Electrostatic-induction-based dry-powder automatic pattern filling apparatus and method, and applications thereof
Patent Information
- Application Number
- PCT/CN2025/085965
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-03-28
- Publication Date
- 2026-10-01
Smart Images
Figure CN2025085965_01102026_PF_FP_ABST
Abstract
Description
An electrostatically induced dry powder automatic pattern filling device, method and application Technical Field
[0001] This invention relates to the field of electronic printing technology, and in particular to an electrostatically induced dry powder automatic graphic filling device, method and application. Background Technology
[0002] Compared to traditional silicon-based processes, electronic printing technology offers advantages such as higher speed, lower cost, larger size, and greater flexibility, leading to its increasingly widespread application in the integrated circuit field. As the requirements for device miniaturization, multifunctionality, and high performance continue to increase, higher demands are being placed on the precision, performance, and efficiency of electronic printing technology. The precision and quality of the printed pattern directly determine the size and performance of the device, while the efficiency and speed of the printing process directly impact the product's cost and application scope.
[0003] To improve printing efficiency, researchers developed roll-to-roll (R2R) printing technology early on. R2R is a technique that continuously processes flexible substrates in roll-to-roll fashion, offering significant efficiency gains due to its continuous processing capabilities; printing speeds can exceed 100 meters per minute. Screen printing, flexographic printing, and gravure printing are all compatible with this R2R process. Therefore, compared to inkjet printing, these technologies offer higher printing efficiency and lower costs, leading to their widespread application in flexible printed electronics. For example, R2R printing is used to prepare large-area, conductive flexible graphene films.
[0004] Most roll-to-roll printing technologies require alignment systems to ensure that the printed pattern is precisely aligned with the target position on the substrate during continuous printing, thereby guaranteeing print quality and product performance. For example, screen printing requires interlayer alignment systems to achieve high-precision printing. Current alignment systems utilize optical detection devices (such as CCD cameras) to capture positioning marks and printed patterns on the substrate, analyze positional deviations of the marks using image processing algorithms, and then perform fine-tuning through mechanical structures. Current technologies focus on improving detection accuracy, efficiency, and automation; however, the alignment step itself increases the complexity of the entire printing process and raises printing costs.
[0005] Currently, most printing technologies require combining functional materials with organic binders to create electronic pastes or inks to achieve material transfer and patterning. The rheological properties and coffee ring effect of pastes and inks reduce printing quality and precision, while the ink preparation and drying processes also decrease printing efficiency. Furthermore, the coating effect of binders on functional materials results in lower sensitivity or conductivity of printed structures in existing technologies. Many technologies are currently working to increase the proportion of functional materials in pastes and inks, or to reduce the impact of binders in the paste on the performance of the fabricated devices. However, the presence of binders still limits the functional properties of the functional materials themselves, fundamentally restricting the miniaturization and integration of printed devices.
[0006] In summary, considering the current application of new technologies, the operation process of the widely used roll-to-roll printing technology is relatively complex, generally requiring processes such as ink preparation and interlayer alignment. Therefore, further improvements to electronic printing technology are needed. Summary of the Invention
[0007] The purpose of this invention is to overcome the shortcomings of the above-mentioned technologies and provide an electrostatically induced assisted dry powder automatic graphic filling device, method and application that has low implementation cost, balances printing efficiency and accuracy, and does not require alignment.
[0008] Therefore, this invention provides an electrostatically induced dry powder automatic pattern filling device, mainly comprising an upper substrate and a lower substrate, one of which is the substrate to be printed; an electrode is provided above the upper substrate for corona discharge; a conductive pattern is attached, deposited, and coated on the substrate to be printed. The area to be printed of the conductive pattern is an insulating structure, and the adjacent areas of the area to be printed are conductive structures; wherein the insulating area occupies most of the area, and the conductive area is often deposited on the surface of the insulating area in a patterned form.
[0009] Preferably, the apparatus further includes a feeding system, which is a powder conveying assembly for continuously or intermittently conveying the powder to be printed to the substrate.
[0010] Preferably, current technology can already achieve printing on most conductive materials below the millimeter scale, including metal powder materials such as iron, copper, silver, nickel, or tin; conductive polymer materials such as PEDOT:PSS and polyaniline; and other functional materials with certain conductivity such as carbon nanotubes, indium tin oxide, and graphene. Printing on other functional micro / nano powders with poor conductivity can also achieve good results by adjusting the applied electric field strength and particle size, including semiconductor particles such as zinc oxide, silicon dioxide, and silicon carbide.
