Electrostatic field induced microparticle patterned assembly device and preparation method thereof

Abstract

The application provides a preparation method of a device based on electrostatic field induced microparticle patterning directional assembly, comprising the following steps: preparing a pre-patterning electrode and printing or depositing the pre-patterning electrode on a substrate to obtain a pre-patterning substrate; uniformly laying microparticles on a lower substrate and placing the pre-patterning substrate between the lower substrate and an upper substrate; forming a controllable electric field between the upper substrate and the lower substrate through corona discharge, and driving the microparticles to deposit on non-conductive areas of the pre-patterning substrate by electric field force to form a patterning conductive channel corresponding to the electrode; and packaging the substrate on which the patterning directional assembly is completed. The application realizes template-free, contact-free and solvent-free patterning directional assembly of microparticles, and has the advantages of simple process, low cost, high efficiency and strong universality. The application can be used to prepare multiple devices such as photoelectric detectors, pressure sensors and flexible electronics, and has important industrial application value.

Description

Technical Field

[0001] This invention relates to the field of electronic device fabrication technology, and in particular to a device based on electrostatic field-induced microsheet patterned directional assembly and its fabrication method. Background Technology

[0002] Micronflakes, due to their high specific surface area, anisotropic photoelectric transport properties, excellent mechanical flexibility, and tunable chemical activity, have shown broad application potential in devices such as photodetectors.

[0003] Currently, the directional assembly of micron-sized wafers mainly employs techniques such as stencil methods, micro-transfer printing, and capillary self-assembly to achieve patterned arrangement on rigid or flexible substrates for the fabrication of electronic devices. These processes all have technical limitations. Stencil methods and micro-transfer printing require auxiliary consumables such as stencils and masks, which not only increases process complexity and cost but also easily leads to contamination of the micron-sized wafers and the substrate. Capillary self-assembly uses solvents to transfer micron-sized wafers, which not only damages the intrinsic physicochemical properties of the wafers but also increases subsequent processing time, prolonging the fabrication cycle and reducing production efficiency.

[0004] The existing fabrication of micron-sized sheet-oriented assembly devices still has many shortcomings, such as difficulty in achieving uniform patterning of micron-sized sheets and high control difficulty. It cannot guarantee the quality of large-area patterned assembly and mass production of devices, and it is difficult to meet the needs of high-precision, large-scale microelectronic device integration applications. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the above-mentioned technologies and provide a device for patterned and oriented assembly of microsheets based on electrostatic field-induced microsheets and its preparation method.

[0006] Therefore, the present invention provides a method for fabricating a patterned and oriented assembly device based on electrostatic field-induced microsheets, comprising the following steps:

[0007] S1. Prepare a pre-patterned electrode and print or deposit it on a substrate to obtain a pre-patterned substrate;

[0008] S2. The micron-sized sheet is evenly laid on the lower substrate, and the pre-patterned substrate is placed between the lower substrate and the upper substrate.

[0009] S3. A controllable electric field is formed between the upper and lower substrates by corona discharge. The micron sheet is driven by the electric field force to be deposited on the non-conductive area of ​​the pre-patterned substrate, forming a patterned conductive channel that precisely corresponds to the electrode.

[0010] S4. Encapsulate the substrate after completing the graphical orientation assembly.

[0011] Preferably, in step S2, the micron-sized sheets are uniformly deposited on the lower substrate by sieving or electric field-driven dispersion.

[0012] Preferably, the electric field-driven dispersion method includes the following steps:

[0013] S21. Place an insulating support frame on the lower substrate and place the messy micron flakes on the lower substrate;

[0014] S22. Place the upper substrate on top of the insulating support frame to form a closed space between it and the lower substrate;

[0015] S23. Using corona discharge, the micron sheet moves and collides rapidly in a closed space;

[0016] S24. After the pressure is stopped, the micron-sized sheets fall and are evenly dispersed on the lower substrate.

[0017] Preferably, the voltage applied for dispersing the micron-sized sheets is 5-15kV, and the time is 1-10s.

