An apparatus and method for continuous roll-to-roll preparation of two-dimensional material thin films

Abstract

This invention provides an apparatus and method for continuous roll-to-roll fabrication of two-dimensional material thin films. In this fabrication apparatus, both the unwinding roller and the winding roller include a first inner cavity portion disposed within a growth chamber and a first outer cavity portion disposed outside the growth chamber. The first inner cavity portion includes a rotating shaft for winding a substrate, and the first outer cavity portion includes a motor for driving the rotating shaft to rotate. The first inner cavity portion and the first outer cavity portion of each unwinding roller and winding roller are magnetically attracted to each other to movably position the unwinding roller and winding roller at both ends of the growth chamber. The magnetic attraction between the first inner cavity portion and the first outer cavity portion enables contactless transmission of the roller system.

Description

Technical Field

[0001] This invention relates generally to the field of nanomaterials and their preparation technology, and in particular to a roll-to-roll continuous preparation apparatus and method for two-dimensional material thin films. Background Technology

[0002] Since its discovery in 2004, graphene has garnered widespread attention for its unique structure and properties. Along with the research boom in graphene, the concept of two-dimensional materials has also emerged. In two-dimensional materials, electrons can move freely only at the nanoscale in two dimensions, resulting in numerous unique properties and superior performance, such as tunable band gaps, photoelectric response, high carrier mobility, high transmittance, and high mechanical strength. With the advancement and deepening of related research, more and more two-dimensional materials are being isolated and applied in various fields such as transparent conductivity, new energy materials, electronic devices, and photoelectric detection. However, for two-dimensional materials to truly achieve industrial application, large-scale fabrication is an essential and crucial step.

[0003] Chemical vapor deposition (CVD) is the most widely used method for preparing two-dimensional (2D) material thin films. Low-pressure CVD (LPCVD) produces 2D material films of superior quality compared to atmospheric pressure CVD (APCVD) and open CVD (OPCVD). To obtain high-quality 2D material films, LPCVD is often used, which requires the CVD growth process to be completed in a vacuum system. Furthermore, since the quality of most 2D material films is extremely sensitive to the vacuum level of the growth chamber, maintaining the vacuum level of the growth chamber during production is a key factor in ensuring the quality of 2D material films.

[0004] Roll-to-roll processing is widely used in the large-scale preparation of materials, offering superior production efficiency and precision compared to other methods. Currently, there are technologies that combine roll-to-roll processing with CVD (Continuous Chemical Vapor Deposition) to achieve continuous preparation of two-dimensional thin films. The integration of roll-to-roll equipment with the CVD chamber mainly falls into two categories: one involves connecting vacuum chambers to both ends of the growth chamber, creating openings in these chambers, and installing the roll-to-roll system inside the vacuum chamber through these openings. The motor connecting the roll system is placed outside the vacuum chamber, and dynamic sealing technology is used to transmit power from outside the vacuum chamber to the internal roll system. The other method involves connecting vacuum chambers to both ends of the growth chamber, installing the roll-to-roll system and the connecting motor together inside the vacuum chamber. The motor is connected to an external power source via an electrode feed flange, ultimately generating power within the vacuum chamber and transmitting it to the roll system. However, both methods present certain challenges in sealing and the impact of thermal radiation on the motor. Furthermore, the need for external vacuum chambers significantly increases the complexity and cost of the equipment.

[0005] Furthermore, in the roll-to-roll production process of two-dimensional material thin films, the substrate may experience problems such as misalignment, wrinkles, and excessive tension due to deformation. There is currently no effective solution for correcting the misalignment and adjusting the tension of the substrate. Summary of the Invention

[0006] In view of the above problems, the present invention proposes an apparatus and method for continuous roll-to-roll preparation of two-dimensional material thin films that overcomes or at least partially solves the above problems.

[0007] One objective of this invention is to provide a roll-to-roll continuous fabrication apparatus and method for two-dimensional material thin films using non-contact magnetic drive, which improves the vacuum level of the cavity, reduces or even avoids the influence of thermal radiation on the motor, and reduces the complexity, installation difficulty, cost, and operation and maintenance difficulty of the fabrication apparatus.

[0008] A further object of the present invention is to achieve real-time, automatic bias correction and tension adjustment of the substrate in a simple manner, while reducing damage to the two-dimensional material film on the substrate.

[0009] According to one aspect of the present invention, a roll-to-roll continuous fabrication apparatus for two-dimensional material thin films is provided, comprising:

[0010] The growth system includes:

[0011] Heating unit;

[0012] The growth chamber includes a growth zone corresponding to the heating unit, as well as an unwinding zone and a winding zone; and

[0013] A vacuum pump is configured to create a vacuum environment within the growth chamber.

[0014] A roll-to-roll drive system includes an unwinding roller disposed in an unwinding zone and a take-up roller disposed in a take-up zone, the unwinding roller and the take-up roller being configured to unwind and take up a substrate for growing a two-dimensional material film thereon, respectively; and

[0015] The control system is configured to control the movement of the unwinding roll and the take-up roll; wherein

[0016] Both the unwinding roll and the take-up roll include a first inner cavity portion disposed within the growth chamber and a first outer cavity portion disposed outside the growth chamber. The first inner cavity portion includes a rotating shaft for winding the substrate, and the first outer cavity portion includes a motor for driving the rotating shaft to rotate. The first inner cavity portion and the first outer cavity portion of each of the unwinding roll and the take-up roll are magnetically attracted to each other to movably place the unwinding roll and the take-up roll at both ends of the growth chamber.

[0017] Optionally, each of the unwinding roll and the winding roll includes a first cavity inner portion and two first cavity outer portions, with the two first cavity outer portions symmetrically placed on both sides of the growth cavity corresponding to the first cavity inner portion to provide a double-sided magnetic attraction effect for the cavity inner portion.

[0018] Optionally, each first cavity further includes: two inner wheels, respectively fixed to both ends of the rotating shaft, with at least a portion of each inner wheel in contact with the inner wall of the growth cavity; and two sets of inner magnets, respectively disposed on the two inner wheels, each set of inner magnets including at least one inner magnet;

[0019] Each first cavity outer portion further includes: an outer wheel, positioned corresponding to the position of the corresponding inner wheel, at least a portion of the outer wheel contacting the outer wall of the growth cavity, and a motor connected to the outer wheel; and a set of outer magnets including at least one outer magnet, arranged on the outer wheel in a manner opposite in position to and with opposite magnetic poles to a set of inner magnets on the corresponding inner wheel.

[0020] Optionally, the shapes of the inner and outer wheels are configured such that the projections of the inner and outer wheels on a plane perpendicular to the axis of rotation match;

[0021] Each set of inner magnets and each set of outer magnets that attract each other includes the same number of inner magnets and outer magnets, and the inner magnets in each set of inner magnets are arranged on the outer edge of the inner wheel in an alternating manner with magnetic poles, and the outer magnets in each set of outer magnets are arranged on the outer edge of the outer wheel in an alternating manner with magnetic poles.

[0022] Optionally, the control system includes:

[0023] The mobile platforms are located on both sides of the growth chamber and are used to place motors on them. The number of mobile platforms is the same as the number of motors.

[0024] A computer configured to receive commands from external input and generate control instructions based on the received commands; and

[0025] The controller is connected to both the mobile platform and the computer via signals. It is configured to receive control commands from the computer and operate the mobile platform according to the control commands.

[0026] Optionally, the control system also includes:

[0027] A displacement sensor, connected to a computer signal, is configured to detect the initial position information of the unwinding roller and the take-up roller shaft and the substrate before the roll-to-roll conveying process and the real-time position information during the roll-to-roll conveying process, and send the initial position information and the real-time position information to the computer.

[0028] The computer is also configured to determine the lateral offset and tension state of the substrate based on the initial position information and the real-time position information, and generate control commands based on the lateral offset and tension state and transmit them to the controller, so that the controller can manipulate the moving platform according to the control commands to drive the unwinding roller and / or the take-up roller to complete the correction and tension adjustment of the substrate.

[0029] Optionally, the number of unwinding rolls and take-up rolls may be one or more;

[0030] The roll-to-roll drive system also includes:

[0031] One or more guide rollers, disposed in the unwinding area and / or the winding area, are used to change the transport direction of the substrate; wherein

[0032] Each guide roller is fixedly installed in the unwinding area and / or the take-up area; or

[0033] Each guide roller includes a second inner cavity portion containing a rotating shaft placed inside the growth cavity and a second outer cavity portion placed outside the growth cavity. The second inner cavity portion and the second outer cavity portion magnetically attract each other to non-fixedly place the guide roller in the unwinding area and / or the winding area.

[0034] According to another aspect of the present invention, a method for continuous roll-to-roll preparation of two-dimensional material thin films is also provided, which is performed using the aforementioned continuous roll-to-roll preparation apparatus for two-dimensional material thin films, the preparation method comprising:

[0035] After the substrate is wound onto the shaft of the unwinding roller and one end of the substrate is connected to the shaft of the take-up roller, the shafts of the unwinding roller and the take-up roller, together with the substrate, are placed horizontally suspended inside the growth chamber by magnetically attracting the inner and outer portions of the first cavity of each of the unwinding roller and the take-up roller.

[0036] Turn on the vacuum pump to create a vacuum environment within the growth chamber;

[0037] Turn on the heating unit and heat the growth chamber to the preset growth temperature;

[0038] The raw materials required for the growth of two-dimensional materials are introduced into the growth chamber;

[0039] The movement of the unwinding and rewinding rollers is controlled to perform roll-to-roll transport of the substrate, thereby growing a two-dimensional material thin film on the substrate.

[0040] Optionally, the roll-to-roll continuous fabrication apparatus for two-dimensional material thin films includes: a moving platform disposed on both sides of the growth chamber for placing motors thereon, the number of moving platforms being the same as the number of motors; and a displacement sensor configured to detect the initial position information of the unwinding roller and the winding roller and the substrate before the roll-to-roll conveying process and the real-time position information during the roll-to-roll conveying process.

[0041] The preparation method also includes:

[0042] Before starting roll-to-roll transfer of the substrate, obtain the initial position information of the unwinding and rewinding rollers and the substrate.

[0043] During the roll-to-roll transfer of the substrate, the real-time position information of the unwinding and rewinding rollers and the substrate is acquired. Based on the initial position information and the real-time position information, the lateral offset and tension state of the substrate are determined. Based on the lateral offset and tension state, the moving platform is controlled to drive the unwinding and rewinding rollers to move, thereby completing the correction of the substrate and the adjustment of the tension force.

[0044] Optionally, the initial position information and real-time position information include the initial position and real-time position of the substrate at the axis of the winding roller in the axial direction of the axis.

[0045] During the roll-to-roll transfer of the substrate, the real-time position information of the unwinding and take-up rollers and the substrate is acquired. Based on the initial position information and the real-time position information, the lateral offset and tension state of the substrate are determined. The moving platform is then controlled to move the unwinding and take-up rollers according to the lateral offset and tension state, thereby completing the steps of substrate correction and tension adjustment. The substrate correction operation includes:

[0046] Obtain the real-time position of the substrate at the axis of the winding roller in the axial direction of the axis;

[0047] The difference between the initial position and the real-time position of the substrate at the axis of the winding roller in the axial direction is calculated as the lateral offset Δx of the substrate.

[0048] When |Δx| is greater than or equal to the preset lateral offset threshold, the side of the growth cavity to which the substrate is biased is determined according to the lateral offset Δx. The moving platform corresponding to the take-up roller and set on the other side of the growth cavity is controlled to drive the motor on the moving platform to move in the opposite direction along the substrate conveying direction by a set distance Δd1. Thus, through the magnetic attraction between the first cavity outer part and the first cavity inner part of the take-up roller, the rotating shaft of the take-up roller is driven to deviate from its axial direction by an angle Δθ, where Δd1<|Δx|, tan(Δθ)=Δd1 / l, and l is the dimension of the growth cavity in the axial direction of the rotating shaft.

[0049] Repeatedly acquire the real-time position of the substrate at the shaft of the take-up roller in the axial direction of the shaft, calculate the lateral offset Δx of the substrate, and control the moving platform corresponding to the take-up roller, which is located on the other side of the growth chamber, to drive the motor on the moving platform to move in the opposite direction of the substrate conveying direction by a set distance Δd1 until |Δx| is less than the preset lateral offset threshold, and then control the moving platform to drive the motor of the take-up roller back to its initial position.

[0050] Optionally, the initial position information and real-time position information also include the initial and real-time positions of the shafts of the unwinding roller and the take-up roller in the substrate conveying direction, and the initial and real-time positions of the substrate in the vertical direction at a predetermined distance from the center line of the shaft of the unwinding roller or the take-up roller.

[0051] During the roll-to-roll transfer of the substrate, the real-time position information of the unwinding and take-up rollers and the substrate is acquired. Based on the initial position information and the real-time position information, the lateral offset and tension state of the substrate are determined. The moving platform is then controlled to move the unwinding and take-up rollers according to the lateral offset and tension state, thereby completing the steps of substrate correction and tension adjustment. The operation of adjusting the substrate tension includes:

[0052] The real-time position of the unwinding roller and the winding roller in the substrate conveying direction, and the real-time position of the substrate in the vertical direction at a predetermined distance from the center line of the unwinding roller or the winding roller.

[0053] The difference between the initial position and the real-time position of the substrate in the vertical direction at a predetermined distance from the center line of the unwinding or winding roller is calculated as the vertical change distance Δz of the substrate.

[0054] When the vertical change distance Δz is greater than or equal to the preset vertical change distance threshold, the control of the moving platforms on both sides corresponding to one of the unwinding roller and the winding roller simultaneously drives the motor of that roller to move horizontally a set distance Δd2 away from the other roller, where Δd2 < Δz.

[0055] Repeatedly acquire the real-time position of the substrate in the vertical direction at a predetermined distance from the center line of the rotation axis of the unwinding roller or the take-up roller, calculate the vertical change distance Δz, and control the moving platforms on both sides corresponding to one of the unwinding roller and the take-up roller to simultaneously drive the motor of that one to move horizontally a set distance Δd2 away from the other until the vertical change distance Δz is less than the preset vertical change distance threshold.

[0056] The difference between the initial and real-time positions of the unwinding and winding rollers in the substrate conveying direction is calculated as the longitudinal offset Δy of the rollers.

[0057] When the longitudinal offset Δy of either the unwinding roll or the take-up roll is greater than the preset longitudinal offset threshold, the moving platforms on both sides corresponding to one of the unwinding roll and the take-up roll are controlled to simultaneously drive the motor of that one to move horizontally a set distance Δd3 in the direction closer to the other, where Δd3 < Δy.

[0058] Repeatedly acquire the real-time position of the unwinding roller and the take-up roller shaft in the substrate conveying direction, calculate the longitudinal offset Δy of the shaft, and control the moving platforms on both sides corresponding to one of the unwinding roller and the take-up roller to simultaneously drive the motor of that one to move horizontally a set distance Δd3 in the direction closer to the other until the longitudinal offset Δy of the shaft of both the unwinding roller and the take-up roller is less than the preset longitudinal offset threshold.

[0059] In the roll-to-roll continuous fabrication apparatus and method for two-dimensional material thin films provided by this invention, both the unwinding roller and the take-up roller include a first cavity portion containing a rotating shaft placed inside the growth chamber and a first outer cavity portion containing a motor placed outside the growth chamber. The first cavity portion and the first outer cavity portion magnetically attract each other to movably position the unwinding roller and the take-up roller at both ends of the growth chamber. The magnetic attraction between the first cavity portion and the first outer cavity portion enables contactless transmission of the roller system. Therefore, the growth chamber does not need to be connected to an additional vacuum chamber to open holes for installing the roll-to-roll roller system, thus improving the vacuum level of the growth chamber. At the same time, since the motor is placed outside the growth chamber, the influence of heat radiation on the motor is greatly reduced or even avoided. Moreover, since the roller system does not need to be fixedly installed, the rotating shaft of the roller system can be freely removed during sample loading and unloading, making the operation and maintenance of the device very convenient. Thus, the complexity, installation difficulty, cost, and operation and maintenance difficulty of the fabrication apparatus are reduced.