[0011] On the other hand, the present invention also provides an electrostatically induced dry powder automatic graphic filling method, the printing steps mainly including:
[0012] S1. Print conductive patterns on the substrate to be printed;
[0013] S2. The electrode is activated to perform corona discharge, forming an electric field between the upper and lower substrates. The powder to be printed is then conveyed between the upper and lower substrates through the feeding system. Under the action of the electric field, the powder automatically covers the insulating area of the substrate to be printed and bounces off in the conductive area, thus completing the pattern printing.
[0014] Preferably, after pattern printing, some particles need to be vibrated to remove dust from the substrate surface. The printed substrate is then transported to a low-temperature micro-nano interconnect device for further processing to reinforce the printed pattern.
[0015] Preferably, the particle size of the powder to be printed is 1-100 micrometers, and the corona discharge voltage range is 9-20kV.
[0016] Preferably, the width ratio of the conductive region to the insulating region is 0.75 to 10.
[0017] Preferably, the vibration treatment frequency is 50-60Hz, the amplitude is 4-5mm, and the time is 40-60s.
[0018] The beneficial effects of this invention are:
[0019] 1) Automatic patterning: In the enhanced electric field generated by corona discharge, the rapidly reciprocating powder to be printed will automatically bounce off the conductive area in the pattern and only stay in the non-conductive area, thus automatically completing the patterning. This avoids the wear and cleaning of traditional electronic printing templates, thereby improving printing accuracy, speeding up printing, and reducing the use of organic solvents.
[0020] 2) No need to prepare printing ink: No organic binder is needed as a carrier to achieve material transfer and patterning, avoiding the high temperature and long drying process and reducing nozzle clogging problems; it broadens the selection range of printing powder materials and substrates; it avoids the coating effect of binder on functional materials and improves device sensitivity; there is no coffee ring effect, which can further improve printing accuracy.
[0021] 3) Non-contact: The dynamic and controllable enhanced electric field is generated by non-contact corona discharge, which increases the degree of freedom of the printing system; the dynamic electric field that changes with the printing process has an automatic screening effect on material size, which helps to improve printing accuracy and control printing thickness.
[0022] 4) Easy roll-to-roll printing: Since the roll-to-roll processing technology of corona discharge for thin films has been maturely applied in the industry, reusable movable templates can be used to replace substrate patterning to directly realize roll-to-roll printing, thereby improving printing speed, reducing production costs, and rapidly producing large-size printed electronics.
[0023] 5) Eliminates alignment process: Because it can automatically fill and align the insulating area, it saves the process of aligning the subsequent layer with the preceding layer in the fabrication of printed electronics, saving production time, improving production accuracy and reducing production costs. Attached Figure Description
[0024] Figure 1 is a schematic diagram illustrating the particle motion principle of the present invention;
[0025] Figure 2 is a schematic diagram illustrating the charge transfer process of the present invention;
[0026] Figure 3 is a schematic diagram of the preparation of the conductive structure in a specific embodiment of the present invention;
[0027] Figure 4 is a schematic diagram of the graphic printing behavior in a specific embodiment of the present invention;
[0028] Figure 5 is a schematic diagram of the automatic graphical behavior principle in a specific embodiment of the present invention;
[0029] Figure 6 is a schematic diagram of the method flow of the present invention;
[0030] Figure 7 is a schematic diagram illustrating the study of process parameters printing voltage and deposition width in this invention.
[0031] Figure 8 is a schematic diagram of the curve analysis of printing voltage as a process parameter according to the present invention;
[0032] Figure 9 is a schematic diagram illustrating the research and analysis of particle size as a process parameter in this invention.
[0033] Figure 10 is a schematic diagram of the research and analysis of particle types in process parameters according to the present invention.
[0034] Figure 11 is an analysis diagram of particle motion behavior after high-speed camera shooting in this invention;
[0035] Figure 12 is a simulation analysis diagram of the COMSOL software simulation analysis in this invention;
[0036] Figure 13 is an analysis diagram of the particle charge transfer mechanism in this invention;
[0037] Figure 14 is a diagram analyzing the range of materials applicable to the printing technology in this invention.
