability diagram of the flexible sensor of Example 1 of the present invention after 1000 compression cycles under a stress of 5 kPa;

[0044] Figure 9 is a resistance response diagram of the flexible sensor according to Example 1 of the present invention as it changes with temperature;

[0045] Figure 10 is a resistance response diagram of the flexible sensor according to Example 1 of the present invention as humidity changes;

[0046] Figure 11 is a resistance response diagram of the flexible sensor according to Example 1 of the present invention after detecting human motion;

[0047] Figure 12 is a diagram showing the relationship between the flexible sensor in Example 1 of the present invention monitoring respiration and resistance change;

[0048] Figure 13 is a graph showing the relationship between respiration and resistance when monitoring different walking speeds using the flexible sensor of Example 1 of the present invention;

[0049] Figure 144 is a diagram showing resistance changes at different locations of the flexible sensor according to Example 1 of the present invention during sleep monitoring. DETAILED DESCRIPTION

[0050] The following are specific embodiments of the present invention, and the technical solutions of the present invention are further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0051] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0052] Some of the raw materials used in the examples and comparative examples of the present invention are as follows:

[0053] Preparation of deep eutectic solvent: choline chloride (ChCl) and urea were mixed in a molar ratio of 1:2, and stirred at 80° C. for 1 hour to obtain a clear and transparent DES solution; the solution was set aside.

[0054] PEDOT:PSS solution: purchased from Aladdin;

[0055] Sodium silicofluoride: purchased from Aladdin Company;

[0056] Natural rubber latex: industrial grade, Shenzhen Jitian Chemical Co., Ltd.

[0057] Curing agent: sulfur; commercially available;

[0058] Vulcanization accelerators: accelerator ZDEC and accelerator ZMBT; purchased from Dongguan Benke Latex Co., Ltd.;

[0059] Foaming agent: potassium oleate; purchased from Aladdin Company;

[0060] Anti-aging agent: Omnofa Winstay L (WSL) antioxidant;

[0061] The compression test of the present invention was completed at room temperature using a CMT2103 electronic universal testing machine from Shenzhen Sansi Testing Equipment Co., Ltd., with the crosshead speed set at 500 mm / min. The piezoresistance data of the flexible sensor was obtained from 7 1 A 2-digit precision digital multimeter (Keithley DMM7510) was used in sync with the CMT2103 testing machine to record relative resistance changes (ΔR / R0 = (R-R0) / R0), where R and R0 represent the resistance under load and unload, respectively. During physiological monitoring, the sensor was affixed to the researcher's skin with tape, and the multimeter recorded the relative resistance change (ΔR / R0) in real time.

[0062] Example 1

[0063] This example provides a flexible sensor. The amounts of raw materials used in its preparation are shown in Table 1. The preparation method is as follows:

[0064] S1, mixing natural rubber latex, PEDOT:PSS solution, and deep eutectic solvent, and adding a vulcanizing agent and an antioxidant to the solution under stirring to obtain a mixed solution;

[0065] S2. Add the vulcanization accelerator and the foaming agent to the above-mentioned mixed solution under stirring, and continue stirring for 8 hours; then mechanically stir (1000 rpm) and foam to obtain a foaming solution;

[0066] S3. Add zinc oxide and sodium silicofluoride to the foaming liquid and stir for 90 seconds and 60 seconds respectively; then pour the foam into a cylindrical mold and solidify (100° C., 2 hours) to obtain the foam.

[0067] Examples 2 to 5

[0068] Examples 2 to 5 provide a series of flexible sensors. The amounts of raw materials used in their preparation are shown in Table 1. The preparation method is the same as that of Example 1.

[0069] Table 1 Example 1 to Example 5 (parts by weight)

[0070] Example 1 Example 2 Example 3 Example 4 Example 5 natural rubber latex 100 100 100 100 100 PEDOT:PSS solution 0.45 0.45 0.45 0.45 0.45 Deep eutectic solvents 10 2 15 20 25 zinc oxide 3 3 3 3 3 Sodium silicofluoride 1 1 1 1 1 vulcanizing agent 2 2 2 2 2 vulcanization accelerator 2 2 2 2 2 foaming agent 4 4 4 4 4 Antioxidants 1 1 1 1 1

[0071] Comparative Example 1

[0072] This example provides a flexible sensor (named PN), the raw material dosage and preparation method of which are the same as those in Example 1, except that no deep eutectic solvent is added.

