A printhead comprising internal microfluidic channels

Abstract

This invention provides a printhead with an internal microfluidic channel. The printhead includes a print base and a print chip. The print base includes an inlet channel, an outlet channel, and a storage tank, which are interconnected. The print chip is encapsulated on the surface of the print base and is connected to the storage tank to form the internal microfluidic channel. The capacity of the internal microfluidic channel is equal to the amount of printing liquid loaded into the printhead at one time. The printhead of this invention, through the internal microfluidic channel, allows old printing liquid to be ejected in one go, greatly reducing the probability of printing liquid contamination and solving the problem of difficult printing liquid discharge. Furthermore, the internal microfluidic channel with its small capacity significantly reduces the cost of using printing liquid. The inlet and outlet channels, with their small cross-sectional area, form a unidirectional flow path. Due to the high pressure and fast flow rate within the unidirectional flow path, the discharge rate can be improved.

Description

Technical Field

[0001] This invention relates to the field of bioprinting devices, and in particular to a printhead containing internal microchannels. Background Technology

[0002] Bioprinting refers to the process of printing biological materials (including natural, synthetic, or cell solutions) into designed three-dimensional structures using the principles and methods of 3D printing. Bioprinting technology differs from ordinary 3D printing in that the biological tissues or organs it produces possess certain biological functions, providing conditions for further cell and tissue growth. Due to these characteristics, bioprinting technology faces many specific technical challenges in its development. Among these challenges, the technology that uses cells as printing materials is called cell 3D printing. This involves using cells and biocompatible materials to create bio-ink, moving a nozzle to eject the bio-ink, and controlling the nozzle's movement through a program to print the bio-ink according to a preset target, thus shaping the object into a three-dimensional digital model.

[0003] Existing printers used for bioprinting, including extrusion and non-contact printers, use an open printhead design, as shown in the attached figure. Figure 1 As shown, the liquid inlet on the printhead is an open inlet, which makes it convenient to add liquid into the open inlet using a pipette. However, the problem with the open printhead is that the cell solution will settle over time due to gravity. After the cell solution settles, it needs to be manually aspirated. This operation requires a high level of skill from the operator, is labor-intensive and time-consuming. In addition, because the size of the open inlet inside the printhead is very small, it is difficult for the pipette to completely aspirate all the liquid, making the cell solution easily contaminated.

[0004] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a printhead containing internal microchannels to solve the problem in the prior art where open printheads are used, and the cell solution is difficult to drain after settling due to gravity over time, leading to easy contamination of the cell solution.

[0006] To achieve the above and other related objectives, the present invention provides a printhead comprising internal microchannels, the printhead comprising:

[0007] A printing base, the printing base including a liquid inlet channel, a liquid outlet channel and a storage tank, wherein the liquid inlet channel and the liquid outlet channel are in communication with the storage tank;

[0008] A printing chip is encapsulated on the surface of the printing base, and the printing chip is connected to the storage tank to form an internal microchannel, and the accommodating space of the internal microchannel is equal to the amount of liquid filled by the print head in one printing operation.

[0009] Preferably, the printing base further includes a waste liquid tank connected to the liquid outlet channel, and the waste liquid tank and the printing chip are disposed on opposite sides of the printing base.

[0010] Preferably, the inlet channel is located outside the waste liquid tank, and the outlet channel is located inside the waste liquid tank.

[0011] Preferably, the internal microchannel has a capacity of 10 μL to 30 μL.

[0012] Preferably, the printing chip is rectangular in shape and includes a first surface and a second surface disposed opposite to each other. The first surface has a chip liquid inlet along its length, which is connected to the internal microchannel. The second surface has a plurality of nozzles, which are arranged in a row at equal intervals along its length and are all connected to the printing chip liquid inlet. The printing liquid in the internal microchannel enters the nozzles through the chip liquid inlet.

[0013] Preferably, the printing chip is a thermal inkjet printing chip.

[0014] Preferably, the liquid inlet channel has a circular liquid inlet with a diameter of 0.5 mm to 1.5 mm.