[0060] Furthermore, in the roll-to-roll continuous fabrication apparatus and method for two-dimensional material thin films provided by this invention, displacement sensors detect the initial position information of the unwinding and rewinding rollers and the substrate before the roll-to-roll conveying process, as well as the real-time position information during the roll-to-roll conveying process. Based on this initial and real-time position information, the moving platform is controlled, and the moving platform drives the unwinding and / or rewinding rollers to move to complete the substrate correction and tension adjustment. Thus, only two drive rollers are needed to achieve multiple functions such as rewinding, unwinding, automatic correction, tension adjustment, and stress distribution control of the substrate, improving the reliability and practicality of the equipment and further reducing the complexity and cost of the apparatus. Moreover, since this correction and tension adjustment method does not require the establishment of friction between the substrate and the roller surface, it causes almost no damage to the two-dimensional material thin film on the substrate.

[0061] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below.

[0062] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0063] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0064] Figure 1 This is a schematic diagram of a roll-to-roll continuous fabrication apparatus for two-dimensional material thin films according to an embodiment of the present invention;

[0065] Figure 2 This is a schematic diagram of a roll-to-roll continuous fabrication apparatus for two-dimensional material thin films according to another embodiment of the present invention;

[0066] Figure 3a This is a schematic diagram of the structure of an unwinding roller according to an embodiment of the present invention;

[0067] Figure 3b This is a schematic diagram of the structure of an unwinding roller according to another embodiment of the present invention;

[0068] Figure 4a This is a schematic diagram showing the arrangement of inner magnets on the inner wheel of an unwinding roller or a take-up roller according to an embodiment of the present invention.

[0069] Figure 4b This is a schematic diagram showing the arrangement of outer magnets on the outer wheel of an unwinding roller or a take-up roller according to an embodiment of the present invention;

[0070] Figure 5 This is a schematic diagram of the structure of a guide roller according to an embodiment of the present invention;

[0071] Figure 6 This is a schematic diagram of the structure of a mobile platform according to an embodiment of the present invention;

[0072] Figure 7 This is a schematic diagram of substrate correction according to an embodiment of the present invention;

[0073] Figure 8 This is a schematic diagram illustrating the adjustment of substrate tension according to an embodiment of the present invention;

[0074] Figure 9a and Figure 9b These are schematic top views and schematic front views of a traditional alignment roller in operation, respectively.

[0075] Figure 10a This is a schematic force analysis diagram of a traditional tension adjustment roller in the prior art;

[0076] Figure 10b This is a schematic diagram of the operation of a traditional tension adjusting roller in the prior art;

[0077] Figure 11 This is a schematic diagram of a conventional magnetic coupling used in a roll-to-roll continuous fabrication device.

[0078] Figure 12 This is a schematic flowchart of a roll-to-roll continuous fabrication method for two-dimensional material thin films according to an embodiment of the present invention;

[0079] Figure 13 Photographs of two-dimensional material films prepared according to embodiments of the present invention, wherein (a) is a graphene film with a characteristic length of meters prepared in Example 1, and (b) is a graphene-carbon nanotube composite film with a characteristic length of meters prepared in Example 2;

[0080] Figure 14 The image shows a scanning electron microscope image of a graphene film with a characteristic length in the meter range prepared in Example 1.

[0081] Figure 15 The image shows a scanning electron microscope image of the graphene-carbon nanotube composite film with a characteristic length of meters prepared in Example 2.

[0082] Figure 16 Raman spectra of the graphene film with a characteristic length of meters prepared in Example 1, the carbon nanotube film with a characteristic length of meters used in Example 2, and the prepared graphene-carbon nanotube composite film with a characteristic length of meters. Detailed Implementation

[0083] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0084] Currently, with the advancement and deepening of research, more and more two-dimensional materials are being isolated, such as boron nitride, black phosphorus, two-dimensional transition metal disulfides (molybdenum disulfide, tungsten disulfide), two-dimensional transition metal carbides (titanium carbide, vanadium carbide, etc.), and two-dimensional transition metal nitrides (titanium nitride, vanadium nitride, etc.), and are being applied in many fields such as transparent conductivity, new energy materials, electronic devices, and photoelectric detection. In order to achieve the large-scale preparation of two-dimensional materials, some methods have emerged that combine roll-to-roll process with CVD method. There are two main types: (1) Vacuum chambers are connected to both ends of the growth chamber and the external vacuum chambers are opened. The roll system required for roll-to-roll is installed inside the vacuum chamber from the opening. The motor connecting the roll system is placed outside the vacuum chamber. Then, through dynamic sealing technology, the power is finally transmitted from the outside of the vacuum chamber to the internal roll system; (2) Vacuum chambers are connected to both ends of the growth chamber. The roll system required for roll-to-roll and the motor connecting the roll system are installed together inside the vacuum chamber. The motor is connected to the external power supply through the electrode feed flange. Finally, the power is generated inside the vacuum chamber and transmitted to the roll system.

[0085] However, although both methods can achieve power transmission in a vacuum cavity, they are still accompanied by certain problems.

[0086] (1) For the first method, since the existing dynamic sealing technology has not yet achieved zero leakage, the method of installation with openings will have a significant impact on the vacuum level of the cavity. In particular, when the roller system is in operation for a long time, the possibility of leakage from the dynamic seal will also increase greatly, which will seriously affect the reliability of the equipment. Furthermore, dynamic sealing technology is complex, costly, and difficult to maintain, which to some extent limits the application of this method.

[0087] (2) For the second method, since the growth temperature of two-dimensional material films often needs to reach thousands of degrees Celsius, the growth chamber will generate considerable heat radiation to the external vacuum chamber. Therefore, the roller system and motor placed inside the vacuum chamber need to operate in an environment higher than room temperature for a long time. Furthermore, due to the vacuum environment, the motor cannot dissipate heat directly, which not only affects the service life of the motor but also exacerbates the outgassing of motor components. This will have a significant impact on the vacuum environment of the chamber. In addition, since both the roller system and the motor need to be built-in, the required vacuum chamber size will also increase exponentially, greatly increasing the difficulty of sealing and maintaining the vacuum chamber.

[0088] In addition, both methods require external vacuum chambers at both ends of the growth chamber to enable the installation, use and maintenance of the system, which greatly increases the complexity and cost of the equipment.

[0089] In the roll-to-roll production of two-dimensional thin films, the ideal situation is that the rollers are perfectly parallel, the substrate and each roller have good contact, and the substrate has no deformation, thus achieving perfect unwinding and rewinding. However, in reality, there will always be some error in the parallel arrangement of the rollers, and the substrate after high-temperature growth will inevitably undergo geometric deformation. This will lead to the following problems during unwinding and rewinding: (1) the substrate in the suspended part may sag and bend due to insufficient tension, resulting in wrinkles and easy deviation during rewinding; (2) the substrate in the suspended part may break due to excessive tension, resulting in rewinding failure; (3) the substrate may deviate during rewinding, resulting in wrinkles or even rewinding failure. The solution to this problem is to perform real-time correction and tension adjustment of the substrate during roll-to-roll production to prevent substrate deviation, ensure normal unwinding and rewinding, and obtain a flat and wrinkle-free two-dimensional material / substrate. Especially in mass production, the substrate length can reach thousands of meters, making real-time correction and tension adjustment of the substrate during production indispensable.

[0090] Unfortunately, existing technologies for roll-to-roll production equipment and methods for two-dimensional material films rarely address the issues of web alignment and tension adjustment; only a very few devices incorporate traditional web alignment rollers and tension adjustment rollers into their roller systems. The working principles of traditional web alignment rollers and tension adjustment rollers are as follows: Figures 9a to 10b As shown. Figure 9a This is a schematic top view of the alignment roller in operation. When the substrate shifts, the alignment roller corrects the substrate by moving laterally. Figure 9b This is a schematic front view of the alignment roller in operation. The alignment roller is often equipped with a guide roller to establish sufficient friction between the substrate and the alignment roller. Figure 10a This is a schematic force analysis diagram of the tension adjustment roller, where the frictional force (f) between the substrate and the roller surface is converted into the required tension (T2-T1). Figure 10b This is a schematic diagram of a set of tension adjustment rollers. For roll-to-roll growth of two-dimensional (2D) thin films, the bonding between the substrate and the 2D film often relies on weak interactions. Therefore, the substrate on which the 2D film is grown is not wear-resistant. Traditional alignment rollers and tension adjustment rollers rely on establishing friction on the substrate to achieve alignment and tension adjustment, which inevitably leads to damage or even detachment of the 2D film. Therefore, developing a novel alignment and tension adjustment method is of paramount importance for the roll-to-roll growth of 2D thin films.

[0091] To address the above-mentioned problems, this invention provides a roll-to-roll continuous fabrication apparatus 10 for two-dimensional material thin films.

[0092] Figure 1This is a schematic diagram of the structure of a roll-to-roll continuous fabrication apparatus 10 for two-dimensional material thin films according to an embodiment of the present invention, wherein the x-direction is the axial direction of the shaft 211 of the unwinding roller or the take-up roller, the y-direction is the substrate conveying direction, and the z-direction is the vertical direction. Figure 2 This is a schematic diagram of the structure of a roll-to-roll continuous fabrication apparatus 10 for two-dimensional material thin films according to another embodiment of the present invention. The following is in conjunction with... Figure 1 and Figure 2 The two-dimensional material thin film roll-to-roll continuous preparation apparatus 10 of the present invention will be described.

[0093] See Figure 1 and Figure 2 As shown, in one embodiment, the roll-to-roll continuous fabrication apparatus 10 for two-dimensional material thin films of the present invention generally includes a growth system, a roll-to-roll drive system, and a control system.

[0094] The growth system includes: a heating unit 11; a growth chamber 12, which includes a growth region 122 corresponding to the heating unit 11, an unwinding region 121 and a winding region 123; and a vacuum pump 52 configured to create a vacuum environment inside the growth chamber 12.

[0095] The roll-to-roll drive system includes an unwinding roller 21 disposed in the unwinding zone 121 and a take-up roller 22 disposed in the take-up zone 123. The unwinding roller 21 and the take-up roller 22 are configured to unwind and take up the substrate 23 on which a two-dimensional material film is grown, respectively.

[0096] The control system is configured to control the movement of the unwinding roller 21 and the winding roller 22.

[0097] Specifically, both the unwind roller 21 and the take-up roller 22 include a first inner cavity portion located within the growth chamber 12 and a first outer cavity portion located outside the growth chamber 12. The first inner cavity portion includes a rotating shaft 211 for winding the substrate 23, and the first outer cavity portion includes a motor 216 for driving the rotating shaft 211 to rotate. The first inner cavity portion and the first outer cavity portion of each of the unwind roller 21 and the take-up roller 22 are magnetically attracted to each other to movably position the unwind roller 21 and the take-up roller 22 at both ends of the growth chamber 12.

[0098] The roll-to-roll continuous fabrication apparatus 10 for two-dimensional thin films of this invention combines a continuous roll-to-roll drive with a two-dimensional thin film CVD growth method. Both the unwinding roller 21 and the take-up roller 22 include a first cavity portion containing a rotating shaft 211 located within the growth chamber 12 and a first outer cavity portion containing a motor 216 located outside the growth chamber 12. The first cavity portion and the first outer cavity portion magnetically attract each other to movably position the unwinding roller 21 and the take-up roller 22 at both ends of the growth chamber 12. The magnetic attraction between the first cavity portion and the first outer cavity portion enables contactless transmission of the roller system. Therefore, the growth chamber does not need to be connected to an additional vacuum chamber to open holes for installing the roll-to-roll roller system, thus improving the vacuum level of the growth chamber. Simultaneously, since the motor 216 is placed outside the growth chamber, the impact of heat radiation on the motor is greatly reduced or even avoided. Moreover, since the roller system does not require fixed installation, the rotating shaft of the roller system can be freely removed during sample loading and unloading, making the operation and maintenance of the apparatus very convenient. This reduces the complexity of the preparation device, the difficulty of installation, the cost, and the difficulty of operation and maintenance.

[0099] The growth system is used to grow two-dimensional material films, and the growth chamber 12 is statically sealed to avoid additional leakage.

[0100] Two-dimensional material thin films may include, but are not limited to, graphene, carbon nanotubes, boron nitride, black phosphorus, two-dimensional transition metal disulfides (molybdenum disulfide, tungsten disulfide, etc.), two-dimensional transition metal carbides (titanium carbide, vanadium carbide, etc.), two-dimensional transition metal nitrides (titanium nitride, vanadium nitride, etc.), and two-dimensional material composite thin films such as graphene-carbon nanotubes, graphene-boron nitride, etc.

[0101] The heating unit 11 can be configured as a single-temperature zone, dual-temperature zone, or even multi-temperature zone heating mode according to the growth requirements of two-dimensional materials. The main body of the growth chamber 12 is placed inside the heating unit 11, with both ends extending out of the heating unit 11.

[0102] In some embodiments, the growth system may further include an air inlet 13 and an air outlet 14, with the two ends of the growth chamber 12 connected to the air inlet 13 and the air outlet 14, respectively.

[0103] Generally, the air inlet 13 and the air outlet 14 are located at both ends of the growth chamber 12, depending on the growth process. Since the roll-to-roll drive system of the present invention has configuration flexibility and can drive in the opposite direction, the specific positions of the air inlet 13 and the air outlet 14 can be flexibly set according to the transmission direction of the roll-to-roll drive system.

[0104] The growth chamber 12 can be made of non-magnetic materials. Preferably, it is made of high-temperature resistant non-magnetic materials, including but not limited to quartz, corundum, graphite, stainless steel, high-temperature resistant ceramics, etc.

[0105] The shape of the growth chamber 12 is not limited, and it can even be asymmetrical in the unwinding and rewinding areas. Preferably, the growth chamber 12 has a regular shape, for example, it is a round tube or a square tube.

[0106] As previously described, the growth chamber 12 includes an unwinding area 121, a growth area 122, and a winding area 123. The growth area 122 may be located in the isothermal zone within the heating unit 11 and is used to grow two-dimensional material films. The isothermal zone may be configured as a single-temperature zone, a dual-temperature zone, or even a multi-temperature zone. The unwinding area 121 and the winding area 123 are located outside the heating unit 11 and are used to house components of the roll-to-roll drive system. The dimensions of the growth chamber 12 and each region within the growth chamber 12 depend on the actual needs of two-dimensional material film growth and are not specifically limited.

[0107] As mentioned earlier, since the unwinding roller 21 and the take-up roller 22 are structurally separate, with one part of the roller system located inside the growth chamber 12 and the other part located outside the growth chamber 12, and there is no rigid connection between the internal and external structures, the external structure (i.e., the part outside the first chamber) transmits power to the internal structure (i.e., the part inside the first chamber) by magnetic force. Therefore, the growth chamber 12 can be installed and operated without any modifications such as drilling holes or installing bearings. Furthermore, since the installation and operation of the roller system do not require any rigid connections or fixed bearings, the positions of the unwinding roller 21 and the take-up roller 22 can move freely, which greatly improves the flexibility of the device.