[0018] Preferably, the substrate comprises one or more of polyethylene terephthalate, polyimide, polydimethylsiloxane, nonwoven fabric, and paper, with a substrate thickness of 20-100 μm; the electrode comprises one or more of gold, silver, copper, cadmium, aluminum, indium tin oxide, and graphite, with an electrode layer thickness of 2-10 μm.

[0019] Preferably, in step S3, the voltage driving the deposition of the microsheet is 5-25kV, the distance between the discharge needle and the upper substrate is 1-10cm, the spacing between the pre-patterned substrate electrode surface and the microsheet layup on the lower substrate is 2-8cm, and the deposition time is 300ms-30s.

[0020] Preferably, in step S4, the substrate that has completed patterned orientation assembly is encapsulated with a micron film, wherein the micron film is one or more of polyethylene terephthalate, polyimide, and polydimethylsiloxane, and the film thickness is 10-20 μm; the electrode leads are led out through silver conductive paste or gold wire bonding.

[0021] Preferably, after packaging in step S4, the device also needs to undergo annealing. The specific steps are as follows:

[0022] Place the device in a glove box hot stage, heat it to 200℃-240℃, keep it at that temperature for 20-60 minutes, and then let it cool naturally to room temperature.

[0023] Preferably, after the packaging in step S4 is completed, the device also needs to undergo a water vapor capillary filling enhancement treatment. The specific steps are as follows:

[0024] Place the device in a water vapor environment with a relative humidity of 85%-97% for 12-24 hours to allow water vapor to condense capillarily in the gaps between the micron sheet and the electrode and fill the gaps.

[0025] Then, dry in a 50℃ forced-air oven for 2-10 hours or heat on an 80℃ hot table for 5-10 minutes to remove moisture.

[0026] The present invention also provides a device for electrostatic field-induced microsheet patterning orientation assembly, comprising a substrate, electrodes pre-patterned on the substrate, microsheets, and an encapsulation layer, wherein the microsheets cover the non-conductive regions of the electrodes and form electrical contacts with the electrodes.

[0027] This invention provides a device based on electrostatic field-induced patterned orientation assembly of microsheets and its fabrication method, which has the following beneficial effects:

[0028] (1) The directional self-assembly of micron-sheets does not require masks, physical contact and solvent assistance. The movement of micron-sheets can be induced by electrostatic field to selectively deposit non-conductive regions, i.e. insulating regions, on the substrate.

[0029] (2) Low cost, simple process, and high production efficiency, which is conducive to large-area assembly and industrial manufacturing. Except for the pre-patterned substrate, no pre-process or mask-assisted technology is required, and the patterned electrode is a component of the device, which effectively reduces cost consumption;

[0030] (3) It has strong controllability. By changing the voltage, the distance between the discharge needle and the upper substrate, the number and arrangement of the discharge needles, the electric field strength and its distribution between the upper and lower substrates can be controlled, thereby making the orientation assembly behavior of micron-sized sheets controllable.

[0031] (4) Achieve multifunctional integration. Through the precise deposition of micron sheets with different functions, sensors with different functions can be fabricated, such as photoelectric sensors, pressure sensors, and tactile sensors. Attached Figure Description

[0032] Figure 1 This is a schematic diagram illustrating the working principle of electrostatic field-induced patterned directional assembly of micron-sized sheets;

[0033] Figure 2 This is a diagram showing the effect of applying different voltages to a discharge needle.

[0034] Figure 3 It shows the electric field effect between the upper and lower substrates at different spacings;

[0035] Figure 4 This is a schematic diagram of the structure of a micron-scale electric field-driven dispersion device;

[0036] Figure 5 This is a diagram showing the effect of dispersing micron-sized sheets using an electric field-driven dispersion method.

[0037] Figure 6 This is a graph showing the effect of annealing on device performance;

[0038] Figure 7 This is a graph showing the effect of water vapor capillary filling enhancement treatment on device performance;

[0039] Figure 8 This is a schematic diagram of the structure of a near-infrared photodetector;

[0040] Figure 9 This is a current-voltage curve of a near-infrared photodetector under 808nm illumination;

[0041] Figure 10 This is a micrograph of the automatically assembled graphite sheet pattern with orientation in Example 1;

[0042] Figure 11 These are micrographs of the patterned oriented assembly of Bi2O2Se microsheets between electrodes with different spacings in Examples 2 and 3;

[0043] Figure 12 yes Figure 11 Enlarged image of a medium-micron sheet;

[0044] Figure 13 These are the ultraviolet-visible-near-infrared absorption spectra of the Bi2O2Se microsheets in Examples 2 and 3.

