WO2022252021A1

WO2022252021A1 - Flexible temperature sensor array and preparation method therefor

Info

Publication number: WO2022252021A1
Application number: PCT/CN2021/097294
Authority: WO
Inventors: 李晖; 苏毅; 朱正芳; 王磊
Original assignee: 中国科学院深圳先进技术研究院
Priority date: 2021-05-31
Filing date: 2021-05-31
Publication date: 2022-12-08

Abstract

A flexible temperature sensor array, comprising a thermosensitive layer, a flexible substrate (4), and a wire (3). The thermosensitive layer is provided on the flexible substrate (4); the thermosensitive layer is formed by arranging a plurality of temperature sensing units (1) at fixed intervals; the wire (3) is adhered to the flexible substrate (4) according to a set line and is connected to the temperature sensing units (1); each temperature sensing unit (1) is prepared from (poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate))/carbon nanotube/reduced graphene oxide composite film. The preparation process of the method is simple and environment-friendly; the sensitivity, the degree of linearity, the precision, and the response time of the sensor array are improved; converting a temperature-resistance value into a visual image can be achieved; and the present invention further has the characteristics of strong in durability and stability and low in power consumption.

Description

A flexible temperature sensor array and its preparation method

technical field

The invention belongs to the field of sensor materials, in particular to a flexible temperature sensor array and a preparation method thereof.

Background technique

In recent years, there has been an increasing demand for flexible sensors or flexible sensing arrays used in the process of human-computer interaction. In terms of human-computer interaction, a wearable device is a wearable portable computing device embedded with a variety of high-precision sensors as input terminals. At present, the relatively new human-computer interaction technology in the wearable device industry will have a profound impact on the information exchange and communication methods between humans and machines. The sense of touch is one of the important channels for human beings to communicate with and experience the outside world. Information such as softness, hardness, temperature, size, and shape of an object can be perceived through touch. Tactile interaction research how to use tactile information to enhance communication between humans and computers and robots, thanks to technological advances in sensors, algorithms, and chips, the application potential of human-computer interaction technology has begun to show, including surgical simulation training, entertainment, and robot remote control , telemedicine, robot skin and other fields. The infinite potential of wearable devices also makes them the direction of scientific research, and will also be a key interactive technology for humans to "real" perceive the outside world in virtual reality in the future. The application and development of hotspot technologies are both opportunities and challenges. Among them, the sensing array based on temperature sensors has low recognition rate and poor real-time performance. It is necessary to perform performance optimization, data processing, algorithm optimization and other methods for flexible sensors to improve the sensing effect. In addition, a more reasonable arrayed temperature sensor has far-reaching practical significance for robots to recognize objects and realize the role of robots in autonomously sensing the outside world and realizing functions similar to human skin.

At present, there are mainly the following methods for the preparation of flexible temperature sensing arrays:

1. Use 0.5 mL of dimethyl sulfoxide as a conductivity enhancer, and then add it to 10 mL of PEDOT:PSS aqueous solution. Graphene nanosheets were added to the above mixed solution. The mixed solution was dispersed with magnetic stirring at room temperature for 3 h, and then placed in a 50 W ultrasonic bath for 15 min. The dispersed solution was drop-cast onto a polyimide substrate soaked in 10% HCl (hydrochloric acid) solution for 1 hour. Place on a heating plate and anneal at 150° C. for 1 hour to obtain a non-transparent graphene/PEDOT:PSS film with a thickness of 3-4 microns. Next, an aqueous PVA (polyvinyl alcohol) solution was drop-cast onto the dry PEDOT:PSS/graphene composite surface. The composite was dried at ambient conditions for more than 48 hours. Finally, the PEDOT:PSS/graphene/PVA composite was exfoliated from the polyimide substrate. Printing electrodes through a mask can form flexible, translucent sensor arrays. The flexible temperature sensor prepared by this method has strong transparency and pyroelectric performance.

