Method for inducing graphene by utilizing laser ablation partitioned doped film and application

Abstract

The invention discloses a method for inducing graphene by utilizing a laser ablation partition doped film and application. The method comprises the following steps: preparing different sensitive material solutions; pouring different sensitive material solutions on a substrate, and performing blade coating; slowly placing the scraped solution in a drying oven, and annealing to obtain a flexible film doped with different sensitive materials; preparing a plurality of different flexible films doped with different sensitive materials according to the same method; the method comprises the following steps: reasonably trimming and fixedly splicing different flexible films doped with different sensitive materials, dispensing a small amount of PAA glue at the splicing edge, standing, and putting into an oven for secondary annealing to obtain a flexible composite film doped in different regions; a femtosecond laser processing system is used, and according to a CAD model of a specific pattern, graphene is directly written and induced in different areas of the surface of the flexible composite film doped in the partitioned mode. According to the method, different regions are specifically functionalized, and graphene is induced by laser ablation, so that the multi-mode graphene sensor is prepared.

Description

Technical Field

[0001] The present invention relates to the field of multimodal perception, and in particular to a method and application for inducing graphene by laser ablation zone doping thin films. Background Art

[0002] Sensors can convert various chemical signals and physiological signals into electrical signals, which is a major focus of current research in the electronics field. Integrating multiple sensors is a major trend in the current development of sensors. Flexible sensors are widely studied currently. For example, on the human skin, flexible sensors are convenient for detecting external multi-stimuli in various environments, including non-planar and shape-changing objects, etc. However, to obtain multiple physiological signals from the skin, a single sensor cannot meet the requirement, and multimodal sensors need to be used to obtain multiple signals in order to obtain more comprehensive and accurate physiological information.

[0003] Current multimodal sensors mainly focus on material research and development, structural design and integration, signal processing and decoupling. In terms of material research and development, new multifunctional materials are developed, such as materials that are sensitive to multiple physical quantities such as pressure, temperature, humidity, etc. and can produce distinguishable signal outputs to achieve multimodal perception. In terms of structural design, integrated integrated structures and sensor array integration methods such as planar and stacked types are studied, manufacturing technologies or patterning methods with low cost and scalable preparation are developed, and at the same time, through structural designs such as wrinkled, island-bridge, and serpentine lines, an integrated flexible multimodal structure is explored to achieve crosstalk-free perception of multiple parameters such as pressure and temperature. In terms of signal processing and decoupling, the differences in signals in terms of time, frequency, etc. and multi-signal collaborative processing methods are used to effectively decouple different modal signals and improve the accuracy and reliability of signal output.

[0004] With the increase in sensing modes, relying solely on a single sensing mechanism will inevitably cause overlap and interference between different sensing signals. How to achieve the induction and differentiation of multiple stimuli in a single sensor has always been a current technical bottleneck. Zhao Shuai and Zhu Rong from Tsinghua University were inspired by the human thermal sensation and prepared a multifunctional electronic skin. A thermosensitive platinum film was deposited on a flexible polyimide substrate to form a sensing unit with multiple sensing functions. The thermal film element realizes the perception of pressure, substances, and wind speed and direction through heat conduction and heat convection, and the cold film element is used to measure the ambient temperature. It integrates multiple sensing functions and has broad application prospects in fields such as skin repair, robotics, and health monitoring. Li Qiushi et al. fabricated a pressure-strain flexible graphene sensor with a 3D microstructure by laser-induced generation of graphene (LIG) on a 3D-printed polyetheretherketone corrugated substrate. Pressure and strain will directly change the contact state of graphene, thereby affecting the resistance value of the sensor. On this basis, two integrated piezoresistive sensors were developed to monitor precise strain and pressure signals. Guo Hongshuang et al. designed a zwitterionic skin sensor that can continuously monitor and distinguish three-stimulus response information in real time. The sandwich-structured sensor system is based on a zwitterionic-glucose-sensitive skin-like hydrogel, and there is an isolation elastomer layer between its upper and lower layers, which can monitor and distinguish three signals of pressure, temperature, and glucose concentration without signal interference, effectively promoting the healing of diabetic wounds.

[0005] In summary, the innovation of multimodal sensing for detecting multiple signals is mainly carried out from aspects such as structural design and material selection. Although there are related studies on preparing multimodal sensors with laser-induced graphene, the research on preparing multimodal sensing by preparing a partition-doped flexible thin film and then directly writing sensitive areas by laser has not been published.

