High-precision additive manufacturing equipment and high-throughput additive manufacturing systems

Abstract

The present disclosure generally relates to an additive manufacturing system comprising: a material supply module for melting and pressurizing a printing material; a micro-screw print head comprising: a micro-screw having a threaded stem portion and a conical head portion, the threaded stem portion being volumetrically threaded along its entire length; a sleeve; and a nozzle having a distal end comprising an inner conical surface and an outlet port for ejecting the printing material, the inner conical surface of the nozzle configured to contact the conical head portion of the micro-screw to stop ejection of the printing material at the nozzle when the micro-screw print head is in a closed position; and a drive module comprising: a rotary motor for driving rotational movement of the micro-screw and an actuator for driving vertical movement of the micro-screw.

Description

Technical Field

[0001] This disclosure generally relates to additive manufacturing technologies, and more specifically to high-throughput and high-precision 3D printing technologies.

Background Art

[0002] Additive manufacturing, also known as three-dimensional printing ("3D printing"), is a rapid prototyping technology that involves a process of joining or solidifying materials to create three-dimensional objects. Specifically, materials are added together, usually layer by layer, based on a digital model (such as liquid molecules or powder particles being fused together). A computer system operates the additive manufacturing system to control the flow of materials and the movement of the printing nozzle until the desired shape is formed. Currently, 3D printing technologies include photocuring methods, powder bonding methods, and fused deposition modeling (FDM) methods.

[0003] Existing additive manufacturing systems that use printing screws have several drawbacks. Many of the existing systems do not have an accurate and instantaneous opening and closing mechanism. For example, even when the printing screw stops rotating, a small amount of printing material may still be discharged / leaked. Therefore, it is impossible to accurately control the amount of printing material discharged, especially at the start and end of a printing session.

[0004] Furthermore, the printing screws of many existing systems are relatively large (e.g., with a diameter on the centimeter scale), and it is difficult to accurately control and track the flow of printing materials. Therefore, these printing screws are not suitable for printing small and complex objects. The printing screws of these systems have three sections: a section configured to introduce printing materials, a section configured to pressurize printing materials, and a section configured to measure the volume of the discharged printing materials (i.e., metering). Since multiple sections are designed for multiple applications, it is difficult to reduce the size of the printing screw.

[0005] Furthermore, the printing threads in many existing systems are not designed to properly match the corresponding nozzles, leaving a gap within the nozzle even when it is closed. As a result, after each printing session, residual printing material remains in the gap, which can therefore affect volume tracking for current and future printing sessions.

[0006] Therefore, there is a need for 3D printing systems and methods that can accurately, precisely, and cost-effectively print relatively small, intricate, and complex objects while maintaining high throughput over the long term. A system is also needed that can synchronize the operation of multiple 3D printers to print batches of products. [Overview of the Initiative] [Means for solving the problem]

[0007] An exemplary additive manufacturing system comprises: a material supply module for melting and pressurizing a printing material; a microscrew print head comprising a microscrew having a threaded stem portion and a conical head portion, the threaded stem portion having threads along its entire length for volume measurement; a sleeve; a nozzle having a nozzle whose distal end comprises a conical inner surface and an outlet port for ejecting the printing material, the conical inner surface of the nozzle configured to contact the conical head portion of the microscrew when the microscrew print head is in a closed position to stop the ejection of the printing material from the nozzle; and a drive module comprising a rotary motor for driving the rotational motion of the microscrew and an actuator (e.g., an electric motor) for driving the vertical motion of the microscrew.

[0008] In some embodiments, the system further includes a z-axis positioning sealing ring between the sleeve and the nozzle, the z-axis positioning sealing ring being configured to adjust the vertical position of the nozzle.

[0009] In some embodiments, the microscrew print head further includes a heating sleeve or a temperature sensor.

[0010] In some embodiments, the microscrew print head further comprises an insulating sleeve.

[0011] In some embodiments, the first taper angle of the conical head portion of the microscrew is less than or equal to the second taper angle formed by the conical inner surface of the nozzle.

[0012] In some embodiments, the first taper angle of the conical head portion of the microscrew is 60° or less.

[0013] In some embodiments, the ratio of the second taper angle to the first taper angle is equal to 1:1 to 4:1 or 1:1 to 4:1, equal to 1:1 to 3:1 or 1:1 to 3:1, or equal to 1:1 to 2:1 or 1:1 to 2:1.

[0014] In some embodiments, the conical head portion of the microscrew is frustoconical or truncated cone-shaped.

[0015] In some embodiments, the conical head portion of the microscrew is configured to fit into the conical inner surface of the nozzle via one or more matching patterns.

[0016] In some embodiments, the length of the threaded stem portion of the microscrew is equal to or is between 10 and 80 mm.

[0017] In some embodiments, the diameter of the threaded stem portion of the microscrew is equal to or is between 1 and 10 mm.

[0018] In some embodiments, the diameter is 3 mm, 3.5 mm, 3.6 mm, 4 mm, or 4.5 mm, 4.6 mm.

[0019] In some embodiments, the material supply module includes an extrusion device for melting the printing material and a pressurization device.

[0020] In some embodiments, the extrusion device includes a single piston extrusion mechanism, a single screw extrusion mechanism, a twin screw extrusion mechanism, or any combination thereof.

[0021] In some embodiments, the pressurization device includes a piston extrusion mechanism, a single screw extrusion mechanism, a screw pump mechanism, a gear mechanism, a plunger pump mechanism (e.g., a valveless metering pump mechanism), or any combination thereof.

[0022] In some embodiments, the material supply module includes one or more temperature sensors for detecting the temperature of the melted printing material.

[0023] In some embodiments, the system further includes one or more pressure sensors for detecting the pressure of the melted printing material at the inlet of the flow channel or the micro-screw printing head.

[0024] In some embodiments, the inlet of the micro-screw printing head is aligned based on the uppermost screw segment of the threaded stem portion of the micro-screw.

[0025] In some embodiments, the system further includes an inlet sealing ring at the inlet of the micro-screw printing head.

[0026] In some embodiments, the drive module is configured to independently control the actuator and the rotary motor.

[0027] In some embodiments, the drive module is configured to perform composite control of the actuator and the rotary motor.

[0028] In some embodiments, the actuator includes a pneumatic actuator, a mechanical actuator, an electromagnetic actuator, a hydraulic actuator, or an electric motor.

[0029] In some embodiments, the electric motor is configured to control the speed and acceleration of the vertical movement of the micro screw and / or the travel displacement of the micro screw.

[0030] In some embodiments, the rotary motor is configured to control the rotational speed of the micro screw.

[0031] In some embodiments, the system further includes a cross connector or a cardan shaft used for coupling.

[0032] In some embodiments, the printing material is melted at 50°C to 400°C by a material supply module.

[0033] In some embodiments, the printing material is ejected at 50°C to 400°C by a nozzle.

[0034] In some embodiments, the printing material is a non-filamentous material, and the viscosity when the printing material is ejected by the nozzle is 800 Pa·s or more.

[0035] In some embodiments, the printing material includes a pharmaceutically acceptable material, an inert material, or a combination thereof.

[0036] In some embodiments, the system further includes a printing platform and a controller for moving the printing platform based on a Cartesian coordinate system, a polar coordinate system, or a cylindrical coordinate system.

[0037] An exemplary method of additive manufacturing via a microscrew printhead, comprising: a microscrew having a threaded stem portion and a conical head portion; and a nozzle having a conical inner surface and an outlet port for discharging printing material at its distal end, the method comprising: raising the microscrew to open the outlet port of the nozzle; rotating the microscrew to introduce molten and pressurized printing material into a groove in the threaded stem portion of the microscrew, configured such that the molten and pressurized printing material flows toward the distal end of the nozzle; and lowering the microscrew such that the conical inner surface of the nozzle contacts the conical head portion of the microscrew to close the outlet port and stop the discharging of printing material at the nozzle.

[0038] In some embodiments, the method further includes melting and pressurizing the printing material.

[0039] In some embodiments, the method further includes adjusting the speed and acceleration of the vertical movement of the microscrew and / or the travel displacement of the microscrew via an actuator (e.g., an electric motor).

[0040] In some embodiments, the method further includes controlling the volume of printing material being extruded by adjusting the rotational speed of a microscrew via a rotary motor.

[0041] In some embodiments, actuators (e.g., electric motors) and rotary motors are configured to drive the combined movement of the microscrew.

[0042] In some embodiments, the method further includes lowering the microscrew to close the outlet port while reducing the rotational speed of the microscrew.

[0043] In some embodiments, rotating the microscrew includes rotating the microscrew in a first direction, and the method further includes rotating the microscrew in the opposite direction to the first direction to remove a certain amount of printing material from the distal end of the nozzle before lowering the microscrew to close the exit port.

