CN112985470B - Flexible capacitance sensor based on silver nanowire material and preparation method - Google Patents
Flexible capacitance sensor based on silver nanowire material and preparation method Download PDFInfo
- Publication number
- CN112985470B CN112985470B CN202110333939.XA CN202110333939A CN112985470B CN 112985470 B CN112985470 B CN 112985470B CN 202110333939 A CN202110333939 A CN 202110333939A CN 112985470 B CN112985470 B CN 112985470B
- Authority
- CN
- China
- Prior art keywords
- film
- polyurethane
- polyvinylidene fluoride
- silver nanowire
- solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
- G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
- G01D5/24—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying capacitance
- G01D5/2405—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying capacitance by varying dielectric
Abstract
The invention discloses a flexible capacitance sensor based on silver nanowire materials and a preparation method thereof, wherein the flexible capacitance sensor comprises a silver nanowire network with an aspect ratio of more than 800 as a capacitance electrode material, and also comprises a polyurethane/polyvinylidene fluoride polarized flexible film as a capacitance dielectric layer, the silver nanowire network and the polyurethane/polyvinylidene fluoride are combined to form a flexible film sensor, and the preparation method of the film sensor comprises the following steps: preparing silver nanowires with an aspect ratio of more than 800; preparing a polyurethane/polyvinylidene fluoride film; the silver nanowire is placed into absolute ethyl alcohol and dispersed, adhesive tapes are adhered to the periphery of the front side of the film to form grooves, silver nanowire solution is poured into the grooves, the rest ethanol is volatilized, the operation is repeated on the back side of the film, the adhesive tapes are torn off, the film is dried in the air, and electrodes are led out, so that the silver nanowire polyurethane/polyvinylidene fluoride flexible conductive film is obtained.
Description
Technical Field
The invention relates to a flexible capacitive sensor and a preparation method thereof, in particular to a flexible capacitive sensor based on silver nanowire materials and a preparation method thereof, and belongs to the technical field of sensors.
Background
The flexible sensor has the characteristics of light weight, flexibility, wearing, portability, implantation, high sensitivity and the like, and is widely applied to various fields. According to the current research results at home and abroad in recent decades, the development of the flexible sensor has greatly advanced, and particularly, the flexible sensor has many opportunities in the environment of continuous development of new materials and nanotechnology. A typical capacitive pressure sensor consists of a deformable dielectric material sandwiched between two flexible conductive electrodes, the thickness and area of which change under the application of pressure, resulting in a change in capacitance. However, the pure elastic dielectric material deforms very little under the action of pressure, resulting in reduced sensitivity, affecting the performance of the sensor.
The chinese patent of patent document cn201911328978.X discloses a method for manufacturing a capacitive sensor, which is composed of upper and lower electrode layers made of flexible conductive silicone rubber and an intermediate dielectric layer made of pure silicone rubber, and has different sensitivities by introducing surface microstructures with different roughness into the electrode layers and the dielectric layers, but the design of the microstructures can only maintain high sensitivity response under a smaller pressure, and the application range is limited.
The Chinese patent of patent document CN2019111300990.X discloses a multifunctional flexible sensor, a preparation method and application thereof, wherein the multifunctional flexible sensor comprises a bottom flexible substrate, a lower surface electrode, an intermediate dielectric layer, a conductive electrode, an upper surface electrode and a top flexible substrate from bottom to top. The surface of the flexible dielectric layer is provided with a microstructure bulge, one end of the upper surface electrode is connected with a lead-out electrode, the temperature, the distance and the stress are measured, and the flexibility of the metal electrode is reduced to a certain extent. The above flexible sensor also has the following drawbacks: (1) The flexible sensor can be bent, but the flexibility is insufficient, and the bending angle cannot be too large. (2) In the process of coating the electrode, the high-temperature sputtered metal particles have great damage to the film material, and in the later use process, the electrode of the sensor is easy to fall off (the response speed, sensitivity, linearity and other indexes of the sensor are insufficient).
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides the flexible capacitance sensor based on the silver nanowire material and the preparation method thereof, which have the technical characteristics of lower cost, more sensitive conduction, capability of eliminating the problem of high-temperature sputtering of the electrode, reduction of the influence of the electrode on a dielectric layer and the like.