[0073] Comparative Example 2

[0074] This example provides a flexible sensor (named DN), the raw material dosage and preparation method of which are the same as those in Example 1, except that no PEDOT:PSS solution is added.

[0075] Performance Testing

[0076] The flexible sensors of Examples 1 to 5 of the present invention and Comparative Example 1 were tested for electrical conductivity, and the results are as follows: Figure 1 As shown. Figure 1 It can be seen that the conductivity of the flexible sensor of Example 1 of the present invention is 3.9 times that of the flexible sensor of Comparative Example 1.

[0077] Furthermore, the mechanical properties of the flexible sensor of Example 1 of the present invention are explored as follows:

[0078] By testing the stress-strain curves of different flexible sensors (Example 1, Comparative Example 1 and Comparative Example 2) at 50% strain, the results are as follows: Figure 2As shown, compared with NR foam (natural rubber latex 100 parts, 2-mercaptobenzothiazole zinc (accelerator ZMBT) 1 part, zinc oxide 3 parts, sulfur 2 parts, diethyldithiocarbamate zinc (accelerator ZDEC) 1 part, sodium fluorosilicate 1.2 parts, antioxidant emulsion 1 part, potassium oleate 4 parts), Comparative Example 1 requires lower stress at the same strain. This is because the addition of PEDOT:PSS introduces a large amount of water, which evaporates during the rubber curing and drying process, resulting in a softer and fluffier structure. In contrast, the introduction of DES in Example 1 of the present invention did not significantly affect the mechanical properties of the flexible sensor.

[0079] Furthermore, the flexible sensor of Example 1 of the present invention was compressed (compression deformation 80%) and then released, and the results were as follows: Figure 3 As shown, the flexible sensor can quickly recover to its original shape after the compressive stress is released, indicating that the flexible sensor of the present application has excellent high elasticity.

[0080] Furthermore, the stress-strain curves of the flexible sensor of Example 1 of the present invention were tested under different strain settings (10%, 20%, 30%, 40%, 50%, and 60%). The results are as follows: Figure 4 As shown in (a), the flexible sensor performs very well at different compressive strains (10-60%). Once the external force is released, it can almost immediately return to its original state, indicating that it has excellent compressibility and recoverability. Furthermore, the flexible sensor was compressed at 80% strain for ten cycles and the stress-strain curve was tested. The results are shown in Figure 4 As shown in b, after ten cycles of strain compression, the unloading curve almost returns to its initial point. The compression process of the flexible sensor of Example 1 can be divided into two stages: the elastic zone (compression strain <50%), where the stress increases slowly due to the elastic bending of the cell wall; and the dense zone (compression strain >50%), where the stress continues to increase due to the mutual squeezing of the cell walls. It is worth noting that the stress-strain curve in the elastic zone almost forms a single quasi-linear slope region, which means that the prepared elastic foam is very soft and does not rupture during the compression process.

[0081] Furthermore, the sensing performance of the flexible sensor of Example 1 of the present invention was tested as follows:

[0082] The ΔR / R0 values ​​of the flexible sensor of Example 1 were used as piezoresistive sensors in compression-release cycles of 10%, 20%, 30%, 40%, 50% and 60%. Figure 5 As shown in a, the results show that under the same compressive strain, the relative resistance curves (R-R0) / R0 of the piezoresistive sensor almost overlap, indicating that the sensor of the present invention has excellent sensing stability and repeatability.

[0083] Furthermore, the flexible sensor of Example 1 was subjected to compression cycle tests at different compression rates, and the results are as follows: Figure 5 As shown in (b), the results still show good reversibility and stability. These two tests prove the reliability of the flexible sensor of the present invention.

[0084] Furthermore, the fast response and recovery time of the flexible sensor are key performance parameters of the sensor, so the present invention demonstrates the instant response behavior of the flexible sensor of Example 1, and the results are as follows Figure 6 As shown in the figure, at a compression speed of 500 mm / min and a compressive strain of 1%, the flexible sensor has a response time of 57 ms and a recovery time of 55 ms, indicating that the flexible sensor can detect very small changes, thereby providing accurate and agile sensing measurements. In addition, the recovery time of the sensor is better than the response time because the excellent mechanical properties enable the sensor to quickly return to its initial state.

