Independent controllable array extraction electrode electrofluid nozzle

Abstract

The invention belongs to the related technical field of ink-jet printing, and discloses an independent controllable array extraction electrode electrofluid sprayer which is characterized in that the bottom of an ink box is connected with an integrated nozzle chip, an ink outlet is formed in the bottom of the ink box, and a plurality of nozzle structures arranged in an array are arranged at the position, corresponding to the ink outlet, of the integrated nozzle chip; a groove is formed in the side, away from the ink box, of the integrated nozzle chip, a boss is arranged at the bottom of the groove, and an ink flow channel penetrating through the integrated nozzle chip is formed in the middle of the boss, so that a nozzle structure is formed. An annular extraction electrode is arranged on the periphery of the groove and connected with the control circuit board through a thin film wire. The control circuit board is used for controlling the voltage of the extraction electrode to adjust the electric field intensity between the extraction electrode and the ink so as to control the printing behavior of the corresponding nozzle structure. According to the invention, the integrated density production efficiency of the array electrofluid nozzle can be effectively improved, and finally high-resolution on-demand ink-jet printing is realized.

Description

Technical Field

[0001] This invention belongs to the technical field of inkjet printing, and more specifically, relates to an independently controllable arrayed extraction electrode current fluid printhead. Background Technology

[0002] Electrohydrodynamic printing uses an electric field to induce functional ink to be ejected from the nozzle onto the substrate, enabling the precise fabrication of micro- and nano-scale patterned structures. Unlike the "extrusion" principle of traditional inkjet printing, this technology employs a "stretching" printing mechanism, utilizing the potential difference between the nozzle and the substrate to pull the ink out of the nozzle to form a conical jet. It boasts significant advantages such as high resolution (<0.2μm), a wide range of ink viscosity adaptability (1–10000cps), and multi-mode printing (on-demand dot spraying / jet direct writing / atomization film formation), demonstrating immense potential in fields such as flexible electronics, novel displays, and biomanufacturing.

[0003] Despite the outstanding performance of electrofluid printing technology, its industrial application is still limited by printhead frequency and integration density. To improve production efficiency, arrayed electrofluid printheads have become an inevitable choice. However, existing arraying solutions suffer from severe electric field crosstalk problems: the non-uniform electric field formed between adjacent nozzles generates lateral electric field components, leading to jet deflection, decreased droplet landing accuracy, and deterioration of liquid film uniformity. To suppress crosstalk, current technology is forced to increase the nozzle spacing, resulting in a sharp reduction in the number of nozzles per unit area, which greatly limits the printhead integration density and cannot meet the large-area, high-efficiency manufacturing requirements of high-resolution display devices such as OLEDs / QLEDs with a PPI greater than 300. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides an independently controllable arrayed extraction electrode current fluid printhead. This addresses the problem of severe electric field crosstalk in existing arrayed current fluid printhead solutions, which limits printhead integration density and hinders industrial applications. The aim is to effectively achieve independent control of the arrayed current fluid printhead's ejection, reduce the impact of printing height on the printing process, suppress electric field crosstalk between adjacent nozzles, and improve electric field utilization, thereby increasing the integration density and production efficiency of the arrayed current fluid printhead and ultimately achieving high-resolution on-demand inkjet printing.

[0005] To achieve the above objectives, according to one aspect of the present invention, an independently controllable arrayed extraction electrode electrohydrodynamic nozzle is provided, comprising an ink cartridge, an integrated nozzle chip, an extraction electrode, a thin-film wire, a control circuit board, and a high-voltage electrode; the bottom of the ink cartridge is connected to the integrated nozzle chip, the bottom of the ink cartridge has an ink outlet, and the integrated nozzle chip has multiple nozzle structures arranged in an array corresponding to the ink outlet; the integrated nozzle chip has a groove on the side away from the ink cartridge, a boss is provided on the bottom of the groove, the height of the boss is less than the depth of the groove, and there is an annular gap between the boss and the inner wall of the groove, and an ink flow channel penetrating the integrated nozzle chip is provided in the middle of the boss, thereby forming the nozzle structure; The integrated nozzle chip has an annular extraction electrode on the side of the surface opposite to the ink cartridge surrounding the groove. The extraction electrode is connected to the control circuit board via a thin-film wire. The control circuit board is also connected to the high-voltage electrode, which is inserted into the ink cartridge to apply a high voltage to the ink inside, making the ink positively charged. The control circuit board is used to control the voltage of the extraction electrode to adjust the electric field strength between the electrode and the ink, thereby controlling the printing behavior of the corresponding nozzle structure.

[0006] According to the independently controllable arrayed extraction electrode electrohydrodynamic nozzle provided by the present invention, the groove is a circular groove, the boss is a circular boss, and the extraction electrode is annular.

[0007] According to the independently controllable arrayed extraction electrode electrofluid nozzle provided by the present invention, a plurality of nozzle structures are arranged in two rows, and the two rows of nozzle structures are arranged in a triangular array; the extraction electrodes corresponding to the plurality of nozzle structures are connected to the control circuit board through a plurality of thin film wires distributed on both sides of the nozzle structure and parallel to each other.