In order to achieve the above purpose, the present invention is realized by the following technical scheme:
a flexible capacitance sensor based on silver nanowire materials comprises a silver nanowire network with an aspect ratio of more than 800 as a capacitance electrode material, and also comprises a polyurethane/polyvinylidene fluoride polarized flexible film as a capacitance dielectric layer, wherein the silver nanowire network and the polyurethane/polyvinylidene fluoride are combined to form the flexible film sensor.
A preparation method of a flexible film sensor based on silver nanowire materials comprises the following steps:
step 1): preparing silver nanowires with an aspect ratio of more than 800: dissolving polyvinylpyrrolidone with a molecular weight of 300000 in 100ml of ethylene glycol, adding copper chloride with a concentration of 3mmol/L and ferric nitrate with a concentration of 2mmol/L, heating to 170 ℃ and stirring for 1h, then dropwise adding silver nitrate alcohol solution with a concentration of 0.02g/ml, continuing to react for 2h, airing to room temperature in air after the reaction is finished, pouring the obtained grey green solution into a test tube, washing with absolute ethyl alcohol and centrifuging for 5 times to obtain pure silver nanowires, and uniformly dispersing the silver nanowires in the ethanol solution for later use;
step 2): polyurethane/polyvinylidene fluoride film preparation: mixing polyurethane and polyvinylidene fluoride, putting the mixture into a beaker containing an organic solvent N, N-dimethylacetamide for dissolution, wherein the concentration ratio of the polyurethane to the polyvinylidene fluoride is 8% -20%, stirring uniformly by a stirrer to form white sticky mixed liquid, putting the mixed liquid into a vacuum oven, vacuumizing to remove bubbles in the mixed liquid, putting the prepared solution into a casting dish for casting and film forming, putting the casting dish filled with the solution into the vacuum oven, heating in vacuum to volatilize the organic solvent N, N-dimethylacetamide in the solution, obtaining a polyurethane/polyvinylidene fluoride film, taking out the polyurethane/polyvinylidene fluoride film, carrying out uniaxial stretching on the obtained polyurethane/polyvinylidene fluoride film, putting the stretched film into the vacuum oven, annealing, taking out the polyurethane/polyvinylidene fluoride film, putting the annealed polyurethane/polyvinylidene fluoride film into the middle of the two electrode plates for compression, immersing the polyurethane/polyvinylidene fluoride film into silicone oil, connecting the high-voltage power supply to the upper surfaces of the two ends, setting voltage and polarization time, carrying out polarization, taking out the polyurethane/polyvinylidene fluoride film out the polarization, and cooling the polyurethane/polyvinylidene fluoride film in the air to room temperature after the polarization is completed;
step 3): putting the silver nanowire obtained in the step 1) into absolute ethyl alcohol, uniformly dispersing by ultrasonic, cutting the polyurethane and polyvinylidene fluoride film obtained in the step 2), sticking adhesive tapes on the periphery of the front surface of the film to form grooves, pouring the prepared silver nanowire solution into the grooves, standing in a dark place until the ethanol is completely volatilized, repeating the operation on the reverse surface of the film, finally tearing off the adhesive tapes, airing, and leading out electrodes to obtain the silver nanowire polyurethane/polyvinylidene fluoride flexible conductive film.
Preferably, the silver nanowire solution is uniformly coated on two sides of a polyurethane/polyvinylidene fluoride film, an electrode wire is pressed by a pressing roller and led out, the thickness of the silver nanowire coating is 80-120nm, the pasting width of the surrounding insulating adhesive tape is 2mm, the double-sided pasting is carried out, and the square resistance is 20.34 ohm/sqare.
Preferably, the concentration ratio of polyurethane to polyvinylidene fluoride in step 2) is 8% or 15% or 20%.
Preferably, the concentration of silver nanowires at both electrodes of the flexible thin film sensor is 1mg/ml or 2mg/ml or 3mg/ml.
The beneficial effects are that: compared with the prior art, the invention has the beneficial technical effects that: according to the invention, TPU and PVDF are mixed in a certain proportion by a simple method to form a flexible film material with a composite component, so that the flexibility and the bending property of the sensor are improved; the method is simple, the operability is strong, the stability of the obtained sensor is good, the capacitance is high, and a new thought and method are provided for the production development of the flexible sensor; the invention adopts the coating method to use AgNWs material as the electrode, replaces the traditional high-temperature sputtering method, reduces the damage of the film material and improves the sensitivity.
Drawings
Fig. 1 is an electron microscope image of a silver nanowire of the present invention.
Figure 2 is an ultraviolet spectrum of a silver nanowire of the present invention.
