LCD biological 3D printing device and printing method

Abstract

The invention 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 room, a partition plate is arranged at the bottom of the printing chamber, a liquid groove is formed in the upper surface of the partition plate, a liquid adding structure for adding liquid into the liquid groove is arranged on a cabin body of the printing chamber, and a printing platform is arranged above the liquid groove; a lifting structure for driving the printing platform to lift is arranged in the cabin body, and a temperature controller is arranged in the cabin body; array type curing light sources are arranged in the electrical chamber, the curing light sources are located under the liquid tank, and the partition plate is provided with a liquid crystal display (LCD) through which light rays of the curing light sources penetrate; the liquid adding structure, the temperature controller, the lifting structure and the curing light source are all electrically connected with the controller. By the adoption of the LCD biological 3D printing device and method, the problems that biological cells printed by an existing 3D printing device are poor in activity and low in precision can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of biological 3D printing, and in particular to an LCD biological 3D printing device and a printing method. Background Art

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

[0003] Extrusion printing technology: Because the extrusion of cell suspensions is limited by mechanical nozzles and pressure, precision is low and intricate biological structures cannot be printed. Extrusion printing typically requires a long time to build each layer, resulting in low efficiency and limiting the possibility of large-scale printing.

[0004] DLP (Dry Lithium-ion Photopolymerization) printing technology uses expensive photosensitive resins and high-precision light projection systems, making it costly and difficult to apply in large-scale bio-3D printing. In traditional DLP printing, UV light can damage cells and reduce their activity, and imprecise control of environmental parameters such as temperature and humidity can affect cell growth.

[0005] Existing patent CN202010241015.2 discloses an LCD 3D printer and LCD 3D printing system. The LCD 3D printer includes a housing, a heat sink base, a thermal hood, a printing platform, and a light source assembly. The heat sink base is fixedly mounted within the housing, the thermal hood is fixedly mounted on the heat sink base, the light source assembly is located within the thermal hood and is disposed on the heat sink base, and the printing platform is fixedly mounted on the top of the thermal hood. An annular space exists between the thermal hood and the housing, and the housing is provided with a first air inlet and a first air outlet connected to the annular space, with an air suction member provided at the first air inlet. A second air inlet is provided on one side wall of the thermal hood, and a second air outlet is provided on the opposite side wall, with an air exhaust member provided at the second air outlet. The LCD 3D printing system includes an LCD 3D printer, achieving the technical effect of increasing the service life of the LCD screen. However, the above patent cannot realize automatic liquid addition, cannot control the parameters of the liquid, cannot guarantee the uniformity of the biological cell suspension, and is difficult to control the activity of the biological cells, which affects the activity of the organisms, printing accuracy and speed. Summary of the Invention

[0006] The purpose of the present invention is to provide an LCD biological 3D printing device and printing method to solve the problems of poor activity and low precision of biological cells printed by existing 3D printing devices.

[0007] To achieve the above objectives, the present invention provides an LCD biological 3D printing device, comprising a printing chamber and an electrical chamber, the electrical chamber being located below the printing chamber, a partition being provided at the bottom of the printing chamber to separate the printing chamber from the electrical chamber, a liquid tank being provided on the upper surface of the partition, a liquid adding structure being provided on the cabin body of the printing chamber to add liquid into the liquid tank, a printing platform being provided above the liquid tank, a lifting structure being provided inside the cabin body to drive the printing platform to rise and fall, and a temperature controller being provided inside the cabin body; an array-type curing light source being provided in the electrical chamber, the curing light source being located directly below the liquid tank, and an LCD screen being provided on the partition body to allow light from the curing light source to pass through; the liquid adding structure, temperature controller, lifting structure, and curing light source are all electrically connected to a controller.

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

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

[0010] Preferably, an ultrasonic vibration plate is provided on the outer wall of the liquid tank, the ultrasonic vibration plate is connected to the ultrasonic generator, the ultrasonic generator is connected to the controller, and the ultrasonic vibration plate ultrasonically mixes the liquid in the liquid tank; a temperature sensor, a humidity sensor, a light intensity sensor and a cell concentration sensor electrically connected to the controller are provided inside the liquid tank.