[0008] According to the independent controllable arrayed extraction electrode electrofluid nozzle provided by the present invention, an insulating layer is respectively formed on both sides of the integrated nozzle chip by thermo-oxidative growth, and a dielectric layer is further formed on the surface of the insulating layer; a passivation layer is formed on the surface of the extraction electrode by deposition.

[0009] According to the independently controllable arrayed extraction electrode electrofluid nozzle provided by the present invention, the maximum outer radius of the extraction electrode is determined according to the following formula: ; in, This represents the outer radius of the extraction electrode. This indicates the distance between the axes of adjacent nozzle structures. This indicates the minimum spacing required for adjacent extraction electrodes to undergo electrical breakdown when a preset high voltage and low voltage are applied, respectively.

[0010] According to the independently controllable arrayed extraction electrode electrofluid nozzle provided by the present invention, the minimum width of the extraction electrode is determined according to the following formula: ; in, This represents the dimensionless width of the extraction electrode; This represents the dimensionless inner radius of the extraction electrode; This represents the dimensionless height of the extraction electrode from the lower end of the boss; This indicates the outer radius of the boss; , , These represent the outer radius, inner radius, and height from the boss of the extraction electrode, respectively.

[0011] The independently controllable arrayed extraction electrode electrofluid nozzle provided by the present invention provides a minimum threshold electrocolumn coefficient for controlling the extraction electrode voltage at which printing behavior occurs. for: ; in, The dimensionless electrocapillary coefficient represents the amount of material that is absorbed when the nozzle structure is engaged in printing. The vacuum permittivity, This represents the electric field strength generated between the protrusion and the extraction electrode. This indicates the radius of the ink flow channel. This indicates the surface tension coefficient of the ink used when the nozzle structure is printing.

[0012] The independently controllable arrayed extraction electrode current fluid nozzle provided by the present invention has an outer radius of the boss. and the height of the extraction electrode from the boss Determined by the following formula: ; in, The minimum electric field strength required to induce jetting behavior. The high voltage applied inside the ink cartridge. To extract the voltage value applied to the electrode.

[0013] According to the independently controllable arrayed extraction electrode current fluid nozzle provided by the present invention, the bottom of the ink cartridge is provided with an opening, the ink cartridge is detachably connected to an end cap at the bottom opening, the end cap is provided with a mounting groove on the side facing the integrated nozzle chip, the bottom of the mounting groove is provided with a penetrating ink outlet, and the integrated nozzle chip is detachably installed in the mounting groove.

[0014] The independently controllable arrayed extraction electrode current fluid nozzle provided by the present invention further includes an ink supply system, the ink supply system including an ink tower and an ink supply tube, the ink cartridge having an ink through hole, the ink tower being detachably and sealingly connected to the ink through hole, and the ink supply tube being used to connect the ink tower and the ink pool. The ink cartridge has a protrusion for connecting to a mobile printing platform.

[0015] In summary, compared with the prior art, the independently controllable arrayed extraction electrode electrofluid nozzle provided by the present invention offers the following advantages: 1. By setting an annular extraction electrode at the bottom of each nozzle and adopting a differentiated voltage application strategy (applying low voltage or ground to the activated nozzle and high voltage to the non-activated nozzle), the electric field strength of a single nozzle can be precisely controlled. When a nozzle needs to eject ink, the low voltage or grounding increases the potential difference between the ink channel and the extraction electrode. The electric field strength at structures such as the annular gap and circular groove exceeds the Taylor cone formation threshold, triggering ink ejection. Meanwhile, the non-activated nozzle has an insufficient electric field strength to trigger ejection because the extraction electrode maintains a high voltage. This "on-demand triggering" mechanism breaks through the limitations of traditional array printheads that require intermittent opening or rely on external electrode arrays. It can realize independent opening and closing control of any nozzle, significantly improving the flexibility and controllability of the printing process. It is especially suitable for high-precision on-demand dot printing of complex patterns and electrostatic spinning scenarios. 2. The core of the independently controllable arrayed electro-hydraulic nozzle is that each nozzle structure is equipped with a dedicated annular extraction electrode and an independent thin-film wire, forming a one-to-one control channel. The extraction electrode, together with the nozzle inner wall, annular gap, and circular groove, constitute a closed electric field constraint structure: the nozzle inner wall acts as an insulating barrier, confining the electric field of a single nozzle within the annular space between the boss and the extraction electrode, thereby suppressing electric field crosstalk between adjacent nozzles and improving electric field utilization. 3. The proposed annular extraction electrode, together with the inner wall of the nozzle, forms a Faraday cage-like encapsulation structure, which constrains the distribution of the electric field inside a single nozzle, reduces its crosstalk effect on adjacent nozzles, reduces the distance between the axes of adjacent nozzles, increases the number of nozzles distributed per unit area, improves the working efficiency of the arrayed electro-hydraulic printhead during printing, and enables large-area high-resolution on-demand inkjet printing. 4. The proposed annular extraction electrode is integrated into the lower end face of the arrayed printhead nozzle chip, forming an integral structure with the printhead. This confines the control electric field between the lower end protrusion of the ink flow channel and the lower end extraction electrode of the nozzle, eliminating the need to apply electrodes to the bottom of the printing substrate. This design focuses the electric field within a sub-millimeter spatial range, increasing the printing electric field intensity to [value missing]. This greatly improves the efficiency of electric field utilization and reduces the substrate effect that reduces printing accuracy due to uneven electric field distribution between the nozzle and the substrate electrodes, and reduces the impact of printing height on the arrayed electrohydrodynamic nozzle. 5. Further, by optimizing the geometry of the annular gap and circular groove, the electric field lines are concentrated in the meniscus liquid surface region of the nozzle, while the electric field interference to adjacent nozzles is reduced to below the threshold. This structural design physically severs the electric field coupling between adjacent nozzles, providing a structural basis for independent nozzle control. The proposed voltage setting design principle for the annular extraction electrode reduces the high voltage value during jetting by designing the voltage setting, so that the potential difference between the upper and lower parts of the nozzle is slightly greater than the voltage threshold for jetting behavior, reducing the possibility of electrical breakdown between adjacent nozzles and improving the working stability of the arrayed current fluid printhead during printing. 6. The proposed extraction electrode is connected to its adjacent thin-film wire, enabling integrated deposition and fabrication of the electrode and wire; the proposed extraction electrode is connected to the control circuit board via thin-film wire, with each wire corresponding to the other, enabling integrated management. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an independently controllable arrayed extraction electrode current fluid nozzle provided in an embodiment of the present invention.

