Roll-to-roll electrostatic printing device

Abstract

The invention provides a roll-to-roll electrostatic printing device which solves the technical problems that existing wet printing is low in precision and efficiency and high in cost, the device comprises a power part and a printing part internally provided with a mask plate, the power part drives a roll-shaped flexible substrate to penetrate through the printing part for electrostatic printing, and the mask plate is arranged on the printing part. The functional material penetrates through the dielectric area of the mask plate through the electric field generated in the printing component to be deposited on the flexible substrate, the printing precision is improved, the printing quality is guaranteed, meanwhile, binder-free printing is adopted, the characteristics of the functional material can be fully exerted, the environmental protection property is high, material consumption is reduced, cost is saved, and the production efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of printed electronics technology, and particularly relates to a roll-to-roll electrostatic printing device. Background Art

[0002] Currently, printed electronics mostly adopts techniques such as gravure printing, flexographic printing, screen printing, and inkjet printing to fabricate electronic devices on rigid or flexible substrates, such as fabricating flexible sensors and humidity sensors. These printing processes are all wet printing techniques, that is, before printing, functional materials need to be fully mixed with organic solvents, binders, etc. to form slurries and inks. This not only has poor environmental protection, but also increases material consumption and costs, with low material utilization rate. At the same time, it is also necessary to add a drying treatment step, which prolongs the production time and reduces the production efficiency.

[0003] The wet printing process also has many defects. For example, the rheological and spreading behaviors of the ink and the coffee ring effect will cause line width distortion of the pattern, limiting the printing accuracy and unable to guarantee the printing quality. The above problems greatly limit the improvement space of the wet printing process and make it difficult to achieve large-scale applications. Summary of the Invention

[0004] The purpose of the present invention is to solve the above technical deficiencies and provide a roll-to-roll electrostatic printing device.

[0005] To this end, the present invention provides a roll-to-roll electrostatic printing device, which includes a power component and a printing component with a mask plate inside. The power component drives a roll-shaped flexible substrate to pass through the printing component for electrostatic printing, and the functional material is deposited on the flexible substrate by penetrating the dielectric region of the mask plate using the electric field generated inside the printing component.

[0006] Preferably, the mask plate includes a conductive region and the dielectric region. The conductive region repels the electric field, and the dielectric region adopts a pre-patterned design and is filled with an insulating material.

[0007] Preferably, the printing component further includes a printing chamber, an electrode, and a feeder for placing the functional material. The electrode is suspended in the printing chamber and is located above the flexible substrate. The top of the feeder is open and is arranged at the bottom of the printing chamber. The mask plate is arranged between the flexible substrate and the feeder.

[0008] Preferably, the power component includes a motor and multiple roller shafts. The roller shafts are installed on a fixed frame. The motor is drivingly connected to one or more of the roller shafts. The flexible substrate is sequentially wound around the multiple roller shafts, and the printing chamber is arranged on the transmission path of the flexible substrate.

[0009] Preferably, the functional material includes graphene, carbon powder, nickel powder, iron powder and polymer material.

[0010] Preferably, a sensor for monitoring the tension is arranged on the transmission path of the flexible substrate, and the tension range of the flexible substrate is 70-175N.

[0011] Preferably, a door body is installed on the front of the printing chamber, and the door body is magnetically attracted to the printing chamber.

[0012] The beneficial effects of the present invention are as follows: The present invention provides a roll-to-roll electrostatic printing device, which has the following beneficial effects.

[0013] ⑴ It solves the problem that the use of wet printing has poor accuracy and the line width of the pattern is distorted due to ink rheology. A printing technology is adopted to directly deposit functional material particles on the flexible substrate by introducing an external electric field, so as to realize the rapid printing and preparation of high-performance micro-nano structures and electronic devices, improve the printing accuracy, and ensure the printing quality. Among them, the accuracy of the fabricated flexible sensor is improved, the signal transmission loss is reduced by 20%, the humidity sensor responds 5 milliseconds faster, and the sensitivity and accuracy are improved;

[0014] ⑵ The electric field generated by corona discharge can accelerate the deposition process of functional material particles. At the same time, binder-free printing is adopted, and the special properties of the functional material can be fully exerted, with strong environmental protection, reduced material consumption, cost savings, and improved production efficiency. Among them, the sensitivity of the fabricated flexible temperature sensor is increased by 15%. Due to the direct contact of the humidity sensor with the environment, the response speed is accelerated and the accuracy is increased by 23%, and the application scenario is broadened;

