LCD biological 3D printing device and printing method

Abstract

The application discloses an LCD biological 3D printing device and method, and belongs to the technical field of biological 3D printing. The LCD biological 3D printing device comprises a printing chamber and an electrical chamber. The bottom of the printing chamber is provided with a partition plate. The upper surface of the partition plate is provided with a liquid tank. The cabin body of the printing chamber is provided with a liquid adding structure for adding liquid into the liquid tank. The upper portion of the liquid tank is provided with a printing platform. The inside of the cabin body is provided with a lifting structure for driving the printing platform to lift. The inside of the cabin body is provided with a temperature controller. The electrical chamber is provided with arrayed solidification light sources. The solidification light sources are located directly below the liquid tank. The partition plate is provided with an LCD liquid crystal screen for allowing the light of the solidification light sources to penetrate. The liquid adding structure, the temperature controller, the lifting structure and the solidification light sources are electrically connected with a controller. The LCD biological 3D printing device and the printing method can solve the problems of poor biological cell activity and low precision of the existing 3D printing device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biological 3D printing, and particularly relates to an LCD biological 3D printing device and a printing method. BACKGROUND

[0002] At present, biological 3D printing technologies mainly include extrusion printing and DLP light curing printing, but they have some technical defects in practical application, mainly in terms of printing precision, speed, cost and cell activity maintenance.

[0003] Extrusion printing technology: due to the limitation of mechanical nozzle and pressure on the extrusion of cell suspension, the precision is low, and fine and complex biological structures cannot be printed. Extrusion printing usually needs a long time to build each layer, and the efficiency is low, which limits the possibility of large-scale printing.

[0004] DLP light curing printing technology: using expensive photosensitive resin and high-precision light projection system, the cost is high, and it is difficult to apply in large-scale biological 3D printing. In the traditional DLP printing process, ultraviolet light may cause damage to cells, reduce cell activity, and the control of environmental parameters such as temperature and humidity is not accurate, which affects cell growth.

[0005] The existing patent CN202010241015.2 discloses an LCD 3D printer and an LCD 3D printing system. The LCD 3D printer comprises a shell, a heat dissipation base, a heat-conducting light shield, a printing platform and a light source assembly. The heat dissipation base is fixedly installed in the shell, the heat-conducting light shield is fixedly installed on the heat dissipation base, the light source assembly is located in the heat-conducting light shield and is arranged on the heat dissipation base, and the printing platform is fixedly installed on the top of the heat-conducting light shield. There is an annular space between the heat-conducting light shield and the shell, a first air inlet and a first air outlet are formed in the shell and communicate with the annular space, and a suction member is arranged at the first air inlet. A second air inlet is formed in one side wall of the heat-conducting light shield, and a second air outlet is formed in the opposite side wall, and an exhaust member is arranged at the second air outlet. The LCD 3D printing system comprises the LCD 3D printer, and has the technical effect of improving the service life of the LCD screen. However, the above-mentioned patent cannot realize automatic liquid adding of the liquid, cannot control the parameters of the liquid, cannot guarantee the uniformity of the biological cell suspension, and cannot control the activity of the biological cells, which affects the activity of the biological cells, the printing precision and the printing speed. SUMMARY

[0006] The purpose of the present application is to provide an LCD biological 3D printing device and a printing method, which solves the problems of poor biological cell activity and low precision of the existing 3D printing device.

[0007] In order to achieve the above object, the present application provides a LCD biological 3D printing device, which comprises a printing chamber and an electrical chamber, the electrical chamber is located below the printing chamber, the bottom of the printing chamber is provided with a partition plate separating the printing chamber from the electrical chamber, the upper surface of the partition plate is provided with a liquid tank, the cabin of the printing chamber is provided with a liquid adding structure for adding liquid into the liquid tank, the upper portion of the liquid tank is provided with a printing platform, the inside of the cabin is provided with a lifting structure driving the printing platform to lift, and the inside of the cabin is provided with a temperature controller; the electrical chamber is provided with an array type curing light source, the curing light source is located directly below the liquid tank, the partition plate is provided with an LCD liquid crystal screen allowing the light of the curing light source to penetrate, and the liquid adding structure, the temperature controller, the lifting structure and the curing light source are electrically connected with a controller.

[0008] Preferably, the liquid tank comprises a liquid cavity, both ends of the liquid cavity are provided with mounting seats, the mounting seats are provided with mounting holes, locking bolts pass through the mounting holes to fix the liquid tank on the partition plate, and a release film is arranged between the bottom of the liquid cavity and the LCD liquid crystal screen.

[0009] Preferably, the liquid cavity is a stepped structure with a small opening size at the bottom and a large opening size at the top.

[0010] Preferably, an ultrasonic vibration plate is arranged on the outer wall of the liquid tank, the ultrasonic vibration plate is connected with an ultrasonic generator, the ultrasonic generator is connected with the controller, the ultrasonic vibration plate is used for ultrasonic mixing of liquid in the liquid tank, and the inside of the liquid tank is provided with a temperature sensor, a humidity sensor, an illumination intensity sensor and a cell concentration sensor which are electrically connected with the controller.

