Preparation method of graphene doped synergistic n-hexane in-situ foaming high-sensitivity flexible pressure sensing material

Abstract

The application discloses a preparation method of a high-sensitivity flexible pressure sensing material with graphene doping and in-situ foaming of n-hexane, and belongs to the technical field of flexible electronics. The method constructs a microstructure by means of graphene doping and introduction of pores by n-hexane as a pore-forming agent. In the selection of raw materials, graphene as part of the conductive material improves the conductivity. At the same time, by virtue of the high-temperature volatile characteristics of n-hexane, especially the escape from the composite material system in the preheating process to form more pores in the material, the equivalent Young's modulus of the material is reduced, and the pressure sensitivity of the material is enhanced. In the application, the graphene is modified by a covalent bond modification method, and the dispersibility and dispersion stability in the silicone rubber are better. The pressure sensing material prepared by the method has a uniform distribution of surface pores, and the overall distribution of the surface pore sizes is similar and has no obvious difference.

Description

Technical Field

[0001] The invention belongs to the field of flexible pressure sensing technology, specifically relating to a method for preparing a high-sensitivity flexible pressure sensing material by graphene doping and synergistic in-situ foaming of n-hexane. Background Technology

[0002] With the development of information technology in recent years, the demand for high-performance tactile sensors for next-generation devices (such as electronic skin, IoT devices, and human-machine interfaces) has been increasing. To meet these requirements, contact sensors need high pressure sensitivity, wide sensing range, mechanical flexibility, and repeatability. Based on various sensing mechanisms, materials, and designs, the sensing mechanisms of tactile sensors are mainly classified into resistive, capacitive, piezoelectric, and triboelectric types. Among these types, resistive sensors convert applied pressure into a corresponding change in resistance, and due to their simple measurement scheme and relatively high reliability, they have been widely used. In the field of resistive flexible sensors, the research and development of conductive fillers mainly focuses on three aspects: carbon materials, metal particles, and metal nitrides. These three types of materials each have their own advantages and disadvantages, and all have promising practical applications.

[0003] Graphene, as a typical representative of two-dimensional carbon nanomaterials, has significant advantages over other types of conductive materials in terms of conductivity, flexibility, thermal conductivity, and safety, making it a hot topic in basic research and industrial-scale preparation technology development. Although many reported graphene-based composite materials show potential, their applicability as pressure sensors remains limited due to their high elastic modulus. Under pressure, the change in conductivity is mainly caused by the spatial deformation of the conductive particle network during composite deformation. Therefore, a low elastic modulus increases deformation and conductivity changes, resulting in high pressure sensitivity. Furthermore, reducing the modulus can improve the flexibility of the material, which is crucial in soft electronics such as wearable skin sensors. An effective method for reducing the modulus is to construct porous microstructures within the composite material.

[0004] Currently, conventional pore-forming methods in the industry generally have significant technical shortcomings. Traditional foaming methods and template-based pore-forming methods are difficult to precisely control pore size, pore distribution, and porosity, which easily leads to problems such as uneven pore size, local pore connectivity, and disordered micropore arrangement. This results in an unstable internal microstructure of the material. Furthermore, existing preparation processes cannot balance the material's structural stiffness and pressure sensitivity: if the number of pores is reduced, the overall rigidity and elastic modulus of the composite material are high, resulting in a small degree of deformation under stress. However, the internal conductive network is difficult to reconstruct effectively, and the pressure sensing sensitivity is greatly reduced. On the other hand, blindly increasing the porosity to reduce the modulus and improve sensitivity will destroy the overall structural integrity of the matrix, leading to a sharp decrease in the material's mechanical stiffness, a loose and easily deformable structure, and a poorer load-bearing capacity, which greatly reduces durability and stability. Summary of the Invention

[0005] This invention addresses the problems of low sensitivity and narrow measurement range of single magnetorheological elastomer flexible sensors by providing a method for preparing a high-sensitivity flexible pressure sensing material using graphene doping and synergistic in-situ hexane foaming.

[0006] This invention provides a method for preparing a highly sensitive flexible pressure sensing material with graphene doping and synergistic n-hexane in-situ foaming, comprising the following steps:

[0007] Step 1: Add graphene to KH-550 ethanol aqueous solution, disperse ultrasonically, heat in a water bath until all ethanol and water solvent in the mixed solution are vaporized, and then vacuum dry to obtain surface-modified graphene.