[0015] ⑶ The pattern of the dielectric region on the mask plate can be customized according to actual use requirements, promoting the production and manufacturing of fine electronic devices;

[0016] ⑷ It can use roll-to-roll equipment for large-scale production and manufacturing, accelerate the production efficiency of electronic devices, and promote the development of the printed electronics industry. Description of the Drawings

[0017] Figure 1 is the front structural schematic diagram of the roll-to-roll electrostatic printing device in the embodiment of the present invention;

[0018] Figure 2 is the structural schematic diagram of the electrode in the embodiment of the present invention;

[0019] Figure 3 is the back structural schematic diagram of the roll-to-roll electrostatic printing device in the embodiment of the present invention;

[0020] Figure 4 is the top view of the printing chamber in the embodiment of the present invention;

[0021] Figure 5 Yes Figure 4 It is a sectional view taken along the A-A direction in the figure.

[0022] Markings in the figure: 1. Flexible substrate; 2. Printing chamber; 3. Electrode; 4. Feeder; 5. Motor; 6. Roller; 61. Driving roller; 62. Guide roller; 7. Fixed frame; 8. Mounting bracket; 9. Support plate. Specific implementation mode

[0023] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments to help understand the content of the present invention. The methods used in the present invention are all conventional methods unless otherwise specified; the raw materials and devices used are all conventional commercially available products unless otherwise specified.

[0024] Embodiment:

[0025] As Figures 1 to 5 shown, the present invention provides a roll-to-roll electrostatic printing device, which includes a power component and a printing component with a mask plate inside. The power component drives a roll-shaped flexible substrate 1 to pass through the printing component for electrostatic printing. The flexible substrate 1 is a double-layer PET film, and the functional material is deposited on the flexible substrate 1 by penetrating the dielectric region of the mask plate using the electric field generated inside the printing component. The functional material includes graphene, carbon powder, nickel powder, iron powder, and polymer materials.

[0026] This embodiment will be elaborated from the following aspects respectively.

[0027] I. Power component.

[0028] The power component includes a motor 5 and a plurality of rollers 6. The rollers 6 are installed on a fixed frame 7. The fixed frame 7 is made of 8020 aluminum, providing stable support. It is light in weight and high in strength, facilitating the assembly and movement of the equipment. The motor 5 is drivingly connected to one or more of the rollers 6. The flexible substrate 1 is sequentially wound around the plurality of rollers 6, and the printing chamber 2 is arranged on the transmission path of the flexible substrate 1.

[0029] Specifically, the roller 6 includes a driving roller 61 and a plurality of guide rollers 62. The driving roller 61 and the guide rollers 62 are made of stainless steel, having good wear resistance and corrosion resistance, being able to adapt to the long-term transmission work of the flexible substrate 1, ensuring the smoothness of the surface of the roller 6, and reducing the frictional damage to the flexible substrate 1. The driving roller 61 is drivingly connected to the motor 5, and the motor 5 is used to precisely control the rotation of the driving roller 61. The guide rollers 62 play a role in guiding and supporting the flexible substrate 1 to ensure that the flexible substrate 1 remains stable during transmission.

[0030] Specifically, the motor 5 is a Taipu 4IK25RGN-C / 4GN12.5K controllable motor, which has the characteristic of high torque output and can meet the rotation requirements of the driving roller 61 under different load conditions. The motor 5 is directly connected to the driving roller 61 through a coupling to ensure the high efficiency and stability of power transmission. The motor 5 is fixedly installed on the mounting bracket 8, and the mounting bracket 8 is made of aluminum alloy material, which has good heat dissipation performance and can ensure the stability of the motor 5 during long-term operation.

[0031] II. Printing component.

[0032] The printing component includes a printing chamber 2, an electrode 3, and a feeder 4 for placing functional materials. The printing chamber 2 is a corona-assisted electrostatic printing chamber. The electrode 3 is used to generate an electric field to achieve electrostatic printing. The electrode 3 is suspended in the printing chamber 2 and is located above the flexible substrate 1. The top of the feeder 4 is open and is arranged at the bottom of the printing chamber 2. The mask plate is arranged between the flexible substrate 1 and the feeder 4 and is arranged closely against the flexible substrate 1.