[0011] Preferably, the liquid adding structure includes a liquid storage tube, which is fixedly arranged on the inner wall of the cabin. The two liquid storage tubes are filled with biological ink and cell buffer respectively. The liquid storage tubes are connected to the liquid tank through a catheter, and the biological ink and cell buffer are respectively injected into the liquid tank through the catheter.

[0012] Preferably, the lifting structure includes a column, the bottom end of the column is fixedly set on the partition, a screw is provided on the column, both ends of the screw are rotatably connected to the column, a motor for driving the screw to rotate is provided in the electrical room, the motor is connected to the controller, the printing platform is provided on the connecting seat, a nut adapted to the screw is provided on the connecting seat, and a guide rail for guiding the sliding of the connecting seat is provided on the column.

[0013] Preferably, a door is hinged at one open end of the cabin, an observation window is provided on the door, and an ultraviolet sterilization lamp and an illumination lamp are provided inside the cabin.

[0014] Preferably, the curing light source includes a fixing base, which is fixed inside the electrical chamber. A parallel array of curing lamps is arranged inside the fixing base, and the curing lamps are electrically connected to the controller.

[0015] Preferably, a main power supply and a temperature-controlled power supply are provided inside the electrical room. The main power supply provides power output for the entire device, and the temperature-controlled power supply provides power output for the thermostat. Both the main power supply and the temperature-controlled power supply are connected to the controller. A radiator is provided inside the electrical room. Heat dissipation holes are provided on the shell of the electrical room. The radiator is opposite to the heat dissipation holes, and a control screen is provided on the shell.

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

[0017] S1. Turn on the UV sterilization lamp to disinfect and sterilize the cabin. Turn off the UV 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 tube adds a designed amount of bio-ink and cell buffer into the liquid tank through the catheter. The ultrasonic generator vibrates the liquid tank through the ultrasonic vibration plate to mix the bio-ink and cell buffer in the liquid tank;

[0020] S4. The motor drives the screw to rotate, and the 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 pixels on the LCD screen according to the settings of each layer of the printed structure. The light-transmitting portion of the LCD screen is selected to solidify the photosensitive bio-ink in the liquid tank. The motor drives the printing platform to gradually rise through the screw and the connecting seat, and the printed structure is stacked layer by layer.

[0022] S6, the temperature sensor, humidity sensor, light sensor and cell concentration sensor monitor the liquid in the tank and send the parameters to the controller, which adjusts the temperature, humidity, light intensity and cell concentration in the tank in real time; the thermostat 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, obtaining 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 tank, as well as liquid addition amount, ultrasonic vibration frequency, and motor displacement accuracy;

[0025] S62. Preprocessing and feature extraction are performed on the historical measurement data; the features include: the temperature change rate of the liquid tank, the correlation coefficient between the amount of liquid added 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 time, and the average light time and success rate change trend;

[0026] Preprocessing includes: filtering, time alignment, and normalization operations;

[0027] S63. Inputting features with contribution greater than a first preset value into a target LCD 3D bio-printing device prediction model using a principal component analysis method to obtain prediction data for the next printing layer; the target LCD 3D bio-printing device prediction model is determined based on a multivariate regression algorithm sub-model and a random forest algorithm sub-model;

[0028] S64, performing target loss function calculation on the predicted data of the next printing layer and the actual data of the next printing layer, adjusting parameters of the LCD biological 3D printing device according to the target loss function, and using the adjusted parameters for printing the next printing layer.

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

[0030] Obtain microscopic imaging of the current printing layer;

[0031] Determining a reward function value corresponding to the microscopic imaging according to an imaging quality index;

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

[0033] The advantages and positive effects of the LCD biological 3D printing device and printing method of the present invention are:

[0034] 1. The present invention is provided with a liquid adding structure in the cabin. The liquid adding speed of the liquid adding structure is controlled by the controller, and the bio-ink and cell buffer are added to the liquid tank in real time through the liquid adding structure, which facilitates the preservation of the cell suspension and reduces the effect of ultraviolet light on cell activity, which is beneficial to improving cell activity and printing accuracy.