[0108] In some embodiments, each of the unwinding roller 21 and the take-up roller 22 includes a first inner cavity portion and two first outer cavity portions. The two first outer cavity portions are symmetrically placed on both sides of the growth cavity 12, corresponding to the first inner cavity portions, to provide a double-sided magnetic attraction for the inner cavity portions. In other words, the unwinding roller 21 is separately placed in the unwinding area 121 of the growth cavity by means of double-sided inner and outer magnetic attraction, and the take-up roller 22 is also separately placed in the take-up area 123 of the growth cavity by means of double-sided inner and outer magnetic attraction. Thus, the internal structures of the unwinding roller 21 and the take-up roller 22 achieve force balance at their respective positions by means of double-sided magnetic attraction on both sides of the growth cavity 12, thereby making the roll-to-roll drive system structure more stable.

[0109] The number of unwinding rollers 21 and take-up rollers 22 can each be ≥1, and their respective numbers and combinations can be configured as needed. Optionally, unwinding rollers 21 and take-up rollers 22 are matched and their numbers are equal and ≥1. Optionally, each unwinding roller 21 (total number of unwinding rollers 21 ≥1) is equipped with multiple take-up rollers 22 (total number of take-up rollers 22 ≥2), or conversely, each take-up roller 22 is equipped with multiple unwinding rollers 21. Optionally, multiple unwinding rollers 21 (total number of unwinding rollers 21 ≥2) are equipped with multiple take-up rollers 22 (total number of take-up rollers 22 ≥2). The substrate 23 is wound around the unwinding rollers 21 and take-up rollers 22 at both ends, and is suspended inside the growth chamber 12 by tension at both ends. The number of substrates 23 is configured according to the growth requirements of the two-dimensional material thin film and is not specifically limited.

[0110] The positions and arrangement of the unwinding roller 21 and the take-up roller 22 are designed according to the needs of the growth chamber 12 and the size and shape of the film growth. Preferably, the positions and arrangement of the unwinding roller 21 and the take-up roller 22 need to adapt to the geometry of the growth chamber 12.

[0111] The unwinding roller 21 is used to wind the substrate 23 and, during the growth of two-dimensional material thin films, non-contactly transmits power from the outside of the growth chamber 12 to the inside of the growth chamber 12 for unwinding and transporting the substrate 23. Figure 3a This is a schematic diagram of the structure of the unwinding roller 21 according to an embodiment of the present invention; Figure 3b This is a schematic diagram of the structure of the unwinding roller 21 according to another embodiment of the present invention. Figure 3a and 3b As shown, the first cavity of the unwinding roller 21 further includes two inner wheels 213, which are fixed to both ends of the rotating shaft 211 respectively, and at least a portion of each inner wheel 213 is in contact with the inner wall of the growth cavity 12; and two sets of inner magnets 212, which are respectively disposed on the two inner wheels 213, and each set of inner magnets 212 includes at least one inner magnet 212. The outer cavity of each first cavity of the unwinding roller 21 further includes: an outer wheel 215, which is placed corresponding to the position of the corresponding inner wheel 213, and at least a portion of the outer wheel 215 is in contact with the outer wall of the growth cavity 12; a motor 216 is connected to the outer wheel 215 (specifically, the output shaft of the motor 216 can be connected to the outer wheel 215, so that the motor 216 drives the outer wheel 215 to rotate); and a set of outer magnets 214, including at least one outer magnet 214, which are disposed on the outer wheel 215 in a manner that is opposite in position to and has opposite magnetic poles to the set of inner magnets 212 on the corresponding inner wheel 213. Thus, each inner wheel 213 of the unwinding roller 21 and its corresponding outer wheel 215 are magnetically attracted by the inner magnet 212 and the outer magnet 214, thereby allowing the rotating shaft 211 to be suspended inside the unwinding area 121.

[0112] To achieve a good magnetic attraction connection (also known as magnetic coupling) between the outer wheel 215 and the inner wheel 213, in some embodiments, the shapes of the opposing inner wheel 213 and outer wheel 215 are configured such that their projections on a plane perpendicular to the axis of rotation match. Preferably, the projections of the inner wheel 213 and outer wheel 215 on a plane perpendicular to the axis of rotation coincide. Optionally, the projections of the inner wheel 213 and outer wheel 215 on a plane perpendicular to the axis of rotation are both polygonal disk-shaped. Preferably, the projections of the inner wheel 213 and outer wheel 215 on a plane perpendicular to the axis of rotation are both disk-shaped.

[0113] In some embodiments, each group of inner magnets 212 and each group of outer magnets 214 that attract each other include the same number of inner magnets 212 and outer magnets 214, and the multiple inner magnets 212 in each group of inner magnets 212 are arranged on the outer edge of the inner wheel 213 in an alternating manner, and the multiple outer magnets 214 in each group of outer magnets 214 are arranged on the outer edge of the outer wheel 215 in an alternating manner.

[0114] Figure 4a This is a schematic diagram showing the arrangement of inner magnets 212 on the inner wheel 213 of the unwinding roller 21 or the take-up roller 22 according to an embodiment of the present invention. Figure 4b This is a schematic diagram showing the arrangement of outer magnets 214 on the outer wheel 215 of the unwinding roller 21 or the take-up roller 22 according to an embodiment of the present invention. See also Figure 4a and 4b As shown, in some specific embodiments, the inner magnet 212 is arranged with alternating N-S magnetic poles on the outer edge of the inner wheel 213, and the outer magnet 214 is arranged with alternating S-N magnetic poles on the outer edge of the outer wheel 215, thereby forming a magnetic attraction connection (also known as magnetic coupling) between the inner wheel 213 and the outer wheel 215.

[0115] In some embodiments, the materials of the shaft 211 and the inner wheel 213 are capable of withstanding temperatures above a certain level and are low-cost and easy to process. Preferably, the materials of the shaft 211 and the inner wheel 213 are capable of withstanding 100°C. Optionally, the materials of the shaft 211 and the inner wheel 213 may be quartz, corundum, graphite, ceramic, stainless steel, polytetrafluoroethylene, etc.

[0116] In some embodiments, the inner ring 213 may be selected from any of the following shapes: spherical crown, spherical shell crown, conical, pyramidal, umbrella-shaped, arched, disc-shaped with a central protrusion, disc-shaped with a central tip, disc-shaped with a central ball bearing, etc. For example, for the cylindrical growth cavity 12, a spherical crown-shaped inner ring 213 may be selected (e.g., Figure 3a As shown), other shapes of inner wheels can also be used; for the square tubular growth cavity 12, a disc-shaped inner wheel 213 with a ball bearing in the center can be selected (such as...). Figure 3b(As shown), other inner wheel shapes can also be used. A disc shape with a central ball bearing is preferred. Through the special design of the inner wheel 213's shape, the surface of the inner wheel 213 facing the inner wall of the growth chamber 12 has a minimal contact area with the inner wall of the growth chamber 12, thereby minimizing the friction between the inner wheel 213 and the inner wall of the growth chamber 12. This allows the inner wheel 213 to rotate and move freely within the growth chamber 12 with minimal resistance during roll-to-roll transport without any rigid linkage, while simultaneously ensuring sufficient magnetic attraction (magnetic coupling) between the inner wheel 213 and the outer wheel 215.

[0117] In some embodiments, the inner wheel 213 may also undergo surface treatment to make the portion of the inner wheel 213 in contact with the inner wall of the growth chamber 12 smooth, thereby further reducing the frictional force at the contact portion between the inner wheel 213 and the inner wall of the growth chamber 12. The surface treatment method for the inner wheel 213 may be selected according to the material, including high-temperature melting, mechanical polishing, electrochemical polishing, anodizing, electrophoresis, micro-arc oxidation, powder coating, surface wire drawing, sandblasting, electroplating, etc., with mechanical polishing being preferred.

[0118] The outer wheel 215 can be made of lightweight, low-cost, and easy-to-process materials. Optional materials for the outer wheel 215 include polyethylene, polypropylene, polyvinyl chloride, polystyrene, ABS, rubber, graphite, and hollow stainless steel.

[0119] In some embodiments, the inner magnet 212 is made of a magnetic material. Due to the thermal radiation of the growth region 122, the ambient temperature of the unwinding region 121 and the winding region 123 is typically higher than room temperature. Therefore, in some embodiments, the Curie temperature of the magnetic material is higher than the ambient temperature of the unwinding region 121 and the winding region 123, thereby ensuring the stability and durability of the inner magnet 212.

[0120] Optionally, the magnetic material of the inner magnet 212 is a permanent magnet, such as ferrite, iron-manganese oxide, AlNiCo alloy, Samarium-cobalt alloy, iron-titanium alloy, copper-nickel-iron alloy, iron-cobalt-molybdenum alloy, iron-cobalt-vanadium alloy, manganese-bismuth alloy, etc., or a ferromagnet, such as iron, cobalt, nickel, etc. Preferably, the magnetic material of the inner magnet 212 is a neodymium-iron-boron alloy.

[0121] In some embodiments, the external magnet 214 is made of a magnetic material. Optionally, the magnetic material of the external magnet 214 is a permanent magnet, such as ferrite, iron-manganese oxide, AlNiCo alloy, Samarium-cobalt alloy, iron-titanium alloy, copper-nickel-iron alloy, iron-cobalt-molybdenum alloy, iron-cobalt-vanadium alloy, manganese-bismuth alloy, etc., or an electromagnet. Preferably, the magnetic material of the external magnet 214 is a neodymium-iron-boron alloy.

[0122] The inner magnet 212 and the outer magnet 214 can be made of the same material or different materials.

[0123] The take-up roller 22 is used to connect to the substrate 23 and, during the growth of the two-dimensional material thin film, to non-contactly transmit power from the outside of the growth chamber 12 to the inside of the growth chamber 12 to wind up the two-dimensional material thin film / substrate 23. The structure of the take-up roller 22 is the same as that of the unwind roller 21, and will not be described again here.

[0124] In some embodiments, the roll-to-roll drive system may further include one or more guide rollers 24 disposed in the unwinding area 121 and / or the take-up area 123 to change the transport direction of the substrate 23, thereby adapting the geometric arrangement of the substrate 23 to the shape of the cavity. The guide rollers 24 are positioned appropriately in the unwinding area 121 and the take-up area 123 according to the space of the growth cavity 12 and the arrangement requirements of the unwinding rollers 21 and the take-up rollers 22. For example, when the position and arrangement of the unwinding rollers 21 and the take-up rollers 22 need to adapt to the geometry of the growth cavity 12, or when multiple sets of unwinding rollers 21 and take-up rollers 22 need to be arranged within a certain space of the growth cavity 12, guide rollers 24 (such as...) are installed in the growth cavity 12. Figure 2 (As shown).

[0125] In some alternative embodiments, each guide roller 24 is fixedly mounted at any desired position in the unwinding area 121 and / or the winding area 123 of the growth chamber 12. In this case, conventional fixing mechanisms can be used to fix the guide rollers 24 in place.

[0126] In some alternative embodiments, each guide roller 24 is non-fixedly placed at any desired position in the unwinding area 121 and / or winding area 123 of the growth chamber 12 by means of internal and external magnetic attraction (magnetic coupling).

[0127] Figure 5 This is a schematic diagram of the structure of a guide roller 24 according to an embodiment of the present invention. See also: [illustration details in the original text]. Figure 5 As shown, each guide roller 24 includes a second cavity inner portion, including a rotating shaft 241, located within the growth cavity 12, and a second cavity outer portion located outside the growth cavity 12. The second cavity inner portion and the second cavity outer portion magnetically attract each other to non-fixedly place the guide roller 24 in the unwinding area 121 and / or the winding area 123. In other words, each guide roller 24 includes an internal structure (i.e., the second cavity inner portion) and an external structure (i.e., the second cavity outer portion), which are not rigidly connected, and the internal structure achieves force balance by magnetic force.

[0128] Further, see also Figure 5 Each guide roller 24 includes a second inner cavity portion and two second outer cavity portions. The two second outer cavity portions are symmetrically placed on both sides of the growth cavity 12, corresponding to the first inner cavity portion, to provide a double-sided magnetic attraction effect for the second inner cavity portion. In other words, the external structure of the guide roller 24 is symmetrically placed on both sides of the growth cavity to provide a double-sided magnetic coupling force for the internal structure.

[0129] In some specific embodiments, see also [link to specific implementation]. Figure 5 The second cavity of the guide roller 24 further includes two inner wheels 243, which are fixed to both ends of the rotating shaft 241, and at least a portion of each inner wheel 243 contacts the inner wall of the growth cavity 12; and two sets of inner magnets 242, which are respectively disposed on the two inner wheels 243, each set of inner magnets 242 including at least one inner magnet 242. The outer portion of each second cavity of the guide roller 24 further includes: an outer wheel 245, which is placed corresponding to the position of the corresponding inner wheel 243, and at least a portion of the outer wheel 245 contacts the outer wall of the growth cavity 12; and a set of outer magnets 244, including at least one outer magnet 244, which are disposed on the outer wheel 245 in a manner opposite in position and magnetic pole to the set of inner magnets 242 on the corresponding inner wheel 243. Thus, each inner wheel 243 of the guide roller 24 and its corresponding outer wheel 245 form a magnetic attraction (magnetic coupling) through the inner magnet 242 and the outer magnet 244, thereby allowing the rotating shaft 241 to be suspended inside the unwinding area 121 and / or the winding area 123.

[0130] In some embodiments, the shapes of the opposing inner wheel 243 and outer wheel 245 are configured such that the projections of the inner wheel 243 and outer wheel 245 on a plane perpendicular to the axis of rotation match.

[0131] In some embodiments, each group of inner magnets 242 and each group of outer magnets 244 that attract each other include the same number of inner magnets 242 and outer magnets 244, and the multiple inner magnets 242 in each group of inner magnets 242 are arranged on the outer edge of the inner wheel 243 in an alternating manner with magnetic poles, and the multiple outer magnets 244 in each group of outer magnets 244 are arranged on the outer edge of the outer wheel 245 in an alternating manner with magnetic poles.

[0132] The inner wheel 243, outer wheel 245, inner magnet 242 and outer magnet 244 of the guide roller 24 can be made of the same material and arrangement as the unwinding roller 21 and the take-up roller 22, and will not be described again here.

[0133] In embodiments of the present invention, the outer wheel 245 of the guide roller 24 and the inner wheel 243 form a magnetic attraction (magnetic coupling). The outer wheel 245 overcomes its own gravity by relying on the frictional force between itself and the outer wall of the growth chamber 12 generated by the magnetic coupling, allowing the guide roller 24 to be placed at any position on the growth chamber 12 and to be moved at any time according to actual needs. Compared with the traditional fixed installation, the non-fixed placement of the guide roller 24 has greater flexibility.

[0134] In some embodiments, see Figure 1 and Figure 2As shown, the growth system of the roll-to-roll continuous fabrication apparatus 10 for two-dimensional material thin films may further include a gas source 4. The gas source 4 is connected to an inlet 13 and is configured to input the material gases required for the growth of the two-dimensional material thin film into the growth chamber 12 through the inlet 13. The composition of the gas source 4 depends on the requirements for the growth of the two-dimensional material thin film and is not specifically limited herein. It may include, but is not limited to, protective gases such as hydrogen, argon, helium, and nitrogen; gases required for growth such as hydrogen, nitrogen, oxygen, methane, ammonia, acetylene, and ethylene; vapors required for growth such as ethanol vapor, sulfur vapor, titanium tetrachloride vapor, and vanadium pentoxide vapor; and mixed gases.