[0038] Figure 15 is a device application diagram of the printing technology in this invention.
[0039] The markings in the diagram are: 1. Upper substrate, 2. Lower substrate, 3. Layer to be printed, 4. Printed pattern, 5. Powder particles, 6. Electrode, 7. Design pattern, 10. Hollowed-out pattern. Detailed Implementation
[0040] The present invention will be further described below with reference to the accompanying drawings and specific embodiments to aid in understanding its content. Unless otherwise specified, the methods used in this invention are conventional methods; the raw materials and apparatus used, unless otherwise specified, are conventional commercially available products.
[0041] This invention provides an electrostatically induced dry powder automatic pattern filling device, mainly comprising an upper substrate 1 and a lower substrate 2. A needle-shaped electrode 6 is provided above the upper substrate 1 for corona discharge, creating a controllable dynamically enhanced electric field between the two substrates. When micro / nano powder is added to the two substrates, as shown in Figure 1, the powder moves rapidly back and forth between the two substrates due to the electric field force. Taking the movement of a single powder particle 5 as an example, the particle is polarized and subjected to the electric field force. This electric field force overcomes gravity, causing the particle to move upwards along the electric field lines and then collide with the charged upper substrate. If both the upper substrate and the printing material are conductive, charge transfer occurs between the polarized particle and the substrate, resulting in repulsion as both carry the same charge. Simultaneously, momentum conversion occurs during the collision, resulting in a bounce effect. The particle then reaches the lower substrate. If it is a conductive area, the above process repeats; if it is a non-conductive area, due to opposite polarities, it remains in the insulating area. Furthermore, observation shows that it moves rapidly back and forth at a speed of 1–5 m / s (high-speed camera). It should be noted that Figure 1 is only a simplified model for illustration; the actual motion is more complex due to collisions between powder particles. Furthermore, to achieve the above-mentioned effects in this embodiment, the printing powder is preferably a metallic powder material such as iron, copper, silver, nickel, or tin; conductive polymer materials such as PEDOT:PSS, polyaniline, etc.; other functional materials with certain conductivity such as carbon nanotubes, indium tin oxide, graphene, etc.; and semiconductor materials including zinc oxide, silicon dioxide particles, silicon carbide, etc., which can be selected in one or more combinations. Currently, printing of powder particles such as poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT:PSS), graphene, carbon nanotubes, silicon dioxide, graphene oxide, iron, copper, silicon carbide, boron carbide, and tin has been achieved.
[0042] The overall process flow is as follows. This embodiment focuses on combining roll-to-roll printing technology because roll-to-roll printing technology is relatively mature, equipment manufacturing technology is relatively complete, and the overall technology is easy to apply in practice. First, conductive patterns need to be made on the substrate to be printed using methods such as screen printing. Screen printing is also suitable for roll-to-roll processes, so it also has high printing efficiency. Referring to Figure 3, in this embodiment, the layer to be printed 3 is selected as the printing substrate for the pattern to be printed. It is attached to the surface of the upper substrate 1, and a screen printing stencil 9 is added accordingly. The surface of the stencil 9 is processed with a cutout pattern 10 corresponding to the printed pattern. The pattern 10 is transferred to the layer to be printed 3 by screen printing to form the printed pattern 4. The conductive pattern on the substrate is then completed.
[0043] The next step is electrostatic induction dry powder automatic patterning filling. As shown in Figure 5, the upper substrate 1 is used as the printing layer for patterning. The printing layer 3 can be directly attached to the conductive upper substrate 1, or an insulating upper substrate 1 can be used as the printing layer 3. Specifically, conductive and insulating regions are separately provided on the upper substrate 1. Referring to the example process in Figures a-c of Figure 2, when the powder particles reciprocate between the upper substrate 1 and the lower substrate 2 for a period of time, they will come into contact with the insulating region. Since the charge does not transfer or only transfers slightly, the particles will not bounce away again. Thus, the powder continuously stays in the insulating region, achieving the effect of automatic pattern coverage. The insulating region corresponds to the printed pattern, thereby realizing automatic patterning.
[0044] Similarly, the lower substrate 2 can also be used to attach the layer 3 to be printed. Under the action of the electric field, the particles will also be deposited in the insulating area after reciprocating between the upper and lower substrates, and bounce off in the conductive area to form the corresponding printed pattern (Figure 4).
