Preparation method of biaxial micro-fold structure strain sensor based on MXene-cys film with high mechanical strength
By using high mechanical strength MXene-cys film to prepare biaxial micro-pleated structure strain sensors, the problem of difficulty in dealing with large deformation in traditional sensors is solved, and the strain sensing performance with high tensile properties and stable response is achieved.
Patent Information
- Application Number
- CN202510117180.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-24
- Publication Date
- 2025-05-09
AI Technical Summary
Traditional sensors are difficult to meet the needs of large deformations or complex deformations, especially in areas such as flexible electronics, wearable devices and software robots.
A high mechanical strength MXene-cys film was used to prepare Ti3C2Tx-MXene solution by selective etching, and L-cysteine cys were added to modify MXene to form a biaxial micro-fold structure strain sensor.
It achieves high tensile properties and good strain sensing performance. The sensor responds to signals stably under high strain conditions, and is suitable for flexible electronic equipment, human health monitoring and human-computer interaction.
Smart Images
Figure CN119955307A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of flexible wearable electronic devices, and specifically relates to a method for preparing a biaxial micro-fold structure strain sensor based on a high mechanical strength MXene-cys film. The flexible strain sensor can be widely used in the fields of human motion monitoring, human-computer interaction, and soft robots due to its light weight, flexibility, and stretchability. Background Art
[0002] With the rise of flexible electronics, wearable devices and soft robots, more and more application scenarios need to cope with large or complex deformations. Traditional sensors may not be able to meet this demand. The core of flexible strain sensors is flexibility and stretchability. Sensors with a wide strain range are key basic components in flexible electronics, which can adapt to more complex application scenarios, such as soft robots, highly flexible wearable devices, dynamic biological tissue monitoring, and equipment monitoring in extreme environments. In this context, it is imperative to develop a flexible strain sensor with good flexibility, good stretchability, and a wide strain range that can monitor large deformations. Summary of the invention
[0003] The present invention provides a method for preparing a high mechanical strength MXene-cys film, and uses the method to prepare a strain sensor having a MXene-cys biaxial micro-corrugated film. The strain sensor based on the crack-free corrugated structure exhibits high stretchability and good strain sensing properties. The preparation method of the present invention is simple and low-cost, and provides the possibility for a wide range of practical applications.
[0004] To achieve the above purpose, the technical solution adopted by the present invention is: a method for preparing a biaxial micro-fold structure strain sensor based on a high mechanical strength MXene-cys film, which is based on acrylic acid VHB 4910 as a base material, MXene-cys as a conductive material, and PDMS as a packaging material, and is obtained by stirring modification, filtration, pre-stretching, dry transfer, and shrinkage.
[0005] The method for preparing a biaxial micro-wrinkle structure strain sensor based on a high mechanical strength MXene-cys film comprises the following steps:
[0006] 1) Preparation of Ti3C2T by selective etching x -MXene solution, and then dilute the solution, stir, and ultrasonically disperse to obtain a Ti3C2T3O4 solution with a concentration of 0.1 mg / mL. x -MXene colloidal solution;
[0007] 2) Add 12.1 mg of L-cysteine cys to the Ti3C2T x-MXene colloidal solution was stirred for 30 min (stirring rate was 300-500 r / min) to obtain a Cys-modified MXene (MXene-cys) solution;
[0008] 3) vacuum filtering the MXene-cys solution obtained in step 2) to obtain a MXene-cys film;
[0009] 4) The acrylic acid VHB 4910 is fixed on a biaxial stretching platform as a substrate, and biaxial pre-stretching is performed in the vertical and horizontal directions in sequence. Then, the MXene-cys film obtained in step 3) is transferred to the substrate by dry transfer, and then the biaxially pre-stretched substrate is released to restore it to its initial state. In this process, the MXene-cys film will form a crack-free biaxial micro-wrinkled structure.
[0010] 5) Using a conductive silver paste, copper electrodes are fixed to both ends of the MXene-cys biaxial micro-corrugated structure film obtained in step 4), and after the conductive silver paste is cured, a biaxial micro-corrugated structure strain sensor based on the MXene-cys film is obtained;
[0011] 6) Using a mixed solution of polydimethylsiloxane (PDMS) and a curing agent (Sylgard 184), the MXene-cys biaxial micro-corrugated structure strain sensor obtained in step 5) is surface packaged to obtain a biaxial micro-corrugated structure flexible strain sensor based on a MXene-cys film.