[0135] The type of vacuum pump 52 is not specifically limited. Preferably, the vacuum pump 52 is equipped with a vacuum level indicator for monitoring and maintaining the vacuum level of the chamber. Different vacuum pumps 52 can be selected according to the different growth requirements of the two-dimensional material thin film on the vacuum level of the growth chamber 12, and multiple vacuum pumps 52, such as molecular vacuum pumps and mechanical vacuum pumps, can be used in combination.

[0136] In some embodiments, the growth system of the roll-to-roll continuous fabrication apparatus 10 for two-dimensional material thin films may further include a sealing flange 51 for static sealing of the growth chamber 12. The sealing flange 51 is installed at both ends of the growth chamber 12 and connected to the inlet end 13 and the outlet end 14, respectively, to form a sealed environment and ensure gas supply. A vacuum pump 52 is connected to the outlet end 14 to provide a certain negative pressure to the growth chamber 12.

[0137] See also Figure 1 and Figure 2 In some embodiments, the control system may include: a mobile platform 31 disposed on both sides of the growth chamber 12, for mounting motors 216 on the unwinding roller 21 and the take-up roller 22; a computer 34 configured to receive externally input commands and generate control instructions based on the received commands; and a controller 34 signal-connected to both the mobile platform 31 and the computer 34, configured to receive control instructions from the computer 34 and manipulate the mobile platform 31 according to the control instructions. Externally input commands may be, for example, user-input commands. The number of mobile platforms 31 may be the same as or different from the number of motors 216.

[0138] The motors are mounted on a movable platform 31 outside the growth chamber 12. Since each unwinding roller 21 and take-up roller 22 is equipped with two motors, and there are also two inner / outer rollers, the rotating shaft 211 can be stably suspended within the cross-section of the growth chamber 12 without any fixing device due to the dual-sided magnetic coupling force. Stable suspension is also one of the necessary conditions for the roller system to have movable properties.

[0139] When motor 216 starts, due to the magnetic coupling between the inner and outer wheels of the unwinding roller 21 and the take-up roller 22, and the fact that the inner wheel can rotate freely along the inner wall of the growth chamber, the inner wheel 213 and the shaft 211 also rotate accordingly. This means that power is transmitted non-contactly from the outside of the growth chamber 12 to its interior. When motor 216 moves along the outer wall of the growth chamber 12, due to the magnetic coupling between the inner and outer wheels of the unwinding roller 21 and the take-up roller 22, and the fact that the inner wheel can move freely along the inner wall of the growth chamber, the positions of the inner wheel 213 and the shaft 211 can move accordingly. This means that the effect of external operation can be directly transmitted non-contactly to the interior of the growth chamber 12.

[0140] Figure 6 This is a schematic diagram of the structure of a mobile platform 31 according to an embodiment of the present invention. See also... Figure 6 As shown, in some embodiments, the mobile platform 31 includes a platform 311, a stepper motor 312, a slide rail 313, and a support 314 (e.g., Figure 6 (As shown). Platform 311 is used to place stepper motor 312 and mount slide rail 313. Slide rail 313 is located in the horizontal direction along the axial direction of growth chamber 12, and bracket 314 is mounted on it. Stepper motor 312 is used to push and pull bracket 314 to move along slide rail 313. Bracket 314 is used to fix the motors 216 of unwinding roller 21 and take-up roller 22, so that the positions of the motors of unwinding roller 21 and take-up roller 22 can be moved along slide rail 313 under the operation of stepper motor 312 of moving platform 31.

[0141] The substrate 23 serves as the substrate for catalytic growth and winding of the two-dimensional material thin film. Its length is determined by experimental requirements and equipment parameters and is not limited. Optionally, the length of the substrate 23 is less than 10 cm. Optionally, the length of the substrate 23 is ≥10 cm. Optionally, the length of the substrate 23 is 1 m to 10 km. Preferably, the length of the substrate 23 is 1 m to 2 m. The material of the substrate 23 is determined by requirements and is not limited; it can be selected according to different growth requirements of the two-dimensional material thin film.

[0142] Preferably, the substrate 23 is flexible.

[0143] Optionally, the substrate 23 may be a substrate with catalytic growth properties, commonly referred to as a growth substrate, including but not limited to commonly used metal foils and inorganic non-metallic sheets. The metal foils include, but are not limited to, copper, nickel, zinc, copper-nickel alloys, copper-zinc alloys, tungsten, molybdenum, tantalum, titanium, chromium, manganese, iron, cobalt, silver, platinum, and gold; the inorganic non-metallic sheets include, but are not limited to, silicon, silicon dioxide, silicon carbide, silicon nitride, silicates, quartz, glass, alumina, aluminum nitride, and sapphire.

[0144] Optionally, substrate 23 can be a flexible substrate that does not participate in the catalytic growth of the thin film, referred to here as an auxiliary substrate, including commonly used flexible high-temperature resistant substrates. Optionally, the flexible high-temperature resistant substrate includes, but is not limited to, graphite paper, carbon fiber cloth, corundum fiber paper, ceramic fiber paper, mica cloth, etc. Such substrates usually serve a supporting function, or an isolating function, or both; or they may have more functions, such as providing source materials for the growth of two-dimensional material thin films in addition to these supporting and isolating functions.

[0145] Optionally, substrate 23 can be a composite substrate, generally referring to a substrate that includes a growth substrate and an auxiliary substrate in some form. For example, a growth substrate of a certain length is arranged on top of another, longer auxiliary substrate, or multiple growth substrates are arranged at intervals. The growth substrate can be flexible or rigid. When the growth substrate is rigid, the growth substrate is not rolled up, and the auxiliary substrate mainly plays a transport role.

[0146] In some further embodiments, the control system may also include a displacement sensor 32, which is signal-connected to a computer 34 and configured to detect the initial position information of the shafts 211 of the unwinding roller 21 and the take-up roller 22 and the substrate 23 before the roll-to-roll transport process and the real-time position information during the roll-to-roll transport process, and send the initial position information and the real-time position information to the computer 34. The computer 34 is also configured to determine the lateral offset and tension state of the substrate 23 based on the initial position information and the real-time position information, and generate control commands based on the lateral offset and tension state and transmit them to the controller 33, so that the controller 33 can manipulate the moving platform 31 according to the control commands to drive the unwinding roller 21 and / or the take-up roller 22 to complete the correction and tension adjustment of the substrate 23.

[0147] Specifically, displacement sensor 32 is used to return real-time position information of the spindle 211 and substrate 23 during roll-to-roll transport to the computer. Computer 34 receives the real-time position information returned by displacement sensor 32, compares it with the initial position information, determines the lateral offset and tension state of substrate 23, monitors substrate 23, and transmits instructions to controller 33 after analyzing and processing the monitoring results. Controller 33 controls the moving platform 31 according to the instructions of computer 34, so that unwinding roller 21 or take-up roller 22 completes the correction of substrate 23 and tension adjustment.

[0148] The displacement sensor 32 can be located outside the unwinding area 121 and the winding area 123 of the growth chamber, close to the shaft 211 of the unwinding roller 21 and the winding roller 22, and is used to return real-time position information of the shaft 211 and the substrate 23 to the computer 34. The type of displacement sensor 32 depends on the equipment requirements, including but not limited to photoelectric displacement sensors, ultrasonic displacement sensors, infrared displacement sensors, laser displacement sensors, etc.

[0149] like Figure 1 As shown, the initial position information and real-time position information include information in the x, y, and z directions, where the x-direction is the axial direction of the shaft 211 of the unwinding roller 21 or the take-up roller 22, the y-direction is the substrate conveying direction, and the z-direction is the vertical direction. Specifically, the required position information includes the initial and real-time positions of the shaft 211 of the unwinding roller 21 and the take-up roller 22 in the substrate conveying direction (i.e., the y-direction), the initial and real-time positions of the substrate 23 at the shaft 211 of the take-up roller 22 in the axial direction of the shaft 211, and the initial and real-time positions of the substrate 23 in the vertical direction at a predetermined distance from the center line of the shaft of the unwinding roller 21 or the take-up roller 22.

[0150] Preferably, each displacement sensor 32 includes three probes: a first probe for returning the position information in the y-direction of the rotation axis; a second probe for returning the position information in the x and z directions of one side of the substrate 23 (referred to as side A for ease of description); and a third probe for returning the position information in the x and z directions of the other side of the substrate 23 (referred to as side B for ease of description).

[0151] Accordingly, in some specific embodiments, the displacement sensor 32 is configured to detect the initial and real-time positions (i.e., the x-direction positions of the substrate on the A and B sides) of the substrate at the rotation axis 211 of the take-up roller 22 before and during roll-to-roll transport, and send them to the computer 34. The computer 34 is configured to calculate the difference between the initial and real-time positions of the substrate 23 at the rotation axis 211 of the take-up roller 22 as the lateral offset Δx of the substrate 23, and when |Δx| is greater than or equal to a preset lateral offset threshold, determine the side of the growth cavity 12 to which the substrate 23 is biased (e.g., the A side) based on the lateral offset Δx, and then generate corresponding control commands based on |Δx| and the side to which the substrate 23 is biased and send them to the controller 33. According to the control command, the controller 33 controls the moving platform 31, which is located on the other side (e.g., side B) of the growth cavity and corresponds to the take-up roller 22, to drive the motor 216 on the moving platform 31 to move a set distance Δd1 in the reverse direction along the substrate conveying direction. This causes the rotating shaft 211 of the take-up roller 22 to deviate from its axial direction by an angle Δθ through the magnetic attraction between the first cavity outer part and the first cavity inner part of the take-up roller 22, where Δd1 < |Δx|, tan(Δθ) = Δd1 / l, and l is the dimension of the growth cavity 12 in the axial direction of the rotating shaft 211. Subsequently, the displacement sensor 32, computer 34, and controller 33 repeatedly acquire the real-time position of the substrate 23 on the axial direction of the shaft 211 of the take-up roller 22, calculate the lateral offset Δx of the substrate 23, and control the moving platform 31, which is located on the other side of the growth chamber 12 and corresponds to the take-up roller 22, to move the motor 216 on the moving platform 31 in the opposite direction along the substrate conveying direction by a set distance Δd1 until |Δx| is less than the preset lateral offset threshold. Then, the moving platform 31 is controlled to drive the motor 216 of the take-up roller 22 back to its initial position. In this way, the substrate 23 is corrected.

[0152] In practical operation, a zero point (origin) and a positive direction in the x-direction can be set. Then, based on the sign of the difference Δx between the initial position and the real-time position of the substrate 23 at the rotation axis 211 of the take-up roller 22 in the axial direction of the rotation axis 211, the side to which the substrate is biased can be determined. For example, if side A in the x-direction is set as the positive direction, then when Δx is positive, the substrate 23 is determined to be biased towards side B, and when Δx is negative, the substrate 23 is determined to be biased towards side A.

[0153] Those skilled in the art will understand that when the growth chamber 12 is cylindrical, l is the diameter of the growth chamber 12; when the growth chamber 12 is square, l is the side length of the growth chamber 12 along the axial direction of the rotation axis 211.

[0154] In some specific embodiments, the displacement sensor 32 is configured to detect the initial and real-time positions of the shafts 211 of the unwinding roller 21 and the take-up roller 22 in the substrate conveying direction (i.e., the y-direction), and the initial and real-time positions of the substrate 23 in the vertical direction (i.e., the z-direction) at a predetermined distance from the center line of the shaft of the unwinding roller 21 or the take-up roller 22, and send these to the computer 34. The computer 34 is configured to calculate the difference between the initial and real-time positions of the substrate 23 in the vertical direction at a predetermined distance from the center line of the shaft of the unwinding roller or the take-up roller as the vertical change distance Δz of the substrate, and when the vertical change distance Δz is greater than or equal to a preset vertical change distance threshold, determine that the tension of the substrate 23 is insufficient, and generate a corresponding control command and send it to the controller 33. The controller 33 is configured to control the moving platforms 31 on both sides corresponding to one of the unwinding roller 21 and the take-up roller 22 to simultaneously drive the motor 216 of that one to move horizontally a set distance Δd2 away from the other, where Δd2 < Δz, according to the control command. Subsequently, the displacement sensor 32, computer 34, and controller 33 repeatedly acquire the real-time position of the substrate in the vertical direction at a predetermined distance from the center line of the unwinding or take-up roller, calculate the vertical change distance Δz, and control the moving platforms on both sides corresponding to one of the unwinding and take-up rollers to simultaneously drive the motor of that roller to move horizontally a set distance Δd2 away from the other roller, until the vertical change distance Δz is less than the preset vertical change distance threshold.

[0155] Computer 34 is further configured to calculate the difference between the initial and real-time positions of the shafts of the unwinding and take-up rollers in the substrate conveying direction as the longitudinal offset Δy of the shafts, and when the longitudinal offset Δy of either the unwinding or take-up roller shaft is greater than a preset longitudinal offset threshold, determine that the tension of the substrate 23 is too large, and generate a corresponding control command to send to controller 33. Controller 33 is further configured to, according to the control command, control the moving platforms 31 on both sides corresponding to one of the unwinding and take-up rollers to simultaneously drive the motor 216 of that roller to move horizontally a set distance Δd3 along the direction closer to the other roller, where Δd3 < Δy. Subsequently, the displacement sensor 32, computer 34, and controller 33 repeatedly acquire the real-time position of the unwinding and take-up rollers' shafts in the substrate conveying direction, calculate the longitudinal offset Δy of the shafts, and control the moving platforms on both sides corresponding to one of the unwinding and take-up rollers to simultaneously drive the motor of that roller to move horizontally a set distance Δd3 closer to the other roller, until the longitudinal offset Δy of both the unwinding and take-up rollers' shafts is less than a preset longitudinal offset threshold. This achieves tension adjustment of the substrate 23.

[0156] The preset lateral offset threshold, preset vertical change distance threshold, and preset longitudinal offset threshold can be set according to actual application requirements, for example, they can be set to 0. The predetermined distance from the center line of the shaft of the unwinding roller 21 or the take-up roller 22 can be set according to the actual situation, preferably so that the displacement sensor 32 can sensitively and accurately sense the substrate position and the substrate position change is relatively obvious.

[0157] Figure 7 This is a schematic diagram of correcting the substrate 23 according to an embodiment of the present invention; Figure 8 This is a schematic diagram of adjusting the tension of substrate 23 according to an embodiment of the present invention. The following is in conjunction with... Figure 7 and Figure 8 The mechanism of the correction and tension adjustment of the present invention will be explained.

[0158] In some specific embodiments, before roll-to-roll transport begins, the position information of the spindle 211 and the substrate 23 must first be initialized. The first probe detection point of the displacement sensor 32 is positioned at the edge of the spindle 211, at a distance of 0-2mm from the edge (i.e., the allowable offset); the second probe detection point is positioned at the A-side edge of the substrate 23, at a distance of 0-2mm from the edge; and the third probe detection point is positioned at the B-side edge of the substrate 23, at a distance of 0-2mm from the edge.

[0159] During roll-to-roll transport, displacement sensor 32 returns real-time position information of the spindle 211 and substrate 23 to computer 34, including the horizontal position information of spindle 211 in the y-direction, and the horizontal position information of substrate 23 in the x-direction and the vertical position information in the z-direction. Computer 34 compares the real-time position information of substrate 23 with its initial position information to determine the position offset of substrate 23, thereby realizing real-time position monitoring of substrate 23.