[0045] After printing, some highly viscous particles require vibration treatment to remove dust from the substrate surface. Preferably, depending on the characteristics of the selected powder, the overall electrostatic printing device also includes a low-temperature micro-nano interconnect device located downstream of the printing side. The printed film is conveyed to the low-temperature micro-nano interconnect device after printing (automatic patterning), and the printed pattern can be reinforced through a series of processes.
[0046] During the process, powder conveying components can be set on the sides of the upper and lower substrates. Specifically, a conveyor belt can be used to directly transport the particles to the area to be printed, or a powder spray gun or micro nozzle can be used to continuously transport the powder to be printed between the upper and lower substrates under the action of airflow.
[0047] On the other hand, in conjunction with Figure 6, the present invention also provides an electrostatically induced dry powder automatic graphic filling method based on the above-mentioned device, the main printing steps of which include:
[0048] S1. Print conductive patterns on the layer to be printed 3 using screen printing or other methods, and then attach the layer to be printed 3 to the surface of the upper or lower substrate.
[0049] S2. The starting electrode 6 performs corona discharge, forming an electric field between the upper and lower substrates. The powder is then transported between the upper and lower substrates via the powder delivery assembly. Under the influence of the electric field, the powder automatically covers the insulating area and bounces off the conductive area, completing the pattern printing.
[0050] S3. Some particles require vibration treatment to remove surface dust from the substrate. The printed substrate can then be transported to a low-temperature micro / nano interconnect device, where a series of processes can be used to reinforce the printed pattern.
[0051] Printing process conditions:
[0052] In this invention, the printing process conditions have a significant impact on the printing effect of powder materials. These conditions include: printing voltage, powder particle size, the width ratio of the conductive to the insulating region, and the properties of the particles themselves. This invention uses the deposition ratio on the non-conductive area (R) as the basis for determining the printing effect. d The contamination ratio on the conductive area (electrode area) and the proportion of contamination in the conductive area (R). c As a preliminary indicator for measuring depositional efficiency, r = R d -kR c (k is a constant) is used as a criterion to evaluate the quality of the final patterned deposition effect of the particles. The larger the r is, the better the deposition effect of the particles and the stronger the pattern recognition ability. The following are the specific analysis results of the influence of process printing conditions on printing effect.
[0053] The electric field strength has the most direct impact on powder printing results. The magnitude of the electric field strength affects the polarization intensity of the powder particles, thus influencing the particle deposition distribution. Many factors influence the printing electric field strength, including the distance between the corona discharge needles, the number and arrangement of the needles, and the voltage applied to the needles. Among these, the applied voltage has the most significant impact on particle deposition. As shown in Figures 7 and 8, with the distance between the discharge needle and the upper substrate set to 1.5 cm, the distance between the upper and lower substrates set to 1 cm, and the deposition area being a patterned polystyrene / gold region, the deposition of 10-50 μm PEDOT:PSS particles and 1-10 μm PEDOT:PSS particles under different printing voltages was investigated. It was found that R... d It increases with increasing printing voltage, while R cThe voltage will increase, decrease, and then increase again as the printing voltage increases. This is because as the printing voltage increases, the electric field strength in the printing area gradually increases, and the number of polarized particles also gradually increases, thereby increasing the probability of particle collisions in the conductive area, which in turn leads to R... c Increase. However, as the voltage further increases, the electrostatic force on the particles gradually increases, and the electrostatic repulsion in the conductive region also increases. Therefore, R in this stage... c There was a slight decline. However, with further increases in printing voltage, the increased kinetic energy of particles impacting the substrate enhances particle adhesion, thus R... c This is further increased. Therefore, the optimal deposition effect can be achieved by adjusting the printing voltage of the particles. For 1-50 micrometer PEDOT:PSS, the printing voltage range is 9-20 kV.
[0054] The width ratio of the conductive to insulating regions also affects the distribution of the electric field during printing, potentially influencing the final printing result. Therefore, experiments were conducted to test the printing effect within a width ratio of 0.75 to 10 for the conductive to insulating regions (Figures 7 and 9). The particles could achieve patterned deposition within these regions, indicating that this printing technology has a wide range of applications. Furthermore, the experiments revealed that the width ratio of the conductive to insulating regions has a more significant impact on the printing effect at lower printing voltages, while its influence decreases considerably at higher printing voltages.