[0006] Current drawbacks in the preparation of flexible thin films: (1) Single doping: The current preparation of flexible thin films is mainly for single materials or a mixture of multiple materials doped. The prepared thin film materials are uniformly mixed and single, and the functionalization on the same thin film is unique. (2) Complicated preparation steps: Taking the preparation of flexible electronic thin films by chemical vapor deposition as an example, it requires multiple steps such as substrate pretreatment, gas introduction for reaction, thin film growth, and post-treatment. Each step requires strict parameter control, and any deviation may affect the quality of the thin film. For example, if the substrate treatment is not thorough, it will reduce the adhesion between the thin film and the substrate.

[0007] Disadvantages of current multi-modal sensor fabrication: (1) High fabrication cost: To achieve multi-modal sensing, multiple materials need to be integrated. For example, to fabricate a multi-modal sensor with visual and tactile sensing capabilities, high-quality optoelectronic materials are required to realize the visual function, and piezoelectric or piezoresistive materials sensitive to pressure are used to achieve the tactile function. These special materials are expensive in themselves, and the processing and integration costs of these materials are also high. (2) Low reliability: A multi-modal sensor contains multiple functional modules, and a failure in any one module may affect the performance of the entire sensor. For example, in a multi-modal sensor integrating visual and gas detection functions, if the gas-sensitive element in the gas detection module fails, it will not only result in the loss of gas detection function but may also affect the overall decision-making result based on multi-modal data fusion. (3) Size limitation: In many application scenarios, especially in the fields of wearable devices and small robots, the size requirements for sensors are extremely strict. However, integrating multiple modal sensing functions means integrating multiple sensor components in a limited space, which will increase the size of the sensor and make it difficult to meet the requirements of miniaturization. Summary of the Invention

[0008] Aiming at the disadvantages of current flexible film fabrication and multi-modal sensor fabrication, the present invention provides a method and application for inducing graphene by laser ablation of regionally doped films, which specifically functionalizes different regions and then induces graphene by laser ablation to fabricate a multi-modal graphene sensor.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] In an embodiment of the present invention, a method and application for inducing graphene by laser ablation of regionally doped films are proposed, and the method includes:

[0011] Mix polyimide with different sensitive materials and stir well to make different sensitive material solutions;

[0012] Slowly pour the different sensitive material solutions onto the substrate and use a doctor blade to scrape and coat;

[0013] Slowly place the scrape-coated different sensitive material solutions in an oven, and after annealing, obtain flexible films doped with different sensitive materials;

[0014] Prepare a variety of different flexible films doped with different sensitive materials according to the above same method;

[0015] Reasonably trim the different flexible films doped with different sensitive materials, then fix and splice them, drop a small amount of PAA glue at the splicing edge, let it stand, and then put it into an oven for secondary annealing to obtain a regionally doped flexible composite film;

[0016] Using a femtosecond laser processing system, graphene is directly written and induced at different regions on the surface of a flexibly composite film with zoned doping according to the CAD model of a specific pattern.

[0017] Furthermore, the femtosecond laser processing system includes: a femtosecond laser light source module, an optical path module, an imaging module, a processing module, and a computer control system; the femtosecond laser light source module is used to generate laser pulses of 10 -15 s; the optical path module is used to determine the laser transmission path and transmit the laser to the processing area; the imaging module is used to present a clear image; the processing module is used to place and move the processed sample; the computer control system is used to set the parameters of the femtosecond laser and plan the laser direct writing path according to the imported CAD model of the specific pattern.

[0018] Furthermore, the optical path module includes an electrically controlled shutter, a polarization beam splitter, an optical isolator, an aperture stop, and a mirror.

[0019] Furthermore, the processing module includes a three-axis gas translation stage, and precise displacement control is performed through the computer control system to enable different parts of the sample to receive laser processing in sequence.

[0020] Furthermore, the application of using laser ablation of zoned doped films to induce graphene in the preparation of multimodal graphene sensors is provided.

[0021] Beneficial effects:

[0022] 1. Compared with the flexibly thin films prepared by doping with traditional single sensitive materials, the flexibly composite film with zoned doping integrates different sensitive materials on the same flexibly thin film according to requirements, functionalizes each unit specifically, and has the characteristics of high integration, simple structure, small interference between functional regions, and better wearability.

