Large-scale biological 3D printing equipment and application thereof

Abstract

The invention discloses large-scale biological 3D printing equipment and application thereof. The large-scale biological 3D printing equipment is composed of a liquid inlet system, a printing platform, a storage system and a transmission control system. The conveying control system inputs a printing supporting plate into the printing platform from the storage system, the liquid inlet system is connected with the printing platform to provide production raw materials, the printing platform forms fibers on the printing supporting plate to obtain a finished product printing supporting plate, and the conveying control system outputs the finished product printing supporting plate to the storage system. And meanwhile, the transmission control system can continuously input the printing supporting plate to realize a continuous production mode. The equipment is based on the 3D printing technology, raw material supply, printing forming and product caching in production can be integrally achieved, through automatic control and batch printing, the production efficiency is improved, unattended large-scale production can be achieved, and the production efficiency is improved. And new printing equipment is provided for large-scale production of products such as cell culture meat, flexible electronics, food, buildings and the like.

Description

Technical Field

[0001] The present invention belongs to the field of biological 3D printing, and specifically relates to a large-scale biological 3D printing device and its application. Background Art

[0002] Bio-3D printing is an advanced technology that uses additive manufacturing principles to locate and assemble biomaterials or cell units driven by three-dimensional model instructions to construct tissue engineering scaffolds and tissue organs. Although existing commercial bio-3D printers are highly integrated and easy to operate, their high cost, simple structure, and difficult-to-replace extrusion nozzles limit their production flexibility and finished product complexity. Although the bio-3D printing equipment assembled by a liquid inlet pump, a 3D printer, and a customized extrusion nozzle is low-cost and can form fibers with complex structures, its low degree of integration makes the operation complex and time-consuming and labor-intensive. At the same time, none of the above-mentioned 3D bio-printing equipment takes into account batch printing and large-scale production, which limits its further application in the fields of cell cultured meat, flexible electronics, and food.

[0003] Cell cultured meat is a type of meat produced by in vitro culture of stem cells. Its emergence can solve the food safety and animal welfare issues in traditional meat production and effectively alleviate environmental pressure. With the help of biological 3D printing technology, the shape and gap size of cell cultured meat samples can be accurately adjusted, which has great potential in the construction of cell cultured meat tissue. However, its technical development cost is high, and the lack of core equipment for large-scale production is also the main difficulty that needs to be overcome in the future. Therefore, it is of great significance to develop a biological 3D printer that can achieve low-cost, batch, automated, convenient and efficient production and apply it to the large-scale production of cell cultured meat.

[0004] Purpose of the Invention

[0005] Invention content: In view of the problems existing in the prior art, the present invention provides a large-scale biological 3D printing device, which effectively solves the problems of the existing biological 3D printing production process, such as the large number of equipment required, high cost, low integration, complex operation, poor flexibility of the print head, low printing efficiency, and low automation. The present invention can be flexibly and conveniently applied to various printing pallets through the automatic leveling and variable pitch function of the extrusion channel, and can reduce the manufacturing requirements and costs of the extrusion channel and the printing pallet. The device of the present invention will further fill the gap of large-scale integrated production equipment in the production field of cell culture meat, and provide a reference solution for the large-scale production of flexible electronics, food, construction and other products.

[0006] The present invention also provides application of the large-scale biological 3D printing device.

[0007] Technical solution: To achieve the above object, a large-scale biological 3D printing device of the present invention is composed of a liquid inlet system, a printing platform, a storage system, a transmission control system, and a printing pallet; the transmission control system inputs the printing pallet from the storage box of the storage system into the printing platform, the liquid inlet system is connected to the printing platform to provide production raw materials, the printing platform forms printed products in batches on the printing pallet to obtain a finished printing pallet, and the transmission control system then outputs the finished printing pallet to the storage rack of the storage system. At the same time, the transmission control system can continue to input new printing pallets from the storage box of the storage system into the printing platform to achieve a continuous production mode.

[0008] Among them, the liquid inlet system includes m liquid inlet pumps, where m is an integer ≥ 1. The liquid inlet pump includes a motor-connected lead screw, an optical axis, an adjusting screw, a pressing plate, a motor base, a fixed seat, a pushing seat, a lead screw nut, and a motor; the motor-connected lead screw and the optical axis pass through both ends of the pushing seat and are connected to the fixed seat and the motor base. The lead screw nut inside the pushing seat can be disengaged from the motor-connected lead screw. The pressing plate is arranged on the surfaces of the pushing seat and the fixed seat, and the pressing plate can be locked by the adjusting screw; the motor is located below the motor base, and the lead screw nut is located inside the pushing seat; the injection device loaded by the liquid inlet pump is fixed in the groove of the fixed seat through the pressing plate and the adjusting screw. The motor-connected lead screw drives the pushing seat to reciprocate along the optical axis to realize the extraction and injection of the injection device, and the optical axis provides a guiding function for the movement of the pushing seat.

[0009] Among them, each of the m liquid inlet pumps is independently controlled. The number of grooves in the fixed seat is n, and a single liquid inlet pump can load 1 to n syringes at the same time. n is an integer ≥ 1. Different liquid inlet pumps can load different specifications of syringes, and m and n can be freely selected according to needs.

[0010] Preferably, m is 2 and n is 3.

[0011] Among them, the connection method between the motor and the motor-connected lead screw is one of coupling, gear transmission, synchronous belt transmission, chain transmission, and direct coupling. The motor-connected lead screw is one of trapezoidal lead screw, hydrostatic lead screw, and ball screw.

[0012] Preferably, the connection method between the motor and the motor-connected lead screw is synchronous belt transmission, and the motor-connected lead screw is a trapezoidal lead screw.

[0013] Among them, the printing platform includes a three-dimensional moving device and a printing nozzle; the three-dimensional moving device is connected to and drives the printing nozzle to move. The printing nozzle is provided with one or more extrusion channels, and can extrude printing materials on the printing pallet to stack and form; the extrusion channels can be fixed or freely installed, quickly disassembled and assembled on the printing nozzle, and their number can be freely adjusted according to needs, and the distance between them can be automatically changed according to needs.

[0014] Among them, the three-dimensional moving device structure is one of a gantry structure, a cantilever structure, a Makerbot structure, an Ultmaker structure, an Hbot structure, a Core XY structure, and a parallel arm structure.

[0015] Preferably, the three-dimensional moving device structure is an Ultmaker structure.

[0016] Among them, the single extrusion channel is equipped with a channel sensor, a platen sensor, a fixed slider, and an adjustment motor for automatically leveling each extrusion channel to adapt to different printing platens. The channel sensor can detect the bottom position of the extrusion channel; the platen sensor can detect the position of the printing platen below, and triggers the platen sensor when the printing platen moves from far to near to a set distance from the platen sensor; the extrusion channel is installed in the fixed slider; the adjustment motor is located behind the fixed slider and is used to control the up and down movement of the fixed slider, thereby driving the up and down movement of the extrusion channel; the channel sensor is one or more of a photoelectric sensor, a capacitive sensor, an inductive sensor, a pressure sensor, and a microswitch, and the platen sensor is one or more of a BL-touch, a photoelectric sensor, a capacitive sensor, an inductive sensor, a pressure sensor, and a microswitch.

[0017] Preferably, the channel sensor is a photoelectric sensor, and the platen sensor is a photoelectric sensor.

[0018] Furthermore, both the channel sensor and the platen sensor are fiber optic sensors.

[0019] Preferably, the extrusion channel is further equipped with a zeroing sensor, a mounting block, a horizontal motor, and a wire interface for realizing the quick disassembly and assembly and variable distance of the extrusion channel. The zeroing sensor is located on the left side of the extrusion channel for positioning the extrusion channel and is one of a photoelectric sensor, a capacitive sensor, an inductive sensor, a pressure sensor, and a microswitch; the mounting block is located behind the extrusion channel for connecting and disconnecting the extrusion channel and its accessories to the printing nozzle; the horizontal motor is located behind the extrusion channel for controlling the left and right movement and variable distance of the extrusion channel; the wire interface is located on the top of the extrusion channel for connecting each accessory of the extrusion channel to the control circuit.

[0020] Preferably, the zeroing sensor is a microswitch.

[0021] Among them, the extrusion channel can be connected to a syringe installed in the liquid inlet system through a catheter, or be externally connected to an air pump, a peristaltic pump, or be directly integrated with the liquid inlet system; the extrusion channel is one or more of a microfluidic chip, a pneumatic extrusion head, a piston extrusion head and a spiral extrusion head, which can be flexibly replaced; the extrusion channel can extrude the printing material to generate a solid type, a "shell-core" type, a spiral type, a multi-component type or a hollow type structure.

