Biological 3D printing nozzle

Abstract

The invention relates to a biological 3D printing nozzle. The biological 3D printing nozzle is arranged in the horizontal direction. The biological 3D printing nozzle comprises a second storage part, a first communication part and a second communication part. The second storage part is provided with a cavity which is used for temporarily storing ink and has an adjustable space size, and the upward lifting speed of the ink can be greater than or equal to the precipitation speed of solid particles in the ink in a manner of rotating along the axis during the storage period of the ink stored by the biological 3D printing nozzle, so that the pretreatment of the ink is executed; the first communication part is communicated with a first unit serving as a material storage mechanism and is provided with an acquisition unit for acquiring data information related to solid particles in ink; the second communication part is communicated with a third unit serving as a nozzle mechanism, and ink temporarily stored in the second storage part enters the nozzle through the second communication part. According to the biological 3D printing spray head, the total number of precipitated particles in the unit area of the bottom is reduced, and the function of preventing precipitation of low-viscosity ink mixed with solid particles is achieved.

Description

[0001] The original basis of this divisional application is a patent application with the application number 202310776252.2, the application date of June 28, 2023, and the invention title of "A Biological 3D Printing System and Method". It claims the priority of a patent application with the application number 202310464112.1, and the priority date is April 26, 2023. Technical Field

[0002] The present invention relates to the technical field of 3D printing, and particularly to a biological 3D printing nozzle. Background Art

[0003] Biological 3D printing refers to the process of printing biological materials (including natural biological materials, synthetic biological materials, or cell solutions) into a designed three-dimensional structure through the principles and methods of 3D printing. Different from ordinary 3D printing technology, the biological tissues or organs produced by biological 3D printing technology also have certain biological functions and need to provide conditions for the further growth of cells and tissues. Due to the above characteristics, biological 3D printing technology faces many specific technical problems in its development.

[0004] CN104552956A discloses a clean and easy-to-use biological material printing nozzle. The printing nozzle includes a nozzle housing, a biological material extrusion driving module, a contact temperature control module, and a biological material quick replacement module; the biological material extrusion driving module includes a high-precision servo electric cylinder, an electric cylinder push rod, an annular magnet limiter, and a syringe push rod head from top to bottom, and is coaxially arranged; the contact temperature control module includes a semiconductor refrigeration sheet, an external fluid cooling circulation system, and a fixed gland. The hot end face of the semiconductor refrigeration sheet is attached to the liquid cooling head, and the cold end face is attached to the inner wall of the fixed gland; the biological material replacement module includes a syringe, a cold guide sleeve, and a heat preservation sleeve; magnets with different polarities are arranged in the magnet mounting holes of the fixed gland and the cold guide sleeve.

[0005] CN105670918A discloses a biological printer nozzle assembly and a biological printer. Among them, the biological printer nozzle assembly includes a nozzle and an extension rod spaced apart from the nozzle and adjacent to the nozzle outlet. The extension rod is provided with a slender flow channel for enabling the fluid printing unit of the biological printing material to be directionally ejected through the flow channel. The biological printer nozzle assembly uses an extension rod with a slender flow channel adjacent to the nozzle outlet, and the fluid printing unit of the biological printing material is directionally ejected through the flow channel. The slender flow channel can perform directional sorting on the fluid printing unit and reduce the possibility of blockage.

[0006] However, the nozzle mechanisms of existing technologies are usually placed vertically, with a relatively long height direction, obvious particle precipitation phenomenon, and the structure printed first is the area with the most serious particle precipitation, resulting in an uneven phenomenon where the structure printed first has more particles and the structure printed later has fewer particles. Moreover, it is also easy to cause nozzle blockage. Especially when the ink selected is low-viscosity ink mixed with solid particles, the unevenness of the printed structure will be amplified, making it difficult to apply to the 3D printing process with high printing accuracy requirements.

[0007] In addition, on the one hand, there are differences in the understanding of those skilled in the art; on the other hand, when the applicant made this invention, a large number of documents and patents were studied, but due to space limitations, all details and contents were not listed in detail. However, this does not mean that this invention does not possess the features of these existing technologies. On the contrary, this invention already possesses all the features of the existing technologies, and the applicant reserves the right to add relevant existing technologies in the background art. Summary of the Invention

[0008] Aiming at the deficiencies of the existing technology, the present invention provides a biological 3D printing system and method to solve at least some of the above technical problems.

[0009] The present invention discloses a biological 3D printing system, which includes: a first unit for storing ink with solid particles; a third unit for ejecting the ink to print a 3D structure. Preferably, the first unit can generally serve as the material storage mechanism of the biological 3D printing system, the second unit can generally serve as the nozzle mechanism of the 3D printing system, and the third unit can generally serve as the nozzle mechanism of the biological 3D printing system.

[0010] Preferably, the biological 3D printing system is configured with a second unit arranged horizontally for preprocessing the ink. The second storage part of the second unit can receive the ink flowing out of the first unit and store the ink until it is output to the third unit when there is a printing requirement. Among them, the second storage part can at least make the upward lifting speed of the ink greater than or equal to the precipitation speed of at least some solid particles in the ink by rotating along the axis during the period when the ink is stored in the second unit, so as to perform preprocessing on the ink.