[0085] Furthermore, the relative resistance value of the flexible sensor of Example 1 of the present invention was tested as a function of stress and the sensitivity was calculated (the sensitivity is denoted as S, which is defined as S = ((R-R0) / R0) / ΔP, where R0 and R are the resistance values ​​before and after the pressure is applied, respectively, and ΔP represents the pressure change). The results are as follows: Figure 7 The resistance sensitivity of the flexible sensor of the present invention can be divided into four parts: (i) when the compressive stress range is 0-5kPa, the sensitivity S is 11.18kPa -1 (ii) When the compressive stress range is 5–11.5 kPa, the sensitivity S is 3.184 kPa -1 (iii) When the compressive stress range is 11.5–80 kPa, the sensitivity S is 0.2883 kPa -1 (iv) When the compressive stress range is 80–180 kPa, the sensitivity S is 0.1066 kPa -1 , which provides it with a wide response range. In the pressure range of 0–5kPa, the pores of the sensor deform significantly, resulting in more contact points between the conductive materials in adjacent pores. This creates a large number of conductive channels, causing the resistance to drop rapidly. As the pressure increases (5–11.5kPa and 11.5–80kPa), the increase in the contact area of ​​the conductive material in the pores decreases relatively, and the sensitivity also decreases accordingly. In the range of 80–180kPa, when the stress increases to a certain extent, the three-dimensional porous structure gradually changes to a layered structure. At this point, the contact area of ​​the conductive material no longer changes significantly, the resistance change remains basically constant, and the sensitivity tends to saturation.

[0086] Furthermore, the present invention also explores the stability of the flexible sensor of Example 1. The flexible sensor of the present invention is subjected to a compression test (1000 cycles) with a compression strain of 50%. The corresponding signal is as follows: Figure 8 As shown, the sensing signal exhibited excellent reproducibility even after 1,000 compression cycles. The signal changes between two identical compression cycles were almost identical. This indicates that the flexible sensor of the present invention exhibits excellent fatigue resistance and maintains long-term reversible and stable performance, suggesting great potential for application.

[0087] Furthermore, in addition to strain sensing, the flexible sensor of the present invention also has temperature sensing capabilities. The conductivity of the flexible sensor of the present invention increases with increasing temperature. This is because the conductivity of PEDOT:PSS is enhanced and the ion mobility of the deep eutectic solvent increases with increasing temperature, thus giving the flexible sensor of the present invention temperature-dependent sensing characteristics. The flexible sensor of the present invention exhibits excellent sensor signal changes at different temperatures, such as Figure 9 As shown in a, the resistance change (ΔR / R0) gradually decreases as the temperature increases from 25°C to 45°C. In addition, by placing the flexible sensor in contact between a beaker of 20°C water and a beaker of 80°C water, the resistance change is observed and recorded. Figure 9 As shown in (b), the flexible sensor exhibits excellent sensing repeatability and stability as the temperature alternates between hot and cold.

[0088] In addition, the flexible sensor of the present invention responds to humidity changes. By performing humidification-dehumidification cycles between 11% to 33% RH, 75% RH and 95% RH, the real-time response curve of the flexible sensor was recorded. The results are shown in Figure 2. Figure 10 As shown, the flexible sensor's response increases with increasing relative humidity. In a higher relative humidity environment, more water molecules can be adsorbed, resulting in a larger change in resistance. All these results together indicate that the fabricated flexible sensor has broad application prospects in flexible wearable sensing devices.

[0089] Furthermore, the flexible sensor of the present invention is explored for applications in human motion monitoring, such as Figure 11 As shown, based on the flexible sensor being repeatedly pressed ( Figure 11 (a)), bending ( Figure 11 (b)) and torsion ( Figure 11 (c)) shows signal changes, showing excellent sensing stability. For the movement of different joints of the human body, including various finger bending angles ( Figure 11 (d))、Wrist bending( Figure 11 (e)) and elbow flexion ( Figure 11(f)), the sensor also exhibits a stable and repeatable electrical signal. The shape and intensity of the signal can be observed to vary with the movement of different body parts (such as fingers, wrists, and elbows). This signal variation can be used to distinguish movements of different body parts and assess the intensity of human movement.

[0090] Furthermore, the application of the flexible sensor of the present invention in real-time respiratory monitoring is explored. The flexible sensor is used to detect the nose ( Figure 12 (a))、Oral cavity( Figure 12 (b)) airflow near the mouth and deep breathing through the mouth ( Figure 12 (c)). It can be observed that the electrical signal of the sensor changes with the intensity of the exhaled airflow. In addition, the sensor was placed at 5cm, 10cm, 15cm and 20cm away from the mouth ( Figure 12 (d)), it can be observed that the longer the distance, the weaker the airflow reaching the sensor, which in turn leads to a weaker signal.