[0033] The electrode 3 is suspended in the printing chamber 2, which can ensure the uniformity and stability of the electric field. At the same time, it can avoid the electric field interference and distortion caused by contact. The suspended design enables the position and angle of the electrode 3 to be conveniently adjusted to adapt to different printing requirements.

[0034] In this embodiment, the functional material is graphene. Graphene particles are placed in the feeder 4. The graphene particles are charged under the action of the electric field and are deposited on the flexible substrate 1 through the dielectric region of the mask plate. And the feeder 4 is close to the mask plate, and the graphene particles can smoothly enter the electric field region through the top opening of the feeder 4.

[0035] Further, the feeder 4 is placed on a tray, and the tray is slidably connected to the inner wall of the printing chamber 2 through a slide rail. The mask plate is also slidably connected to the inner wall of the printing chamber 2 through a slide rail. Since a door is installed on the front of the printing chamber 2, the door is magnetically attracted to the printing chamber 2. The magnetic attraction design facilitates the opening and closing of the door and is convenient for replacing the functional material and the mask plate. Therefore, the door can be opened according to actual needs, and thus the mask plate can be quickly replaced or graphene particles can be added to the feeder 4 under the action of the slide rail, greatly improving the working efficiency.

[0036] The printing chamber 2 adopts a magnetically attracted acrylic box. The acrylic material ensures its good insulation performance and is beneficial to the stability of the electric field. The sharp electrode 3 pin is suspended and installed in the printing chamber 2 through an external connecting frame, etc. The electrode 3 is connected to an external power supply through a wire.

[0037] III. Mask plate.

[0038] The mask plate is a thin plate with a specific pattern made of a conductive metal (such as copper or aluminum). The pattern area includes a conductive area and the dielectric area. The conductive areas are connected by circuits to form a specific electric field distribution, and the dielectric area is filled or covered with an insulating material (such as ceramic or polymer material). The thickness and size of the mask plate are designed according to the specifications of the printing chamber 2 and the printing accuracy requirements.

[0039] Furthermore, the mask plate is installed inside the printing chamber 2 and fixed on the pallet 9 by means of a card slot or magnetic attraction to ensure the stable position of the mask plate during printing without displacement. The printing chamber 2 can be opened from the front. This design enables the operator to easily remove the old mask plate and quickly install a new one when it is necessary to replace the mask plate for printing different patterns, thus improving work efficiency. The entire replacement process is simple and fast, and at the same time, the accuracy of the mask plate installation can be ensured.

[0040] When the charged functional material particles pass through the mask plate under the action of the electric field, in the conductive area, due to the repulsive force of the electric field, the particles are bounced off by the force opposite to the direction of the electric field and avoid deposition in this area; in the dielectric area, the electric field can penetrate the dielectric material and act on the particles, causing the particles to move towards the flexible substrate 1 and deposit under the combined action of the electric field force and the adsorption force of the flexible substrate 1, thus forming a patterned structure corresponding to the pattern of the mask plate. By precisely designing the shape, size, and distribution of the conductive area and the dielectric area on the mask plate, rapid printing of various complex patterns can be achieved.

[0041] The adsorption force of the flexible substrate 1 is mainly due to the electrostatic interaction between the surface of the flexible substrate 1 and the charged functional material particles. Based on the van der Waals force, that is, the short-range force between the particles and the surface molecules of the flexible substrate 1, the particles are embedded in the tiny depressions or pores on the surface of the flexible substrate 1.

[0042] The pattern information of the mask plate is connected to the printing control system. The control system automatically adjusts the electric field parameters (such as electric field strength, distribution, etc.) of the printing chamber 2, as well as the speed and position parameters of the driving roller 61 according to the pattern of the mask plate, ensuring that the entire system can work in coordination during the printing of different patterns to achieve efficient and accurate patterned printing. At the same time, the control system can also monitor the usage times and status of the mask plate, reminding the operator to replace or maintain the mask plate in a timely manner to ensure the printing quality.

[0043] Traditional mask plates usually only play a simple role of graphic occlusion during the printing process. The mask plate in the present invention combines a conductive region and a dielectric region, and uses an electric field to control the deposition behavior of functional material particles, achieving high-precision patterning printing. Its innovation lies in preventing the deposition of functional material particles in unwanted areas through an electric field repulsion and penetration mechanism, and at the same time improving production efficiency and printing accuracy through a quick-change design and pattern customization.