[0011] Preferably, the liquid adding structure comprises liquid storage pipes, the liquid storage pipes are fixedly arranged on the inner wall of the cabin, biological ink and cell buffer solution are respectively filled in the two liquid storage pipes, the liquid storage pipes are communicated with the liquid tank through conduits, and the biological ink and the cell buffer solution are respectively injected into the liquid tank through the conduits.

[0012] Preferably, the lifting structure comprises a stand column, the bottom end of the stand column is fixedly arranged on the partition plate, a lead screw is arranged on the stand column, both ends of the lead screw are rotationally connected with the stand column, a motor driving the lead screw to rotate is arranged in the electrical chamber, the motor is connected with the controller, the printing platform is arranged on a connecting seat, a nut matched with the lead screw is arranged on the connecting seat, and a guide rail guiding the sliding of the connecting seat is arranged on the stand column.

[0013] Preferably, a cabin door is hinged to the opening end of the cabin, an observation window is arranged on the cabin door, and an ultraviolet sterilization lamp and an illuminating lamp are arranged in the inside of the cabin.

[0014] Preferably, the curing light source comprises a fixing seat, the fixing seat is fixed in the electrical chamber, a parallel array of curing lamps is arranged in the inside of the fixing seat, and the curing lamps are electrically connected with the controller.

[0015] Preferably, the interior of the electrical chamber is provided with a total power supply and a temperature control power supply, the total power supply provides power output for the entire device, the temperature control power supply provides power output for the temperature controller, the total power supply and the temperature control power supply are connected with the controller, the interior of the electrical chamber is provided with a radiator, the shell of the electrical chamber is provided with a heat dissipation hole, the radiator is opposite to the heat dissipation hole, and the shell is provided with a control screen.

[0016] The printing method of the LCD biological 3D printing device has the steps of:

[0017] S1, turn on the ultraviolet sterilization lamp, sterilize the cabin body through the ultraviolet sterilization lamp, and turn off the ultraviolet sterilization lamp after sterilization is completed;

[0018] S2, select the printing mode through the control screen, and set the parameters of the printing mode;

[0019] S3, the liquid storage pipe adds a designed amount of biological ink and cell buffer to the liquid tank through the conduit, and the ultrasonic generator vibrates the liquid tank through the ultrasonic vibration plate to mix the biological ink and the cell buffer in the liquid tank;

[0020] S4, the motor drives the lead screw to rotate, the lead screw drives the printing platform to descend through the connecting seat, and the printing platform descends to the bottom of the liquid tank;

[0021] S5, turn on the curing light source, the controller controls the brightness of the pixel points on the LCD screen according to the setting of each layer of the printing structure, selects the light transmission part of the LCD screen, makes the photosensitive biological ink in the liquid tank solidify, and the motor drives the printing platform to gradually rise through the lead screw and the connecting seat, and the printing structure is formed by layer-by-layer stacking;

[0022] S6, the temperature sensor, the humidity sensor, the light sensor and the cell concentration sensor monitor the liquid in the liquid tank and send the parameters to the controller, the controller adjusts the temperature, the humidity, the light intensity and the cell concentration in the liquid tank in real time, and the temperature controller maintains the working temperature of the printing chamber at a constant temperature under the action of the controller.

[0023] Preferably, in S6, the real-time adjustment of the controller includes the following steps:

[0024] S61, obtain historical measurement data of the current printing layer; the historical measurement data includes the temperature, the humidity, the light intensity, the cell concentration and the suspension uniformity of the liquid tank, and the liquid amount, the ultrasonic vibration frequency and the motor displacement accuracy;

[0025] S62, pre-process and feature extraction are performed on the historical measurement data; the features include: temperature change rate of the liquid tank, correlation coefficient between liquid addition amount and cell concentration, influence index of ultrasonic vibration frequency on suspension uniformity, product of temperature and humidity, ratio of light intensity and light time, average light time and success rate change trend;

[0026] The pre-processing includes filtering, time alignment and normalization operation.

[0027] S63, the features with contribution greater than a first preset value are input into a target LCD biological 3D printing device prediction model through principal component analysis method, to obtain prediction data of the next printing layer; the target LCD biological 3D printing device prediction model is determined based on a multiple regression algorithm sub-model and a random forest algorithm sub-model;

[0028] S64, target loss function calculation is performed on the prediction data of the next printing layer and the actual data of the next printing layer, and parameters of the LCD biological 3D printing device are adjusted according to the target loss function, and the adjusted parameters are used for printing of the next printing layer.

[0029] Preferably, the real-time adjustment of the controller further includes:

[0030] Microscopic imaging of the current printing layer is obtained;

[0031] The reward function value corresponding to the microscopic imaging is determined according to the imaging quality index;

[0032] When the reward function value is greater than a third preset value, the parameters of the current printing layer are re-adjusted after all layers are printed; the re-adjustment is completed based on the reward function value corresponding to the microscopic imaging triggering the action instruction.

[0033] The LCD biological 3D printing device and the printing method have the following advantages and positive effects:

[0034] 1、The liquid adding structure is arranged in the cabin, and the liquid adding speed of the liquid adding structure is controlled under the action of the controller, and biological ink and cell buffer solution are added into the liquid tank in real time through the liquid adding structure, so that the preservation of the cell suspension liquid is facilitated, the influence of ultraviolet light on cell activity is reduced, and the cell activity and printing precision are improved.