[0055] The properties of the particles also have a significant impact on the printing effect. First, the particle size affects the stress on the particles during the printing process (including electrostatic force, adhesive force, and gravity), which in turn affects the final deposition effect. Figure 9 shows the deposition behavior of PEDOT:PSS particles with three different diameter ranges of 1-10μm, 10-50μm, and 50-100μm under the optimal printing voltage. Analysis of the data shows that the R0 of the particles with the three diameters... d Both can reach 70% to 80%, while R c However, there are significant differences, with PEDOT:PSS particles with diameters of 10-50 μm showing varying R values. c The smallest particle size yields the best printing results. Too small a particle diameter increases adhesion between the particles and the substrate, while too large a particle diameter may result in some deposition at the interface between conductive and insulating areas, affecting the deposition effect. The conductivity of the particles also affects the printing process and printing results; the higher the conductivity of the particles, the better the printing effect. c The smaller the value, the larger the value of r. Experiments were conducted to test the printing effects of various particles, including graphene oxide, carbon nanotubes, silicon dioxide, nickel powder, and tin powder (Figure 10, Table 1). Analysis revealed that R... d All can reach over 55%, R cFor printing of graphics, the following parameters are all applicable: no more than 11%, k value is 5, and r value is greater than zero. The printing voltage range is 9kV to 20kV.
[0056] Finally, the vibration treatment process was studied, and it was found that when the vibration frequency was 50-60Hz, the amplitude was 4-5mm, and the time was 40-60s, the floating dust on the substrate surface could be effectively removed. At the same time, the proportion of particles deposited in the conductive area also decreased, and the r value increased slightly.
[0057] Printing principle and mechanism:
[0058] To understand the mechanism of AEP (Alternating Electrostatic Effort), the printing behavior of a single aluminum ball (1.6 mm in diameter) was compared on upper substrates made of polystyrene (PS), silicon (Si), and stainless steel (SS), respectively. The motion of the aluminum ball was captured using a high-speed camera, and its changes in the z-direction / vertical position (measured from the distance to the lower substrate) were tracked using MATLAB. The displacement, velocity, and acceleration of the particles were analyzed, and the corresponding motion curves were plotted (Figure 11). Analysis revealed that the aluminum ball directly adheres to the polystyrene substrate; on the silicon and stainless steel substrates, the aluminum particles circulate back and forth between the upper and lower substrates. On the silicon substrate, the velocity and acceleration reached 0.8 m / s and 28.7 m / s², respectively. On the stainless steel substrate, due to its better conductivity, the particle velocity increased to 1.0 m / s, and the acceleration reached 29.1 m / s². The adhesion of the aluminum ball to the polystyrene substrate indicates that the direction of the electrostatic force remains unchanged, while the bounce-off of the aluminum ball on the silicon and stainless steel substrates indicates that the direction of the electrostatic force changes.
[0059] To investigate the cause of the change in the direction of the electrostatic force on the particles, COMSOL was used to simulate the electric field distribution under different substrates. Figure 12 shows the two-dimensional electric field distribution, indicating that the electric field strength increases with the increase of the conductivity of the substrate. This finding can explain why the aluminum ball moves faster than the silicon substrate when the substrate is stainless steel. However, although the electric field strength is slightly weaker at the PS substrate, the direction of the electric field is consistent with that of the stainless steel and silicon substrates, indicating that the electric field strength is not the cause of the change in the direction of the electrostatic force on the particles. Therefore, it can be considered that the change in the amount of charge carried by the particles is the main reason for the change in the direction of the electrostatic force on the particles.
[0060] To perform a more in-depth quantitative analysis of charge transfer, it is necessary to calculate the charge carried by the sphere during its rising and falling phases. Therefore, we can use the printing voltage to calculate the electric field strength, according to the formula Q. m =2 / 3π 3 εr 2 E is used to calculate the charge carried by the particle. Furthermore, the difference in the normalized charge ratio before and after the collision is calculated, i.e., Ratio = Q / Q. mThe charge transfer rate for each material was obtained by multiplying the value by 100% (Figure 13a). Furthermore, additional data on velocity changes during collisions are needed to further analyze the kinematic model of the constructing particles. Specifically, the coefficient of restitution (COR) is used to characterize the inelastic collision behavior, where COR = V / V. a / V b (Figure 13b). Based on a series of principle, technology and experimental studies, the applicable scope of this technology for printable particulate materials was determined (Figure 14).