[0044] In some embodiments, the method further includes coordinating the movement of the printing platform with the amount of printing material discharged by the nozzles.

[0045] In some embodiments, the method further includes heating the printing material according to a ladder scheme, wherein the printing material is heated to a first temperature in a material supply module, the printing material is heated to a second temperature in a flow distribution model, and the printing material is heated to a third temperature in a nozzle.

[0046] In some embodiments, the first temperature is 50°C, the second temperature is 70°C, and the third temperature is 105°C.

[0047] In some embodiments, the method further includes measuring the pressure of the printing material at the inlet of a flow channel or microscrew printhead and controlling the pressure of the printing material via a closed-loop control system.

[0048] In some embodiments, the printing material is a non-filamental material, and its viscosity when extruded by the nozzle is 800 Pa·s or higher.

[0049] In some embodiments, the microscrew is controlled to produce pharmaceutical dosage units.

[0050] An exemplary additive manufacturing system comprises: a material supply module for melting and pressurizing a printing material; a flow distribution module having a flow distribution plate, the flow distribution plate having a plurality of channels for evenly dividing a single flow of molten and pressurized printing material into a plurality of flows; a plurality of microscrew print heads configured to discharge a plurality of flows, each of the plurality of microscrew print heads comprising a microscrew having a threaded stem portion and a conical head portion, the threaded stem portion having threads along its entire length for volume measurement; a sleeve; a nozzle, the distal end of which has a conical inner surface and an outlet port for discharging printing material, the conical inner surface of which is configured to contact the conical head portion of the microscrew when each microscrew print head is in a closed position to stop the discharge of printing material from the nozzle; and a drive module comprising one or more rotary motors for driving the rotational motion of the plurality of microscrews and one or more actuators (e.g., electric motors) for driving the vertical motion of the plurality of microscrews.

[0051] In some embodiments, each microscrew print head further includes a z-axis positioning sealing ring between the sleeve and the nozzle, the z-axis positioning sealing ring being configured to adjust the vertical position of the nozzle.

[0052] In some embodiments, each microscrew print head further comprises a heating sleeve or a temperature sensor.

[0053] In some embodiments, each microscrew print head further comprises an insulating sleeve.

[0054] In some embodiments, for each microscrew print head, the first taper angle of the conical head portion of the microscrew is less than or equal to the second taper angle formed by the conical inner surface of the nozzle.

[0055] In some embodiments, the first taper angle of the conical head portion of the microscrew is 60° or less.

[0056] In some embodiments, the ratio of the second taper angle to the first taper angle is equal to 1:1 to 4:1 or 1:1 to 4:1, equal to 1:1 to 3:1 or 1:1 to 3:1, or equal to 1:1 to 2:1 or 1:1 to 2:1.

[0057] In some embodiments, for each microscrew print head, the conical head portion of the microscrew is frustoconical or truncated cone.

[0058] In some embodiments, for each microscrew print head, the conical head portion of the microscrew is configured to fit onto the conical inner surface of the nozzle via one or more matching patterns.

[0059] In some embodiments, for each microscrew print head, the length of the threaded stem portion of the microscrew is equal to or is between 10 and 80 mm.

[0060] In some embodiments, for each microscrew print head, the diameter of the threaded stem portion of the microscrew is equal to or is between 1 and 10 mm.

[0061] In some embodiments, the material supply module includes an extrusion device for melting the printing material and a pressurizing device.

[0062] In some embodiments, the extrusion device includes a single-piston extrusion mechanism, a single-screw extrusion mechanism, a twin-screw extrusion mechanism, or any combination thereof.

[0063] In some embodiments, the pressurizing device includes a piston extrusion mechanism, a single-screw extrusion mechanism, a screw pump mechanism, a gear mechanism, a plunger pump mechanism (e.g., a valveless measuring pump mechanism), or any combination thereof.

[0064] In some embodiments, the material supply module includes one or more temperature sensors for detecting the temperature of the molten printing material.

[0065] In some embodiments, the system further includes one or more pressure sensors on the flow distribution plate or inlet of the print head for detecting the pressure of the molten printing material.

[0066] In some embodiments, for each microscrew print head, the inlet of the microscrew print head is aligned based on the uppermost threaded segment of the threaded stem portion of the microscrew.

[0067] In some embodiments, one or more rotary motors comprise a plurality of rotary motors, each of which is configured to control the rotational speed of each microscrew of a plurality of microscrew printheads.

[0068] In some embodiments, a single rotary motor is provided, configured to simultaneously control the rotational speed of the microscrews of multiple microscrew printheads.

[0069] In some embodiments, the actuator includes a pneumatic actuator, a mechanical actuator, an electromagnetic actuator, a hydraulic actuator, or an electric motor.

[0070] In some embodiments, one or more actuators comprise a plurality of electric motors, each of which is configured to control the speed and acceleration of the vertical movement of each microscrew and / or the travel displacement of each microscrew.

[0071] In some embodiments, a single electric motor is provided, configured to simultaneously control the vertical speed and acceleration of multiple microscrews, as well as the travel displacement of multiple microscrews, via a push plate mechanism.

[0072] In some embodiments, the push plate mechanism includes a sliding plate, a push plate, and a cam mechanism.

[0073] In some embodiments, the cam mechanism is configured to convert the horizontal movement of the sliding plate into the vertical movement of the push plate.

[0074] In some embodiments, the drive module is configured to independently control one or more actuators and one or more rotary motors.

[0075] In some embodiments, the drive module performs combined control of one or more actuators and one or more rotary motors.

[0076] In some embodiments, at least one of the one or more rotary motors and one or more actuators is a stepping motor.

[0077] In some embodiments, the system further comprises a cross connector or cardan shaft used for coupling.

[0078] In some embodiments, the flow distribution module comprises a base plate, and the flow distribution plate and a plurality of microscrew print heads are arranged within the base plate.

[0079] In some embodiments, the flow distribution plate comprises an upper plate and a lower plate.

[0080] In some embodiments, the base plate and the sleeves for multiple microscrew print heads are integrated.

[0081] In some embodiments, the system further includes a temperature control system outside the flow distribution plate, the temperature control system comprising a heating device and a cooling device.

[0082] In some embodiments, the inlet of the flow distribution plate includes a sealing mechanism.

[0083] In some embodiments, the entrance to the microscrew print head includes a sealing mechanism.

[0084] In some embodiments, the sealing mechanism is a sealing ring.

[0085] In some embodiments, multiple microscrew print heads are arranged in a natural equilibrium layout or a rheological equilibrium layout.

[0086] In some embodiments, the flow distribution plate is configured to divide a single flow into four or eight flows.

[0087] In some embodiments, the flow distribution plate is configured to divide a single flow into 16 or 32 flows via one or more 1:4 or 1:8 subplates.

[0088] In some embodiments, the flow distribution plate is configured to divide a single flow into three, five, or seven flows via a rheological equilibrium layout.

[0089] In some embodiments, the printing material is melted at 50°C to 400°C by a material supply module.

[0090] In some embodiments, the printing material is ejected by a nozzle at a temperature of 50°C to 400°C.

[0091] In some embodiments, the printing material is a non-filamental material, and its viscosity when extruded by the nozzle is 800 Pa·s or higher.

[0092] In some embodiments, the printing material includes a pharmaceutically acceptable material, an inert material, or a combination thereof.

[0093] In some embodiments, the system further comprises a printing platform and a controller for moving the printing platform based on a Cartesian coordinate system, a polar coordinate system, or a cylindrical coordinate system.

[0094] An exemplary method of additive manufacturing via a plurality of microscrew printheads, each of the plurality of microscrew printheads comprising: a microscrew having a threaded stem portion and a conical head portion; and a nozzle having a conical inner surface and an outlet port for discharging printing material at its distal end, the method comprising: distributing a single flow of molten and pressurized printing material through a flow distribution plate into a plurality of flows; directing each of the plurality of flows to the microscrew heads of the plurality of microscrew printheads; at each microscrew printhead, raising the microscrew to open the outlet port of the nozzle; rotating the microscrew to introduce the respective flow into the groove of the threaded stem portion of the microscrew, configured such that the molten and pressurized printing material flows toward the distal end of the nozzle; and lowering the microscrew such that the conical inner surface of the nozzle contacts the conical head portion to close the outlet port and stop the discharging of printing material at the nozzle.

[0095] In some embodiments, the method further includes melting and compressing the printing material.

[0096] In some embodiments, an electric motor is configured to simultaneously control the vertical speed and acceleration of multiple microscrews, as well as the travel displacement of multiple microscrews, via a push plate mechanism.

[0097] In some embodiments, each of the multiple electric motors is configured to control the vertical speed and acceleration of each microscrew, as well as the travel displacement of each microscrew.