[0045] The markings in the diagram are: 1. Substrate; 2. Electrode; 3. Microsheet; 4. Microfilm; 5. Insulating support frame; 6. Upper substrate; 7. Lower substrate. Detailed Implementation

[0046] 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.

[0047] like Figures 1 to 13 As shown, this invention provides a method for fabricating a device based on electrostatically induced microsheet patterned directional assembly, comprising the following steps:

[0048] S1. Prepare a pre-patterned electrode 2 and print or deposit it on the substrate 1 to obtain a pre-patterned substrate.

[0049] Conductive electrode layers are printed or deposited on flexible or rigid substrates using processes such as screen printing, magnetron sputtering, thermal evaporation, or photolithography to form pre-patterned substrates with specific geometric patterns. The electrode patterns can be parallel electrodes, interdigitated electrodes, or other desired patterns.

[0050] The substrate 1 material includes one or more of polyethylene terephthalate (PET), polyimide (PI), polydimethylsiloxane (PDMS), nonwoven fabric, or paper, with a substrate thickness of 20-100 μm. The electrode 2 material includes one or more of gold, silver, copper, aluminum, indium tin oxide (ITO), or graphite, with an electrode layer thickness of 2-10 μm.

[0051] This embodiment uses a flexible substrate, which enables the fabricated device to be bent and is suitable for wearable electronic applications. The electrode layer thickness is controlled within the range of 2-10 μm, which ensures both sufficient conductivity and matching with the interface morphology of the micron sheet, which is beneficial for the precise deposition of the subsequent micron sheet.

[0052] S2. The micron-sized sheet 3 is uniformly laid on the conductive lower substrate 7 by sieving or electric field-driven dispersion. The pre-patterned substrate obtained in step S1 is fixed to the center of the upper substrate 6 with the electrode face down by polyimide insulating tape. The upper substrate 6 and the lower substrate 7 are arranged in parallel. The distance between the electrode face of the pre-patterned substrate and the micron-sized sheet layer of the lower substrate 7 is controlled to be 2-8 cm.

[0053] Micron-sheet 3 materials include one or more of graphite sheets, silver sheets, Bi₂O₂Se micron-sheets, Te₀.₇Se₀.₃ micron-sheets, and ZnO micron-sheets. The diameter of micron-sheet 3 is 5-200 µm. Micron-sheet 3 can be used after drying in an oven at 50°C.

[0054] (1) Sieving method.

[0055] Select a sieve with an appropriate mesh size according to the diameter range of the micron-sized flakes 3, and sieve them evenly. When the diameter of the micron-sized flakes 3 is 40-50μm, a 300-mesh sieve is most suitable; when the diameter of the micron-sized flakes 3 is 100-200μm, an 80-120-mesh sieve is suitable. The amount of flakes to be laid at one time is 0.3-1.0g, and the optimal amount is about 0.5g. The sieving method is simple to operate and suitable for laboratory and small-to-medium-scale production.

[0056] (2) Electric field driven dispersion method.

[0057] like Figure 4 and Figure 5 As shown, this method is applicable to micron-sized sheets with a strong tendency to aggregate. The specific steps are as follows:

[0058] S21. Place an acrylic insulating support frame 5 on the conductive lower substrate 7, and place the randomly stacked micron flakes on the lower substrate 7; the height of the insulating support frame 5 is 2-8cm.

[0059] S22. Place the upper substrate 6 on top of the insulating support frame 5 to form a closed space between it and the lower substrate 7.

[0060] S23. Apply a voltage of 5-15kV to the upper substrate 6 using a discharge needle, and discharge for 1-10s. The micron-sized sheets move back and forth rapidly in the closed space, colliding and effectively breaking up the aggregates to make them uniformly dispersed. The voltage is preferably 5-13kV and the discharge time is preferably 4-6s.