[0011] The nozzle mechanisms of conventional bio-3D printing systems (i.e., the second unit of the present invention) are all vertically placed, with a relatively long height direction. The phenomenon of particle sedimentation is obvious, and the structure printed first is the area with the most serious particle sedimentation, resulting in an uneven phenomenon where the structure printed first has more particles and the structure printed later has fewer particles. In contrast, the second unit of the present invention is horizontally placed, that is, the distance in the height direction is reduced, the total number of sedimented particles per unit area at the bottom is reduced, and the printed structure sequence is horizontally unfolded, that is, the ink near the opening side exits first, and the deposition direction is the height direction, and there will be no obvious difference in the total number of particles between the first printed structure and the last printed structure.

[0012] According to a preferred embodiment, the second storage part can rotate around the axis driven by the third motor, wherein the third motor is controlled by the control signal generated by the control unit to drive the second storage part to perform one-way continuous rotation or two-way swing rotation.

[0013] The present invention achieves the anti-sedimentation function of the low-viscosity ink mixed with solid particles by rotating the horizontally placed second storage part around the axis and driving the ink mixed with solid particles in the second storage part to rotate synchronously.

[0014] According to a preferred embodiment, an active part driven by the second motor to move along the axis of the second storage part is arranged in the second storage part. The active part can move in a direction away from the opening to introduce the ink into the second storage part with a tendency to increase the storage space, and the active part can move in a direction close to the opening to discharge the ink from the second storage part with a tendency to decrease the storage space.

[0015] The present invention adopts a stirring method without a stirring paddle, which can output the ink by means of a motor pushing the active part (such as a piston), rather than adopting a pneumatic injection method with a stirring paddle. This is because the pneumatic injection method is a constant-pressure injection, not a constant-flow injection. The injection flow rate is related to the gas pressure, the internal structure of the pipeline, and the ink viscosity. When printing materials with slightly changing viscosities during the printing process, it is easy to cause uneven flow rates and produce unqualified printed structures. At the same time, it is generally difficult to control the printing of low-viscosity materials by pneumatic printing. The cost of a pneumatic valve with a control accuracy of about 0.1 kPa is much higher than that of a motor structure with the same control accuracy. Therefore, the horizontally placed rotatable second storage part of the present invention can output the ink by means of a motor pushing the active part, obtaining better printing stability and control accuracy at low cost.

[0016] According to a preferred embodiment, the second unit is connected to the first unit and the third unit respectively through different connecting parts, wherein each connecting part is correspondingly provided with a switching part connected to the control unit by an independent signal, and all the switching parts responding to the control signal of the control unit can be arranged in a manner that they are not in a connected state at the same time.

[0017] Generally, the printing accuracy of outputting ink by means of a motor pushing a piston is negatively correlated with the diameter of the second storage unit. Therefore, in order to improve the printing accuracy, the diameter of the second storage unit should not be too large. However, a second storage unit with a small diameter will result in the need for frequent manual refilling during continuous production, which will affect the printing efficiency. The present invention automatically controls each on-off unit and each motor through a control unit, so that the second storage unit can automatically refill materials from the enclosed first storage unit with a relatively larger storage space as needed, thereby achieving efficient printing. And the feeding process, storage process and / or discharging process of the second unit can be adjusted by the control signal generated by the control unit, so that the biological 3D printing system of the present invention can further improve the printing accuracy and make the material distribution inside the printed structure more uniform.

[0018] According to a preferred embodiment, a collection unit for acquiring data information related to solid particles in the ink can be configured on the first connecting portion connected to the first unit and the second unit, wherein the data information related to the solid particles includes at least the number of particles and / or the particle size.

[0019] The collection unit of the present invention can use an optical particle counting method to obtain data information related to solid particles contained in the ink circulating in the first connecting part, wherein the data information related to the solid particles may at least include the number of particles and / or the size of the particles.

[0020] According to a preferred embodiment, the control unit is capable of adjusting the output power of the second motor at least based on the data information related to the solid particles acquired by the acquisition unit and / or the physicochemical characteristics of the ink.

[0021] The control unit of the present invention can determine the number and / or particle size of solid particles entering the second storage section in any time series based on the data information obtained by the acquisition unit, and can simulate the residence position of different solid particles in each time series batch after entering the cavity of the second storage section with the ink in combination with the physicochemical properties of the ink, thereby judging the real-time distribution state of the solid particles in the second storage section, and timely generating at least a control signal for regulating the operating state of the second unit to achieve a basically uniform distribution of solid particles in the second storage section based on the number and / or particle size factors.

[0022] According to a preferred embodiment, the first unit is configured with a first storage portion for containing ink, and a stirring blade driven by a first motor to rotate can be configured in the first storage portion.

[0023] Such an arrangement can enable the ink contained in the first storage portion to be in a stirred state of motion, so as to achieve the anti-settling function of the low-viscosity ink mixed with solid particles.

[0024] According to a preferred embodiment, the first storage portion is provided with a gas valve that is restricted to open unidirectionally, wherein the opening degree of the gas valve can be adjusted at least based on the change of the stirring mode of the stirring blade.

[0025] Since ink is generally a non-Newtonian compressible fluid, and the material pipe, material cylinder, etc. may have a certain pressure deformation, during the printing process, the ink accumulating a certain pressure will continue to eject outward through the nozzle to release the pressure after the printing stops. This phenomenon of the ink continuing to flow out is generally called the drooling phenomenon. To avoid the drooling phenomenon from affecting the surface quality of the printed structure, the biological 3D printing system of the present invention can use the first on-off portion to close and lock the pressure in the first storage portion, so as to greatly reduce the drooling phenomenon and improve the forming quality.