[0035] 2、The ultrasonic vibration plate is arranged on the side wall of the liquid tank, and the biological ink and the cell buffer solution in the liquid tank are mixed online through the ultrasonic vibration plate, which is beneficial to improve the uniformity of the cell suspension liquid, improve the uniformity of the printing, and further improve the printing precision.

[0036] 3, the sensor is arranged in the liquid tank, detects the temperature, humidity, light intensity and other parameters of the cell suspension liquid in the liquid tank, a printing device prediction model is established, and the temperature, humidity, light intensity, cell concentration, liquid adding amount, ultrasonic vibration frequency and other parameters of the printing device are adjusted in real time through the controller, so that the printing environment is kept in a suitable cell survival environment, which is beneficial to improve the activity of the cells.

[0037] 4, the ultraviolet sterilization lamp is arranged in the cabin body, the sterile environment of printing is ensured, the safety and success rate of printing are improved, and the ultraviolet sterilization lamp is convenient to operate. The array type curing light source is beneficial to provide continuous, stable and uniform ultraviolet light, is convenient for curing of the photosensitive material, and is beneficial to improve the printing precision.

[0038] The technical scheme of the present application will be further described in detail below with reference to the drawings and embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 It is a structural schematic view of the embodiment of the present application.

[0040] Figure 2 It is a longitudinal sectional structure schematic view of the embodiment of the present application.

[0041] Figure 3 It is a three-dimensional structure schematic view of the inside of the printing chamber of the embodiment of the present application.

[0042] Figure 4 It is a front view structure schematic view of the inside of the printing chamber of the embodiment of the present application.

[0043] Figure 5 It is a schematic view of the internal structure of the embodiment of the present application.

[0044] Figure 6 It is a curing light source structure schematic view of the embodiment of the present application.

[0045] Figure 7 It is a three-dimensional structure schematic view of the liquid tank of the embodiment of the present application.

[0046] Figure 8 It is a sectional structure schematic view of the liquid tank of the embodiment of the present application.

[0047] Figure 9 It is a flowchart of the controller real-time adjustment of the LCD biological 3D printing device of the embodiment of the present application.

[0048] REFERENCE NUMERALS

[0049] 1. Printing chamber; 11. Chamber; 12. Door; 13. Observation window; 14. Partition; 15. Printing platform; 16. Temperature controller; 17. Liquid tank; 18. LCD screen; 19. Ultrasonic vibration plate; 110. Ultrasonic generator; 111. Liquid storage tube; 112. Guide tube; 113. Locking bolt; 114. Ultraviolet sterilization lamp; 115. Lighting lamp; 116. Column; 117. Lead screw; 118. Connecting seat; 119. Guide rail; 120. Mounting seat; 121. Mounting hole; 122. Liquid chamber; 123. Motor;

[0050] 2. Electrical compartment; 21. Housing; 22. Control panel; 23. Curing light source; 24. Main power supply; 25. Temperature control power supply; 26. Heat sink; 27. Mounting base; 28. Curing lamp; 29. ​​Heat dissipation holes. Detailed Implementation

[0051] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0052] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0053] like Figures 1-5 As shown, an LCD bio-3D printing device includes a printing chamber 1 and an electrical chamber 2. The electrical chamber 2 is located below the printing chamber 1. A partition 14 is provided at the bottom of the printing chamber 1 to separate the printing chamber 1 from the electrical chamber 2. The partition 14 can be configured as a heat-insulating partition 14 to reduce the impact of the electrical chamber 2 on the internal environment of the printing chamber 1, making it easier to maintain a constant printing environment in the printing chamber 1, which is beneficial to improving the printing activity of the bio-bearing process. When cleaning the liquid tank 17 inside the chamber 11, it can prevent the bio-ink from contaminating the electrical components inside the electrical chamber 2.

[0054] like Figure 7 , Figure 8The upper surface of the partition plate 14 is provided with a liquid tank 17 for filling biological ink and cell buffer for printing. The liquid tank 17 comprises a liquid cavity 122, and both ends of the liquid cavity 122 are fixedly provided with mounting seats 120, and the mounting seats 120 are provided with mounting holes 121, and the liquid tank 17 is fixed on the partition plate 14 through the mounting holes 121 by lock bolts 113.

[0055] The liquid cavity 122 has a stepped structure with a small bottom opening size and a large top opening size. On the one hand, the stepped structure facilitates the sinking of the printing platform 15 into the liquid tank 17, and on the other hand, it can accommodate more liquid to avoid pollution caused by liquid overflow.

[0056] The cabin body 11 of the printing chamber 1 is provided with a liquid adding structure for adding liquid into the liquid tank 17. The liquid adding structure comprises liquid storage pipes 111 fixedly arranged on the inner wall of the cabin body 11. The two liquid storage pipes 111 are respectively filled with biological ink and cell buffer, and the liquid storage pipes 111 are communicated with the liquid tank 17 through conduits 112, and the biological ink and the cell buffer are respectively injected into the liquid tank 17 through the conduits 112. The biological ink is a photosensitive material which undergoes photopolymerization under the action of ultraviolet light, thereby forming a 3D printed product with a fixed structure. The liquid storage pipes 111 are provided with electromagnetic flow valves, and the electromagnetic flow valves are connected with the controller. The mixing amount of the biological ink and the cell buffer is controlled by the controller, and the real-time addition of the biological ink and the cell buffer into the liquid tank 17 can be realized, which reduces the difficulty of preserving the cells after being filled into the biological ink, is conducive to maintaining the activity of the cells, and improves the flexibility of printing; and it also avoids filling too much biological ink and cell buffer into the liquid tank 17 at one time, which is not only conducive to reducing the influence of ultraviolet light on the activity of the cells, but also conducive to improving the printing efficiency.