[0017] Figure 2 An exploded view of an independently controllable arrayed extraction electrode current fluid nozzle provided in an embodiment of the present invention.

[0018] Figure 3 A cross-sectional view of an ink cartridge provided in an embodiment of the present invention.

[0019] Figure 4 This is a partially enlarged view of a single nozzle structure in the cross-sectional view of the integrated nozzle of the independently controllable arrayed extraction electrode current fluid nozzle provided in an embodiment of the present invention.

[0020] Figure 5 The image shows a bottom view of an integrated nozzle for an independently controllable arrayed extraction electrode current fluid nozzle provided in an embodiment of the present invention.

[0021] Figure 6 The diagram shows the overall logic structure of the independently controllable arrayed extraction electrode current fluid nozzle and its supporting device when working together, as provided in the embodiments of the present invention.

[0022] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1 is the ink cartridge; 11 is the end cap; 111 is the mounting slot; 112 is the ink outlet; 12 is the protrusion; 13 is the electrode through hole; 14 is the ink through hole; 15 is the ink cavity; 16 is the shallow end cap groove; 21 is the ink tower; 22 is the ink supply tube; 31 is the control circuit board; 32 is the high-voltage electrode; 33 is the power supply cable; 4 is the integrated nozzle chip; 41 is the ink flow channel; 42 is the circular boss; 43 is the annular gap; 44 is the circular groove; 45 is the inner wall of the printhead; 46 is the extraction electrode; 47 is the thin film wire. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0024] Please see Figure 1 and Figure 2 This embodiment provides an independently controllable arrayed extraction electrode 46 electro-hydraulic nozzle. The nozzle includes an ink cartridge 1, an integrated nozzle chip 4, extraction electrodes 46, thin film wires 47, a control circuit board 31, and a high-voltage electrode 32. The bottom of the ink cartridge 1 is connected to the integrated nozzle chip 4, and the bottom of the ink cartridge 1 is provided with an ink outlet 112. The integrated nozzle chip 4 is provided with multiple nozzle structures arranged in an array corresponding to the ink outlet 112. The integrated nozzle chip 4 is provided with a groove on the side away from the ink cartridge 1. A boss is provided on the bottom of the groove. The height of the boss is less than the depth of the groove, and there is an annular gap 43 between the boss and the inner wall of the groove. An ink flow channel 41 penetrating the integrated nozzle chip 4 is provided in the middle of the boss, thereby forming the nozzle structure. The integrated nozzle chip 4 has an annular extraction electrode 46 on the side of the surface opposite to the ink cartridge 1 around the groove. The extraction electrode 46 is connected to the control circuit board 31 via a thin film wire 47. The control circuit board 31 is also connected to the high voltage electrode 32. The high voltage electrode 32 is inserted into the interior of the ink cartridge 1 to apply a high voltage to the ink inside, making the ink positively charged. The control circuit board 31 is used to control the voltage of the extraction electrode 46 to adjust the electric field strength between the electrode and the ink, thereby controlling the printing behavior of the corresponding nozzle structure.