[0035] 2. An ultrasonic vibration plate is provided on the side wall of the liquid tank, which is used to mix the bio-ink and cell buffer in the liquid tank online, which is beneficial to improve the uniformity of the cell suspension, improve the uniformity of printing, and thus improve the printing accuracy.

[0036] 3. A sensor is installed in the liquid tank to detect parameters such as the temperature, humidity, and light intensity of the cell suspension in the liquid tank, and a prediction model for the printing device is established. The controller is used to adjust the temperature, humidity, light intensity, cell concentration, liquid addition volume, ultrasonic vibration frequency and other parameters of the printing device in real time to keep the printing environment suitable for cell survival, which is beneficial to improving cell activity.

[0037] 4. A UV sterilization lamp is installed inside the chamber to ensure a sterile printing environment, which helps improve printing safety and success rate; the UV sterilization lamp is also easy to operate. The array-type curing light source helps provide continuous, stable and uniform UV light, facilitating the curing of photosensitive materials and improving printing accuracy.

[0038] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of the structure of an embodiment of the present invention;

[0040] Figure 2 A schematic diagram of the longitudinal cross-section structure of an embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of the internal three-dimensional structure of a printing chamber according to an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of the interior structure of a printing chamber according to an embodiment of the present invention;

[0043] Figure 5 Schematic diagram of the internal structure of an embodiment of the present invention;

[0044] Figure 6 This is a schematic diagram of the curing light source structure according to an embodiment of the present invention;

[0045] Figure 7 Schematic diagram of the three-dimensional structure of the liquid tank according to an embodiment of the present invention;

[0046] Figure 8 A schematic diagram of a cross-sectional structure of a liquid tank according to an embodiment of the present invention;

[0047] Figure 9 Schematic diagram of the process of real-time adjustment of the controller of the LCD 3D biological printing device according to an embodiment of the present invention.

[0048] Reference numerals

[0049] 1. Print chamber; 11. Cabin; 12. Cabin door; 13. Observation window; 14. Partition; 15. Print platform; 16. Thermostat; 17. Liquid tank; 18. LCD screen; 19. Ultrasonic vibration plate; 110. Ultrasonic generator; 111. Liquid storage tube; 112. Conduit; 113. Locking bolt; 114. UV sterilizer; 115. Illuminator; 116. Column; 117. Screw; 118. Connector; 119. Guide rail; 120. Mounting base; 121. Mounting hole; 122. Liquid chamber; 123. Motor

[0050] 2. Electrical room; 21. Housing; 22. Control panel; 23. Curing light source; 24. Main power supply; 25. Temperature control power supply; 26. Radiator; 27. Fixing seat; 28. Curing lamp; 29. ​​Heat dissipation holes. DETAILED DESCRIPTION

[0051] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the inventive product is usually placed when in use. These are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. In the description of the present invention, it should also be noted that, unless otherwise expressly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a communication between the internal parts of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

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

[0053] like Figure 1-Figure 5 As shown. An LCD biological 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 thermal insulation partition 14 as needed to reduce the impact of the electrical chamber 2 on the internal environment of the printing chamber 1, facilitate maintaining a constant printing environment in the printing chamber 1, and promote enhanced biological printing activity. When cleaning the liquid tank 17 in the chamber 11, biological ink can be prevented from contaminating the electrical equipment in the electrical chamber 2.

[0054] like Figure 7 、 Figure 8As shown. A liquid tank 17 is provided on the upper surface of the partition 14. This tank is used to hold the bio-ink and cell buffer used for printing. The tank 17 includes a liquid chamber 122, with mounting seats 120 fixedly disposed at both ends of the chamber. Mounting holes 121 are provided on the mounting seats 120, through which locking bolts 113 pass to secure the tank 17 to the partition 14.

[0055] The liquid chamber 122 is a stepped structure with a small bottom opening and a large top opening. The stepped structure facilitates the printing platform 15 to sink into the liquid tank 17 on the one hand, and can accommodate more liquid on the other hand to avoid contamination caused by liquid overflow.