[0008] Step 2: After mixing the surface-modified graphene with silicone oil, ultrasonically disperse the mixture, then add silicone rubber and carbonyl iron powder and stir.

[0009] Step 3: After ultrasonically dispersing and cooling the blend from Step 2, add the curing agent and n-hexane, and stir until homogeneous to obtain the mixture;

[0010] Step 4: Add the mixture to an aluminum container for vacuum treatment, then place the mixture into a mold for preheating, then demold the mixture onto drying paper and place it in a vacuum drying oven to dry, thus obtaining a highly sensitive flexible pressure sensing material.

[0011] Further, in step 1, the concentration of the KH-550 ethanol aqueous solution is 1wt%~2wt%; the mass ratio of graphene to KH-550 ethanol aqueous solution is 1:20~50;

[0012] Further, in step 1, the ultrasonic dispersion time is 1~2h; the water bath heating temperature is 95~100℃ and the time is 30~40min; the drying temperature is 70~90℃ and the time is 0.5~1h.

[0013] Further, the surface-modified graphene: silicone oil: silicone rubber: carbonyl iron powder: n-hexane = (1~10):(1.6~16.6):(4.1~43):(20~180):(1~20).

[0014] Furthermore, the curing agent is a silane coupling agent, and the mass ratio of the curing agent to the silicone rubber is 1:8~12.

[0015] Further, in step 2, the surface-modified graphene and silicone oil are stirred for 10-20 minutes before ultrasonic dispersion, and the ultrasonic time is 1-2 hours; the blend is stirred for 10-20 minutes.

[0016] Furthermore, in step 3, the ultrasonic dispersion time of the blend is 20-30 min; the stirring time after adding the curing agent and n-hexane is 5-30 min.

[0017] Further, in step 4, the vacuum treatment is performed in a vacuum drying oven at a pressure of -0.1 to -0.15 MPa for 15 to 20 minutes.

[0018] Furthermore, in step 4, the preheating conditions are a heating rate of 2-3℃ / min to 50-80℃ for 40-60 minutes.

[0019] Furthermore, in step 4, the vacuum drying temperature is 95~110℃ and the time is 1~1.5h.

[0020] The beneficial effects of this invention are as follows:

[0021] The method of this invention can construct a microporous structure inside the elastomer by adding graphene material and using n-hexane as a pore-forming agent. The microporous structure prepared by the method of this invention is uniformly distributed on the material surface and the difference in micropore size is small, which can improve the electrical properties of the material such as sensitivity.

[0022] The method of this invention employs a staged solvent dispersion approach during the hexane pore-forming process, ensuring uniform mixing of hexane and suspension. This allows for better dispersion from the material content to form uniform pores during pore formation at a specific temperature. Furthermore, it addresses the shortcomings of traditional preparation processes, such as inconsistent pore size, interconnected pores, and pore wall collapse and cracking, making it difficult to control the pore-forming effect. Before curing, this invention performs a preheating treatment, allowing hexane to slowly diffuse and uniformly disperse within the elastomer matrix during gradient preheating and isothermal treatment. This stabilizes the pore-forming sites in advance, while the gentle preheating initially shapes the matrix. During the subsequent high-temperature curing stage, hexane escapes at a uniform and stable rate, precisely forming a three-dimensional microporous structure with uniform pore size, regular arrangement, and good sealing, fundamentally avoiding the defects of conventional pore-forming methods. Attached Figure Description

[0023] Figure 1 The pore sizes generated at different preheating temperatures after adding hexane in the method of this invention;

[0024] Figure 2 The pore sizes generated at different preheating temperatures after adding n-hexane in the comparative proportions of this invention;

[0025] Figure 3 These are scanning electron microscope images of the materials prepared in Example 1 of the method of the present invention;

[0026] Figure 4 The pressure-resistance curve of the material prepared in Example 1 of the method of the present invention;

[0027] Figure 5 The material cycling performance curve prepared in Example 1 of the method of the present invention;

[0028] Figure 6 Application testing of the material prepared in Example 1 of the method of the present invention in wearable devices. Detailed Implementation

[0029] The present invention will now be further described with reference to the accompanying drawings.