[0025] In this embodiment, the independent controllability of the arrayed electro-hydraulic nozzle is achieved by the following characteristics: Ink in the printhead is positively charged by a high voltage applied by the needle-shaped high voltage electrode 32. When it flows from the ink cartridge 1 through the ink outlet 112 and the ink channel 41 to the lower end of the ink channel 41 of each nozzle, it forms a downward-facing meniscus liquid surface on the protrusion at the outlet at the lower end of the channel due to the surface tension of the ink. By applying a specific low voltage to the extraction electrode 46 of the nozzle that needs to start the printing process, the potential difference between the ink channel 41 and the extraction electrode 46 is changed, so that the electric field strength distributed in the annular gap 43, groove, and inner wall of the printhead 45 (i.e., the inner wall of the groove) is higher than the threshold voltage that causes the ink to generate a Taylor cone and eject, thus causing ejection. For other extraction electrodes 46 that do not start the printing process, a high voltage is applied so that the ink is not high enough to cause ejection, so that the electric field strength is lower than the ejection threshold voltage, thus preventing the corresponding printhead from ejecting. This achieves independent control of the ejection of the arrayed current fluid printhead. Each nozzle's extraction electrode 46 forms an independent control channel with the control circuit via a thin-film wire 47. The thin-film wire 47 is only connected to the extraction electrode 46 of its corresponding single nozzle, and there is no electrical connection between the thin-film wires 47 of different nozzles. The control circuit board 31 controls the voltage of each extraction electrode 46 through the thin-film wire 47. For example, a low voltage is applied to the extraction electrodes 46 of one or more nozzles in the nozzle array, while the extraction electrodes 46 of other nozzles remain at a high voltage, thereby achieving the purpose of ejecting these nozzles and realizing the on-demand printing of functional ink using current. The annular gap 43, the groove, and the inner wall 45 of the printhead together constitute an electric field constraint structure, concentrating the electric field of a single nozzle in the space between the boss and the extraction electrode 46, thereby suppressing electric field crosstalk between adjacent nozzles.

[0026] The integrated nozzle chip 4 is obtained by setting it in the following way: Multiple grooves are evenly spaced and arranged in a multi-row array using etching or other methods on the lower surface of the nozzle substrate (chip). Above each groove, an annular groove (annular gap 43) is coaxially formed using etching or other methods, simultaneously creating a circular boss 42 and the nozzle inner wall 45. An extraction electrode 46 and thin-film wires 47 are formed on the bottom outer side of the nozzle inner wall 45 using patterned deposition of a conductor material. The electrode is connected to the two end faces of the chip via multiple parallel wires distributed on both sides of the lower end face of the integrated nozzle, and then connected to the control circuit board 31 to achieve potential control of the extraction electrode 46. Figure 1 , Figure 2As shown, the integrated nozzle can be composed of a plurality of integrated individual nozzles, each with its own structure. The extraction electrode 46 of each nozzle can be connected to the control circuit board 31 via a thin-film wire 47, and can be connected to a high-potential, low-potential power supply, or grounded, respectively. The control circuit board 31 is used to control the voltage of the extraction electrode 46 to a low-potential voltage or grounded to control the corresponding nozzle structure to perform printing behavior, and to control the voltage of the extraction electrode 46 to a high-potential voltage to prevent the corresponding nozzle structure from performing printing behavior.

[0027] The lower end face of the ink cartridge 1 is coaxially arranged with each ink channel 41 corresponding to the integrated nozzle below by means of etching, drilling, etc.; the rest of the lower end face of the ink cartridge 1 should be transitionally fitted with the upper end face of the integrated nozzle, and a sealing adhesive coating is provided between the two.

[0028] In some embodiments, the groove is a circular groove 44, the boss is a circular boss 42, and the extraction electrode 46 is annular. The integrated nozzle includes a plurality of nozzles and an extraction electrode 46 disposed on the lower end face of each nozzle and a thin film wire 47 connected thereto. Each nozzle includes an ink channel 41, a circular boss 42, an annular gap 43, a circular groove 44, and an inner wall 45 of the nozzle arranged coaxially in sequence.

[0029] In some embodiments, the integrated nozzle chip 4 is an array of nozzles consisting of multiple repeating structures having at least one row of nozzle structures, with equal axial spacing between any two adjacent nozzles. Optionally, the multiple nozzle structures are arranged in two rows, and the two rows of nozzle structures are arranged in a triangular array; the extraction electrodes 46 corresponding to the multiple nozzle structures are connected to the control circuit board 31 through multiple thin-film wires 47 distributed on both sides of the nozzle structures and parallel to each other. The control circuit board 31 is connected to the thin-film wires 47 on both sides of the integrated nozzle chip 4 via power supply cables 33.

[0030] In some embodiments, insulating layers are formed on both sides of the integrated nozzle chip 4 by thermo-oxidative growth, and a dielectric layer is also formed on the surface of the insulating layer; a passivation layer is formed on the surface of the extraction electrode 46 by deposition.

[0031] In some embodiments, the maximum outer radius of the extraction electrode 46 is determined according to the following formula: ; in, This indicates the outer radius of the extraction electrode 46. This indicates the distance between the axes of adjacent nozzle structures. This represents the minimum spacing required for adjacent extraction electrodes 46 to undergo electrical breakdown when a preset high voltage and low voltage are applied, respectively. When the width of the extraction electrode ring 46 of each nozzle and the distance to the extraction electrode ring 46 of adjacent nozzles satisfy the above formula, the electric field generated by the nozzle on one side of the extraction electrode 46 will not act on the meniscus of the nozzle on the other side or on the ejected ink droplets, and electrical breakdown will not occur when high voltage and low voltage are applied to the electrodes on both sides, respectively.

