Porous carbon-based nanocomposite with intrinsic zero temperature coefficient, preparation method thereof and flexible pressure sensor with intrinsic zero temperature coefficient

Abstract

This invention provides a porous carbon-based nanocomposite material with intrinsically zero temperature coefficient, its preparation method, and a flexible pressure sensor with intrinsically zero temperature coefficient, belonging to the field of flexible pressure-sensitive materials technology. This invention uses PDMS as a flexible matrix and carbon black and carbon nanotubes as conductive fillers. It innovatively constructs a uniform and controllable pore structure within the material through a chemical foaming method that generates gas by the in-situ reaction of sodium bicarbonate and hydrochloric acid. Unlike existing technologies that rely on circuit compensation, this invention achieves precise cancellation of the positive and negative temperature coefficient effects of the material over a wide temperature range by synergistically controlling the ratio of carbon black to carbon nanotubes and the porosity of the material, thus obtaining a porous carbon-based nanocomposite material with intrinsically zero temperature coefficient. The preparation temperature and energy consumption are low, the process is simple and controllable, and the relative change rate of the material's resistance is less than 2% in the range of 25~100℃. When used in a flexible pressure sensor, it does not rely on external compensation circuits and exhibits both excellent piezoresistive sensitivity and temperature stability.

Description

Technical Field

[0001] This invention belongs to the field of flexible pressure-sensitive materials technology, specifically relating to an intrinsically zero temperature coefficient (ZeroTC) porous carbon polymer nanocomposites (PCPN), its preparation method, and a flexible pressure sensor with an intrinsically zero temperature coefficient. Background Technology

[0002] Flexible resistive pressure sensors have broad application prospects in wearable devices, health monitoring, and other fields. Carbon-based polymer nanocomposites are their core sensing materials. However, these materials generally suffer from resistance drift with ambient temperature, severely reducing the sensor's measurement accuracy. Existing technologies mainly employ two approaches: one is a circuit-level compensation strategy (such as Chinese patent application CN121298068A), which uses a Huygens bridge differential to offset temperature drift, but suffers from complex structures and multi-layer interface thermal mismatch leading to poor long-term reliability; the other is a material modification approach, such as Chinese patent application CN120793890A, which discloses a flexible pressure-sensitive material based on porous carbon sponge, a flexible pressure sensor, and its preparation method. This method uses a high-temperature (500℃~650℃) carbonization process to treat commercial melamine sponge and degreased cotton to obtain a conductive porous carbon skeleton. However, this approach suffers from high energy consumption, high brittleness during the carbonization process making it difficult to balance mechanical properties and conductivity, and its focus is on improving pressure-sensitive performance without addressing the temperature drift problem.

[0003] More importantly, there is a common technical bias in this field: that the temperature coefficient of resistance of polymer composites is an intrinsic property, and that it is not feasible to artificially control the positive and negative temperature coefficient effects to achieve a balance over a wide temperature range, and that external circuit compensation is the only option. Summary of the Invention

[0004] This invention addresses the aforementioned problems and overcomes the aforementioned technical biases. Its purpose is to provide a novel material preparation route, aiming to solve the problem that existing flexible pressure-sensitive materials cannot simultaneously achieve excellent pressure-sensitive properties and wide-temperature-range temperature stability. It provides a simple, low-energy-consumption porous carbon-based nanocomposite material with an intrinsic zero temperature coefficient. Unlike existing technologies that rely on high-temperature carbonization of a three-dimensional framework, this invention innovatively generates pores in situ within a liquid polymer matrix through chemical foaming. This achieves low-temperature preparation (100℃) while precisely controlling the key parameter of porosity. Specifically, it provides a porous carbon-based nanocomposite material with an intrinsic zero temperature coefficient, its preparation method, and a flexible pressure sensor with an intrinsic zero temperature coefficient.