[0091] In addition, the flexible sensor of the present invention can also monitor human breathing at different intensities after exercise. Figure 13 As shown, the sensor displayed different airflow signals after the volunteers walked or ran at different speeds. It can be clearly seen that the faster the volunteers ran, the stronger the breathing signal detected by the sensor. These results demonstrate that the fabricated sensor can effectively monitor breathing under different conditions.

[0092] Furthermore, the flexible sensor of the present invention was attached to the abdomen, chest and mouth of volunteers to monitor the changes in ΔR / R0 during breathing. The results are as follows: Figure 14 As shown, Figure 14 The a in the graph represents the change in ΔR / R0 of the mouth, chest, and abdomen during apnea and normal breathing. While the volunteers slept, the sensor was able to detect the airflow near the mouth and the movement of the chest and abdomen. For normal breathing during sleep, all three curves showed a consistent and regular shape. However, when the volunteers held their breath to simulate apnea, Figure 14 b in Figure 14 c and Figure 14 The d in Figure 14 In the zoomed-in signal graph in Figure a, the sensor signal becomes a horizontal line. Importantly, sensor data from different body parts exhibit similar patterns, which avoids the risk of interference from single-site monitoring and ensures more accurate and reliable monitoring results. This result strongly demonstrates the effectiveness of this sensor in monitoring respiratory disorders during sleep.

[0093] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the scope of the present invention.

Claims

1. A flexible sensor, characterized in that: The method comprises the following preparation raw materials: natural rubber latex, PEDOT:PSS solution, deep eutectic solvent, zinc oxide, sodium fluorosiliconide, vulcanizing agent, vulcanization accelerator, foaming agent and antioxidant; Based on 100 parts by weight of the natural rubber latex, the amount of the PEDOT:PSS solution is 0.1 to 1 part by weight, the amount of the deep eutectic solvent is 5 to 25 parts by weight, the amount of zinc oxide is 1 to 5 parts by weight, the amount of sodium fluoride is 0.5 to 2 parts by weight, the amount of the vulcanizing agent is 1 to 5 parts by weight, the amount of the vulcanization accelerator is 2 to 8 parts by weight, the amount of the foaming agent is 2 to 8 parts by weight, and the amount of the antioxidant is 0.5 to 2 parts by weight.

2. The flexible sensor according to claim 1, wherein Based on 100 parts by weight of the natural rubber latex, the deep eutectic solvent is used in an amount of 10 to 25 parts by weight.

3. The flexible sensor according to claim 1, wherein The deep eutectic solvent includes a hydrogen bond acceptor and a hydrogen bond donor; wherein the hydrogen bond acceptor includes a quaternary ammonium salt compound or choline chloride; the hydrogen bond donor includes at least one of ethylene glycol, propylene glycol, glycerol, butanediol, pentanediol, triethanolamine or urea.

4. The flexible sensor according to claim 1, wherein The vulcanizing agent includes sulfur.

5. The flexible sensor according to claim 1, wherein The vulcanization accelerator is selected from at least one of sulfenamide accelerators, thiazole accelerators, thiuram accelerators or guanidine accelerators.

6. The flexible sensor according to claim 1, wherein The antioxidant is selected from at least one of quinoline, benzimidazole, hindered phenol or amine antioxidants.

7. A method for preparing the flexible sensor according to any one of claims 1 to 6, characterized in that: The steps include: S1, mixing natural rubber latex, PEDOT:PSS solution, deep eutectic solvent, vulcanizing agent and antioxidant to obtain a mixed solution; S2, mixing a vulcanization accelerator and a foaming agent with the mixed solution, mechanically stirring and foaming to obtain a foaming solution; S3, mixing zinc oxide, sodium silicofluoride and the foaming liquid, stirring, and solidifying to obtain the product.

8. The preparation method according to claim 7, characterized in that The rotation speed of the mechanical stirring is 800 rpm to 1500 rpm.

9. The preparation method according to claim 7, characterized in that The curing temperature is 80°C to 120°C.

10. Application of the flexible sensor according to any one of claims 1 to 6 in human motion monitoring, temperature monitoring, humidity detection, and respiration monitoring.

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