[0032] Furthermore, for each nozzle, the outer diameter of the boss should be greater than the outer diameter of the ink flow channel 41, the inner diameter of the annular gap 43 (i.e., the annular groove) should be equal to the outer diameter of the boss, the outer diameter of the circular groove 44 should be greater than or equal to the outer diameter of the annular groove, the inner diameter of the nozzle inner wall 45 should be equal to the outer diameter of the annular groove and the circular groove 44 at the corresponding heights, and the inner diameter of the extraction electrode 46 should be greater than or equal to the inner diameter of the nozzle inner wall 45.

[0033] In some embodiments, the minimum width of the extraction electrode 46 is determined according to the following formula: ; in, This indicates the dimensionless width of the extraction electrode 46; This represents the dimensionless inner radius of the extraction electrode 46; This represents the dimensionless height of the extraction electrode 46 from the lower end of the boss; This indicates the outer radius of the boss; , , These represent the outer radius, inner radius, and height from the boss of the extraction electrode 46, respectively. The minimum width is determined based on extensive numerical calculations of the process phase diagram of the arrayed electro-hydraulic nozzle under different operating conditions. It is the minimum width at which the extraction electrode 46 causes the arrayed electro-hydraulic nozzle to exhibit jetting behavior, summarized from its boundaries. Specifically, it is obtained by adjusting the dimensionless width and performing numerical calculations to analyze the occurrence of jetting behavior, then fitting the obtained minimum width. If the width is less than this, it is difficult to induce jetting behavior. The actual width of the extraction electrode 46, i.e., the difference between its outer and inner diameters, should be greater than or equal to the aforementioned minimum width.

[0034] In some embodiments, the minimum threshold electrocoefficient of the voltage of the extraction electrode 46 used to control the occurrence of printing behavior for: ; in, The dimensionless electrocapillary coefficient represents the amount of material that is absorbed when the nozzle structure is engaged in printing. The vacuum permittivity, This indicates the electric field strength generated between the protrusion and the extraction electrode 46. This indicates the radius of the ink flow channel 41. This represents the surface tension coefficient of the ink used when the nozzle structure prints. The minimum threshold electrocapillary coefficient, or the minimum threshold of the electrocapillary coefficient, is determined based on extensive numerical calculations to obtain the process phase diagram of the arrayed electrofluid printhead under different operating conditions. The threshold electrocapillary coefficient summarizing the printhead's ejection behavior based on its boundaries can be used to determine the minimum electric field strength that can trigger ejection behavior, and thus determine the control voltage threshold for the extraction motor.

[0035] Simultaneously satisfying the aforementioned two geometric parameters and electric field control design criteria for the extraction electrode 46—namely, the minimum width and minimum threshold electrocapillary coefficient criteria—can effectively guarantee the independent controllability of each nozzle in the independently controllable arrayed extraction electrode 46 electrofluid printhead. It also minimizes the impact of the electric field generated by high-pressure ink on one side of adjacent nozzles on the meniscus, jet, and ink droplets at the tip of the other nozzle, thus suppressing electric field crosstalk between nozzles. Furthermore, it reduces the possibility of electrical breakdown between the rings of the extraction electrodes 46 of adjacent nozzles and improves electric field utilization efficiency. Designing the annular extraction electrode 46 using this design criterion simplifies the printhead structure and reduces manufacturing costs to the greatest extent possible while ensuring the printhead's independent controllability.

[0036] In some embodiments, for a distance of [height] from the nozzle boss, The characteristic electric field intensity excited at the tip of the nozzle's axis of symmetry by the extraction electrode 46 ring can be approximated as: , To extract the characteristic electric field intensity generated by electrode 46 at the tip of the nozzle's axis of symmetry, the outer radius of the boss under this operating condition can be designed using this formula, combined with the relationship between the initiation voltage and the electrode geometry, and the expected control voltage value. and the height of the extraction electrode 46 from the boss Specifically, it is determined by the following formula: ; in, The minimum electric field strength required to induce jetting behavior. The high voltage value applied inside ink cartridge 1 To extract the voltage value applied to electrode 46, a preset control voltage value can be used.

[0037] Furthermore, as a preferred embodiment, when the extraction electrode 46 is grounded, i.e. At the same time, the extraction electrode 46 can reduce electric field crosstalk between array nozzles to a certain extent and improve the integration density of array nozzles. Based on the uniqueness theorem of the electrostatic boundary value problem: In the formula, The vacuum permittivity, Let k be the surface of conductor k, n represent the normal direction, and U represent the constant potential distribution when all conductors are uncharged. The closed, grounded conductor shell can shield the mutual influence of the electric fields inside and outside the shell, thus giving the nozzle tip area surrounded by the extraction electrode ring 46 a certain degree of anti-crosstalk capability. The width of the extraction electrode ring 46 of each nozzle and the distance from the extraction electrode ring 46 of adjacent nozzles satisfy the following: the electric field generated by the nozzle on one side of the extraction electrode 46 will not act on the meniscus of the nozzle on the other side or on the ejected ink droplets, and no electrical breakdown will occur when high voltage and low voltage are applied to the electrodes on both sides respectively.

[0038] In some embodiments, the ink cartridge 1 has an opening at the bottom, and the ink cartridge 1 is detachably connected to the end cap 11 at the bottom opening. The end cap 11 has a mounting groove 111 on the side facing the integrated nozzle chip 4. The bottom of the mounting groove 111 has a penetrating ink outlet 112, and the integrated nozzle chip 4 is detachably installed in the mounting groove 111.