[0030] A method for preparing a highly sensitive flexible pressure sensing material with graphene doping and synergistic n-hexane in-situ foaming includes the following steps:

[0031] Step 1: Weigh the raw materials according to the mass ratio of surface-modified graphene: silicone oil: silicone rubber: carbonyl iron powder: n-hexane = (1~10):(1.6~16.6):(4.1~43):(20~180):(1~20); preferably, the mass ratio of surface-modified graphene: silicone oil: silicone rubber: carbonyl iron powder: n-hexane = (1.3~8.5):(2.08~14.11):(5.33~36.55):(26~153):(1.3~17); first, stir the surface-modified graphene and silicone oil thoroughly for 10~20 min, and then place them in an ultrasonic disperser and ultrasonically disperse them at an oscillation frequency of 25~30 kHz for 1~2 h; the dynamic viscosity of the silicone oil is 200~800 Pa·s.

[0032] Step 2: Add silicone rubber and carbonyl iron powder to the above solution and stir for 10-20 minutes. Then, place the mixture in an ultrasonic disperser and ultrasonically disperse it at an oscillation frequency of 25-30 kHz for 20-30 minutes to obtain a black paste-like mixture. After the black paste-like mixture cools, add a curing agent and n-hexane and stir for 5-30 minutes. The curing agent is a silane coupling agent, and the mass ratio of the curing agent to the silicone rubber is 1:8-12.

[0033] Step 3: Place the mixed solution into a vacuum drying oven and vacuum treat it for 15 to 20 minutes at a pressure of -0.1 to -0.15 MPa to remove air bubbles from the mixed solution;

[0034] Step 4: Set the temperature of the vacuum drying oven to 50~80℃. Pour the black paste mixture into the mold and place it in the drying oven at room temperature for preheating treatment for 40min~1h to allow the material to solidify. The vacuum drying oven is heated to 50~80℃ at a heating rate of 2~3℃ / min.

[0035] Step 5: Set the temperature of the vacuum drying oven to 95~110℃ and the vacuum degree to -0.1~-0.15MPa. Demold the cured material onto the drying paper and then put the drying paper into the vacuum drying oven for 1~1.5h to allow the hexane inside the material to completely evaporate, thereby forming pores inside the material and obtaining a porous flexible pressure sensing material.

[0036] In some embodiments, the ratio of surface-modified graphene, silicone oil, silicone rubber, curing agent, carbonyl iron powder, and n-hexane affects the performance. Excessive amounts of modified graphene and carbonyl iron powder will prevent the mixture from being stirred and result in uneven material distribution; insufficient amounts will result in an insignificant magnetorheological effect. Excessive amounts of silicone oil and silicone rubber will make curing difficult and result in an insignificant magnetorheological effect; insufficient amounts will also prevent the mixture from being stirred and result in uneven material distribution. The dosage of the curing agent should be linearly related to the dosage of the silicone rubber, and the mass ratio should be controlled between 1:8 and 12, with an optimal ratio of 1:10. Excessive curing agent will result in an overly hard material, while insufficient amounts will make curing difficult. Excessive n-hexane will result in uncontrollable pores and excessively long curing times; insufficient amounts will result in insignificant pores. However, for practical applications with specific performance requirements, the preparation process can be adjusted accordingly. The method of this invention can prepare magnetorheological elastomers with pore sizes of 0.1–2 mm and porosity of 15%–60%, wherein the pore size and distribution on the material surface are uniform.

[0037] Example 1

[0038] Step 1: Weigh out 3g of surface-modified graphene, 8g of silicone oil, 13g of silicone rubber, 1.3g of curing agent, 72g of carbonyl iron powder, and 3.2g of n-hexane;

[0039] First, the surface-modified graphene and silicone oil were thoroughly stirred for 15 minutes, and then placed in an ultrasonic disperser and ultrasonically dispersed at an oscillation frequency of 25 kHz for 1 hour to obtain a mixed solution.