[0022] Preferably, the extrusion channel is connected to a syringe installed in a liquid inlet system through a catheter, and the extrusion channel is a microfluidic chip.

[0023] Preferably, the resulting structure is a "shell-core" structure.

[0024] Among them, the storage system includes a spare storage box, a finished product storage rack, a printing pallet, and a shell. The printing pallet includes a spare printing pallet to be printed and a finished product printing pallet after printing; the spare storage box stores the spare printing pallet to be printed, and the finished product storage rack stores the finished product printing pallet after printing; the printing pallet is used for the printing platform to undertake printing; the shell is used to fix the liquid inlet system, the printing platform, the spare storage box, the finished product storage rack and the transmission control system.

[0025] Wherein, the finished product storage rack is provided with one or more layers of brackets, on which the finished product printing pallets can be placed at intervals.

[0026] Preferably, the finished product storage rack is provided with 5 layers of brackets.

[0027] The housing is provided with a plurality of expansion interfaces, which can be used to install one or more of a USB flash drive, a limit switch, a photoelectric sensor, a heater, an ultraviolet lamp, a liquid storage tank, a camera, a fan, a mechanical arm, and an external host computer. Preferably, the housing expansion interface is used to install a USB flash drive and a photoelectric sensor.

[0028] Among them, the printing tray can be directly used for printing by the printing nozzle on its surface, or a plurality of grooves of different shapes are arranged on its surface according to the extrusion channel spacing to place a plurality of collecting containers of different specifications for the printing nozzle to undertake printing; the printing tray can be detachably connected to the three-dimensional mobile device by clamping, snapping, plugging, magnetic attraction, mortise and tenon, riveting, threading or bayonet; the printing tray material is one or more of polyvinyl chloride, polypropylene, polymethyl methacrylate, phenolic resin, polyethylene, polyformaldehyde, polyetheretherketone, polyethylene terephthalate, polycarbonate, acrylonitrile-butadiene-styrene copolymer, polylactic acid, glass, ceramics, wood, aluminum and its alloys, iron and its alloys.

[0029] Preferably, the printing pallet can be directly used for the printing nozzle to print on its surface, or multiple collecting vessels with different shapes are arranged according to the spacing of the extrusion channels to correspondingly place multiple collecting vessels with different specifications for receiving printing. The printing pallet is detachably connected to the three-dimensional moving device by magnetic attraction, and the material is PVC. The printing pallet can place multiple collecting vessels with different specifications to receive stacked fibers by arranging multiple grooves with different shapes according to the spacing of the extrusion channels.

[0030] Among them, the transmission control system includes a control panel, a conveyor, a linear mechanism, a controller, and a power supply; the control panel is connected to the controller, the power supply, the liquid inlet system, the printing platform, the conveyor, and the linear mechanism through wires to achieve overall control of the equipment; the controller and the power supply are installed inside the housing; the power supply supplies power to the control panel, the controller, the liquid inlet system, the printing platform, the conveyor, and the linear mechanism. The operator issues instructions through the control panel, and the control panel sends instruction information to the controller. The controller processes the instruction information and controls the actions of the liquid inlet system, the printing platform, the conveyor, and the linear mechanism according to the results; the conveyor is connected to the spare storage box, the printing platform, and the finished product storage rack, and is used to transport the spare printing pallet from the spare storage box to the printing platform and transport the finished printing pallet from the printing platform to the finished product storage rack. The linear mechanism is a support arm that can move up and down. The finished printing pallet can be transported from the conveyor to the support arm and used to transport the finished printing pallet to the bracket of the finished product storage rack.

[0031] Among them, the conveying method of the conveyor is one of belt conveying, chain conveying, roller conveying, screw conveying, and crank-rocker conveying.

[0032] Preferably, the conveying method of the conveyor is belt conveying.

[0033] The application of the large-scale biological 3D printing equipment described in the present invention in the large-scale production of cultured meat, tissues or organs, foods, flexible electronic materials, and building production materials.

[0034] The application described above includes the following steps:

[0035] (1) Place the required spare printing pallet in the spare storage box, draw the production raw material solution with a syringe, and fix the syringe in the liquid inlet system;

[0036] (2) Connect the syringe to the printing nozzle, and start and calibrate the equipment;

[0037] (3) Select the file to be printed, set the printing parameters, and start production;

[0038] (4) The conveyor inputs the printing pallet from the spare storage box to the middle position of the three-dimensional moving device. The printing nozzle is automatically leveled, and the product generated at the outlet of the extrusion channel is stacked layer by layer on the printing pallet and printed and cured according to the path generated by the printing file instructions.

[0039] (5) After the printing of a single spare printing pallet is completed, the conveyor outputs the finished printing pallet to the finished product storage rack, and the linear mechanism lifts the finished printing pallet and places it on the bracket.

[0040] (6) Repeat steps (4) and (5) automatically until the number of finished printing pallets is equal to the set number of printing pallets, and then take away the finished printing pallets from the finished product storage rack, and the production ends.

[0041] Among them, the process of the calibration device in step (2) is that the linear mechanism descends to the bottom to contact the shell, the lifting platform rises to separate the spare printing pallet from the conveyor, and the adjustment motor moves the extrusion channel until the bottom end of the extrusion channel is just recognized by the channel sensor; the printing file in step (3) is a device storage file, a U disk imported file or a file transmitted by an external host computer, and the printing parameters include one or more of the number of printing columns per pallet, the number of printing pallets, the printing spacing, the flow rate of the liquid inlet pump, the syringe specification, the heating temperature, the ultraviolet lamp parameters, the fan parameters, the robotic arm parameters, and the printing speed; steps (2) and (3) can be completed by the control panel or an external host computer; in step (4), the printing nozzle can directly print on the printing pallet, or a collection vessel can be placed on the printing pallet (5) through a robotic arm or manually for the printing nozzle to print; the curing method is one of chemical cross-linking curing, thermal curing, photo-curing, and drying curing.

[0042] Preferably, a culture dish is placed on the printing pallet manually by the printing nozzle for the printing nozzle to print; the curing method is chemical cross-linking curing; in step (4), the automatic leveling process is to move the printing pallet upward from the bottom until all pallet sensors are triggered, and the descending value of the inlet and outlet channels from the position recognized by the channel sensor is calculated according to the triggering time of each pallet sensor.

[0043] Preferably, the distance for moving the printing pallet upward from the bottom until all pallet sensors are triggered is 0 - 5 cm.

[0044] Among them, by changing the production raw material solution, it can be used for production in different fields, including bioink for cell culture meat, tissue or organ production, edible ink for food production, conductive ink for flexible electronics production, and concrete slurry for building material production.

[0045] Preferably, the application of the device in the large-scale production of cell culture meat includes the following steps:

[0046] (1) Place the required printing pallet in the spare storage box. Use a syringe to extract the production raw material solution such as cell suspension or bioink, and fix the syringe in the liquid inlet system.

[0047] (2) Connect the syringe to the printing nozzle, start and calibrate the equipment.

[0048] (3) Select the file to be printed, set the printing parameters, and start the production of cultured meat.

[0049] (4) The conveyor transports the printing pallet from the spare storage box into the three-dimensional moving device. The fibers generated at the outlet of the printing nozzle are stacked layer by layer on the printing pallet according to the path specified by the printing file instructions and solidified.

[0050] (5) When the printing of a single printing pallet is completed, the conveyor outputs the finished printing pallet to the finished product storage rack, and the lifting mechanism raises the finished printing pallet and places it on the bracket.

[0051] (6) Repeat steps (4) and (5) automatically until the number of finished printing pallets is equal to the set number of printing pallets. Take away the finished printing pallets from the finished product storage rack, and the production is completed.

[0052] The printing equipment of the present invention consists of a liquid inlet system, a printing platform, a storage device, and a transmission control system. The transmission control system transports the spare printing pallets from the storage device into the printing platform through the conveyor. The liquid inlet system is connected to the printing nozzle to provide production raw materials. The three-dimensional moving device drives the printing nozzle to form fibers in batches on the printing pallet to obtain the finished printing pallet. The conveyor then outputs the finished printing pallet to the finished product storage rack. At the same time, the conveyor can continue to input printing pallets to achieve continuous automated printing. Based on 3D printing technology, this equipment can integrate raw material supply, printing and forming, and product caching in the production of cultured meat. Through automated control and batch printing, it improves the production efficiency of cultured meat, enables unattended large-scale production of cultured meat, and provides a reference solution for the large-scale production of products such as flexible electronics, food, and architecture.