[0160] When computer 34 detects that the position of substrate 23 has shifted along the rotation axis (i.e., the x-direction) to side A (B) (e.g.) Figure 7 As shown in (a), after analyzing the signal, the computer 34 sends a corresponding command to the controller 33 according to the offset Δx. The controller 33 controls the B(A) side moving platform 31 to start and drive the take-up roller 22 motor 216 to move a certain distance Δd1 in the opposite direction along the substrate 23 conveying direction. Due to the magnetic coupling between the inner and outer wheels of the take-up roller 22, the inner wheel of the take-up roller 22 will drive the rotating shaft to deviate from the axial direction by a certain angle Δθ (e.g., ...). Figure 7 As shown in (b), at this time the substrate 23 will be wound towards the B(A) side (as shown in (b)). Figure 7 As shown in (c), monitoring and control of movement are performed simultaneously. When the computer 34 detects that the substrate 23 has shifted to 0 along the rotation axis, the computer 34 sends a command to the controller 33, causing the B(A) side moving platform 31 to drive the take-up roller 22 motor back to its original parallel position (as shown in (c)). Figure 7As shown in (d), this achieves the correction of the substrate 23.

[0161] When computer 34 detects a change of Δz in the position of substrate 23 along the vertical direction (i.e., the z-direction), it corresponds to insufficient tension in substrate 23 and downward bending (e.g., ...). Figure 8 As shown in (a), after analyzing the signal, the computer 34 sends a corresponding command to the controller 33 according to the degree of position change. The controller 33 controls the A-side and B-side moving platforms 31 to start simultaneously and drive the take-up roller 22 (or unwind roller 21) motor to move a certain distance Δd2 in a direction away from the unwind roller 21 (or take-up roller 22). Due to the magnetic coupling between the inner and outer rollers, the distance between the rotation axes of the take-up roller 22 and the unwind roller 21 on the winding substrate 23 increases (e.g., as shown in (a)). Figure 8 As shown in (b), the substrate 23 is then re-tensioned.

[0162] When computer 34 detects that the position of the rotating shaft deviates from the magnetic coupling center, that is, when the position of the rotating shaft shifts by Δy in the y-direction, it corresponds to excessive tension on substrate 23 (e.g., Figure 8 As shown in (c), after analyzing the signal, the computer 34 sends a corresponding command to the controller 33 based on the shaft position offset. The controller 33 controls the A-side and B-side moving platforms 31 to start simultaneously and drive the take-up roller (or unwind roller) motor to move a certain distance Δd3 in the direction close to the unwind roller (or take-up roller). The shafts of the take-up roller and unwind roller that are wound around the substrate 23 return to the magnetic coupling center position (as shown in (c)). Figure 8 As shown in (d), the substrate 23 is in force balance and the tension returns to normal.

[0163] In embodiments of the present invention, displacement sensors detect the initial position information of the unwinding and take-up rollers and the substrate before the roll-to-roll transport process, as well as the real-time position information during the roll-to-roll transport process. Based on this initial and real-time position information, the moving platform is controlled, which drives the unwinding and / or take-up rollers to move, thereby completing the substrate alignment and tension adjustment. Thus, only two drive rollers are needed to achieve multiple functions such as substrate winding, unwinding, automatic alignment, tension adjustment, and stress distribution control, improving the reliability and practicality of the equipment and further reducing the complexity and cost of the device. Furthermore, since this alignment and tension adjustment method does not require the establishment of friction between the substrate and the roller surface, it causes almost no damage to the two-dimensional material film on the substrate.

[0164] Based on the same technical concept, this embodiment of the invention also provides a method for continuous roll-to-roll preparation of two-dimensional material thin films using the aforementioned roll-to-roll continuous preparation apparatus 10.

[0165] Figure 12 This is a schematic flowchart of a roll-to-roll continuous fabrication method for two-dimensional material thin films according to an embodiment of the present invention. See also... Figure 12 As shown, the roll-to-roll continuous fabrication method for the two-dimensional material thin film includes at least the following steps S1202 to S1210:

[0166] Step S1202: After the substrate is wound onto the shaft of the unwinding roller and one end of the substrate is connected to the shaft of the take-up roller, the shafts of the unwinding roller and the take-up roller, together with the substrate, are placed horizontally suspended inside the growth chamber by magnetically attracting the inner and outer portions of the first cavity of each of the unwinding roller and the take-up roller.

[0167] Step S1204: Turn on the vacuum pump to create a vacuum environment in the growth chamber;

[0168] Step S1206: Turn on the heating unit and heat the growth chamber to the preset growth temperature;

[0169] Step S1208: Introduce the raw materials required for the growth of two-dimensional materials into the growth chamber;

[0170] Step S1210: Control the movement of the unwinding roller and the take-up roller to perform roll-to-roll transport of the substrate, thereby growing a two-dimensional material thin film on the substrate.

[0171] Specifically, in step S1202, the shaft of the unwinding roller 21 is removed from the unwinding area 121 of the growth chamber. The substrate 23 is wound around it and then returned to the unwinding area 121, so that the inner and outer wheels of the unwinding roller 21 form a magnetic coupling. The shaft and the substrate 23 are horizontally suspended inside the growth chamber 12. The shaft of the take-up roller 22 is removed from the take-up area 123. The other end of the substrate 23 is pulled out from the unwinding area 121, through the growth area 122 and the take-up area 123, and connected to the shaft of the take-up roller 22. Then, the shaft of the take-up roller 22 is sent back to the take-up area 123, so that the inner and outer wheels of the take-up roller 22 form a magnetic coupling. The shaft connected to the substrate 23 is horizontally suspended inside the growth chamber. The motor of the take-up roller 22 is started. After the substrate 23 is tensioned, the motor of the take-up roller 22 is then turned off.

[0172] In step S1204, before evacuating, the flanges 51 at both ends of the growth chamber 12 are tightened to seal the growth chamber. Then, the molecular vacuum pump 52 is turned on, and the pressure in the growth chamber 12 can be reduced to 10⁻⁵ mbar and maintained, indicating that there is no additional leakage or venting in the growth chamber. At this point, the molecular vacuum pump 52 can be turned off, and the rotary vane vacuum pump 52 can be turned on to maintain the pressure in the growth chamber below 1 mbar.

[0173] In step S1206, protective gas is introduced from the gas inlet 13, and the heating unit 11 is turned on to heat the growth chamber.

[0174] In step S1208, after the growth chamber temperature reaches the growth temperature, a protective gas is introduced while the gas required for the growth of the two-dimensional material is introduced from the gas inlet 13 (when the gas source 4 is steam, the steam raw material is placed in the constant temperature zone inside the growth chamber 12). The gas can be a mixture.

[0175] In step S1210, the unwinding roller 21 and the winding roller 22 are started and started. According to the time required for the growth of the two-dimensional material film, the substrate 23 is rolled up and transported at a certain speed. The status of the substrate 23 and the rotating shaft 211 is monitored in real time by the control system, and the substrate 23 is automatically corrected and the tension is adjusted to ensure the stable and continuous preparation of the two-dimensional material film.

[0176] In some optional embodiments, the roll-to-roll continuous fabrication method of the two-dimensional material thin film further includes:

[0177] After growth is complete, the heating unit 11 is turned off, the roll-to-roll transfer of the substrate 23 is stopped, and the growth chamber is cooled to room temperature. Then, the gas source 4 and vacuum pump 52 are turned off, the growth chamber is opened, and a two-dimensional material film / substrate 23 is obtained on the take-up roller 22.

[0178] In some embodiments, the roll-to-roll continuous fabrication apparatus 10 for two-dimensional material thin films includes: a moving platform 31 disposed on both sides of a growth chamber for placing motors thereon, the number of moving platforms being the same as the number of motors; and a displacement sensor 32 configured to detect the initial position information of the unwinding roller and the winding roller and the substrate before the roll-to-roll conveying process and the real-time position information during the roll-to-roll conveying process. The roll-to-roll continuous fabrication method for two-dimensional material thin films further includes:

[0179] Before starting roll-to-roll transfer of the substrate, obtain the initial position information of the unwinding and rewinding rollers and the substrate.

[0180] During the roll-to-roll transfer of the substrate, the real-time position information of the unwinding and rewinding rollers and the substrate is acquired. Based on the initial position information and the real-time position information, the lateral offset and tension state of the substrate are determined. Based on the lateral offset and tension state, the moving platform is controlled to drive the unwinding and rewinding rollers to move, thereby completing the correction of the substrate and the adjustment of the tension force.

[0181] In some further embodiments, the initial position information and real-time position information include the initial position and real-time position of the substrate at the axis of the take-up roller in the axial direction of the axis.

[0182] During the roll-to-roll transfer of the substrate, the real-time position information of the unwinding and take-up rollers and the substrate is acquired. Based on the initial position information and the real-time position information, the lateral offset and tension state of the substrate are determined. The moving platform is then controlled to move the unwinding and take-up rollers according to the lateral offset and tension state, thereby completing the steps of substrate correction and tension adjustment. The substrate correction operation includes:

[0183] Obtain the real-time position of the substrate at the axis of the winding roller in the axial direction of the axis;

[0184] The difference between the initial position and the real-time position of the substrate at the axis of the winding roller in the axial direction is calculated as the lateral offset Δx of the substrate.

[0185] When |Δx| is greater than or equal to the preset lateral offset threshold, the side of the growth cavity to which the substrate is biased is determined according to the lateral offset Δx. The moving platform corresponding to the take-up roller and set on the other side of the growth cavity is controlled to drive the motor on the moving platform to move in the opposite direction along the substrate conveying direction by a set distance Δd1. Thus, through the magnetic attraction between the first cavity outer part and the first cavity inner part of the take-up roller, the rotating shaft of the take-up roller is driven to deviate from its axial direction by an angle Δθ, where Δd1<|Δx|, tan(Δθ)=Δd1 / l, and l is the dimension of the growth cavity in the axial direction of the rotating shaft.

[0186] Repeatedly acquire the real-time position of the substrate at the shaft of the take-up roller in the axial direction of the shaft, calculate the lateral offset Δx of the substrate, and control the moving platform corresponding to the take-up roller, which is located on the other side of the growth chamber, to drive the motor on the moving platform to move in the opposite direction of the substrate conveying direction by a set distance Δd1 until |Δx| is less than the preset lateral offset threshold, and then control the moving platform to drive the motor of the take-up roller back to its initial position.

[0187] In some further embodiments, the initial position information and real-time position information also include the initial and real-time positions of the unwinding and take-up rollers in the substrate conveying direction, and the initial and real-time positions of the substrate in the vertical direction at a predetermined distance from the center line of the unwinding or take-up roller's axis.

[0188] During the roll-to-roll transfer of the substrate, the real-time position information of the unwinding and take-up rollers and the substrate is acquired. Based on the initial position information and the real-time position information, the lateral offset and tension state of the substrate are determined. The moving platform is then controlled to move the unwinding and take-up rollers according to the lateral offset and tension state, thereby completing the steps of substrate correction and tension adjustment. The operation of adjusting the substrate tension includes:

[0189] The real-time position of the unwinding roller and the winding roller in the substrate conveying direction, and the real-time position of the substrate in the vertical direction at a predetermined distance from the center line of the unwinding roller or the winding roller.

[0190] The difference between the initial position and the real-time position of the substrate in the vertical direction at a predetermined distance from the center line of the unwinding or winding roller is calculated as the vertical change distance Δz of the substrate.

[0191] When the vertical change distance Δz is greater than or equal to the preset vertical change distance threshold, the control of the moving platforms on both sides corresponding to one of the unwinding roller and the winding roller simultaneously drives the motor of that roller to move horizontally a set distance Δd2 away from the other roller, where Δd2 < Δz.

[0192] Repeatedly acquire the real-time position of the substrate in the vertical direction at a predetermined distance from the center line of the rotation axis of the unwinding roller or the take-up roller, calculate the vertical change distance Δz, and control the moving platforms on both sides corresponding to one of the unwinding roller and the take-up roller to simultaneously drive the motor of that one to move horizontally a set distance Δd2 away from the other until the vertical change distance Δz is less than the preset vertical change distance threshold.

[0193] The difference between the initial and real-time positions of the unwinding and winding rollers in the substrate conveying direction is calculated as the longitudinal offset Δy of the rollers.

[0194] When the longitudinal offset Δy of either the unwinding roll or the take-up roll is greater than the preset longitudinal offset threshold, the moving platforms on both sides corresponding to one of the unwinding roll and the take-up roll are controlled to simultaneously drive the motor of that one to move horizontally a set distance Δd3 in the direction closer to the other, where Δd3 < Δy.

[0195] Repeatedly acquire the real-time position of the unwinding roller and the take-up roller shaft in the substrate conveying direction, calculate the longitudinal offset Δy of the shaft, and control the moving platforms on both sides corresponding to one of the unwinding roller and the take-up roller to simultaneously drive the motor of that one to move horizontally a set distance Δd3 in the direction closer to the other until the longitudinal offset Δy of the shaft of both the unwinding roller and the take-up roller is less than the preset longitudinal offset threshold.

[0196] Specifically, during roll-to-roll transport, displacement sensor 32 continuously monitors the position information of substrate 23. When the position of substrate 23 is detected to have shifted along the direction A(B) of the winding roller 22 shaft 221, computer 34 analyzes the signal and sends a corresponding command to controller 33 based on the offset Δx. Controller 33 controls the B(A) side moving platform 31 to start and drive the winding roller 22 motor 216 to move a certain distance Δd1 in the opposite direction of substrate 23 transport. Due to the magnetic coupling between the inner and outer wheels of the winding roller 22, the inner wheel of the winding roller 22 will drive the shaft to deviate axially by a certain angle Δθ. At this time, substrate 23 will be wound towards the B(A) side. When computer 34 detects that the offset of substrate 23 along the direction of shaft 211 is 0, computer 34 sends a command to controller 33 to make the B(A) side moving platform 31 drive the winding roller 22 motor 216 back to the original parallel position, thereby realizing the correction of substrate 23.

[0197] When the position of substrate 23 changes by Δz in the vertical direction (i.e., the z-direction), it corresponds to insufficient tension of substrate 23 and downward bending. After analyzing the signal, computer 34 sends a corresponding instruction to controller 33 according to the degree of position change. Controller 33 controls the A-side and B-side moving platforms 31 to start simultaneously and drive the take-up roller 22 (or unwind roller 21) motor to move a certain distance Δd2 in a direction away from unwind roller 21 (or take-up roller 22). Due to the magnetic coupling between the inner and outer rollers, the distance between the rotating shafts of the take-up roller 22 and the unwind roller 21 that are winding substrate 23 increases, so substrate 23 is re-tensioned.

[0198] When the position of the rotating shaft deviates from the magnetic coupling center, that is, when the position of the rotating shaft shifts by Δy in the y direction, it corresponds to excessive tension on the substrate 23. After analyzing the signal, the computer 34 sends a corresponding command to the controller 33 based on the position offset of the rotating shaft. The controller 33 controls the A-side and B-side moving platforms 31 to start simultaneously and drive the take-up roller (or unwind roller) motor to move a certain distance Δd3 in the direction close to the unwind roller (or take-up roller). The rotating shafts on the take-up roller 21 and unwind roller 22 that are winding around the substrate 23 return to the position of the magnetic coupling center. Thus, the substrate 23 is in force balance and the tension returns to normal.

[0199] The following detailed description of the two-dimensional material thin film roll-to-roll continuous preparation apparatus 10 and method of the present invention is provided through specific embodiments.

[0200] Example 1: Continuous preparation method of graphene thin film

[0201] (1) First, in the substrate assembly process, since the roll-to-roll drive system is placed separately inside and outside the growth chamber, there is no hard connection between the inner and outer structures. They are coupled only by magnetic force. Therefore, when assembling and removing the substrate, the internal structure can be directly removed for operation and then directly put back. The operation is simple and convenient. Specifically, the shaft 211 of the unwinding roller 21 is directly taken out from the unwinding area 121 of the growth chamber 12. The substrate 23 is wound on it and then directly sent back to the unwinding area 121, so that the inner and outer wheels of the unwinding roller 21 form magnetic coupling. The shaft 211 and the substrate 23 are horizontally suspended inside the growth chamber 12. The shaft 211 of the take-up roller 22 is removed from the take-up area 123. The other end of the substrate 23 is pulled out from the unwinding area 121, through the growth area 122 and the take-up area 123, and connected to the shaft 211 of the take-up roller 22. Then, the shaft 211 of the take-up roller 22 is sent back to the take-up area 123, so that the inner and outer wheels of the take-up roller 22 form magnetic coupling. The shaft 211, connected to the substrate 23, is horizontally suspended inside the growth chamber 12. The motor 216 of the take-up roller 22 is started. After the substrate 23 is tensioned, the motor 216 of the take-up roller 22 is then turned off. The growth chamber 12 is preferably a quartz tube with a length of 120cm and a diameter of 5cm. The unwinding area 121 and the winding area 123 are 20cm long, and the growth area 122 is 30cm long. There is one unwinding roller 21 and one winding roller 22. The rotating shaft 211 is a quartz rod. The inner wheel 213 is a stainless steel spherical cap with a diameter of 4.5cm and a height of 1cm. The surface is mechanically polished. There are 10 inner magnets 212 arranged on the outer edge of the inner wheel 213. The inner magnet is made of neodymium iron boron alloy. The outer wheel 215 is a polypropylene disc with a diameter of 2cm and a height of 0.5cm. There are 10 outer magnets 214 arranged on the outer edge of the outer wheel 215. The outer magnet is made of neodymium iron boron alloy. The substrate 23 is preferably a meter-sized commercially available high-purity copper foil.

[0202] (2) Tighten the flanges 51 at both ends of the growth chamber 12 to seal the growth chamber 12. Since the growth chamber adopts a static sealing method and there are no additional motors or other equipment placed inside the growth chamber, the placement of the roll-to-roll drive system will not have an additional impact on the vacuum environment of the growth chamber.

[0203] (3) Turn on the molecular vacuum pump 52; the pressure in the growth chamber can be as low as 10. -5 The pressure was maintained at 1 mbar, demonstrating that the growth chamber had no additional leakage or outgassing and could meet the experimental requirements of high vacuum. The molecular vacuum pump 52 was turned off, and the rotary vane vacuum pump 52 was turned on to maintain the pressure in the growth chamber below 1 mbar.

[0204] (4) Hydrogen and argon are introduced from the gas inlet 13, and the heating unit 11 is turned on to heat the growth chamber 12. The hydrogen flow rate is preferably 30 sccm and the argon flow rate is preferably 100 sccm; the heating mode is single-temperature zone heating.

[0205] (5) After the growth chamber 12 reaches the growth temperature, hydrogen and argon are introduced simultaneously, and methane is introduced from the gas inlet 13 to grow graphene. The growth temperature is between 900℃ and 1080℃, preferably 1030℃, and the methane flow rate is preferably 1 sccm.

[0206] (6) Simultaneously start the unwinding roller 21 and the winding roller 22. According to the time required for the growth of graphene film, the substrate 23 is rolled up and transported at a certain speed. The status of the substrate 23 and the rotating shaft is monitored in real time by the control system. The substrate 23 is automatically corrected and the tension is adjusted to ensure that the graphene film is prepared stably and continuously.

[0207] In this embodiment, the roll-to-roll drive system consists of only two rollers: an unwind roller 21 and a take-up roller 22. However, because the roller system of this invention has movable properties, the unwind roller 21 and take-up roller 22 not only have the basic functions of unwinding and rewinding the substrate 23, but can also automatically correct the deviation and adjust the tension of the substrate 23 through the novel deviation correction and tension adjustment method of this invention. In contrast, traditional take-up / unwind rollers are often fixedly installed and therefore do not have such functions.

[0208] Specifically, during roll-to-roll transport, displacement sensor 32 continuously monitors the position information of substrate 23. When it detects that the position of substrate 23 has shifted along the A(B) side of the winding roller 22 shaft axis 211 (e.g....), the sensor will detect the shift. Figure 7 In (a), after analyzing the signal, the computer 34 sends a corresponding command to the controller 33 based on the offset. The controller 33 controls the B(A) side moving platform 31 to start and drive the take-up roller motor 216 to move a certain distance in the opposite direction along the substrate 23 conveying direction. Due to the magnetic coupling between the inner and outer wheels of the take-up roller 22, the inner wheel 213 of the take-up roller 22 will drive the rotating shaft 211 to deviate from the axial direction by a certain angle (e.g., Figure 7 In (b)), at this time the substrate 23 will be wound towards the B(A) side (as shown in the image). Figure 7 In the middle (c)), when the displacement sensor 32 detects that the substrate 23 has shifted 0 along the direction of the rotation axis 211, the computer 34 sends a command to the controller 33 to cause the B(A) side moving platform 31 to drive the take-up roller motor 216 back to the original parallel position (e.g., Figure 7 In the middle (d), the bias correction of substrate 23 is achieved.

[0209] When the displacement sensor 32 detects a change in the position of the substrate 23 along the vertical direction, it corresponds to insufficient tension in the substrate 23 and downward bending (e.g. Figure 8In (a), after analyzing the signal, the computer 34 sends a corresponding command to the controller 33 based on the degree of position change. The controller 33 controls the simultaneous start of the moving platforms 31 on sides A and B, driving the motors of the take-up roller 22 (unwind roller 21) to move a certain distance away from the unwind roller 21 (take-up roller 22). Due to the magnetic coupling between the inner and outer rollers, the distance between the rotating shafts of the substrate 23 wound on the take-up roller 22 and the unwind roller 21 increases (e.g., ...). Figure 8 In (b)), the substrate 23 is then re-tensioned. When the displacement sensor 32 detects that the position of the rotating shaft deviates from the magnetic coupling center, it corresponds to excessive tension on the substrate 23 (e.g., Figure 8 In the middle (c), after analyzing the signal, the computer 34 sends a corresponding command to the controller 33 according to the shaft position offset. The controller 33 controls the A-side and B-side moving platforms 31 to start simultaneously and drive the take-up roller (unwind roller) motor to move a certain distance along the direction close to the unwind roller 21 (take-up roller 22). The shafts of the take-up roller 22 and unwind roller 21 that are wound around the substrate 23 return to the magnetic coupling center position (e.g., Figure 8 In the middle (d)), the substrate 23 is in force balance, and the tension returns to normal.

[0210] Real-time correction and tension adjustment of substrate 23 ensures smooth and normal unwinding and rewinding processes, preventing substrate 23 from drooping and bending due to insufficient tension, which would cause wrinkles and misalignment during rewinding; substrate 23 from breaking due to excessive tension, which would lead to rewinding failure; and substrate 23 from misalignment, which would cause wrinkles or even rewinding failure.

[0211] The rotational speeds of the unwinding roller 21 and the winding roller 22 are between 0.5 RMP and 5 RMP, preferably 1 RMP.

[0212] (7) After growth is completed, turn off the heating unit 11 and stop the roll-to-roll transfer of the substrate 23. After the growth chamber 12 cools to room temperature, turn off the gas source 4 and vacuum pump 52, open the growth chamber 12, and directly remove the internal structure of the take-up roller 22 to obtain a graphene film / copper foil that is flatly wound on the take-up roller shaft 211.

[0213] This embodiment ultimately yielded a graphene film grown on copper foil with a characteristic length in the meter range, free of macroscopic wrinkles and cracks, and smoothly rolled up. Figure 13 As shown in (a), the prepared graphene film was transferred onto a SiO2 / Si substrate using polymethyl methacrylate (PMMA) assisted transfer for characterization. The scanning electron microscope image is shown below. Figure 14 As shown, graphene is mainly monolayered, with a small amount of bilayer and multilayered graphene islands, the scale of which is about 1-5 μm. Raman spectral images are shown below. Figure 16 As shown in the figure, the prepared graphene film is a high-quality monolayer graphene film with few defects.

[0214] Example 2: Continuous preparation method of graphene-carbon nanotube composite films

[0215] (1) Remove the shaft 211 of the unwinding roller 21 from the unwinding area 121 of the growth chamber 12, wind the substrate 23 onto it, and return it to the unwinding area 121, so that the inner and outer wheels of the unwinding roller 21 form a magnetic coupling, and the shaft and the substrate 23 are horizontally suspended inside the growth chamber 12. Remove the shaft 211 of the take-up roller 22 from the take-up area 123, pull out the other end of the substrate 23 from the unwinding area 121 through the growth area 122 and the take-up area 123 and connect it to the shaft 211 of the take-up roller 22, and then send the shaft 211 of the take-up roller 22 back to the take-up area 123, so that the inner and outer wheels of the take-up roller 22 form a magnetic coupling, and the shaft 211 connected to the substrate 23 is horizontally suspended inside the growth chamber 12. Start the motor 216 of the take-up roller 22, and after the substrate 23 is tensioned, turn off the motor 216 of the take-up roller 22. The growth chamber 12 is preferably a quartz tube with a length of 120cm and a diameter of 5cm, wherein the unwinding area 121 and the winding area 123 are 20cm long, and the growth area 122 is 30cm long; there is one unwinding roller 21 and one winding roller 22; the rotating shaft 211 is a quartz rod; the inner wheel 213 is a stainless steel spherical crown with an outer diameter of 4.5cm, an inner diameter of 4cm, and a height of 1cm, and the surface is mechanically polished; the number of inner magnets 212 arranged on the outer edge of the inner wheel 213 is 10, and the material is neodymium iron boron alloy; the outer wheel 215 is a polypropylene disk with a diameter of 2cm and a height of 0.5cm; the number of outer magnets 214 arranged on the outer edge of the outer wheel 215 is 10, and the material is neodymium iron boron alloy; the substrate 23 is preferably a meter-sized commercially available high-purity copper foil covered with a carbon nanotube film.

[0216] (2) Tighten the flanges 51 at both ends of the growth chamber 12 to seal the growth chamber 12.

[0217] (3) Turn on the molecular vacuum pump 52; the pressure in the growth chamber can be as low as 10. -5 The pressure in the growth chamber remained below 1 mbar, indicating that there was no additional leakage or venting. The molecular vacuum pump 52 was turned off, and the rotary vane vacuum pump 52 was turned on, maintaining the pressure in the growth chamber below 1 mbar.

[0218] (4) Hydrogen and argon are introduced from the gas inlet 13, and the heating unit 11 is turned on to heat the growth chamber 12. The hydrogen flow rate is preferably 40 sccm and the argon flow rate is preferably 100 sccm; the heating mode is single-temperature zone heating.

[0219] (5) After the growth chamber 12 reaches the growth temperature, hydrogen and argon are introduced simultaneously, and methane is introduced from the gas inlet 13 to grow graphene. The growth temperature is between 900℃ and 1080℃, preferably 1030℃, and the methane flow rate is preferably 1.5 sccm.

[0220] (6) Same as Example 1

[0221] (7) After growth is completed, turn off the heating unit 11 and stop the roll-to-roll transfer of the substrate 23. After the growth chamber 12 cools to room temperature, turn off the gas source 4 and vacuum pump 52, open the growth chamber 12, and obtain a graphene-carbon nanotube composite film / copper foil that is flat and wound on the winding roller 22.

[0222] This embodiment ultimately yielded a graphene-carbon nanotube composite film grown on copper foil, exhibiting a smooth, meter-long characteristic length without macroscopic wrinkles or cracks, and with a flat, rolled-up surface. Figure 13 As shown in (b), the prepared graphene-carbon nanotube composite film was transferred onto a SiO2 / Si substrate for a series of performance characterizations. The images obtained under a scanning electron microscope are shown below. Figure 15 As shown, the pore size of the carbon nanotube network is approximately 2 μm. Graphene fills the pores of the carbon nanotube network, and the graphene within the pores is completely filled. The graphene in the pores is primarily monolayered, with a small amount of bilayer and multilayered graphene islands. These bilayer and multilayered graphene islands are approximately 1-2 μm in size, comparable to the pore size of the carbon nanotube network. Raman spectral images are shown below. Figure 16 As shown in the figure, the prepared graphene-carbon nanotube composite film retains the intrinsic properties of carbon nanotubes and graphene, and has fewer defects, making it a high-quality graphene-carbon nanotube composite film.

[0223] Example 3: Continuous preparation method of molybdenum disulfide thin film

[0224] (1) The solid raw material for the steam source required for growth is placed in a quartz boat and sent into the first temperature zone of the growth zone 122 of the growth chamber. The growth zone 122 is a dual-temperature zone heating mode. The shaft 211 of the unwinding roller 21 is taken out from the unwinding zone 121 of the growth chamber 12. The substrate 23 is wound on it and sent back to the unwinding zone 121, so that the inner and outer wheels of the unwinding roller 21 form a magnetic coupling. The shaft and the substrate 23 are horizontally suspended inside the growth chamber 12. The shaft 211 of the winding roller 22 is taken out from the winding zone 123. The other end of the substrate 23 is pulled out from the unwinding zone 121 through the growth zone 122 and the winding zone 123 and connected to the shaft 211 of the winding roller 22. Then the shaft 211 of the winding roller 22 is sent back to the winding zone 123, so that the inner and outer wheels of the winding roller 22 form a magnetic coupling. The shaft 211 connected to the substrate 23 is horizontally suspended inside the growth chamber 12. Start the motor 216 of the take-up roller 22, and after the substrate 23 is tensioned, turn off the motor 216 of the take-up roller 22. The growth chamber 12 is preferably a quartz tube with a length of 120cm and a diameter of 5cm. The unwinding zone 121 and the winding zone 123 are 20cm long, the growth zone 122 is 30cm long, the first temperature zone is 5cm long, the second temperature zone is 20cm long, and the first and second temperature zones are 5cm apart. There is one unwinding roller 21 and one winding roller 22. The rotating shaft 211 is a quartz rod. The inner wheel 213 is a stainless steel spherical cap with a diameter of 4.5cm and a height of 1cm, and its surface is mechanically polished. There are 10 inner magnets 212 arranged on the outer edge of the inner wheel 213, and the material is neodymium iron boron alloy. The outer wheel 215 is a polypropylene disc with a diameter of 2cm and a height of 0.5cm. There are 10 outer magnets 214 arranged on the outer edge of the outer wheel 215, and the material is neodymium iron boron alloy. The substrate 23 is preferably meter-sized carbon fiber cloth coated with a molybdenum layer. The solid raw material for the steam source required for growth is sulfur powder with a mass of 50g.

[0225] (2) Tighten the flanges 51 at both ends of the growth chamber 12 to seal the growth chamber 12.

[0226] (3) Turn on the molecular vacuum pump 52; the pressure in the growth chamber can be as low as 10. -5 The pressure in the growth chamber remained below 1 mbar, indicating that there was no additional leakage or venting. The molecular vacuum pump 52 was turned off, and the rotary vane vacuum pump 52 was turned on, maintaining the pressure in the growth chamber below 1 mbar.

[0227] (4) Argon gas is introduced from the gas inlet 13, and the heating unit 11 is turned on to heat the first and second temperature zones of the growth chamber 12 respectively. The preferred argon gas flow rate is 100 sccm.

[0228] (5) After the temperature of the growth chamber 12 reaches the growth temperature, argon gas is used as a carrier gas to transport sulfur vapor to the second temperature zone to grow molybdenum disulfide. The temperature of the first temperature zone needs to be greater than the melting point of sulfur, preferably 120°C, and the temperature of the second temperature zone is between 650°C and 850°C, preferably 780°C.

[0229] (6) Same as in Example 1. The rotational speeds of the unwinding roller 21 and the winding roller 22 are between 0.1 RMP and 5 RMP, preferably 0.5 RMP.