Fig. 3 is a schematic view of the structure of the silver nanowire material flexible thin film sensor of the present invention.
Fig. 4 is an electron micrograph of a surface of a flexible thin film sensor of silver nanowire material of the present invention.
Fig. 5 is a CV graph of a flexible thin film sensor of the invention with silver nanowires.
Fig. 6 is a graph of capacitance versus bending angle for a silver nanowire material flexible thin film sensor of the present invention.
Detailed Description
The invention adopts an AgNWs electrode coating method, and uses AgNWs as a capacitor electrode material to form a network electrode, and the square resistance is as low as 20.34 omega/sqare, so that the cost is lower, and the conduction is more sensitive. In the preparation method, polyurethane TPU components are added in the film manufacturing process to improve the defect of flexibility, and in order to solve the problem of high-temperature sputtering of the electrode, a coating method is adopted for the electrode, so that the influence of the electrode on a dielectric layer is reduced. FIG. 1 is an electron microscope image of a silver nanowire of the present invention; FIG. 2 is an ultraviolet spectrum of a silver nanowire of the present invention; FIG. 3 is a schematic diagram of a silver nanowire material flexible thin film sensor structure of the present invention; FIG. 4 is a surface electron micrograph of a flexible thin film sensor of silver nanowires of the present invention; FIG. 5 is a CV plot of a flexible thin film sensor of the silver nanowire material of the present invention; fig. 6 is a graph of capacitance versus bending angle for a silver nanowire material flexible thin film sensor of the present invention.
Fig. 1-6 show a specific embodiment of a method for preparing a flexible thin film sensor based on a silver nanowire material, which comprises the following steps:
first, silver nanowires having an aspect ratio of more than 800 are prepared by the steps of: firstly, polyvinylpyrrolidone PVP with the molecular weight of 300000 is dissolved in 100ml of glycol, and 1ml of polyvinylpyrrolidone with the concentration of 3mmol/LCuCl is added 2 And 1ml of Fe (NO) at a concentration of 2mmol/L 3 ) 3 Heating the solution to 170 ℃ and stirring for 1h, then dropwise adding 0.02g/ml silver nitrate alcohol solution, continuing to react for 2h to obtain a reaction product, washing with ethanol and centrifuging for 5 times to obtain a pure silver nanowire AgNWs solution, wherein the length of the silver nanowire ranges from 40 mu m to 60 mu m, and the diameter of the silver nanowire is 50nm;
preparation of TPU/PVDF flexible film: weighing PVDF and TPU, putting the PVDF and TPU into a beaker containing an organic solvent N, N-dimethylacetamide (DMAc), stirring for 1h by a stirrer, uniformly mixing to obtain a solution, putting the prepared solution into a vacuum oven for 30min, carrying out defoaming treatment, putting the prepared solution into a casting dish, standing the solution to be fully spread on the casting dish, putting the casting dish fully filled with the solution into a vacuum oven at 80 ℃, carrying out vacuum heating for 2h to volatilize DMAc in the solution to obtain a TPU/PVDF film, taking out and airing to room temperature, carrying out uniaxial stretching on the obtained TPU/PVDF film at 90 ℃, wherein the stretching ratio is 500%, the stretching speed is 110mm/min, putting the stretched film into a vacuum oven at 130 ℃, annealing for 2h, taking out and airing to room temperature, putting the annealed TPU/PVDF film between two electrode plates for compaction, immersing the two electrode plates into silicone oil at 80 ℃, connecting a high-voltage power supply to the upper surfaces of the two end electrode plates, setting the voltage to be 90MV/m for 30min, and after polarization, taking out the TPU/PVDF film and cooling to room temperature in air after polarization is completed;
silver nanowire polyurethane/polyvinylidene fluoride flexible conductive film: pasting the periphery of the TPU/PVDF film by using an insulating tape, coating the AgNWs solution on one side of the film, standing for 40min, and volatilizing the ethanol solution in the AgNWs solution; and the other surface is coated and dried in the same way, and the electrode is led out.