[0039] In some embodiments, the printhead further includes an ink supply system, which includes an ink tower 21 and an ink supply tube 22. The ink cartridge 1 is provided with an ink through hole 14. The ink tower 21 is detachably and sealingly connected to the ink through hole 14. The ink supply tube 22 is used to connect the ink tower 21 and the ink pool. The ink cartridge 1 has a protrusion 12 for connecting to a mobile inkjet printing platform.

[0040] Specifically, the ink cartridge 1 includes an end cap 11 for engaging the nozzle, a protrusion 12 fixed to the moving platform, an electrode through hole 13 for inserting the high-voltage electrode 32, an ink through hole 14 for inserting the ink tower 21, an ink cavity 15 for holding functional ink, and a shallow end cap groove 16 for mounting the end cap 11. All edges inside the cavities of the ink cartridge 1 are rounded; all edges on the lower end face of the printhead, except for the extraction electrode 46, are rounded.

[0041] In some embodiments, such as Figure 2 and Figure 3As shown, the ink cartridge 1 is made of insulating resin material through injection molding, 3D printing, or photopolymerization additive manufacturing. Its overall shape is similar to a cuboid. The two outer sides connected to the moving platform have protrusions 12 with through holes for fixing to the moving platform shaft with bolts. On the upper end face connected to the control circuit board 31, there are three electrode through holes 13 distributed along the long central axis of the upper end face and connected to the lower ink cavity 15 for inserting columnar electrodes to bring high voltage to the ink. At each end of the central axis of the upper end face, there is an ink through hole 14 connected to the lower ink cavity 15 for inserting the pagoda structure connecting the ink tube and the ink cartridge 1. On the lower end face connected to the integrated nozzle chip 4, there is an ink cavity 15 distributed along the long central axis of the lower end face for holding printing function ink. Below the ink cavity 15, there is a shallow end cap groove 16 slightly wider than the ink cavity 15 for installing and sealing the ink cavity 15 and connecting the end cap 11 of the integrated nozzle so that the ink can flow fully to the integrated nozzle.

[0042] This can be considered as a preferred implementation method, see reference. Figure 3 The end cap 11 is also made of insulating resin material through injection molding, 3D printing or photopolymerization, etc. It is a rectangular thin sheet with a very large aspect ratio. Its length and width dimensions are the same as the shallow end cap groove 16 of the ink cartridge 1. A rectangular groove, namely the mounting groove 111, is provided in the middle of the lower end face of the end cap 11 for fixing the integrated nozzle chip 4. A rectangular through hole, namely the ink outlet 112, is provided in the middle of the upper end face of the end cap 11. The area is smaller than the rectangular groove and larger than the area of ​​the nozzle distribution area of ​​the integrated nozzle chip 4. It is used to connect the ink cavity 15 of the ink cartridge 1 with the inlet of the ink flow channel 41 of the integrated nozzle chip 4, and to allow the ink in the ink cartridge 1 to flow fully into the ink flow channel 41 of the integrated nozzle.

[0043] This can be used as a preferred implementation method, such as Figure 1 , Figure 2 , Figure 4As shown, the integrated nozzle chip 4 is fabricated from insulating materials such as glass or dielectric materials such as silicon wafers using micro-nano manufacturing techniques such as etching and deposition. To improve processing efficiency, its overall shape is a square thin sheet with a large width-to-height ratio, and its side length is the same as the long side of the rectangular groove on the end cap of the ink cartridge 1. On its substrate-facing side, several rows of equally spaced circular grooves 44 are formed in the nozzle distribution area using dry etching or other methods, wherein the axial spacing between adjacent circular grooves 44 is equal. An annular groove is coaxially formed at the bottom of each circular groove 44, simultaneously forming a coaxial circular boss 42. The parallel integrated nozzle chip 4 has electrode bonding grooves etched on both sides of its edges; through holes are formed on the axis of each nozzle by deep silicon etching to form ink flow channels 41; silicon dioxide (SiO2) insulating layers are formed on the upper and lower end faces of the nozzle chip by thermal oxygen growth, and Si3N4 dielectric layers are further formed on the upper and lower end faces by deposition; on the lower end face of the nozzle chip, in an annular area coaxial with the axis of each nozzle, gold / copper material annular extraction electrodes 46 are formed by patterned metal deposition according to design guidelines, and SiO2 passivation layers are formed on the electrode surface by deposition to reduce electrode wear.