[0061] S24. After the pressure is stopped, the micron sheets settle uniformly on the lower substrate 7 under the action of gravity, forming a micron sheet layup with uniform dispersion and consistent thickness.

[0062] It should be noted that both the upper and lower substrates in this electric field driven dispersion method are made of metal, with stainless steel substrates being preferred.

[0063] The electric field driven dispersion method achieves solvent-free, dry agglomeration through a dynamic collision mechanism. Compared with methods such as ultrasonic dispersion, it does not introduce solvent contamination, does not change the surface chemical state of the microsheets, and effectively protects the intrinsic physicochemical properties of the microsheets.

[0064] pass Figure 5 It can be seen that the micron-sheets before treatment exhibit significant agglomeration and uneven stacking. After applying an 8kV voltage and discharging for 5 seconds, the uniformity of the micron-sheet layering is significantly improved. If the applied voltage is 13kV and the discharge time is 5 seconds, the micron-sheets are more evenly distributed on the lower substrate 7, with good surface coverage consistency, and their shape matches the shape of the insulating support frame 5 with clear boundaries. Therefore, after multiple experiments, it was found that a dispersion voltage of 5-15kV and a dispersion time of 1-10s are sufficient. Below this range, the dispersion effect is insufficient, while above this range, the movement of the micron-sheets is too violent, which may lead to the breakage of the sheet-like structure.

[0065] S3. Place the discharge tungsten needle 1-10cm directly above the upper substrate 6 and apply a high voltage of 5-25kV to establish a controllable electrostatic field between the upper and lower substrates through the corona discharge mechanism.

[0066] Driven by gravity and electric field, the micron sheet 3 moves between two substrates and is selectively deposited on the non-conductive region of the pre-patterned substrate to form a patterned conductive channel that precisely corresponds to the electrode.

[0067] The micrometer sheet is primarily affected by gravity and electric force. Gravity G = mg, and electric force Fe = qs * Ea, where qs is the saturation charge of the micrometer sheet (the charging process is very fast), and Ea is the electric field strength. When the electric force is greater than the gravity of the micrometer sheet, the micrometer sheet moves upward. The greater the electric force, the greater the upward acceleration of the micrometer sheet.

[0068] Furthermore, the voltage range is 5-13kV: when the voltage is too low, the electric field between the substrates is weak, and the electric force on the microsheet is insufficient to overcome gravity, so it cannot take off effectively; when the voltage is too high, the electric field is too strong and it is easy to cause air gap breakdown, forming a conductive channel (visible electric spark) between the discharge needle and the upper substrate. This not only fails to maintain a stable electric field, but may also damage the substrate and the microsheet.

[0069] Furthermore, the distance between the discharge needle and the substrate should be 1-5cm: if the distance is too large, the corona discharge intensity will be insufficient and the substrate charging rate will be low; if the distance is too small, the discharge needle will have an uneven effect on the substrate and will be prone to breakdown.

[0070] Furthermore, the deposition time is 300ms-3s: if the time is too short, the amount of microsheets deposited on the pre-patterned substrate will be insufficient, and the conductive channels will be discontinuous; if the time is too long, the density of microsheets in the non-conductive area will continue to increase, resulting in multi-layer stacking of microsheets, while the uniformity will decrease, affecting the consistency of the electrical performance of the final device.

[0071] Furthermore, such as Figure 3 As shown, the spacing between the pre-patterned substrate electrode surface and the lower substrate microsheet layup is 2-8 cm. Simulation results show that as the substrate spacing decreases from 8 cm to 2 cm, the electric field strength per unit space is significantly enhanced, which is beneficial for driving efficient deposition of microsheets. When the spacing is too small (<2 cm), the uniformity of the electric field distribution decreases, and local high field strength may cause the movement trajectory of the microsheets to deflect, resulting in blurred edges of the deposition pattern. When the spacing is too large (>8 cm), the electric field strength is insufficient under the same voltage, requiring a higher voltage to drive the microsheets to take off effectively, increasing the difficulty of controlling the process window. Therefore, the optimal spacing range between the upper and lower substrates is 2-8 cm. The specific value needs to be optimized in conjunction with voltage and deposition time to achieve the best deposition effect of the target microsheet material.