Example 1
Weighing 1.8648g of PVP, adding into 100ml of ethylene glycol, stirring and dissolving, transferring into a three-neck flask, dropwise adding 1ml of copper chloride solution with the concentration of 3mmol/L, adding ferric nitrate solution with the concentration of 1ml and 2mmol/L, adding magneton, placing into an oil bath kettle with the concentration of 170 ℃ and stirring for 1h, weighing 0.5g of silver nitrate, dissolving into 25ml of ethylene glycol, stirring and dissolving, enabling the solution to be in a dark environment during the dissolving process, dropwise adding 80ml/h of the solution into the three-neck flask, continuing to react for 2h, airing in air to room temperature after the reaction is finished, pouring the obtained grey green solution into a test tube, centrifuging for 5 times by absolute ethyl alcohol to obtain pure silver nanowires, and uniformly dispersing the silver nanowires into an ethanol solution for standby;
mixing 0.8g of TPU and 9.2g of PVDF, putting the mixture into a beaker containing 50ml of DMAc, uniformly stirring the mixture by using a magnetic stirrer to form white viscous mixed liquid, putting the mixed liquid into a vacuum oven, vacuumizing to 10MPa, carrying out normal temperature for 30min, removing bubbles in the mixed liquid, sticking adhesive tapes around a glass plate with the length of 5cm multiplied by 5cm, preparing a casting dish, pouring the mixed liquid into the casting dish, standing and the like, fully spreading the liquid, putting the casting dish fully spread with the liquid into a vacuum oven with the temperature of 80 ℃ and the pressure of 10MPa for 2h, solidifying the solution to obtain a TPU/PVDF film, taking out the TPU/PVDF film, carrying out uniaxial stretching at the temperature of 90 ℃, wherein the stretching ratio is 500%, the stretching speed is 110mm/min, putting the film into a vacuum oven with the temperature of 130 ℃, annealing for 2h, putting the annealed TPU/PVDF film into two electrode plates for middle compression, immersing the two high-pressure silicone oils in 80 ℃, connecting the power supply to the two ends, setting the voltage to be 90/m, carrying out uniaxial stretching for 30min, and cooling the PVDF film to the room temperature, and polarizing the PVDF film after the polarization in the air is taken out;
putting 200mg of silver nanowires into 10ml of absolute ethyl alcohol, uniformly dispersing by ultrasonic, cutting a TPU/PVDF film with the thickness of 3cm multiplied by 3cm, pasting a tape with the thickness of 0.5cm on the periphery of the film to form a groove, pouring the prepared AgNWs solution into the groove, standing for 30min at a dark place until the ethanol is completely volatilized, repeating the operation on the reverse side like the front side, tearing off the tape, carrying out non-metallization treatment on the edge of the film by using acetone and alcohol as corrosive agents, leading out electrodes, leading out copper sheet electrodes on the upper end and the lower end of the film coated with the electrodes, and fixing the copper sheet by using conductive silver to obtain the silver nanowire TPU/PVDF flexible conductive film.
Example 2
1.8648g of PVP is weighed and put into 100ml of ethylene glycol for stirring and dissolution, the mixture is transferred into a three-neck flask, 1ml of copper chloride solution with the concentration of 3mmol/L and 1ml of ferric nitrate solution with the concentration of 2mmol/L are added, and the mixture is placed into an oil bath pot with the temperature of 170 ℃ for stirring for 1h. 0.5g of silver nitrate is weighed and dissolved in 25ml of glycol, and the solution is in a dark environment during the dissolution process. The solution was added dropwise to a three-necked flask at 80ml/h, and the reaction was continued for 2 hours. And after the reaction is finished, airing the mixture in air to room temperature. Pouring the obtained grey green solution into a test tube, and centrifuging with absolute ethyl alcohol for 5 times to obtain the pure silver nanowires. Uniformly dispersing silver nanowires in an ethanol solution for later use;
1.5g TPU and 8.5g PVDF are mixed and placed in a beaker containing 50ml DMAc and stirred uniformly using a magnetic stirrer, forming a white viscous mixed liquid. And (3) placing the mixed liquid into a vacuum oven, vacuumizing to 10MPa, and keeping the temperature at normal temperature for 30min. Removing bubbles in the mixed liquid. Adhesive tape is stuck around a glass plate with the length of 5cm multiplied by 5cm to prepare a casting dish, and the mixed liquid is poured into the casting dish and is fully paved by standing and the like. The casting dish fully paved with liquid is placed in a vacuum oven with the temperature of 80 ℃ and the pressure of 10MPa for 2 hours. And solidifying the solution to obtain the TPU/PVDF film, taking out and airing to room temperature. The TPU/PVDF film obtained was uniaxially stretched at 90℃in a stretch ratio of 500% and at a stretch speed of 110mm/min. And (5) putting the film into a vacuum oven at 130 ℃, annealing for 2 hours, taking out, and airing to room temperature. The annealed TPU/PVDF film is placed between two electrode plates to be pressed and immersed in silicone oil at 80 ℃. The high-voltage power supply is connected to the electrode plates at the two ends, the set voltage is 90MV/m, and the polarization time is 30min. After polarization is completed, taking out the TPU/PVDF film, and placing the TPU/PVDF film in air to cool to room temperature;
putting 300mg of silver nanowires into 10ml of absolute ethyl alcohol, uniformly dispersing by ultrasonic, cutting a TPU/PVDF film with the thickness of 3cm multiplied by 3cm, sticking a tape with the thickness of 0.5cm on the periphery of the film to form a groove, pouring the prepared AgNWs solution, standing for 30min at a dark place until the ethanol is completely volatilized, and repeating the operation on the reverse side. Tearing off the adhesive tape, using acetone and alcohol as corrosive agents, carrying out non-metallization treatment on the edge of the film, leading out electrodes in the thickness direction, leading out copper sheet electrodes at the upper end and the lower end of the film coated with the electrodes, and fixing the copper sheet by using conductive silver adhesive to obtain the silver nanowire TPU/PVDF flexible conductive film.