[0056] The chamber 1's housing 11 is equipped with a liquid-feeding mechanism for adding liquid to a liquid tank 17. This mechanism includes liquid reservoirs 111, fixed to the inner wall of the chamber 11. Two liquid reservoirs 111 are filled with bio-ink and cell buffer, respectively. These reservoirs 111 are connected to the liquid tank 17 via conduits 112, which inject the bio-ink and cell buffer into the tank 17. Bio-ink is a photosensitive material that undergoes photopolymerization under ultraviolet light, forming a fixed-structure 3D printed product. An electromagnetic flow valve is provided on the liquid storage tube 111, which is connected to the controller. The mixing amount of the biological ink and the cell buffer is controlled by the controller, and the biological ink and the cell buffer can be added to the liquid tank 17 in real time, reducing the difficulty of preserving the cells after being filled with biological ink, which is beneficial to maintaining the activity of the cells and improving 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 beneficial to reducing the impact of ultraviolet light on cell activity, but also beneficial to improving printing efficiency.

[0057] Ultrasonic vibration plates 19 are fixed to the outer walls of the liquid tank 17. These plates are connected to an ultrasonic generator 110, which in turn is connected to a controller. These plates are fixed to both sidewalls of the liquid tank 17 and ultrasonically mix the bio-ink and cell buffer within the tank 17. This real-time ultrasonic mixing of the bio-ink and cell buffer by the plates 19 reduces the difficulty of preserving the mixed bio-ink and cell buffer, enhancing cell viability. It also reduces cell sedimentation and improves the uniformity of the cell suspension, thereby increasing the uniformity of cell concentration within each printed layer and improving cell printing quality.

[0058] The interior of the liquid tank 17 is provided with a temperature sensor, a humidity sensor, a light intensity sensor and a cell concentration sensor electrically connected to the controller, which monitors the biological ink and cell buffer in the liquid tank 17 in real time, so that the suspension is maintained in an environment suitable for cell growth, which is beneficial to improving cell activity and printing quality, and improving cell culture effect.

[0059] An array of curing light sources 23 is installed within the electrical chamber 2, located directly below the liquid tank 17. An LCD screen 18 is mounted on the partition 14, allowing light from the curing light sources 23 to pass through. The liquid tank 17 is located directly above the LCD screen. A release film is placed between the bottom of the liquid chamber 122 and the LCD screen 18 to facilitate separation of the printed and cured biological structure from the LCD screen 18.

[0060] like Figure 6 As shown, the curing light source 23 includes a mounting base 27, which is fixed inside the electrical compartment 2. Inside the mounting base 27, a parallel array of curing lamps 28 is located. The curing lamps 28 are electrically connected to the controller. These UV lamps are arranged in an array, providing a continuous, stable, and evenly distributed UV light for the printing process. The UV light intensity and exposure time are controlled by the controller. Furthermore, the parallel array of UV curing lamps 28 facilitates maintenance and repair.

[0061] A controller controls the brightness of pixels on an LCD screen 18 to determine the light-transmitting portion of the screen, thereby solidifying a specific shape within the liquid tank 17. This allows for the printing of each layer, which, when stacked, forms a 3D bioprinted structure. The LCD screen 18 significantly improves printing accuracy and efficiency, mitigates the effects of ultraviolet light on cell activity, and reduces the cost of the photocuring 3D bioprinting device.

[0062] A printing platform 15 is provided above the liquid tank 17, and a lifting structure for driving the printing platform 15 to rise and fall is provided inside the cabin 11. The lifting structure includes a column 116, the bottom end of the column 116 is fixedly provided on the partition 14, and a screw rod 117 is provided on the column 116. The two ends of the screw rod 117 are rotatably connected to the column 116 through bearings. A motor 123 for driving the screw rod 117 to rotate is provided in the electrical room 2, and the motor 123 is connected to the controller. The printing platform 15 is fixedly provided on the connecting seat 118, and a nut compatible with the screw rod 117 is provided on the connecting seat 118. The screw rod 117 drives the connecting seat 118 up and down through the nut, thereby driving the printing platform 15 to gradually move up. The printing platform 15 drives the biological 3D printed product to gradually lift up, thereby realizing layer-by-layer printing of the printed product. The upright post 116 is fixed with a guide rail 119 that guides the sliding of the connecting seat 118. The guide rails 119 are located on both sides of the screw rod 117 and are arranged parallel to the screw rod 117. The connecting seat 118 is provided with a guide groove that matches the guide rail 119. The guide rail 119 is located in the guide groove and is slidably connected to the guide groove.