[0044] This can be used as a preferred implementation method, such as Figure 2 , Figure 4 , Figure 5 As shown, the assembly method of the entire independently controllable arrayed extraction electrode 46 current fluid nozzle is as follows: First, insert the tail ends of the two ink towers 21 into the ink through holes 14 on both sides of the ink cartridge 1 until the middle sealing partition is in contact with the upper end face of the ink cartridge 1, and seal the gap between the through hole and the tower with glue; connect the ink supply tube 22 to the upper port of the two towers respectively, and seal the gap between the tower and the ink supply tube 22 with epoxy resin glue; vertically install the control circuit board 31 onto the upper end face of the ink cartridge 1, insert the three high voltage electrodes 32 on it into the electrode through holes 13, and seal the joint between the electrode and the through hole with epoxy resin glue. The end cap 11 is installed with its upper surface facing upwards in the shallow end cap groove 16 on the lower surface of the ink cartridge 1, with an interference fit between them; the integrated nozzle chip 4 with the end face of the annular extraction electrode 46 is installed with its lower surface facing downwards on the mounting groove 111 of the end cap 11, and the gap between the ink cartridge 1, the end cap 11 and the integrated nozzle chip 4 is sealed with epoxy resin glue; the flexible flat cable, i.e. the power supply cable 33, is connected from the control circuit board 31 through the two long sides of the ink cartridge 1 to the electrode bonding groove of the integrated nozzle and encapsulated with insulating materials such as rubber or resin; the printhead is installed on the printing platform through the through hole on the protrusion 12 of the ink cartridge 1 by bolts.

[0045] To further explain, such as Figure 6As shown, the working principle of the independently controllable arrayed extraction electrode 46 current fluid printhead is as follows: The ink cartridge 1 is fixed to the shaft of the moving inkjet printing platform using bolts. After the functional ink is prepared, it is injected into the ink tank and ink pump. The ink tubes, ink chamber 15, flow channels, and other structures are cleaned using a solution such as ethanol. After the cleaning solution evaporates, the two ink tubes connected to the ink cartridge 1 via a pagoda are connected to the ink pump and circulating ink tank as the ink inlet and outlet, respectively. The external ink pump is started to expel air from the ink tubes, pagoda, and ink chamber 15. Ink injection is stopped when the air is expelled and the functional ink fills the ink chamber 15 of the ink cartridge 1. Simultaneously, the flow is... The control circuit board 31 sends a high-voltage signal to the high-voltage electrode 32 and the annular extraction electrode 46, causing the ink to become positively charged and form meniscus droplets on the lower end of the ink flow channel 41 and the circular protrusion 42 of each nozzle under the capillary effect. The printing height is controlled. When printing is required, the control circuit board 31 controls the extraction electrode 46 of the corresponding nozzle to switch to low voltage or ground, so that the electric field strength at the nozzle tip is higher than the threshold for printing behavior, thereby causing the corresponding nozzle to eject ink, realizing independent control of the arrayed current fluid printhead and on-demand inkjet printing.

[0046] To achieve the above-mentioned nozzle, the following example is provided: The ink cartridge 1 is manufactured using insulating resin material through injection molding. It has a length of 60,000 μm, a width of 17,000 μm, and a height of 10,000 μm. The protrusion 12 has a side length of 8,000 μm and a height of 8,000 μm, with rounded corners of 1,000 μm on each side. A circular through-hole with a diameter of 3,500 μm is located at the center of its upper end face. Three electrode through-holes 13, each with a diameter of 1,000 μm, are centered at the midpoint of the long axis of the upper end face and 5,000 μm on each side. The length is 6500μm; two recessed ink holes with a diameter of 7000μm and a depth of 1000μm are set 25000μm on both sides of the midpoint of the long central axis on the upper end face, with a diameter of 3000μm and a depth of 8500μm; a rectangular end cap groove with a length of 55000μm, a width of 5000μm and a depth of 500μm is set at the center of the lower end face; a groove with a center distance of 50000μm, a radius of 1500μm and a height of 1500μm is set above the rectangular groove as ink cavity 15.

[0047] The end cap 11 is made of insulating material by injection molding. It is 55,000 μm long, 5,000 μm wide, and 700 μm thick. A groove with a length of 11,000 μm, a width of 5,000 μm, and a depth of 200 μm is provided in the center of the lower end face, which runs horizontally through the middle to accommodate the nozzle chip. A through hole with a length of 9,000 μm, a width of 2,000 μm, and a depth of 500 μm is provided in the center of the upper end face to allow ink to flow smoothly from the ink cavity 15 to the printhead.

[0048] The integrated nozzles are fabricated using a single-crystal silicon wafer through etching and deposition processes. The chip has a side length of 11000μm and a height of 3000μm. Two rows of triangular nozzle arrays with a spacing of 1000μm are arranged on the lower end face, with the row spacing being... μm; for a single nozzle, its ink channel 41 is a through hole with a diameter of 80μm and a length of 200μm; the circular boss 42 is a cylinder with an outer diameter of 120μm and a height of 50μm; the annular groove is an annular groove with an inner diameter of 120μm, an outer diameter of 180μm and a depth of 50μm; the circular groove 44 is a hole with an outer diameter of 180μm and a depth of 100μm; the extraction electrode 46 is a circular metal ring with an inner diameter of 200μm, an outer diameter of 500μm and a thickness of 1μm; the thin film wire 47 is a metal strip with a width of 60μm that extends from the electrode ring to the bonding groove of the opposite electrode.

[0049] In a preferred embodiment of the present invention, after the air purging step is completed, the lower surface inside the integrated nozzle needs to be wiped to keep it dry; then the ink pump is turned on, and at the same time the voltage of 1000V is set to the high voltage electrode 32 and the annular extraction electrode 46 through the control circuit board 31, so that the functional ink is positively charged and fully passes through the ink flow channel 41 through capillary action and forms a meniscus liquid surface on the nozzle protrusion under the action of the electric field; for the printhead that needs to be sprayed, the voltage of its corresponding extraction electrode 46 is set to ground, so that independent control of printing can be achieved, and due to the influence of the electric field concentrated in a small space, the turn-on voltage of the printhead of the present invention is lower than that of a general printhead, and the degree of electric field crosstalk is also lower than that of a general printhead.

[0050] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An independently controllable arrayed extraction electrode electrofluid nozzle, characterized in that, The device includes an ink cartridge, an integrated nozzle chip, an extraction electrode, a thin-film wire, a control circuit board, and a high-voltage electrode. The bottom of the ink cartridge is connected to the integrated nozzle chip, and the bottom of the ink cartridge has an ink outlet. The integrated nozzle chip has multiple nozzle structures arranged in an array corresponding to the ink outlet. The integrated nozzle chip has a groove on the side away from the ink cartridge, and a boss is provided on the bottom of the groove. The height of the boss is less than the depth of the groove, and there is an annular gap between the boss and the inner wall of the groove. An ink flow channel penetrating the integrated nozzle chip is provided in the middle of the boss, thereby forming the nozzle structure. The integrated nozzle chip has an annular extraction electrode on the side of the surface opposite to the ink cartridge surrounding the groove. The extraction electrode is connected to the control circuit board via a thin-film wire. The control circuit board is also connected to the high-voltage electrode, which is inserted into the ink cartridge to apply a high voltage to the ink inside, making the ink positively charged. The control circuit board is used to control the voltage of the extraction electrode to adjust the electric field strength between the electrode and the ink, thereby controlling the printing behavior of the corresponding nozzle structure.

2. The independently controllable arrayed extraction electrode electrofluid nozzle as described in claim 1, characterized in that, The groove is a circular groove, the boss is a circular boss, and the extraction electrode is annular.

3. The independently controllable arrayed extraction electrode electrofluid nozzle as described in claim 1, characterized in that, The multiple nozzle structures are arranged in two rows, and the two rows of nozzle structures are arranged in a triangular array; the extraction electrodes corresponding to the multiple nozzle structures are connected to the control circuit board through multiple thin-film wires distributed on both sides of the nozzle structure and parallel to each other.

4. The independently controllable arrayed extraction electrode electrofluid nozzle as described in claim 1, characterized in that, The integrated nozzle chip has insulating layers formed on both sides of its surface by thermo-oxidative growth, and the surface of the insulating layers is also provided with dielectric layers; the surface of the extraction electrode has a passivation layer formed by deposition.

5. The independently controllable arrayed extraction electrode electrofluid nozzle as described in claim 2, characterized in that, The maximum outer radius of the extraction electrode is determined according to the following formula: ； in, This represents the outer radius of the extraction electrode. This indicates the distance between the axes of adjacent nozzle structures. This indicates the minimum spacing required for adjacent extraction electrodes to undergo electrical breakdown when a preset high voltage and low voltage are applied, respectively.

6. The independently controllable arrayed extraction electrode electrofluid nozzle as described in claim 2, characterized in that, The minimum width of the extraction electrode is determined according to the following formula: ； in, This represents the dimensionless width of the extraction electrode; This represents the dimensionless inner radius of the extraction electrode; This represents the dimensionless height of the extraction electrode from the lower end of the boss; This indicates the outer radius of the boss; , , These represent the outer radius, inner radius, and height from the boss of the extraction electrode, respectively.

7. The independently controllable arrayed extraction electrode electrofluid nozzle as described in claim 6, characterized in that, The minimum threshold electrocoefficient of the extraction electrode voltage used to control the occurrence of printing behavior. for: ； in, The dimensionless electrocapillary coefficient represents the amount of material that is absorbed when the nozzle structure is engaged in printing. The vacuum permittivity, This represents the electric field strength generated between the protrusion and the extraction electrode. This indicates the radius of the ink flow channel. This indicates the surface tension coefficient of the ink used when the nozzle structure is printing.

8. The independently controllable arrayed extraction electrode electrofluid nozzle as described in claim 2, characterized in that, The outer radius of the boss and the height of the extraction electrode from the boss Determined by the following formula: ； in, The minimum electric field strength required to induce jetting behavior. The high voltage applied inside the ink cartridge. To extract the voltage value applied to the electrode.

9. The independently controllable arrayed extraction electrode electrofluid nozzle as described in claim 1, characterized in that, The ink cartridge has an opening at the bottom, and the ink cartridge is detachably connected to the end cap at the bottom opening. The end cap has a mounting groove on the side facing the integrated nozzle chip, and the bottom of the mounting groove has a through ink outlet. The integrated nozzle chip is detachably installed in the mounting groove.

10. The independently controllable arrayed extraction electrode electrofluid nozzle as described in claim 1, characterized in that, It also includes an ink supply system, which includes an ink tower and an ink supply tube. The ink cartridge is provided with an ink through hole. The ink tower is detachably and sealed to the ink through hole. The ink supply tube is used to connect the ink tower and the ink pool. The ink cartridge has a protrusion for connecting to a mobile printing platform.

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