[0098] In some embodiments, each of the multiple rotary motors is configured to control the rotational speed of its respective microscrew via a motor adapter shaft.

[0099] In some embodiments, a single rotary motor is configured to simultaneously control the rotational speed of the microscrews of multiple microscrew printheads via one or more gears and belts.

[0100] In some embodiments, the actuator and rotary motor are configured to drive the combined movement of the microscrew.

[0101] In some embodiments, the method further includes lowering the microscrew to close the outlet port while reducing the rotational speed of the microscrew.

[0102] In some embodiments, rotating the microscrew includes rotating the microscrew in a first direction, and the method further includes rotating the microscrew in the opposite direction to the first direction to remove a certain amount of printing material from the distal end of the nozzle before lowering the microscrew to close the exit port.

[0103] In some embodiments, the method further includes coordinating the movement of the printing platform with the amount of printing material discharged by the nozzles.

[0104] In some embodiments, the method further includes heating a printing material according to a ladder scheme, wherein the printing material is heated to a first temperature in a material supply module, the printing material is heated to a second temperature in a flow distribution model, and the printing material is heated to a third temperature at each nozzle.

[0105] In some embodiments, the first temperature is 50°C, the second temperature is 70°C, and the third temperature is 105°C.

[0106] In some embodiments, the method further includes measuring the pressure of the printing material at the inlet or flow distribution plate of a microscrew print head and controlling the pressure of the printing material via a closed-loop control system.

[0107] In some embodiments, the printing material is a non-filamental material, and its viscosity when extruded by the nozzle is 800 Pa·s or higher.

[0108] In some embodiments, multiple microscrew printing heads are configured to manufacture pharmaceutical dosage units.

[0109] An exemplary additive manufacturing system comprises: a first printing station comprising: a first material supply module for melting and pressurizing a first printing material; a first flow distribution module configured to evenly divide a single flow of the molten and pressurized first printing material into a first plurality of flows; and a first printing module comprising: a second printing station comprising: a second material supply module for melting and pressurizing a second printing material; a second flow distribution module configured to evenly divide a single flow of the molten and pressurized second printing material into a second plurality of flows; and a second printing module comprising: a second printing module comprising: a second microscrew print head configured to discharge a second plurality of flows.

[0110] In some embodiments, the first and second printing stations are configured to print the same batch of products.

[0111] In some embodiments, each of the first and second printing modules is configured to be extendable to accommodate a different number of print heads.

[0112] In some embodiments, each of the first and second printing stations is configured to be extendable to accommodate different types of printing modules.

[0113] In some embodiments, the system further includes a set of droplet-ejection printheads, a set of injection printheads, a set of inkjet printheads, or any combination thereof.