[0230] (7) After growth is completed, turn off the heating unit 11, stop the roll-to-roll transfer of the substrate 23, wait for the growth chamber 12 to cool to room temperature, turn off the gas source 4 and vacuum pump 52, open the growth chamber 12, and obtain a molybdenum disulfide film / carbon fiber cloth that is flat and wound on the winding roller 22.

[0231] This embodiment ultimately yields a molybdenum disulfide film grown on carbon fiber cloth that is free of macroscopic wrinkles and cracks and has a smooth, rolled-up surface.

[0232] Example 4: Continuous preparation method of graphene thin film

[0233] This embodiment provides a preferred structure for a mobile platform.

[0234] (1)-(5) Same as Example 1

[0235] (6) Simultaneously start the unwinding roller 21 and the winding roller 22. According to the time required for graphene film growth, the substrate 23 is rolled up and transported at a certain speed. The status of the substrate 23 and the rotating shaft is monitored in real time by the control system. The control system automatically corrects the substrate 23 and adjusts the tension by controlling the movement of the moving platform 31 to ensure the stable and continuous preparation of the graphene film.

[0236] In this embodiment, the mobile platform 31 includes a platform 311, a stepper motor 312, a slide rail 313, and a support 314 (e.g., ...). Figure 6 (As shown). Platform 311 is used to place stepper motor 312 and mount slide rail 313. Slide rail 313 is located in the horizontal direction along the axial direction of growth chamber 12, and bracket 314 is mounted on it. Stepper motor 312 is used to push and pull bracket 314 to move along slide rail 313. Bracket 314 is used to fix the motors 216 of unwinding roller 21 and take-up roller 22, so that the positions of the motors of unwinding roller 21 and take-up roller 22 can be moved along slide rail 313 under the operation of stepper motor 312 of moving platform 31.

[0237] Specifically, during roll-to-roll transport, displacement sensor 32 continuously monitors the position information of substrate 23. When it detects that the position of substrate 23 has shifted along the direction A(B) of the winding roller 22 shaft 221 (e.g., ...), the sensor detects that the position of substrate 23 has shifted. Figure 7In (a), after analyzing the signal, the computer 34 sends a corresponding command to the controller 33 based on the offset. The controller 33 controls the stepper motor 312 on the B (A) side to start and drive the take-up roller 22 motor 216 on the support 314 to move a certain distance in the opposite direction along the substrate 23 conveying direction. Due to the magnetic coupling between the inner and outer wheels of the take-up roller 22, the inner wheel 213 of the take-up roller 22 will drive the rotating shaft 211 to deviate from the axial direction by a certain angle (e.g., Figure 7 In (b) of the above, at this time the substrate 23 will be wound towards the B(A) side (as shown in the image). Figure 7 In (c) of the diagram, when the displacement sensor 32 detects that the substrate 23 has shifted 0 along the direction of the rotation axis 211, the computer 34 sends a command to the controller 33 to cause the stepper motor 312 on the B(A) side to drive the take-up roller 22 motor 216 back to its original parallel position (e.g., ...). Figure 7 (d) in the middle, thereby realizing the correction of substrate 23.

[0238] When the displacement sensor 32 detects a change in the position of the substrate 23 along the vertical direction, it corresponds to insufficient tension in the substrate 23 and downward bending (e.g. Figure 8 In (a), after analyzing the signal, the computer 34 sends a corresponding command to the controller 33 based on the degree of position change. The controller 33 controls the stepper motors 312 on both sides A and B to start simultaneously and drive the motor 216 of the take-up roller 22 (or unwind roller 21) on the support 314 to move a certain distance away from the unwind roller 21 (or take-up roller 22). Due to the magnetic coupling between the inner and outer rollers, the distance between the rotating shafts of the take-up roller 22 and the unwind roller 21 that are winding the substrate 23 increases (e.g., ...). Figure 8 (b) in the diagram, thus the substrate 23 is re-tensioned. When the displacement sensor 32 detects that the position of the rotating shaft deviates from the magnetic coupling center, it corresponds to excessive tension on the substrate 23 (e.g., ...). Figure 8 In (c) of the diagram, after analyzing the signal, the computer 34 sends a corresponding command to the controller 33 based on the shaft position offset. The controller 33 controls the stepper motors 312 on both sides A and B to start simultaneously and drive the take-up roller 22 (or unwind roller 21) motor on the support 314 to move a certain distance in a direction close to the unwind roller 21 (or take-up roller 22). The shafts on the take-up roller 22 and unwind roller 21 that are winding the substrate 23 return to the magnetic coupling center position (e.g., ...). Figure 8 In (d)), the substrate 23 is in force balance, and the tension returns to normal.

[0239] The rotational speeds of the unwinding roller 21 and the winding roller 22 are between 0.5 RMP and 5 RMP, preferably 1 RMP.

[0240] (7) After growth is completed, turn off the heating unit 11, stop the roll-to-roll transfer of the substrate 23, wait for the growth chamber 12 to cool to room temperature, turn off the gas source 4 and vacuum pump 52, open the growth chamber 12, and obtain a graphene film / copper foil that is flatly wound on the winding roller 22.

[0241] This embodiment ultimately yielded a graphene film with a characteristic length in the meter range, grown on copper foil without macroscopic wrinkles or cracks and with a smooth, rolled-up surface, achieving the same effect as in Embodiment 1.

[0242] Example 5: Continuous preparation method of graphene thin film

[0243] This embodiment uses manual correction and tension adjustment.

[0244] (1)-(5) Same as Example 1

[0245] (6) Simultaneously start the unwinding roller 21 and the winding roller 22. Based on the time required for graphene film growth, the substrate 23 is uniformly wound and transported at a certain speed, and the state of the substrate 23 and the rotating shaft is manually monitored. As high-temperature growth proceeds, the surface of the substrate 23 gradually transforms into a molten state and deforms. Under the action of gravity, the substrate 23 elongates and falls (e.g., ...). Figure 8 In (a)), at this time, the entire motor 216 of the take-up roller 22 is manually moved a certain distance away from the unwind roller 21. Due to the magnetic coupling between the inner and outer rollers, the distance between the rotating shafts of the take-up roller 22 and the unwind roller 21 on the winding substrate 23 increases (e.g., Figure 7 In (b) of the above, substrate 23 is re-tensioned. As the roll-to-roll transport proceeds, it is found that the position of substrate 23 shifts to side A along the direction of the shaft 211 of take-up roller 22 (e.g., ...). Figure 7 In (a)), at this time, the motor 216 of the take-up roller 22 on side B is manually moved a certain distance in the opposite direction along the conveying direction of the substrate 23. Due to the magnetic coupling between the inner and outer wheels of the take-up roller 22, the inner wheel 213 of the take-up roller 22 drives the rotating shaft 211 to deviate from the axial direction by a certain angle (e.g., Figure 7 In (b) of the above, at this time the substrate 23 is wound towards side B (as shown in the image). Figure 7 In (c) of the diagram, when the substrate 23 is offset to 0 along the direction of the rotating shaft 211, the B-side take-up roller 22 and motor 216 are moved back to their original parallel position (e.g., ...). Figure 7 In step (d), the substrate 23 is corrected. Throughout the roll-to-roll transport process, the substrate 23 is manually corrected and tension adjusted in real time to ensure stable and continuous fabrication of the graphene film. The rotational speeds of the unwinding roller 21 and the take-up roller 22 are between 0.5 RMP and 5 RMP, preferably 1 RMP.

[0246] (7) After growth is completed, turn off the heating unit 11, stop the roll-to-roll transfer of the substrate 23, wait for the growth chamber 12 to cool to room temperature, turn off the gas source 4 and vacuum pump 52, open the growth chamber 12, and obtain a graphene film / copper foil that is flatly wound on the winding roller 22.

[0247] This embodiment ultimately yielded a graphene film with a characteristic length in the meter range, grown on copper foil without macroscopic wrinkles or cracks and with a smooth, rolled-up surface, achieving the same effect as in Embodiment 1.

[0248] Example 6: Mass Continuous Preparation Method of Graphene Films

[0249] (1) Take the shaft 211 of the unwinding roller 21 out of the unwinding area 121 of the growth chamber 12, wind the substrate 23 onto it and send it back to the unwinding area 121, so that the inner and outer wheels of the unwinding roller 21 form a magnetic coupling, and the shaft and the substrate 23 are horizontally suspended inside the growth chamber 12. Take the shaft 211 of the take-up roller 22 out of the take-up area 123, and pass the other end of the substrate 23 around the shaft 241 of the guide roller 24 of the unwinding area 121, pass through the growth area 122, pass around the shaft 241 of the guide roller 24 in the take-up area 123 and connect it to the shaft 211 of the take-up roller 22. Then send the shaft 211 of the take-up roller 22 back to the take-up area 123, so that the inner and outer wheels of the take-up roller 22 form a magnetic coupling, and the shaft 211 connected to the substrate 23 is horizontally suspended inside the growth chamber 12. Start the motor 216 of the take-up roller 22, and after the substrate 23 is tensioned, immediately turn off the motor 216 of the take-up roller 22. The growth chamber 12 is preferably a quartz square tube with a length of 140cm. The unwinding area 121 and the take-up area 123 have lengths, widths, and heights of 20cm, 10cm, and 20cm, respectively, while the growth area 122 has lengths, widths, and heights of 20cm, 10cm, and 10cm, respectively. The roller system within the growth chamber 12 is arranged as follows: Figure 2 As shown, there are two unwinding rollers 21 and two winding rollers 22, and four guide rollers 24; the rotating shaft 211 and the guide roller shaft 241 are polytetrafluoroethylene rods; the inner wheels 213 and 243 are polytetrafluoroethylene discs with quartz balls embedded in the center, wherein the disc diameter of the inner wheel 213 is 5cm, the disc diameter of the inner wheel 243 is 2cm, the height of both is 0.5cm, the diameter of the balls is 0.4cm, and the surface is treated with high temperature melting; the inner wheels 213 have inner magnets 2 arranged on the outer edge. The number of inner magnets 242 arranged on the outer edge of the inner wheel 243 is 20, and the number of inner magnets 242 arranged on the outer edge of the inner wheel 243 is 10. All of them are made of high-purity iron. The outer wheels 215 and 245 are polypropylene discs, with the outer wheel 215 having a diameter of 5cm and the outer wheel 245 having a diameter of 2cm, and both having a height of 0.5cm. The number of outer magnets 214 arranged on the outer edge of the outer wheel 215 is 20, and the number of outer magnets 244 arranged on the outer edge of the outer wheel 245 is 10. All of them are made of neodymium iron boron alloy. The substrate 23 is preferably a meter-sized commercially available high-purity copper foil.

[0250] (2) Tighten the flanges 51 at both ends of the growth chamber 12 to seal the growth chamber 12.

[0251] (3) Turn on the molecular vacuum pump 52; the pressure in the growth chamber can be as low as 10. -5The pressure in the growth chamber remained below 1 mbar, indicating that there was no additional leakage or venting. The molecular vacuum pump 52 was turned off, and the rotary vane vacuum pump 52 was turned on, maintaining the pressure in the growth chamber below 1 mbar.

[0252] (4) Hydrogen and argon are introduced from the gas inlet 13, and the heating unit 11 is turned on to heat the growth chamber 12. The hydrogen flow rate is preferably 50 sccm and the argon flow rate is preferably 120 sccm; the heating mode is single-temperature zone heating.

[0253] (5) After the growth chamber 12 reaches the growth temperature, hydrogen and argon are introduced simultaneously, and methane is introduced from the gas inlet 13 to grow graphene. The growth temperature is between 950℃ and 1080℃, preferably 1030℃, and the methane flow rate is preferably 2 sccm.

[0254] (6) Same as Example 1

[0255] (7) After growth is completed, turn off the heating unit 11 and stop the roll-to-roll transfer of the substrate 23. After the growth chamber 12 cools to room temperature, turn off the gas source 4 and vacuum pump 52, open the growth chamber 12, and obtain two rolls of graphene film / copper foil that are flatly wound on the winding roller 22.

[0256] This embodiment ultimately yields two rolls of graphene film grown on copper foil, with a characteristic length in the meter range, free of macroscopic wrinkles and cracks, and smoothly rolled up, achieving the same effect as in Embodiment 1.

[0257] According to one or more embodiments of the present invention, the roll-to-roll continuous fabrication apparatus and method for two-dimensional material thin films of the present invention can achieve the following beneficial effects:

[0258] 1. Increase the vacuum level of the cavity

[0259] Since the quality of two-dimensional material films is extremely sensitive to the vacuum level of the growth chamber, maintaining the vacuum level of the growth chamber during production is a key factor in ensuring the quality of two-dimensional material films. This invention uses a non-contact magnetic drive device instead of a traditional contact drive device, avoiding additional leakage and gas release to the growth chamber caused by installing a drive device, and maintaining the vacuum environment of the chamber to the greatest extent.

[0260] The non-contact magnetic drive device of this invention, on the one hand, compared with the method of internal roller system, external motor and hole installation, does not require hole installation, transforms dynamic sealing into static sealing, makes the leakage caused by the installation of the drive device in the cavity zero, and avoids the complicated maintenance process required for long-term use of dynamic seals. On the other hand, compared with the installation method of internal roller system and motor, this invention not only places some roller system components outside the growth cavity, but also places only a small part of the roller system components inside the growth cavity. More importantly, it places the large power system outside the growth cavity, thereby avoiding the outgassing of the power system components under the heat radiation of the growth cavity, and greatly reducing the vacuum space required to place the drive device. Since the larger the volume of the vacuum cavity occupied, the more leakage and outgassing occur, and the more difficult it is to achieve and maintain the vacuum degree inside the growth cavity, the method provided by this invention is more conducive to the realization and maintenance of the vacuum degree of the growth cavity than the traditional method. It ensures that the growth of two-dimensional material films is not affected by cavity leakage and outgassing during roll-to-roll production, and is more conducive to avoiding external impurities and atmospheres, which helps to improve the quality and purity of two-dimensional material films.

[0261] 2. The roll-to-roll drive roller system of the present invention has a simple structure, is lightweight and small in size, and requires no fixed installation; it can be directly placed at both ends of the growth chamber. The internal structure of the roller system is suspended inside the growth chamber by the double-sided magnetic coupling force provided by the external structure, and the inner wheel in the internal structure is in contact with the inner wall of the growth chamber without any connection. The inner and outer wheels of the roller system are respectively placed on the inner and outer sides of the growth chamber wall in the unwinding / rewinding area, and there is also no rigid connection between the inner and outer wheels; power transmission is achieved through magnetic coupling force.

[0262] This invention employs a special shape design and surface treatment for the inner wheel. Specifically, the inner wheel is designed in shapes such as spherical crowns, cones, and discs with central balls to adapt to different shapes of growth chambers. The surface treatment of the inner wheel can be selected using different methods depending on the material, including high-temperature melting, mechanical polishing, and electrochemical polishing.

[0263] Compared to traditional methods, this design eliminates the need for fixed installation of the roller system. No additional vacuum chambers are required at either end of the growth chamber to securely mount all the rollers. This avoids leakage at the connection between the growth chamber and the vacuum chamber, and significantly reduces the complexity of the equipment, installation difficulty, and manufacturing costs. Furthermore, for growth chambers of different shapes and sizes, since fixed installation is not required, the roll-to-roll drive roller system of this invention can be directly applied simply by changing the dimensions of the shaft and inner wheel, broadening the application scenarios of the device and improving its versatility and practicality.