[0012] Furthermore, in the above-mentioned preparation method, the MXene solution described in step 1) is prepared by chemical etching, centrifugal washing and ultrasonic stripping, and the specific preparation steps are as follows:
[0013] 1.1) Etching reaction: Add 3.2g of lithium fluoride to a polytetrafluoroethylene beaker, then add 40mL of 9mol / L hydrochloric acid, and fully react under the conditions of heating and stirring in a water bath. Then, under stirring in a water bath, add 2g of titanium aluminum carbide (Ti3AlC2-MAX) to the beaker in small amounts in 9 to 10 times, and this process lasts for 20 to 30 minutes. Then, cover the beaker with a lid to seal it, and continue stirring in a constant temperature water bath to perform the etching reaction. After the reaction is completed, centrifuge the solution and discard the supernatant.
[0014] 1.2) Acid washing and water washing: Use hydrochloric acid to remove the unreacted excess lithium fluoride, and then use deionized water to centrifuge the solution for multiple times until the solution is neutral.
[0015] 1.3) Ultrasonic stripping under inert gas protection: Pour the neutral solution into a gas washing bottle, pass inert gas to remove the air in the bottle, seal it, and perform ultrasonic stripping for 0.5 to 1.5 hours. After the ultrasonic stripping is completed, centrifuge again and take the upper liquid as the prepared Ti3C2T x -MXene solution.
[0016] Furthermore, in the above preparation method, in step 1), the stirring time is 10 to 20 min and the stirring speed is 500 to 700 r / min, and the ultrasonic time is 10 to 20 min.
[0017] Furthermore, in the above-mentioned preparation method, in step 1.1), the conditions for sufficient reaction are: the temperature is maintained in the range of 35-45°C, the stirring speed is controlled between 500-700r / min, and the stirring duration is 10-20min; the conditions for the etching reaction are: the reaction temperature is maintained at 35-45°C, the stirring speed is maintained at 500-700r / min, and the stirring time is 23-24h.
[0018] Furthermore, in the above-mentioned preparation method, in step 1.3), the gas flow rate of the inert gas process is controlled between 10 and 12 m / s, and the ventilation time lasts for 0.5 to 1.5 h.
[0019] Furthermore, in the above-mentioned preparation method, in step 3), the MXene-cys film is achieved by the following steps: a 0.1 mg / mL MXene-cys solution (9 to 10 mL) is vacuum filtered to obtain a MXene-cys film.
[0020] Furthermore, in the above-mentioned preparation method, in step 4), the biaxial micro-corrugated structure film is realized by the following steps: after fixing the acrylic VHB 4910 substrate on the pre-stretching platform, pre-stretching it by 200% in the vertical direction and 300% in the horizontal direction, and then dry-transferring the MXene-cys film to the substrate, first releasing the pre-stretching in the horizontal direction and then releasing the pre-stretching in the vertical direction, and waiting for the substrate to completely recover to its initial state, a biaxial micro-corrugated structure film is obtained.
[0021] Furthermore, in the above-mentioned preparation method, in step 5), the curing process is achieved by the following steps: transferring the film with electrode to a blast oven at 50-60°C and curing for 20-30 minutes. After the conductive silver paste is completely cured, a biaxial micro-wrinkled structure strain sensor based on MXene-cys film is obtained.
[0022] Furthermore, in the above-mentioned preparation method, the encapsulation process in step 6) is achieved by the following steps: after preparing a mixed solution with a mass ratio of PDMS and curing agent of 10:1, 1 mL of the mixed solution is slowly dripped on the MXene-cys biaxial micro-corrugated structure film with a dropper, and then cured at 50-60°C for 4-5h to obtain a biaxial micro-corrugated structure flexible strain sensor based on the MXene-cys film.
[0023] The MXene-cys film based on high mechanical strength provided by the present invention is used for a biaxial micro-wrinkle structure strain sensor with high stretchability and good strain sensing performance, and can be applied to flexible electronic devices, human health monitoring and human-computer interaction.