[0114] In some embodiments, multiple pharmaceutical tablets are prepared using one or more microscrew printing heads of an additive manufacturing system by any one of the methods described herein. In some embodiments, all pharmaceutical tablets weighing 300 mg or less have a relative deviation of ±7.5% or less. In some embodiments, all pharmaceutical tablets weighing 300 mg or more have a relative deviation of ±5% or less. The present invention provides, for example, the following: (Item 1) An additive manufacturing system, A material supply module for melting and pressurizing printing materials, A microscrew print head, A microscrew comprising a threaded stem portion and a conical head portion, wherein the threaded stem portion has threads along its entire length for volume measurement, Sleeves and A nozzle, wherein the distal end of the nozzle is The inner surface of the cone, and It is equipped with an outlet port for dispensing the aforementioned printing material, A microscrew print head comprising: a nozzle, wherein the conical inner surface of the nozzle is configured to contact the conical head portion of the microscrew when the microscrew print head is in the closed position, thereby stopping the ejection of the printing material from the nozzle; It is a drive module, A rotary motor for driving the rotational motion of the aforementioned microscrew, A system comprising a drive module, which includes an actuator for driving the vertical motion of the microscrew. (Item 2) The system according to item 1, further comprising a z-axis positioning sealing ring between the sleeve and the nozzle, wherein the z-axis positioning sealing ring is configured to adjust the vertical position of the nozzle. (Item 3) The system according to item 1 or 2, wherein the microscrew print head further comprises a heating sleeve or a temperature sensor. (Item 4) The system according to any one of items 1 to 3, wherein the microscrew print head further comprises an insulating sleeve. (Item 5) The system according to any one of items 1 to 4, wherein the first taper angle of the conical head portion of the microscrew is less than or equal to the second taper angle formed by the conical inner surface of the nozzle. (Item 6) The system according to item 5, wherein the first taper angle of the conical head portion of the microscrew is 60° or less. (Item 7) The system according to item 5, wherein the ratio of the second taper angle to the first taper angle is equal to 1:1 to 4:1 or 1:1 to 4:1, equal to 1:1 to 3:1 or 1:1 to 3:1, or equal to 1:1 to 2:1 or 1:1 to 2:1. (Item 8) The system according to any one of items 1 to 7, wherein the conical head portion of the microscrew is frustoconical or truncated cone. (Item 9) The system according to any one of items 1 to 8, wherein the conical head portion of the microscrew is configured to fit into the conical inner surface of the nozzle via one or more matching patterns. (Item 10) The system according to any one of items 1 to 9, wherein the length of the threaded stem portion of the microscrew is equal to or is between 10 and 80 mm. (Item 11) The system according to any one of items 1 to 10, wherein the diameter of the threaded stem portion of the microscrew is equal to or is between 1 and 10 mm. (Item 12) The system according to any one of items 1 to 11, wherein the material supply module comprises an extrusion device for melting the printing material and a pressurizing device. (Item 13) The system according to item 12, wherein the extrusion device comprises a single-piston extrusion mechanism, a single-screw extrusion mechanism, a twin-screw extrusion mechanism, a conical twin-screw extrusion mechanism, or any combination thereof. (Item 14) The system according to item 12, wherein the pressurizing device includes a piston extrusion mechanism, a single-screw extrusion mechanism, a screw pump mechanism, a gear mechanism, a plunger pump mechanism (e.g., a valveless measuring pump mechanism), or any combination thereof. (Item 15) The system according to any one of items 1 to 14, wherein the material supply module comprises one or more temperature sensors for detecting the temperature of the molten printing material. (Item 16) The system according to any one of items 1 to 15, further comprising one or more pressure sensors in the flow channel or at the inlet of the microscrew print head for detecting the pressure of the molten printing material. (Item 17) The system according to any one of items 1 to 16, wherein the entrance of the microscrew print head is aligned based on the uppermost threaded segment of the threaded stem portion of the microscrew. (Item 18) The system according to item 17, further comprising an inlet sealing ring at the inlet of the microscrew print head. (Item 19) The system according to any one of items 1 to 18, wherein the drive module is configured to independently control the actuator and the rotary motor. (Item 20) The system according to any one of items 1 to 19, wherein the drive module is configured to perform combined control of the actuator and the rotary motor. (Item 21) The system according to any one of items 1 to 20, wherein the actuator is a pneumatic actuator, a mechanical actuator, an electromagnetic actuator, a hydraulic actuator, or an electric motor. (Item 22) The system according to item 21, wherein the electric motor is configured to control the speed and acceleration of the vertical movement of the microscrew and / or the travel displacement of the microscrew. (Item 23) The system according to any one of items 1 to 22, wherein the rotary motor is configured to control the rotational speed of the microscrew. (Item 24) The system according to any one of items 1 to 23, further comprising a cross connector or cardan shaft used for coupling. (Item 25) The system according to any one of items 1 to 24, wherein the printing material is melted at 50°C to 400°C by the material supply module. (Item 26) The system according to any one of items 1 to 25, wherein the printing material is ejected by the nozzle at a temperature of 50°C to 400°C. (Item 27) The system according to any one of items 1 to 26, wherein the printing material is a non-filamentary material and the viscosity of the printing material when extruded by the nozzle is 800 Pa·s or more. (Item 28) The system according to any one of items 1 to 27, wherein the printing material includes a pharmaceutically acceptable material, an inert material, or a combination thereof. (Item 29) The system according to any one of items 1 to 28, further comprising a printing platform and a controller for moving the printing platform based on a Cartesian coordinate system, a polar coordinate system, or a cylindrical coordinate system. (Item 30) Additive manufacturing method via microscrew print head, The aforementioned microscrew print head A microscrew having a threaded stem and a conical head, A nozzle, wherein the distal end of the nozzle is The inner surface of the cone, and A nozzle comprising an outlet port for dispensing the aforementioned printing material, The method described above is Raising the microscrew opens the outlet port of the nozzle, The process involves rotating the microscrew to introduce molten and pressurized printing material into the groove of the threaded stem portion of the microscrew, wherein the molten and pressurized printing material is configured to flow toward the distal end of the nozzle. A method comprising lowering the microscrew such that the conical inner surface of the nozzle contacts the conical head portion of the microscrew to close the outlet port and stop the ejection of the printing material from the nozzle. (Item 31) The method according to item 30, further comprising melting and pressurizing the printing material. (Item 32) The method according to item 30 or 31, further comprising adjusting the speed and acceleration of the vertical movement of the microscrew and / or the travel displacement of the microscrew via an electric motor. (Item 33) The method according to any one of items 30 to 32, further comprising controlling the volume of the printing material to be extruded by adjusting the rotational speed of the microscrew via a rotary motor. (Item 34) The method according to any one of items 30 to 33, wherein an electric motor and a rotary motor are configured to drive the combined movement of the microscrew. (Item 35) The method according to any one of items 30 to 34, further comprising lowering the microscrew while reducing the rotational speed of the microscrew to close the outlet port. (Item 36) Rotating the microscrew includes rotating the microscrew in a first direction, and the method is The method according to any one of items 30 to 35, comprising rotating the microscrew in the opposite direction to the first direction to remove a certain amount of the printing material from the distal end of the nozzle before lowering the microscrew to close the outlet port. (Item 37) The method according to any one of items 30 to 36, further comprising moving the printing platform and adjusting the amount of printing material discharged by the nozzle. (Item 38) The process further includes heating the printing material according to a ladder scheme, The printing material is heated to a first temperature in the material supply module. The printing material is heated to a second temperature in the flow rate distribution model. The method according to any one of items 30 to 37, wherein the printing material is heated to a third temperature in the nozzle. (Item 39) The method according to any one of items 30 to 38, wherein the first temperature is 50°C, the second temperature is 70°C, and the third temperature is 105°C. (Item 40) The method according to any one of items 30 to 39, further comprising measuring the pressure of the printing material at the inlet of the flow channel or the microscrew print head, and controlling the pressure of the printing material via a closed-loop control system. (Item 41) The method according to any one of items 30 to 40, wherein the printing material is a non-filamentary material and the viscosity of the printing material when extruded by the nozzle is 800 Pa·s or more. (Item 42) The method according to any one of items 30 to 41, wherein the microscrew is controlled to produce a pharmaceutical dosage unit. (Item 43) An additive manufacturing system, A material supply module for melting and pressurizing printing materials, A flow distribution module comprising a flow distribution plate, wherein the flow distribution plate comprises a plurality of channels for evenly dividing a single flow of the molten and pressurized printing material into a plurality of flows, Multiple microscrew print heads configured to discharge multiple flows, each of the multiple microscrew print heads is A microscrew comprising a threaded stem portion and a conical head portion, wherein the threaded stem portion has threads along its entire length for volume measurement, Sleeves and A microscrew print head comprising: a nozzle, the distal end of which includes a conical inner surface and an outlet port for ejecting the printing material, and the conical inner surface of the nozzle is configured to contact the conical head portion of the microscrew when each of the microscrew print heads is in the closed position to stop the ejection of the printing material from the nozzle; It is a drive module, One or more rotary motors for driving the rotational motion of the plurality of microscrews, A system comprising a drive module, which includes one or more actuators for driving the vertical movement of the plurality of microscrews. (Item 44) The system according to item 43, wherein each microscrew print head further includes a z-axis positioning sealing ring between the sleeve and the nozzle, the z-axis positioning sealing ring being configured to adjust the vertical position of the nozzle. (Item 45) The system according to item 43 or 44, wherein each microscrew print head further comprises a heating sleeve or a temperature sensor. (Item 46) Each microscrew print head further comprises an insulating sleeve, as described in any one of items 43-45. (Item 47) The system according to any one of items 43 to 46, wherein for each microscrew print head, the first taper angle of the conical head portion of the microscrew is less than or equal to the second taper angle formed by the conical inner surface of the nozzle. (Item 48) The system according to item 47, wherein the first taper angle of the conical head portion of the microscrew is 60° or less. (Item 49) The system according to item 47, wherein the ratio of the second taper angle to the first taper angle is equal to 1:1 to 4:1 or 1:1 to 4:1, equal to 1:1 to 3:1 or 1:1 to 3:1, or equal to 1:1 to 2:1 or 1:1 to 2:1. (Item 50) The system according to any one of items 43 to 49, wherein for each microscrew print head, the conical head portion of the microscrew is frustoconical or truncated cone. (Item 51) The system according to any one of items 43 to 50, wherein for each microscrew print head, the conical head portion of the microscrew is configured to fit into the conical inner surface of the nozzle via one or more matching patterns. (Item 52) The system according to any one of items 43 to 51, wherein for each microscrew print head, the length of the threaded stem portion of the microscrew is equal to or is between 10 and 80 mm. (Item 53) The system according to any one of items 43 to 52, wherein for each microscrew print head, the diameter of the threaded stem portion of the microscrew is equal to or is between 1 and 10 mm. (Item 54) The system according to any one of items 43 to 53, wherein the material supply module comprises an extrusion device for melting the printing material and a pressurizing device. (Item 55) The system according to item 54, wherein the extrusion device comprises a single-piston extrusion mechanism, a single-screw extrusion mechanism, a twin-screw extrusion mechanism, a conical twin-screw extrusion mechanism, or any combination thereof. (Item 56) The system according to item 54, wherein the pressurizing device includes a piston extrusion mechanism, a single-screw extrusion mechanism, a screw pump mechanism, a gear mechanism, a plunger pump mechanism (e.g., a valveless measuring pump mechanism), or any combination thereof. (Item 57) The system according to any one of items 43 to 56, wherein the material supply module comprises one or more temperature sensors for detecting the temperature of the molten printing material. (Item 58) The system according to any one of items 43 to 57, further comprising one or more pressure sensors at the flow distribution plate or the inlet of the print head for detecting the pressure of the molten printing material. (Item 59) The system according to any one of items 43 to 58, wherein for each microscrew print head, the inlet of the microscrew print head is aligned based on the uppermost threaded segment of the threaded stem portion of the microscrew. (Item 60) The system according to any one of items 43 to 59, wherein the one or more rotary motors comprises a plurality of rotary motors, each of which is configured to control the rotational speed of each of the plurality of microscrews of the plurality of microscrew print heads. (Item 61) The system according to any one of items 43 to 60, wherein the one or more rotary motors comprises a single rotary motor configured to simultaneously control the rotational speed of the microscrews of the plurality of microscrew printheads. (Item 62) The system according to any one of items 43 to 61, wherein the actuator includes a pneumatic actuator, a mechanical actuator, an electromagnetic actuator, a hydraulic actuator, or an electric motor. (Item 63) The system according to any one of items 43 to 62, wherein the one or more actuators comprises a plurality of electric motors, each of which is configured to control the speed and acceleration of the vertical movement of each microscrew and / or the travel displacement of each microscrew. (Item 64) The system according to item 63, comprising one or more electric motors configured to simultaneously control the vertical speed and acceleration of the plurality of microscrews and the travel displacement of the plurality of microscrews via a push plate mechanism. (Item 65) The system according to item 64, wherein the push plate mechanism includes a sliding plate, a push plate, and a cam mechanism. (Item 66) The system according to item 65, wherein the cam mechanism is configured to convert the horizontal movement of the sliding plate into the vertical movement of the push plate. (Item 67) The system according to any one of items 43 to 66, wherein the drive module is configured to independently control one or more actuators and one or more rotary motors. (Item 68) The drive module is a system according to any one of items 43 to 67, which performs combined control of the one or more actuators and the one or more rotary motors. (Item 69) The system according to any one of items 43 to 68, wherein at least one of the one or more rotary motors and the one or more actuators is a stepping motor. (Item 70) The system according to any one of items 43 to 69, further comprising a cross connector or cardan shaft used for coupling. (Item 71) The system according to any one of items 43 to 70, wherein the flow distribution module comprises a base plate, and the flow distribution plate and the plurality of microscrew print heads are arranged within the base plate. (Item 72) The system according to item 71, wherein the flow rate distribution plate comprises an upper plate and a lower plate. (Item 73) The system according to item 71, wherein the base plate and the sleeves of the plurality of microscrew print heads are integrated. (Item 74) The system according to any one of items 43 to 73, further comprising a temperature control system outside the flow distribution plate, wherein the temperature control system comprises a heating device and a cooling device. (Item 75) The system according to any one of items 43 to 74, wherein the inlet of the flow distribution plate is equipped with a sealing mechanism. (Item 76) A system according to any one of items 43 to 75, wherein the inlet of the microscrew printhead is equipped with a sealing mechanism. (Item 77) The system according to item 76, wherein the sealing mechanism is a sealing ring. (Item 78) The system according to any one of items 43 to 77, wherein the plurality of microscrew print heads are arranged in a natural equilibrium layout or a rheological equilibrium layout. (Item 79) The system according to any one of items 43 to 78, wherein the flow distribution plate is configured to divide the single flow into four or eight flows. (Item 80) The system according to item 79, wherein the flow distribution plate is configured to divide the single flow into 16 or 32 flows via one or more 1:4 or 1:8 subplates. (Item 81) The system according to any one of items 43 to 80, wherein the flow distribution plate is configured to divide the single flow into three, five, or seven flows via a rheological equilibrium layout. (Item 82) The system according to any one of items 43 to 81, wherein the printing material is melted at 50°C to 400°C by the material supply module. (Item 83) The system according to any one of items 43 to 82, wherein the printing material is ejected by the nozzle at a temperature of 50°C to 400°C. (Item 84) The system according to any one of items 43 to 83, wherein the printing material is a non-filamentary material and the viscosity of the printing material when extruded by the nozzle is 800 Pa·s or more. (Item 85) The system according to any one of items 43 to 84, wherein the printing material includes a pharmaceutically acceptable material, an inert material, or a combination thereof. (Item 86) The system according to any one of items 43 to 85, further comprising a printing platform and a controller for moving the printing platform based on a Cartesian coordinate system, a polar coordinate system, or a cylindrical coordinate system. (Item 87) Additive manufacturing method via multiple microscrew print heads, wherein each of the multiple microscrew print heads A microscrew having a threaded stem and a conical head, A nozzle, wherein the distal end of the nozzle is provided with a conical inner surface and an outlet port for discharging the printing material, The method described above is Distributing a single flow of molten and pressurized printing material into multiple flows via a flow distribution plate, To cause each of the aforementioned multiple flows to reach the microscrew heads of the aforementioned multiple microscrew print heads, In each microscrew print head, Raising the microscrew opens the outlet port of the nozzle, Rotating the microscrew to introduce the respective flows into the grooves of the threaded stem portion of the microscrew, such that the molten and pressurized printing material flows toward the distal end of the nozzle, and introducing the flow. A method comprising lowering the microscrew such that the conical inner surface of the nozzle contacts the conical head portion of the microscrew to close the outlet port and stop the ejection of the printing material from the nozzle. (Item 88) The method according to item 87, further comprising melting and pressurizing the printing material. (Item 89) The method according to item 87 or 88, wherein an electric motor is configured to simultaneously control the vertical speed and acceleration of the plurality of microscrews and the travel displacement of the plurality of microscrews via a push plate mechanism. (Item 90) The method according to any one of items 87 to 89, wherein each of the multiple electric motors is configured to control the vertical speed and acceleration of each microscrew, as well as the travel displacement of each microscrew. (Item 91) The method according to any one of items 87 to 90, wherein each of the multiple rotary motors is configured to control the rotational speed of its respective microscrew via a motor adapter shaft. (Item 92) The system according to any one of items 87 to 91, wherein a single rotary motor is configured to simultaneously control the rotational speed of the microscrews of the plurality of microscrew printheads via one or more gears and belts. (Item 93) The method according to any one of items 87 to 92, wherein the actuator and the rotary motor are configured to drive the combined movement of the microscrew. (Item 94) The method according to any one of items 87 to 93, further comprising lowering the microscrew while reducing the rotational speed of the microscrew to close the outlet port. (Item 95) Rotating the microscrew includes rotating the microscrew in a first direction, and the method is The method according to any one of items 87 to 94, comprising rotating the microscrew in the opposite direction to the first direction to remove a certain amount of the printing material from the distal end of the nozzle before lowering the microscrew to close the outlet port. (Item 96) The method according to any one of items 87 to 95, further comprising moving the printing platform and adjusting the amount of printing material discharged by the nozzle. (Item 97) The process further includes heating the printing material according to a ladder scheme, The printing material is heated to a first temperature in the material supply module. The printing material is heated to a second temperature in the flow rate distribution model. The method according to any one of items 87 to 96, wherein the printing material is heated to a third temperature in each nozzle. (Item 98) The method according to item 97, wherein the first temperature is 50°C, the second temperature is 70°C, and the third temperature is 105°C. (Item 99) The method according to any one of items 87 to 98, further comprising measuring the pressure of the printing material at the inlet of a microscrew print head or in the flow distribution plate, and controlling the pressure of the printing material via a closed-loop control system. (Item 100) The method according to any one of items 87 to 99, wherein the printing material is a non-filamentary material and the viscosity of the printing material when extruded by the nozzle is 800 Pa·s or more. (Item 101) The method according to any one of items 87 to 100, wherein the plurality of microscrew printing heads are configured to manufacture pharmaceutical dosage units. (Item 102) An additive manufacturing system, The first printing station, A first material supply module for melting and pressurizing the first printing material, A first flow distribution module that evenly divides a single flow of the molten and pressurized first printing material into a first plurality of flows, A first printing station comprising: a first printing module comprising a set of needle valve print heads configured to discharge the first plurality of flows; The second printing station, A second material supply module for melting and pressurizing a second printing material, A second flow distribution module that evenly divides the single flow of the molten and pressurized second printing material into a second plurality of flows, A system comprising: a second printing module having a set of microscrew print heads configured to discharge the second plurality of flows; and a second printing station having a second printing module. (Item 103) The system according to item 102, wherein the first printing station and the second station are configured to print the same batch of products. (Item 104) The system according to item 102 or 103, wherein each of the first and second printing modules is configured to be extendable to accommodate a different number of print heads. (Item 105) The system according to any one of items 102 to 104, wherein each of the first and second printing stations is configured to be extendable to accommodate different types of printing modules. (Item 106) A system as described in any one of items 102 to 105, further including a set of droplet-ejection printheads, a set of injection printheads, a set of inkjet printheads, or any combination thereof. (Item 107) Multiple pharmaceutical tablets prepared using one or more microscrew printing heads of an additive manufacturing system by any one of the methods 30 to 42. (Item 108) The multiple pharmaceutical tablets described in item 107, wherein all pharmaceutical tablets weighing less than 300 mg have a relative deviation of ±7.5% or less. (Item 109) The plurality of pharmaceutical tablets described in item 107, wherein all of the pharmaceutical tablets weighing 300 mg or more have a relative deviation of ±5% or less.

