Laser-induced graphene-based sensor preparation device and preparation method

Abstract

The invention relates to the field of flexible sensor preparation, and particularly discloses a laser-induced graphene-based sensor preparation device and method, and the device comprises a base, a detachable packaging groove, a rolling mechanism, a feeding groove and a temperature control system; the rolling mechanism comprises a guide rail, a roller capable of reciprocating along the guide rail and a lifting assembly used for adjusting the height of the roller. The feed trough translates with the drum and feeds flexible substrate material thereto. The preparation method comprises the following steps: paving and pre-curing a first layer of PDMS substrate; a graphene sensing element generated by laser induction is positioned on the graphene substrate; paving a second layer of PDMS to form a sandwich structure and pre-curing; a roller is controlled to perform reciprocating rolling on the sandwich structure, a temperature control system performs dynamic temperature adjustment, PDMS is driven to permeate into graphene three-dimensional pores, and finally complete curing is performed. According to the application, mechanical interlocking combination of PDMS and a graphene network is realized through roller pressurization, and the interface bonding strength and the durability of the sensor are improved.

Description

Technical Field

[0001] This application relates to the field of flexible sensor fabrication, and in particular to a laser-induced graphene-based sensor fabrication apparatus and method. Background Technology

[0002] Flexible strain sensors, as key components of wearable devices and health monitoring systems, have shown broad application prospects in recent years in fields such as human motion capture, physiological signal monitoring, and soft robotics. Their performance hinges on the bonding quality between the sensing layer and the flexible substrate, directly affecting the sensor's reliability, durability, and lifespan. Graphene, due to its excellent conductivity, mechanical strength, and flexibility, has become an ideal material for fabricating high-performance flexible sensors. In particular, laser-induced graphene technology, which directly generates three-dimensional porous graphene structures by laser irradiation of carbon-containing precursors (such as polyimide), offers advantages such as rapid prototyping, controllable patterning, and environmental friendliness, providing a new technological path for constructing high-performance flexible sensors.

[0003] However, existing flexible sensors based on laser-induced graphene still have shortcomings in packaging technology. Traditional methods typically employ a "layered stacking + external encapsulation" approach, sandwiching the graphene sensing layer between two flexible substrates, such as polydimethylsiloxane (PDMS). Due to the weak interfacial bonding between graphene and PDMS, shear stress concentration easily occurs at the interface under long-term cyclic strain, leading to localized delamination of the sensing layer or the propagation of microcracks, affecting the sensor's signal stability and lifespan. Therefore, improving the interfacial bonding strength between the graphene sensing layer and the flexible substrate is a technical problem that needs to be solved in this field. Summary of the Invention

[0004] To address the issue of insufficient interfacial bonding strength between the graphene sensing layer and the flexible substrate, this application provides a laser-induced graphene-based sensor fabrication apparatus and method.

[0005] The laser-induced graphene-based sensor fabrication device provided in this application adopts the following technical solution: A laser-induced graphene-based sensor fabrication apparatus, comprising: Base; A packaging slot, detachably mounted on the base, is used to hold and shape flexible substrate material; The rolling mechanism includes a horizontally arranged guide rail and a roller that reciprocates along the guide rail. The roller is rolled above the encapsulation groove to coat the flexible substrate material into the encapsulation groove and apply pressure to the flexible substrate material in the encapsulation groove. It also includes a lifting assembly to drive the roller to lift and lower, so as to adjust the distance between the roller and the bottom surface of the encapsulation groove. A feeding trough, disposed above the roller and configured to translate with the roller, is used to coat the surface of the roller with a flexible substrate material; The temperature control system includes a base temperature control component and a roller temperature control component. The base temperature control component is used to adjust the temperature of the flexible substrate material in the packaging groove in zones, and the roller temperature control component is used to adjust the temperature of the roller surface.