[0044] IV. Determine the tension range of the flexible substrate 1.

[0045] A sensor for monitoring its tension is provided on the transmission path of the flexible substrate 1, and the tension range of the flexible substrate 1 is 70 - 175 N.

[0046] The experimental process is as follows:

[0047] Start the printing device to ensure its normal operation. Set the initial tension range to 50 - 200 N, and gradually adjust the speed and torque of the motor 5. Adjust the tension, record the printing effect and the transmission stability of the flexible substrate 1 at different tensions. Observe the resolution of the printed samples using a microscope, and analyze the influence of tension on printing accuracy and the stability of the flexible substrate 1. Through data analysis, determine the optimal tension range to be 70 - 175 N to ensure clear printing and stable substrate transmission.

[0048] The experimental data is shown in the following table.

[0049]

[0050]

[0051] V. Determine the voltage range in the printing chamber 2.

[0052] In order to enable the functional material particles to be fully charged without causing discharge breakdown, therefore, it is necessary to determine the voltage range in the printing chamber 2.

[0053] The voltage range is mainly determined through theoretical calculations. The calculation process is as follows:

[0054] S11. According to Coulomb's law The charge on the area ΔS is obtained as Analyze the force on the functional material, that is, when the functional material particles are closer to the surface of the photosensitive drum, the electrostatic attraction is greater;

[0055] where q 1 q 2 represents the product of the mutual force between two stationary point charges and their electric charges, r represents the distance of the functional material from the electrode, Q represents the total charge on the area S, and σ represents the surface charge density;

[0056] S12. Calculate the electric field strength generated by an infinitely long charged cylindrical photoreceptor drum according to Gauss's theorem.

[0057]

[0058] Among them, E represents the electric field strength, λ represents the charge per unit length, σ represents the surface charge density, and r represents the distance from the observation point to the axis of the cylinder.

[0059] S13. Obtain the voltage range according to V = E·d.

[0060] Among them, V represents the voltage, E represents the electric field strength, and d represents the distance from the bottom of the printing chamber 2 to the flexible substrate 1.

[0061] Specifically, it is known that the charge carried by the functional material particles F = Eq.

[0062] Assume:

[0063] λ = 1×10 -6 C / m.

[0064] r = 0.05m.

[0065] q = 1×10 -10 C.

[0066] m = 1×10 -12 kg.

[0067] σ = 8.85×10 -12 C / m 2 .

[0068] Among them, F represents the electric field force, E represents the electric field, q represents the charge carried by the functional material particles, λ represents the charge per unit length, r represents the distance from the functional material particles to the electrode 3, σ is the surface charge density, and m represents the mass of the functional material particles.

[0069] Then

[0070]

[0071] According to V = E·d, the voltage is about 18 KV.

[0072] After calculation, the voltages of each functional material are as follows:

[0073] Iron powder Carbon powder Nickel powder Graphene 18.96 KV 21.68 KV 20.36 KV 20.93 KV

[0074] Furthermore, the voltage range is 18 - 22 KV, and the preferred voltage range is 21 - 22 KV to ensure that the functional material particles have sufficient driving force in the electric field to achieve effective deposition.

[0075] Further, the preparatory work before determining the voltage range includes the following steps:

[0076] First, assemble the roller shaft 6. Precisely install the driving roller 61 and the guide roller 62 on the fixing frame 7 according to the designed positions, and use high-precision bearings to ensure that the roller shaft 6 rotates flexibly and the coaxiality meets the requirements. Then install the printing chamber 2, tightly fix it on the fixing frame 7 at the corresponding position of the transmission path of the roller shaft 6, ensure that the gap between it and the roller shaft 6 is uniform, and ensure that the flexible substrate 1 can smoothly pass through the printing chamber 2 for printing. Next, install the motor 5, install the motor 5 on the mounting bracket 8 and accurately connect it to the driving roller 61, and ensure that the connecting wires are firm and the signal transmission is stable. Finally, install the sensor, install it at the key position of the transmission path of the flexible substrate 1 to monitor the tension of the flexible substrate 1 and adjust it in real time.