[0057] An ultrasonic vibration plate 19 is fixedly arranged on the outer wall of the liquid tank 17, and the ultrasonic vibration plate 19 is connected with an ultrasonic generator 110, and the ultrasonic generator 110 is connected with the controller. The ultrasonic vibration plate 19 is fixed on the two side walls of the liquid tank 17, and the biological ink and the cell buffer in the liquid tank 17 are ultrasonically mixed. The biological ink and the cell buffer are ultrasonically mixed in real time by the ultrasonic vibration plate 19, which reduces the difficulty of preserving the mixed biological ink and cell buffer, provides the activity of the cells; and reduces the sedimentation of the cells, improves the uniformity of the cell suspension, and is conducive to improving the uniformity of the cell concentration in each layer of the printed structure and improving the cell printing quality.

[0058] The inside of the liquid tank 17 is provided with a temperature sensor, a humidity sensor, an illumination intensity sensor and a cell concentration sensor which are electrically connected with the controller, for real-time monitoring of the biological ink and the cell buffer in the liquid tank 17, so that the suspension is kept in an environment suitable for cell growth, which is conducive to improving the activity of the cells and the printing quality and improving the cell culture effect.

[0059] The curing light source 23 is arranged in an array in the electrical chamber 2 and is located directly below the liquid tank 17. The LCD display screen 18 is arranged on the partition plate 14 to allow the light of the curing light source 23 to pass through, and the liquid tank 17 is located directly above the LCD display screen. A release film is arranged between the bottom of the liquid cavity 122 and the LCD display screen 18 to facilitate separation of the printed and cured biological structure from the LCD display screen 18.

[0060] As shown in Figure 6 The curing light source 23 includes a fixing seat 27 fixed inside the electrical chamber 2. The fixing seat 27 is internally provided with a parallel array of curing lamps 28, which are electrically connected to the controller. The curing lamps 28 are UV lamps, and the arrayed curing lamps 28 are beneficial to provide continuous, stable, and uniformly distributed UV light for the printing process. The intensity of the UV light and the exposure time are controlled by the controller. Moreover, the parallel array of UV curing lamps 28 is more convenient for maintenance and repair.

[0061] The light-transmitting part on the LCD display screen 18 is determined by the brightness of the pixel points on the LCD display screen 18 controlled by the controller, thereby curing the specific shape in the liquid tank 17 to realize the printing of each layer of structure, and the biological 3D printed structure is formed after layer-by-layer stacking. The LCD display screen 18 significantly improves the printing accuracy and efficiency, reduces the influence of UV light on cell activity, and reduces the cost of the light-curing biological 3D printing device.

[0062] A printing platform 15 is arranged above the liquid tank 17, and a lifting structure for driving the printing platform 15 to ascend and descend is arranged inside the cabin body 11. The lifting structure includes a column 116 fixedly arranged at the bottom of the partition plate 14, a lead screw 117 arranged on the column 116, and both ends of the lead screw 117 rotatably connected to the column 116 through bearings. A motor 123 for driving the lead screw 117 to rotate is arranged in the electrical chamber 2, and the motor 123 is connected to the controller. The printing platform 15 is fixedly arranged on a connecting seat 118, and the connecting seat 118 is provided with a nut matched with the lead screw 117. The lead screw 117 drives the connecting seat 118 to move up and down through the nut, thereby gradually moving the printing platform 15 upwards, and the printing platform 15 gradually lifts the biological 3D printed product to realize layer-by-layer printing of the printed product. A guide rail 119 for guiding the sliding of the connecting seat 118 is fixedly arranged on the column 116, and the guide rail 119 is arranged on both sides of the lead screw 117 and parallel to the lead screw 117. The connecting seat 118 is provided with a guide groove matched with the guide rail 119, and the guide rail 119 is located in the guide groove and is in sliding connection with the guide groove.

[0063] The temperature controller 16, the liquid adding structure, the lifting structure, and the curing light source 23 in the cabin body 11 are electrically connected with the controller. The temperature controller 16 is manually set or controlled by the controller, so that the temperature in the printing chamber 1 is kept at a temperature suitable for cell survival, which is beneficial to improve the activity of cells. The temperature controller 16 is provided with an air outlet, through which the temperature in the printing chamber 1 can be adjusted while the humidity in the printing chamber 1 is adjusted, so that the environment in the printing chamber 1 is kept at the required temperature and humidity environment, which is beneficial to improve the activity of cells and improve the printing success rate.