[0006] This device, through the reciprocating rolling of rollers under controllable pressure, not only achieves automatic and uniform coating and precise thickness control of flexible substrate materials, but also applies continuous and uniform pressure to the semi-cured "flexible substrate-graphene-flexible substrate" sandwich structure during the encapsulation process. During this process, the temperature control system dynamically regulates the rheological behavior of the flexible substrate, driving the flexible substrate to penetrate deep into the pores of the three-dimensional graphene network, forming a strong mechanical interlocking structure. Furthermore, dynamic thermal regulation quickly fixes the shape of the flexible substrate after rolling, thereby significantly improving the interfacial bonding strength between the sensing layer and the encapsulation layer, improving the problems of local peeling and microcrack propagation of the sensing layer, and thus improving the signal stability of the sensor and extending its service life.

[0007] Furthermore, the bottom surface of the feeding trough is provided with an elongated hole, and the axis of the roller is parallel to the elongated hole and the two are located in the same vertical plane.

[0008] The elongated holes enable the flexible substrate prepolymer solution to be continuously and uniformly coated onto the roller surface, ensuring that the flexible substrate prepolymer solution can be transferred to the encapsulation tank at a stable flow rate during the roller rolling process. This improves the problems of flow interruption or uneven thickness that may occur in traditional casting methods, and ensures the uniformity and quality of the laid substrate film.

[0009] Furthermore, a silicone layer is fixedly disposed on the outer periphery of the roller, and the flexible substrate material is polydimethylsiloxane.

[0010] The silicone layer has a certain degree of elasticity and flexibility, which can adaptively conform to the substrate surface during rolling. This not only applies pressure evenly but also avoids the risk of damage to brittle graphene sensing elements that may occur with rigid rollers. At the same time, PDMS and silicone rollers have good material compatibility and are not prone to sticking, ensuring a smooth rolling process and high-quality encapsulation interface.

[0011] Furthermore, two collection slots are fixedly provided on the base, and the two collection slots are located at both ends of the roller translation path, respectively, for recycling excess flexible substrate material in the encapsulation slot.

[0012] The collection tank can collect and recycle excess PDMS solution squeezed out from both ends of the encapsulation tank during the reciprocating motion of the roller, reducing material waste and pollution to equipment and the working environment.

[0013] Furthermore, a baffle is provided between the collection tank and the packaging tank, and the horizontal plane of the upper end surface of the baffle is tangent to the arc surface of the roller. The baffle is configured to rise and fall synchronously with the roller.

[0014] The distance between the bottom surface of the encapsulation tank and the roller determines the liquid level of the flexible substrate material in the encapsulation tank. The horizontal plane of the upper end of the baffle is tangent to the arc surface of the roller, that is, the upper end of the baffle and the lowest point of the roller are on the same horizontal plane, so that the upper end of the baffle can always be flush with the preset liquid level of the flexible substrate material determined by the height of the roller, ensuring that excess material can overflow smoothly into the collection tank.

[0015] By synchronously raising and lowering the rollers and baffles, it is ensured that no matter how the target substrate thickness required by the process changes, the baffles can form an overflow weir that matches the current substrate liquid level. This not only effectively guides the excess flexible substrate material generated by the roller extrusion to the collection tank, effectively preventing overload of materials in the packaging tank, but also provides a stable and consistent rolling action surface for the rollers by precisely controlling the liquid level, thereby ensuring the accuracy of the thickness of each substrate layer and the consistency of batch products.

[0016] Furthermore, the rolling mechanism also includes a pressure sensor for detecting the pressure applied by the roller to the flexible substrate material in the encapsulation groove.

[0017] The pressure sensor enables real-time and accurate monitoring of the pressure applied to the roller, ensuring that the pressure value of each rolling operation is stable and meets the process requirements, thereby improving the repeatability of the process and the quality control of the preparation process.