2. GPANI (polyaniline/graphene), PVB (polyvinyl butyral), and absolute ethanol were mixed and stirred at a mass ratio of 0.1:5:100 for 4 hours, and then ultrasonically treated for 30 minutes. The flexible substrate is made of 10 strip-shaped ITO electrodes with a width of 4 mm arranged in parallel on a PET film at an interval of 1 mm. Then the treated mixture was evenly coated on the ITO-PET substrate with a Meller rod coater, followed by annealing at 80 °C for 15 minutes to eliminate alcohol and form a dry film. In the absence of any gap, the same ITO-PET substrate was attached to the film, and the electrodes on the upper and lower ITO-PET substrates were vertically divided into steps. The top and bottom substrates were fixed with ultraviolet epoxy tape around the PET to complete the preparation of the GPANI-PVB composite film temperature sensor. The flexible sensor has the advantages of high transparency and simple array preparation.

3. Mix sulfuric acid (360ml)/phosphoric acid (40ml) with 3g graphite. Then 18 g of potassium permanganate was added dropwise into the above mixture while continuously stirring at a constant temperature of 45° C. for 16 h. The mixture was then cooled to room temperature, and the dispersion was quenched by pouring the dispersion onto 400 g of ice. Hydrogen peroxide was slowly added dropwise to the cooled solution until the dispersion turned whitish yellow. The slurry was separated from the acid by centrifugation and then resuspended in deionized water. The resulting GO (graphene oxide) was washed twice with hydrochloric acid and then washed three times with ethanol. The above slurry was centrifuged at 20,000 rpm for 10 minutes, and then the solution was replaced with acetic acid twice. The GO slurry was transferred to acetic acid to form a concentration of 1 mg mL. ^-1 solution. The mixture was boiled, and about 0.04 g of PHB (polyhydroxybutyric acid) granules were added as a stabilizer; heated with vigorous stirring at 118 ° C for 2 h, and ascorbic acid was added to the suspension (ascorbic acid: GO weight ratio was 2: 1 ). The rGO (reduced graphene oxide)/PHB composite solution was formed by stirring at 118 °C. In order to make a temperature sensor, shake the composite solution well, then drop a drop onto the printed silver electrode on the flexible PET substrate on a hot plate at 140°C, and continue to heat the substrate for about 1min until all the solvent evaporates to achieve temperature sensitivity. array. The sensing array has the capability to map the temperature profile of the object.

4. 0.5 g of primary particle state NiO (nickel oxide) powder with a diameter of 50 nm was mixed with 1 g of ethylene glycol and 9 g of deionized water to form an aqueous mixture. The NiO mixture was then sonicated with a homogenizer for 10 min. Silver nanoparticles were synthesized by reduction of AgNO3 with diethanolamine. The synthesized silver nanoparticles were centrifuged, washed and resuspended in 30 vol% aqueous ethylene glycol to form a 10 wt% silver ink. The silver and NiO mixed ink was centrifuged again at 3000 rpm for 10 min. A piezoelectric printer was used to print patterns on glass plates or polyimide films, in which the mixed ink of silver and NiO was jetted into droplets with a diameter of 55 μm under the condition of jetting speed of 2.5 m/s. Print patterns at a printing speed of 25mm/s with a dot pitch of 50μm to form straight or square films. The silver wire deposited with the NiO thin film was heated in a furnace at a temperature of 200° C. for 1 hour.

Although the above sensing array can basically sense the temperature of the object, there are still some deficiencies.

1. The flexible temperature sensing array based on PEDOT:PSS/graphene has large measurement fluctuations and small application range.

2. The flexible temperature sensing array based on GPANI/PVB has a small sensing range and a large volume.

3. The flexible temperature sensing array based on PHB/rGO has a complicated preparation process and low sensitivity.

4. The flexible temperature sensing array based on NiO/Ni ink has a short lifespan and requires high equipment requirements.

Contents of the invention

The invention mainly aims at the technical problems that the current flexible temperature sensing array is not high in sensitivity, low in precision, complex in preparation process and long in response time, and is not suitable for rehabilitation robots, and invented a composite material based on PEDOT:PSS/CNTs/rGO The flexible temperature sensing array not only greatly improves the sensing accuracy and sensing range, but also reduces the response time of the sensor. Specifically, it is realized through the following technical solutions:

The invention provides a flexible temperature sensor array, which includes a thermosensitive layer, a flexible substrate and wires, and the thermosensitive layer is arranged on the flexible substrate;

The thermosensitive layer is formed by a number of temperature sensing units arranged at fixed intervals;

The wire is adhered to the flexible substrate according to the set route and connected with the temperature sensing unit;

The temperature sensing unit is prepared from (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid))/carbon nanotube/reduced graphene oxide composite film.