[0024] Compared with the prior art, the present invention has the following beneficial technical effects:
[0025] 1. The present invention prepares a strain sensor with a biaxial micro-wrinkle structure through a simple preparation method. Compared with MXene film, the biaxial micro-wrinkle structure strain sensor based on MXene-cys film exhibits a crack-free micro-wrinkle structure.
[0026] 2. The MXene-cys biaxial micro-corrugated structure strain sensor based on high mechanical strength prepared by the present invention benefits from its crack-free micro-corrugated structure. The sensor exhibits ultra-high stretchability. Even under extreme conditions of high strain, the response signal of the sensor remains stable, ensuring stable output of performance.
[0027] 3. The MXene-cys biaxial micro-wrinkle structure strain sensor based on high mechanical strength prepared by the present invention will greatly increase its compatibility in the field of flexible electronic devices and wearable devices due to its good strain sensing performance. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 The raw materials Ti3AlC2-MAX and Ti3C2T in Example 1 x -XRD comparison chart of MXene nanosheets.
[0029] Figure 2 This is a SEM image of the biaxial micro-wrinkle structure strain sensor of Example 1;
[0030] Among them, a: biaxial micro-wrinkle morphology based on MXene film; b: biaxial micro-wrinkle morphology based on MXene-cys film.
[0031] Figure 3 This is a strain sensing characteristic diagram of a biaxial micro-wrinkle structure strain sensor based on a high mechanical strength MXene-cys film prepared in Example 1. DETAILED DESCRIPTION
[0032] Example 1
[0033] (I) The preparation method of the biaxial micro-wrinkle structure strain sensor based on the high mechanical strength MXene-cys film is as follows:
[0034] 1. Preparation of Ti3C2T by selective etching x -MXene solution, the specific preparation steps are as follows:
[0035] 1.1) Etching reaction: Add 3.2g of lithium fluoride to a polytetrafluoroethylene beaker, then add 40mL of 9mol / L hydrochloric acid, and fully react under heating and stirring in a water bath. The temperature is maintained in the range of 35-45°C, the stirring speed is controlled between 500-700r / min, and the stirring time is 10-20min. Then, under stirring in a water bath, 2g of titanium aluminum carbide (Ti3AlC2-MAX) is gradually and slowly added to the beaker in small amounts in 9-10 times, and this process lasts for 20-30min. Then, cover the beaker lid and seal it, and continue stirring in a constant temperature water bath for etching reaction. The reaction temperature is maintained at 35-45°C, the stirring speed is maintained at 500-700r / min, and the stirring time is 23-24h. After the reaction is completed, the solution is centrifuged and the supernatant is discarded.
[0036] 1.2) Acid washing and water washing: Use hydrochloric acid to remove the unreacted excess lithium fluoride, and then use deionized water to centrifuge the solution for multiple times until the solution is neutral.
[0037] 1.3) Ultrasonic stripping under inert gas protection: Pour the neutral solution into a washing bottle, pass inert gas to remove the air in the bottle, seal it, and perform ultrasonic stripping for 0.5 to 1.5 hours. After the ultrasonic stripping is completed, centrifuge again, and take the upper liquid as the prepared MXene solution. Then dilute the MXene solution, stir it for 10 to 20 minutes, and ultrasonicate it for 10 to 20 minutes to obtain a Ti3C2T3O ... x -MXene colloidal solution;
[0038] 2. Add 12.1 mg of L-cysteine cys to the MXene colloidal solution and stir for 30 min (stirring rate is 300-500 r / min) to obtain a cys-modified MXene (MXene-cys) solution;
[0039] 3. After vacuum filtration of 0.1 mg / mL MXene-cys solution (9-10 mL), a MXene-cys film was obtained;
[0040] 4. Fix the acrylic acid VHB 4910 as a substrate on a biaxial stretching platform, and pre-stretch it by 200% in the vertical direction and 300% in the horizontal direction. Then transfer the MXene-cys film to the substrate by dry transfer, and then release the biaxially pre-stretched substrate in the horizontal and vertical directions to restore it to its initial state. In this process, the MXene-cys film will form a crack-free biaxial micro-wrinkle structure.