[0063] The chamber 11 is equipped with a thermostat 16, a liquid-adding mechanism, a lifting mechanism, and a curing light source 23, all of which are electrically connected to the controller. The thermostat 16 can be manually set or controlled by the controller to maintain the temperature within the printing chamber 1 at a level suitable for cell survival, thereby enhancing cell activity. The thermostat 16 is equipped with an air outlet, which adjusts the temperature and humidity within the printing chamber 1 simultaneously, maintaining the desired temperature and humidity within the printing chamber 1. This helps enhance cell activity and improves printing success rates.

[0064] A door 12 is hinged at one open end of the cabin 11, through which the liquid tank 17 in the cabin 11 can be cleaned, and the daily maintenance and repair of the internal components can be facilitated. An observation window 13 is provided on the cabin door 12. The transparent observation window 13 allows the staff to observe the printing process in the printing room 1. An ultraviolet sterilization lamp 114 and an illumination lamp 115 are provided inside the cabin 11. The ultraviolet sterilization lamp 114 is set at both ends of the top of the cabin 11 to sterilize the interior of the cabin 11 before the addition of biological ink and after the printing is completed, so that the cells are printed in a sterile environment, avoiding cross infection, which is beneficial to improving cell activity and also facilitates the sterilization of the interior of the cabin 11. The illumination lamp 115 is a warm light lamp tube, and the wavelength of the light will not affect the cells and photosensitive materials.

[0065] Electrical room 2 is equipped with a main power supply 24 and a temperature-controlled power supply 25. The main power supply 24 provides power for the entire device, while the temperature-controlled power supply 25 provides power for the thermostat 16. Both the main power supply 24 and the temperature-controlled power supply 25 are connected to the controller. A radiator 26 is located within electrical room 2. Heat dissipation holes 29 are provided on the housing 21 of electrical room 2. Radiator 26 faces heat dissipation holes 29 and dissipates heat within electrical room 2. Housing 21 is equipped with a touchscreen control screen 22, which allows users to select printing parameters and printing modes, and displays information such as temperature, humidity, and estimated completion time during the printing process.

[0066] The controller is equipped with an AI intelligent auxiliary system, which monitors and automatically adjusts key parameters such as temperature, humidity, and light intensity during the printing process, and provides feedback to adjust light curing time, liquid addition speed, ultrasonic vibration intensity, etc. to ensure printing quality and efficiency. The printing method of the above-mentioned LCD biological 3D printing device includes the following steps:

[0067] S1. Turn on the ultraviolet sterilization lamp 114 to disinfect and sterilize the cabin 11. Turn off the ultraviolet sterilization lamp 114 after the sterilization is completed.

[0068] S2. Select the printing mode through the control panel 22 and set the parameters of the printing mode.

[0069] S3, the liquid storage tube 111 adds a designed amount of bio-ink and cell buffer into the liquid tank 17 through the conduit 112, and 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, the motor 123 drives the screw rod 117 to rotate, and the screw rod 117 drives the printing platform 15 to descend through the connecting seat 118, and the printing platform 15 descends to the bottom of the liquid tank 17.

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

[0072] S6. The temperature sensor, humidity sensor, light sensor, and cell concentration sensor monitor the liquid in tank 17 and transmit these parameters to the controller, which adjusts the temperature, humidity, light intensity, and cell concentration in tank 17 in real time. Thermostat 16, under the control of the controller, maintains a constant operating temperature in printing chamber 1.

[0073] After printing is completed, the printed biological 3D printed product is taken out, the liquid tank 17 is cleaned, and the ultraviolet sterilization lamp 114 is turned on to sterilize the cabin 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; the historical measurement data includes: the temperature, humidity, light intensity, cell concentration and suspension uniformity of the liquid tank, as well as the amount of liquid added, 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 of each printing layer can be the same or different. The embodiment of the present invention takes the parameter adjustment of the current printing layer and the next printing layer as an example for explanation.

