Ink-jet printing head integrated structure based on microfluidics

Abstract

The invention relates to an ink-jet printing head integrated structure based on microfluidics, and belongs to the technical field of microfluidics. The device comprises an ink supply device, a micro-fluidic chip and an ink-jet printing head, the micro-fluidic chip is internally provided with a group of micro-channels and an active control element, the active control element controls the size, the shape and the speed of liquid drops in the micro-channels, the ink supply end of the ink supply device is connected with the inlet end of the micro-channels of the micro-fluidic chip, and the ink-jet printing head is connected with the micro-channels of the micro-fluidic chip. A micro-channel outlet end of the micro-fluidic chip is connected with an ink-jet printing head, the ink-jet printing head is internally provided with nozzles which are correspondingly communicated with the micro-channel outlet end in a one-to-one mode, and a movable substrate is arranged in the ink-jet direction of the nozzles. The micro-fluidic chip and the ink-jet printing head are integrally arranged, liquid drops are accurately regulated and controlled through the micro-fluidic chip, accurate sorting and conveying of the liquid drops are achieved, controllable printing of the liquid drops is achieved through the ink-jet printing head, and the printing quality and efficiency are improved.

Description

Technical Field

[0001] This invention relates to the field of microfluidic control technology, and more specifically to an integrated structure for an inkjet printhead based on microfluidics. Background Technology

[0002] Microfluidics is a technology that manipulates fluids at the micrometer / submicrometer scale, offering advantages such as high precision, high integration, and low power consumption. In recent years, with the continuous development of micro / nano manufacturing technology, microfluidics has been widely applied in fields such as biology, chemistry, and medicine. Inkjet printing, on the other hand, is a non-contact printing method that achieves high-resolution image and text printing by ejecting ink in the form of tiny droplets onto a medium. Traditional inkjet printing technologies typically rely on thermal bubbles or piezoelectric actuation mechanisms to generate ink droplets. Thermal inkjet printing uses heated ink to create bubbles that propel droplets, while piezoelectric inkjet printing utilizes the deformation of piezoelectric materials to control droplet release. These methods suffer from problems in practical applications, including nozzle clogging, poor droplet size consistency, high power consumption, and limited printing resolution. Especially during prolonged continuous operation, ink evaporation or residue accumulation can lead to performance degradation, affecting print quality and equipment lifespan. Furthermore, traditional technologies lack sufficient control over ink fluid dynamics, making it difficult to achieve micrometer-level droplet positioning, thus limiting their application potential in fields such as biomedicine and high-precision pattern printing. Summary of the Invention

[0003] This invention aims to overcome the shortcomings of existing technologies by providing a microfluidic-based integrated inkjet printhead structure to solve the problems existing in traditional inkjet printheads during droplet sorting, transport, and printing, thereby improving print quality and efficiency.

[0004] It adopts the following technical solution: An integrated structure for an inkjet printhead based on microfluidics includes an ink supply unit, a microfluidic chip, and an inkjet printhead. The microfluidic chip has a set of microchannels and active control elements. The active control elements control the size, shape, and velocity of droplets in the microchannels. The ink supply end of the ink supply unit is connected to the inlet end of the microchannels of the microfluidic chip. The outlet end of the microchannels of the microfluidic chip is connected to the inkjet printhead. The inkjet printhead has nozzles that are connected to the outlet ends of the microchannels one by one. A movable substrate is provided in the inkjet direction of the nozzles.

[0005] Furthermore, the active control element is a piezoelectric actuator or a thermoelectric valve.

[0006] Furthermore, the inkjet printhead is an integrated thermally energized or micro-piezoelectric printhead.

[0007] Furthermore, the microfluidic chip is connected to an external control system via an integrated electronic interface.

[0008] Furthermore, the microchannel has a trapezoidal or triangular cross-section.

[0009] Furthermore, the inner wall of the microchannel is provided with a hydrophobic layer.

[0010] The advantages of this invention compared to the prior art are as follows: This invention integrates a microfluidic chip with an inkjet printhead. The microfluidic chip precisely controls the droplets, enabling accurate sorting and transport of the droplets. The inkjet printhead then enables controllable printing of the droplets, improving print quality and efficiency. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of an integrated structure of an inkjet printhead based on microfluidics according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the microchannel in an embodiment of the present invention.

[0012] Explanation of reference numerals in the attached figures: 100, ink supply unit; 200, microfluidic chip; 201, microchannel; 202, active control element; 203, hydrophobic layer; 300, inkjet printhead; 301, nozzle; 400, substrate; 500, external control system. Detailed Implementation

[0013] To make the present invention clearer, the following description, in conjunction with the accompanying drawings, further illustrates an integrated structure of an inkjet printhead based on microfluidics. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0014] like Figure 1 As shown, an integrated structure of an inkjet printhead based on microfluidics includes an ink supply unit 100, a microfluidic chip 200, and an inkjet printhead 300. The microfluidic chip 200 has a set of microchannels 201 and an active control element 202. The ink supply end of the ink supply unit 100 is connected to the inlet end of the microchannel 201 of the microfluidic chip 200, and the inkjet printhead 300 is connected to the outlet end of the microchannel 201 of the microfluidic chip 200. The inkjet printhead 300 has nozzles 301 that are connected to the outlet end of the microchannel 201 one by one. A controllably movable substrate 400 is provided in the inkjet direction of the nozzles 301.