[0053] The present invention provides a large-scale biological 3D printing equipment. Based on 3D printing technology, this equipment can integrate raw material supply, printing and forming, and product caching in the production. Through automated control and batch printing, it improves the production efficiency, enables unattended large-scale production, and provides a new printing equipment for the large-scale production of products such as cultured meat, flexible electronics, food, and architecture. The 3D printing equipment in the present invention realizes the automatic leveling of the extrusion channel, and at the same time, the integration of the pump, printer, and transmission device is controlled through a touch screen as a whole, which is different from the stacking and separate control of external devices in the existing factory assembly line type; it effectively solves the problem that there is no specific production equipment for cultured meat on the market, and for biological printers, the functions of integrated automatic printing and transmission cannot be achieved.

[0054] At present, in actual work, due to the transparency, thinness and fragility of the capillary at the outlet of the microfluidic chip, it is difficult to identify and easy to break; large-scale production requires a larger printing pallet, and the increase and processing of the printing pallet will cause the printing positions of each channel to be uneven. It is difficult to detect the distance of a single point on the printing plane equivalent to the distance from the entire surface to each extrusion channel. There will also be errors in the installation of the printing platform and sensors; at the same time, due to manual production, the outlet lengths of the microfluidic chips are inconsistent, and the distance between the outlet of the microfluidic chip and the printing plane during printing significantly affects the printing result. For example, if the chip is too far from the printing plane, the generated fibers will not be able to contact the printing plane, resulting in poor forming of the finished product. If the chip is too close to the printing plane, the outlet of the chip will hit the printing plane during printing and break. The large-scale biological 3D printing device of the present invention realizes automatic leveling of the multi-channel microfluidic chip to meet the requirements of the automatic printing process of the device.

[0055] Existing 3D printers can easily achieve automatic leveling because the print head is fixed and rigid. However, for biological printers, since the print head and the printing plane are frequently replaced and there are various models, it is difficult to obtain a unified leveling parameter. At the same time, since it does not require batch printing, manual calibration before each printing can meet the requirements; for 3D biological printing devices that require batch and automatic working modes and the conditions of small and fragile microfluidic chips, a more precise and automatic leveling mode is needed. The printing device of the present invention is a modular production device. The print head structure is adjustable, flexible to replace and has a large number. It can perform multi-batch printing simultaneously, significantly improving the printing efficiency. In the present invention, each channel of the print head is relatively independent, and multiple sensors and motors are integrated and designed in the layout respectively, and can perform independent leveling movements, meeting the identification and leveling of different types of extrusion channels and printing pallets, reducing the operation difficulty of the operator and the requirements for the extrusion channels and printing pallets, and facilitating the realization of a stable automatic printing process. At the same time, by installing an electromagnet on the Z axis of the printing platform in the present invention, only by placing iron sheets at the four corners of the printing pallet, that is, the magnetic connection between the printing pallet and the printing platform, the rapid capture and release of the printing pallet can be achieved, reducing the structural complexity and cost of the printing platform.

[0056] Working principle of the present invention: 1. Place the printing pallet (5) into the spare storage box, extract the production raw material solution with a syringe (10), and install the syringe (10) in the liquid inlet pump (6) of the liquid inlet system (1); 2. Connect the syringe (10) and the extrusion channel (23) in the printing nozzle (22) through a conduit, turn on the device power supply, press the zero button on the control panel (41), and start device calibration, including the linear mechanism (43) descending to the bottom to contact the housing, the lifting table lifting (35), and the adjustment motor (24) driving the extrusion channel (23) installed on the fixed slider (27) until the bottom end of the extrusion channel is recognized by the channel sensor (25); 3. Select the file to be printed in the control panel (41), set the printing parameters, such as the number of printing columns per pallet, the number of printing pallets, the printing spacing, the flow rate of the liquid inlet pump, the syringe specification, the heating temperature, the ultraviolet lamp parameters, the fan parameters, the robotic arm parameters, and the printing speed, confirm and start production; 4. Lower the lifting table (35) to make the spare printing pallet (51) contact the conveyor. The conveyor (42) inputs the printing pallet from the spare storage box to the middle position of the three-dimensional moving device (21). The double z-axis moving arm (215) of the three-dimensional moving device (21) descends and uses the electromagnet (28) therein to adsorb the printing pallet (5). The 4 rectangular grooves on both sides of the printing pallet are used to place iron sheets for the Z-axis electromagnet (28) of the three-dimensional moving device (21) to adsorb. Through this design, the printing platform can quickly capture and release the printing pallet, improving work efficiency. The printing nozzle (22) performs automatic leveling. The liquid inlet pump (6) starts to work to provide the production raw material for the printing nozzle (22). The product generated at the outlet of the printing nozzle (22) is stacked and printed layer by layer on the printing pallet (51) according to the path generated by the printing file instructions and cured; 5. After a single printing pallet is printed, the finished printing pallet (52) is obtained. The double z-axis moving arm (215) of the three-dimensional moving device (21) descends to make the finished printing pallet (52) contact the conveyor (42). The electromagnet (28) is energized to demagnetize and lift the double z-axis moving arm (215). Start the conveyor (42) to transport the finished printing pallet to the linear mechanism (43) in the finished product storage rack (32). The linear mechanism lifts the finished printing pallet (52) to the uppermost bracket (38) that has not placed the finished printing pallet (52), and the linear mechanism (43) descends to the bottom; 6. Repeat steps (4) and (5) automatically until the number of finished printing pallets (52) is equal to the set number of printing pallets. Take away the finished printing pallet (52) from the finished product storage rack (32), and the production ends.Among them, the automatic leveling process in step (4) is as follows: The double z-axis moving arms move the printing pallet (5) from bottom to top until all pallet sensors (26) are triggered. The descent values of each extrusion channel (23) from the position recognized by the channel sensor (25) are calculated based on the triggering times of the respective pallet sensors (26). The motor (24) is adjusted to drive the fixed slider (27) equipped with the extrusion channel (23) to descend by the calculated descent value from the position recognized by the channel sensor (25).

[0057] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0058] (1) The large-scale biological 3D printing device developed by the present invention is used for the production of cultured meat and the like. It is convenient to operate, has rapid forming, high integration, and low cost of the required equipment and devices. The device can be controlled through a touch screen to complete printing, saving excessive equipment adjustment and coordination operation processes.

[0059] (2) The large-scale biological 3D printing device developed by the present invention has an adjustable printing head structure, can be flexibly replaced, and has a large number of printing heads, enabling multi-batch printing simultaneously, greatly improving the printing efficiency.

[0060] (3) The large-scale biological 3D printing device developed by the present invention has high programmability and user-friendliness. By integrating a transmission control system and a storage device, it can store spare printing pallets and automatically input and output printing pallets, realizing an unattended large-scale production mode for cultured meat.

[0061] (4) The large-scale biological 3D printing device developed by the present invention realizes automatic leveling of a multi-channel microfluidic chip to meet the requirements of the device's automated printing process, ensuring simultaneous identification during multi-batch printing and significantly improving the printing efficiency. Description of the Drawings

[0062] Figure 1 is an overall schematic diagram of the large-scale biological 3D printing device;

[0063] Figure 2 is a structural diagram of the liquid inlet system;

[0064] Figure 3 is a schematic diagram of the printing platform;

[0065] Figure 4 is a side view of the printing nozzle

[0066] Figure 5 is a schematic diagram of the storage device and the transmission control system;

[0067] Figure 6 is a schematic diagram of three printing pallets;

[0068] Figure 7It is a graphical user interface;

[0069] Figure 8 It is a printing plate setting interface;

[0070] Figure 9 It is a schematic diagram of a printing platform equipped with a high - level printing nozzle;

[0071] Figure 10 They are the front view and side view of a high - configuration extrusion channel;

[0072] Figure 11 It is a schematic diagram of variable pitch of a high - level printing nozzle;

[0073] Figure 12 It is a production result diagram of cell - cultured meat printed on a printing pallet;

[0074] Figure 13 It is a result diagram of cell - cultured meat in a culture dish placed on a printing pallet;

[0075] Figure 14 It is a bright - field view diagram of cell - cultured meat under a microscope;

[0076] Figure 15 It is a preparation result diagram of flexible electronics. Detailed implementation manners

[0077] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0078] The raw materials, reagents, etc. used in the embodiments are all commercially available. The seed cells are all obtained by existing conventional separation and purification methods or directly obtained commercially.

[0079] Embodiment 1

[0080] Construction of a large - scale biological 3D printing device

[0081] As Figure 1 shown, the device consists of a liquid inlet system 1, a printing platform 2, a storage device 3, and a transmission control system 4; the transmission control system 1 inputs the printing pallet 5 from the spare storage box 31 of the storage system 3 into the printing platform 2, the liquid inlet system 1 is connected to the printing platform 2 to provide raw materials for cell - cultured meat production, the printing platform 2 forms cell - cultured meat in batches on the printing pallet 5 to obtain a finished printing pallet 52, and the transmission control system 4 then outputs the finished printing pallet 52 to the finished product storage rack 32 of the storage system 3. At the same time, the transmission control system 4 can continue to input the printing pallet 5 into the printing platform 2 to achieve a continuous production mode.