[0077] Specifically, historical measurement data for the current print layer is obtained from multiple dimensions, including environmental parameters, device status, and biological indicators. Environmental parameters include: tank temperature, humidity, and light intensity. The tank temperature can be obtained by a temperature sensor, preferably a thermocouple sensor; the tank humidity (i.e., the cabin humidity) can be obtained by a humidity sensor, preferably a capacitive humidity sensor; and the tank light intensity can be obtained by a light sensor, preferably a photosensor. Device status includes: motor displacement accuracy, liquid addition volume (liquid addition pump flow rate), and ultrasonic vibration frequency. Motor displacement accuracy can be obtained from feedback from an encoding unit within the controller; liquid addition volume can be obtained from a component that can calculate liquid flow, such as an electromagnetic flowmeter; and ultrasonic vibration frequency can be obtained from an ultrasonic generator, preferably an accelerometer. Biological indicators include: cell concentration and suspension uniformity. Cell concentration can be obtained by a cell concentration sensor, preferably an optical density sensor, and suspension uniformity can be analyzed using microscopic image analysis software.

[0078] S62. Preprocess and extract features from historical measurement data; features include: the temperature change rate of the liquid tank, the correlation coefficient between the amount of liquid added 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 and light time, the average light time, and the trend of success rate changes.

[0079] Among them, the extracted features are key features and can be used as inputs for the prediction model of the target LCD 3D bio-printing device.

[0080] Specifically, the features include multiple dimensions, which are divided into dynamic features, historical features and interactive features. Among them, the dynamic features include: the temperature change rate of the liquid tank, the correlation coefficient between the amount of liquid added and the cell concentration (i.e., the Pearson coefficient), and the influence index of the ultrasonic vibration frequency on the suspension uniformity. The interactive features include: the product of temperature and humidity (synergistic effect), the ratio of light intensity and illumination time. The historical features include: average illumination time, success rate change trend. Preferably, the average illumination time is preferably the average illumination time of the past five printing layers, and the success rate change trend is preferably the success rate trend of three consecutive prints.

[0081] S63. Inputting features with contribution greater than a first preset value into a target LCD 3D bio-printing device prediction model using a principal component analysis method to obtain prediction data for the next printing layer; the target LCD 3D bio-printing device prediction model is determined based on a multivariate regression algorithm sub-model and a random forest algorithm sub-model;

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

[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 multivariate regression algorithm sub-model and the random forest algorithm sub-model is used to perform predictions to obtain the predicted data of the next printing layer, such as: adjusted illumination time, liquid addition rate, etc.

[0085] S64, performing target loss function calculation on the predicted data of the next printing layer and the actual data of the next printing layer, adjusting parameters of the LCD biological 3D printing device according to the target loss function, and using the adjusted parameters for printing the next printing layer.

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

[0087] In an optional embodiment, an incremental learning module can be set up in the system to regularly add newly generated printing data (including success and failure cases) to the training set, and retrain the model to adapt to dynamic factors such as equipment aging and material batch differences.

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

[0089] Finally, the parameters of the LCD bio-3D printing device are adjusted based on the target loss function and used to print the next layer. These adjusted parameters can be transmitted to the printer's mechanical control structure to automatically adjust the light intensity, motor speed, and liquid dosage, preparing for the next layer.

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

[0091] Real-time controller adjustments also include:

[0092] Obtain microscopic imaging of the current printing layer;

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

[0094] When the reward function value is greater than a third preset value, the parameters of the current printing layer are readjusted after all layers are printed; the readjustment is completed by triggering an action instruction based on the reward function value corresponding to the microscopic imaging.

[0095] Specifically, filtering (noise reduction) involves applying Kalman filtering to temperature and ultrasonic vibration signals to eliminate mechanical interference during device operation. Time alignment (synchronization) involves aligning data with different sampling frequencies using timestamps, for example, aligning 1Hz temperature data with 10Hz ultrasonic vibration data. Normalization involves scaling each parameter in historical measurement data to the [0, 1] range, for example, linearly mapping temperature from 25°C to 45°C to prevent dimensionality from affecting model training.