[0005] The core concept of this invention lies in utilizing a controllable pore structure introduced through chemical foaming, which serves not only as a sensitive structure to enhance pressure-sensitive properties but also as a key regulatory means to physically block the thermal expansion of the matrix and enhance the positive temperature coefficient effect. By synergistically controlling the volume ratio of conductive fillers and the porosity of the material, the negative temperature coefficient effect within the material and the positive temperature coefficient effect of pore enhancement are precisely canceled out over a wide temperature range, thus achieving intrinsic zero temperature coefficient characteristics in a single-layer polymer composite material for the first time.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for preparing an intrinsically zero temperature coefficient porous carbon-based nanocomposite material, characterized by the following steps: S10, preparing a homogenized mixture composed of PDMS prepolymer, curing agent, carbon black, carbon nanotubes, and foaming agent; S20, adding hydrochloric acid to the mixture under continuous stirring to react with the foaming agent to generate bubbles, and stirring until the bubbles are uniform to obtain a foamed mixture; S30, curing the foamed mixture into a film at 90℃~110℃ for 45min~1h to obtain a single-layer intrinsically zero temperature coefficient porous carbon-based nanocomposite material. By synergistically controlling the amount of carbon black, carbon nanotubes, and foaming agent added in step S10, the negative and positive temperature coefficient effects of the intrinsically zero temperature coefficient porous carbon-based nanocomposite material in step S30 are ultimately mutually canceled out within the range of 25℃~100℃, resulting in an absolute value of the relative change rate of its electrical resistance ≤2%.

[0008] The method for preparing porous carbon-based nanocomposite materials with intrinsic zero temperature coefficient provided by the present invention may also have the following characteristics: in step S10, the PDMS prepolymer is vinyl-terminated polydimethylsiloxane, the curing agent is polymethylhydrosiloxane, and the mass ratio of PDMS prepolymer to curing agent is 10:1.

[0009] The method for preparing porous carbon-based nanocomposites with intrinsic zero temperature coefficient provided by the present invention may also have the following characteristics: wherein, in step S10, the average particle size of the carbon black is 100 nm to 200 nm, and the specific surface area is 42 m². 2 / g~48m 2 / g.

[0010] The method for preparing porous carbon-based nanocomposite materials with intrinsic zero temperature coefficient provided by the present invention may also have the following characteristics: in step S10, the outer diameter of the carbon nanotubes is 3nm~15nm and the length is 1.5μm~3μm.

[0011] The method for preparing porous carbon-based nanocomposite materials with intrinsic zero temperature coefficient provided by the present invention may also have the following feature: wherein, in step S10, the foaming agent includes sodium bicarbonate.

[0012] Preferably, in step S30, the heating temperature is 100°C.

[0013] Preferably, in step S30, the heating time is 1 hour.

[0014] The method for preparing porous carbon-based nanocomposites with intrinsic zero temperature coefficient provided by the present invention may also have the following characteristics: the method for synergistically controlling the amount of carbon black, carbon nanotubes and foaming agent added in step S10 is based on either a conductive filler mass fraction control method or a porosity control method. The conductive filler mass fraction control method involves fixing the mass of PDMS prepolymer, curing agent and foaming agent, fixing the sum of the mass of carbon black and carbon nanotubes, and adjusting the mass ratio of carbon black and carbon nanotubes so that the absolute value of the relative change rate of resistance of the porous carbon-based nanocomposites with intrinsic zero temperature coefficient is ≤2%. The porosity control method involves fixing the total mass of PDMS prepolymer, curing agent, carbon black and carbon nanotubes, and adjusting the mass of foaming agent so that the absolute value of the relative change rate of resistance of the porous carbon-based nanocomposites with intrinsic zero temperature coefficient is ≤2%.

[0015] The method for preparing porous carbon-based nanocomposite materials with intrinsic zero temperature coefficient provided by the present invention may also have the following characteristics: wherein, based on the conductive filler mass fraction control method, when the foaming agent is sodium bicarbonate, the ratio of the mass m1 of carbon black, the mass m2 of carbon nanotubes, the sum of the masses m3 of PDMS prepolymer and curing agent, and the mass m4 of foaming agent is 1:9:220:10.

[0016] The method for preparing porous carbon-based nanocomposites with intrinsic zero temperature coefficient provided by the present invention may also have the following characteristics: wherein, based on the porosity control method, when the foaming agent is sodium bicarbonate, the ratio of the mass m1 of carbon black, the mass m2 of carbon nanotubes, the sum of the masses m3 of PDMS prepolymer and curing agent, and the mass m4 of foaming agent is 1:4:110:15.

[0017] The present invention also provides a porous carbon-based nanocomposite material with intrinsic zero temperature coefficient, which is prepared by the preparation method of the porous carbon-based nanocomposite material with intrinsic zero temperature coefficient of any of the preceding claims.