Brief Description of the Drawings

[0115] For a better understanding of the various described embodiments, reference should be made to the following description of the embodiments in conjunction with the following drawings in which like reference numerals refer to corresponding parts throughout the drawings.

[0116] [Figure 1A] A schematic diagram of an exemplary additive manufacturing system according to some embodiments of the present disclosure is shown. [Figure 1B] Schematic diagrams of two exemplary sets of printheads according to some embodiments are shown. [Figure 1C] ​​​​​​​​​​​​​​​​​​Cross-sectional views of four print heads according to several embodiments are shown. [Figure 3A] The following are illustrative cross-sectional views of two microscrew print heads A and B according to several embodiments. [Figure 3B] Cross-sectional views of exemplary microscrew print heads according to several embodiments are shown. [Figure 3C] A cross-sectional view of another exemplary microscrew printhead according to several embodiments is shown. [Figure 3D] Cross-sectional views of exemplary microscrew print heads according to several embodiments are shown. [Figure 4] This document describes exemplary methods for 3D printing according to several embodiments. [Figure 5A] The following are exemplary layouts of a standardized multi-station printing system for pharmaceutical units, according to several embodiments. [Figure 5B] A partial side view of an exemplary multi-station system 800 according to several embodiments is shown. [Figure 6] This document illustrates exemplary electronic devices according to several embodiments. [Figure 7A] The following shows exemplary layouts of 32 print heads according to several embodiments. [Figure 7B] The following shows exemplary layouts of 32 print heads according to several embodiments. [Figure 7C] The following shows exemplary layouts of 32 print heads according to several embodiments. [Figure 8A] Several embodiments of an exemplary push plate mechanism are shown. [Figure 8B] Several embodiments of an exemplary push plate mechanism are shown. [Figure 8C] Several embodiments of an exemplary push plate mechanism are shown. [Figure 9] Schematic diagrams of exemplary additive manufacturing systems according to several embodiments are shown. [Figure 10]Illustrates an exemplary output of an exemplary additive manufacturing system according to some embodiments. [Figure 11] Illustrates an exemplary output of an exemplary additive manufacturing system according to some embodiments. [Figure 12A] Illustrates an exemplary additive manufacturing system (e.g., a 3D printing system) according to some embodiments. [Figure 12B] Shows a cross-sectional view of an exemplary additive manufacturing system (e.g., a 3D printing system) according to some embodiments. [Figure 13A] Illustrates an exemplary push plate mechanism according to some embodiments. [Figure 13B] Presents a cross-sectional view of a push plate mechanism according to some embodiments. [Figure 13C] Illustrates an exemplary push plate mechanism according to some embodiments. [Figure 13D] Illustrates an exemplary push plate mechanism according to some embodiments. [Figure 14A] Shows a cross-sectional view of an exemplary micro screw printing head according to some embodiments. [Figure 14B] Illustrates a schematic view of an exemplary additive manufacturing system (e.g., a 3D printing system) according to some embodiments.

MODE FOR CARRYING OUT THE INVENTION

[0117] This specification describes apparatuses, devices, systems, methods, and non-transitory storage media for accurately, precisely, and cost-effectively additive manufacturing (e.g., 3D printing) an object while maintaining a high throughput over a long period. Embodiments of the present disclosure are suitable for printing relatively small, compact, and / or complex objects such as pharmaceutical dosage units (e.g., tablets, capsules, printlets), medical devices, and implant stents.

[0118] In some embodiments, the exemplary printing system includes one or more microscrew printheads. Each microscrew printhead allows for precise control of the printing material (e.g., pressurized and molten printing material) throughout the entire printing process (e.g., from when the material is introduced until when it is ejected). An exemplary microscrew printhead may comprise a microscrew including a stem portion and a conical head portion, the stem portion having threads along its entire length for volume measurement. The microscrew printhead may further comprise a nozzle, the distal end of which comprises a conical inner surface and an outlet port for ejecting the printing material. During printing, the printing material can reach the nozzle through a groove formed by the threads of the stem portion. When the microscrew printhead is in the closed position, the conical inner surface of the nozzle may be configured to contact the conical head portion of the microscrew to stop the ejection of the printing material at the nozzle. In some embodiments, when the microscrew printhead is in the closed position, the conical head portion of the microscrew has little to no space within the nozzle, and therefore the amount of residue in the nozzle is small.

[0119] In some embodiments, the printing system further comprises one or more rotary motors (e.g., brushless DC motors, stepping motors, servo motors) for driving the rotational motion of a microscrew and one or more actuators (e.g., stepping motors, servo motors) for driving the vertical motion of the microscrew. The actuators can open and close the nozzle and control the speed, acceleration, and travel displacement of the microscrew (thereby allowing the nozzle to be fully open, fully closed, or partially open by any amount), while the rotary motors can control the speed / amount of printing material being ejected. In some embodiments, the rotary motors and actuators can be controlled so that the microscrew rotates and moves vertically simultaneously, rotates only, or moves vertically only.

[0120] According to some embodiments, the printing system utilizes a flow distribution module to divide a single flow of printing material into multiple flows. The multiple flows are precisely controlled and ejected by multiple nozzles to 3D print batches of product (e.g., pharmaceutical dosage units), thus achieving consistency between units in a single batch and between units across multiple batches while maintaining high throughput.

[0121] Furthermore, the printing system includes an environment (e.g., a closed environment such as a constant-temperature oven, an open environment such as a printing platform) for additive manufacturing (e.g., 3D printing) of pharmaceutical dosage units. Multiple closed-loop control systems are used to control temperature, pressure, flow rate, weight, volume, and other relevant parameters within the environment at multiple stages of the manufacturing process. In particular, control systems and methods are implemented for precisely adjusting the nozzle opening to ensure consistency between nozzle outputs. In some embodiments, the inconsistency of unit weight (i.e., inconsistency between the weights of units within the same batch) is less than 10% (e.g., 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 9.5%, 10%). In some embodiments, the inconsistency of batch weight (i.e., inconsistency between the weights of batches) is less than 10% (e.g., 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 9.5%, 10%).

[0122] Based on different types of printing materials and required compositions, the system's control parameters can be adjusted. In this way, a variety of high-quality products can be manufactured using the printing system.

[0123] In some embodiments, the material is non-filamental (e.g., powder, pellet, or liquid). In some embodiments, the viscosity of the material when it is extruded from the system is 0.01 to 10000 Pa·s. For example, the viscosity of the material when it is extruded from the device is about 100 Pa·s or more. In some embodiments, the viscosity of the material when it is extruded from the device is about 400 Pa·s or more. In some embodiments, the viscosity of the material when it is extruded from the device is about 800 Pa·s or more. In some embodiments, the material melts at about 50°C to about 400°C. In some embodiments, the material is extruded from the nozzle at a temperature of about 50°C to about 400°C. In some embodiments, the material is extruded from the nozzle at a temperature of about 90°C to about 300°C.

[0124] In some embodiments, the printing system comprises multiple printing stations. Each printing station can be used to print a portion of a product batch (e.g., shell, lower half, top half, upper half). In some embodiments, multiple printing stations can be operated in parallel, thereby allowing multiple batches of a product to be printed simultaneously. In some embodiments, different printing stations may include different types of print heads (e.g., needle valve print heads, microscrew print heads). The type of print head can be selected based on the type of printing material being ejected. In some embodiments, the multi-station system is easy to clean and maintain, and therefore conforms to the requirements of standardized production of products.

[0125] The following descriptions are provided to enable those skilled in the art to create and use various embodiments. Descriptions of specific devices, techniques, and applications are provided as examples only. Various modifications to the examples described herein will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other examples and applications without departing from the spirit and scope of the various embodiments. Accordingly, the various embodiments are not intended to be limited to the examples described and shown herein, but should be given a scope consistent with the claims.

[0126] The following description includes exemplary methods, parameters, etc. However, it should be understood that such descriptions are provided as illustrative embodiments and not as limitations on the scope of this disclosure.

[0127] In the following description, terms such as "first," "second," etc., are used to describe various elements, but these elements should not be limited by these terms. These terms are used solely to distinguish one element from another. For example, without departing from the scope of the various embodiments described, the first graphic representation may be called the second graphic representation, and similarly, the second graphic representation may be called the first graphic representation. Both the first and second graphic representations are graphic representations, but they are not the same graphic representation.

[0128] The terms used in the description of the various embodiments described herein are intended solely to describe a particular embodiment and are not intended to limit it. As used in the description of the various embodiments described and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural form unless the context clearly indicates otherwise. The terms “and / or” as used herein will be understood to refer to and encompass any and all possible combinations of one or more of the listed items relating. Where used herein, the terms “includes,” “including,” “comprises,” and / or “comprising” specify the presence of the described features, integers, steps, operations, elements, and / or components, but not to exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0129] The term "if" can be interpreted, depending on the context, optionally to mean "when," "upon," "in response to a determination," or "in response to detection." Similarly, the expressions "if determined" or "[the described condition or event] is detected" can be interpreted, depending on the context, optionally to mean "when determined," "in response to a determination," "[the described condition or event] is detected," or "[in response to detection of the described condition or event]."

[0130] Figure 1A shows a schematic diagram of an exemplary additive manufacturing system (e.g., a 3D printing system) 100 according to some embodiments of the present disclosure. The system 100 includes a material supply module 102 for transporting (e.g., continuously transporting) a set of printing material to 32 print heads. In some embodiments, some or all of the 32 print heads are microscrew print heads, which are described in detail herein.

[0131] The material supply module 102 is configured to pre-process a set of printing materials before conveying them through the supply channel 104. In some embodiments, the pre-processing includes melting and pressurizing the printing materials based on predetermined settings (e.g., setting a target temperature range, setting a target pressure range). The pre-processed materials are then conveyed through the supply channel 104. In some embodiments, a continuous flow of printing materials is supplied through the supply channel 104. In some embodiments, the material supply module 102 can continuously pre-process printing materials. For example, printing materials can be continuously introduced into the material supply module (e.g., at a constant or substantially constant rate) and pre-processed while the system is operating. In some embodiments, the material supply module includes a buffer mechanism (e.g., a buffer piston) that can hold the melted and pressurized printing materials when the print head is not ejecting any printing materials (e.g., when changing print stations below the print head), as described below.

[0132] In some embodiments, the material supply module 102 comprises one or more heaters (e.g., heating coils or heating jackets) configured to melt the printing material. In some embodiments, the material supply module comprises one or more temperature sensors configured to detect the temperature of the molten printing material within the material supply module 102. In some embodiments, one or more temperature sensors are connected to a computer system that operates one or more heaters in response to the temperatures reported by the one or more temperature sensors.

[0133] In some embodiments, one or more heaters in the system heat the material in the system to a temperature above the melting point of the material. In some embodiments, one or more heaters heat the material to a temperature of about 60°C or higher, such as about 70°C or higher, 80°C or higher, 100°C or higher, 120°C or higher, 150°C or higher, 200°C or higher, or 250°C or higher. In some embodiments, one or more heaters heat the material to a temperature of about 300°C or lower, such as about 260°C or lower, 200°C or lower, 150°C or lower, 100°C or lower, or 80°C or lower. In some embodiments, one or more heaters heat the material to different temperatures at different locations in the device. For example, in some embodiments, the material is heated to a first temperature in the barrel, to a second temperature in the feeding channel, and to a third temperature in the nozzle, which may be the same temperature or different temperatures, respectively. In some embodiments, the temperature of the material in the nozzle is, for example, 0 to 10°C or 0 to 20°C higher than the temperature of the channels in the feed channel and flow distribution plate. For example, the material may be heated to 140°C in the barrel and feed channel, but to 160°C in the nozzle. A feedback control system enables highly accurate temperature control. In some embodiments, the temperature is controlled to be within 0.1°C, 0.2°C, 0.5°C, 1°C, or 10°C of the target temperature.

[0134] The temperature sensors described herein may include thermocouple sensors (e.g., type J, type K) or resistance thermometers. In some embodiments, the temperature sensor is configured to measure temperatures below 200°C. The pressure sensors described herein include piezoresistive transducers or strain gauge sensors. In some embodiments, small-range strain gauge sensors are used. Different types of sensors may be used depending on the location of the temperature or pressure sensor (e.g., in a material supply module, flow distribution plate, or inside or near a nozzle).

[0135] In some embodiments, one or more pressure sensors are connected to a computer system that operates a material supply module to pressurize the printing material to a desired pressure in response to the pressure reported by the pressure sensors. In some embodiments, the printing pressure is within approximately 0.05 MPa of the desired pressure. In some embodiments, the material supply module includes a piston mechanism, a screw mechanism (single-screw, double-screw, triple-screw, quadruple-screw, quintuple-screw, octuple-screw), a screw pump mechanism, a gear mechanism, a plunger pump mechanism (e.g., a valveless measuring pump mechanism), or any combination thereof. In some embodiments, one or more heaters include a single-piston mechanism, a single-screw mechanism, a double-screw mechanism, or any combination thereof. In some embodiments, the pressurizing device of the material supply module includes a piston mechanism, a screw mechanism, a screw pump mechanism, a gear mechanism, a plunger pump mechanism (e.g., a valveless measuring pump mechanism), or any combination thereof.

[0136] In some embodiments, the system includes a pressure-closed-loop control system that adjusts the material supply module (e.g., the rotational speed of a screw mechanism) based on pressure readings (e.g., from pressure sensors in a flow distribution plate or nozzle) to achieve and maintain a target pressure. In some embodiments, the average of pressure readings from multiple pressure sensors is used.

[0137] In some embodiments, the pressure sensor is configured to detect the pressure of material in the nozzle or in a feed channel adjacent to the nozzle. In some embodiments, the pressure sensor is positioned within the nozzle or adjacent to the feed channel and close to the nozzle. The pressure sensor can work with a pressure controller in a closed-loop feedback system to provide a substantially constant pressure to the material in the device. For example, if the pressure sensor detects a drop in pressure, the feedback system can signal the pressure controller to increase the pressure of the material (e.g., by lowering the piston, increasing the air pressure in the barrel, turning the pressure screw, etc.). Similarly, if the pressure sensor detects an increase in pressure, the feedback system can signal the pressure controller to decrease the pressure of the material (e.g., by raising the piston, decreasing the air pressure in the barrel, turning the pressure screw, etc.). The constant pressure ensures that when the nozzle is in the open position, the molten material in the device is ejected at a constant rate through the nozzle's extrusion port. However, when the nozzle is in the closed position, a certain increase in pressure (e.g., by raising the piston, decreasing the air pressure in the barrel, or turning the pressure screw) can cause molten material to leak through the nozzle. Furthermore, a feedback system including a pressure sensor and pressure controller maintains a nearly constant pressure within the system when the microscrew is repositioned from the open to the closed position, or from the closed to the open position. This minimizes the "ramp-up" of the extrusion rate when the sealing needle is positioned from the closed to the open position, as there is no need to ramp up the pressure of the material within the system. The feedback system can operate using a proportional-integral-derivative (PID) controller, a bang-bang controller, a predictive controller, a fuzzy control system, an expert system controller, or any other suitable algorithm. In some embodiments, the sample rate of the pressure sensor is approximately 20 ms or less, such as approximately 10 ms or less, approximately 5 ms or less, or approximately 2 ms or less.In some embodiments, the pressure is controlled to be within 0.01 MPa, 0.05 MPa, 0.1 MPa, 0.2 MPa, 0.5 MPa, or 1 MPa of the target pressure.

[0138] Further details regarding the additional material supply module and some other features of the printing system can be found in PCT / CN2018 / 071965, titled "PRECISION PHARMACEUTICAL 3D PRINTING DEVICE," and WO2018 / 210183, titled "3D PRINTING DEVICE AND METHOD." The entire content is incorporated therein.

[0139] Figure 1B shows schematic diagrams of two exemplary sets of print heads according to several embodiments. In the illustrated examples, the two sets of print heads are set A and set B, each set comprising eight print heads sharing the same support frame. For example, all eight print heads in set B share the same support frame 108. Sets A and B can form part of an additive manufacturing system 100 (Figure 1A).

[0140] In some embodiments, the material supply module 102 of the additive manufacturing system 100 can supply pressurized and molten material to the print head shown in Figure 1B via a supply channel 106. The supply channel 106 may be identical to, a part of, or an extension of the supply channel 104 shown in Figure 1A.

[0141] Pressurized and molten printing material can be transported to the flow distribution module 110 via the supply channel 106. In some embodiments, a sealing mechanism is provided at the inlet of the flow distribution module 110. The flow distribution module 110 comprises a flow distribution plate having branching channels (not shown) configured to divide a single flow of printing material (e.g., supplied by a material supply module) into multiple flows. In some embodiments, the flow distribution module 110 can divide a single flow into two flows, the two flows into four flows, the four flows into eight flows, the eight flows into sixteen flows, and the sixteen flows into thirty-two flows. In some embodiments, the flow distribution module can directly divide a single flow into two, three, four, five, ..., or n flows. In some embodiments, the flow distribution module can divide a single flow into three flows, the three flows into nine flows, and the nine flows into twenty-seven flows.

[0142] In some embodiments, the flow distribution module 110 includes a flow distribution plate, a temperature control mechanism, a pressure sensor, a temperature sensor, or any combination thereof. The flow distribution plate has a single channel connected to a supply channel of a material supply module to receive a single flow of printing material. The flow distribution plate has a plurality of branching channels configured to divide the single flow into a plurality of flows, each discharged through a plurality of nozzles of a plurality of print heads. Each nozzle is configured to discharge a flow of printing material under control (e.g., via a microscrew mechanism, via a needle valve mechanism).

[0143] Figure 12A shows a schematic diagram of another exemplary additive manufacturing system (e.g., a 3D printing system) 1200 according to some embodiments of the present disclosure. System 1200 comprises two printhead modules 1202 and 1204. Each printhead module comprises one or more printheads. In the illustrated example, printhead module 1202 comprises four printheads for ejecting four flows, and similarly, printhead module 1204 comprises four printheads for ejecting four flows. In some embodiments, a printhead module may comprise any number of printheads, such as one, two, eight, or sixteen printheads.

[0144] In some embodiments, the printhead module is a separate unit that can be attached to or removed from the additive manufacturing system. For example, a user can assemble an additive manufacturing system by attaching any number of printhead modules (e.g., 2, 3, 4, 8, 16) to the system, thus making the number of printheads easily configurable. In another example, a user can assemble an additive manufacturing system by attaching a single printhead module to the system.

[0145] In some embodiments, printhead modules may have module-specific flow distribution plates. For example, printhead module 1202 may have a module-specific flow distribution plate so that the module can receive a single flow and divide it into four flows that are ejected by the four printheads within the module. Referring to Figure 12A, system 1200 has a system-wide flow distribution plate 1206 for dividing the single flow into two flows that are received by printhead modules 1202 and 1204, respectively. Furthermore, each printhead module has a module-specific flow distribution plate for further dividing the received single flow into four flows. Thus, system 1200 corresponds to eight printheads for ejecting eight flows. Printhead modules 1202 and 1204 may share the same push plate so that they can eject eight flows simultaneously and uniformly.

[0146] Figure 12B shows a schematic diagram of an exemplary additive manufacturing system (e.g., a 3D printing system) 1250 according to some embodiments of the present disclosure. The system has a flow distribution plate 1251 for the entire system. The flow distribution plate 1251 divides a single flow into two flows. Each of the two flows is further divided into two flows at junctions 1252 and 1262, respectively, thus generating four flows. Each of the four flows is further divided into two flows at junctions 1254, 1256, 1264, and 1266, respectively, thus generating eight flows. Each of the eight flows can be provided to a print head module. For example, if the print head module 1202 in Figure 12A is mounted to distribute eight flows, the system would have a total of 32 print heads for dispensing 32 flows.

