A humidity sensor based on plasma processing and its preparation method

Abstract

The present invention relates to the field of sensor technology, and in particular to a humidity sensor based on plasma treatment and a preparation method thereof. The humidity sensor comprises an electrode sheet, wherein the electrode sheet comprises a polydimethylsiloxane film, a laser-induced graphene layer, and a graphene oxide layer arranged in sequence; contact sites are respectively provided at two end points of the laser-induced graphene layer; two wires respectively connect the two contact sites; and a polyvinylidene fluoride film is attached to the top layer of the electrode sheet as an encapsulation layer. The preparation method obtains the electrode sheet by plasma jet oxidation treatment of the polydimethylsiloxane-laser-induced graphene-graphene oxide layer. The plasma jet oxidation treatment enriches the graphene surface with a large number of oxygen-containing functional groups, making the graphene have excellent hydrophilicity and adsorbing more water molecules. As the sensitive layer of the humidity sensor, the graphene has better performance, greater stability, and higher sensitivity.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a humidity sensor based on plasma processing and a preparation method thereof. Background Art

[0002] A humidity sensor is an electronic device that measures ambient humidity and plays an important role in industries such as industry, agriculture, and environmental testing. The core component of a humidity sensor is a sensitive material that can convert humidity into other testable signals. Currently, semiconductor oxides, high molecular polymers, and related composite materials are commonly used as humidity-sensitive materials. However, these sensors generally suffer from problems such as a small detection range and low sensitivity. Graphene oxide, a derivative of graphene, has a large specific surface area and abundant oxygen-containing functional groups, which can connect to water molecules through hydrogen bonds. Therefore, graphene oxide is very suitable as a sensitive material for a humidity sensor. However, the preparation process of existing graphene oxide humidity sensors mostly uses chemical methods, which cause great environmental pollution and easily affect the stability of the humidity sensor's carrier. As a result, the measurement accuracy of the humidity sensor is low. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the first object of the present invention is to provide a method for preparing a humidity sensor based on plasma processing; the second object of the present invention is to provide a humidity sensor based on plasma processing.

[0004] In order to achieve the first purpose, the technical solution adopted by the present invention is:

[0005] A method for preparing a humidity sensor based on plasma processing comprises the following steps:

[0006] S100, attaching a polyimide (PI) film to a glass substrate, and using a laser to induce graphene interdigitated electrodes to form a laser-induced graphene (LIG)-PI layer;

[0007] S200, peeling LIG-PI from the glass substrate and attaching it to the mold;

[0008] S300, mixing a polydimethylsiloxane (PDMS) solution with a curing agent to prepare a first solution;

[0009] S400, pouring the first solution into a mold and drying it to obtain a PDMS-LIG-PI layer;

[0010] S500, taking the PDMS-LIG-PI layer out of the mold, removing the PI layer, and obtaining a PDMS-LIG layer;

[0011] S600, coating a graphene oxide (GO) aqueous solution on the top layer of the graphene interdigitated electrode and drying to obtain a PDMS-LIG-GO layer;

[0012] S700, after treating the PDMS-LIG-GO layer by plasma jet oxidation, obtaining an electrode sheet;

[0013] The gas used in the plasma jet oxidation treatment is a mixture of argon, ethanol and oxygen. A mass flow meter is used to control the mixing ratio of the three gases during the plasma treatment process.

[0014] The flow rate of argon is 4000~6000 standard cubic centimeter per minute (SCCM), the flow rate of ethanol is 20SCCM~40SCCM, and the flow rate of oxygen is 2SCCM~4SCCM;

[0015] S800: Attach a polyvinylidene fluoride (PVDF) film to the top layer of the electrode sheet to obtain a humidity sensor.

[0016] Furthermore, the mass concentration of PDMS in S300 is 20% to 70%.

[0017] Furthermore, in S300 , the mass ratio of the PDMS solution to the curing agent is 10:1 to 9:1.

[0018] Furthermore, the curing agent in S300 is tetravinyltetramethylsilane or a silane coupling agent.

[0019] Furthermore, the drying temperature in S400 is 80° C. to 100° C., and the drying time is 90 min to 120 min.