[0064] The opening end of the cabin body 11 is hinged with a cabin door 12, through which the liquid tank 17 in the cabin body 11 is convenient to clean, and the daily maintenance and repair of the internal components are convenient. The cabin door 12 is provided with an observation window 13, and the transparent observation window 13 is convenient for the staff to observe the printing process in the printing chamber 1. The inside of the cabin body 11 is provided with an ultraviolet sterilization lamp 114 and an illuminating lamp 115. The ultraviolet sterilization lamp 114 is arranged at the top of the cabin body 11, and the inside of the cabin body 11 is sterilized before the biological ink is added and after the printing is completed, so that the cells are printed in a sterile environment, avoiding cross infection, which is beneficial to improve the activity of cells and also convenient for the sterilization treatment of the inside of the cabin body 11. The illuminating lamp 115 is a warm light tube, and the wavelength of the light will not affect the cells and photosensitive materials.

[0065] The inside of the electrical chamber 2 is provided with a total power supply 24 and a temperature control power supply 25, the total power supply 24 provides power output for the whole device, and the temperature control power supply 25 provides power output for the temperature controller 16. The total power supply 24 and the temperature control power supply 25 are connected with the controller. The inside of the electrical chamber 2 is provided with a radiator 26, the shell 21 of the electrical chamber 2 is provided with a heat dissipation hole 29, and the radiator 26 is opposite to the heat dissipation hole 29, which is used for heat dissipation of the electrical chamber 2. The shell 21 is provided with a touch control screen 22, through which the parameters and printing modes during printing can be selected, and the temperature, humidity, printing expected completion time and the like in the printing process can be displayed.

[0066] The controller is provided with an AI intelligent auxiliary system, which monitors and automatically adjusts the key parameters such as temperature, humidity, and light intensity in the printing process, and feeds back the adjustable light curing time, liquid adding speed, and ultrasonic vibration intensity, so as to ensure the printing quality and efficiency. The printing method of the above-mentioned LCD biological 3D printing device comprises the following steps:

[0067] S1, turn on the ultraviolet sterilization lamp 114, sterilize and disinfect the cabin body 11 through the ultraviolet sterilization lamp 114, and turn off the ultraviolet sterilization lamp 114 after sterilization is completed.

[0068] S2, select the printing mode through the control screen 22, and set the parameters of the printing mode.

[0069] S3. The storage tube 111 adds the designed amount of bio-ink and cell buffer to the liquid tank 17 through the conduit 112. The ultrasonic generator 110 vibrates the liquid tank 17 through the ultrasonic vibration plate 19 to mix the bio-ink and cell buffer in the liquid tank 17.

[0070] S4. Motor 123 drives lead screw 117 to rotate. Lead screw 117 drives printing platform 15 to descend through connecting seat 118. Printing platform 15 descends to the bottom of liquid tank 17.

[0071] S5. The curing light source 23 is turned on. The controller controls the brightness of the pixels on the LCD screen according to the settings of each printed layer, selecting the light-transmitting part of the LCD screen to cure the photosensitive bio-ink in the liquid tank 17. The motor 123 drives the printing platform 15 to rise gradually through the lead screw 117 and the connecting seat 118, stacking layers to form the printed structure. The controller controls the injection speed of bio-ink and cell buffer into the liquid tank 17, injecting bio-ink and cell buffer into the liquid tank 17 intermittently or in real time during printing.

[0072] S6, a temperature sensor, a humidity sensor, a light sensor, and a cell concentration sensor monitor the liquid in the liquid tank 17 and send the parameters to the controller. The controller adjusts the temperature, humidity, light intensity, and cell concentration in the liquid tank 17 in real time. Under the action of the controller, the temperature controller 16 maintains the operating temperature of the printing chamber 1 at a constant temperature.

[0073] After printing is complete, the printed bio-3D printed product is removed, the liquid tank 17 is cleaned, and the ultraviolet sterilization lamp 114 is turned on to sterilize the chamber 11.

[0074] like Figure 9 As shown, in S6, the real-time adjustment of the controller includes the following steps:

[0075] S61. Obtain historical measurement data of the current printing layer; historical measurement data includes: temperature, humidity, light intensity, cell concentration and suspension uniformity of the liquid bath, as well as liquid addition volume, ultrasonic vibration frequency and motor displacement accuracy;

[0076] It should be noted that 3D printing technology prints each layer based on printing parameters. The printing parameters for each printing layer can be the same or different. This embodiment of the invention uses the parameter adjustment of the current printing layer and the next printing layer as an example for illustration.

[0077] Specifically, the historical measurement data of the current printing layer includes multiple dimensions, including environmental parameters, device states, and biological indicators. The environmental parameters include the temperature, humidity, and light intensity of the liquid tank. The temperature of the liquid tank can be obtained by a temperature sensor, preferably a thermocouple sensor. The humidity of the liquid tank (i.e., the humidity of the cabin) can be obtained by a humidity sensor, preferably a capacitive humidity sensor. The light intensity of the liquid tank can be obtained by a light sensor, preferably a photosensitive sensor. The device states include motor displacement accuracy, liquid addition amount (liquid addition pump flow), and ultrasonic vibration frequency. The motor displacement accuracy can be obtained by the internal encoding unit of the controller. The liquid addition amount can be obtained by a component such as an electromagnetic flowmeter that can calculate liquid flow. The ultrasonic vibration frequency can be obtained by an ultrasonic generator, preferably an accelerometer. The biological indicators include cell concentration and suspension uniformity. The cell concentration can be obtained by a cell concentration sensor, preferably an optical density sensor. The suspension uniformity can be obtained by microscopic image analysis software.