[0018] This application also provides a method for preparing a laser-induced graphene-based sensor, which employs a laser-induced graphene-based sensor preparation device and includes the following steps: First layer substrate laying and pre-curing: Inject flexible substrate prepolymer solution into the feeding tank, lay the first layer substrate into the encapsulation tank by controlling the roller to roll, and then pre-cur the first layer substrate; Fabrication of graphene sensing element: A graphene sensing element is generated on the surface of a carbon-containing precursor film by laser induction, and wires are connected to both ends of the graphene sensing element; the graphene sensing element is positioned on the surface of the first pre-cured substrate. Second layer substrate installation and pre-curing: A flexible substrate prepolymer solution is injected into the feeding tank. By controlling the roller to roll, a second layer substrate is coated on the graphene sensing element to form a sandwich structure. Then, the second layer substrate is pre-cured. Rolling and complete curing: The roller is controlled to reciprocate and pressurize the pre-cured sandwich structure with a preset pressure. The temperature control components of the base and the roller are dynamically adjusted to allow the flexible substrate material to penetrate into the three-dimensional pores of the graphene sensing element. The pressurized sandwich structure is then completely cured to obtain a laser-induced graphene-based sensor.

[0019] This method systematically integrates key steps such as substrate laying, pre-curing, and rolling pressurization, achieving integrated molding of the "PDMS-graphene-PDMS" sandwich structure. In particular, the precisely controlled rolling pressurization step drives PDMS to penetrate into the three-dimensional network pores of graphene, enhancing the interfacial bonding and mechanical interlocking strength between the sensing layer and the encapsulation layer. This improves the technical problems of delamination and signal instability caused by weak interfacial bonding, thereby producing a flexible sensor with high durability and high stability.

[0020] Furthermore, during the installation of the first and second base layers, the distance between the roller and the bottom surface of the encapsulation groove is adjusted by the lifting assembly, thereby controlling the thickness of the first and second base layers.

[0021] By controlling the first and second substrate layers to achieve preset thicknesses, not only is the symmetry and consistency of the overall sensor structure guaranteed, but it also helps to optimize its mechanical properties and strain response.

[0022] Furthermore, during the rolling and complete curing steps, when the roller passes over the graphene sensing element, the base temperature control component heats the area corresponding to the graphene sensing element in the encapsulation groove, while the roller temperature control component heats the roller surface to locally reduce the viscosity of the flexible substrate in the area corresponding to the graphene sensing element, promoting the penetration of the flexible substrate into the graphene porous structure. When the roller leaves the area above the graphene sensing element, the base temperature control component cools the area corresponding to the graphene sensing element in the encapsulation groove, while the roller temperature control component cools the roller surface to quickly fix the shape of the flexible substrate.

[0023] This application couples the mechanical process of rolling with dynamic thermal control, dynamically regulating the flowability and curing process of the flexible substrate as rolling progresses. This allows the flexible substrate to fully penetrate the graphene porous structure during rolling, and the morphology of the flexible substrate can be quickly fixed after rolling, preventing excessive flow that could lead to sensor element displacement or pattern blurring. Since temperature control is only performed locally in the area where the graphene sensing element is located, the impact of temperature changes on other areas of the flexible substrate is minimized.

[0024] Furthermore, in the rolling and complete curing steps, the pressure applied by the roller is 0.15±0.02 MPa, the reciprocating rolling speed is 2-10 mm / s, and the number of reciprocating rolling cycles is 2-5.

[0025] This combination of parameters can generate sufficient hydrodynamic force without excessively compressing or damaging the graphene structure, ensuring that PDMS fully fills the three-dimensional pores of graphene, forming a strong mechanical interlock, maximizing the bonding strength at the sensor interface, thereby improving the sensor's fatigue resistance, durability, and signal stability under long-term use.

[0026] In summary, this application includes the following beneficial technical effects: In terms of equipment, the collaborative system consisting of a detachable packaging tank, a rolling mechanism with integrated lifting components, a follow-up feeding tank, and a temperature control system realizes the integrated operation of flexible substrate material coating, thickness control, and rolling, and achieves the spatiotemporal coupling of mechanical rolling and flexible substrate rheological behavior regulation; it not only ensures the uniformity and consistency of PDMS substrate thickness, but also ensures the high stability and repeatability of process parameters through real-time feedback from pressure sensors and precise control by industrial control computers.