Example 3
1.8648g of PVP is weighed and put into 100ml of ethylene glycol for stirring and dissolution, the mixture is transferred into a three-neck flask, 1ml of copper chloride solution with the concentration of 3mmol/L and 1ml of ferric nitrate solution with the concentration of 2mmol/L are added, and the mixture is placed into an oil bath pot with the temperature of 170 ℃ for stirring for 1h. 0.5g of silver nitrate is weighed and dissolved in 25ml of glycol, and the solution is in a dark environment during the dissolution process. The solution was added dropwise to a three-necked flask at 80ml/h, and the reaction was continued for 2 hours. And after the reaction is finished, airing the mixture in air to room temperature. Pouring the obtained grey green solution into a test tube, and centrifuging with absolute ethyl alcohol for 5 times to obtain the pure silver nanowires. Uniformly dispersing silver nanowires in an ethanol solution for later use;
2g TPU and 8g PVDF are mixed and placed in a beaker containing 50ml DMAc and stirred uniformly by means of a magnetic stirrer, so that a white viscous mixed liquid is formed. And (3) placing the mixed liquid into a vacuum oven, vacuumizing to 10MPa, and keeping the temperature at normal temperature for 30min. Removing bubbles in the mixed liquid. Adhesive tape is stuck around a glass plate with the length of 5cm multiplied by 5cm to prepare a casting dish, and the mixed liquid is poured into the casting dish and is fully paved by standing and the like. And (3) placing the casting dish fully paved with the liquid into a vacuum oven with the temperature of 80 ℃ and the pressure of 10MPa for 2 hours, solidifying the solution to obtain the TPU/PVDF film, taking out and airing to the room temperature. Uniaxially stretching the TPU/PVDF film at 90 ℃ at a stretching ratio of 500% and a stretching speed of 110mm/min, putting the film into a vacuum oven at 130 ℃, annealing for 2 hours, and taking out and airing to room temperature. Pressing the annealed TPU/PVDF film between two electrode plates, immersing the TPU/PVDF film in silicone oil at 80 ℃, connecting a high-voltage power supply to the electrode plates at the two ends, setting the voltage to be 90MV/m, polarizing for 30min, taking out the TPU/PVDF film after polarizing, and cooling the TPU/PVDF film to room temperature;
taking 400mg of silver nanowires, putting the silver nanowires into 10ml of absolute ethyl alcohol, and uniformly dispersing the silver nanowires by ultrasonic waves. Cutting a TPU/PVDF film with the thickness of 3cm multiplied by 3cm, sticking a tape with the thickness of 0.5cm on the periphery of the film to form a groove, pouring the prepared AgNWs solution, and standing in a dark place for 30min until the ethanol is completely volatilized. The reverse side is operated repeatedly. Tearing off the adhesive tape, using acetone and alcohol as corrosive agents, carrying out non-metallization treatment on the edge of the film, and avoiding short circuit of the treated film in the thickness direction. And leading out electrodes, namely leading out copper sheet electrodes at the upper end and the lower end of the film coated with the electrodes, and fixing the copper sheets by using conductive silver glue to obtain the silver nanowire TPU/PVDF flexible conductive film.