[0026] According to a preferred embodiment, the third unit is configured with a nozzle arranged in the vertical direction, and the temperature of the ink ejected from the nozzle onto the forming platform is adjusted at least by a temperature control component, wherein the moving component configured in the third unit can adjust the relative positional relationship between the nozzle and the forming platform.

[0027] Such an arrangement can heat up or cool down the ink to be ejected through the temperature control component according to the requirements of ink printing, so that the ink ejected onto the forming platform through the nozzle can meet the temperature required for the printed structure.

[0028] The present invention also discloses a biological 3D printing method, which includes the following steps:

[0029] During the feeding process of the second unit, the movable member moves in a direction away from the opening with a tendency to increase the storage space to introduce the ink into the second storage portion;

[0030] During the ink storage process of the second unit, the second storage portion rotates around the axis to drive the ink in the second storage portion to rotate, and the second storage portion can rotate in such a way that the upward lifting speed of the ink is greater than or equal to the precipitation speed of at least part of the solid particles in the ink;

[0031] During the discharging process of the second unit, the movable member moves in a direction close to the opening with a tendency to decrease the storage space to discharge the ink from the second storage portion.

[0032] Preferably, at least the feeding process, the material storage process, and / or the discharging process of the second unit can be adjusted by a control signal generated by the control unit. Brief Description of the Drawings

[0033] Figure 1 is a simplified overall structural schematic diagram of the biological 3D printing system of the present invention;

[0034] Figure 2 is a simplified schematic diagram of the module connection relationship of a preferred embodiment of the biological 3D printing system provided by the present invention.

[0035] List of Reference Numerals

[0036] 1: nozzle; 2: temperature control component; 3: second communication part; 4: second on-off part; 5: second storage part; 6: moving part; 7: second motor; 8: third motor; 9: transition part; 10: first storage part; 11: air valve; 12: stirring blade; 13: first motor; 14: first communication part; 15: first on-off part; 16: forming platform; 100: first unit; 200: second unit; 300: third unit; 400: control unit; 500: acquisition unit. Detailed Embodiments

[0037] The following is a detailed description with reference to the drawings.

[0038] Figure 1 is a simplified overall structural schematic diagram of the biological 3D printing system of the present invention; Figure 2 is a simplified schematic diagram of the module connection relationship of a preferred embodiment of the biological 3D printing system provided by the present invention.

[0039] Example 1

[0040] The present invention discloses a biological 3D printing system, in particular a 3D printing system suitable for inks with low viscosity and mixed with solid particles, which at least includes a first unit 100 for storing ink, a second unit 200 for preprocessing the ink, and a third unit 300 for inkjet printing. Among them, the second unit 200 for preprocessing the ink can at least play a partial anti-settling function. Preferably, the ink can be preferentially stored in the first unit 100. When a printing operation needs to be performed, the ink in the first unit 100 can be first introduced into the second unit 200. The ink temporarily stored in the second unit 200 can be introduced into the third unit 300 according to the actual printing requirements, and finally the ink is ejected through the third unit 300. Preferably, the biological 3D printing system may further include a control unit 400 communicatively connected to the first unit 100, the second unit 200, and / or the third unit 300. Among them, the control unit 400 can generate control signals for regulating the first unit 100, the second unit 200, and / or the third unit 300 based on one or more parameters obtained by the acquisition unit 500.

[0041] Preferably, the ink can be stored in the inner cavity of the first storage part 10 of the first unit 100, and a maximum liquid level line and a minimum liquid level line are provided in the inner cavity of the first storage part 10. Any storage state of the ink in the first storage part 10 should be maintained within the space defined by the maximum liquid level line and the minimum liquid level line. Among them, the ink in the first storage part 10 at least includes a static storage state and a dynamic storage state. Preferably, the ink can usually be stored in the first storage part 10 in a dynamic storage state to avoid the precipitation of solid particles in the ink. Among them, when the ink stored in the first storage part 10 is lower than the minimum liquid level line, new ink can be replenished into the first storage part 10 at least, and the ink in the first storage part 10 can be in a static storage state when replenishing the ink. Preferably, the volume of the first storage part 10 can be further preferably 500 ml - 5 L.

[0042] Preferably, the ink in the first storage part 10 can at least be switched to a dynamic storage state under the drive of the stirring blade 12. The stirring blade 12 can be at least submerged by the ink. Among them, the stirring blade 12 can be any shape that can play a stirring role, so that the stirring blade 12 rotates around the rotating shaft under the drive of the first motor 13, thereby realizing the anti-settling function of the first unit 100 for the ink with low viscosity and mixed with solid particles.

[0043] Preferably, the first storage unit 10 is provided with a gas valve 11 that allows one-way flow from the outside to the inside of the first storage unit 10, so that only gas is allowed to enter the inside from outside the first storage unit 10, and gas is not allowed to be discharged from the inside of the first storage unit 10. Such a setting can reduce or even avoid the volatilization of ink and play a role in replenishing the air pressure in the first storage unit 10 in a timely manner. Further, the gas valve 11 can be provided above the highest liquid level line of the ink in the first storage unit 10, and preferably, it is provided at the top of the first storage unit 10.