[0072] It should be noted that the above ranges represent the optimal intervals for actual operation, and the ranges can be appropriately expanded. The final result is determined by observing the deposition of microsheets under an optical microscope. The optimal condition is that the microsheets are uniformly arranged between the parallel electrodes.

[0073] In summary, COMSOL simulations verify that the electric field strength Ea between the substrates increases with increasing voltage applied by the discharge needle, decreases with decreasing distance between the discharge needle and the upper substrate, and decreases with decreasing distance between the upper and lower substrates. Therefore, by adjusting these three parameters, the electric field between the substrates can be precisely controlled, providing matching field strength conditions for the directional driving of micron-sized and mass-weighted wafers.

[0074] It should be noted that the upper substrate in the micron-scale patterned directional deposition process is made of materials such as PS (polystyrene), Si (silicon), SS (stainless steel), or Cu (copper), and is used to accumulate charge. The lower substrate is made of materials such as SS (stainless steel) or copper.

[0075] S4. The substrate that has completed patterned orientation assembly is encapsulated using a micron-sized film. The micron-sized film is one or more of polyethylene terephthalate (PET), polyimide (PI), and polydimethylsiloxane (PDMS), with a film thickness of 10-20 μm, forming a transparent encapsulation layer.

[0076] Among them, such as Figure 8 As shown, if the substrate has interdigitated electrodes (such as a near-infrared photodetector), the micron film is directly attached to the micron sheet deposition surface, and sealing is achieved through van der Waals forces between the micron film and the micron sheet, which is simple and efficient. Figure 9 It can be seen that the device can effectively respond to 808nm near-infrared light and exhibits a significant photocurrent enhancement effect under positive gate voltage, making it highly valuable for applications.

[0077] If the substrate has parallel electrodes, after the microsheet deposition is completed, the microsheet is transferred from the pre-patterned substrate to the target substrate by the adhesion of the microfilm for final electrical performance testing (similar to tape adhesion). The target substrate is an interdigitated electrode or other electrode structure, forming an electrode (with film)-microsheet-microfilm sandwich structure.

[0078] Electrode leads are drawn out using silver conductive paste or gold wire bonding to ensure reliable connection with external circuits.

[0079] After packaging in step S4, the device still needs to undergo annealing. The specific steps are as follows:

[0080] Place the device in a glove box heated stage protected by an inert gas (nitrogen or argon), heat it to 200℃-240℃ at a slow heating rate of 3-10℃ / min, hold it at that temperature for 20-60 minutes, and then allow it to cool naturally to room temperature.

[0081] like Figure 6 As shown, the above-mentioned thermal annealing treatment can significantly improve the interfacial contact quality between the microsheet and the electrode. During the heat treatment process, organic contaminants (such as solvent residue, moisture, oxides, etc.) at the interface between the microsheet and the metal electrode are removed, and the electrode metal atoms undergo a certain degree of surface diffusion, forming a tighter metal-semiconductor ohmic contact with the microsheet, significantly reducing the contact resistance.

[0082] After step S4, which involves packaging or annealing, the device also needs to undergo a water vapor capillary filling enhancement process. The specific steps are as follows:

[0083] Place the device in a humidity control box or a saturated salt solution humidity regulator and control the relative humidity to 85%-97% to expose it to water vapor for 12-24 hours. This allows water vapor to condense capillarily in the gaps between the micron sheet and the electrode and fill the gaps.

[0084] Subsequently, the sensor is dried in a 50℃ forced-air oven for 2-10 hours or heated on an 80℃ hot table for 5-10 minutes to remove moisture, increase the effective contact area between the micron sheet and the electrode, and further improve the sensor's performance (e.g., ...). Figure 7 (As shown).

[0085] The present invention also provides a device for electrostatic field-induced microsheet patterning orientation assembly, comprising a substrate, electrodes pre-patterned on the substrate, microsheets, and an encapsulation layer, wherein the microsheets cover the non-conductive regions of the electrodes and form electrical contacts with the electrodes.

[0086] The device may be a photodetector (suitable for near-infrared, visible light, and other wavelengths), a flexible pressure sensor, a tactile sensor, or other functional microelectronic devices, the specific function of which is determined by the selected micron sheet material and electrode pattern.