[0020] Furthermore, the concentration of the graphene oxide aqueous solution in S600 is 2 mg / ml to 5 mg / ml.

[0021] Furthermore, the jet device used in the plasma jet oxidation in S700 includes:

[0022] an oxygen branch, the oxygen branch comprising an oxygen storage tank, a first mass flow meter, and a plasma generator connected in sequence through a pipeline;

[0023] a first argon gas branch, the first argon gas branch comprising an argon gas storage tank, a second mass flow meter, and a plasma generator connected in sequence through a pipeline;

[0024] a second argon branch, the second argon branch comprising an ethanol evaporator and a third mass flow meter connected in sequence through a pipeline, the ethanol evaporator and the third mass flow meter being connected in parallel with the second mass flow meter;

[0025] A power drive unit is connected to the plasma generator.

[0026] Furthermore, the plasma generator includes a jet head, an annular ground electrode, an annular high-voltage electrode and a pneumatic joint which are sequentially connected from bottom to top.

[0027] Furthermore, the pulse rising edge of the power drive unit is 20ns to 70ns, the pulse amplitude is 5kV to 9kV, the pulse frequency is 10kHz to 25kHz, and the pulse width is 10μs to 25μs.

[0028] In order to achieve the second purpose, the technical solution adopted by the present invention is:

[0029] A humidity sensor based on plasma processing, wherein the humidity sensor is prepared using any of the above preparation methods, comprising:

[0030] An electrode sheet, comprising a PDMS film, a LIG structure layer, and a GO layer arranged sequentially from bottom to top;

[0031] Wherein, contact sites are provided at two end points of the LIG structure layer;

[0032] Two wires, the two wires are respectively connected to the two contact points;

[0033] Encapsulation film: PVDF film is attached to the top of the GO layer as an encapsulation layer.

[0034] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0035] This invention utilizes plasma technology to treat graphene oxide to form the sensitive layer of a humidity sensor. Plasma jet oxidation enriches the graphene surface with oxygen-containing functional groups, making it highly hydrophilic and allowing it to absorb more water molecules. This results in improved performance, greater stability, and higher sensitivity as the sensitive layer of a humidity sensor. Plasma jet modification reduces the use of chemicals and produces no waste, resulting in a pollution-free and environmentally friendly process. Furthermore, the plasma jet oxidation method for preparing sensitive materials is cost-effective and facilitates large-scale production.

[0036] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 This is a flow chart of the preparation of a humidity sensor based on plasma processing provided in Example 1 of the present invention.

[0039] Figure 2 This is a schematic structural diagram of a humidity sensor based on plasma processing provided in Example 1 of the present invention.

[0040] Figure 3 It is a schematic structural diagram of the jet device provided in Example 1 of the present invention.

[0041] Figure 4 This is a statistical diagram showing how the sensitivity of the humidity sensor provided by Example 1 of the present invention changes with processing time.

[0042] Figure 5 This is a graph of a repeatability performance test of a humidity sensor based on plasma treatment provided in Experimental Example 1 of the present invention.

[0043] Figure 6 This is a response time curve of a humidity sensor based on plasma processing provided in Experimental Example 2 of the present invention.

[0044] Figure 7 This is a dynamic response curve diagram of capacitance of a humidity sensor based on plasma treatment provided in Experimental Example 2 of the present invention.

[0045] Figure 8 This is a capacitance response curve of a humidity sensor based on plasma treatment as humidity changes, provided in Experimental Example 2 of the present invention.

[0046] Reference numerals:

[0047] 1. PDMS film; 2. LIG structural layer; 3. Contact sites; 4. Wires; 5. GO layer; 6. Encapsulation layer;

[0048] 711. Oxygen storage tank; 712. First mass flow meter; 713. Plasma generator; 7131. Jet head; 7132. Annular ground electrode; 7133. Annular high-voltage electrode; 7134. Pneumatic connector; 721. Argon storage tank; 722. Second mass flow meter; 731. Ethanol evaporator; 732. Third mass flow meter; 741. Power drive unit. DETAILED DESCRIPTION

[0049] To make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0050] In the following examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all available from commercial sources unless otherwise specified.