[0078] S62, pre-process and feature extraction are performed on the historical measurement data. The features include the temperature variation rate of the liquid tank, the correlation coefficient of the liquid addition amount and the cell concentration, the influence index of the ultrasonic vibration frequency on the suspension uniformity, the product of the temperature and humidity, the ratio of the light intensity and light time, the average light time, and the success rate change trend.

[0079] The extracted features are key features and can be used as inputs for the target LCD biological 3D printing device prediction model.

[0080] Specifically, the features include multiple dimensions, including dynamic features, historical features, and interactive features. The dynamic features include the temperature variation rate of the liquid tank, the correlation coefficient (i.e., Pearson coefficient) of the liquid addition amount and the cell concentration, and the influence index of the ultrasonic vibration frequency on the suspension uniformity. The interactive features include the product of the temperature and humidity (synergistic effect) and the ratio of the light intensity and light time. The historical features include the average light time and the success rate change trend. The average light time is preferably the average light time of the past 5 printing layers, and the success rate change trend is preferably the success rate trend of the last 3 consecutive prints.

[0081] S63, features with a contribution degree greater than a first preset value are input into the target LCD biological 3D printing device prediction model through principal component analysis to obtain prediction data for the next printing layer. The target LCD biological 3D printing device prediction model is determined based on a multiple regression algorithm sub-model and a random forest algorithm sub-model.

[0082] Specifically, the principal component analysis method (PCA) is used to screen out core features with a contribution greater than a first preset value as input of the target LCD biological 3D printing device prediction model.

[0083] It should be noted that the first preset value can be set according to actual needs, and is not specifically limited here. Preferably, the first preset value is 85%, and the number of core features is preferably 15.

[0084] Among them, based on the supervised learning framework, the target LCD biological 3D printing device prediction model formed by the multiple regression algorithm sub-model and the random forest algorithm sub-model is used for prediction to obtain the prediction data of the next printing layer, such as the adjusted light time, the liquid addition rate, etc.

[0085] S64, the prediction data of the next printing layer and the actual data of the next printing layer are calculated by the target loss function, and the parameters of the LCD biological 3D printing device are adjusted according to the target loss function, and the adjusted parameters are used for printing the next printing layer.

[0086] Specifically, the training process of the target LCD biological 3D printing device prediction model uses gradient descent method to optimize the model weight, and minimizes the target loss function of the prediction data and the actual data of the next printing layer, wherein the actual data of the next printing layer can be the actual optimal parameter, which can be determined by manual annotation or experimental verification.

[0087] In an optional implementation, an incremental learning module can be provided in the system, and newly generated printing data (including successful and failed cases) is added to the training set periodically, and the model is retrained to adapt to dynamic factors such as equipment aging and material batch differences.

[0088] In some optional implementations, after the target LCD biological 3D printing device prediction model is trained, its accuracy can be evaluated by cross-validation to improve the generalization ability of the model.

[0089] Finally, the parameters of the LCD biological 3D printing device are adjusted according to the target loss function, and the adjusted parameters are used for printing the next printing layer. Among them, the adjusted parameters can be transmitted to the mechanical control structure of the printer to automatically perform light intensity adjustment, motor lifting speed adjustment, liquid addition amount adjustment, etc., to prepare for the printing of the next printing layer.

[0090] In some optional implementations, the preprocessing includes filtering, time alignment, and normalization operations.

[0091] The real-time adjustment of the controller also includes:

[0092] Obtaining a microscopic image of the current printing layer;

[0093] determine a reward function value corresponding to the microscopic imaging according to the imaging quality index;

[0094] When the reward function value is greater than a third preset value, the parameters of the current printing layer are re-adjusted after all layers are printed, and the re-adjustment is triggered by an action instruction based on the reward function value corresponding to the microscopic imaging.

[0095] Specifically, the filtering (noise reduction processing) includes Kalman filtering of the temperature signal and the ultrasonic vibration signal to eliminate mechanical interference in the device operation. The time alignment (time synchronization) includes aligning the data of different sampling frequencies through timestamps, such as aligning the sampling frequencies of 1Hz temperature data and 10Hz ultrasonic vibration data. The normalization includes scaling each parameter in the historical measurement data to the [0, 1] interval, such as linearly mapping the temperature according to 25℃-45℃ to avoid the influence of the dimension on the model training.

[0096] Secondly, a reward function of the imaging quality index is defined based on the reinforcement learning framework, wherein the imaging quality index includes cell survival rate, structure precision and energy consumption, and the reward function is specifically:

[0097] R = 0.7 x cell survival rate + 0.2 x structure precision - 0.1 x energy consumption.

[0098] When the reward function value is greater than a third preset value, the parameters of the current printing layer are re-adjusted after all layers are printed, and the re-adjustment is triggered by an action instruction based on the reward function value corresponding to the microscopic imaging. When the deviation exceeds the set threshold, the online fine tuning of the parameters is triggered, that is, the parameter space is explored through the Q-learning algorithm, the control strategy is gradually optimized, and the dependence on the historical measurement data is reduced.