[0041] 5. Use conductive silver paste to fix copper electrodes at both ends of the MXene-cys biaxial micro-corrugated structure film. The film with electrodes is cured in a blast oven at 50-60°C for 20-30 minutes to obtain a biaxial micro-corrugated structure strain sensor based on MXene-cys film after the conductive silver paste is cured.
[0042] 6. Use a dropper to take 1 mL of a mixed solution of polydimethylsiloxane (PDMS) and curing agent (Sylgard 184) (the mass ratio of PDMS to curing agent is 10:1) and slowly drip it on the surface of the MXene-cys biaxial micro-corrugated structure strain sensor for protection and packaging and cure it at 50-60°C for 4-5 hours to obtain a biaxial micro-corrugated structure flexible strain sensor based on MXene-cys film.
[0043] (II) Characterization
[0044] Figure 1 XRD comparison diagram of Example 1, which includes raw materials Ti3AlC2-MAX and Ti3C2T x -MXene nanosheets, it can be seen that Ti3C2T x -MXene's XRD spectrum shows that the diffraction peak of the (104) crystal plane disappears at the 38.85° position, indicating that the Al element of the raw material Ti3AlC2-MAX is successfully selectively etched by hydrofluoric acid (HF), and the (002) crystal plane moves forward from 9.6° to 7.1°, indicating that the interlayer spacing of MXene increases and a single-layer MXene nanosheet is successfully prepared.
[0045] Figure 2 The SEM image of the biaxial micro-wrinkle structure strain sensor of Example 1; wherein a is the morphology of the biaxial micro-wrinkles based on the MXene film; b is the morphology of the biaxial micro-wrinkles based on the MXene-cys film. The surface micro-morphology of the biaxial micro-wrinkle structure strain sensor was characterized by scanning electron microscopy. Figure 2 As shown in a, it can be seen that the MXene film on its surface is broken due to its weak mechanical strength and does not form a complete wrinkle structure, such as Figure 2As shown in (b), it can be observed that the MXene-cys film forms a complete biaxial micro-wrinkled structure without cracks, which is mainly due to the fact that the mechanical strength of the MXene film is enhanced after L-cysteine modification of MXene.
[0046] Figure 3 The strain sensing characteristic diagram of a biaxial micro-corrugated structure strain sensor based on a high mechanical strength MXene-cys film prepared in Example 1. The resistance of the biaxial micro-corrugated structure strain sensor based on the MXene-cys film was tested using a digital multimeter and the resistance under different strains was recorded. Figure 3 As shown, the strain range is 300%, in the strain range of 0-190%, GF=0.66, in the strain range of 190-240%, GF=1.95, in the strain range of 240-280%, GF=100.0, in the strain range of 280-300%, GF=892.5.
Claims
1. A MXene-cys film with high mechanical strength for a biaxial micro-wrinkled structure strain sensor, characterized in that: It is made of acrylic acid VHB 4910 as the base material, MXene-cys as the conductive material, and PDMS as the packaging material, and is obtained through modification, pre-stretching, dry transfer, and shrinkage.
2. The method for preparing a biaxial micro-wrinkled structure strain sensor based on a high mechanical strength MXene-cys film according to claim 1, characterized in that: The preparation method is carried out according to the following steps: 1) Preparation of Ti3C2T by selective etching x -MXene solution, and then dilute the solution, stir, and ultrasonically disperse to obtain a Ti3C2T3O4 solution with a concentration of 0.1 mg / mL. x -MXene colloidal solution; 2) Add L-cysteine cys to Ti3C2T x -MXene colloidal solution was stirred for 30 min at a stirring rate of 300-500 r / min to obtain a cys-modified MXene solution, i.e., a MXene-cys solution; 3) After vacuum filtration of the MXene-cys solution, a MXene-cys film is obtained; 4) The acrylic acid VHB 4910 is fixed on a biaxial stretching platform as a substrate, and biaxial pre-stretching is performed in the vertical and horizontal directions in sequence, and then the MXene-cys film is transferred to the substrate by dry transfer, and then the biaxially pre-stretched substrate is released to restore it to its initial state. In this process, the MXene-cys film will form a crack-free biaxial micro-wrinkled structure; 5) Using conductive silver paste to fix copper electrodes at both ends of the film with a biaxial micro-corrugated structure of MXene-cys, after the conductive silver paste is cured, a biaxial micro-corrugated structure strain sensor based on the MXene-cys film is obtained; 6) The MXene-cys biaxial micro-corrugated structure strain sensor was surface encapsulated using a mixed solution of polydimethylsiloxane (PDMS) and curing agent Sylgard 184 to obtain a biaxial micro-corrugated structure flexible strain sensor based on the MXene-cys film.