[0087] Distance between discharge pin and upper substrate (mm) Voltage (kV) Micron-sheet materials Pre-patterned electrode spacing (µm) Deposition time (s) Example 1 10 15 Graphite sheet 200 1 Example 2 10 15 <![CDATA[Bi2O2Se microplate]]> 200 3 Example 3 10 15 <![CDATA[Bi2O2Se microplate]]> 50 3

[0088] Examples 1-3, through experiments, show that, as indicated in the table above, under the premise of a discharge needle distance of 10mm from the substrate and an applied voltage of 15kV, Example 1 verifies that graphite sheets with a large-pitch (200μm) pre-patterned electrode spacing can complete patterned directional deposition in just 1 second, with deposition results as shown in the table. Figure 10 As shown; Example 2 verified that Bi2O2Se microsheets with a large-pitch (200 μm) pre-patterned electrode spacing can complete patterned directional deposition in only 3 seconds; Example 3 verified that Bi2O2Se microsheets with a small-pitch (50 μm) pre-patterned electrode spacing can complete patterned directional deposition in only 3 seconds. The deposition effects of Bi2O2Se microsheets in Examples 2 and 3 are as follows. Figure 11 and Figure 12 As shown, and through Figure 13 It was found that the device has a wide gate voltage range optical response capability for 808nm near-infrared light.

[0089] This invention has the following outstanding technical effects and advantages:

[0090] (1) Green dry assembly process without masks, contact, or solvents. The entire patterned orientation assembly process is completed in a dry state and driven by non-contact electrostatic force. No masks, templates, or solvent media are required, which completely eliminates the risk of contamination introduced by auxiliary materials and protects the intrinsic physicochemical properties of micron-sized sheets to the greatest extent. The process is highly clean.

[0091] (2) The process is simple, the cost is low, and the production efficiency is high. The only equipment required is a high-voltage power supply, a discharge needle and a parallel substrate cavity. The structure is simple and the cost is extremely low. The pre-patterned electrode is a functional component of the device and does not need to be removed after the assembly function is completed, so there is no waste of disposable consumables. The assembly time is only 300ms-30s, and the process efficiency is significantly better than the existing liquid phase assembly method (which usually takes several minutes to tens of minutes), which is conducive to high-throughput batch preparation.

[0092] (3) The assembly behavior is precise and controllable, and the device consistency is good. By adjusting parameters such as the discharge voltage (5-25kV), the distance between the discharge pin and the upper substrate (1-10cm), the distance between the upper and lower substrates (2-8cm), and the number and arrangement of the discharge pins, the electric field strength and distribution between the upper and lower substrates can be precisely controlled, thereby precisely controlling the movement speed, flight trajectory and deposition density of the micro-wafers, and realizing the control of the assembly density of micro-wafers from single layer to multilayer. The high degree of agreement between COMSOL simulation and experimental results provides a reliable theoretical basis for the pre-design of process parameters.

[0093] (4) It has strong universality and is applicable to a wide range of material systems. The electrostatic field-induced assembly principle of this invention has no stringent requirements on the material system of the micron sheet. It has been verified that it can be used for the patterned assembly of various materials such as graphite sheet, silver sheet, Bi2O2Se, Te0.7Se0.3, and ZnO. Theoretically, it is applicable to all dry micro-sheet functional materials that can be induced to charge in an electric field.

[0094] (5) Multifunctional device integration and fabrication capability. By replacing micron-sized sheet materials with different functions and cooperating with corresponding pre-patterned electrode designs, this invention can fabricate a variety of functional devices such as photodetectors (utilizing the near-infrared light absorption characteristics of Bi2O2Se), pressure sensors (utilizing the piezoresistive effect of graphite sheets), and tactile sensors on the same process platform, with strong platform compatibility and functional expansion capability.

[0095] (6) Annealing and post-processing techniques such as water vapor capillary filling work synergistically to further improve device performance. Annealing significantly improves the ohmic contact between the micron sheet and the electrode, while water vapor capillary filling effectively increases the effective contact area of ​​the interface. Both can be used alone or in combination to significantly improve the photocurrent response or sensing sensitivity of the device, providing multi-dimensional post-processing methods for on-demand control of device performance.