[0099] The third preset value can be freely set according to actual needs, and is not specifically limited here.

[0100] The following is a comparison and verification between the real-time adjustment method of the controller of the application and the traditional printing method of fixed parameters, specifically including:

[0101] Control group: traditional printing method of fixed parameters.

[0102] Experimental group: AI-assisted dynamic adjustment method of the application.

[0103] Evaluation index: printing success rate, cell survival rate, and average time consumption.

[0104] 1. Model construction and training

[0105] Model architecture: hybrid model architecture combining supervised learning and reinforcement learning.

[0106] 1.1, Supervised learning module: Random Forest Regressor (100 decision trees), predict optimal exposure time, liquid loading rate for next layer.

[0107] Input: 15-dimensional feature vector selected.

[0108] Output: Adjusted parameters (UV intensity ±10%, liquid loading rate ±5 mL / min).

[0109] Loss function: Mean Squared Error (MSE) + print success rate penalty term.

[0110] Training parameter settings: Use Adam optimizer, learning rate 0.001, batch size 32, iterate 500 rounds.

[0111] 1.2, Reinforcement Learning Module:

[0112] State space: current environmental parameters, device status, printed layer number.

[0113] Action space: discrete action set (e.g. "increase exposure time by 5%" "reduce vibration frequency by 10Hz").

[0114] Reward function:

[0115] R = 0.7 × cell survival rate + 0.2 × structure accuracy - 0.1 × energy consumption.

[0116] Algorithm: Deep Q Network (DQN), experience replay buffer capacity 1000, ε-greedy policy, ε = 1.

[0117] 1.3, Training process:

[0118] Initial stage uses historical measurement data to pre-train supervised model;

[0119] During online printing, the reinforcement learning module explores the action space based on the prediction results of the supervised model.

[0120] Each time a complete printing is completed, update the DQN network weights, preferentially replay failed case data.

[0121] 2. Real-time control and dynamic optimization

[0122] During printing, the system performs closed-loop control:

[0123] 2.1, Before each layer printing:

[0124] Each sensor collects real-time data to generate a feature vector.

[0125] Supervised model outputs parameter adjustment suggestions (e.g. exposure time from 8s to 8.4s). Reinforcement learning module selects actions according to the current state (e.g. "slightly increase liquid loading").

[0126] 2.2, after printing each layer:

[0127] The optical microscopic imaging system detects the quality of the current layer (edge definition, cell distribution); if an abnormality (such as blurriness > 5%) is detected, the parameter backtracking is triggered;

[0128] - Compare the predicted parameters with the actual results, and correct the model bias;

[0129] - Enable the backup control strategy (such as fixed liquid addition rate mode).

[0130] Add the data of the current layer to the incremental learning queue for model fine-tuning.

[0131] 3, model iteration and verification

[0132] Incremental update: retrain the model after 50 cumulative printing tasks.

[0133] - Keep the core feature weights and only update the end decision layer parameters.

[0134] - Use the elastic weight consolidation (EWC) algorithm to prevent catastrophic forgetting.

[0135] - Verification experiment:

[0136] Control group: fixed parameters (exposure time 8s, liquid addition rate 10mL / min). Experimental group: AI dynamically adjusts the parameters.

[0137] The final experimental results are shown in Table 1:

[0138]

[0139]

[0140] The present application realizes the self-adaptive optimization of printing parameters through a data-driven deep learning framework. From multi-dimensional data acquisition to hybrid model training, to real-time closed-loop control, each step is customized for the special needs of biological printing (such as cell activity maintenance), and finally significantly surpasses traditional methods in efficiency, accuracy and reliability.

[0141] Therefore, the LCD biological 3D printing device and the printing method can solve the problems of poor biological cell activity and low precision of the existing 3D printing device.