[0027] In terms of methodology, this application achieves a breakthrough improvement in the interface bonding between the sensing layer and the encapsulation layer through a process of "layout-pre-curing-rolling penetration-complete curing". Compared with traditional layered encapsulation, this method uses rollers to apply pressure to the semi-cured "PDMS-graphene-PDMS" sandwich structure for reciprocating rolling. Combined with a dynamic thermal control strategy, it can drive the PDMS fluid to fully penetrate and embed into the three-dimensional porous network of graphene, forming a mechanically interlocked structure. Moreover, the PDMS morphology is quickly fixed after rolling. This not only improves the interfacial bonding strength and solves the problem of easy delamination of the sensing layer, but also eliminates the need for additional chemical adhesives.

[0028] The graphene sensor prepared in this application has high sensitivity, excellent flexibility and durability. The integrated structure of the sensing element and the flexible substrate enables it to maintain a stable electrical signal output when subjected to repeated stretching and bending, thus extending its service life. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of a laser-induced graphene-based sensor fabrication device according to an embodiment of this application; Figure 2 This is a flowchart of a laser-induced graphene-based sensor fabrication method according to an embodiment of this application.

[0030] Reference numerals: 1. Base; 2. Placement slot; 3. Encapsulation slot; 4. Guide rail; 5. Mounting bracket; 6. Roller; 7. Feeding slot; 8. Long slot; 9. Column; 10. Collection slot; 11. Baffle; 12. Industrial computer. Detailed Implementation

[0031] The following is in conjunction with the appendix Figure 1-2 This application will be described in further detail.

[0032] This application discloses a laser-induced graphene-based sensor fabrication apparatus. (Refer to...) Figure 1 The laser-induced graphene-based sensor fabrication device includes a base 1, with a placement groove 2 on the upper surface of the base 1. A packaging groove 3 is detachably placed in the placement groove 2. The packaging groove 3 is used to hold and mold a flexible substrate material. In this embodiment, the flexible substrate material is polydimethylsiloxane (PDMS), and the packaging groove 3 is made of polytetrafluoroethylene.

[0033] Reference Figure 1 The laser-induced graphene-based sensor fabrication apparatus also includes a rolling mechanism, which comprises horizontally arranged guide rails 4 and a roller 6 that reciprocates along the guide rails 4. A set of guide rails 4 is arranged on each side of the base 1, and a mounting frame 5 is positioned between the two sets of parallel guide rails 4. The two ends of the mounting frame 5 are slidably mounted on the corresponding guide rails 4, and the roller 6 is rotatably connected to the mounting frame 5. A traveling device is mounted on the mounting frame 5, which drives the mounting frame 5 to translate along the guide rails 4, thereby driving the roller 6 to roll above the encapsulation groove 3. The roller 6 can also be equipped with an independent drive device to drive the roller 6 to rotate at a certain speed, matching the rotational speed of the roller 6 with its translational speed.

[0034] Reference Figure 1 A feeding trough 7 is fixedly installed on the mounting frame 5 for adding flexible substrate prepolymer solution. The feeding trough 7 is located above the roller 6, and an elongated hole 8 is opened on the bottom surface of the feeding trough 7. The axis of the roller 6 is parallel to the elongated hole 8 and the two are located in the same vertical plane. When the mounting frame 5 moves along the guide rail 4, the feeding trough 7 moves synchronously with the roller 6. The flexible substrate prepolymer solution in the feeding trough 7 is continuously and evenly coated onto the surface of the roller 6 through the elongated hole 8, and further coated into the encapsulation tank 3 as the roller 6 rolls.

[0035] A silicone layer is fixedly provided on the outer periphery of the roller 6. The silicone layer has a certain degree of elasticity and flexibility, which can adaptively conform to the surface of the flexible substrate material during rolling. At the same time, the silicone layer has good compatibility with PDMS, which is conducive to the uniform coating of PDMS liquid on the surface of the roller 6.