[0040] Surface-modified graphene was prepared by the following method:

[0041] Mix 1.5g KH-550, 48.5g anhydrous ethanol, and 50g deionized water thoroughly to prepare a 1.5% KH-550 ethanol aqueous solution. Add 3g graphene to the prepared KH-550 ethanol aqueous solution and then ultrasonically disperse it at a frequency of 25kHz for 2 hours to ensure complete reaction of the graphene. Place the fully reacted graphene-KH-550 ethanol aqueous solution in a water bath and heat until all the ethanol and water solvent in the solution are vaporized. Set the water bath heating temperature to 100℃ and heat for 30 minutes. Finally, dry it in a vacuum drying oven at 80℃ for 30 minutes to obtain surface-modified graphene. To prepare surface-modified graphene with different dosages, the amounts of KH-550, anhydrous ethanol, and deionized water can be increased or decreased proportionally. Since the preparation process is quite complicated and the surface-modified graphene can be stably stored at room temperature and away from light, it is recommended to prepare it in batches at once for easy access later.

[0042] Step 2: Add 13g of silicone rubber and 72g of carbonyl iron powder to the mixed solution and stir for 15 minutes. Then place it in an ultrasonic disperser and ultrasonically disperse at an oscillation frequency of 25kHz for 20 minutes to obtain a black paste mixture. After the black paste mixture cools, add 1.3g of curing agent and 3.2g of n-hexane and stir for 5 minutes.

[0043] Step 3: Place the mixed solution into a vacuum drying oven and vacuum treat it at -0.1MPa pressure for 20 minutes to remove air bubbles from the mixed solution;

[0044] Step 4: Set the temperature of the vacuum drying oven to 65℃, pour the black paste mixture into the mold, and place it in the drying oven at room temperature for preheating treatment for 1 hour to allow the material to solidify.

[0045] Step 5: Set the vacuum drying oven temperature to 100℃ and the vacuum degree to -0.1MPa. Demold the cured material onto drying paper, then place the drying paper in the vacuum drying oven for 1 hour to allow the hexane inside the material to completely evaporate, thus forming pores within the material, resulting in a porous flexible pressure sensing material. The softness is 0.657MPa. -1 .

[0046] like Figure 1 As shown in (b), the porous flexible pressure sensing material prepared in this embodiment has a uniform distribution of pores on its surface, and the overall distribution of pore diameters is similar with no obvious differences.

[0047] like Figure 3 As shown, the porous flexible pressure sensing material contains micron-sized pores and exhibits excellent dispersion uniformity of carbonyl iron powder and graphene within the material.

[0048] like Figure 4 As shown, the porous flexible pressure sensing material exhibits different resistance changes under different pressures, with a resistance change rate of 91.6% at a pressure of 3 kPa. Furthermore, the piezoresistive performance demonstrates good reversibility.

[0049] like Figure 5 As shown, the porous flexible pressure sensing material exhibits different resistance changes under different pressures, with a resistance change rate of 91.6% at a pressure of 3 kPa. Furthermore, the piezoresistive performance demonstrates good reversibility.

[0050] like Figure 6 As shown, the porous flexible pressure sensing material exhibits different electrical signal changes in response to different degrees of finger bending.

[0051] Example 2

[0052] The difference from Example 1 is that preheating is not performed in step 4, while the conditions for the remaining steps are the same. Specifically:

[0053] In step 4, the vacuum drying oven temperature is set to 50℃. After pouring the black paste mixture into the mold, it is placed in the drying oven at room temperature for preheating treatment for 1 hour to allow the material to solidify.

[0054] like Figure 1 As shown in (a), the porous flexible pressure sensing material prepared in this embodiment has a uniform surface porosity distribution, and the overall distribution of surface pore diameter is similar with no obvious differences. The surface pores are slightly sparser than those in Example 1.

[0055] Example 3

[0056] The difference from Example 1 is that preheating is not performed in step 4, while the conditions for the remaining steps are the same. Specifically:

[0057] In step 4, the temperature of the vacuum drying oven is set to 80℃. After pouring the black paste mixture into the mold, it is placed in the drying oven at room temperature for preheating treatment for 1 hour to allow the material to solidify.

[0058] like Figure 1 As shown in (c), the porous flexible pressure sensing material prepared in this embodiment has a uniform surface porosity distribution, and the overall distribution of surface pore diameter is similar with no obvious differences. The surface pores of the material are slightly denser than those in Example 1.

[0059] Example 4

[0060] The difference from Example 1 is that the mass of the surface-modified graphene in step 1 is changed, while all other conditions and parameters are the same; the mass of the surface-modified graphene is 5g.

[0061] Example 5

[0062] The difference from Example 1 is that the mass of the surface-modified graphene in step 1 is changed, while all other conditions and parameters are the same; the mass of the surface-modified graphene is 7g.