[0096] Secondly, a reward function for imaging quality indicators is defined based on the reinforcement learning framework. The imaging quality indicators include cell survival rate, structural accuracy, and energy consumption. The specific reward function is:

[0097] R = 0.7 × cell survival rate + 0.2 × structural accuracy - 0.1 × energy consumption.

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

[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 of the real-time adjustment method of the controller of the present invention and the traditional printing method with fixed parameters, specifically including:

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

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

[0103] Evaluation indicators: 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) predicts the optimal lighting time and liquid addition rate for the next layer.

[0107] Input: The filtered 15-dimensional feature vector.

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

[0109] Loss function: mean square error (MSE) + printing success rate penalty.

[0110] Training parameter settings: use Adam optimizer, learning rate 0.001, batch size 32, and iteration 500 rounds.

[0111] 1.2. Reinforcement Learning Module:

[0112] State space: current environment parameters, device status, and number of printed layers.

[0113] Action space: a set of discrete actions (e.g., “increase exposure time by 5%”, “reduce vibration frequency by 10Hz”).

[0114] Reward function:

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

[0116] Algorithm: Deep Q-Network (DNQ), experience replay buffer capacity 1000, ε is the greedy strategy, ε=1.

[0117] 1.3 Training process:

[0118] In the initial stage, the supervised model is pre-trained using historical measurement data;

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

[0120] After each complete print, the DQN network weights are updated, prioritizing the replay of failed case data.

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

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

[0123] 2.1. Before printing each layer:

[0124] Each sensor collects real-time data and generates feature vectors.

[0125] The supervised model outputs parameter adjustment suggestions (e.g., adjusting the exposure time from 8s to 8.4s). The reinforcement learning module selects an action based on the current state (e.g., "slightly increase the amount of liquid added").

[0126] 2.2. After each layer is printed:

[0127] The optical microscopy system detects the quality of the current layer (edge ​​clarity, cell distribution); if an abnormality is detected (e.g., blurriness > 5%), parameter backtracking is triggered;

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

[0129] - Enable an alternative control strategy (such as fixed filling rate mode).

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

[0131] 3. Model iteration and verification

[0132] Incremental update: The model is retrained after every 50 printing tasks.

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

[0134] - Adopting the Elastic Weight Combining (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 adjusted parameters.

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

[0138]

[0139]

[0140] This method utilizes a data-driven deep learning framework to achieve adaptive optimization of printing parameters. From multidimensional data acquisition to hybrid model training and real-time closed-loop control, each step is tailored to the specific requirements of bioprinting (such as maintaining cell viability), ultimately surpassing traditional methods in efficiency, precision, and reliability.

[0141] Therefore, the LCD biological 3D printing device and printing method described in the present invention can solve the problems of poor activity and low precision of biological cells printed by existing 3D printing devices.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An LCD biological 3D printing device, characterized by: It includes a printing room and an electrical room. The electrical room is located below the printing room. A partition is provided at the bottom of the printing room to separate the printing room and the electrical room. A liquid tank is provided on the upper surface of the partition. A liquid adding structure for adding liquid into the liquid tank is provided on the cabin of the printing room. A printing platform is provided above the liquid tank. A lifting structure for driving the printing platform to rise and fall is provided inside the cabin. A temperature controller is provided inside the cabin. An array-type curing light source is provided in the electrical room. The curing light source is located directly below the liquid tank. An LCD screen is provided on the partition to allow the light of the curing light source to penetrate. The liquid adding structure, temperature controller, lifting structure and curing light source are all electrically connected to the controller.

2. The LCD biological 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 passed through the mounting holes to fix the liquid tank to the partition. A release film is provided between the bottom of the liquid cavity and the LCD screen. The liquid cavity is a stepped structure with a small bottom opening and a large top opening.

3. The LCD biological 3D printing device according to claim 1, characterized in that: An ultrasonic vibration plate is provided on the outer wall of the liquid tank, which is connected to an ultrasonic generator, which is connected to a controller. The ultrasonic vibration plate ultrasonically mixes the liquid in the liquid tank; a temperature sensor, a humidity sensor, a light intensity sensor and a cell concentration sensor electrically connected to the controller are provided inside the liquid tank.