[0044] Preferably, due to the stirring effect of the stirring blade 12 and the pressure control effect of the gas valve 11, the volatilization phenomenon of the ink can be promoted or inhibited. The control unit 400 can at least adjust the operating parameters of the stirring blade 12 and / or the gas valve 11 based on parameters such as the current ink inventory, ink temperature, and top air pressure in the first storage unit 10. Among them, the adjustment of the stirring mode of the stirring blade 12 can at least include the stirring speed and / or the stirring direction, and the adjustment of the operating parameters of the gas valve 11 can at least include the opening timing of the gas valve 11 and / or the parameters of the air pump connected to the gas valve 11.

[0045] Preferably, the ink in the first storage unit 10 can enter the second storage unit 5 configured in the second unit 200 through the first communication part 14. Among them, the second storage unit 5 is configured with a cavity with an adjustable space size for temporarily storing ink, and the ink temporarily stored in the second storage unit 5 can enter the nozzle 1 configured in the third unit 300 through the second communication part 3.

[0046] Preferably, the first communication part 14 and the second communication part 3 can be configured as tubular structures, and the materials thereof can both be selected as materials that do not react with the ink. Further, a hard tube can be preferably used to reduce the pressure accumulation on the tube wall. Preferably, corresponding on-off parts can be configured on both the first communication part 14 and the second communication part 3. The on-off part can at least be used to adjust the opening degree of the tubular communication part to achieve the control of the ink flow rate. Among them, the on-off part can be one or a combination of two of an electromagnetic valve, a piezoelectric valve, and a motor valve. Further, a small-inner-diameter tube valve can be preferably used. Further, the first on-off part 15 configured on the first communication part 14 and the second on-off part 4 configured on the second communication part 3 can be respectively communicatively connected to the control unit 400 to receive the control signal for switching the on-off state sent by the control unit 400. Among them, the control unit 400 can at least not simultaneously send the control signal of "switching the connection state" for the first on-off part 15 and the second on-off part 4, that is, the first on-off part 15 and the second on-off part 4 are not simultaneously in the connected state, or at least one on-off part is in the blocked state.

[0047] Preferably, when starting up, the third motor 8 disposed in the horizontally placed second unit 200 can drive the transition part 9 to rotate. The transition part 9 is connected to one side end of the second storage part 5 through at least part of its structure to drive the second storage part 5 to rotate synchronously. Preferably, the rotation mode of the third motor 8 can be regulated by the control unit 400. For example, it can be a continuous single-direction rotation counterclockwise or clockwise, or a combined swinging rotation in a certain rotation angle in the clockwise and counterclockwise directions. More preferably, it is a swinging rotation with a single direction not exceeding 360 degrees. Among them, the rotation of the third motor 8 at least ensures that the upward lifting speed of the ink is greater than or equal to the precipitation speed of the particles in the ink.

[0048] Preferably, the ink can flow into and / or out of the second storage part 5 through the opening disposed at one side end of the second storage part 5 (in the horizontal direction). Preferably, the movable part 6 disposed in the second storage part 5 defines the storage space of the ink in the second storage part 5. The movable part 6 can be configured as a piston or a structure having the same shape as the piston to achieve a sealed partition with an adjustable space size. Among them, by adjusting the position of the movable part 6 in the second storage part 5 to adjust the size of the storage space, the movable part 6 moves away from the opening to increase the storage space, and the movable part 6 moves closer to the opening to decrease the storage space. Further, the movement of the movable part 6 in the inner cavity of the second storage part 5 can provide power for the inflow and / or outflow of the ink. Preferably, the volume of the second storage part 5 can be 0 - 50 ml, and more preferably 0 - 10 ml.

[0049] Preferably, the third unit 300 disposed in the vertical direction can at least include a printing nozzle 1 and a forming platform 16. Among them, the forming platform 16 disposed below the printing nozzle 1 in the vertical direction can receive the ink ejected from the printing nozzle 1. Preferably, the inner diameter of the printing nozzle 1 can be 0.01 - 3 mm, and more preferably 0.05 - 0.8 mm.

[0050] Preferably, the third unit 300 can be configured with a motion component for adjusting the three-dimensional spatial position relationship between the nozzle 1 and the forming platform 16 to realize the three-dimensional spatial movement of the nozzle 1 and / or the forming platform 16 through the motion component. Among them, the motion mode of the motion component can be regulated by the control unit 400 to achieve precise positioning of the ejected ink based on the relative movement between the nozzle 1 and the forming platform 16. Further, a temperature control component 2 can be configured in a partial area between the second on-off part 4 on the second communication part 3 and the nozzle 1 (especially close to the nozzle 1) to at least adjust the temperature of the ink entering the nozzle 1 according to the ink printing requirement. The adjustment method can include heating and / or refrigeration, and the controlled temperature is more preferably 0 - 70 °C.