[0082] As Figure 2As shown in the figure, the liquid inlet system includes two independent liquid inlet pumps 6, which are installed on the outer top of the housing of the spare storage tank 31. Each liquid inlet pump consists of a motor-connected lead screw 11, a smooth shaft 12, an adjusting screw 13, a pressing plate 14, a motor base 15, a fixing base 16, a pushing base 17, a lead screw nut 18, and an electrode 19. Among them, the lead screw nut 18 is locked and fixed in the pushing base 17 to form a detachable meshing with the lead screw 11. The motor 19 and the motor-connected lead screw 11 are fixed with synchronous pulleys and connected by a synchronous belt. The motor 19 is located below the motor base 15 and is fixed to the inner side of the outer shell 33 through the motor base 15. The pushing base 17, the fixing base 16, and the motor base 15 are connected by the motor-connected lead screw 11 and the smooth shaft 12. The motor drives the lead screw 11 to drive the pushing base 17 to move back and forth along the direction of the smooth shaft. The top of the fixing base 16 is provided with three grooves adapted to conventional injection devices 10 such as syringes. The syringe is placed in the groove of the fixing base 16. The fixing base 16 and the pushing base 17 are provided with through holes for the installation of the pressing plate 14, and the pressing plate 14 is fixed by a threaded hole for the adjusting screw 13. The syringe is fixed by the pressing plate 14, so that the movement of the pushing base 17 drives the extraction and injection of the syringe. Among them, the motor-connected lead screw 11 is a trapezoidal lead screw.

[0083] As Figure 3 and Figure 4, the printing platform consists of a three-dimensional moving device 21 and a printing nozzle 22. The printing nozzle 22 is connected to the x-axis moving arm 211 of the three-dimensional moving device 21 through a fixed slider 216. By disassembling and installing the fixed slider 216, the free replacement of the printing nozzle can be achieved. The x-axis moving arm 211 and the y-axis moving arm 212 of the three-dimensional moving device 21 control the movement of the printing nozzle in the horizontal plane. The Z-axis 215 is loaded with an electromagnet 28, which can adsorb and release the printing tray 5 and drive the printing tray 5 to move in the vertical direction. The structure of the three-dimensional moving device 21 is the Ultmaker structure. The printing nozzle 22 is provided with 3 extrusion channels 23, and each extrusion channel 23 is a microfluidic chip, which is fixed on the 3 fixed sliders 27 of the printing nozzle 22 by pressing. The fixed slider 27 is independently controlled by an adjustment motor 24 in the printing nozzle 22 to move up and down, thereby realizing the up and down movement of the microfluidic chip. There are 3 groups of sensors in the printing nozzle 22 corresponding to 3 extrusion channels 23. Each single extrusion channel 23 is equipped with a channel sensor 25, a tray sensor 26, a fixed slider 27, a pair of elastic pieces 29, and an adjustment motor 24, which are used for automatic leveling of each extrusion channel 23 to adapt to different printing trays 5. The channel sensor 25 can detect the bottom position of the extrusion channel 23, and the tray sensor 26 can detect the position of the lower printing tray 5. The extrusion channel 23 is installed in the fixed slider 27, and the adjustment motor 24 is used to control the up and down movement of the fixed slider 27. The elastic piece 29 is used to press the extrusion channel 23 in the fixed slider 27. Each group of sensors includes an optically fiber sensor (channel sensor) placed horizontally for identifying the outlet position of the microfluidic chip and an optically fiber sensor (tray sensor) placed vertically downward for identifying the position of the printing tray. When printing using a petri dish, the petri dish has a relatively high outer edge. The rest of the sensors need to extend a long distance from the bottom of the printing nozzle, which affects the printing range, or their accuracy is relatively low and difficult to meet the requirements. Therefore, optically fiber sensors are used here. The trigger threshold of the horizontally placed optically fiber sensor is set to the lowest value, that is, it is triggered once an object is in its optical path; the trigger threshold of the vertically placed optically fiber sensor is set to be triggered when the printing tray 5 moves from far to near to a distance of 2 cm from the optically fiber sensor. According to the above connection and assembly method, the number of extrusion channels is set to 4 to obtain the printing nozzle No. 2.

[0084] As Figure 5As shown in the figure, the storage system includes a spare storage box 31, a finished product storage rack 32, a printing pallet 5, and a housing 33. The spare storage box 31 stores the spare printing pallets 51 for printing. The finished product storage rack 32 stores the finished printing pallets 52 after printing. The printing pallet 5 is used for the printing platform 3 to undertake printing. The housing 33 is used to fix the liquid inlet system 1, the printing platform 3, the spare storage box 31, the finished product storage rack 32, and the transmission control system 4. The transmission control system includes a control panel 41, a conveyor 42, a linear mechanism 43, a controller, and a power supply. The control panel 41 is connected to the controller, the power supply, the liquid inlet system 1, the printing platform 2, the conveyor 42, and the linear mechanism 43 through wires to achieve overall control of the equipment. The finished product storage rack 32 is provided with 5 groups of brackets 38 arranged at intervals for placing the printing pallets. The conveyor 42 is a belt conveyor connecting the spare storage box 31, the printing platform 2, and the finished product storage rack 32, and is used to transport the spare printing pallets from the spare storage box 31 to the printing platform 2 and transport the finished printing pallets from the printing platform 2 to the finished product storage rack 32. The linear mechanism 43 is used to transport the finished printing pallets and place them on the brackets 38. The bottom of the spare storage box 31 is provided with a lifting platform 35, which can be lifted to make the stacked spare printing pallets 51 leave the conveyor 42 and lowered to make them contact the conveyor 42. A baffle 36 is provided at the outlet of the spare storage box 31, and its size is set so that only one printing pallet can pass through at a time. Anti-deviation strips 37 are arranged on both sides of the conveyor 42 to prevent the pallet from deviating during transportation. The finished product storage rack is provided with 5 brackets 38 as one-way hinges. After the printing pallet is transported to the linear mechanism, the linear mechanism only needs to rise and fall to place the printing pallet on the bracket 38. Three expansion interfaces 39 are provided on the housing, and a USB flash drive and a photoelectric sensor can be installed. The USB flash drive stores the printing files, and the photoelectric sensor is used to identify the position of the printing pallet. The above design realizes the integrated storage and input / output of the spare printing pallets, saves space, improves stability, and reduces costs.

[0085] As Figure 6 shown, the printing pallet is a rigid PVC board with a size of 30*35 cm and a thickness of 6 mm. The No. 1 printing pallet 53 has no surface treatment. The surface of the No. 2 printing pallet 54 is provided with 6 circular grooves 56, which can hold 6 circular culture dishes for printing. The No. 3 printing pallet 55 is provided with 3 square grooves 57, which can hold 3 cell culture plates for printing. Four rectangular grooves 58 are provided at the two side edges of the printing pallet for placing iron sheets 59, which are adsorbed by the Z-axis electromagnet 28 of the three-dimensional moving device 21. Through this design, the printing platform can quickly capture and release the printing pallet, improving work efficiency.

[0086] Embodiment 2

[0087] Development of the control panel graphical user interface

[0088] Based on the device of Embodiment 1, a touch screen graphical user interface and a host computer graphical user interface are developed for convenient control of the microfluidic 3D printing device, such as Figure 7 , Figure 8 .

[0089] The touch screen graphical user interface is developed by USART HMI software, including: power-on interface 61, main interface 62, printing mode interface 63, model library interface 64, custom interface 65, debugging interface 66, injection configuration interface 67, printing interface 68, setting interface 69, printing plate setting interface Figure 8 .

[0090] After the device is powered on, the touch screen enters the power-on interface 61 and enters the main interface 62 after waiting for the initialization of the preset parameters inside the device, such as the print head position, model library file detection, and syringe specification import to be completed. The main interface includes printing and setting buttons.

[0091] Press the setting button to enter the setting interface 69, where the screen brightness and volume can be set, and a custom syringe can be added to the injection configuration interface 67 by entering the syringe name and inner diameter and written into the memory.

[0092] After pressing the printing button, enter the printing mode interface 63. After pressing the setting button, enter the setting interface 69. In the printing mode interface, after pressing the model library or custom button, the single-chip microcomputer will detect whether a USB flash drive is recognized. If the USB flash drive is not inserted, an alarm will be given. If the USB flash drive is inserted, the corresponding model library interface or custom interface will be entered.