4. The LCD biological 3D printing device according to claim 1, characterized in that: The liquid adding structure includes a liquid storage tube, which is fixedly arranged on the inner wall of the cabin. The two liquid storage tubes are filled with biological ink and cell buffer respectively. The liquid storage tubes are connected to the liquid tank through a catheter, and the biological ink and cell buffer are respectively injected into the liquid tank through the catheter.

5. The LCD biological 3D printing device according to claim 1, characterized in that: The lifting structure includes a column, the bottom end of the column is fixedly set on the partition, a screw is set on the column, the two ends of the screw are rotatably connected to the column, a motor for driving the screw to rotate is set in the electrical room, the motor is connected to the controller, the printing platform is set on the connecting seat, the connecting seat is provided with a nut adapted to the screw, and the column is provided with a guide rail that guides the sliding of the connecting seat.

6. The LCD biological 3D printing device according to claim 1, characterized in that: A door is hinged at one end of the opening of the cabin, which is provided with an observation window, and an ultraviolet sterilization lamp and a lighting lamp are provided inside the cabin; The curing light source comprises a fixing base which is fixed inside the electrical chamber. A parallel array of curing lamps is arranged inside the fixing base. The curing lamps are electrically connected to the controller.

7. The LCD biological 3D printing device according to claim 1, characterized in that: The electrical room is provided with a main power supply and a temperature-controlled power supply. The main power supply provides power output for the entire device, and the temperature-controlled power supply provides power output for the thermostat. Both the main power supply and the temperature-controlled power supply are connected to the controller. A radiator is provided inside the electrical room. Heat dissipation holes are provided on the shell of the electrical room. The radiator is opposite to the heat dissipation holes, and a control panel is provided on the shell.

8. A printing method based on the LCD biological 3D printing device according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Turn on the UV sterilization lamp to disinfect and sterilize the cabin. Turn off the UV sterilization lamp after sterilization is completed. S2. Select the printing mode through the control screen and set the parameters of the printing mode; S3. The liquid storage tube adds a designed amount of bio-ink and cell buffer into the liquid tank through the catheter. 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 screw to rotate, and the screw drives the printing platform to descend through the connecting seat, and 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 layer of the printed structure. The light-transmitting portion of the LCD screen is selected to solidify the photosensitive bio-ink in the liquid tank. The motor drives the printing platform to gradually rise through the screw and the connecting seat, and the printed structure is stacked layer by layer. S6, the temperature sensor, humidity sensor, light sensor and cell concentration sensor monitor the liquid in the tank and send the parameters to the controller, which adjusts the temperature, humidity, light intensity and cell concentration in the tank in real time; the thermostat maintains the working temperature of the printing chamber at a constant temperature under the action of the controller.

9. The printing method of the LCD biological 3D printing device according to claim 8, characterized in that: In S6, the real-time adjustment of the controller includes the following steps: S61, obtaining 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 tank, as well as liquid addition amount, ultrasonic vibration frequency, and motor displacement accuracy; S62. Preprocessing and feature extraction are performed on the historical measurement data; the features include: the temperature change rate of the liquid tank, the correlation coefficient between the amount of liquid added 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 time, the average light time, and the trend of success rate change; Preprocessing includes: filtering, time alignment, and normalization operations; S63. Inputting features with contribution greater than a first preset value into a target LCD 3D bio-printing device prediction model using a principal component analysis method to obtain prediction data for the next printing layer; the target LCD 3D bio-printing device prediction model is determined based on a multivariate regression algorithm sub-model and a random forest algorithm sub-model; S64, performing target loss function calculation on the predicted data of the next printing layer and the actual data of the next printing layer, adjusting parameters of the LCD biological 3D printing device according to the target loss function, and using the adjusted parameters for printing the next printing layer.

10. The printing method of the LCD biological 3D printing device according to claim 9, characterized in that: Real-time controller adjustments also include: Obtain microscopic imaging of the current printing layer; Determining a reward function value corresponding to the microscopic imaging according to an imaging quality index; When the reward function value is greater than a third preset value, the parameters of the current printing layer are readjusted after all layers are printed; the readjustment is completed by triggering an action instruction based on the reward function value corresponding to the microscopic imaging.

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