[0015] Preferably, the inlet channel is connected to a pipette for manual liquid addition, or the inlet channel is connected to a liquid supply line, the liquid supply line being electrically connected to a controller, the controller being used to control the liquid supply line to automatically add liquid to the inlet channel.

[0016] Preferably, the liquid inlet channel has a funnel-shaped liquid inlet that is cylindrical at the top and conical at the bottom.

[0017] Preferably, the inlet channel is connected to a pipette for manual liquid addition.

[0018] As described above, the printhead containing internal microchannels of the present invention has the following beneficial effects:

[0019] The printhead in this invention forms an internal microchannel by connecting the print chip and the storage tank. The capacity of the internal microchannel is equal to the amount of printing liquid loaded into the printhead at one time. This allows the old printing liquid to be ejected all at once during the liquid discharge operation, greatly reducing the probability of printing liquid contamination and solving the problem of printing liquid being difficult to discharge from the print base. Furthermore, the internal microchannel structure with its small capacity does not cause waste of printing liquid and can greatly save on the cost of using printing liquid.

[0020] In this invention, the inlet channel is connected to a pipette or a supply line for manual or automatic liquid addition, thus forming a unidirectional flow path between the inlet and outlet channels. After the first addition of printing liquid, the printer begins printing. After a certain period of time, the printing liquid (such as cell solution) in the print head begins to settle, failing to meet printing requirements. When new printing liquid is added again, a unidirectional flow path is formed between the inlet and outlet channels, which have a smaller cross-sectional area. Due to the high pressure and fast flow rate within the unidirectional flow path, the discharge rate can be improved. This invention also solves the problems of existing technologies using open inlet print heads, where cell solution settles over time due to gravity, and the need for manual removal of settled cell solution using a pipette, which is labor-intensive and time-consuming. Furthermore, the small size of the open inlet makes it difficult to completely remove all the liquid, leading to easy contamination of the cell solution. Attached Figure Description

[0021] Figure 1 The diagram shows a three-dimensional structure of a printed substrate in the prior art.

[0022] Figure 2 The diagram shown is a three-dimensional structural schematic of the printing substrate in Embodiment 1 of the present invention.

[0023] Figure 3 Displayed as Figure 2 A schematic diagram of the cross-sectional structure along the AA direction.

[0024] Figure 4 The diagram shown is a front view of the printing substrate in Embodiment 1 of the present invention.

[0025] Figure 5 The diagram shown is a top view of the printed substrate in Embodiment 1 of the present invention.

[0026] Figure 6 The diagram shown is a bottom view of the printed substrate in Embodiment 1 of the present invention.

[0027] Figure 7 The diagram shown is a three-dimensional structural schematic of the chip from a first-view perspective in this invention.

[0028] Figure 8 The diagram shown is a three-dimensional structural schematic of the chip from a second perspective in this invention.

[0029] Figure 9 The diagram shown is a three-dimensional structural schematic of the printing substrate in Embodiment 2 of the present invention.

[0030] Figure 10 Displayed as Figure 9 A schematic diagram of the cross-sectional structure along the BB direction.

[0031] Figure 11 The diagram shown is a front view of the printed substrate in Embodiment 2 of the present invention.

[0032] Component designation explanation

[0033] 100a Open Inlet

[0034] 100, 110 Liquid Inlet Channels

[0035] 200 liquid outlet channels

[0036] 300 storage slots

[0037] 400 Waste Liquid Tank

[0038] 500 Printed Chips

[0039] 600 chip liquid inlet

[0040] 700 nozzles Detailed Implementation

[0041] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0042] Please see Figures 2 to 11 It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0043] Example 1

[0044] Please refer to Figures 2 to 8This embodiment provides a printhead including internal microchannels, the printhead comprising at least:

[0045] The printing base includes an inlet channel 100, an outlet channel 200, and a storage tank 300, with the inlet channel 100 and outlet channel 200 communicating with the storage tank 300.

[0046] The printing chip 500 is encapsulated on the surface of the printing base, and the printing chip 500 is connected to the storage tank 300 to form an internal microchannel. The capacity of the internal microchannel is equal to the amount of liquid filled by the print head in one printing cycle.

[0047] Specifically, by configuring the inlet channel 100, outlet channel 200, and storage tank 300 within the print base, the print chip 500, connected to the storage tank 300, can form an internal microchannel with the print base. This internal microchannel can store print liquid. When print liquid is first added to the print head and the printer performs printing for a certain period, the print liquid inside the print head begins to settle (like cells in a cell solution). When the print liquid is insufficient for printing, a liquid adding device, such as a pipette, connected to the inlet channel 100, can add new print liquid to the internal microchannel. Since the capacity of the internal microchannel is equal to the amount of print liquid loaded into the print head at one time, the old print liquid is pushed out through the outlet channel 200 after the new print liquid is added, thus discharging waste liquid. This embodiment solves the problem of print liquid, especially cell solutions, settling over time due to gravity and being difficult to drain from the print base, thereby improving print quality.

[0048] In a specific embodiment of the present invention, the printing base also includes a waste liquid tank 400 connected to the liquid outlet channel 200, and the waste liquid tank 400 and the printing chip 500 are respectively disposed on opposite sides of the printing base.

[0049] Specifically, such as Figure 5 The waste liquid tank 400 is located on the surface of the printing base, that is, the waste liquid tank 400 and the printing chip 500 are respectively located on opposite sides of the printing base. The waste liquid tank 400 is used to contain the waste liquid discharged from the liquid outlet channel 200, so as to facilitate the treatment of the waste liquid. However, it is not limited to this. The liquid outlet channel 200 can also be directly connected to the drain pipe for waste liquid collection, etc., which will not be elaborated here.

[0050] In a specific embodiment of the present invention, the inlet channel 100 is located outside the waste liquid tank 400, and the outlet channel 200 is located inside the waste liquid tank 400. This keeps the inlet channel 100 away from the waste liquid tank 400, thus avoiding contamination of the inlet channel 100.

[0051] Specifically, such as Figures 2-4As shown, in this embodiment, the inlet end face of the liquid inlet channel 100 is not lower than the outlet end face of the liquid outlet channel 200, and the liquid inlet channel 100 and the liquid outlet channel 200 are on the same horizontal line in the horizontal direction. The outlet end face of the liquid outlet channel 200 is not higher than the opening end of the waste liquid tank 400, and the inlet end face of the liquid outlet channel 200 is flush with the bottom of the waste liquid tank 400; the outlet end face of the liquid inlet channel 100 is flush with the bottom of the waste liquid tank 400, so that the liquid inlet channel 100 with a higher inlet end face can avoid contamination caused by liquid backflow, but the positional relationship between the liquid outlet channel 200 and the liquid inlet channel 100 is not limited to this.

[0052] In a specific embodiment of the present invention, the accommodating space of the internal microchannel is 10μL to 30μL (e.g., 10μL, 15μL, 20μL, 25μL, 30μL). Specifically, due to the small depth of the waste liquid tank 400, the internal microchannel formed by the waste liquid tank 400 and the printing chip 500 can only store about 10μL to 30μL of printing liquid. Printing liquids (such as cell solutions) are usually quite expensive, and cell solutions tend to settle due to their own gravity. If a large amount of cell solution is added at once, it will result in waste of printing liquid. 10μL to 30μL of printing liquid is the amount of printing liquid filled by the print head in one operation. Therefore, the internal microchannel design can greatly save the cost of using printing liquid.

[0053] In a specific embodiment of the present invention, such as Figure 7 , Figure 8 As shown, the printing chip 500 is rectangular in shape and includes a first surface and a second surface arranged opposite each other. The first surface has a liquid inlet 600 along its length, which communicates with the internal microchannels. The second surface has multiple nozzles 700, which are arranged in a row at equal intervals along the length, and all nozzles 700 are connected to the liquid inlet 600. The printing liquid in the internal microchannels enters the nozzles 700 through the liquid inlet 600. The specific shape of the printing chip 500 is not excessively limited here.

[0054] In a specific embodiment of the present invention, the printing chip 500 is a thermal inkjet printing chip.

[0055] Specifically, in this embodiment, the printing chip 500 is a silicon-based thermal inkjet printing chip. The thermal inkjet printhead uses thermal inkjet printing technology, which heats the printhead to generate ink bubbles, which are then sprayed onto the printing medium. This is a high-temperature, high-pressure printing technology. Its working principle is as follows: Under normal conditions, the ink inside the printhead achieves a relative equilibrium with the external atmospheric pressure under the influence of surface tension, remaining in a stable state. When the printhead receives a printing signal, the heating element inside the printhead (e.g., a thin-film resistor) rapidly heats up, causing the ink near the heating element to rise sharply and vaporize, forming countless tiny bubbles. These small bubbles aggregate and grow to form a vapor film. When the printing signal disappears, the residual heat from the heating element causes the bubbles to expand further. The internal pressure forces the ink out of the nozzle, while the temperature of the heating element begins to drop. As the surface temperature of the heating element decreases, the boundary between the bubbles and the ink begins to cool. Since the ink tip has been squeezed out of the nozzle, and the ink shrinks at the rear, the internal pressure of the printhead decreases, creating a negative pressure at the nozzle, which then draws the ink back into the printhead. After the air bubbles inside the printhead disappear, the negative pressure continues to act, completely separating the ink droplets from the nozzle, and the remaining ink is drawn back into the printhead. Then, surface tension generates an outward suction force, drawing new ink to replenish the ink ejection area in preparation for the next printing cycle. Thus, during the waste liquid removal operation of the printhead, the print chip 500 and the print base form a closed receiving space, allowing ink to enter through the inlet of the inlet channel 100 and exit through the outlet of the outlet channel 200.

[0056] In a specific embodiment of the present invention, the liquid inlet channel 100 is a circular liquid inlet with a diameter of 0.5 mm to 1.5 mm (e.g., 0.5 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.5 mm).

[0057] In a specific embodiment of the present invention, the liquid inlet channel 100 is connected to a pipette (unmarked) for manual liquid addition, or the liquid inlet channel 100 is connected to a liquid supply line (unmarked), and the liquid supply line is electrically connected to a controller (unmarked), which controls the liquid supply line to automatically add liquid to the liquid inlet channel 100.

[0058] Specifically, such as Figure 2 The diagram shows a three-dimensional structure of the printhead base. The liquid inlet channel 100 is a circular inlet with threads along its circumference. When the pipette or the liquid supply line is connected to the liquid inlet channel 100, the sealing performance is relatively good. When the pipette is manually filled or the liquid supply line is automatically filled, the pressure increases, forming a unidirectional flow path between the liquid inlet channel 100 and the liquid outlet channel 200, thus discharging the old printing liquid in one go.

[0059] Example 2

[0060] Please refer to Figures 7 to 11This embodiment also provides a printhead containing internal microchannels. The main difference between this embodiment and embodiment 1 is the morphology of the liquid inlet of the liquid inlet channel 110. For the specific structure of the printhead, please refer to embodiment 1, which will not be repeated here. The following only introduces the differences from embodiment 1.

[0061] In a specific embodiment of the present invention, the liquid inlet channel 110 has a funnel-shaped liquid inlet that is cylindrical at the top and conical at the bottom.

[0062] In a specific embodiment of the present invention, the liquid inlet channel 110 is connected to a pipette (not labeled) for manual liquid addition.

[0063] Specifically, such as Figure 10 , Figure 11 As shown, the inlet of the liquid inlet channel 110 is located at the bottom of the cone-shaped funnel, meaning the inlet of the liquid inlet channel 110 is lower than the outlet of the liquid outlet channel 200, and the liquid inlet channel 110 and the liquid outlet channel 200 are on the same horizontal line. This arrangement makes it easier for the pipette tip to be aligned with the inlet port, and improves the sealing between the liquid inlet channel 110 and the pipette. When manually adding liquid using the pipette, a unidirectional flow path is formed between the liquid inlet channel 110 and the liquid outlet channel 200. After the first addition of printing liquid, the printer starts printing. After a certain period of time, the printing liquid (such as cell solution) in the print head begins to settle and can no longer meet the printing requirements. When new printing liquid is added again, the old printing liquid is pushed out of the liquid outlet channel 200 and directly into the waste liquid tank 400.

[0064] In summary, the printhead of this invention forms an internal microchannel by connecting the print chip and the storage tank. The capacity of the internal microchannel is equal to the amount of printing liquid loaded into the printhead at one time. This allows the old printing liquid to be expelled all at once during the liquid discharge operation, greatly reducing the probability of printing liquid contamination and solving the problem of printing liquid being difficult to discharge from the print base. Furthermore, the internal microchannel structure with its small capacity does not cause waste of printing liquid, thus significantly saving on the cost of using printing liquid.

[0065] In this invention, the inlet channel is connected to a pipette or supply line for manual or automatic liquid addition, thus forming a unidirectional flow path between the inlet and outlet channels. After the first addition of printing liquid, the printer begins printing. After a certain period, the printing liquid (e.g., cell solution) in the printhead begins to settle, failing to meet printing requirements. When new printing liquid is added again, the inlet and outlet channels, with their smaller cross-sectional area, form a unidirectional flow path. Due to the high pressure and fast flow rate within this unidirectional path, the discharge rate is improved. This invention also solves the problems of existing open-inlet printheads, where cell solution settles over time due to gravity, requiring manual removal of settled cell solution with a pipette – a labor-intensive and time-consuming process. Furthermore, the small size of the open inlet makes it difficult to completely remove all liquid, leading to cell solution contamination. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial applicability.

[0066] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A printhead comprising internal microchannels, characterized in that, The printhead includes: A printing base includes a liquid inlet channel, a liquid outlet channel, and a storage tank, wherein the liquid inlet channel and the liquid outlet channel are in communication with the storage tank; the liquid inlet channel has a circular inlet with a diameter of 0.5 mm to 1.5 mm; the liquid inlet channel is connected to a pipette for manual liquid addition, or the liquid inlet channel is connected to a liquid supply line, the liquid supply line being electrically connected to a controller, the controller being used to control the liquid supply line to automatically add liquid to the liquid inlet channel; and a unidirectional flow path is formed between the liquid inlet channel and the liquid outlet channel; A printing chip is encapsulated on the surface of the printing base, and the printing chip is connected to the storage tank to form an internal microchannel, and the accommodating space of the internal microchannel is equal to the amount of liquid filled by the print head in one printing operation.

2. The printhead comprising internal microchannels according to claim 1, characterized in that, The printing base also includes a waste liquid tank connected to the liquid outlet channel, and the waste liquid tank and the printing chip are respectively disposed on opposite sides of the printing base.

3. The printhead comprising internal microchannels according to claim 2, characterized in that, The inlet channel is located outside the waste liquid tank, and the outlet channel is located inside the waste liquid tank.

4. The printhead comprising internal microchannels according to claim 1, characterized in that, The internal microchannel has a capacity of 10μL to 30μL.

5. The printhead comprising internal microchannels according to claim 1, characterized in that, The printing chip is rectangular in shape and includes a first surface and a second surface arranged opposite to each other. The first surface has a chip liquid inlet along its length, which is connected to the internal microchannel. The second surface has a plurality of nozzles, which are arranged in a row at equal intervals along its length and are all connected to the printing chip liquid inlet. The printing liquid in the internal microchannel enters the nozzles through the chip liquid inlet.

6. The printhead comprising internal microchannels according to claim 1, characterized in that, The printing chip is a thermal inkjet printing chip.

7. The printhead comprising internal microchannels according to any one of claims 1 to 6, characterized in that, The liquid inlet channel has a funnel-shaped liquid inlet that is cylindrical at the top and conical at the bottom.

8. The printhead comprising internal microchannels according to claim 7, characterized in that, The inlet channel is connected to a pipette for manual liquid addition.

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