[0051] A method for preparing a humidity sensor based on plasma treatment, the preparation process is as follows Figure 1 As shown, the following steps are included:

[0052] S100, attaching the PI film to a glass substrate, and using a laser to induce graphene interdigitated electrodes to form a LIG-PI layer;

[0053] S200, peeling LIG-PI from the glass substrate and attaching it to the mold;

[0054] S300, mixing the PDMS solution with a curing agent to prepare a first solution;

[0055] S400, pouring the first solution into a mold and drying it to obtain a PDMS-LIG-PI layer;

[0056] S500, taking the PDMS-LIG-PI layer out of the mold, removing the PI layer, and obtaining a PDMS-LIG layer;

[0057] S600, coating a GO aqueous solution on the top layer of the graphene interdigitated electrode and drying to obtain a PDMS-LIG-GO layer;

[0058] S700, after treating the PDMS-LIG-GO layer by plasma jet oxidation, obtaining an electrode sheet;

[0059] The gas used in the plasma jet oxidation treatment is a mixture of argon, ethanol and oxygen. A mass flow meter is used to control the mixing ratio of the three gases during the plasma treatment process.

[0060] The flow rate of argon is 4000 SCCM~6000 SCCM, the flow rate of ethanol is 20 SCCM~40 SCCM, and the flow rate of oxygen is 2 SCCM~4 SCCM;

[0061] S800 , attaching PVDF to the top layer of the electrode sheet to obtain a humidity sensor.

[0062] A humidity sensor based on plasma processing, the humidity sensor is prepared using the above preparation method, such as Figure 2 As shown, the humidity sensor includes:

[0063] An electrode sheet, comprising a PDMS film 1, a LIG structure layer 2, and a GO layer 5 arranged sequentially from bottom to top;

[0064] Wherein, contact sites 3 are provided at two end points of the LIG structure layer 2;

[0065] Two wires 4, the two wires 4 are respectively connected to the two contact points 3;

[0066] Encapsulation film: PVDF film is attached to the top of GO layer 5 as encapsulation layer 6.

[0067] Example 1

[0068] According to Figure 1 The flow chart shown is for preparing electrode sheets.

[0069] The first solution was prepared as follows: the PDMS solution and the curing agent were mixed at a mass ratio of 10:1, stirred at 25° C. for 5 minutes, and allowed to stand for 20 minutes until the bubbles completely disappeared, to obtain the first solution;

[0070] The concentration of the PDMS solution can be flexibly selected according to the requirements of the humidity sensor. For example, the mass concentration of the PDMS solution can be 20%, 30%, 50%, or 70%, but is not limited to the listed concentrations.

[0071] The mass ratio of PDMS solution to curing agent can be selected from 9:1, 9.5:1, and 10:1, but is not limited to the above three mass ratios;

[0072] During the treatment of the solution after the PDMS solution and the curing agent are mixed, the time can be freely controlled according to the mixing state of the PDMS solution and the curing agent to achieve the purpose of uniformly mixing the PDMS solution and the curing agent. When the bubbles in the uniformly mixed first solution disappear, the treatment can be stopped and allowed to stand. The purpose of standing to remove bubbles is to improve the transfer quality of LIG to the PDMS film 1.

[0073] The curing agent is tetravinyltetramethylsilane; the curing agent is tetravinyltetramethylsilane, and can also be a silane coupling agent.

[0074] The drying conditions in S400 are: drying in a drying oven at 85°C for 120 min; the size of the mold is 27×27×2 mm 3 ; Drying evaporates the solvent in the PDMS solution, and the remaining PDMS solute forms a PDMS film 1, the size of the film is 27×27 mm 2 , thickness is 2mm; PI film is cut from PI film tape with a thickness of 0.08mm, and the size of PI film is 25×25mm 2 , thickness is 0.08mm.

[0075] The drying conditions in S400 may also be selected to be performed in ovens at other temperatures, and the drying time may be adjusted accordingly. For example, the drying oven may be used for drying for 90 minutes at 95°C, or for drying for 110 minutes at 80°C. The temperature of the drying oven is selected to ensure drying and the transfer quality of the LIG onto the PDMS film layer 1. The drying temperature and drying time are not limited to the listed drying temperatures and drying times.

[0076] The process of laser-induced graphene interdigitated electrodes is as follows:

[0077] 1. Introduce the pattern of graphene interdigitated electrodes to be formed into the CO2 laser marking machine;

[0078] 2. Set the printing parameters. The printing parameters include the line width of the graphene interdigital electrode is 0.5mm, the length is 9mm, the interdigital spacing of the graphene interdigital electrode to be formed is 0.5mm, the height is 15mm, the number of interdigits is 10, and the electrode area of ​​the graphene interdigital electrode to be formed is 2×2mm 2 ;

[0079] 3. Set the working parameters of the CO2 laser marking machine. The working parameters include setting the laser wavelength of the CO2 laser marking machine to 10.64μm, the laser repetition frequency to 5kHz, the laser power to 3w, and the scanning speed to 400mm / s.

[0080] 4. Start the CO2 laser marking machine and use laser to induce graphene interdigitated electrodes on the top layer of the polyimide film.

[0081] Experimenters can design parameters such as line width, length, interdigital spacing, height, interdigital quantity, and electrode area of ​​the graphene interdigital electrode according to the actual requirements of the humidity sensor. The present invention does not impose specific restrictions on the parameters of the graphene interdigital electrode.

[0082] It should be noted that the experimenter can adjust the working parameters of the CO2 laser marking machine according to the actual working environment, and the present invention does not impose any specific restrictions on the working parameters of the CO2 laser marking machine.

[0083] The concentration of the graphene oxide aqueous solution in S600 is 2 mg / ml. Other concentrations of graphene aqueous solutions may also be selected, such as 3 mg / ml, 4 mg / ml, and 5 mg / ml, but are not limited to the above-listed concentrations of the graphene oxide aqueous solution.

[0084] like Figure 3 As shown, the jet device used for plasma jet oxidation in S700 includes:

[0085] An oxygen branch, comprising an oxygen storage tank 711, a first mass flow meter 712, and a plasma generator 713 connected in sequence through pipelines;

[0086] A first argon gas branch, comprising an argon gas storage tank 721, a second mass flow meter 722, and a plasma generator 713 connected in sequence through a pipeline;

[0087] The second argon branch includes an ethanol evaporator 731 and a third mass flow meter 732 connected in sequence through pipelines. The ethanol evaporator 731 and the third mass flow meter 732 are connected in parallel with the second mass flow meter 722; the ethanol evaporator 731 is connected in parallel to the argon branch. The argon storage tank 721 can be opened before ethanol is introduced, and argon is used to discharge the air in the pipeline to prevent the composition of the air from affecting the release of plasma from the plasma generator 713.

[0088] After the ethanol evaporator 731 is turned on, the argon gas in the pipeline passes through the ethanol evaporator 731 , the argon gas increases the volatilization amount of the ethanol, and brings the volatilized ethanol into the position of the plasma generator 713 .

[0089] The power driving unit 741 is connected to the plasma generator 713 .

[0090] The plasma generator 713 includes a jet head 7131, an annular ground electrode 7132, an annular high-voltage electrode 7133 and a pneumatic joint 7134, which are connected in sequence from bottom to top. The jet head 7131 is installed at the bottom of the annular ground electrode 7132. The annular ground electrode 7132 and the annular high-voltage electrode 7133 are connected through a dielectric tube. The annular high-voltage electrode 7133 and the pneumatic joint 7134 are connected through a dielectric tube. The output ends of the argon storage tank 721, the oxygen storage tank 711 and the ethanol evaporator 731 are connected to the top of the pneumatic joint 7134. The jet head 7131 is provided to facilitate the collection of plasma generated by the plasma generator 713. The annular high-voltage electrode 7133 is located at the upstream end of the airflow and has a width of 1c. m, the annular ground electrode 7132 is located at the downstream end of the airflow, with a width of 0.5 cm, the distance between the annular high-voltage electrode 7133 and the annular ground electrode 7132 is 1 cm and the conductive materials are both copper, the annular high-voltage electrode 7133 and the annular ground electrode 7132 are connected to the power drive unit 741, and its pulse rising edge is 50 ns, the pulse amplitude is 7 kV, the pulse frequency is 15 kHz, and the pulse width is 10 μs, which provides excitation for the plasma generator 713 to generate Ar, EtOH, and O2 plasma jets.

[0091] When the PDMS-LIG-GO layer is treated with plasma, the argon flow rate is controlled to 5000 SCCM using the second mass flow meter 722 , the ethanol flow rate is controlled to 30 SCCM using the third mass flow meter 732 , and the oxygen flow rate is controlled to 4 SCCM using the first mass flow meter 712 ;

[0092] Set the pulse rising edge of the power drive unit 741 to 50ns, the pulse amplitude to 7kV, the pulse frequency to 15kHz, and the pulse width to 10μs;

[0093] The top layer of the graphene interdigitated electrode coated with graphene oxide aqueous solution was placed 5 mm away from the bottom of the PDMS and treated in an atmospheric environment at 25°C for 3 minutes to produce a plasma-treated PDMS-LIG-GO layer.

[0094] When using the plasma-treated PDMS-LIG-GO layer to make a humidity sensor, a conductive silver paste is applied to the graphene interdigitated electrodes of the plasma-treated PDMS-LIG-GO structure to form two contact sites 3. In step S800, two wires 4 are provided and connected to the two contact sites 3 respectively. A PVDF film is attached to the GO layer 5 as an encapsulation layer 6 to obtain a humidity sensor.

[0095] The time for treating the PDMS-LIG-GO layer with plasma jet was set to 0 min, 1 min, 2 min, and 3 min, and the sensitivity of the humidity sensor after the corresponding treatment time was tested. The test results are shown in Figure 2. Figure 4 shown.

[0096] When the treatment time is 0 min, the sensitivity of the humidity sensor is 10.594; when the treatment time is 1 min, the sensitivity of the humidity sensor is 18.486; after that, the treatment time is increased to 70.335 and 113.17 when the treatment time is 2 min and 3 min respectively.

[0097] Specifically, the humidity sensor needs to have good stability and sensitivity. The sensitivity of the humidity sensor is defined as Sensitivity means the change in the electrical parameters of the humidity sensor when the relative humidity changes by 1%RH within the humidity range. It is used to indicate the sensitivity of the humidity sensor's humidity characteristic to humidity. is the capacitance change, that is, the difference between the capacitance value at the current relative humidity and the capacitance value at the initial relative humidity; is the relative humidity change value, that is, the difference between the current relative humidity and the initial relative humidity.

[0098] In the following experimental example, a humidity sensor based on plasma treatment was prepared. The PDMS-LIG-GO layer was treated with a plasma jet for 3 minutes, and the experimental process used existing conventional experimental methods.

[0099] Experimental Example 1

[0100] like Figure 5 As shown, Figure 5 This is a repeatability experiment of the humidity sensor to verify the stability of the humidity sensor under different relative humidity. The horizontal axis is the number of cycles and the vertical axis is the capacitance value. The humidity sensor is placed from a relative humidity environment of 20% to a relative humidity environment of 80%, and the capacitance value of the humidity sensor is tested. After the humidity sensor responds, it is placed back to a relative humidity environment of 20% and the capacitance value of the humidity sensor is tested. This cycle is repeated three times. After three cycles, the capacitance value of the humidity sensor at the same humidity remains basically unchanged, proving that the humidity sensor has good repeatability and good stability.

[0101] Experimental Example 2

[0102] like Figure 6 As shown in FIG, the static response diagram of the humidity sensor is shown, where the horizontal axis is time and the vertical axis is capacitance value.

[0103] like Figure 7 As shown in the figure, the dynamic response diagram of the humidity sensor is shown, with the horizontal axis being time and the vertical axis being capacitance value. Figure 7 Shows the response and recovery time of the humidity sensor to different humidity levels. Figure 7 This shows that the humidity sensor has good linearity, fast response and recovery speed within the humidity range;

[0104] like Figure 8 As shown in FIG, the performance curve of the humidity sensor is shown, where the horizontal axis is relative humidity and the vertical axis is capacitance value. The figure reflects the excellent characteristics of the humidity sensor within the humidity range.

[0105] In summary, the preparation method of a humidity sensor based on plasma treatment provided by the present invention is simple to operate, the preparation process takes a short time, the material cost is low, and it does not require complex processing technology and harsh operating environment. It is suitable for large-scale production. This preparation method can not only overcome the problems of large environmental pollution and unstable performance of humidity sensors caused by the wet chemical method for preparing graphene oxide, but also help to break through the bottleneck of the current capacitive sensing detection technology of trace water content in transformer oil, which is of great significance to the precise operation and maintenance of power transformers.

[0106] The present invention provides a plasma-processed humidity sensor with a simple structure. It utilizes a flexible PDMS film 1 as a substrate and a PVDF film as an encapsulation layer 6. This sensor exhibits high flexibility and mechanical strength, making it adaptable to complex operating environments. Furthermore, the sensor boasts high sensitivity and accuracy, a wide detection range, excellent stability, and a short response time, promising broad application prospects.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing a humidity sensor based on plasma treatment, characterized in that: The steps include: S100, attaching a polyimide film to a glass substrate, and using laser to induce graphene interdigitated electrodes to form a laser-induced graphene-polyimide layer; S200, peeling the laser-induced graphene-polyimide layer from the glass substrate and attaching it to the mold; S300, mixing a polydimethylsiloxane solution with a curing agent to prepare a first solution; S400, pouring the first solution into a mold and drying it to obtain a polydimethylsiloxane-laser induced graphene-polyimide layer; S500, taking the polydimethylsiloxane-laser induced graphene-polyimide layer out of the mold, removing the polyimide layer, and obtaining a polydimethylsiloxane-laser induced graphene layer; S600, coating a graphene oxide aqueous solution on the top layer of the graphene interdigitated electrode and drying to obtain a polydimethylsiloxane-laser induced graphene-graphene oxide layer; S700, treating the polydimethylsiloxane-laser-induced graphene-graphene oxide layer by plasma jet oxidation to obtain an electrode sheet; The gas used in the plasma jet oxidation treatment is a mixture of argon, ethanol and oxygen. A mass flow meter is used to control the mixing ratio of the three gases during the plasma treatment process. Among them, the flow rate of argon is 4000~6000 volume flow units, the flow rate of ethanol is 20~40 volume flow units, and the flow rate of oxygen is 2~4 volume flow units; The jet device used in plasma jet oxidation includes: an oxygen branch, the oxygen branch comprising an oxygen storage tank, a first mass flow meter, and a plasma generator connected in sequence through a pipeline; a first argon gas branch, the first argon gas branch comprising an argon gas storage tank, a second mass flow meter, and a plasma generator connected in sequence through a pipeline; a second argon branch, the second argon branch comprising an ethanol evaporator and a third mass flow meter connected in sequence through a pipeline, the ethanol evaporator and the third mass flow meter being connected in parallel with the second mass flow meter; A power drive unit connected to the plasma generator; The plasma generator comprises a jet head, an annular ground electrode, an annular high-voltage electrode and a pneumatic joint connected in sequence from bottom to top; S800, attaching the polyvinylidene difluoride film to the top layer of the electrode sheet to obtain a humidity sensor.

2. The method for preparing a humidity sensor based on plasma treatment according to claim 1, wherein: The mass concentration of the polydimethylsiloxane solution in S300 is 20% to 70%.

3. The method for preparing a humidity sensor based on plasma treatment according to claim 1, wherein: The mass ratio of the polydimethylsiloxane solution to the curing agent in S300 is 10:1 to 9:

1.

4. The method for preparing a humidity sensor based on plasma treatment according to claim 1, wherein: The curing agent in S300 is tetravinyltetramethylsilane or silane coupling agent.

5. The method for preparing a humidity sensor based on plasma processing according to claim 1, wherein: The drying temperature in S400 is 80° C. to 100° C., and the drying time is 90 min to 120 min.

6. The method for preparing a humidity sensor based on plasma processing according to claim 1, wherein: The concentration of the graphene oxide aqueous solution in S600 is 2 mg / ml to 5 mg / ml.

7. The method for preparing a humidity sensor based on plasma processing according to claim 1, wherein: The power drive unit has a pulse rising edge of 20ns to 70ns, a pulse amplitude of 5kV to 9kV, a pulse frequency of 10kHz to 25kHz, and a pulse width of 10μs to 25μs.

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