[0036] The laser-induced graphene-based sensor fabrication apparatus also includes a lifting assembly. (See reference...) Figure 1The base 1 has four fixed columns 9 at its four corners. The lifting assembly includes four linear drive components, each installed in its corresponding column 9. The linear drive components can be hydraulic cylinders, electric push rods, etc. The output end of each linear drive component is fixed to the end of the guide rail 4. Multiple linear drive components extend and retract synchronously, driving the guide rail 4 to rise and fall, thereby driving the roller 6 to rise and fall, adjusting the distance between the roller 6 and the bottom surface of the encapsulation groove 3, i.e., adjusting the thickness of the flexible substrate material coated in the encapsulation groove 3. The linear drive components can integrate pressure sensors to detect the pressure applied by the roller 6 to the flexible substrate material in the encapsulation groove 3.

[0037] To prevent overloading of materials within the encapsulation tank 3, excess flexible substrate material needs to be collected, referring to... Figure 1 Two collection slots 10 are fixedly installed on the base 1, and the two collection slots 10 are located at both ends of the translation path of the roller 6. Furthermore, a baffle 11 is provided between the collection slot 10 and the sealing slot 3. The horizontal plane where the upper end face of the baffle 11 is located is tangent to the arc surface of the roller 6, that is, the upper end face of the baffle 11 and the lowest point of the roller 6 are located on the same horizontal plane.

[0038] The baffle 11 can be driven to rise and fall by an independent drive component, and the rise and fall of the baffle 11 is synchronized with the rise and fall of the mounting frame 5, so that the baffle 11 and the roller 6 rise and fall synchronously, and the upper surface of the baffle 11 can always be flush with the preset liquid level of the flexible base material determined by the height of the roller 6.

[0039] In order to allow excess flexible substrate material in the encapsulation groove 3 to overflow smoothly, the height of the sidewalls of the encapsulation groove 3 at both ends of the translation path of the roller 6 should be low enough, while the height of the other two sidewalls of the encapsulation groove 3 can be set higher.

[0040] The laser-induced graphene-based sensor fabrication device also includes a temperature control system, which comprises a base temperature control component and a roller temperature control component.

[0041] The base temperature control component includes multiple independent micro heating units disposed in the placement slot 2 of the base 1. The positions of some of the micro heating units correspond to the preset placement positions of the graphene sensor elements, and are used to heat or cool the flexible substrate at the location of the graphene sensor elements in the encapsulation slot 3.

[0042] The roller temperature control assembly is used to heat or cool the surface of the roller 6. As one possible implementation, the roller temperature control assembly can employ miniature semiconductor cooling / heating elements, with multiple miniature semiconductor cooling / heating elements arranged in an array between the silicone layer outside the roller 6 and the roller 6. Alternatively, the roller 6 can be configured as a hollow structure and connected to a circulating liquid medium (e.g., water), allowing hot or cold liquid to be introduced into the roller 6 to heat or cool its surface.

[0043] Reference Figure 1 The laser-induced graphene-based sensor fabrication device also includes an industrial computer 12, which is electrically connected to the rolling mechanism, the lifting assembly, and the temperature control system. The industrial computer 12 is used to control the movement speed and direction of the mounting base on the guide rail 4, as well as the height of the mounting frame 5 and the baffle 11, and to control the temperature of the base temperature control assembly and / or the roller temperature control assembly. The industrial computer 12 is also used to receive feedback data from the pressure sensor.

[0044] A method for fabricating a laser-induced graphene-based sensor is implemented using the above-described fabrication apparatus. The fabrication method includes the following steps: Step 1: First layer of substrate installation and pre-curing: The PDMS prepolymer and curing agent were mixed at a mass ratio of 10:1 and stirred at 500 rpm for 5 minutes until homogeneous. Then, the mixture was degassed under vacuum for 15 minutes (vacuum degree ≤ 0.1 MPa) to obtain the PDMS solution.