[0018] The present invention also provides a flexible pressure sensor with intrinsic zero temperature coefficient, characterized in that the aforementioned porous carbon-based nanocomposite material with intrinsic zero temperature coefficient is used as the sensitive layer, and copper foil electrodes are fixed on the surface of the sensitive layer and leads are welded thereon.

[0019] The beneficial effects of this invention are:

[0020] (1) Achieving intrinsic zero temperature drift in materials: This invention introduces a controllable pore structure inside the material through chemical foaming. It utilizes the positive temperature coefficient effect of the pore-enhanced matrix material, which works synergistically with the positive temperature coefficient effect of carbon black itself and the negative temperature coefficient effect of carbon nanotubes. By precisely controlling the balance between the three, the positive and negative temperature coefficient effects cancel each other out in a wide temperature range. For the first time, a net temperature coefficient approaching zero (relative resistance change rate maintained within ±2%) is achieved in a single-layer polymer composite material in the range of 25℃~100℃. This fundamentally solves the temperature drift problem and completely eliminates the need for external compensation circuits.

[0021] (2) The process is green and simple, and saves energy significantly: Compared with the existing high temperature carbonization method (500℃~650℃), the maximum temperature of the chemical foaming and curing process of the present invention is only about 100℃, which greatly reduces energy consumption, makes the operation safer and simpler, and is easy to mass-produce.

[0022] (3) Structural parameters are independently controllable and performance is adjustable: the porosity is linearly adjusted by the amount of foaming agent and the filler ratio is controlled separately. The two key parameters can be independently and precisely controlled to achieve flexible design of the zero temperature coefficient window, which is an advantage that existing technologies that rely on natural or carbonized sponge skeletons do not have. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating the preparation process of the porous carbon-based nanocomposite material with intrinsic zero temperature coefficient according to Example 1 of the present invention.

[0024] Figure 2 This is a schematic diagram of the structure of a flexible pressure sensor with intrinsic zero temperature coefficient according to Embodiment 1 of the present invention.

[0025] Figure 3 This is a performance comparison of the porous carbon-based nanocomposite materials in the flexible pressure sensors of Embodiment 1, Comparative Example 1-1, and Comparative Example 1-2 of the present invention.

[0026] Figure 4 This is a performance comparison of the porous carbon-based nanocomposite materials in the flexible pressure sensors of Embodiment 2, Comparative Example 2-1, and Comparative Example 2-2 of the present invention. Detailed Implementation

[0027] To make the technical means, creative features, objectives and effects of the present invention easy to understand, the following embodiments, in conjunction with the accompanying drawings, specifically illustrate a porous carbon-based nanocomposite material with intrinsic zero temperature coefficient, its preparation method, and a flexible pressure sensor with intrinsic zero temperature coefficient.

[0028] Example 1: Preparation of a single-layer porous carbon-based nanocomposite material with intrinsic zero temperature coefficient based on the conductive filler mass fraction control method.

[0029] Figure 1 This is a flowchart illustrating the preparation process of the porous carbon-based nanocomposite material with intrinsic zero temperature coefficient according to Example 1 of the present invention.

[0030] like Figure 1 As shown, this embodiment provides a method for preparing a single-layer porous carbon-based nanocomposite material with intrinsic zero temperature coefficient, including the following steps:

[0031] S10, prepare a homogenized mixture of PDMS prepolymer, curing agent, carbon black, carbon nanotubes and foaming agent, the specific operation is as follows:

[0032] Mix 10g of PDMS prepolymer with 1g of curing agent, add 0.5g of a mixture of carbon black and carbon nanotubes, and then add 0.5g of foaming agent NaHCO3. Homogenize the mixture by magnetic stirring at 500rpm for 10min at 25℃.

[0033] in:

[0034] (1) The system of PDMS prepolymer and curing agent is Dow Corning 184 (SYLGARD®184), that is, the PDMS prepolymer is vinyl-terminated polydimethylsiloxane and the curing agent is polymethylhydrosiloxane, specifically a mixture of dimethyl-methylhydrosiloxane copolymer and platinum catalyst.

[0035] (2) The average particle size of carbon black is 100nm~200nm, and the specific surface area is 42m². 2 / g~48m 2 / g.