[0023] 2. Due to its ultrashort pulse duration (10 -15 s) and ultrahigh instantaneous peak power (10 14 W / cm 2 ), femtosecond laser can directly write and induce graphene on the polyimide doped with sensitive materials according to specific patterning design, and then prepare multimodal graphene sensors. Description of the Drawings

[0024] Figure 1 is the flowchart of the method for inducing graphene by laser ablation of zoned doped films in the present invention;

[0025] Figure 2 is the architecture diagram of the femtosecond laser direct writing processing system in the present invention;

[0026] In the figure: 1 - femtosecond laser light source module, 101 - femtosecond laser, 102 - laser power supply, 2 - optical path module, 201 - electronically controlled shutter, 202 - polarization beam splitter, 203 - optical isolator, 204 - first aperture diaphragm, 205 - second aperture diaphragm, 206 - first mirror, 207 - second mirror, 208 - third aperture diaphragm, 209 - fourth aperture diaphragm, 3 - imaging module, 301 - illumination light source, 302 - focusing lens, 303 - CCD imaging unit, 4 - processing module, 401 - three-axis gas translation stage, 5 - computer control system;

[0027] Figure 3 It is a schematic diagram of the present invention using laser ablation to process a 2×2 partition-doped flexible composite film. Specific embodiments

[0028] The principles and spirit of the present invention will be described below with reference to several exemplary embodiments. It should be understood that these embodiments are provided only to enable those skilled in the art to better understand and then design the present invention, rather than limiting the scope of the present invention in any way. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to be able to fully convey the scope of the present disclosure to those skilled in the art.

[0029] Those skilled in the art know that the embodiments of the present invention can be designed as a device, apparatus, equipment, method, or computer program product. Therefore, the present disclosure can be specifically designed in the following forms: completely hardware, completely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software.

[0030] According to the embodiments of the present invention, a method and application for inducing graphene by laser ablation of partition-doped thin films are proposed. Different regions are specifically functionalized, and then graphene is induced by laser ablation, and then a multimodal graphene sensor is prepared.

[0031] The principles and spirit of the present invention will be elaborated below with reference to several representative embodiments of the present invention.

[0032] The overall solution adopted by the present invention includes two parts: the preparation of a partition-doped flexible composite film and the induction of graphene by laser ablation of the partition-doped thin film.

[0033] 1. Preparation of partition-doped flexible composite film

[0034] (1) As Figure 1 shown, polyimide (PAA) is mixed with different sensitive materials in a certain mass ratio and stirred evenly to form different sensitive material solutions; different sensitive materials include various two-dimensional materials, MOF, metal nanoparticles, metal oxides, etc.;

[0035] (2) Slowly pour different sensitive material solutions onto the substrate, set the scraping parameters of the scraping machine (including a scraping thickness of 1.3 mm and a scraping speed of 10 mm / s), and perform scraping;

[0036] (3) Slowly place the scraped different sensitive material solutions in an oven, anneal for 2.5 h to obtain flexible films doped with different sensitive materials;

[0037] (4) Prepare a variety of flexible films doped with different sensitive materials according to the same method described above;

[0038] (5) Reasonably trim different flexible films doped with different sensitive materials, then fix and join them according to their actual application requirements. Drop a small amount of PAA glue at the splicing edge, let it stand for 30 min, and put it into the oven for secondary annealing for 2.5 h to obtain a flexible composite film with zoned doping;

[0039] 2. Induce graphene using a laser-ablated zoned-doped film

[0040] Use a femtosecond laser processing system as shown in Figure 2 Set the processing power to 600 mW and the scanning speed to 5 mm / s. According to the CAD model of a specific pattern (draw a CAD graph according to the size of the flexible composite film with zoned doping and combined with the actual application requirements), the femtosecond laser uses the characteristics of ultrashort pulses and ultra-high peak power to directly write and induce graphene in different regions on the surface of the flexible composite film with zoned doping. As shown in Figure 3 As shown, the four rectangular blocks 1-4 are regional units doped with different sensitive materials, and these four rectangular blocks form a 2*2 flexible composite film with zoned doping. The femtosecond laser processing system performs laser processing on these four rectangular block regions at one time.