[0077] Second, use professional motor debugging software to connect to the motor control port and gradually adjust parameters such as the rotation speed, rotation direction, and torque of the motor 5. In the no-load state, test the start-up, acceleration, deceleration, and stop performance of the motor 5, observe whether the motor 5 runs smoothly, and check for any abnormal vibration and noise. Then load the simulated material resistance, adjust the output torque of the motor 5 according to actual requirements to ensure that the flexible substrate 1 can be stably transmitted at the set speed, and at the same time, monitor the operating state of the motor 5 in real time through the feedback signal, optimize the control algorithm, and improve the control accuracy and response speed of the motor 5.

[0078] Third, by adjusting the braking force of the braking device and combining the feedback data of the tension sensor, adjust the parameters of the tension control system. Conduct tests under different materials and different printing speeds, and obtain that the appropriate tension range is 70 - 175 N. Observe the tension change of the flexible substrate 1 during the transmission process to ensure that the tension always remains within the appropriate range and avoid the phenomenon of the flexible substrate 1 being loose or overstretched. The optimized braking device should be able to quickly respond to the change of the tension of the flexible substrate 1 and automatically adjust the braking force to ensure the stable operation of the system.

[0079] Further, while determining the voltage range, it is also necessary to determine the electrode height parameter and the printing speed parameter. The electrode height parameter is determined by combining the simulation results of the electric field distribution with the actual structure of the printing device. By designing conductive and non-conductive regions on the flexible substrate 1, the particles are ejected in the conductive region and deposited in the non-conductive region, so as to ensure that the electric field can effectively act on the target region at the specified height and achieve precise deposition. The electrode height parameter in this embodiment is 10 cm from the flexible substrate. The printing speed parameter comprehensively considers the adsorption characteristics of the material and the production efficiency requirements. It is necessary to ensure that the functional material has enough time to adsorb on the flexible substrate 1 under the action of the electric field and meet the requirements of a certain production scale. The printing speed parameter in this embodiment is 5 mm / s.

[0080] The experimental data of the electrode height parameter are as follows:

[0081]

[0082]

[0083] VI. Observe the quality of the printed flexible substrate 1.

[0084] Use a microscope to observe the resolution of the printed sample, and analyze the reasons for the samples that do not meet the standards, including the following steps:

[0085] First, in the single-print experiment, use a high-precision microscope (such as an optical microscope or an electron microscope) to measure the resolution of the printed sample, and observe the clarity of the lines, the neatness of the edges, and the integrity of the pattern. For the graphene attachment uniformity, conduct microscopic observation through a scanning electron microscope (SEM) or an atomic force microscope (AFM), and analyze the distribution of graphene particles on the surface of the PET film, such as whether there are agglomerated or sparse regions. At the same time, record the detailed parameters and results of each experiment, and establish an experimental database.

[0086] Second, when it is detected that the resolution does not meet the standard of 30mm×30mm or there are printing defects, analyze the possible reasons based on the experimental data. If it is an electrode voltage problem, gradually adjust the voltage magnitude and observe the change in the printing effect; if it is affected by the moving speed of the flexible substrate 1, increase or decrease the speed at a certain step size and re-conduct the printing test. After each parameter adjustment, repeat the above detection and analysis process, and compare the new results with the previous results. Through continuous iterative optimization, gradually find the best parameter combination to make the printing resolution meet the preset requirements, and ensure that the graphene is evenly attached, the edges are clear, and high-quality electrostatic printing is achieved.

[0087] The following is the experimental data for graphene particles to determine the best parameters:

[0088]

[0089]

[0090] It can be obtained from the above table that the parameters in the resolution of Experiment 3 are the best parameter combination, that is, the voltage is 20.95 KV, the speed of the flexible substrate is 5 mm / s, and it is 30mm×30mm.

[0091] The beneficial effects of this embodiment are as follows:

[0092] (1) High-precision printing can improve the performance of the sensor.

[0093] When traditional wet printing is used in advanced sensor manufacturing, problems such as poor precision and ink rheology lead to distortion of the graphic line width. For example, the line width error of the flexible sensor electrode is large, affecting signal transmission; the pattern of the humidity sensor is inaccurate, resulting in uneven distribution of the sensitive material and reducing performance. The roll-to-roll electrostatic printing of the present invention adjusts the electric field parameters to achieve micron-level precision (the line width error is within ±5 microns in the experiment). The corona-assisted electrostatic printing chamber acts on the functional material particles and the roll-to-roll driving and transmission method can ensure the stable transmission of the flexible substrate 1, and establish a precise micro-nano structure for the sensor. For example, the precision of the flexible sensor is improved, and the signal transmission loss is reduced by 20%; the response of the humidity sensor is 5 milliseconds faster, improving the sensitivity and accuracy.