[0063] Example 6

[0064] The difference from Example 1 is that the mass of n-hexane in step 2 is changed, while all other conditions and parameters are the same; the mass of n-hexane is 4.8g.

[0065] Example 7

[0066] The difference from Example 1 is that the mass of n-hexane in step 2 is changed, while all other conditions and parameters are the same; the mass of n-hexane is 6.4g.

[0067] Comparative Example 1

[0068] The difference from Example 1 is that no n-hexane is added in step 2, while all other conditions and parameters are the same;

[0069] Comparative Example 2

[0070] The difference from Example 1 is that in step 2, the silicone rubber, carbonyl iron powder, curing agent, and n-hexane are simultaneously ultrasonicated; the conditions for the remaining steps are the same. Specifically:

[0071] In step 2, add silicone rubber and carbonyl iron powder to the mixed solution and stir for 15 minutes. Then add curing agent and n-hexane and place in an ultrasonic disperser to ultrasonically disperse at an oscillation frequency of 25 kHz for 25 minutes.

[0072] No voids were found in the prepared porous flexible pressure sensing material. After adding hexane, the mixed solution was subjected to ultrasonication. Due to the intense high-frequency vibration generated during ultrasonic dispersion, a large amount of frictional heat was produced, causing the temperature of the mixture system to rise above 50°C. Excessive temperature would cause partial solidification of the mixture before it could solidify. Furthermore, hexane itself has a low boiling point and is highly volatile; an environment above 50°C would cause all the hexane to evaporate before the material solidifies. Ultimately, the prepared high-sensitivity flexible pressure sensing material could not form a microporous structure.

[0073] Comparative Example 3

[0074] The difference from Example 1 is that preheating is not performed in step 4, while the conditions for the remaining steps are the same. Specifically:

[0075] Step 3: Place the mixed solution into a vacuum drying oven and vacuum treat it at -0.1MPa pressure for 20 minutes to remove air bubbles from the mixed solution;

[0076] Step 4: Set the vacuum drying oven temperature to 100℃ and the vacuum degree to -0.1MPa. Demold the material (after removing air bubbles in Step 3) onto drying paper, then place the drying paper in the vacuum drying oven for 1 hour to allow the hexane inside the material to completely evaporate, thus forming pores inside the material and obtaining a porous flexible pressure sensing material. A sudden temperature increase will cause the hexane to vaporize and evaporate rapidly, resulting in defects such as inconsistent pore size, localized interconnected pores, and pore wall collapse and cracking.

[0077] Comparative Example 4

[0078] The difference from Example 1 is that preheating at 35°C is used in step 4, while the conditions for the remaining steps are the same. Specifically:

[0079] In step 4, the vacuum drying oven temperature is set to 35℃. After pouring the black paste mixture into the mold, it is placed in the drying oven at room temperature for preheating treatment for 1 hour to allow the material to solidify. Figure 2 As shown, no pores were formed on the material surface. Due to the low drying and preheating temperature, the curing rate of the silicone rubber matrix was slow. At the same time, the hexane solvent in the black paste mixture slowly migrated upward in the black paste mixture, eventually floating on the surface of the solution and gradually evaporating completely. This made it impossible to leave air bubble channels inside the material, and ultimately the cured material surface failed to form a porous structure.

[0080] Comparative Example 5

[0081] The difference from Example 1 is that no surface-modified graphene is added in step 1, while all other conditions and parameters are the same;

[0082] Comparative Example 6

[0083] The difference from Example 1 is that surface-modified graphene and n-hexane are not added in step 2, while all other conditions and parameters are the same;

[0084] Performance testing

[0085] The performance of the graphene-based porous magnetorheological elastomer pressure sensing material was evaluated using indicators such as measurement range, sensitivity, and resistance retention rate. Compression testing was conducted according to GB / T 7759.1-2015. Specifically, copper foil material was adhered to both sides of the graphene-based porous magnetorheological elastomer, pressure was applied using a YC-LDS-2KN universal testing machine, and the material resistance was tested using a TH2830 bridge circuit. The test results are shown in Table 1 below:

[0086]

[0087] In summary, graphene itself possesses strong electrical conductivity, effectively improving the overall conductivity of composite materials. It also allows for more uniform mixing of internal components, preventing the agglomeration of magnetic particles and facilitating smoother force transmission. Hexane, with its low boiling point and high thermal volatility, naturally evaporates during the material's heating and curing process, leaving uniformly distributed micropores within the elastomer. These pores weaken the rigid constraints of the matrix material, reducing the overall hardness and rigidity of the material, making it more susceptible to deformation under stress, significantly improving pressure sensitivity, and broadening the application range of pressure detection.