[0036] (3) The outer diameter of carbon nanotubes is 3nm~15nm and the length is 1.5μm~3μm.

[0037] S20, under continuous stirring, add 0.5g of hydrochloric acid (analytical grade) with a mass fraction of 36.0%~38.0% to the homogenized mixture obtained in step S10 to react with the foaming agent to generate bubbles, and continue stirring for 2 minutes until the bubbles are uniform to obtain a foamed mixture.

[0038] S30: Pour the foamed mixture prepared in step S20 onto a glass substrate, coat it into a film with a scraper with a gap of 0.5 mm, heat and cure it at 100°C for 1 hour, and demold to obtain a single-layer porous carbon-based nanocomposite material.

[0039] Subsequently, the porous carbon-based nanocomposite material was cut into dimensions of 1.5cm×1.5cm×0.5mm. Conductive silver paste was coated on its upper and lower surfaces, and copper foil electrodes were attached. After welding leads, a flexible pressure sensor was assembled. The sensor was placed in an oven with an accuracy of ±0.5℃, and the relative change rate of resistance of the porous carbon-based nanocomposite material in the sensor was recorded synchronously in the full temperature range of 25℃ to 100℃ using a digital multimeter.

[0040] In this embodiment, the addition ratio of carbon black and carbon nanotubes in step S10 is adjusted by controlling the mass fraction of conductive filler, so that the relative resistance change rate of the porous carbon-based nanocomposite material in the flexible pressure sensor remains within ±2% across the entire temperature range of 25℃ to 100℃. The determined mass ratio of carbon black to carbon nanotubes is 1:9, i.e., 0.05g of carbon black and 0.45g of carbon nanotubes. The resulting single-layer porous carbon-based nanocomposite material is denoted as an intrinsically zero-temperature coefficient porous carbon-based nanocomposite material (in this embodiment, the criterion for zero-temperature coefficient characteristics is defined as the relative resistance change rate remaining within ±2% across the entire temperature range of 25℃ to 100℃). Its porosity is measured to be 0.2.

[0041] Figure 2 This is a schematic diagram of the structure of a flexible pressure sensor with intrinsic zero temperature coefficient according to Embodiment 1 of the present invention.

[0042] like Figure 2 As shown, this embodiment also provides a flexible pressure sensor with an intrinsic zero temperature coefficient, which is the flexible pressure sensor with a carbon black and carbon nanotube mass ratio of 1:9. It uses a porous carbon-based nanocomposite material with an intrinsic zero temperature coefficient as the sensitive layer.

[0043] Comparative Example 1-1: Preparation of porous carbon-based nanocomposites when the conductive filler ratio deviates.

[0044] This comparative example is largely the same as Example 1, except that the mass of both carbon black and carbon nanotubes used in the preparation process is 0.25g, that is, the mass ratio of the two is 1:1.

[0045] Comparative Examples 1-2: Preparation of porous carbon-based nanocomposites when the conductive filler ratio deviates.

[0046] This comparative example is largely the same as Example 1, except that the mass of carbon black and carbon nanotubes used in the preparation process is 0.1g and 0.4g, respectively, that is, the mass ratio of the two is 1:4.

[0047] Figure 3This is a performance comparison of the porous carbon-based nanocomposite materials in the flexible pressure sensors of Embodiment 1, Comparative Example 1-1, and Comparative Example 1-2 of the present invention.

[0048] like Figure 3 As shown:

[0049] (1) The porous carbon-based nanocomposite material in the flexible pressure sensor prepared in Comparative Example 1-1 has a relative resistance change rate of up to 28.8% at 100℃, exhibiting extremely strong positive temperature coefficient behavior, far exceeding the judgment standard of ±2%.

[0050] (2) The porous carbon-based nanocomposite material in the flexible pressure sensor prepared in Comparative Example 1-2 has a relative resistance change rate of 6.68% at 100℃, which significantly exceeds the judgment standard of ±2%, and exhibits positive temperature coefficient behavior, but is closer to the zero temperature coefficient window than Comparative Example 1.

[0051] (3) The porous carbon-based nanocomposite material with intrinsic zero temperature coefficient in the flexible pressure sensor prepared in Example 1 has a relative resistance change rate of -0.46% to 1.03% in the full temperature range of 25℃ to 100℃, which fully meets the zero temperature coefficient judgment criteria and is the optimal solution for the control of conductive filler ratio in this example.