[0041] As shown in Figure 2 As shown, the femtosecond laser processing system includes: a femtosecond laser light source module 1, an optical path module 2, an imaging module 3, a processing module 4, and a computer control system 5; the femtosecond laser light source module 1 includes a femtosecond laser 101 and a laser power supply 102, which are used to generate 10 -15The laser pulses of femtoseconds; the optical path module 2 includes an electrically controlled shutter 201, a polarization beam splitter 202, an optical isolator 203, a first aperture stop 204, a second aperture stop 205, a first mirror 206, a second mirror 207, a third aperture stop 208 and a fourth aperture stop 209, which are used to determine the laser transmission path and transmit the laser to the processing area; the imaging module 3 includes an illumination light source 301, a focusing lens 302 and a CCD imaging unit 303, which are used to present a clear object image; the processing module 4 includes a three-axis gas translation stage 401, which is used to place and move the processing sample, and precise displacement control is performed through the computer control system 5, so that different parts of the sample are sequentially subjected to laser processing; the computer control system 5 is used to set the parameters of the femtosecond laser and plan the laser direct writing path according to the imported CAD model of a specific pattern.

[0042] It should be noted that although the operations of the method of the present invention are described in a specific order in the above embodiments and accompanying drawings, however, this does not require or imply that these operations must be performed in this specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step for execution, and / or one step may be decomposed into multiple steps for execution.

[0043] The method and application for inducing graphene by using laser ablation to dope a thin film in a partitioned manner proposed by the present invention have the following advantages:

[0044] 1. Compared with the flexible thin film prepared by doping with traditional single sensitive materials, the flexible composite thin film doped in a partitioned manner integrates different sensitive materials on the same flexible thin film according to requirements, specific functions of each unit are realized, and it has the characteristics of high integration, simple structure, small interference between functional regions, and better wearability.

[0045] 2. Because femtosecond laser has an ultra-short pulse time (10 -15 s) and an ultra-high instantaneous peak power (10 14 W / cm 2 ), it can directly write and induce graphene on the polyimide doped with sensitive materials according to a specific patterning design, and then prepare a multimodal graphene sensor.

[0046] Although the spirit and principle of the present invention have been described with reference to several specific embodiments, it should be understood that the present invention is not limited to the specific embodiments disclosed, and the division of each aspect does not mean that the features in these aspects cannot be combined for benefit. This division is only for the convenience of expression. The present invention aims to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0047] Regarding the limitations on the scope of protection of the present invention, those skilled in the art should understand that, based on the technical solution of the present invention, various modifications or deformations that can be made by those skilled in the art without creative efforts are still within the scope of protection of the present invention.

Claims

1. A method and application of inducing graphene by laser ablation of partitioned doped thin films, characterized in that: The method includes: Mixing polyimide with different sensitive materials and stirring them evenly to prepare solutions of different sensitive materials; Slowly pour different sensitive material solutions onto the substrate and apply them using a doctor blade coater; The coated solutions of different sensitive materials are slowly placed in an oven, and after annealing, flexible films doped with different sensitive materials are obtained; A variety of flexible films doped with different sensitive materials were prepared according to the same method as above; The flexible films doped with different sensitive materials are trimmed reasonably, fixed and spliced, a small amount of PAA glue is dripped on the splicing edge, and after standing, they are placed in an oven for secondary annealing to obtain a zoned doped flexible composite film; Using a femtosecond laser processing system, graphene is induced by direct writing in different areas on the surface of the partitioned doped flexible composite film according to the CAD model of a specific pattern.

2. The method and application of inducing graphene by laser ablation of a partitioned doped thin film according to claim 1, characterized in that: The femtosecond laser processing system comprises: a femtosecond laser light source module, an optical path module, an imaging module, a processing module and a computer control system; the femtosecond laser light source module is used to generate 10 -15 s laser pulse; the optical path module is used to determine the laser transmission path so that the laser is transmitted to the processing area; the imaging module is used to present a clear object image; the processing module is used to place and move the processing sample; the computer control system is used to set the parameters of the femtosecond laser and plan the laser direct writing path according to the imported CAD model of the specific pattern.

3. The method and application of inducing graphene by laser ablation of a partitioned doped thin film according to claim 2, characterized in that: The optical path module includes an electrically controlled shutter, a polarization beam splitter, an optical isolator, an aperture stop and a reflector.

4. The method and application of inducing graphene by laser ablation of a partitioned doped thin film according to claim 2, characterized in that: The processing module includes a three-axis gas translation stage, which performs precise displacement control through a computer control system so that different parts of the sample can be processed by laser in sequence.

5. The method and application of inducing graphene by laser ablation of a partitioned doped thin film according to claim 1, characterized in that: Application of laser ablation of partitioned doped thin films to induce graphene in the preparation of multimodal graphene sensors.

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