[0088] This invention adds a preheating process to further optimize the pore formation quality and the regularity of the micropore structure. Through gradient preheating and isothermal treatment, this invention allows hexane to slowly diffuse and uniformly disperse in the elastomer matrix, stabilizing the pore formation sites in advance and preventing premature and sudden volatilization. Simultaneously, gentle preheating allows the matrix to initially solidify, and during the subsequent high-temperature curing stage, hexane escapes at a uniform and stable rate. This enables the precise formation of a three-dimensional microporous structure with uniform pore size, regular arrangement, and good sealing, fundamentally avoiding the defects of conventional pore formation methods.

[0089] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0090] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for preparing a highly sensitive flexible pressure sensing material with graphene doping and synergistic in-situ foaming of n-hexane, characterized in that, Includes the following steps: Step 1: Add graphene to KH-550 ethanol aqueous solution, disperse ultrasonically, heat in a water bath until all ethanol and water solvent in the mixed solution are vaporized, and then vacuum dry to obtain surface-modified graphene. Step 2: After mixing the surface-modified graphene with silicone oil, ultrasonically disperse the mixture, then add silicone rubber and carbonyl iron powder and stir. Step 3: After ultrasonically dispersing and cooling the blend from Step 2, add the curing agent and n-hexane, and stir until homogeneous to obtain the mixture; Step 4: Add the mixture to an aluminum container for vacuum treatment, then place the mixture into a mold for preheating, then demold the mixture onto drying paper and place it in a vacuum drying oven to dry, thus obtaining a highly sensitive flexible pressure sensing material.

2. The method for preparing the high-sensitivity flexible pressure sensing material according to claim 1, characterized in that, In step 1, the concentration of the KH-550 ethanol aqueous solution is 1wt%~2wt%; the mass ratio of graphene to KH-550 ethanol aqueous solution is 1:20~50.

3. The method for preparing the high-sensitivity flexible pressure sensing material according to claim 1, characterized in that, In step 1, the ultrasonic dispersion time is 1-2 hours; the water bath heating temperature is 95-100°C and the time is 30-40 minutes; the drying temperature is 70-90°C and the time is 0.5-1 hour.

4. The method for preparing the high-sensitivity flexible pressure sensing material according to claim 1, characterized in that, The surface-modified graphene: silicone oil: silicone rubber: carbonyl iron powder: n-hexane = (1~10): (1.6~16.6): (4.1~43): (20~180): (1~20).

5. The method for preparing the high-sensitivity flexible pressure sensing material according to claim 1, characterized in that, The curing agent is a silane coupling agent, and the mass ratio of the curing agent to the silicone rubber is 1:8~12.

6. The method for preparing the high-sensitivity flexible pressure sensing material according to claim 1, characterized in that, In step 2, the surface-modified graphene and silicone oil are stirred for 10-20 minutes before ultrasonic dispersion, and the ultrasonic time is 1-2 hours; the blend is stirred for 10-20 minutes.

7. The method for preparing the high-sensitivity flexible pressure sensing material according to claim 1, characterized in that, In step 3, the ultrasonic dispersion time of the blend is 20-30 min; the stirring time after adding the curing agent and n-hexane is 5-30 min.

8. The method for preparing the high-sensitivity flexible pressure sensing material according to claim 1, characterized in that, In step 4, the vacuum treatment is performed in a vacuum drying oven at a pressure of -0.1 to -0.15 MPa for 15 to 20 minutes.

9. The method for preparing the high-sensitivity flexible pressure sensing material according to claim 1, characterized in that, In step 4, the preheating conditions are a heating rate of 2-3℃ / min to 50-80℃ for 40-60 minutes.

10. The method for preparing the high-sensitivity flexible pressure sensing material according to claim 1, characterized in that, In step 4, the vacuum drying temperature is 95~110℃ and the time is 1~1.5h.

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