[0052] Example 2: Preparation of a single-layer porous carbon-based nanocomposite material with intrinsic zero temperature coefficient based on the porosity control method.

[0053] This embodiment provides a method for preparing a single-layer porous carbon-based nanocomposite material with intrinsic zero temperature coefficient, which is largely similar to that of Embodiment 1. The difference is that the amount of carbon black added in step S10 is fixed at 0.1g, and the amount of carbon nanotubes added is fixed at 0.4g, that is, the mass ratio of the two is 1:4; the amount of foaming agent NaHCO3 and hydrochloric acid (analytical grade) with a mass fraction of 36.0%~38.0% in step S30 is not fixed.

[0054] The method for testing the relative change rate of resistance of the prepared porous carbon-based nanocomposite material in this embodiment is the same as that in Example 1 (assembling it into a flexible pressure sensor), and will not be repeated here.

[0055] In this embodiment, by adjusting the amounts of foaming agent NaHCO3 in step S10 and hydrochloric acid (analytical grade) with a mass fraction of 36.0%~38.0% in step S30 based on the porosity control method, the relative change rate of the resistance of the porous carbon-based nanocomposite material in the flexible pressure sensor is kept within ±2% over the entire temperature range from 25℃ to 100℃. The determined feeding mass of foaming agent NaHCO3 is 1.5g, and the corresponding feeding amount of hydrochloric acid is 1.5g. The resulting single-layer porous carbon-based nanocomposite material is the intrinsically zero temperature coefficient porous carbon-based nanocomposite material in this embodiment. Its porosity was measured to be 0.5.

[0056] This embodiment also provides a flexible pressure sensor with an intrinsic zero temperature coefficient, which is assembled in the same way as in Embodiment 1, and will not be repeated here.

[0057] Comparative Example 2-1: Preparation of porous carbon-based nanocomposites when porosity deviates.

[0058] This comparative example is largely the same as Example 2, except that the amount of foaming agent NaHCO3 used in the preparation process is 0.5g (the amount of hydrochloric acid in step S30 is also adjusted accordingly), and the porosity of the composite material is 0.2. The remaining steps are exactly the same as in Example 2.

[0059] Comparative Example 2-2: Preparation of porous carbon-based nanocomposites when porosity deviates.

[0060] This comparative example is largely the same as Example 2, except that the amount of foaming agent NaHCO3 used in the preparation process is 1.0g (the amount of hydrochloric acid in step S30 is also adjusted accordingly), and the porosity of the composite material is 0.4. The remaining steps are exactly the same as in Example 2.

[0061] Figure 4 This is a performance comparison of the porous carbon-based nanocomposite materials in the flexible pressure sensors of Embodiment 2, Comparative Example 2-1, and Comparative Example 2-2 of the present invention.

[0062] like Figure 4 As shown:

[0063] (1) The porous carbon-based nanocomposite material in the flexible pressure sensor prepared in Comparative Example 2-1 exhibits a relative resistance change rate of 6.68% at 100°C, far exceeding the ±2% criterion. Furthermore, in conjunction with Example 1 and... Figure 3 It can be seen that the porous carbon-based nanocomposite material in the flexible pressure sensor of Comparative Example 2-1 simultaneously coincides with the ratio and porosity of Example 1, further confirming that deviation from the preferred combination parameters will lead to temperature drift.

[0064] (2) The porous carbon-based nanocomposite material in the flexible pressure sensor prepared in Comparative Example 2-2 has a relative resistance change rate of 2.65% at 100℃, which is slightly higher than the upper limit of ±2% and very close to the equilibrium point.

[0065] (3) The porous carbon-based nanocomposite material with intrinsic zero temperature coefficient in the flexible pressure sensor prepared in Example 1 has a relative resistance change rate between -1.26% and -0.33% in the full temperature range of 25℃ to 100℃, which fully meets the zero temperature coefficient criterion and is the optimal solution for the porosity control method in this example.