Further, the several temperature sensing units are connected by multiplexing lines.

Further, the plurality of temperature sensing units are arranged in a square array, a rhombus array, a sector array, a circular array or a ring array.

The present invention also provides a method for preparing the above-mentioned flexible temperature sensor array, comprising the following steps:

Add the modified single-walled carbon nanotubes and reduced graphene oxide into (poly(3,4-ethylenedioxythiophene): poly(styrenesulfonic acid)) aqueous solution, and after dispersing evenly, vacuum filter and dry , to obtain the (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid))/carbon nanotube/reduced graphene oxide composite film;

Cut the (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid))/carbon nanotube/reduced graphene oxide composite film according to the set pattern structure to obtain several temperature sensing units ;

adhering the plurality of temperature sensing units on the flexible substrate at a fixed distance;

The wire is adhered to the flexible substrate according to the set route and connected with the temperature sensing unit through the silver paste to form a multiplexing circuit;

After the silver paste is solidified, it is packaged and dried to obtain the flexible temperature sensor array.

Further, it specifically includes the following steps:

S1. Pickling carbon nanotubes: Take carbon nanotube powder and add it to H ₂ SO ₄ /H ₂ O ₂ mixed solution, heat and condense to reflux, after cooling to room temperature, wash with deionized water until the solution becomes neutral, The solution is vacuum filtered and then dried to obtain acid-washed carbon nanotubes;

S2. Preparation of reduced graphene oxide: add graphene oxide powder into water to obtain a dispersed graphene oxide solution, drop a reducing agent into the graphene oxide solution, and obtain a reduced graphene oxide solution through reaction; then the The reduced graphene oxide solution is washed to neutrality, suction filtered and dried to obtain reduced graphene oxide powder;

S3. Prepare a composite solution: add dimethyl sulfoxide solution to the PEDOT:PSS aqueous solution, then add the acid-washed carbon nanotubes described in S1, the reduced graphene oxide powder and dodecylbenzenesulfonate described in S2 sodium bicarbonate powder, stirred and dispersed to obtain a composite solution;

S4. Preparation of composite film: centrifuge the composite solution described in S3, then suction filter, then heat and dry to obtain (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid))/carbon nanotube/ Reduced graphene oxide composite film;

S5. Cutting and forming: cutting the (poly(3,4-ethylenedioxythiophene): poly(styrenesulfonic acid))/carbon nanotube/reduced graphene oxide composite film according to the set graphic structure to obtain A number of temperature sensing units;

S6. Assembling the flexible temperature sensor array: transfer the temperature sensing units cut and formed in S5 to the flexible substrate coated with an adhesive layer, and arrange them at fixed intervals; adhere the wires to the flexible substrate according to the set route on the substrate and connected with the heat-sensitive layer through silver paste to form a multiplexing circuit; after the silver paste is cured, it is packaged and dried to obtain the flexible temperature sensor array.

Further, in the step S1, the ratio of the carbon nanotubes to the H ₂ SO ₄ /H ₂ O ₂ mixed solution is (0.01-0.03) g: (10-30) mL, and the H ₂ SO 4 _{The 4} /H ₂ O ₂ mixed solution is a mixed solution of 100mL 2mol/L sulfuric acid aqueous solution and 30% hydrogen peroxide aqueous solution with a volume ratio of (4-5):1.

Further, in the step S3, an aqueous solution of (poly(3,4-ethylenedioxythiophene): poly(styrenesulfonic acid)) with a mass fraction of 1.3 wt%, poly(3,4-ethylenedioxythiophene) ) to poly(styrene sulfonic acid) mass ratio is 5:8.

Further, in the step S3, the mass ratio of the acid-washed carbon nanotubes added in S1 to the reduced graphene oxide powder in S2 is 1:1.