3. The preparation method according to claim 2, characterized in that: Ti3C2T described in step 1) x -MXene solution is prepared by chemical etching, centrifugal washing and ultrasonic stripping. The specific preparation steps are as follows: 1.1) Etching reaction: lithium fluoride is added to a polytetrafluoroethylene beaker, followed by hydrochloric acid, which is fully reacted under the conditions of heating and stirring in a water bath, and then titanium aluminum carbide Ti3AlC2-MAX is gradually added in small amounts in 9 to 10 times under stirring in a water bath, and this process lasts for 20 to 30 minutes, and then the beaker is sealed and continued to stir in a constant temperature water bath for etching reaction. After the reaction is completed, the solution is centrifuged and the supernatant is discarded; 1.2) Acid washing and water washing: Use hydrochloric acid to remove the unreacted excess lithium fluoride, and then use deionized water to centrifuge the solution several times until the solution is neutral; 1.3) Ultrasonic stripping under inert gas protection: Pour the neutral solution into a gas washing bottle, introduce inert gas to remove the air in the bottle, and then seal it. Perform ultrasonic stripping for 0.5 to 1.5 hours. After the ultrasonic stripping is completed, centrifuge again and take the upper liquid as the prepared Ti3C2T x -MXene solution.
4. The preparation method according to claim 2, characterized in that: The stirring time in step 1) is 10 to 20 minutes, the stirring speed is 500 to 700 r / min, and the ultrasonic time is 10 to 20 minutes.
5. The preparation method according to claim 3, characterized in that: In step 1.1), the conditions for the full reaction are: the temperature is maintained in the range of 35 to 45°C, the stirring speed is controlled between 500 and 700 r / min, and the stirring duration is 10 to 20 min; the conditions for the etching reaction are: the reaction temperature is maintained at 35 to 45°C, the stirring speed is maintained at 500 to 700 r / min, and the stirring time is 23 to 24 h.
6. The preparation method according to claim 3, characterized in that: In step 1.3), the gas flow rate of the inert gas process is controlled between 10 and 12 m / s, and the ventilation time lasts for 0.5 to 1.5 h.
7. The preparation method according to claim 2, characterized in that: In step 3), the MXene-cys film is obtained by the following steps: 9 to 10 mL of 0.1 mg / mL MXene-cys solution is vacuum filtered to obtain a MXene-cys film.
8. The preparation method according to claim 2, characterized in that: In step 4), the biaxial micro-corrugated structure film is achieved by the following steps: after fixing the acrylic VHB 4910 substrate on the pre-stretching platform, pre-stretching it by 200% in the vertical direction and 300% in the horizontal direction, and then dry-transferring the MXene-cys film to the substrate, first releasing the pre-stretching in the horizontal direction and then releasing the pre-stretching in the vertical direction, and after the substrate is completely restored to its initial state, a biaxial micro-corrugated structure film is obtained.
9. The preparation method according to claim 2, characterized in that: In step 5), the curing process is achieved by the following steps: transferring the film with electrodes to a blast oven at 50-60°C and curing for 20-30 minutes. After the conductive silver paste is completely cured, a biaxial micro-wrinkled structure strain sensor based on the MXene-cys film is obtained.
10. The preparation method according to claim 2, characterized in that: The encapsulation process in step 6) is achieved through the following steps: after preparing a mixed solution with a mass ratio of PDMS and curing agent of 10:1, 1 mL of the mixed solution is slowly dripped on the MXene-cys biaxial micro-corrugated structure film with a dropper, and then cured at 50-60°C for 4-5h to obtain a biaxial micro-corrugated structure flexible strain sensor based on the MXene-cys film.