[0066] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a porous carbon-based nanocomposite material with intrinsic zero temperature coefficient, characterized in that, Includes the following steps: S10, prepare a homogenized mixture of PDMS prepolymer, curing agent, carbon black, carbon nanotubes and foaming agent; S20, under continuous stirring, hydrochloric acid is added to the mixture to react with the foaming agent to generate bubbles, and the mixture is stirred until the bubbles are uniform to obtain a foamed mixture; S30, after the foamed mixture is formed into a film, it is heated and cured at 90℃~110℃ for 45min~1h to obtain a single-layer porous carbon-based nanocomposite material with intrinsic zero temperature coefficient. In particular, by synergistically controlling the amount of carbon black, carbon nanotubes and foaming agent added in step S10, the negative temperature coefficient effect and positive temperature coefficient effect of the porous carbon-based nanocomposite material with intrinsic zero temperature coefficient in step S30 are ultimately mutually canceled in the range of 25℃~100℃, so that the absolute value of its relative change rate of resistance is ≤2%.

2. The method for preparing porous carbon-based nanocomposite materials with intrinsic zero temperature coefficient according to claim 1, characterized in that: in, In step S10, the PDMS prepolymer is vinyl-terminated polydimethylsiloxane, and the curing agent is polymethylhydrosiloxane. The mass ratio of the PDMS prepolymer to the curing agent is 10:

1.

3. The method for preparing porous carbon-based nanocomposite materials with intrinsic zero temperature coefficient according to claim 1, characterized in that: in, In step S10, the average particle diameter of the carbon black is 100 nm to 200 nm, and the specific surface area is 42 m 2 / g to 48 m 2 / g.

4. The method for preparing porous carbon-based nanocomposite materials with intrinsic zero temperature coefficient according to claim 1, characterized in that: in, In step S10, the outer diameter of the carbon nanotube is 3nm~15nm and the length is 1.5μm~3μm.

5. The method for preparing porous carbon-based nanocomposite materials with intrinsic zero temperature coefficient according to claim 1, characterized in that: in, In step S10, the foaming agent includes sodium bicarbonate.

6. The method for preparing porous carbon-based nanocomposite materials with intrinsic zero temperature coefficient according to claim 1, characterized in that: in, The method for synergistically controlling the amount of carbon black, carbon nanotubes, and foaming agent added in step S10 is: based on the conductive filler mass fraction control method or based on the porosity control method. The conductive filler mass fraction control method is as follows: after fixing the mass of the PDMS prepolymer, the curing agent, and the foaming agent, the sum of the masses of the carbon black and the carbon nanotubes is fixed, and the mass ratio of the carbon black to the carbon nanotubes is adjusted so that the absolute value of the relative change rate of the resistivity of the porous carbon-based nanocomposite material with intrinsic zero temperature coefficient is ≤2%. The porosity control method involves fixing the total mass of the PDMS prepolymer, the curing agent, the carbon black, and the carbon nanotubes, and then adjusting the mass of the foaming agent so that the absolute value of the relative change rate of the resistivity of the porous carbon-based nanocomposite material with an intrinsic zero temperature coefficient is ≤2%.

7. The method for preparing porous carbon-based nanocomposite materials with intrinsic zero temperature coefficient according to claim 6, characterized in that: in, In the method based on the mass fraction control of conductive fillers: When the foaming agent is sodium bicarbonate, the ratio of the mass m1 of the carbon black, the mass m2 of the carbon nanotubes, the sum of the masses m3 of the PDMS prepolymer and the curing agent, and the mass m4 of the foaming agent is 1:9:220:

10.

8. The method for preparing porous carbon-based nanocomposite materials with intrinsic zero temperature coefficient according to claim 6, characterized in that: in, In the porosity-based control method: When the foaming agent is sodium bicarbonate, the ratio of the mass m1 of the carbon black, the mass m2 of the carbon nanotubes, the sum of the masses m3 of the PDMS prepolymer and the curing agent, and the mass m4 of the foaming agent is 1:4:110:

15.

9. A porous carbon-based nanocomposite material with intrinsic zero temperature coefficient, characterized in that, It is prepared by the method for preparing porous carbon-based nanocomposite material with intrinsic zero temperature coefficient according to any one of claims 1 to 8.

10. A flexible pressure sensor with intrinsic zero temperature coefficient, characterized in that, The porous carbon-based nanocomposite material with intrinsic zero temperature coefficient as described in claim 9 was used as the sensing layer. The sensitive layer surface is fixed with copper foil electrodes and soldered with leads.

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