[0094] The micron-level data of the printed electronic device graphics is shown in the following table:

[0095]

[0096] Note: The printed graphics in the experiment are HIT (mask pattern, abbreviation of Harbin Institute of Technology). This technology can ensure that the line width error of the graphics is controlled within the range of ±5 microns, meeting the micron-level precision requirements.

[0097] The comparison of the parameters of the flexible sensor and the original sensor is shown in the following table:

[0098]

[0099]

[0100] (2) The absence of an adhesive can enhance the sensor characteristics.

[0101] Traditional printing uses adhesives, which will reduce the functions of some devices. For example, it will reduce the performance of some sensors. For example, the measurement error of the flexible temperature sensor is large, and the signal conversion efficiency of the humidity sensor is low. The present invention uses adhesive-free printing, and the characteristics of the functional materials can be fully exerted. The sensitivity of the flexible temperature sensor is increased by 15%. For the humidity sensor, due to the direct contact of the material with the environment, the response speed is accelerated and the accuracy is increased by 23%, broadening the application scenarios.

[0102] The comparison of the parameters of the humidity sensor and the original sensor is shown in the following table:

[0103]

[0104] The comparison of the parameters of the flexible temperature sensor and the original sensor is shown in the following table:

[0105]

[0106]

[0107] (3) High efficiency and low cost boost the sensor industry.

[0108] 1. Improve production efficiency.

[0109] Traditional printing processes are complex and time-consuming, resulting in low production efficiency in manufacturing flexible sensors and difficulty in meeting market demands. The roll-to-roll electrostatic printing of the present invention is continuous, fast, and does not require drying, with the speed increased by about 3 times. The material supply and transmission cooperate with the process and system in a coordinated manner. For example, the motor 5 controls the roller speed to ensure accuracy, reducing the preparation time of flexible sensors and promoting their industrialization to meet market demands.

[0110] 2. Reduce production costs.

[0111] Traditional printing is costly due to the need for adhesives, etc., and also has the disadvantages of material waste and long time. The present invention does not require adhesives, saving material costs, reducing waste, shortening production time, and reducing costs by about 10%. After the cost reduction of humidity sensors, they are more likely to be popularized, improving the resource utilization efficiency.

[0112] 3. Achieve multi-functional integration.

[0113] Traditional printing technologies are difficult to achieve precise printing of multi-functional materials on the same device. The present invention can achieve precise deposition of various functional materials by precisely regulating conditions. For example, the multi-functional integration of flexible sensors, the improvement of the performance of humidity sensors, etc. With the help of CEP (Corona Enabled Electrostatic Printing) technology, the control of materials is more precise.

[0114] To achieve the precise deposition of various functional materials, mainly through precise electric field regulation, different functional materials can be deposited in different regions, thus forming complex functional patterns and structures to meet the requirements of different electronic devices. The various functional materials include: graphene, carbon powder, nickel powder, iron powder, polymer materials, etc. Its working principle: First, the functional material particles are charged by the electric field. The charged particles are guided to the designated deposition area by the force of the electric field (electrostatic force). Specifically, the electric field adjusts the intensity according to the requirements of different regions (such as conductive regions and non-conductive regions), thereby controlling the deposition process of different materials. The movement trajectories and deposition speeds of different materials in the electric field are different. Therefore, various materials can be precisely distributed to specific positions on the flexible substrate 1 according to the electric field intensity and distribution.

[0115] (4) Electrostatic patterning optimizes sensor manufacturing.

[0116] 1. Prolong the life of the mask plate and facilitate printing.

[0117] Traditional mask plates need to be in contact with ink, which makes printing prone to contamination and requires frequent plate changes, affecting the accuracy of sensors. Especially when producing flexible sensors, it may reduce product performance. Flexible sensors, due to their flexibility, thinness, comfort, and high responsiveness, are widely used in fields such as wearable devices, smart textiles, medical health, and environmental monitoring, becoming an important part of modern technology and driving the improvement of quality of life, health monitoring, and human-computer interaction. The flexible temperature sensors and humidity sensors produced by the present invention prevent particle deposition through an innovative mask plate design, ensuring product quality and accuracy. This design simplifies the production process, reduces manual intervention, lowers manufacturing difficulty, and improves production efficiency and product stability.