Further, in the step S3, the amount of sodium dodecylbenzenesulfonate powder added is 10 times that of the acid-washed carbon nanotubes added in S1 and the reduced graphene oxide powder added in S2.

Further, in the step S5, the mass ratio of the polydimethylsiloxane prepolymer to the curing agent is (9-12):1, and the spin-coating speed is 1000-2000rpm, and the spin-coating time is 5-15s .

The present invention also provides the application of the above-mentioned flexible temperature sensor array in a wearable device as tactile interactive sensing.

Compared with the existing methods for preparing flexible temperature sensing arrays, the unique PEDOT:PSS/CNTs/rGO composite film and acquisition circuit design of the present invention not only makes the preparation process of the sensing array simpler and more environmentally friendly, but also improves the sensing performance. Sensitivity, linearity, precision and response time of the array, the minimum temperature that can be sensed is 0.1°C, and the temperature-resistance value can be converted into a visual image. In addition, the present invention also has strong durability and stability. Due to the biocompatibility, low cost, and non-toxic properties of PDMS itself, with the simple structure and external circuit, the processing difficulty and preparation cost of the sensor are greatly reduced. At the same time, the sensor of the invention also has the characteristics of low power consumption.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

Fig. 1 is a kind of flexible temperature sensor array acquisition circuit diagram provided by the embodiment of the present invention;

Fig. 2 is a top view of a flexible temperature sensor array provided by an embodiment of the present invention;

Fig. 3 is a side view of a flexible temperature sensor array provided by an embodiment of the present invention;

Fig. 4 is a temperature-resistance test data diagram of a single flexible temperature sensor in a flexible temperature sensor array provided by an embodiment of the present invention;

Fig. 5 is a physical test diagram of a flexible temperature sensor array provided by an embodiment of the present invention;

FIG. 6 is a flowchart of a method for fabricating a flexible temperature sensor array provided by an embodiment of the present invention.

Reference signs:

1-temperature sensing unit; 2-conductive silver paste; 3-copper wire; 4-PDMS flexible substrate.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Facing the application and development of future human-computer interaction scenarios, research on the multiple cooperation of flexible temperature sensing arrays in monitoring limb rehabilitation, temperature analysis of equipment and skin contact parts, and accurate real-time acquisition of signals will help improve the human-computer interaction process. The signal processing efficiency and precise control during operation, as well as the timely adjustment of the working state of the robot according to the human body, have great clinical significance, and are also major scientific and industrial problems that need to be solved urgently in the field of basic technology. The human body can show different degrees of avoidance behavior to abnormal heat sources, not only because the skin can distinguish abnormal temperatures, but also because the skin can distinguish the heat range of abnormal heat sources. For the robotic skin, carbon nanotubes (CNTs), reduced graphene oxide (rGO) and (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid)) (PEDOT:PSS) composites The prepared flexible thermosensitive film is used as a sensing unit, and multiple independent sensors are regularly integrated on the same substrate. The sensing array system directly addresses each sensing unit in the array, and measures the temperature in the array in real time. The resistance value of each device can realize the pixelization of temperature performance in the sensing process. Through the acquisition and processing of data by the host computer, the temperature can be visualized and displayed, and the function of identifying the shape of the object with temperature can be recognized.

A flexible temperature sensor array proposed by the present invention, the flexible temperature sensor array uses soft PDMS as the base material, prepares PEDOT:PSS/CNTs/rGO composite film, and cuts it into a certain size and quantity according to the requirements, and then presses the fixed spacing Bonded on the base material to form a heat-sensitive layer, connect wires, form multiplexing lines to realize array collection. When the sensing unit on the array is working, due to the external temperature change, the composite material is stimulated by temperature, and the carrier concentration inside the material changes, resulting in a change in resistance value, realizing the function of sensing pressure. When multiple sensing units feel a warm object at the same time, each sensing unit can sense the temperature independently because the designed circuit has the function of independent acquisition, realizing the result of visualizing the temperature.