[0096] 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.

[0097] 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. A method for fabricating a device based on electrostatically induced microsheet patterned orientation assembly, characterized in that, Includes the following steps: S1. Prepare a pre-patterned electrode and print or deposit it on a substrate to obtain a pre-patterned substrate; S2. The micron-sized sheet is evenly laid on the lower substrate, and the pre-patterned substrate is placed between the lower substrate and the upper substrate. S3. A controllable electric field is formed between the upper and lower substrates by corona discharge. The micron sheet is driven by the electric field force to be deposited on the non-conductive area of ​​the pre-patterned substrate, forming a patterned conductive channel that precisely corresponds to the electrode. S4. Encapsulate the substrate after completing the graphical orientation assembly.

2. The method for fabricating a device based on electrostatically induced microsheet patterned orientation assembly according to claim 1, characterized in that, In step S2, the micron-sized sheets are uniformly deposited on the lower substrate by sieving or electric field-driven dispersion.

3. The method for fabricating a device based on electrostatically induced microsheet patterned orientation assembly according to claim 2, characterized in that, The electric field-driven dispersion method includes the following steps: S21. Place an insulating support frame on the lower substrate and place the messy micron flakes on the lower substrate; S22. Place the upper substrate on top of the insulating support frame to form a closed space between it and the lower substrate; S23. Using corona discharge, the micron sheet moves and collides rapidly in a closed space; S24. After the pressure is stopped, the micron-sized sheets fall and are evenly dispersed on the lower substrate.

4. The method for fabricating a device based on electrostatically induced microsheet patterned orientation assembly according to claim 3, characterized in that, The voltage applied for dispersing the micron-sized sheets is 5-15 kV, and the time is 1-10 s.

5. The method for fabricating a device based on electrostatically induced microsheet patterned orientation assembly according to claim 1, characterized in that, The substrate includes one or more of polyethylene terephthalate, polyimide, polydimethylsiloxane, nonwoven fabric, and paper, with a substrate thickness of 20-100 μm; the electrode includes one or more of gold, silver, copper, cadmium, aluminum, indium tin oxide, and graphite, with an electrode layer thickness of 2-10 μm.

6. The method for fabricating a device based on electrostatically induced microsheet patterned orientation assembly according to claim 1, characterized in that, In step S3, the voltage driving the deposition of the micron sheet is 5-25kV, the distance between the discharge needle and the upper substrate is 1-10cm, the spacing between the pre-patterned substrate electrode surface and the micron sheet layer on the lower substrate is 2-8cm, and the deposition time is 300ms-30s.

7. The method for fabricating a device based on electrostatically induced microsheet patterned orientation assembly according to claim 1, characterized in that, In step S4, the substrate that has completed patterned orientation assembly is encapsulated with a micron film. The micron film is one or more of polyethylene terephthalate, polyimide, and polydimethylsiloxane, and the film thickness is 10-20 μm. The electrode leads are led out through silver conductive paste or gold wire bonding.

8. The method for fabricating a device based on electrostatically induced microsheet patterned orientation assembly according to claim 1, characterized in that, After packaging in step S4, the device still needs to undergo annealing. The specific steps are as follows: Place the device in a glove box hot stage, heat it to 200℃-240℃, keep it at that temperature for 20-60 minutes, and then let it cool naturally to room temperature.

9. The method for fabricating a device based on electrostatically induced microsheet patterned orientation assembly according to claim 1, characterized in that, After the packaging process in step S4 is completed, the device also needs to undergo a water vapor capillary filling enhancement treatment. The specific steps are as follows: Place the device in a water vapor environment with a relative humidity of 85%-97% for 12-24 hours to allow water vapor to condense capillarily in the gaps between the micron sheet and the electrode and fill the gaps. Then, dry in a 50℃ forced-air oven for 2-10 hours or heat on an 80℃ hot table for 5-10 minutes to remove moisture.

10. A device based on electrostatically induced micron-sheet patterned orientation assembly, characterized in that, It includes a substrate, electrodes pre-patterned on the substrate, microsheets, and an encapsulation layer, wherein the microsheets cover the non-conductive regions of the electrodes and form electrical contacts with the electrodes.

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