[0045] The distance between the roller and the bottom surface of the encapsulation tank is adjusted by a lifting assembly to control the thickness of the first substrate layer, while simultaneously adjusting the baffle height. PDMS solution is injected into the feeding tank, and the mounting frame is controlled by an industrial computer to move unidirectionally or reciprocally along the guide rail at a uniform speed of 10 mm / s. The PDMS solution is coated onto the surface of the roller through elongated holes, and the roller lays the first substrate layer into the encapsulation tank during its rolling process. Excess PDMS solution in the encapsulation tank overflows into a collection tank.

[0046] After installation, remove the encapsulation tank from the base and place it in an oven to pre-cure at 60°C for 20 minutes until it reaches a semi-cured state.

[0047] Step 2: Fabrication of graphene sensing elements: Polyimide (PI) films were cut to 50 mm × 50 mm size, immersed in 1 mol / L NaOH solution for 3 minutes, rinsed with deionized water until neutral, and dried to serve as precursor materials. Three-dimensional porous graphene was induced on the PI film surface using a CO2 laser (10 W power, 200 mm / s scanning speed) according to a predetermined pattern. Conductive silver paste was coated at both ends of the graphene and connected with copper wires to obtain a graphene sensing element.

[0048] The graphene sensing element is positioned on the surface of the first pre-cured substrate layer.

[0049] Step 3: Second layer substrate installation and pre-curing: The distance between the roller and the bottom surface of the encapsulation tank is adjusted by a lifting assembly, thereby controlling the thickness of the second substrate layer. PDMS solution is injected into the feeding tank, and the mounting frame is controlled by an industrial computer to move unidirectionally or reciprocally along the guide rail at a uniform speed of 10 mm / s. The PDMS solution is coated onto the surface of the roller through elongated holes. During the rolling process, the roller coats the graphene sensing element with the second substrate layer, forming a PDMS-graphene-PDMS sandwich structure. Excess PDMS solution in the encapsulation tank overflows into a collection tank.

[0050] After installation, remove the encapsulation tank from the base and place it in an oven to pre-cure at 60°C for 20 minutes until it reaches a semi-cured state.

[0051] Step 4, Rolling and Full Curing: The control roller is used to reciprocate and pressurize the pre-cured PDMS-graphene-PDMS sandwich structure with a preset pressure. The pressure applied by the roller is 0.15 MPa, the reciprocating rolling speed is 5 mm / s, and the roller is reciprocated 3 times to allow the flexible substrate material to penetrate into the three-dimensional pores of the graphene sensing element.

[0052] During this process, as the roller passes over the graphene sensing element, the base temperature control component heats the area corresponding to the graphene sensing element within the encapsulation tank (e.g., to 50°C), while the roller temperature control component heats the roller surface to locally reduce the viscosity of PDMS in the area corresponding to the graphene sensing element, promoting the penetration of PDMS into the porous graphene structure. When the roller leaves the graphene sensing element, the base temperature control component cools the area corresponding to the graphene sensing element within the encapsulation tank (e.g., to 20°C), while the roller temperature control component cools the roller surface to quickly fix the PDMS shape and prevent excessive PDMS flow that could cause sensing element displacement or pattern blurring.

[0053] After rolling, the encapsulation tank is removed from the base and placed in an oven to cure at 80°C for 2 hours. After cooling, the PDMS-graphene-PDMS sandwich structure is peeled off from the encapsulation tank to obtain a laser-induced graphene-based sensor.

[0054] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A laser-induced graphene-based sensor preparation device, characterized by: The device comprises: a base; a packaging groove, which is detachably mounted on the base, and is used for containing and forming a flexible substrate material; a rolling mechanism, which comprises a horizontally arranged guide rail and a roller reciprocally moving along the guide rail, the roller is rolling arranged above the packaging groove, and is used for coating the flexible substrate material into the packaging groove and applying pressure to the flexible substrate material in the packaging groove; the rolling mechanism further comprises a lifting assembly, which is used for driving the roller to lift and adjust the distance between the roller and the inner bottom surface of the packaging groove; a feeding groove, which is arranged above the roller and is configured to translate with the roller, and is used for coating the flexible substrate material on the surface of the roller; a temperature control system, which comprises a base temperature control assembly and a roller temperature control assembly, the base temperature control assembly is used for adjusting the temperature of the flexible substrate material in the packaging groove in a partitioned manner, and the roller temperature control assembly is used for adjusting the temperature of the surface of the roller.

2. The apparatus of claim 1, wherein: The bottom surface of the feeding groove is provided with a long hole, and the axis of the roller is parallel to the long hole and located in the same vertical plane.

3. The apparatus of claim 2, wherein: The outer periphery of the roller is fixedly provided with a silica gel layer, and the flexible substrate material is polydimethylsiloxane.

4. The apparatus of claim 1, wherein: Two collecting grooves are fixedly arranged on the base, and the two collecting grooves are respectively located at two ends of the translation path of the roller, and are used for recycling the excess flexible substrate material in the packaging groove.

5. The apparatus of claim 4, wherein: A baffle is arranged between the collecting groove and the packaging groove, the upper end surface of the baffle is tangent to the arc surface of the roller, and the baffle is configured to synchronously lift with the roller.

6. The apparatus of claim 1, wherein: The rolling mechanism further comprises a pressure sensor, which is used for detecting the pressure applied by the roller to the flexible substrate material in the packaging groove.

7. A method of fabricating a laser-induced graphene-based sensor, the method comprising: The device is used for preparing a laser-induced graphene-based sensor, and a preparation method comprises the following steps: ​ first layer substrate paving and pre-solidification: injecting a flexible substrate prepolymer solution into the feeding groove, paving a first layer substrate into the packaging groove by controlling the rolling of the roller, and then pre-solidifying the first layer substrate; graphene sensor element preparation: generating a graphene sensor element on the surface of a carbon precursor film by laser induction, and connecting wires at both ends of the graphene sensor element; positioning the graphene sensor element to the surface of the pre-solidified first layer substrate; second layer substrate paving and pre-solidification: injecting a flexible substrate prepolymer solution into the feeding groove, coating a second layer substrate on the graphene sensor element by controlling the rolling of the roller to form a sandwich structure, and then pre-solidifying the second layer substrate; rolling and complete solidification: controlling the roller to reciprocally roll and press the pre-solidified sandwich structure at a preset pressure, and dynamically adjusting the base temperature control assembly and the roller temperature control assembly to make the flexible substrate material penetrate into the three-dimensional pores of the graphene sensor element; and completely solidifying the sandwich structure after being pressed to obtain a laser-induced graphene-based sensor.

8. The method of claim 7, wherein: When paving the first layer substrate and the second layer substrate, the distance between the roller and the inner bottom surface of the packaging groove is adjusted by the lifting assembly, so as to control the thickness of the first layer substrate and the second layer substrate.

9. The method of claim 7, wherein the method further comprises: In the rolling and complete curing step, when the roller passes above the graphene sensing element, the base temperature control assembly heats the area corresponding to the graphene sensing element in the packaging groove, and at the same time, the roller temperature control assembly heats the surface of the roller to locally reduce the viscosity of the flexible substrate in the corresponding area of the graphene sensing element, promote the penetration of the flexible substrate to the graphene porous structure; when the roller leaves above the graphene sensing element, the base temperature control assembly cools the area corresponding to the graphene sensing element in the packaging groove, and at the same time, the roller temperature control assembly cools the surface of the roller to quickly fix the shape of the flexible substrate.

10. The method of claim 7, wherein the method further comprises: In the rolling and complete curing step, the pressure applied by the roller is 0.15±0.02 MPa, the reciprocating rolling speed is 2-10 mm / s, and the reciprocating rolling times are 2-5 times.

Images