Example

The first step, pickling carbon nanotube: get 0.02g carbon nanotube powder and join in the round bottom flask that magneton is housed, slowly add the mixed solution of 20ml (concentration 2mol/L sulfuric acid and the mixing of 30% hydrogen peroxide solution, mixed in a volume ratio of 3:1). Heat and stir in a silicone oil bath at 100°C, condense and reflux for 12 hours, then cool the solution to room temperature. Then carry out impurity removal and neutralization treatment, wash the solution with deionized water until the solution becomes neutral after comparing the pH with pH test paper. Next, the neutral mixed solution containing carbon nanotubes is vacuum filtered until only solid carbon nanotube powder remains on the filter paper, and then put into a vacuum freeze-drying oven to dry overnight to obtain acid-washed carbon nanotubes.

The volume ratio of sulfuric acid and hydrogen peroxide can be adjusted within the range of (4-5): 1. SWCNTs are prone to agglomeration in the solution. Using a mixed solution of sulfuric acid/hydrogen peroxide in this volume ratio range can effectively reduce the agglomeration of SWCNTs To avoid the adverse effect of SWCNT agglomeration on the conductivity of the material.

The second step, preparation of reduced graphene oxide: put 0.5g GO (graphene oxide) powder into a beaker, add 250ml deionized water, and carry out an ultrasonic dispersion process set to 200W in an ultrasonic disperser for 2 hours to obtain GO solution after ultrasonic dispersion, magnetically stir the GO solution, add 100ml 10% concentration of L-antibacterial acid solution dropwise evenly and slowly, and continue stirring for 30 minutes to obtain rGO (reduced graphene oxide ) solution. Washing is then carried out until the solution is a neutral solution. The rGO powder was obtained by vacuum filtration, and the powder was dried in a freeze drying oven for 6 hours to obtain the rGO powder used in the experiment.

Ascorbic acid solution acts as a reducing agent. The ratio of graphene oxide powder to ascorbic acid can be adjusted in the range of (0.4-0.6) g: (90-110) mL. Non-essential functional groups further enhance the conductivity of the material.

The third step, prepare composite solution: in 20mL ultrapure water, use 0.3mL dimethyl sulfoxide as conductivity enhancer, then add it into 6mL PEDOT:PSS aqueous solution (1.3wt%, the ratio of PEDOT and PSS is 5:8). According to the required content, add acid-washed carbon nanotubes and experimentally prepared redox graphene (according to the ratio of 1:1). Finally, add SDBS (sodium dodecylbenzenesulfonate) powder 10 times the weight of the carbon material mixture. The mixed solution was fully stirred and mixed in a mixer, and then ultrasonic (ice-water bath) treatment was performed for 45 minutes in an ultrasonic disperser. Obtain the PEDOT:PSS/CNTs/rGO composite composite solution.

The mass ratio of single-walled carbon nanotubes, reduced graphene oxide and (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid)) is preferably in the range of 1:1:(3-39), three The mass ratio of the former will affect the sensitivity, response speed and other properties of the entire flexible sensor. Sodium dodecylbenzenesulfonate is used as a surfactant, and its dosage is adjusted according to the actual added carbon material, which is 10 times the mass of the added carbon material, which can effectively disperse the carbon material and enhance the conductivity of the material.

The fourth step, preparing the substrate: the mixed solution of PDMS and curing agent (mass ratio is 10:1), stirred at 2000rpm for 30 seconds, and then spun on a clean silicon substrate washed with acetone, absolute ethanol and ultrapure water. coated to obtain a flexible PDMS substrate. Before spin coating, evenly spray a layer of release agent on the silicon wafer to facilitate subsequent smooth release molding.

The fifth step, spin-coating base and adhesive layer: the PDMS base layer spin-coating process adopts a rotating speed of 1500rpm, and spins for 10 seconds. After the spin-coating of PDMS is completed, the silicon wafer with PDMS is placed in a blast drying oven at 70 ℃ temperature curing for 30 minutes. After the PDMS is cured, the EcoFlex adhesive film layer can be prepared. EcoFlex solution A: B solution is mixed at a mass ratio of 1:1, and then spin-coated on the silicon wafer with the flexible substrate PDMS at a speed of 1300rpm for 10 seconds, spin coating After the process is completed, let it stand at room temperature for 7 minutes to make it semi-cured.