[0051] According to a preferred embodiment, the present invention prevents solid particles in the ink from precipitating during the printing process by arranging stirring blades 12 driven by a first motor 13 in a first unit 100, and an active body driven by a second motor 7 and a second storage part 5 driven by a third motor 8 in a second unit 200 arranged in the horizontal direction. Furthermore, it avoids uneven distribution of the internal material of the printed structure and the situation where the nozzle 1 is easily blocked. Further, although the above configuration can prevent the precipitation of solid particles through various configuration methods, thereby achieving the effect of uniform distribution of the internal material of the printed structure, for a printing process with high printing precision, it is necessary to adjust the operating parameters of the second unit 200 through a control unit 400 to change the flow mode of the ink flowing into and / or out of the second storage part 5, and then improve the uniformity of the material distribution by enhancing the dispersion of solid particles during the printing process. Preferably, the dispersion refers to the degree of uniform distribution of the internal material of the printed structure, which can be characterized by the degree of dispersion of the number and / or particle size of solid particles ejected from the nozzle 1 with the ink in the time series.

[0052] This is because the second communication part 3 is preferably a thin tube with a hollow interior. The ink mixed with solid particles flowing through the second communication part 3 can generally only flow in sequence according to the sequence of entering the second communication part 3. It is difficult to adjust the distribution of solid particles in the second communication part 3 where disordered flow is not likely to occur. Therefore, it is only possible to optimize the distribution state of solid particles in the second storage part 5 to control the sequence of the ink mixed with solid particles entering the second communication part 3.

[0053] Preferably, optimizing the distribution state of solid particles in the second storage part 5 requires at least regulating the feeding process of the second unit 200. However, since ink usually needs to be stored away from light, it is difficult for the acquisition unit 500 to directly monitor the distribution state of solid particles in the second storage part 5 in real time. Therefore, the control unit 400 of the present application can simulate the distribution state of solid particles in the second storage part 5 based on the data information related to the solid particles mixed in the ink obtained by the acquisition unit 500 arranged on the first communication part 14, and adjust the distribution state of solid particles in the second storage part 5 by generating a control signal, so as to ensure a relatively uniform distribution of solid particles in the ink entering the second communication part 3 and the nozzle 1, and achieve uniform distribution of the internal material of the printed structure.

[0054] Preferably, the acquisition unit 500 disposed on the first communication part 14 can use the optical particle counting method to obtain data information related to solid particles mixed in the ink flowing through the first communication part 14. Among them, the data information related to solid particles can at least include the number of particles and / or the particle size. Further, the acquisition unit 500 using the optical particle counting method can be based on the physical techniques of extinction (LE) or light scattering (LS), or a combination of both physical techniques to obtain data information. Exemplarily, the acquisition unit 500 can select a sensor implementing single-particle optical sensing or an improved device for such a sensor, wherein the selected device is applicable to ink.

[0055] Preferably, based on the data information obtained by the acquisition unit 500, the control unit 400 can determine the number of solid particles and / or the particle size entering the second storage part 5 at any time series. In combination with the physical and chemical properties of the ink, it can simulate the residence positions of different solid particles in the cavities of the second storage part 5 after entering with the ink in each time series batch, so as to judge the real-time distribution state of the solid particles in the second storage part 5, and timely generate at least control signals for regulating the operating state of the second unit 200 to achieve a substantially uniform distribution of the solid particles in the second storage part 5 based on the consideration of the number and / or particle size factors.

[0056] Preferably, when the control unit 400 simulates the residence position of the solid particles after entering the cavity of the second storage part 5 with the ink, this residence position is the final position predicted by the control unit 400 for the solid particles in the stationary second storage part 5. It is not the landing position of the solid particles, but also takes into account the further displacement of the solid particles that have landed at the bottom of the second storage part 5 at the landing position due to the subsequent pulling process of the moving part 6. In this regard, the control unit 400 can calculate the corresponding compensation distance to calculate the final position in combination with the landing position. Preferably, the control unit 400 can at least predict the landing positions of the solid particles in each time series based on the particle size of the solid particles, the average pulling speed of the moving part 6, and the position of the opening on the second storage part 5, and at least calculate the compensation distance based on the particle size and the remaining pulling distance of the moving part 6. Among them, the degree of influence of solid particles with different particle sizes can obtain the influence coefficient through experiments, and this influence coefficient is used to calibrate the compensation distance.

[0057] Preferably, for the case where the particle sizes of the solid particles entering the second storage part 5 are relatively uniform, that is, when the particle sizes of the solid particles captured by the acquisition unit 500 in a plurality of initial consecutive time series are all or mostly within a preset particle size range, the control unit 400 can drive the second motor 7 to drive the movable part 6 to move away from the opening in the second storage part 5 at a substantially uniform pulling speed. Further, the control unit 400 can compare in real time the relationship between the number of solid particles within the same particle size range in any plurality of consecutive adjacent time series and a preset number threshold, so as to adjust the output power of the second motor 7 based on the comparison result in combination with the physical and chemical properties of the ink, and then speed up or slow down the pulling speed of the movable part 6. Among them, the number threshold can at least include a maximum number threshold and a minimum number threshold. The situation exceeding the maximum number threshold indicates that solid particles with substantially the same particle size will enter the second storage part 5 in a relatively aggregated manner, and the situation exceeding the minimum number threshold indicates that solid particles with substantially the same particle size will enter the second storage part 5 in a relatively loose manner. Both the relatively aggregated manner and the relatively loose manner will affect the uniform distribution state of the solid particles in the second storage part 5. Preferably, the control unit 400 can only compare the particle number with the preset number threshold for the solid particles whose particle sizes are within the preset particle size range to reduce the operation load. Among them, the preset particle size range is at least determined based on the properties of the (produced or purchased) ink, so as to cover relatively more solid particles by selecting a relatively moderate particle size value.

[0058] Preferably, for the case where the particle sizes of the solid particles entering the second storage part 5 are relatively non-uniform, that is, when the particle sizes of the solid particles captured by the acquisition unit 500 in a plurality of initial consecutive time series at least partially exceed the preset particle size range, the control unit 400 can drive the second motor 7 to drive the movable part 6 to move away from the opening in the second storage part 5 at a substantially non-uniform pulling speed. Further, the pulling speed of the movable part 6 can at least change in a trend of first decreasing, then increasing, and then decreasing substantially after the second motor 7 provides an initial acceleration. Among them, since the different particle sizes of the solid particles and the time series of their entry will affect their landing positions and final positions in the second storage part 5, by setting at least two speed turning points, the pulling process of the movable part 6 can be divided into at least three sub-processes with different speed change trends. With the physical block of the movable part 6, the aggregation of relatively small particle size solid particles at the end far from the opening can be restricted through decelerated motion, and the aggregation of relatively large particle size solid particles near the opening can be restricted through accelerated motion. Further, the change range of the pulling speed can also be finely adjusted based on the relationship between the number of solid particles in a certain particle size range and the preset number threshold, and the fine adjustment method can be the same as or similar to the above preferred embodiment.

[0059] Preferably, after the second unit 200 finishes the feeding process, it can switch to the material storage process. During the material storage process, the control unit 400 can drive the third motor 8 to drive the second storage part 5 to rotate around the axis with the transition part 9. Among them, the control unit 400 can determine the rotation mode of the third motor 8 based on the distribution state of the solid particles in the second storage part 5 obtained by simulation. The rotation mode can be, for example, a single-direction continuous rotation in the counterclockwise or clockwise direction, or a combined swing rotation in the clockwise and counterclockwise directions at a certain rotation angle. Further preferably, it is a swing rotation with a single direction not exceeding 360 degrees.

[0060] Preferably, the rotation of the third motor 8 driven by the control unit 400 can at least ensure that the upward lifting speed of the ink is greater than or equal to the precipitation speed of the particles in the ink. Among them, the control unit 400 can estimate the precipitation speed of the solid particles with the largest particle size in the ink based on the number and particle size of the solid particles entering the second storage part 5 obtained by the acquisition unit 500, so as to set the rotation mode of the third motor 8.

[0061] Preferably, the control unit 400 can adjust the pushing speed output by the second motor 7 to the moving part 6 based on the printing requirement and adjust the rotation speed of the third motor 8 driving the second storage part 5 to match the pushing speed of the moving part 6, so as to ensure that the upward lifting speed of the ink is greater than or equal to the precipitation speed of the particles in the ink during the discharging process of the second unit 200.

[0062] Furthermore, based on the regulation of the feeding process of the second unit 200 by the control unit 400, the distribution state of the solid particles in the second storage part 5 is optimized. The control unit 400 then effectively regulates the discharging process of the second unit 200 by changing the operation modes of the second motor 7 and / or the third motor 8, so as to control the sequence of the ink entering the second communication part 3.

[0063] Preferably, the control unit 400 can assign corresponding sequences to the ink mixed with solid particles that is about to enter the second communication part 3. Such sequences are usually assigned to a unit volume of ink, so that the storage space of the second storage part 5 can be occupied by several unit volumes of ink, or it can be said that the storage space of the second storage part 5 contains several ink sets. Moreover, the ink set closer to the opening can be assigned a more forward sequence. When the second motor 7 drives the movable part 6 to move towards the direction close to the opening, the ink set with a more forward sequence can enter the second communication part 3 relatively earlier and flow in an orderly manner. This orderly flow means that the ink sets can flow in the second communication part 3 roughly according to the assigned sequences, and it is difficult to have disordered flows such as overtaking, stagnation, and mixing. Preferably, for a unit volume of ink (or an ink set), the unit volume can be determined by the control unit 400 based at least on the physical and chemical properties of the ink and solid particles and the structural parameters of the second storage part 5. And at any determined unit volume, the control unit 400 can define the space occupied by the ink sets of each sequence, and its spatial structure can be the same or different. Among them, different spatial structures are usually specially set by the control unit 400 based on the structural parameters and fluid characteristics of the second storage part 5, especially for the area near the opening of the second storage part 5.

[0064] Furthermore, since the fluid has a completely different flow pattern at a narrow opening from that in an open cavity, the control unit 400 can preferably perform a spatial structure of the ink sets in the area near the opening of the second storage part 5 based on the flow pattern of the ink at the narrow opening. It can roughly make the multiple ink sets in the area near the opening of the second storage part 5 show an expanding coating form in sequence as the sequence increases. This expanding coating form can be shown that the space occupied by the ink set with a relatively later sequence in two adjacent ink sets of different sequences can roughly cover the space occupied by the ink set with a relatively earlier sequence, thus forming a coating form. In other words, make a cross-section orthogonal to the rotation axis in the area near the opening of the second storage part 5, and the slice of this cross-section passes through the spaces occupied by at least two ink sets of different sequences. Based on this, the control unit 400 can at least achieve the exchange of some solid particles between the two spaces occupied by the ink sets of adjacent sequences during the discharging process by adjusting the third motor 8. Among them, the adjustment of the third motor 8 by the control unit 400 is at least executed according to the plan determined after simulating the discharging process of the second unit 200 based on the predicted solid particle distribution state of the second storage part 5.