Comparative example 1: in comparison with example 1, the AgNWs alcoholic solution was formulated at a concentration of 2mg/ml, the other steps being unchanged.
Comparative example 2: in comparison with example 1, the AgNWs alcoholic solution was formulated at a concentration of 3mg/ml, the other steps being unchanged.
Comparative example 3: in comparison with example 2, the AgNWs alcohol solution was prepared at a concentration of 1mg/ml, with the other steps unchanged.
Comparative example 4: in comparison with example 2, the AgNWs alcohol solution was prepared at a concentration of 3mg/ml, with the other steps unchanged.
Comparative example 5: in comparison with example 3, the AgNWs alcoholic solution was formulated at a concentration of 1mg/ml, with the other steps unchanged.
Comparative example 6: in comparison with example 3, the AgNWs alcoholic solution was formulated at a concentration of 2mg/ml, the other steps being unchanged.
Table 1:
as can be seen from table 1, as the AgNWs concentration increases, the AgNWs attached to the film surface increases, the sheet resistance decreases, and the conductivity increases.
As can be seen from table 1, the capacitance was maximum at 375 μf/g when TPU: pvdf=1:20, and the capacitance of the TPU/PVDF sensor increased with increasing TPU/PVDF mass ratio.
As can be seen from table 1, the elongation at break of the flexible film sensor increases significantly with increasing TPU/PVDF mass ratio. Increasing from 44.3% to 91.2%.
The invention adopts silver nanowire material as capacitance electrode material, and polyurethane/polyvinylidene fluoride (TPU/PVDF) polarized flexible film as capacitance dielectric layer, and the combined flexible capacitance sensor has the characteristics of high sensitivity and high response speed. The sensor bending angle and the capacitance output show linear positive correlation trend, and the analysis software is utilized to perform linear fitting on the data to obtain a capacitance value
Correlation coefficient R 2 =0.996; good linearity, the slope of the linear output is 9.11×10 -4 ±3.32×10 -5 The slope is obviously different from zero, and the silver nanowire material with high length-diameter ratio (with the length-diameter ratio of more than 800) is used as the electrode material of the sensor capacitor, so that the conductivity of the electrode is effectively increased, and the problem of insufficient flexibility of the traditional sensor is solved by adding the TPU material. The preparation method is simple, has low requirements on equipment and low cost, and provides a new method approach for perfecting the flexible film sensor.
Finally, it should be noted that the invention is not limited to the above embodiments, but that many variants are possible. All modifications directly derived or suggested to one skilled in the art from the present disclosure should be considered as being within the scope of the present invention.
Claims (3)
1. The preparation method of the flexible film sensor based on the silver nanowire material is characterized by comprising the following steps:
step 1): preparing silver nanowires with an aspect ratio of more than 800: dissolving polyvinylpyrrolidone with a molecular weight of 300000 in 100ml of ethylene glycol, adding copper chloride with a concentration of 3mmol/L and ferric nitrate with a concentration of 2mmol/L, heating to 170 ℃ and stirring for 1h, then dropwise adding silver nitrate alcohol solution with a concentration of 0.02g/ml, continuing to react for 2h, airing to room temperature in air after the reaction is finished, pouring the obtained grey green solution into a test tube, washing with absolute ethyl alcohol and centrifuging for 5 times to obtain pure silver nanowires, and uniformly dispersing the silver nanowires in the ethanol solution for later use;
step 2): polyurethane/polyvinylidene fluoride film preparation: mixing polyurethane and polyvinylidene fluoride, putting the mixture into a beaker containing an organic solvent N, N-dimethylacetamide for dissolution, wherein the concentration ratio of the polyurethane to the polyvinylidene fluoride is 8% -20%, stirring uniformly by a stirrer to form white sticky mixed liquid, putting the mixed liquid into a vacuum oven, vacuumizing to remove bubbles in the mixed liquid, putting the prepared solution into a casting dish for casting and film forming, putting the casting dish filled with the solution into the vacuum oven, heating in vacuum to volatilize the organic solvent N, N-dimethylacetamide in the solution, obtaining a polyurethane/polyvinylidene fluoride film, taking out the polyurethane/polyvinylidene fluoride film, carrying out uniaxial stretching on the obtained polyurethane/polyvinylidene fluoride film, putting the stretched film into the vacuum oven, annealing, taking out the polyurethane/polyvinylidene fluoride film, putting the annealed polyurethane/polyvinylidene fluoride film between the two electrode plates for compression, immersing the polyurethane/polyvinylidene fluoride film into silicone oil, connecting a high-voltage power supply to the upper surfaces of the two ends, setting voltage and time, carrying out polarization, taking out the polyurethane/polyvinylidene fluoride film out the polarization, and cooling the polyurethane/polyvinylidene fluoride film in the air to room temperature after the polarization is completed;
step 3): putting the silver nanowire obtained in the step 1) into absolute ethyl alcohol, uniformly dispersing by ultrasonic, cutting the polyurethane and polyvinylidene fluoride film obtained in the step 2), sticking adhesive tapes on the periphery of the front surface of the film to form grooves, pouring the prepared silver nanowire solution into the grooves, standing in a dark place until the ethanol is completely volatilized, repeating the operation on the reverse surface of the film, finally tearing off the adhesive tapes, airing, and leading out electrodes to obtain the silver nanowire polyurethane/polyvinylidene fluoride flexible conductive film;
uniformly coating silver nanowire solution on two sides of a polyurethane/polyvinylidene fluoride film, compacting by a compression roller, leading out electrode wires, wherein the thickness of the silver nanowire coating is 80-120nm, the pasting width of a surrounding insulating tape is 2mm, the double-sided pasting is carried out, and the square resistance is 20.34 ohm/sqare.