[0264] 3. Movable attribute

[0265] Traditional devices that rely on magnetic force for power transmission are primarily magnetic couplings. Magnetic couplings also consist of internal and external structures. The internal structure mainly comprises a fixed bearing and an inner wheel that rotates on this fixed shaft. The external structure mainly consists of a power system and an outer wheel connected to the power system. Magnets are arranged on both the inner and outer wheels, forming magnetic coupling, thereby transmitting power from the outside to the inside through magnetic coupling. For example... Figure 11 As shown, if traditional magnetic couplings are directly applied to roll-to-roll continuous production systems, a fixed shaft needs to be installed inside the growth chamber to meet the working conditions of the magnetic coupling.

[0266] This invention employs dual-sided magnetic coupling power transmission and a specially designed inner roller system, enabling the roll-to-roll drive roller system to be movable without fixed installation. Mobility includes horizontal movement of the roller system as a whole, opposite movement, and reverse movement; rotation of the roller system in a vertical plane; and relative movement of the motors within the roller system. These mobility methods greatly enhance the flexibility of the device, giving it numerous functions and advantages not found in traditional roll-to-roll drive systems.

[0267] 4. Automatic deviation correction and tension adjustment

[0268] The growth temperature of two-dimensional (2D) thin films can often reach thousands of degrees Celsius. For the metal substrates used for catalytic growth of 2D thin films, the surface is often already in a molten state. Furthermore, the thickness of the metal foil used as the substrate is generally on the order of micrometers. Therefore, geometric deformation inevitably occurs after the growth process. In the mass production of 2D thin films, the geometric deformation of the substrate, coupled with the error in the parallel arrangement between the roll-to-roll drive rollers, makes changes in substrate tension and lateral displacement during the winding process a common occurrence.

[0269] Traditional web-aligning rollers and tension-adjusting rollers require friction between the substrate and the roller surface during web alignment and tension adjustment, which inevitably causes damage or even delamination of the two-dimensional material films grown on the substrate. Furthermore, traditional web-aligning rollers still require dynamic seals or built-in motors for installation and necessitate guide rollers, making installation complex and space-consuming. Ordinary tension-adjusting rollers can only provide specific tension to the substrate; achieving digital and controllable adjustment of substrate tension requires even more complex structures.

[0270] The roll-to-roll drive roller system of the present invention has movable properties, and under the operation of the control system, it can realize real-time automatic correction and tension adjustment of the substrate, avoiding (1) substrate sagging and bending caused by insufficient tension, resulting in substrate deviation and wrinkling during the winding process; (2) substrate 23 breakage caused by excessive tension, resulting in winding failure; (3) substrate wrinkling or even winding failure caused by substrate deviation. Even in the mass production process of substrates with a length of thousands of meters, the flatness and stable winding of the substrate can be ensured.

[0271] Furthermore, the novel correction and tension adjustment mechanism of the present invention does not require the establishment of friction between the substrate and the roller surface, and will not cause any damage to the two-dimensional material film on the substrate. It can realize digital controllable adjustment of correction and tension. Moreover, since no roller system is added, no additional space is required, which greatly reduces the complexity and cost of the device.

[0272] 5. In actual production, especially during sample loading and unloading, the roller system's rotating shaft can be freely removed, making operation very convenient. Furthermore, since two-dimensional material films are often grown in high-temperature and low-pressure environments, the growth process inevitably leads to substrate volatilization, especially severe volatilization of metal foil. Consequently, metal films can deposit inside the growth chamber, at the ports, and even in the external vacuum chamber. If the same type of metal film substrate is being transferred, only periodic cleaning and maintenance of the growth chamber are needed to prevent excessive or uneven deposition of the metal film from affecting the growth chamber environment. If different types of substrates need to be transferred, the equipment chamber must be cleaned and maintained before each growth cycle to prevent further volatilization and contamination of other substrates. Cleaning and maintenance of the equipment chamber typically involves acid washing, mechanical polishing, or electrochemical polishing, requiring disassembly and reassembly of the equipment. Because the roll-to-roll drive roller system of this invention is not fixedly installed within the equipment chamber, it is movable and offers installation flexibility, making disassembly and reassembly during cleaning and maintenance very convenient, greatly reducing the difficulty of equipment maintenance.

[0273] 6. Scalability

[0274] The roll-to-roll continuous fabrication apparatus of this invention uses non-contact transmission to separate the internal and external environments of the cavity, eliminating interference. Furthermore, the controllable winding / unwinding process under system control, along with automatic deviation correction and tension adjustment, makes this roll-to-roll continuous fabrication apparatus highly practical. Moreover, this roll-to-roll continuous fabrication apparatus can be used not only for fabricating two-dimensional material thin films but also for the roll-to-roll fabrication of other materials; it is applicable not only to LPCVD systems but also to APCVD, OPCVD, ultra-high vacuum CVD (UHCVD), plasma-enhanced CVD (PECVD), physical vapor deposition (PVD), and molecular beam epitaxy (MBE) systems. Maintaining the cavity vacuum level is particularly crucial for systems like UHCVD and MBE that require ultra-high vacuum.

[0275] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0276] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A roll-to-roll continuous fabrication apparatus for two-dimensional material thin films, comprising: The growth system includes: Heating unit; The growth chamber includes a growth zone corresponding to the heating unit, as well as an unwinding zone and a winding zone; and A vacuum pump is configured to create a vacuum environment within the growth chamber. A roll-to-roll drive system includes an unwinding roller disposed in the unwinding zone and a take-up roller disposed in the take-up zone, the unwinding roller and the take-up roller being configured to unwind and take up a substrate for growing a two-dimensional material film thereon, respectively; and The control system is configured to control the movement of the unwinding roller and the take-up roller; characterized in that, Both the unwinding roller and the winding roller include a first inner cavity portion disposed within the growth chamber and a first outer cavity portion disposed outside the growth chamber. The first inner cavity portion includes a rotating shaft for winding the substrate, and the first outer cavity portion includes a motor for driving the rotating shaft to rotate. The first inner cavity portion and the first outer cavity portion of each of the unwinding roller and the winding roller are magnetically attracted to each other to movably place the unwinding roller and the winding roller at both ends of the growth chamber. Each of the unwinding roller and the winding roller includes a first cavity inner portion and two first cavity outer portions. The two first cavity outer portions are symmetrically placed on both sides of the growth cavity corresponding to the first cavity inner portion to provide a double-sided magnetic attraction effect for the first cavity inner portion. Each of the first cavity portions further includes: two inner wheels, respectively fixed to both ends of the rotating shaft, with at least a portion of each inner wheel in contact with the inner wall of the growth cavity; and two sets of inner magnets, respectively disposed on the two inner wheels, each set of inner magnets including at least one inner magnet; Each of the first cavity external portions further includes: an outer wheel, positioned corresponding to the position of the corresponding inner wheel, at least a portion of the outer wheel contacting the outer wall of the growth cavity, and the motor connected to the outer wheel; and a set of outer magnets including at least one outer magnet, arranged on the outer wheel in a manner opposite in position to and with opposite magnetic poles to a set of inner magnets on the corresponding inner wheel.

2. The roll-to-roll continuous fabrication apparatus for two-dimensional material thin films according to claim 1, wherein, The shapes of the inner wheel and the outer wheel are configured such that their projections on a plane perpendicular to the axis of rotation match. Each group of inner magnets and each group of outer magnets that attract each other includes the same number of inner magnets and outer magnets. The inner magnets in each group of inner magnets are arranged on the outer edge of the inner wheel in an alternating manner with magnetic poles, and the outer magnets in each group of outer magnets are arranged on the outer edge of the outer wheel in an alternating manner with magnetic poles.

3. The roll-to-roll continuous fabrication apparatus for two-dimensional material thin films according to claim 1 or 2, wherein, The control system includes: A mobile platform is provided on both sides of the growth chamber for placing the motor thereon; A computer configured to receive commands from external input and generate control instructions based on the received commands; and The controller is connected to both the mobile platform and the computer via signals, and is configured to receive control commands from the computer and operate the mobile platform according to the control commands.

4. The roll-to-roll continuous fabrication apparatus for two-dimensional material thin films according to claim 3, wherein, The control system further includes: A displacement sensor, connected to the computer signal, is configured to detect the initial position information of the unwinding roller and the winding roller and the substrate before the roll-to-roll conveying process and the real-time position information during the roll-to-roll conveying process, and to send the initial position information and the real-time position information to the computer. The computer is further configured to determine the lateral offset and tension state of the substrate based on the initial position information and the real-time position information, and generate control commands based on the lateral offset and tension state and transmit them to the controller, so that the controller can manipulate the moving platform according to the control commands to drive the unwinding roller and / or the winding roller to complete the correction and tension adjustment of the substrate.

5. The roll-to-roll continuous fabrication apparatus for two-dimensional material thin films according to claim 1 or 2, wherein, The number of each of the unwinding roller and the winding roller is one or more; The roll-to-roll drive system also includes: One or more guide rollers, disposed in the unwinding area and / or the winding area, are used to change the conveying direction of the substrate; wherein Each of the guide rollers is fixedly installed in the unwinding area and / or the winding area; or Each of the guide rollers includes a second inner cavity portion containing a rotating shaft placed inside the growth cavity and a second outer cavity portion placed outside the growth cavity. The second inner cavity portion and the second outer cavity portion magnetically attract each other to non-fixedly place the guide roller in the unwinding area and / or the winding area.

6. A method for continuous roll-to-roll preparation of two-dimensional material thin films, performed using the apparatus for continuous roll-to-roll preparation of two-dimensional material thin films according to any one of claims 1-5, the preparation method comprising: After the substrate is wound onto the shaft of the unwinding roller and one end of the substrate is connected to the shaft of the take-up roller, the shafts of the unwinding roller and the take-up roller, together with the substrate, are placed horizontally suspended inside the growth chamber by magnetically attracting the first cavity inner portion and the first cavity outer portion of each of the unwinding roller and the take-up roller. The vacuum pump is turned on to create a vacuum environment within the growth chamber; Turn on the heating unit and heat the growth chamber to the preset growth temperature; The raw materials required for the growth of two-dimensional materials are introduced into the growth chamber; The movement of the unwinding roller and the take-up roller is controlled to perform roll-to-roll transport of the substrate, thereby growing a two-dimensional material thin film on the substrate; The two-dimensional material thin film roll-to-roll continuous preparation apparatus includes: a moving platform disposed on both sides of the growth cavity for placing the motor thereon, the number of moving platforms being the same as the number of motors; and a displacement sensor configured to detect the initial position information of the unwinding roller and the winding roller and the substrate before the roll-to-roll conveying process and the real-time position information during the roll-to-roll conveying process. The preparation method further includes: Before starting the roll-to-roll transfer of the substrate, the rotation shafts of the unwinding roller and the take-up roller and the initial position information of the substrate are obtained. During the roll-to-roll transfer of the substrate, the real-time position information of the unwinding roller and the take-up roller and the substrate is acquired. Based on the initial position information and the real-time position information, the lateral offset and tension state of the substrate are determined. Based on the lateral offset and tension state, the moving platform is controlled to drive the unwinding roller and the take-up roller to move, thereby completing the correction and tension adjustment of the substrate.

7. The method for continuous roll-to-roll preparation of two-dimensional material thin films according to claim 6, wherein, The initial position information and the real-time position information include the initial position and the real-time position of the substrate at the axis of the winding roller in the axial direction of the axis. In the process of roll-to-roll conveying the substrate, the real-time position information of the unwinding roller and the take-up roller and the substrate is acquired. Based on the initial position information and the real-time position information, the lateral offset and tension state of the substrate are determined. Based on the lateral offset and tension state, the moving platform is controlled to move the unwinding roller and the take-up roller to complete the correction and tension adjustment of the substrate. The step of correcting the substrate includes: Obtain the real-time position of the substrate at the axis of rotation of the take-up roller in the axial direction of the axis; The difference between the initial position and the real-time position of the substrate at the axis of the take-up roller in the axial direction of the axis is calculated as the lateral offset of the substrate. ; when When the horizontal offset is greater than or equal to a preset horizontal offset threshold, according to the horizontal offset Determine one side of the growth cavity to which the substrate is biased, and control the moving platform, which is located on the other side of the growth cavity and corresponds to the take-up roller, to drive the motor on the moving platform to move in the opposite direction along the substrate conveying direction by a set distance. Thus, the magnetic attraction between the outer part and the inner part of the first cavity of the take-up roller causes the shaft of the take-up roller to deviate from its axial direction by an angle. ,in , l is the dimension of the growth chamber in the axial direction of the rotating shaft; Repeatedly acquire the real-time position of the substrate at the axis of rotation of the take-up roller in the axial direction of the axis, and calculate the lateral offset of the substrate. And control the moving platform, which is located on the other side of the growth chamber and corresponds to the take-up roller, to drive the motor on the moving platform to move in the opposite direction along the substrate conveying direction by a set distance. The operation, until When the offset is less than the preset lateral offset threshold, the moving platform is controlled to drive the motor of the take-up roller back to its initial position.

8. The method for continuous roll-to-roll preparation of two-dimensional material thin films according to claim 6 or 7, wherein, The initial position information and the real-time position information also include the initial and real-time positions of the shafts of the unwinding roller and the winding roller in the substrate conveying direction, and the initial and real-time positions of the substrate in the vertical direction at a predetermined distance from the center line of the shaft of the unwinding roller or the winding roller. In the process of roll-to-roll conveying the substrate, the real-time position information of the unwinding roller and the take-up roller and the substrate is acquired. Based on the initial position information and the real-time position information, the lateral offset and tension state of the substrate are determined. Based on the lateral offset and tension state, the moving platform is controlled to move the unwinding roller and the take-up roller to complete the correction and tension adjustment of the substrate. The operation of adjusting the tension of the substrate includes: The real-time position of the unwinding roller and the winding roller in the substrate conveying direction, and the real-time position of the substrate in the vertical direction at a predetermined distance from the center line of the unwinding roller or the winding roller's axis. The difference between the initial and real-time positions of the substrate in the vertical direction at a predetermined distance from the center line of the unwinding roller or the take-up roller is calculated as the vertical change distance of the substrate. ; When the vertical change distance When the vertical change distance is greater than or equal to a preset threshold, the moving platforms on both sides corresponding to one of the unwinding roller and the winding roller are controlled to simultaneously drive the motor of that roller to move horizontally a set distance away from the other roller. ,in ; Repeatedly acquire the real-time vertical position of the substrate at a predetermined distance from the center line of the axis of rotation of the unwinding roller or the take-up roller, and calculate the vertical change distance. And control the moving platforms on both sides corresponding to one of the unwinding roll and the take-up roll to simultaneously drive the motor of that one to move horizontally a set distance away from the other. The operation continues until the vertical change distance is reached. Less than the preset vertical change distance threshold; The difference between the initial and real-time positions of the shafts of the unwinding roller and the take-up roller in the substrate conveying direction is calculated as the longitudinal offset of the shafts. ; When the longitudinal offset of the axis of either the unwinding roller or the winding roller When the longitudinal offset exceeds a preset threshold, the moving platforms on both sides corresponding to one of the unwinding roll and the take-up roll are controlled to simultaneously drive the motor of that roll to move horizontally a set distance closer to the other roll. ,in ; Repeatedly acquire the real-time positions of the unwinding roller and the take-up roller shafts in the substrate conveying direction, and calculate the longitudinal offset of the shafts. And control the moving platforms on both sides corresponding to one of the unwinding roll and the take-up roll to simultaneously drive the motor of that one roll to move horizontally a set distance in a direction closer to the other roll. The operation continues until the longitudinal offset of the axis of rotation of the unwinding roll and the take-up roll is achieved. All are less than the preset longitudinal offset threshold.

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