Spin-coating speed can be adjusted in the range of 1000-2000rpm, spin-coating time can be adjusted in the range of 5-15s, the mass ratio of PDMS and curing agent can be adjusted in the range of (9-12): 1, spin-coating speed, duration and The mass ratio of PDMS to curing agent will affect the thickness of the PDMS substrate, thereby affecting the sensitivity of the flexible temperature sensor.

The sixth step, vacuum filtration to prepare the heat-sensitive layer: use 0.22 micron pore size PVDF filter membrane to realize solution suction filtration, and perform suction filtration on the ultrasonically treated PEDOT:PSS-CNTs-rGO dispersion (in a centrifuge before vacuum filtration) Carry out centrifugation treatment at 5000 rpm for 2 hours, and take the sediment solution) for treatment. After the vacuum filtration is completed, place on a heating plate and heat at 50° C. for 2 hours. In order to enhance its electrical properties, the formed membrane structure can be immersed in DMSO solution for 12 hours, followed by drying at 60 °C for 2 hours. Obtain PEDOT:PSS/CNTs/rGO composite thin film.

The seventh step, cutting and forming: fix the heat-sensitive layer on the plane, use the AUTOCAD software to design the required graphic structure and import it into the laser printer software, and form a 1cm ² square film after cutting by the laser cutting machine.

The eighth step, bonding the substrate: transfer the composite heat-sensitive film cut and formed in the previous step to the adhesive substrate at a fixed interval according to the arrangement shown in Figure 1, and ensure that the bonding part is flat and free of cracks, bubbles, wrinkles, etc. Bad contact occurs.

The ninth step, connecting the wires: the copper wires are adhered to the flexible substrate according to the circuit form (Figure 1) and connected with the composite film through the quick-drying conductive silver paste.

Step 10, Encapsulation: Put the conductive silver paste into the blower dryer at 60°C for 2 hours, take it out and spin-coat the PDMS encapsulation layer on the sensor array. Seconds, after spin-coating the PDMS encapsulation layer, curing in a blast dryer at 70°C for 30 minutes can complete the fabrication of the flexible temperature sensing array.

The temperature test is carried out on a single flexible temperature sensing unit (sensor) in the array, and the resistance change rate and temperature change curve are obtained (Figure 4). The sensitivity is 0.9125% ℃ ^-1 and the linearity is 99.86%. It can be seen that the sensor has excellent sensitivity and linearity. The reason is that as the temperature rises, the sensitivity also changes. The reason is that as the temperature rises, the carrier concentration in the compound increases, and as the carbon nanotubes form a conductive path in the compound, the electrons move directional after being heated. Speed up and the resistance decreases.

Connect the temperature sensing array with the host computer for physical testing, as shown in Figure 5, it can be seen that the sensor can realize the contour perception and temperature measurement of warm objects.

The specific process can be referred to as shown in FIG. 6 .

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims

A flexible temperature sensor array, characterized in that it includes a thermosensitive layer, a flexible substrate and wires, and the thermosensitive layer is arranged on the flexible substrate;

The thermosensitive layer is formed by a number of temperature sensing units arranged at fixed intervals;

The wire is adhered to the flexible substrate according to the set route and connected with the temperature sensing unit;

The temperature sensing unit is prepared from (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid))/carbon nanotube/reduced graphene oxide composite film.
The flexible temperature sensor array according to claim 1, wherein the plurality of temperature sensing units are connected by multiplexing lines.
The flexible temperature sensor array according to claim 1, wherein the plurality of temperature sensing units are arranged in a square array, a rhombus array, a sector array, a circular array or a ring array.
A method for preparing a flexible temperature sensor array according to any one of claims 1-3, characterized in that it comprises the following steps:

Add the modified single-walled carbon nanotubes and reduced graphene oxide into (poly(3,4-ethylenedioxythiophene): poly(styrenesulfonic acid)) aqueous solution, and after dispersing evenly, vacuum filter and dry , to obtain the (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid))/carbon nanotube/reduced graphene oxide composite film;