[0061] Applications of printing technology:
[0062] A three-lead multiaxial patterned sensor (i.e., strain rose) was fabricated using the automated selective deposition of functional nanoparticles. In the fabrication process, a pre-laser-cut stainless steel mask is first placed on an adhesive substrate, and the sensing pattern is formed when AEP (Automatic Ejection Process) is activated. After printing, the mask is carefully removed, resulting in an ultra-thin, flexible sensor (Figure 15). Due to the AEP mechanism, particles do not aggregate on the mask, making the printing process clean, user-friendly, and efficient. This self-cleaning property contributes to environmentally friendly, convenient, material-saving, and rapid flexible electronics printing, all of which can be achieved without adhesives. Therefore, this technology can be used to fabricate various flexible devices, including flexible pressure sensors and flexible temperature sensors. The fabricated devices exhibit high sensitivity and can be fabricated over large areas with high efficiency, showing broad application prospects.
[0063] Table 1 presents the data analysis of particle performance and printing effect tested in this invention.
[0064] Table 1
[0065] In the description of this invention, it should be understood that the terms "left", "right", "up", "down", "top", "bottom", "front", "back", "inner", "outer", "back", "middle", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0066] However, the above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made in accordance with the scope of protection of the present invention should still fall within the scope of the claims of the present invention.
Claims
1. An electrostatically induced dry powder automatic graphic filling device, characterized in that, It includes an upper substrate and a lower substrate, one of which is the substrate to be printed; an electrode is provided on the upper substrate for corona discharge; a conductive pattern is attached, deposited and coated on the substrate to be printed; The area to be printed in the conductive pattern is an insulating structure, and the adjacent area to the area to be printed is a conductive structure.
2. The electrostatically induced dry powder automatic graphic filling device according to claim 1, characterized in that, The device also includes a feeding system, which is a powder conveying assembly for continuously or intermittently conveying the powder to be printed to the substrate.
3. The electrostatically induced dry powder automatic graphic filling device according to claim 2, characterized in that, The powder to be printed includes one or more combinations of metal powder materials, conductive polymer materials, functional materials with certain conductivity, and semiconductor materials.
4. The electrostatically induced dry powder automatic graphic filling device according to claim 3, characterized in that, The metal powder material is iron, copper, silver, nickel, or tin; the conductive polymer material is PEDOT:PSS or polyaniline; the functional material with a certain conductivity is carbon nanotubes, indium tin oxide, or graphene; and the semiconductor material is zinc oxide, silicon dioxide particles, or silicon carbide.
5. A method for automatic graphic filling using electrostatically induced dry powder, characterized in that, The printing steps include: S1. Print conductive patterns on the substrate to be printed; S2. The electrode is activated to perform corona discharge, forming an electric field between the upper and lower substrates. The powder to be printed is then conveyed between the upper and lower substrates through the feeding system. Under the action of the electric field, the powder automatically covers the insulating area of the substrate to be printed and bounces off in the conductive area, thus completing the pattern printing.
6. The electrostatically induced dry powder automatic graphic filling method according to claim 5, characterized in that, After patterning and printing, some particles need to be vibrated to remove dust from the substrate surface. The printed substrate is then transported to a low-temperature micro-nano interconnect device for further processing to reinforce the printed pattern.
7. The electrostatically induced dry powder automatic graphic filling method according to claim 5, characterized in that, The powder to be printed is preferably graphene, carbon nanotubes, Ni, Sn or PEDOT:PSS, with a particle size of 1-100 micrometers and a corona discharge voltage range of 9-20kV.
8. The electrostatically induced dry powder automatic graphic filling method according to claim 5, characterized in that, The width ratio of the conductive area to the insulating area is 0.75 to 10.
9. The electrostatically induced dry powder automatic graphic filling method according to claim 6, characterized in that, The vibration treatment frequency is 50-60Hz, the amplitude is 4-5mm, and the time is 40-60s.
10. An application of an electrostatically induced dry powder automatic graphic filling method, characterized in that, Flexible devices can be fabricated, including flexible pressure sensors and flexible temperature sensors.