[0015] The active control element 202 controls the size, shape, and velocity of droplets in the microchannel 201. In this embodiment, the active control element 202 is a piezoelectric actuator or a thermoelectric valve. By adjusting the fluid pressure, electric field, or temperature field, it achieves dynamic control of the droplet size, shape, and velocity, ensuring droplet uniformity and stability during sorting and transport. The microchannel 201 in the microfluidic chip 200 is a multi-channel parallel processing system, adaptable to inks of different viscosities and complex fluids containing solid particles. The size, shape, and velocity of each droplet can be effectively controlled, ensuring droplet consistency and stability during printing.

[0016] Specifically, the microfluidic chip 200 is connected to an external control system 500 via an integrated electronic interface. The external control system 500 is a computer or microcontroller. The external control system 500 sends digital signal command signals to the microfluidic chip 200. These signals are transmitted via standard communication protocols (such as SPI or I2C) to specify the size, type, and arrangement sequence of the droplets. Upon receiving the command, the microfluidic chip 200 uses a built-in active control element 202 (such as a piezoelectric actuator or a thermal bubble valve) to precisely regulate the fluid behavior within the microchannel 201: the piezoelectric actuator deforms in response to voltage changes, or the thermal bubble valve forms vapor bubbles through local heating, dynamically adjusting the channel opening and closing state and fluid pressure; by controlling the channel opening and closing actions in a timing sequence, the microfluidic chip 200 divides the continuous fluid into discrete droplets and generates droplets in the order specified by the command, ensuring that the droplets form a strict sequence in the transmission path. At the same time, combined with the auxiliary adjustment of the electric field or temperature field, the droplet spacing and stability are maintained. The arranged droplets are then precisely guided to the inkjet printhead through the microchannel 201.

[0017] Among them, combined Figure 2 As shown, the microchannel 201 employs an optimized geometric design, such as a trapezoidal or triangular cross-section. Its inner wall is provided with a hydrophobic layer 203, thereby reducing fluid resistance and eddies, ensuring that droplets maintain a predetermined trajectory during transport. An active control element 202 is integrated within the channel, which, through time-sequential regulation of the fluid pressure gradient, propels the droplets to flow at a constant speed. Simultaneously, an electric field or temperature gradient field is used to further stabilize the droplet spacing and suppress merging or diffusion. The outlet of the microchannel 201 is precisely aligned with the nozzles of the inkjet printhead 300, achieving seamless connection through a standardized interface (such as a microfluidic coupler), ensuring droplet injection into the nozzle without damage, maintaining consistency in size, shape, and sequence, and adapting to high-resolution printing requirements.

[0018] After receiving droplets, the inkjet printhead 300 uses its own printing mechanism to precisely spray the droplets onto the substrate 400 to be printed, realizing a microfluidic inkjet printhead integrated chip. In this embodiment, the inkjet printhead 300 is a conventional integrated thermal foaming or micro piezoelectric printhead.

[0019] When this structure is in operation, the ink supply unit 100 stores and stably supplies ink to the microfluidic chip 200, ensuring that the ink flow is controllable and free from bubble interference. The microfluidic chip 200 performs precise sorting and droplet formation of ink through the internal microchannel 201, achieving optimized control of single droplet size and frequency. The inkjet printhead 300 applies thermal pulse or voltage pulse drive signals to instantaneously pressurize and eject the sorted droplets at high speed, which fall through the nozzle orifice to the designated position on the substrate 400 to be printed with micron-level precision, ultimately forming a highly reliable and low-energy integrated printing system.

[0020] The above embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. However, obvious variations or modifications derived from the essential spirit of the present invention still fall within the protection scope of the present invention.

Claims

1. A microfluidic-based inkjet printhead integrated structure, characterized in that: The device includes an ink supply unit (100), a microfluidic chip (200), and an inkjet printhead (300). The microfluidic chip (200) has a set of microchannels (201) and an active control element (202). The active control element (202) controls the size, shape, and speed of droplets in the microchannels (201). The ink supply end of the ink supply unit (100) is connected to the inlet end of the microchannels (201) of the microfluidic chip (200). The outlet end of the microchannels (201) of the microfluidic chip (200) is connected to the inkjet printhead (300). The inkjet printhead (300) has nozzles (301) that are connected one-to-one with the outlet end of the microchannels (201). The nozzles (301) have movable substrates (400) in the inkjet direction.

2. The integrated structure of an inkjet printhead based on microfluidics according to claim 1, characterized in that: The active control element (202) is a piezoelectric actuator or a thermoelectric valve.

3. The integrated structure of an inkjet printhead based on microfluidics according to claim 1, characterized in that: The inkjet printhead (300) is an integrated thermally energized or micro-piezoelectric printhead.

4. The integrated structure of an inkjet printhead based on microfluidics according to claim 1, characterized in that: The microfluidic chip (200) is connected to an external control system (500) via an integrated electronic interface.

5. The integrated structure of an inkjet printhead based on microfluidics according to claim 1, characterized in that: The microchannel (201) has a trapezoidal or triangular cross-section.

6. The integrated structure of an inkjet printhead based on microfluidics according to claim 5, characterized in that: The inner wall of the microchannel (201) is provided with a hydrophobic layer (203).

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