2. The method for preparing the flexible thin film sensor based on the silver nanowire material, as claimed in claim 1, is characterized in that: the concentration ratio of polyurethane to polyvinylidene fluoride in the step 2) is 8% or 15% or 20%.
3. The flexible thin film sensor based on silver nanowire materials and the preparation method thereof as claimed in claim 1, wherein the flexible thin film sensor is characterized in that: the concentration of silver nanowires at the two electrodes of the flexible film sensor is 1mg/ml or 2mg/ml or 3mg/ml.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110333939.XA CN112985470B (en) | 2021-03-29 | 2021-03-29 | Flexible capacitance sensor based on silver nanowire material and preparation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110333939.XA CN112985470B (en) | 2021-03-29 | 2021-03-29 | Flexible capacitance sensor based on silver nanowire material and preparation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112985470A CN112985470A (en) | 2021-06-18 |
| CN112985470B true CN112985470B (en) | 2023-04-28 |
Family
ID=76338853
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110333939.XA Active CN112985470B (en) | 2021-03-29 | 2021-03-29 | Flexible capacitance sensor based on silver nanowire material and preparation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112985470B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114199426A (en) * | 2021-12-03 | 2022-03-18 | 宁波诺丁汉新材料研究院有限公司 | Flexible sensing layer, preparation method of flexible sensor and flexible sensor |
| CN114327130A (en) * | 2021-12-15 | 2022-04-12 | 北京工业大学 | Flexible high-light-transmission electronic skin simulating artificial tactile feedback and application |
| CN114526849A (en) * | 2022-02-23 | 2022-05-24 | 重庆文理学院 | Preparation method of non-woven fabric-based flexible pressure sensor |
| CN114705739B (en) * | 2022-03-07 | 2024-04-12 | 浙江理工大学 | Capacitive immunosensor for detecting silk fibroin based on RGO-Ag-ZnO-PPy |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101691202A (en) * | 2009-08-11 | 2010-04-07 | 西安交通大学 | Method for preparing polyvinylidene fluoride piezo film with microstructure |
| CN104157784A (en) * | 2014-07-31 | 2014-11-19 | 北京科技大学 | Preparation method of composite nanometer piezoelectric generator |
| CN107036657A (en) * | 2017-05-19 | 2017-08-11 | 重庆大学 | A kind of magnetic, power cilium biomimetic sensor and preparation method thereof |
| CN110260893A (en) * | 2019-06-18 | 2019-09-20 | 广东工业大学 | A kind of preparation method of condenser type flexible sensor |
| CN110656326A (en) * | 2019-09-19 | 2020-01-07 | 山东非金属材料研究所 | Preparation method of polyvinylidene fluoride piezoelectric film surface electrode |
| CN111664970A (en) * | 2020-05-28 | 2020-09-15 | 浙江大学 | Self-powered flexible pressure sensing device and preparation method thereof |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107478360B (en) * | 2017-08-18 | 2020-05-19 | 北京纳米能源与系统研究所 | Capacitive flexible pressure sensor and preparation method thereof |
| CN108072389B (en) * | 2017-11-30 | 2019-09-03 | 西安交通大学 | A kind of wearable health monitoring sensor manufacturing process of bionical attaching type |
| CN109901738A (en) * | 2017-12-11 | 2019-06-18 | 宸鸿科技(厦门)有限公司 | Touch sensing, touch panel and preparation method thereof |
| CN108543113A (en) * | 2018-03-21 | 2018-09-18 | 浙江理工大学 | A kind of preparation method of transparent photosensitive artificial skin sensor |
| CN108560250B (en) * | 2018-04-24 | 2020-08-18 | 中国人民解放军总医院 | Preparation method and application of flexible strain sensor based on conductive fibers |
| CN109338714B (en) * | 2018-09-04 | 2021-07-30 | 浙江理工大学 | Preparation method of nano silver wire composite polyester conductive fabric |