[0093] The model library interface 64 contains model parameter setting options (shape, size, line spacing, number of layers) for selecting different preset printing files in the model library. The current interface after changing the parameters will display a model preview picture, and the number of printing queues and the number of printing plates to be printed can be set in this interface. The shapes include rectangle and circle, the sizes include rectangle 10*10mm, 10*20mm, 15*30mm, 20*20mm, 30*30mm, circle 10mm, 15mm, 20mm, 25mm, etc., the line spacings include 1mm, 2mm, 3mm, 4mm, 5mm, and the number of layers includes 1 layer, 2 layers, 3 layers to 10 layers, which are set according to specific needs. After setting, click √ to read the file and start printing, and at the same time enter the printing plate setting interface( Figure 8 ).

[0094] The custom interface 65 displays the files in the user folder of the inserted USB flash drive (text type files such as.gcode and.txt). Slide and select the text box to select the required printing file. The number of printing queues and the number of printing plates to be printed can be set in this interface. After selection, click the OK and start printing buttons in sequence to read the file and start printing, and at the same time enter the printing plate setting interface(Figure 8 )。

[0095] Printing plate setting interface ( Figure 8 ) is used to set the printing pallet used, including three options: empty plate corresponding to No. 1 printing plate 53, round dish corresponding to No. 2 printing plate 54, and cell plate corresponding to No. 3 printing plate 55. For the empty plate, the corresponding spacing and printing groups can be set. The default spacing for the round dish and the cell plate is 97.5 mm, and the default number of printing groups is 2. After selecting the printing plate type, set the number of printing sheets, and click √ to enter the injection configuration interface 67.

[0096] The injection configuration interface 67 is used to set the syringe specifications and flow rates. The syringe specifications include standard syringes "1 mL", "2.5 mL", "3 mL", "5 mL", "10 mL", "20 mL", "30 mL", and the custom syringe specifications are imported at startup. The delete custom key is used to delete the custom syringe specifications from the memory. The injection pumps set can be switched to No. 1 and No. 2 through the ① and ② buttons at the top. After setting, click the arrow button in the lower right corner to enter the debugging interface 66.

[0097] The debugging interface 66 is used to control the movement and zeroing of the three-dimensional moving device and the overall calibration of the printer. It includes 6 xyz moving buttons, precision selection buttons, three-axis zeroing and single-axis zeroing buttons, return button, plate input button, device calibration button, and chip zeroing button. At the same time, the movement of the liquid inlet pump can be independently controlled through this interface. The moving buttons can respectively control the positive and negative movements of each axis. The precision selection button is used to control the moving distance of a single click of the moving button (0.1 mm, 1 mm, 10 mm). The three-axis zeroing button can control the three-axis position to move to zero, and the single-axis zeroing button can move the corresponding axis to zero. The return button is used to return to the previous interface. The zero points of the x-axis and y-axis are at the x-axis zeroing switch 213 and the y-axis zeroing switch 214 respectively. Click the "√" button in the lower right corner to start the printing work and enter the printing interface 68.

[0098] The printing interface 68 displays the printing file name, printing progress, and printing time, and includes continue / pause, stop, and printing debug buttons, which are used to control continue, pause, stop, and jump to the debug interface during the printing process respectively.

[0099] Example 3

[0100] Preparation of microfluidic chip, solution preparation, syringe installation

[0101] Preparation of microfluidic chip:

[0102] The microfluidic chip is composed of a glass capillary, a dispensing needle, and a glass slide. A cylindrical glass capillary with an inner diameter of 580 μm and an outer diameter of 1000 μm is selected, and the outlet is pulled to 200 μm as the outer phase channel; another cylindrical glass capillary with an inner diameter of 580 μm and an outer diameter of 1000 μm is selected, and the outlet is pulled to an inner diameter of about 80 μm as the inner phase channel; the two glass capillaries are coaxial and the outlet end faces are perpendicular to the capillary central axis, and the entire microfluidic channel should maintain symmetry. A 20G dispensing needle is fixed at the joint of the channels as the liquid inlet.

[0103] Syringe installation

[0104] After the syringe is filled with the liquid required for printing, it is fixed to the liquid inlet pump. Loosen the first adjustment screw 131, the second adjustment screw 132, and the third adjustment screw 133, pull out the first pressing plate 141, the second pressing plate 142, and rotate the third pressing plate 143; loosen the lead screw nut 18 to disconnect the lead screw nut 18 from the motor connecting lead screw 11; place the syringe in the groove of the fixing seat 16, with the rear flange 101 of the syringe placed between the driving seat 17 and the first pressing plate 141, and the front flange 102 pressing plate of the syringe placed between the fixing seat 14 and the second pressing plate 142. Adjust the first pressing plate 141, the second pressing plate 142, and the driving seat 17 to fix the syringe, tighten the first adjustment screw 131 and the second adjustment screw 132, rotate the third pressing plate 143 above the syringe, vertically press down the third pressing plate 143, and tighten the third adjustment screw 133. The syringe installation is completed.

[0105] Microfluidic chip installation: Connect the outlet end of the syringe to a 20G dispensing needle, take a polyethylene plastic tube to connect the dispensing needle with the inlet dispensing needle of the microfluidic chip and the inlet end of the inner phase capillary. Insert the microfluidic chip into and fix it in the inner opening of the slider 27, and press it tightly through the elastic piece 29 on the fixed slider. The installation is completed.

[0106] Solution preparation

[0107] Preparation of the outer phase fluid of the microfluidic chip: Take an appropriate amount of sodium alginate powder and sterilize it by ultraviolet irradiation overnight. Take 50 mL of sterile water in a centrifuge tube, weigh 1.5 g of sodium alginate powder and pour it into the centrifuge tube, mix it evenly using a vortex mixer, and then place the centrifuge tube in a 37 °C constant temperature water bath. After the sodium alginate powder is completely dissolved, a 30 mg / mL sodium alginate solution is prepared for standby.

[0108] Preparation of the internal phase fluid in the microfluidic chip: Dissolve 0.2 g of calcium chloride in 10 mL of DMEM basal medium containing phenol red (C11995500CP, Gibco) to obtain a DMEM solution containing 20 mg / mL of calcium chloride. Filter and sterilize it with a 0.22-μm filter membrane and store it on ice for later use. Weigh 0.4 g of NaOH into a centrifuge tube, add 10 mL of ultrapure water to dissolve it to obtain a 1 mol / L NaOH solution. After filtering and sterilizing it with a 0.22-μm filter membrane, store it on ice for later use. Taking 1 mL of the internal phase fluid system as an example, take a cell suspension of 2×10 7 porcine muscle stem cells into a centrifuge tube, centrifuge at 300×g for 5 min, remove the supernatant, and store the cell pellet on ice for later use. Resuspend 2×10 7 porcine muscle stem cells with 400 μL of the DMEM solution containing 20 mg / mL of calcium chloride. After adding 800 μL of 6 mg / mL collagen to the cell suspension, transfer the whole to a centrifuge tube containing 4 μL of 1 mol / L NaOH solution, then add 130 μL of Matrigel (standard type, Corning reagent company), gently pipette and mix well. Finally, store the obtained hydrogel solution on ice for later use.

[0109] Example 4

[0110] Equipment calibration, chip zeroing

[0111] Equipment calibration: Move each axis of the three-dimensional moving device to the zero point, and move the lifting mechanism to the lowest position.

[0112] Chip zeroing before printing: After the microfluidic chip is installed, start the zeroing program through the touch screen. At this time, the adjustment motor 24 is started to drive the fixed slider 27 to move downward. During the movement, once the channel sensor 25 detects the chip outlet end, the adjustment motor stops. Start the zeroing of the three-dimensional moving device. The x-axis moving arm 211 and the y-axis moving arm 212 move to the initial ends and touch the x-axis zeroing switch 213 and the y-axis zeroing switch 214 respectively. The double z-axis moving arm 215 rises until it triggers the selected channel corresponding tray sensor 26 and stops. Set this position as the z-axis zero point.

[0113] In actual work, due to the transparency, thinness, and fragility of the capillary at the outlet of the microfluidic chip, it is difficult to identify and easy to break; large-scale production requires a larger printing pallet, and the increase and processing of the printing pallet will cause the printing positions of each channel to be uneven, making it difficult to detect the distance of a single point on the printing plane equivalent to the distance from the entire surface to each extrusion channel; at the same time, the inconsistent outlet length of the microfluidic chip due to manual chip making, and the distance between the outlet of the microfluidic chip and the printing plane during printing significantly affects the printing result. Therefore, the following solutions are adopted to achieve automatic leveling of the multi-channel microfluidic chip to meet the requirements of the automatic printing process of the equipment (the bio-3D printers on the market are manually leveled and calibrated):

[0114] Automatic leveling of the chip before printing:

[0115] 1. Chip position identification: Each extrusion channel 23 moves the fixed slider 27 with the microfluidic chip downwards from top to bottom through the adjustment motor 24 in the printing nozzle; there is no residual fiber or solution at the outlet of the microfluidic chip before printing. When the outlet of the microfluidic chip moves to the position of the horizontal fiber optic sensor 25, the signal slider stops. At this time, the position of each microfluidic chip outlet is the installation position a of the horizontal fiber optic sensor 25.

[0116] 2. Determination of the zero position of the z-axis of the printing platform: The double z-axis moving arm 215 drives the printing pallet 5 to approach the printing nozzle from bottom to top at a speed of 1 cm / s. The fiber optic sensor 27 of each extrusion channel 23 triggers a signal when the printing pallet below it is 2 cm away from itself. In actual work, theoretically, the 3 vertical fiber optic sensors 26 should be triggered simultaneously, but due to errors in sensor installation, printing pallet processing, and its capture position, the triggering times of each fiber optic are different. After all 3 fiber optic sensors are triggered, the double z-axis moving arm stops moving. At this time, the position of the printing pallet 5 is the zero point of the z-axis of the printing platform 2.

[0117] 3. Determination of the chip extension length: The moving speed of the slider is 1 cm / s. In step 2, the zero position of the z-axis is determined by the last triggered fiber optic sensor 26. Therefore, the extrusion channel 23 of this fiber optic sensor 26 is set as the reference extrusion channel, that is, the distance between the fiber optic sensor 26 below it and the printing pallet below is exactly 2 cm. The time difference between the triggering of the fiber optic sensors 26 of the remaining channels and the reference channel is dt. The value of the chip descent from a of this channel is obtained as 2 - (1×dt) cm, and the descent value of the reference channel is 2 cm.

[0118] Through the above steps, automatic leveling of the multi-channel microfluidic chip can be achieved and it is applicable to uneven printing planes, providing a basis for subsequent large-scale production.

[0119] Chip zeroing when switching columns and printing pallets during printing:

[0120] Since printing has already started, there will be residual droplets or fibers at the outlet of the chip at this time, which will affect the recognition of the fiber optic sensor 25. The following solution is adopted: At this time, each chip has been leveled before printing and is in a suitable position. Adjust the motor 24 to drive the fixed slider 27 to rise by 0.5 cm. The printing nozzle moves to the x-axis and y-axis positions for the next printing. At this time, perform steps 2 and 3 of the automatic leveling before printing, and each channel obtains a new chip descent value x2. The chip descent value obtained from the previous leveling is x1. Control the adjustment motor 24 to make the fixed slider 27 descend by x1 - x2 + 0.5 cm. At this time, the chip is in a new suitable position.

[0121] Example 5

[0122] Construction of the high-level printing nozzle 7 with a high-level extrusion channel that can freely vary the pitch and be quickly disassembled and assembled. Compared with Example 1, its extrusion channel is still a microfluidic chip, and the functional components required for automatic leveling of the chip are the same. The difference is that other components are added to enable quick disassembly and pitch variation.

[0123] As Figures 9 - 11 shown, taking 4 extrusion channels as an example:

[0124] The high-level printing nozzle 7 is composed of 4 high-level extrusion channels 23 and a channel support 72. The channel support includes a rack 81, a guide groove 82, and a baffle 83. On the basis of one channel sensor 25, one pallet sensor 26, one fixed slider 27, a pair of elastic pieces 29, and one adjustment motor 24 equipped in the extrusion channel 23 in Example 1, the high-level extrusion channel 23 is additionally equipped with a zeroing sensor 91, a mounting block 92, a horizontal motor 93, and a wire interface 94. Among them, the high-level extrusion channel 23 and its components are connected to the guide groove 82 of the channel support 72 through the mounting block 92; the output shaft of the horizontal motor 93 is provided with a gear 931. When the high-level extrusion channel is installed on the channel support 72, the gear 931 meshes with the rack 81, and the horizontal motor 93 can drive the high-level extrusion channel 23 to move left and right along the guide groove 82. The baffle 83 is used to limit the position of the high-level extrusion channel 23 to prevent it from falling out of the channel support 72. The zeroing sensor 91 is located on the left side of the high-level extrusion channel 23 and is a micro switch that generates a signal when touched, and is used for positioning the high-level extrusion channel 23. The wire interface 94 is located at the rear upper part of the high-level extrusion channel 23 and is used to connect the control circuit. From left to right are the 1st channel 101, the 2nd channel 102, the 3rd channel 103, and the 4th channel 104.

[0125] Quick disassembly and assembly of the high-level extrusion channel:

[0126] Installation: Connect the control circuit to the wire interface 94, insert the gear 931 into the rack 81, and insert the mounting block 92 into the guide groove 82 to complete the quick installation of the high-end extrusion channel 23. Disassembly: Pull out the control circuit from the wire interface 94, pinch the bottom of the high-end extrusion channel 23 and apply force to disengage the gear 931 from the rack 81 and the mounting block from the guide groove 81 to achieve the disassembly of the high-end extrusion channel.

[0127] Automatic variable pitch of high-end extrusion channel:

[0128] like Figure 11 As shown, zeroing: the horizontal motor 93 drives channel 101 to move toward the baffle 83, the zeroing sensor 91 stops after being triggered, and starts to move left to channel 2 102, and so on. When moving to position ①, all four zeroing sensors 91 are triggered, and it is in the zeroing state. With the baffle position at 0, the width of a single high-end extrusion channel 23 is 4cm, so the position of channel 101 is 4cm, the position of channel 202 is 8cm, the position of channel 3 103 is 12cm, and the position of channel 4 104 is 16cm.

[0129] Distance change: Channel 4 104, Channel 3 103, Channel 2 102, and Channel 1 101 move in sequence. Channel 4 104 moves to 16+x1+x2+x3+x4 cm, Channel 3 103 moves to 12+x1+x2+x3 cm, Channel 2 102 moves to 8+x1+x2 cm, and Channel 1 101 moves to 4+x1 cm. At this time, the distance between Channel 1 101 and baffle 83 is x1, the distance between Channel 2 102 and Channel 1 101 is x2, the distance between Channel 3 103 and Channel 2 102 is x3, and the distance between Channel 4 103 and Channel 3 103 is x4.

[0130] This design can improve the utilization rate of the liquid inlet pump. For example, two three-channel liquid inlet pumps can supply liquid to a maximum of six extrusion channels. At this time, the number of extrusion channels can be quickly increased to improve printing efficiency. At the same time, the variable pitch function of the extrusion nozzle can more flexibly meet the printing requirements of different printing boards. For example, when four extrusion channels are installed, they can be printed in the printing board 53 at equal intervals. When switching to the printing board 54, three of the extrusion channels can be variable pitched to a mutual spacing of 97.5 cm to meet the printing requirements of the printing board 54. This design greatly increases the flexibility, freedom and convenience of printing.

[0131] Example 6

[0132] Large-scale production of cell-cultured meat

[0133] Printing was performed using the equipment of Example 1, using print head No. 2 (4 extrusion channels), and using print pallet No. 1 for receiving.

[0134] Use Solidworks software to create a printing model. The model is a cuboid with dimensions of 12 * 12 * 0.5 mm. Save the model in.stl format and export it. Import the.stl file into Cura software for slicing. Set the slicing parameters as follows: line spacing 0.4 mm, printing speed 15 mm / s. Perform slicing, save the generated.gcode file after slicing to a USB drive, and insert it into the shell for standby.

[0135] Start the device and begin the production of cultured meat. The steps are as follows:

[0136] (1) Place 5 printing pallets in the storage device. Use 4 5-mL syringes to extract the outer phase solution in Example 3 and install them in the liquid inlet pump 1. Use another 4 5-mL syringes to extract the inner phase solution in Example 3 and install them in the liquid inlet pump 2. The front and rear liquid inlet systems in Figure 1 can be referred to.

[0137] (2) Take 4 microfluidic chips prepared in Example 3. Connect the syringes to the microfluidic chips through conduits. Two syringes correspond to one microfluidic chip. Connect the syringe containing the inner phase solution to the inner phase of the microfluidic chip and the syringe containing the outer phase solution to the outer phase of the microfluidic chip. Fix the chip on the printing nozzle. Push the syringe through the touch screen to make the solution enter the microfluidic chip, and perform zero calibration on the microfluidic chip, three-dimensional moving device, and lifting mechanism according to Example 4.

[0138] (3) Select the sliced printing file. Set the syringe specifications of the No. 1 and No. 2 liquid inlet pumps to 5 mL, the flow rate of the No. 1 liquid inlet pump to 1.9 mL / h, the flow rate of the No. 2 liquid inlet pump to 1.8 mL / h, the printing pallet type to an empty plate, the number of printing columns to 4, the number of printing pallets to 5, and the printing spacing to 20 mm. Start the production of cultured meat.

[0139] (5) The conveyor transports the printing pallet from the storage device into the three-dimensional moving device. The Z-axis of the three-dimensional moving device descends and adsorbs the printing pallet. Fibers are generated at the outlet of the printing nozzle and stacked and solidified layer by layer on the printing pallet according to the path specified by the printing file instruction.

[0140] (6) After the single-column printing is completed, the printing nozzle moves to the next column position to continue printing until 3 columns are set. The printing of a single printing pallet is completed, as shown in Figure 6 . The Z-axis of the three-dimensional moving device descends to 3 cm above the conveyor. The electromagnet is energized and demagnetized, and the printing pallet falls on the conveyor. The conveyor transports the finished printing pallet to the lifting mechanism, and the lifting mechanism raises the finished printing pallet and places it in the card slot. The lifting mechanism descends and returns to its original position.

[0141] (7) Repeat the automatic execution of steps (5) and (6) until the number of finished product printing pallets is equal to the set number of printing pallets, then remove the finished product printing pallets and the production ends.

[0142] Among them, step (3) is completed on the control panel (41); in step 5, the internal and external phase solutions are introduced into the microfluidic chip for crosslinking and curing to form fibers with a "shell-core" structure.

[0143] As Figure 12 shown, 16 pieces of cultured meat can be printed on a single printing pallet, which improves the production efficiency and utilization rate. The technical effects of the present invention are described in detail in combination with experiments as follows: The manual preparation time before each production is about 230 s, the time required for printing a single model is 200 s, the time required for leveling before printing with a new pallet is 20 s, and the time required to release the printing plate and capture the second printing plate is 10 s. The time required for a conventional single-channel to print a plate is 16 * 200 + 60 + 230 + 20 = 3510 s, and after replacing with a 4-channel, the time is 4 * 200 + 230 = 1050 s, and the efficiency is 3.34 times; when there is no transmission control system, the time for a 4-channel to print 5 plates is (4 * 200 + 230 + 20) * 5 = 5250 s, and after adding the transmission control system, the total time after eliminating the manual preparation time for each pallet change is (4 * 200 + 10 + 20) = 4150 s, and the efficiency is increased by 1.27 times. At the same time, before adding the transmission control system, it is necessary to manually perform harvesting and preparation operations on time every 17.5 min, while after adding the transmission control system, it is only necessary to wait for 69 min after starting the preparation to directly harvest 5 printing pallets, which greatly reduces the frequency of manual intervention. At the same time, as the printing demand increases, the efficiency and convenience will also increase.

[0144] Use the No. 2 pallet and the printing nozzle with 3 extrusion channels in Example 1, load a circular 10 cm culture dish for printing. The difference is that in step (4), the printing pallet is set as a round dish. In step (5), before the Z-axis descends after the printing pallet is transported to the three-dimensional moving device, 6 culture dishes are placed in the 6 grooves of the No. 2 pallet, and the operations of the remaining steps are the same. The result of a single printing pallet is as Figure 13 shown. Figure 14 The bright-field microscopic view of the printed cultured meat is shown, and porcine muscle stem cells growing relying on the printed fibers can be observed.

[0145] Example 7

[0146] Flexible circuit mass production

[0147] Preparation of the microfluidic chip: Select a cylindrical glass capillary with an inner diameter of 750 μm and an outer diameter of 1000 μm, and pull the outlet to an inner diameter of about 400 μm to serve as the inner-phase channel; then select another cylindrical glass capillary with an inner diameter of 1580 μm and an outer diameter of 2000 μm, and pull the outlet to an inner diameter of about 1000 μm to serve as the outer-phase channel. The two glass capillaries are kept coaxial and the outlet end face is perpendicular to the central axis of the capillary. The entire microfluidic channel should maintain symmetry. Fix a 20G dispensing needle at the joint of the channels as the liquid inlet.

[0148] Prepare a mixed solution of 10 wt% polyvinyl alcohol and 1 wt% sodium alginate as the outer-phase solution required for the production of the flexible circuit, and prepare a 4 mg / mL MXene solution as the inner-phase solution required for the flexible circuit.

[0149] Use Solidworks software to establish a printing model. The model is a cuboid with dimensions of 12 * 12 * 0.5 mm. Save the model in the.stl format and export it; import the.stl file into Cura software for slicing. Set the slicing parameters as follows: line spacing 0.42 mm, printing speed 10 mm / s. After slicing, save the generated.gcode file to a USB flash drive, insert it into the shell for standby, and use it for flexible sensor printing.

[0150] Use the equipment in Example 1, and the number of extrusion channels is 3. Operate according to the steps in Example 5, except that in step (1), the inner and outer-phase solutions are the inner and outer-phase solutions of the flexible sensor, the flow rate of the No. 1 liquid inlet pump is 5 mL / h, and the flow rate of the No. 2 liquid inlet pump is 3 mL / h. The printing result of a single printing pallet is as Figure 15 shown. The conductive solution is wrapped inside the cured flexible shell to obtain a flexible circuit.

Claims

1. A large-scale biological 3D printing device, characterized in that: The invention is composed of a liquid inlet system (1), a printing platform (2), a storage system (3), a transmission control system (4), and a printing pallet (5); the transmission control system (4) inputs the printing pallet (5) from the storage box of the storage system (3) to the printing platform (2); the liquid inlet system (1) is connected to the printing platform (2) to provide production raw materials; the printing platform (2) forms and prints products in batches on the printing pallet (5) to obtain finished printing pallets; the transmission control system (4) then outputs the finished printing pallet to the storage rack of the storage system (3); at the same time, the transmission control system (4) can continue to input new printing pallets (5) from the storage box of the storage system (3) to the printing platform (2) to realize a continuous production mode.

2. The large-scale biological 3D printing device according to claim 1, characterized in that: The liquid inlet system (1) comprises m liquid inlet pumps (6), wherein m is an integer ≥ 1, and the liquid inlet pump (6) comprises a motor connecting screw (11), an optical axis (12), an adjusting screw (13), a clamping plate (14), a motor seat (15), a fixing seat (16), a pushing seat (17), a screw nut (18), and a motor (19); the motor connecting screw (11) and the optical axis (12) pass through the two ends of the pushing seat (17) and are connected to the fixing seat (16) and the motor seat (15), and the screw nut (18) inside the pushing seat (17) is connected to the motor connecting screw (11). The engagement can be disengaged, and the clamping plate (14) is arranged on the surface of the pushing seat (17) and the fixing seat (16), and the clamping plate (14) can be locked by means of an adjusting screw (13); the motor (19) is located below the motor seat (15), and the screw nut (18) is located inside the pushing seat (17); the injection device (10) loaded by the liquid inlet pump (6) is fixed in the groove of the fixing seat (16) by means of the clamping plate (14) and the adjusting screw (13), and the motor is connected to the screw (11) to drive the pushing seat (17) to reciprocate along the optical axis (12) to realize the extraction and injection of the injection device (10).

3. The large-scale biological 3D printing device according to claim 2, characterized in that: Each of the m liquid inlet pumps (6) is independently controlled, the number of grooves of the fixing seat (16) is n, and a single liquid inlet pump (6) can simultaneously load 1 to n syringes, wherein n is an integer ≥ 1. Preferably, different liquid inlet pumps can load syringes of different specifications, and m and n can be freely selected as needed.

4. The large-scale biological 3D printing device according to claim 2, characterized in that: The motor (19) and the motor connecting screw (11) are connected in a manner selected from the group consisting of a coupling, gear transmission, synchronous belt transmission, chain transmission, and direct coupling. The motor connecting screw (11) is selected from the group consisting of a trapezoidal screw, a static pressure screw, and a ball screw.

5. The large-scale biological 3D printing device according to claim 1, characterized in that: The printing platform (2) comprises a three-dimensional moving device (21) and a printing nozzle (22); the three-dimensional moving device (21) is connected to and drives the printing nozzle (22) to move, and the printing nozzle (22) is provided with one or more extrusion channels (23) and can extrude printing materials on the printing support plate (5) to form a stack; the extrusion channels (23) are fixed or freely and quickly detachable from the printing nozzle (22), and the number of the extrusion channels can be freely adjusted as needed, and the distance between the extrusion channels can be automatically changed as needed.

6. The large-scale biological 3D printing device according to claim 5, characterized in that: The structure of the three-dimensional moving device (21) is one of a gantry structure, a cantilever structure, a Makerbot structure, an Ultmaker structure, an Hbot structure, a Core XY structure, and a parallel arm structure.

7. The large-scale biological 3D printing device according to claim 5, characterized in that: A single extrusion channel (23) of the print head (22) is equipped with a channel sensor (25), a support plate sensor (26), a fixed slider (27) and an adjustment motor (24), which are used for automatic leveling of each extrusion channel (23) adapted to different printing support plates (5). The channel sensor (25) can detect the bottom position of the extrusion channel (23); the support plate sensor (26) can detect the position of the printing support plate (5) below. When the printing support plate (5) moves from far to near to a set distance from the support plate sensor (26), the support plate sensor is triggered. (26); the extrusion channel (23) is installed in the fixed slider (27); the adjustment motor (24) is located behind the fixed slider (27) and is used to control the up and down movement of the fixed slider (27), thereby driving the up and down movement of the extrusion channel (23); the channel sensor (25) is one or more of a photoelectric sensor, a capacitive sensor, an inductive sensor, a pressure sensor, and a micro switch; the support plate sensor (26) is one or more of a BL-touch, a photoelectric sensor, a capacitive sensor, an inductive sensor, a pressure sensor, and a micro switch.

8. The large-scale biological 3D printing device according to claim 7, characterized in that: The extrusion channel (23) is also equipped with a zeroing sensor (91), a mounting block (92), a horizontal motor (93), and a wire interface (94), which are used to realize the rapid disassembly and installation and pitch change of the extrusion channel (23); the zeroing sensor (91) is located on the left side of the extrusion channel (23) and is used for positioning the extrusion channel (23), and is one of a photoelectric sensor, a capacitive sensor, an inductive sensor, a pressure sensor, and a micro switch; the mounting block (92) is located on the rear side of the extrusion channel (22) and is used for connecting and disconnecting the extrusion channel (22) and its accessories from the print head (22); the horizontal motor (93) is located on the rear side of the extrusion channel and is used to control the extrusion channel (23) to move left and right and change its pitch; the wire interface (94) is located on the top of the extrusion channel (23) and is used to connect various accessories of the extrusion channel (23) to the control circuit.

9. The large-scale biological 3D printing device according to claim 5, characterized in that: The extrusion channel (23) can be connected to an injection device (10) installed on the liquid inlet system (1) through a catheter, or can be externally connected to an air pump, a peristaltic pump, or can be directly integrated with the liquid inlet system (1); the extrusion channel (23) is one or more of a microfluidic chip, a pneumatic extrusion head, a piston extrusion head and a spiral extrusion head, which can be flexibly replaced; the extrusion channel (23) can extrude the printing material to generate a solid type, a "shell core" type, a spiral type, a multi-component type or a hollow type structure.

10. The large-scale biological 3D printing device according to claim 1, characterized in that: The storage system (3) comprises a spare storage box (31), a finished product storage rack (32), a printing pallet (5), and a housing (33); the printing pallet (5) comprises a spare printing pallet (51) to be printed and a finished product printing pallet (52) after printing; the spare storage box (31) stores the spare printing pallet (51) to be printed, and the finished product storage rack (32) stores the finished product printing pallet (52) after printing; the printing pallet (5) is used for the printing platform (2) to undertake printing; and the housing (33) is used to fix the liquid inlet system (1), the printing platform (2), the spare storage box (31), the finished product storage rack (32) and the transmission control system (4).

11. The large-scale biological 3D printing device according to claim 10, characterized in that: The finished product storage rack (32) is provided with one or more layers of brackets (38) for placing finished product printing pallets (52) at intervals, and the spare finished product box is provided with a lifting platform (35) for controlling the contact and separation of the spare printing pallet (51) and the conveyor (42).

12. The large-scale biological 3D printing device according to claim 10, characterized in that: The housing (33) is provided with a plurality of expansion interfaces (39), which can be used to install one or more of a USB flash drive, a limit switch, a photoelectric sensor, a heater, an ultraviolet lamp, a liquid storage tank, a camera, a fan, a mechanical arm, and an external host computer.

13. The large-scale biological 3D printing device according to claim 10, characterized in that: The printing support plate (5) can be directly used for printing by the printing nozzle (22) on its surface, or a plurality of grooves of different shapes can be arranged on its surface according to the spacing of the extrusion channels (23) to place a plurality of collecting containers of different specifications for the printing nozzle (22) to receive printing; the printing support plate (5) can be detachably connected to the three-dimensional moving device (21) by clamping, snapping, plugging, magnetic attraction, mortise and tenon, riveting, threading or bayonet; the material of the printing support plate (5) is one or more of polyvinyl chloride, polypropylene, polymethyl methacrylate, phenolic resin, polyethylene, polyoxymethylene, polyetheretherketone, polyethylene terephthalate, polycarbonate, acrylonitrile-butadiene-styrene copolymer, polylactic acid, glass, ceramics, wood, aluminum and its alloys, iron and its alloys.

14. The large-scale biological 3D printing device according to claim 1, characterized in that: The transmission control system (4) comprises a control panel (41), a conveyor (42), a linear mechanism (43), a controller, and a power supply; the control panel (41) is connected to the controller, the power supply, the liquid inlet system (1), the printing platform (2), the conveyor (42), and the linear mechanism (43) via wires to achieve overall control of the device; the controller and the power supply are installed inside the housing (33); the power supply supplies power to the control panel (41), the controller, the liquid inlet system (1), the printing platform (2), the conveyor (42), and the linear mechanism (43); commands are issued through the control panel (41), the control panel (41) sends command information to the controller, and the controller processes the command information The actions of the liquid inlet system (1), the printing platform (2), the conveyor (42), and the linear mechanism (43) are controlled according to the results; the conveyor (42) is connected to the spare storage box (31), the printing platform (2), and the finished product storage rack (32), and is used to transport the spare printing pallet (51) from the spare storage box (31) to the printing platform (2) and to transport the finished printing pallet (52) from the printing platform (2) to the finished product storage rack (32); the linear mechanism (43) is a support arm that can move up and down, and the finished product printing pallet (52) can be transported from the conveyor (42) to the support arm, and is used to transport the finished product printing pallet (52) and place it on the bracket (38) of the finished product storage rack (32).

15. The large-scale biological 3D printing device according to claim 14, characterized in that: The conveying mode of the conveyor (42) is one of belt conveying, chain conveying, roller conveying, screw conveying, and crank rocker conveying.

16. An application of the large-scale biological 3D printing device according to claim 1 in the large-scale production of cell cultured meat, tissues or organs, food, flexible electronic materials or construction production materials.

17. The use according to claim 16, characterized in that The following steps are involved: (1) placing the required spare printing tray (51) in the spare storage box (31), extracting the production raw material solution with the injection device (10), and fixing the injection device (10) in the liquid inlet system (2); (2) connecting the injection device (10) to the print head (22), starting and calibrating the device; (3) Select the file to be printed, set the printing parameters, and start production; (4) The conveyor (42) transports the spare printing pallet (51) from the spare storage box (31) to the middle position of the three-dimensional moving device (21), the printing nozzle (22) is automatically leveled, and the product generated at the outlet of the extrusion channel (23) is stacked layer by layer on the spare printing pallet (51) according to the path generated by the printing file instruction, and printed and solidified; (5) After the printing of a single spare printing pallet (51) is completed, the conveyor (42) outputs the finished printing pallet (52) to the finished product storage rack (32), and the linear mechanism (43) lifts the finished printing pallet (52) and places it on the bracket (38); (6) Repeat steps (4) and (5) until the number of finished product printing pallets (52) is equal to the set number of printing pallets, remove the finished product printing pallets from the finished product storage rack (32), and the production is completed.

18. The use according to claim 16, characterized in that The process of calibrating the device in step (2) is to lower the linear mechanism (43) to the bottom contact housing (33), lift the lifting platform (35) to make the spare printing tray (51) separate from the conveyor (42), and adjust the motor (24) to move the extrusion channel (23) until the bottom of the extrusion channel (23) is just recognized by the channel sensor (25); the printing file in step (3) is a device storage file, a U disk import file or an external host computer transmission file, and the printing parameters include the number of single tray printing columns, the number of printing trays, the printing spacing, the flow rate of the liquid inlet pump, the syringe specifications, the heating temperature, the ultraviolet lamp parameters, the fan parameters, the robot arm parameters, and the printing speed. or more; step (2) and step (3) can be completed by a control panel or an external host computer; in step (4), the print head (22) can print directly on the print pallet (5), or a collecting container can be placed on the print pallet (5) by a mechanical arm or manually for the print head (22) to print; the automatic leveling process in step (4) is to move the print pallet (5) from bottom to top until all pallet sensors (26) are triggered, and the drop value of each extrusion channel (23) from the position identified by the channel sensor is calculated according to the trigger time of each pallet sensor (26); the curing method is one of chemical cross-linking curing, thermal curing, light curing, and dry curing.

19. The use according to claim 16, characterized in that: By changing the production raw material solution, it can be used for production in different fields, including bio-ink for cell cultured meat, tissue or organ production, edible ink for food production, conductive ink for flexible electronics production, and concrete slurry for building material production.

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