[0142] It should be pointed out finally that the above examples are only used to illustrate the technical solutions of the present application but not to limit it, and although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can still be modified or replaced equivalently, and these modifications or equivalent replacements should not make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A printing method based on an LCD bio-3D printing device, characterized in that: The LCD bio-3D printing device includes a printing chamber and an electrical chamber. The electrical chamber is located below the printing chamber. A partition separates the printing chamber from the electrical chamber at the bottom of the printing chamber. A liquid tank is installed on the upper surface of the partition. A liquid filling structure is installed on the chamber of the printing chamber to add liquid to the liquid tank. A printing platform is installed above the liquid tank. A lifting structure is installed inside the chamber to raise and lower the printing platform. A temperature controller is installed inside the chamber. An array of curing light sources is installed in the electrical chamber. The curing light sources are located directly below the liquid tank. An LCD screen is installed on the partition to allow the light from the curing light sources to pass through. The liquid filling structure, temperature controller, lifting structure, and curing light sources are all electrically connected to the controller. The liquid addition structure includes two liquid storage tubes, each filled with bio-ink and cell buffer solution respectively. The liquid storage tubes are connected to the liquid tank through a conduit, and the bio-ink and cell buffer solution are injected into the liquid tank respectively through the conduit. An ultrasonic vibration plate is installed on the outer wall of the liquid tank. The ultrasonic vibration plate is connected to an ultrasonic generator, which is connected to a controller. The ultrasonic vibration plate performs ultrasonic mixing on the liquid in the liquid tank. A temperature sensor, a humidity sensor, a light intensity sensor, and a cell concentration sensor are installed inside the liquid tank and are electrically connected to the controller. The lifting structure includes a column, the bottom of which is fixedly mounted on a partition plate. A lead screw is mounted on the column, and both ends of the lead screw are rotatably connected to the column. A motor that drives the lead screw to rotate is installed in the electrical room. The motor is connected to a controller. The printing platform is mounted on a connecting seat, and a nut that matches the lead screw is installed on the connecting seat. The printing method based on an LCD bio-3D printing device includes the following steps: S1. Turn on the ultraviolet sterilization lamp inside the chamber to disinfect and sterilize the chamber. Turn off the ultraviolet sterilization lamp after sterilization is complete. S2. Select the printing mode and set the parameters of the printing mode through the control panel set on the casing of the electrical room; S3. The storage tube adds the designed amount of bio-ink and cell buffer to the liquid tank through the conduit. The ultrasonic generator vibrates the liquid tank through the ultrasonic vibration plate to mix the bio-ink and cell buffer in the liquid tank. S4. The motor drives the lead screw to rotate, and the lead screw drives the printing platform to descend through the connecting seat. The printing platform descends to the bottom of the liquid tank. S5. Turn on the curing light source. The controller controls the brightness of the pixels on the LCD screen according to the settings of each printed layer, selects the light-transmitting part of the LCD screen, and cures the photosensitive bio-ink in the liquid tank. The motor drives the printing platform to rise gradually through the lead screw and connecting seat, stacking layer by layer to form the printed structure. S6, temperature sensor, humidity sensor, light sensor and cell concentration sensor monitor the liquid in the liquid tank and send the parameters to the controller. The controller adjusts the temperature, humidity, light intensity and cell concentration in the liquid tank in real time. The temperature controller maintains the working temperature of the printing chamber at a constant temperature under the action of the controller. In step S6, the real-time adjustment of the controller includes the following steps: S61. Obtain historical measurement data of the current printing layer; the historical measurement data includes: temperature, humidity, light intensity, cell concentration and suspension uniformity of the liquid bath, as well as liquid addition volume, ultrasonic vibration frequency and motor displacement accuracy; S62. Preprocess and extract features from the historical measurement data; the features include: the temperature change rate of the liquid tank, the correlation coefficient between the liquid volume and the cell concentration, the influence index of the ultrasonic vibration frequency on the suspension uniformity, the product of temperature and humidity, the ratio of light intensity to light exposure time, and the trend of average light exposure time and success rate. Preprocessing includes: filtering, time alignment, and normalization. S63. Using principal component analysis, features with a contribution greater than a first preset value are input into the prediction model of the target LCD bio-3D printing device to obtain the prediction data for the next printing layer; the prediction model of the target LCD bio-3D printing device is determined based on a multivariate regression algorithm sub-model and a random forest algorithm sub-model. S64. Calculate the target loss function by combining the predicted data of the next printing layer with the actual data of the next printing layer, and adjust the parameters of the LCD bio-3D printing device according to the target loss function, and use the adjusted parameters for printing the next printing layer.

2. The printing method based on an LCD bio-3D printing device according to claim 1, characterized in that: The liquid tank includes a liquid cavity, and mounting seats are provided at both ends of the liquid cavity. The mounting seats are provided with mounting holes. Locking bolts are used to fix the liquid tank to the partition through the mounting holes. A release film is provided between the bottom of the liquid cavity and the LCD screen. The liquid cavity has a stepped structure with a small bottom opening and a large top opening.

3. The printing method based on an LCD bio-3D printing device according to claim 1, characterized in that: The liquid storage pipe is fixedly installed on the inner wall of the cabin.

4. The printing method based on an LCD bio-3D printing device according to claim 1, characterized in that: The column is equipped with a guide rail that guides the sliding of the connecting seat.

5. The printing method based on an LCD bio-3D printing device according to claim 1, characterized in that: The opening of the cabin is hinged to a door, which is equipped with an observation window. The interior of the cabin is equipped with ultraviolet sterilization lamps and lighting lamps. The curing light source includes a mounting base, which is fixed inside the electrical room. The mounting base contains a parallel array of curing lamps, which are electrically connected to the controller.

6. The printing method based on an LCD bio-3D printing device according to claim 1, characterized in that: The electrical compartment is equipped with a main power supply and a temperature control power supply. The main power supply provides power output to the entire device, and the temperature control power supply provides power output to the temperature controller. Both the main power supply and the temperature control power supply are connected to the controller. The electrical compartment is equipped with a radiator, and the casing of the electrical compartment has heat dissipation holes. The radiator faces the heat dissipation holes, and the casing is equipped with a control panel.

7. The printing method based on an LCD bio-3D printing device according to claim 1, characterized in that, Real-time adjustments to the controller also include: Obtain a microscopic image of the current printed layer; The reward function value corresponding to the microscopic imaging is determined based on the imaging quality index; When the reward function value is greater than the third preset value, the parameters of the current printed layer are readjusted after all layers have been printed; the readjustment is completed based on the action command triggered by the reward function value corresponding to the microscopic imaging.

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