| CN109387307B (en) * | 2018-12-12 | 2020-08-11 | 深圳大学 | Flexible stress sensor and preparation method thereof |
-
2021
- 2021-03-29 CN CN202110333939.XA patent/CN112985470B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101691202A (en) * | 2009-08-11 | 2010-04-07 | 西安交通大学 | Method for preparing polyvinylidene fluoride piezo film with microstructure |
| CN104157784A (en) * | 2014-07-31 | 2014-11-19 | 北京科技大学 | Preparation method of composite nanometer piezoelectric generator |
| CN107036657A (en) * | 2017-05-19 | 2017-08-11 | 重庆大学 | A kind of magnetic, power cilium biomimetic sensor and preparation method thereof |
| CN110260893A (en) * | 2019-06-18 | 2019-09-20 | 广东工业大学 | A kind of preparation method of condenser type flexible sensor |
| CN110656326A (en) * | 2019-09-19 | 2020-01-07 | 山东非金属材料研究所 | Preparation method of polyvinylidene fluoride piezoelectric film surface electrode |
| CN111664970A (en) * | 2020-05-28 | 2020-09-15 | 浙江大学 | Self-powered flexible pressure sensing device and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112985470A (en) | 2021-06-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112985470B (en) | Flexible capacitance sensor based on silver nanowire material and preparation method | |
| CN108168420B (en) | Flexible strain sensor based on MXene material | |
| Hong et al. | UV curable conductive ink for the fabrication of textile-based conductive circuits and wearable UHF RFID tags | |
| CN109095782B (en) | Preparation method of silver nanowire transparent conductive film based on three-dimensional microstructure | |
| CN109631957A (en) | A kind of stretchable hypersensitive electronic skin and its preparation method and application | |
| CN109781312B (en) | Capacitive pressure sensor and preparation method thereof | |
| CN111504527B (en) | Sea urchin-shaped oxide-based composite membrane bionic pressure sensor and preparation method thereof | |
| CN101078704A (en) | Polyelectrolyte / intrinsic conducting polymer composite humidity sensor and its production method | |
| CN113959603A (en) | Flexible capacitive pressure sensor and manufacturing method thereof | |
| CN110085445A (en) | A kind of flexible super capacitor and preparation method thereof | |
| CN112759700B (en) | All-solid-state ion-conductive elastomer and preparation and application thereof | |
| CN109085204A (en) | A kind of transparent flexible humidity sensor and preparation method thereof | |
| CN105185898A (en) | Flexible transparent functional device and preparation method thereof | |
| Feng et al. | Stretchable multifunctional dielectric nanocomposites based on polydimethylsiloxane mixed with metal nanoparticles | |
| CN112505106A (en) | Paper-based ethanol gas sensor | |
| Chen et al. | Silver nanowire/polymer composite soft conductive film fabricated by large-area compatible coating for flexible pressure sensor array | |
| CN107898463B (en) | Flexible electronic pressure sensor and preparation method thereof | |
| CN113166603B (en) | Pressure-sensitive adhesive sheet | |
| CN105910737B (en) | A kind of stress alignment sensor and preparation method thereof, stress localization method | |
| CN108955960A (en) | A kind of flexible touch sensation sensor of oxide thin film transistor formula | |
| CN108962433A (en) | A kind of preparation method of the flexible transparent conductive film of metal ordered grid | |
| KR20190101208A (en) | Manufacturing Method of Conductive polymer coated Graphene-AgNWs nano-composites electrode | |
| CN110514230A (en) | Stretch bending flexible sensor and preparation method thereof | |
| CN110579295A (en) | Pressure sensor and method for manufacturing the same | |
| CN114927285A (en) | Flexible transparent film electrode and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |