Arrayed electrofluidic jet head addressable jetting device

Abstract

An arrayed electrofluidic jet head addressable jetting device, comprising an arrayed electrofluidic jet head and a high-voltage power supply circuit (2). The arrayed electrofluidic jet head comprises an ink cartridge (11), a nozzle plate (12), nozzles (13) and cross-shaped electrodes (14), the ink cartridge being arranged at the top of the nozzle plate, the ink cartridge being provided with an ink inlet (111) and an ink outlet (112), a plurality of nozzles being uniformly provided on the nozzle plate and being communicated with the ink cartridge, the bottom of the nozzle plate being provided with the cross-shaped electrodes each surrounding the position corresponding to a nozzle, and the high-voltage power supply circuit being electrically connected to each cross-shaped electrode. Each cross-shaped electrode consists of two x electrodes (141) located on the x axis and two y electrodes (142) located on the y axis, each x electrode being a driving electrode for providing a driving force for electrofluidic jetting, and each y electrode being a regulating electrode. By means of regulating the voltage of the y electrodes, the tip electric fields of the nozzles can be controlled, thus achieving addressable jetting. The jetting device has a simple structure, facilitates maintenance and has stable performance.

Description

An arrayed electrofluid nozzle addressable injection device Technical Field

[0001] The present invention relates to the technical field of inkjet printing devices, and in particular to an arrayed electrofluid nozzle addressable injection device. Background Art

[0002] In printed electronics technology, inkjet printing technology is widely used in the fields of micro-nanoelectronic device manufacturing due to its advantages such as convenient printing and low cost. However, with the continuous innovation of technology, the shortcomings of traditional inkjet printing technology in terms of printing accuracy and printing stability are becoming more and more obvious. It is difficult to meet the requirements of large-scale and high-reliability manufacturing of precision electronic components, so electrohydrodynamic printing technology came into being. Compared with traditional inkjet printing technology, electrohydrodynamic printing technology has the following advantages: (1) The droplet size is smaller than the nozzle size, reaching 50 μm, thus achieving high-resolution printing. (2) The liquid selectivity is high. Compared with the traditional 1-20 cP, electrohydrodynamic printing can adapt to liquids of 1-10000 cP. It is precisely because of these advantages that electrohydrodynamic printing technology has been successfully applied to many fields such as photoelectric detection devices, flexible electronic devices, micro electric propulsion, functional protein microarrays, etc.

[0003] To achieve the diverse printing capabilities of arrayed printheads, addressable control of the jetting of arrayed electrofluidic printheads is necessary. Currently, addressable control of jetting in most arrayed electrofluidic printheads is achieved through external electrode rings. However, due to the asymmetry of the electric field, the jet tilts toward the external electrode ring, resulting in jetting failures. Furthermore, since the diameter of the electrode ring is larger than the nozzle diameter, this greatly inconveniences the integration of the printing equipment, as well as the assembly and maintenance of the printhead.

[0004] Patent CN201410289239.5 proposes a method for realizing independently controllable printing of a nozzle, but it requires an extraction electrode to be added in front of the nozzle. The ink is easily deflected onto the extraction electrode, causing damage to the nozzle. In addition, the structure is complex and difficult to manufacture. Patent CN201510299992.7 proposes a miniature electrospray chip device and a manufacturing method, but its spray chip cannot achieve independent regulation of the printing state of each nozzle. Patent CN202111078207.7 proposes an electrofluid nozzle for independently controllable printing, but it has a large limitation on the conductivity of the solution. Summary of the Invention

[0005] The object of the present invention is to overcome the deficiencies of the prior art and provide an arrayed electrofluidic nozzle addressable injection device.

[0006] The technical solutions of the present invention are as follows:

[0007] An arrayed electrofluidic nozzle addressable injection device includes an arrayed electrofluidic nozzle and a high-voltage power supply circuit. The arrayed electrofluidic nozzle includes an ink cartridge, a nozzle plate, a nozzle, and a cross-shaped electrode. The ink cartridge is disposed on top of the nozzle plate and is provided with an ink inlet and an ink outlet. The nozzles are provided in a plurality of uniformly arranged manner on the nozzle plate and communicate with the ink cartridge. A cross-shaped electrode is disposed at the bottom of the nozzle plate corresponding to the position of each nozzle. The high-voltage power supply circuit is electrically connected to each cross-shaped electrode.

[0008] The high-voltage power supply circuit is used to generate two different voltage levels U1 and U2 to generate corresponding voltage levels for each nozzle to spray or not spray, thereby realizing the spray control of each nozzle;

[0009] The cross-shaped electrodes are made of conductive material and are used to apply different voltages to generate an electric field;

[0010] The cross-shaped electrode consists of two x-electrodes located on the x-axis and two y-electrodes located on the y-axis. The x-electrodes are driving electrodes that provide driving force for electrofluid injection, and the y-electrodes are regulating electrodes that control the electric field at the nozzle tip by adjusting the y-electrode voltage, thereby achieving addressable injection.

[0011] Furthermore, the high-voltage power supply circuit is composed of a host computer, a digital main control, a high-voltage power supply, and a multi-way high-voltage switch connected in sequence;

[0012] The host computer is an interface for human-computer interaction, which is used to convert the required printing pattern into printing data and send it to the digital main control, and regulate the output of the high-voltage power supply and the multi-way high-voltage switch through software;

[0013] The digital master is a microcontroller in the form of a single-chip microcomputer or a PLD / FPGA, and is used for receiving, processing, caching, outputting, and timing logic control of printing data. After receiving the required printing data, the digital master converts it into the logic control signals required for the high-voltage power supply and the multi-way voltage switch to operate, and then outputs it serially or in parallel to the high-voltage power supply and the multi-way high-voltage switch according to a given timing sequence;

[0014] The high-voltage power supply is a high-voltage signal generating device, which is used to convert the input low-voltage signal into a high-voltage signal, and is connected to the solution and the cross-shaped electrode through the lead to generate an electric field to drive the solution to spray;

[0015] The multi-way high-voltage switch is a switch in the form of multiple relays or MOS tubes that can withstand high voltage, which is used to receive printing data from the digital master and control the electrode voltage state of each nozzle, thereby controlling the opening and closing of the nozzle.

[0016] Furthermore, the spray hole plate is made of insulating material.

[0017] Furthermore, the orifice plate is obtained by machining through holes on an insulating flat plate or a flat plate with an insulating material interlayer using laser ablation, photoetching, or sandblasting techniques.

[0018] Furthermore, the nozzle plate has a length of 10 mm, a width of 10 mm, and a thickness of 0.5 mm.

[0019] Furthermore, the nozzle is inserted into the through hole of the nozzle plate and bonded using UV curing adhesive.

[0020] Furthermore, the nozzle uses a 34G stainless steel needle with an inner diameter of 60 μm and an outer diameter of 230 μm.

[0021] Furthermore, a Teflon hydrophobic layer is evaporated on the surface of the nozzle.

[0022] Furthermore, the cross-shaped electrode is arranged on the bottom of the nozzle plate by evaporation and pasting.

[0023] Furthermore, the surface of the cross-shaped electrode is covered with an insulating layer.

[0024] Compared to existing technologies, the present invention offers the following advantages: The present invention provides an arrayed electrofluid nozzle addressable injection device. By placing cross-shaped electrodes at the bottom of the nozzle plate corresponding to each nozzle, and applying different voltages to the x and y electrode pairs within the electrodes, the electric field at the corresponding nozzle tip is altered, controlling the nozzle's opening or closing, ultimately achieving addressable, controlled injection from the arrayed electrofluid nozzle. Because the cross-shaped electrodes are located at the nozzle's base, the jet does not tilt onto the electrodes. The present invention offers the advantages of simple structure, ease of maintenance, and stable performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] FIG1 is a schematic structural diagram of an arrayed electrofluidic nozzle addressable injection device provided by the present invention;

[0027] FIG2 is a schematic diagram of the distribution of the cross-shaped electrodes of the present invention;

[0028] FIG3 is a control principle diagram of the cross-shaped electrode according to the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0030] In order to illustrate the technical solution of the present invention, specific embodiments are provided below. Example

[0031] Please refer to Figure 1. This embodiment provides an arrayed electrofluid nozzle addressable injection device, including an arrayed electrofluid nozzle and a high-voltage power supply circuit 2. The arrayed electrofluid nozzle includes an ink cartridge 11, a nozzle plate 12, a nozzle 13 and a cross-shaped electrode 14. The ink cartridge 11 is arranged on the top of the nozzle plate 12. The ink cartridge 11 is provided with an ink inlet 111 and an ink outlet 112. A plurality of nozzles 13 are provided and evenly arranged on the nozzle plate 12 and connected to the ink cartridge 11. The bottom of the nozzle plate 12 is provided with a cross-shaped electrode 14 corresponding to the position of each nozzle 13. The high-voltage power supply circuit is electrically connected to each cross-shaped electrode 14 respectively.

[0032] The orifice plate 12 is a flat plate with holes made of insulating materials such as glass or polymer. Through-holes are machined into the insulating plate or a plate with an insulating material interlayer using laser ablation, photolithography, or sandblasting. The orifice plate 12 made of insulating material helps prevent current transfer between different nozzles, reducing electric field crosstalk and improving addressable control. The orifice plate 12 has a length of 10 mm, a width of 10 mm, and a thickness of 0.5 mm.

[0033] The nozzle 13 is a 34G stainless steel needle with an inner diameter of 60 μm and an outer diameter of 230 μm. The nozzle 13 is inserted into the through hole of the nozzle plate 12 and bonded with UV curing adhesive.

[0034] Preferably, a Teflon hydrophobic layer is evaporated on the surface of the nozzle 13 to prevent ink from spreading.

[0035] The cross-shaped electrode 14 is made of a conductive material and is used to apply different voltages to generate an electric field. It is deposited on the bottom of the nozzle plate 12 by evaporation and bonding, and its surface is covered with an insulating layer. As shown in Figure 2, it consists of two x-electrodes 141 located on the x-axis and two y-electrodes 142 located on the y-axis. The x-electrodes 141 are driving electrodes, providing the driving force for electrofluid injection. The y-electrodes 142 are control electrodes. By adjusting the voltage of the y-electrode 142, the electric field at the tip of the nozzle 13 is controlled, thereby achieving addressable injection.

[0036] The high-voltage power supply circuit 2 is used to generate two different voltage levels U1 and U2 to generate corresponding voltage levels for each nozzle 13 to spray or not spray, thereby realizing the spray control of each nozzle 13. As shown in FIG3 , the high-voltage power supply circuit 2 is composed of a host computer, a digital main control, a high-voltage power supply, and a multi-way high-voltage switch connected in sequence; the host computer is an interface for human-computer interaction, used to convert the pattern to be printed into print data and send it to the digital main control, and to regulate the output of the high-voltage power supply and the multi-way high-voltage switch through software; the digital main control is a microcontroller in the form of a single-chip microcomputer or PLD / FPGA, used for receiving, processing, caching, outputting and timing logic control of print data. After receiving the required print data, the digital main control converts it into the logic control signal required for the high-voltage power supply and the multi-way voltage switch to operate. Then, it is output serially or in parallel to the high-voltage power supply and the multi-way high-voltage switch according to the given timing; the high-voltage power supply is a high-voltage signal generating device, which is used to convert the input low-voltage signal into a high-voltage signal, and is connected to the solution and the cross-shaped electrode through the lead to generate an electric field to drive the solution to spray. Its parameters can be adjusted manually or controlled by the low-voltage signal generated by the digital master; the multi-way high-voltage switch is a switch in the form of multiple relays or MOS tubes that can withstand high voltage, which is used to receive the printing data of the digital master and control the electrode voltage state of each nozzle 13, thereby controlling the opening and closing of the nozzle 13.

[0037] When not spraying, a voltage U1 is applied to the x electrode 141 and the y electrode 142. The surface tension of the solution interface is F y , the electric field force F exerted on the solution at the tip of nozzle 13 E1 , at this time F y >F E1 , the nozzle 13 does not spray. When the nozzle 13 is turned on, the voltage of the y electrode 142 is increased to U2 (U2>U1), the electric field at the tip of the nozzle 13 corresponding to the cross-shaped electrode 14 is enhanced, and the electric field force on the solution at the tip of the nozzle 13 increases to F E2 , at this time F y <F E2 , the nozzle 13 produces spraying.

[0038] During normal spraying, the surface tension coefficient of the solution is y0. N The surface tension of the solution interface is F y =4y0 / d N At this time, the same working voltage U1 is applied to the x-electrode 141 and the y-electrode 142 in each group of cross-shaped electrodes 14, and the electric field force on the solution at the tip of the nozzle 13 is , where E1 is the electric field strength between the nozzle 13 and the printing substrate. y >F E1, all nozzles 13 do not spray. Increase the voltage of the y electrode 142 to U2 (U2>U1), and the voltage of the x electrode 141 remains unchanged. At this time, the electric field at the tip of the corresponding nozzle 13 is enhanced, and the electric field strength rises to E2. The electric field force on the solution at the tip of the nozzle 13 also rises to F E2 , F y0 <F E2， The nozzle 13 is opened to spray the solution.

[0039] A personal computer PC is selected as the host computer, and a single-chip microcomputer is selected as the digital main control. Before using the arrayed electrofluid nozzle, first align the mounting hole on the ink cartridge 11 with the threaded hole on the experimental platform, fix the arrayed electrofluid nozzle on the experimental platform with bolts, and adjust the arrayed electrofluid nozzle fixture to keep the nozzle 13 parallel to the printing substrate to ensure that each nozzle 13 is subjected to the same magnitude of electric field force. Then use a flow pump to pump in the ethanol solution from the ink inlet 111, and discharge the bubbles in the ink cartridge 11 from the ink outlet 112. When the ethanol solution fills the ink cartridge 11, the printing height is controlled to be 1mm, and the ambient temperature is 20°C, then the opening voltage of the nozzle 13 is about 900V.

[0040] When the arrayed electrofluid nozzle is in use, a signal is output to the single-chip microcomputer through the personal computer PC. The single-chip microcomputer sends the signal to the high-voltage power supply and the multi-way high-voltage switch to control the on and off of the high-voltage power supply and the multi-way high-voltage switch, and then controls the voltage state of each electrode. First, 800V is applied to the x electrode 141 and the y electrode 142 in the cross-shaped electrode. The electric field force on the liquid is less than the surface tension on the liquid, and all nozzles 13 do not spray. At this time, for the nozzle 13 to be turned on, the voltage of its corresponding y electrode 142 is changed to 1200V, and the voltage of the x electrode 141 remains unchanged, so that the electric field strength between the nozzle 13 and the printing substrate increases, the electric field force on the liquid is greater than the surface tension on the liquid, and the nozzle 13 starts to spray. When the nozzle 13 needs to stop spraying again, the voltage of the y electrode 142 is changed back to 800V, and the rest remain unchanged, and the nozzle 13 stops spraying. By controlling different nozzles 13 to spray in sequence, patterned printing is completed.

[0041] The above are only preferred embodiments of the present invention and are 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 in the scope of protection of the present invention.

Claims

1. An arrayed electrofluid nozzle addressable injection device, characterized in that: The invention comprises an arrayed electrofluid nozzle and a high-voltage power supply circuit, wherein the arrayed electrofluid nozzle comprises an ink cartridge, an orifice plate, a nozzle and a cross-shaped electrode, wherein the ink cartridge is arranged on the top of the orifice plate, an ink inlet and an ink outlet are arranged on the ink cartridge, a plurality of nozzles are arranged evenly on the orifice plate and are connected to the ink cartridge, a cross-shaped electrode is arranged around the bottom of the orifice plate corresponding to the position of each nozzle, and the high-voltage power supply circuit is electrically connected to each cross-shaped electrode respectively; The high-voltage power supply circuit is used to generate two different voltages U1 and U2 to generate corresponding voltage levels for each nozzle to spray or not spray, thereby realizing spray control of each nozzle; The cross-shaped electrode is a conductive material and is used to apply different voltages to generate an electric field; The cross-shaped electrode consists of two x electrodes located on the x-axis and two y electrodes located on the y-axis. The x-electrodes are driving electrodes that provide driving force for electrofluid injection, and the y-electrodes are regulating electrodes that control the electric field at the nozzle tip by adjusting the y-electrode voltage, thereby achieving addressable injection.

2. The arrayed electrofluid nozzle addressable injection device according to claim 1, characterized in that: The high-voltage power supply circuit is composed of a host computer, a digital main control, a high-voltage power supply, and a multi-channel high-voltage switch connected in sequence; The host computer is an interface for human-computer interaction, which is used to convert the required printed pattern into printing data and send it to the digital main control, and regulate the output of the high-voltage power supply and the multi-channel high-voltage switch through software; The digital master control is a microcontroller in the form of a single chip or PLD / FPGA, which is used for receiving, processing, caching, outputting and timing logic control of printing data. After receiving the required printing data, the digital master control converts it into the logic control signal required for the high-voltage power supply and the multi-channel voltage switch action, and then outputs it to the high-voltage power supply and the multi-channel high-voltage switch in series or in parallel according to a given timing sequence; The high-voltage power supply is a high-voltage signal generating device, which is used to convert the input low-voltage signal into a high-voltage signal, and is connected to the solution and the cross-shaped electrode through the lead wire to generate an electric field to drive the solution to spray; The multi-channel high-voltage switch is a switch in the form of multiple relays or MOS tubes that can withstand high voltage, and is used to receive printing data from a digital master control and control the electrode voltage state of each nozzle, thereby controlling the opening and closing of the nozzle.

3. The arrayed electrofluid nozzle addressable injection device according to claim 1, characterized in that: The spray hole plate is made of insulating material.

4. The arrayed electrofluid nozzle addressable injection device according to claim 3, characterized in that: The spray hole plate is obtained by processing through holes on an insulating flat plate or a flat plate with an insulating material interlayer using laser ablation, photoetching, and sandblasting techniques.

5. The arrayed electrofluid nozzle addressable injection device according to claim 4, characterized in that: The orifice plate has a length of 10 mm, a width of 10 mm, and a thickness of 0.5 mm.

6. The arrayed electrofluid nozzle addressable injection device according to claim 4, characterized in that: The nozzle is inserted into the through hole of the orifice plate and bonded using UV curing adhesive.

7. The arrayed electrofluid nozzle addressable injection device according to claim 6, characterized in that: The nozzle adopts a stainless steel 34G needle with an inner diameter of 60 μm and an outer diameter of 230 μm.

8. The arrayed electrofluid nozzle addressable injection device according to claim 7, characterized in that: A Teflon hydrophobic layer is evaporated on the surface of the nozzle.

9. The arrayed electrofluid nozzle addressable injection device according to claim 1, characterized in that: The cross-shaped electrode is arranged on the bottom of the spray hole plate by evaporation and bonding.

10. An arrayed electrofluid nozzle addressable injection device according to claim 1 or 9, characterized in that: The surface of the cross-shaped electrode is covered with an insulating layer.

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