Cut the (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid))/carbon nanotube/reduced graphene oxide composite film according to the set pattern structure to obtain several temperature sensing units ;

adhering the plurality of temperature sensing units on the flexible substrate at a fixed distance;

adhering the wires on the flexible substrate according to the set route and connecting them with the temperature sensing unit through silver paste to form a multiplexing circuit;

After the silver paste is solidified, it is packaged and dried to obtain the flexible temperature sensor array.
The preparation method of flexible temperature sensor array according to claim 4, is characterized in that, specifically comprises the following steps:

S1. Pickling carbon nanotubes: Take carbon nanotube powder and add it to H 2 SO 4 /H 2 O 2 mixed solution, heat and condense to reflux, after cooling to room temperature, wash with deionized water until the solution becomes neutral, The solution is vacuum filtered and then dried to obtain acid-washed carbon nanotubes;

S2. Preparation of reduced graphene oxide: add graphene oxide powder into water to obtain a dispersed graphene oxide solution, drop a reducing agent into the graphene oxide solution, and obtain a reduced graphene oxide solution through reaction; then the The reduced graphene oxide solution is washed to neutrality, suction filtered and dried to obtain reduced graphene oxide powder;

S3. Prepare a composite solution: add dimethyl sulfoxide solution to the PEDOT:PSS aqueous solution, then add the acid-washed carbon nanotubes described in S1, the reduced graphene oxide powder and dodecylbenzenesulfonate described in S2 sodium bicarbonate powder, stirred and dispersed to obtain a composite solution;

S4. Preparation of composite film: centrifuge the composite solution described in S3, then suction filter, then heat and dry to obtain (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid))/carbon nanotube/ Reduced graphene oxide composite film;

S5. Cutting and forming: cutting the (poly(3,4-ethylenedioxythiophene): poly(styrenesulfonic acid))/carbon nanotube/reduced graphene oxide composite film according to the set graphic structure to obtain A number of temperature sensing units;

S6. Assembling the flexible temperature sensor array: transfer the temperature sensing units cut and formed in S5 to the flexible substrate coated with an adhesive layer, and arrange them at fixed intervals; adhere the wires to the flexible substrate according to the set route on the substrate and connected with the heat-sensitive layer through silver paste to form a multiplexing circuit; after the silver paste is cured, it is packaged and dried to obtain the flexible temperature sensor array.
The method for preparing a flexible temperature sensor array according to claim 5, characterized in that, in the step S1, the ratio of the carbon nanotubes to the H 2 SO 4 /H 2 O 2 mixed solution is (0.01- 0.03)g: (10-30)mL, the H 2 SO 4 /H 2 O 2 mixed solution is a mixture of 100mL 2mol/L sulfuric acid aqueous solution and 30% hydrogen peroxide aqueous solution with a volume ratio of (4-5):1 solution.
The method for preparing a flexible temperature sensor array according to claim 5, characterized in that, in the step S3, (poly(3,4-ethylenedioxythiophene):poly(styrene) with a mass fraction of 1.3 wt% is used. Sulfonic acid)) aqueous solution, the mass ratio of poly(3,4-ethylenedioxythiophene) to poly(styrenesulfonic acid) is 5:8.
The preparation method of flexible temperature sensor array according to claim 5, is characterized in that, in described step S3, the carbon nanotube after acid washing described in the added S1 and the quality of the reduced graphene oxide powder described in S2 The ratio is 1:1.
The preparation method of flexible temperature sensor array according to claim 5, is characterized in that, in described step S3, the addition amount of sodium dodecylbenzenesulfonate powder is the carbon after pickling described in added S1 Nanotubes are 10 times stronger than the reduced graphene oxide powder described in S2.
The method for preparing a flexible temperature sensor array according to claim 5, characterized in that, in the step S5, the mass ratio of the polydimethylsiloxane prepolymer to the curing agent is (9-12):1, And the rotation speed of the spin coating is 1000-2000rpm, and the spin coating time is 5-15s.
The application of flexible temperature sensor array in wearable devices as tactile interactive sensing, wherein the flexible temperature sensor array is the flexible temperature sensor array according to any one of claims 1-3 or according to any one of claims 4-10 A flexible temperature sensor array prepared by one method.