[0118] 2. Expand the space for personalized design.

[0119] Traditional printing is difficult to achieve personalized customization of advanced sensors. The electrostatic adsorption patterning printing of the present invention can achieve the printing of high-precision complex patterns. That is, through the precise regulation of the electric field and the pattern design of the mask plate, different functional materials can be deposited in specific areas, thereby precisely realizing the printing of complex patterns. At the same time, it can achieve on-demand customization of flexible sensors in wearable devices and environment-based customization of humidity sensors. By relying on the mask plate, particles can be deposited in different areas, promoting the personalized development of sensors.

[0120] The working principle of this embodiment is as follows:

[0121] In the feeding stage, the motor 5 is started, and the motor 5 controls the driving roller 61 to rotate at a low speed. The tension sensor and the braking device keep the flexible substrate 1 under low tension. The flexible substrate 1 enters the printing chamber 2 under the guidance of multiple roller shafts 6. During the printing process, the motor 3 adjusts the rotation speed of the driving roller 61 according to the preset speed. At the same time, the electrode 3 in the printing chamber 2 is started to generate an electric field, so that the graphene particles in the feeder 4 can pass through the dielectric region of the mask plate arranged above it and be deposited on the non-conductive region of the flexible substrate 1, that is, the bottom of the flexible substrate 1, realizing the electrostatic adsorption printing of functional materials. Under the action of the tension sensor and the braking device, the tension is monitored and maintained stably in real time. In the discharging stage, the motor 5 gradually reduces the rotation speed of the driving roller 61 until the flexible substrate 1 is completely unloaded, and the entire system stops working.

[0122] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "left", "right", "up", "down", "top", "bottom", "front", "rear", "inner", "outer", "back", "middle", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present invention.

[0123] However, the above are only specific embodiments of the present invention, and the scope of implementation of the present invention cannot be limited thereby. Therefore, the replacement of equivalent components or equivalent changes and modifications made according to the scope of protection of the present invention shall still fall within the scope covered by the claims of the present invention.

Claims

1. A roll-to-roll electrostatic printing device, characterized in that: It comprises a power component and a printing component with a mask plate inside, the power component drives a rolled flexible substrate (1) to pass through the printing component for electrostatic printing, and functional materials are deposited on the flexible substrate (1) by penetrating the dielectric area of ​​the mask plate using the electric field generated in the printing component.

2. The roll-to-roll electrostatic printing device according to claim 1, characterized in that: The mask plate includes a conductive area and a dielectric area, the conductive area repels the electric field, and the dielectric area adopts a pre-patterning design and is filled with an insulating material.

3. The roll-to-roll electrostatic printing device according to claim 1, characterized in that: The printing component also includes a printing chamber (2), an electrode (3) and a feeder (4) for placing the functional material, wherein the electrode (3) is suspended in the printing chamber (2) and is located above the flexible substrate (1), the feeder (4) has an open top and is arranged at the bottom of the printing chamber (2), and the mask plate is arranged between the flexible substrate (1) and the feeder (4).

4. The roll-to-roll electrostatic printing device according to claim 3, characterized in that: The power component comprises a motor (5) and a plurality of rollers (6), wherein the rollers (6) are mounted on a fixed frame (7), the motor (5) is drivingly connected to one or more of the rollers (6), the flexible substrate (1) is sequentially wound around the plurality of rollers (6), and the printing chamber (2) is arranged on a transmission path of the flexible substrate (1).

5. The roll-to-roll electrostatic printing device according to claim 1, characterized in that: The functional materials include graphene, carbon powder, nickel powder, iron powder and polymer materials.

6. The roll-to-roll electrostatic printing device according to claim 1, characterized in that: A sensor for monitoring the tension of the flexible substrate (1) is arranged on the transmission path of the flexible substrate (1), and the tension range of the flexible substrate (1) is 70-175N.

7. The roll-to-roll electrostatic printing device according to claim 3, characterized in that: A door body is installed on the front of the printing room (2), and the door body is magnetically attracted to the printing room (2).

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