[0065] Preferably, through the precise regulation of the control unit 400, the solid particles can enter the nozzle 1 with the ink according to the given sequence in such a way that the number of particles and / or the particle size are distributed approximately uniformly in the ink sets of each sequence, and are ejected towards the forming platform 16. Under the coordinated drive of the moving components, a uniformly distributed internal material of the printed structure is achieved.

[0066] Embodiment 2

[0067] This embodiment is a further improvement of Embodiment 1, and the repeated content will not be elaborated.

[0068] The present invention also discloses a biological 3D printing method, which may include the following steps:

[0069] S1. Add the low-viscosity ink mixed with solid particles into the first storage part 10, and turn on the first motor 13 to drive the stirring blade 12 to stir the low-viscosity ink mixed with solid particles to prevent particle precipitation;

[0070] S2. During the feeding process of the second unit 200, turn on the first on-off part 15, turn off the second on-off part 4, and start the second motor 7 to pull the moving part 6 to move away from the opening (shown as moving leftward) in a trend of increasing the storage space. Based on the movement of the moving part 6, the low-viscosity ink mixed with solid particles can be sucked from the first storage part 10 through the second communication part 3 into the second storage part 5. When the feeding requirement is reached, turn off the first on-off part 15;

[0071] S3. During the storage process of the second unit 200, turn on the third motor 8, and drive the second storage part 5 to rotate around the axis through the transition part 9 to drive the low-viscosity ink mixed with solid particles in the second storage part 5 to rotate, playing a role in preventing precipitation of the low-viscosity ink mixed with solid particles;

[0072] S4. During the discharging process of the second unit 200, turn on the second on-off part 4, and make the second motor 7 push the moving part 6 to move towards the opening (shown as moving rightward) in a trend of reducing the storage space, so that the ink reaches the nozzle 1 through the first communication part 14, and is ejected to the designated position on the forming platform 16 through the nozzle 1. After the current round of printing work is completed, turn off the second motor 7 and the second on-off part 4, where the completion of the current round of printing work can be that the ink in the second storage part 5 is used up for printing or the printing task ends;

[0073] S5. If the ink in the second storage part 5 is used up for printing, return to the above step S2. After replenishing the ink in the second storage part 55, repeat the above steps S3 and S4 until the printing task ends.

[0074] Preferably, the control unit 400 is at least capable of generating corresponding control signals during the feeding process, storage process, and / or discharging process of the second unit 200 to achieve uniform distribution of solid particles.

[0075] Exemplarily, the biological 3D printing method of the present invention can complete the following steps:

[0076] S1. Add 500 ml of 10% PLGA ink with low viscosity mixed with magnesium powder particles (diameter 30 microns) to the first storage part 10 with a volume of 500 ml. Turn on the first motor 13 to drive the stirring blade 12 to stir the ink with low viscosity mixed with solid particles at a speed of 30 revolutions per minute to prevent particle precipitation.

[0077] S2. During the feeding process of the second unit 200, turn on the first on-off part 15, turn off the second on-off part 4, and start the second motor 7 to drive the movable part 6 to move away from the opening in a direction to increase the storage space of 10 ml (shown as moving to the left in the figure) at the speed indicated by the control unit 400 (for example, 10 mm / s). Based on the movement of the movable part 6, the ink with low viscosity mixed with solid particles can be sucked from the first storage part 10 through the second communication part 3 into the second storage part 5. When the feeding requirement is reached, turn off the first on-off part 15.

[0078] S3. During the storage process of the second unit 200, turn on the third motor 8, and drive the second storage part 5 to rotate around the axis in the rotation mode indicated by the control unit 400 (reciprocating swing rotation with ±180° and a swing speed of 30° / s) through the transition part 9 to drive the ink with low viscosity mixed with solid particles in the second storage part 5 to rotate, playing a role in preventing precipitation of the ink with low viscosity mixed with solid particles.

[0079] S4. During the discharging process of the second unit 200, turn on the second on-off part 4, and make the second motor 7 drive the movable part 6 to move towards the opening in a direction to reduce the storage space (shown as moving to the right in the figure) at the speed indicated by the control unit 400 (for example, 6 μm / s), so that the ink reaches the nozzle 1 through the first communication part 14 (inner diameter 3 mm). The temperature control component 2 can be used to keep the ink temperature at 25°C. The ink can be ejected from the nozzle 1 outlet (inner diameter 0.5 mm) onto the forming platform 16 placed in the -30°C forming space. The movement speed of the movement component is 20 mm / s. After the current round of printing work is completed, turn off the second motor 7 and the second on-off part 4.

[0080] S5. If the ink in the second storage part 5 is used up during printing, return to step S2 above. After replenishing the ink in the second storage part 55, repeat steps S3 and S4 above until the printing task ends.

[0081] It should be noted that the above specific embodiments are exemplary. Those skilled in the art can come up with various solutions inspired by the disclosure of the present invention, and these solutions also fall within the scope of the disclosure of the present invention and within the protection scope of the present invention. Those skilled in the art should understand that the description and drawings of the present invention are illustrative and do not constitute a limitation on the claims. The protection scope of the present invention is defined by the claims and their equivalents. The description of the present invention contains multiple inventive concepts. Phrases such as "preferably", "according to a preferred embodiment", or "optionally" indicate that the corresponding paragraphs disclose an independent concept. The applicant reserves the right to file divisional applications based on each inventive concept. Throughout the text, the features guided by "preferably" are only optional ways and should not be understood as being necessarily provided. Therefore, the applicant reserves the right to waive or delete the relevant preferred features at any time.

Claims

1. A biological 3D printing nozzle, characterized in that The biological 3D printing nozzle is arranged horizontally; and The biological 3D printing nozzle includes: A second storage part (5), configured with a cavity whose space size can be adjusted for temporarily storing ink, and capable of making the upward lifting speed of the ink greater than or equal to the precipitation speed of solid particles in the ink during the period of storing ink in the biological 3D printing nozzle by rotating along the axis, so as to perform pretreatment on the ink; A first communication part (14), communicating with a first unit (100) serving as a storage mechanism, and configured with a collection unit (500) for acquiring data information related to solid particles in the ink; A second communication part (3), communicating with a third unit (300) serving as a nozzle mechanism, and the ink temporarily stored in the second storage part (5) enters the nozzle (1) through the second communication part (3).

2. The bio-3D printing nozzle according to claim 1, wherein, The collection unit (500) is connected to a control unit (400), The control unit (400) determines the number and / or particle size of solid particles entering the second storage part (5) at any time series based on the data information acquired by the collection unit (500). In combination with the physical and chemical properties of the ink, it can simulate the residence positions of different solid particles in the cavity of the second storage part (5) after entering with the ink in each time series batch, so as to judge the real-time distribution state of solid particles in the second storage part (5), and timely generate a control signal for regulating the operating state of the biological 3D printing nozzle to achieve a substantially uniform distribution of solid particles in the second storage part (5) considering factors such as quantity and / or particle size.

3. The bio-3D printing nozzle according to claim 1 or 2, characterized in that, It further includes a third motor (8) and a transition part (9), The rotation mode of the third motor (8) is regulated by the control unit (400), When starting, the third motor (8) drives the transition part (9) to rotate; The transition part (9) is connected to one end of the second storage part (5) through at least part of its structure to drive the second storage part (5) to rotate synchronously.

4. The bio-3D printing nozzle according to any one of claims 1 to 3, characterized in that, The rotation of the third motor (8) configured in the biological 3D printing nozzle ensures that the upward lifting speed of the ink is greater than or equal to the precipitation speed of particles in the ink.

5. The bio-3D printing nozzle according to any one of claims 1 to 4, characterized in that, An active part (6) is arranged in the second storage part (5); The active part (6) is used to define the storage space of the ink in the second storage part (5), and provide power for the inflow and / or outflow of the ink; Wherein, by adjusting the position of the active part (6) in the second storage part (5) to adjust the size of the storage space, the active part (6) moves in a direction away from the opening of the second storage part (5) in the horizontal direction to increase the storage space, and the active part (6) moves in a direction close to the opening to decrease the storage space.

6. The bio-3D printing nozzle according to any one of claims 1 to 5, characterized in that The active part (6) arranged in the second storage part (5) is driven to displace by a second motor (7), When the particle sizes of the solid particles captured by the collection unit (500) in multiple initial consecutive adjacent time series are all or mostly within a preset particle size range, the control unit (400) drives the second motor (7) to drive the active part (6) to move in the second storage part (5) in a direction away from the opening at a substantially uniform pulling speed; The control unit (400) divides the pulling process of the movable member (6) into at least three sub-processes with different speed change trends by setting at least two speed turning points. The pulling speed of the movable member (6) can at least change in a trend of first decreasing, then increasing, and then decreasing again after the second motor (7) provides an initial acceleration. Among them, the accumulation of solid particles with relatively small particle sizes away from the opening end is restricted by decelerating motion, and the accumulation of solid particles with relatively large particle sizes near the opening end is restricted by accelerating motion.

7. The bio-3D printing nozzle according to any one of claims 1 to 6, characterized in that When simulating the staying positions of solid particles after entering the cavity of the second storage part (5) along with the ink, the control unit (400) predicts the landing positions of the solid particles at each time series based on the particle size of the solid particles, the average pulling speed of the movable member (6) arranged in the second storage part (5), and the position of the opening on the second storage part (5), and calculates a compensation distance based on the particle size and the remaining pulling distance of the movable member (6). The control unit (400) predicts the final position of the solid particle in the stationary second storage part (5) by combining the landing position of the solid particle and the compensation distance.

8. The biological 3D printing nozzle according to any one of claims 1 to 7, characterized in that The first on-off part (15) arranged on the first communication part (14) and the second on-off part (4) arranged on the second communication part (3) are respectively in communication connection with the control unit (400) to receive the control signal for switching the on-off state sent by the control unit (400). Among them, the first on-off part (15) and the second on-off part (4) are not in the connected state at the same time.

9. The bio-3D printing nozzle according to any one of claims 1 to 8, characterized in that, The data information related to the solid particles includes the number of particles and / or the particle size.

10. The bio-3D printing nozzle according to any one of claims 1 to 9, characterized in that, The movable member (6) arranged in the second storage part (5) is a piston or a structure having the same shape as the piston to achieve a sealed partition with adjustable space size.

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