[0147] Figure 1C shows exemplary configurations of channels within a flow distribution plate according to several embodiments. In each configuration, a single flow can be divided into multiple flows, which are discharged evenly (e.g., in terms of weight) through multiple nozzles. Due to the arrangement of channels and joints within the flow distribution plate, each of the multiple flows traverses a unique flow path that begins, for example, at an upper inlet to receive a single flow from a supply channel to the flow distribution plate and extends to the corresponding nozzle. In some embodiments, the flow paths of the multiple flows are geometrically symmetrical (e.g., equal length, equal geometric shape). In some embodiments, the flow paths of the multiple flows are not geometrically symmetrical, but even distribution is achieved by adjusting the diameter of the flow paths along different portions of the flow paths. In some embodiments, some or all of these joints are located on the same or substantially the same plane (e.g., the same XY plane). In some embodiments, some or all of these joints are located on different planes (e.g., different XY planes).

[0148] In some embodiments, the nozzles can be arranged in a natural equilibrium layout or a rheological equilibrium layout. The flow distribution plate can be configured to divide a single flow into four or eight flows. The flow distribution plate can be configured to divide a single flow into sixteen or thirty-two flows via one or more 1:4 or 1:8 subplates. The flow distribution plate can be configured to divide a single flow into three, five, or seven flows via a rheological equilibrium layout.

[0149] In some embodiments, the flow distribution plate can be divided into multiple components (e.g., horizontally, vertically, and / or diagonally). For example, the flow distribution plate may comprise an upper plate and a lower plate. The multiple components can be held together by screws. When disassembled, each individual component exposes the inner surface of one or more channels and joints within the flow distribution plate, thus making it easier to clean the channels and joints of the flow distribution plate.

[0150] In some embodiments, the pressure in the channels of the flow distribution plate can be 0 to 20 MPa during operation (e.g., 0 to 5 MPa, 0 to 10 MPa, 0 to 20 MPa). The time required for the material to traverse the flow distribution plate can be 5 minutes to 5 hours. In some embodiments, the discharge rate at the nozzle can be 0.1 to 10 μL / second (e.g., 2 to 3 μL / second).

[0151] In some embodiments, the flow distribution plate includes a temperature control mechanism for maintaining the temperature of the flow distribution plate at a desired level. In some embodiments, the temperature control mechanism includes one or more heaters and one or more coolers, the heaters and coolers configured to operate in conjunction to maintain the internal temperature of the flow distribution plate.

[0152] One or more heaters can be placed within or adjacent to the flow distribution plate. For example, the flow distribution plate has internal slots for housing one or more heaters (e.g., wires, plates) made of a material with high thermal conductivity. One or more heating wires extend through the internal slots within the flow distribution plate. The flow distribution plate may have multiple rows and columns of internal slots to allow the heating wires to be evenly distributed throughout the plate so that the temperature inside the plate is maintained at a constant temperature.

[0153] One or more cooling tubes can be positioned within or adjacent to the flow distribution plate. In some embodiments, the temperature control device achieves cooling via water circulation. For example, a pair of cooling plates, each having an internal channel for water flow, are positioned above and below the flow distribution plate, so that water flow, air, coolant, etc., can be generated in close proximity to the flow distribution plate to regulate the plate's temperature. In some embodiments, the flow distribution plate includes internal slots for accommodating one or more coolers within the flow distribution plate. For example, the flow distribution plate and the cooling plates above and below it all have inlets for receiving coolant.

[0154] In some embodiments, the flow distribution plate includes one or more temperature sensors connected to a computer system that operates one or more heaters and coolers in response to temperatures reported by one or more temperature sensors.

[0155] In some embodiments, the flow distribution plate comprises one or more pressure sensors configured to detect the pressure of the printing material within the channels of the flow distribution plate. In some embodiments, the pressure sensors are positioned in close proximity to the flow distribution plate (e.g., around corners, periphery, or center) or within the channels of the flow distribution plate. In some embodiments, strain sensors are used.

[0156] Referring to Figures 1A and 1B, as will be described in detail below, each of the multiple flows can be ejected by the corresponding print head of system 100 to generate an object (e.g., a 3D printed pharmaceutical dosage unit) on the printing platform.

[0157] Figure 2A shows a schematic diagram of an exemplary set of print heads 200 according to several embodiments. In the illustrated example, the set comprises eight print heads sharing the same support frame 208. Set 200 can be either set A or set B, which can form part of additive manufacturing system 100 (Figure 1A). A top view of set 200 is presented in Figure 2B.

[0158] Referring to Figure 2A, the printhead set comprises a drive module 202. In the illustrated example, the drive module 202 comprises eight rotary motors 204. The eight rotary motors are configured to control eight printheads, each. Specifically, each rotary motor can control the rotational speed of the corresponding microscrew of a microscrew printhead. In some embodiments, the drive module 202 includes rotary motors shared among multiple (e.g., eight) printheads, and the rotary motors can drive the rotation of multiple microscrews simultaneously (e.g., via gears and / or belts).

[0159] The drive module further comprises an actuator 206. In the illustrated example, the actuator is configured to control eight print heads simultaneously. Specifically, the actuator can generate the speed and acceleration of the vertical movement of the microscrews, and thus control the opening and closing of the nozzles and the travel displacement of the microscrews (thereby allowing the nozzles to be fully open, fully closed, or partially open by any amount). In the illustrated example, the actuator can control eight microscrews simultaneously via a push plate mechanism 210, thereby allowing the actuator's movement to be converted to all eight microscrews at once. In some embodiments, a separate actuator can be assigned to each microscrew print head.

[0160] In some embodiments, the motor and actuator within the drive module include one or more stepping motors. The drive module can control the actuator and the rotary motor independently, or it can perform combined control of the actuator and the rotary motor. For example, the drive module can independently control the rotary motor (e.g., rotational speed) without driving the actuator so that the microscrew rotates without traveling vertically. The drive module can perform combined control by simultaneously controlling the rotary motor (e.g., rotational speed) and the actuator (e.g., travel speed), thereby causing the microscrew to rotate while moving vertically.

[0161] In some embodiments, the actuator can be a pneumatic actuator, a mechanical actuator, an electromagnetic actuator, a hydraulic actuator, or an electric motor. The electric motor can control the vertical movement (e.g., velocity, acceleration) and displacement of the microscrew.

[0162] The printhead set further comprises a flow distribution module 212. The flow distribution module comprises a base plate 213. In some embodiments, the flow distribution plate and at least a portion of the microscrew printheads are housed within the base plate. In the illustrated example, the flow distribution module can divide a single flow of printing material into multiple flows. The flow distribution module 212 can be part of a larger flow distribution module (e.g., the distribution modules shown in Figures 1A and 1B). For example, the flow distribution module 212 may include subplates that form part of a larger flow distribution plate. The flow distribution modules in Figures 1A and 1B can first divide a single flow (e.g., a flow carried by the supply channel 104) into four flows, one of which is further divided into eight flows ejected by the eight printheads in Figure 2A.

[0163] Figures 2C and 2D show cross-sectional views of a set of eight print heads 200 according to several embodiments, respectively. Referring to Figure 2D, a rotary motor 204 is configured to control the rotational speed of a microscrew 230 via a motor adapter shaft 220. An actuator is configured via a conversion shaft 222 to control the vertical speed and acceleration as well as the travel displacement of the microscrew (which allows the nozzle to be fully open, fully closed, or partially open by any amount). The conversion shaft 222 is coupled to the microscrew 230 via a conversion shaft coupling 226 and a bearing seat 224.

[0164] Figure 2E shows a cross-sectional view of a single print head according to several embodiments. A rotary motor 204 is configured to control the rotational speed of a microscrew 230 via a motor adapter shaft 220. The motor adapter shaft 220 is coupled to the microscrew 230 using a coupling mechanism so that the rotary motor can drive the microscrew. In the illustrated example, the coupling mechanism is a cross connector 221. The coupling mechanism provides some flexibility in the coupling between the microscrew and the motor adapter shaft on the z-axis, allowing for slight misalignment between the microscrew and the motor adapter shaft.

[0165] The actuator 206 is configured to control the speed of vertical movement and the position of the microscrew via a conversion shaft 222. The conversion shaft 222 is coupled to the microscrew 230 via a connecting shaft adapter plate 223, a conversion shaft coupling 226, and a bearing seat 224. In the illustrated example, the flow of printing material is transported through the channel 240 and discharged by the microscrew 230.

[0166] Figure 2F shows cross-sectional views of four print heads according to several embodiments. For each print head, a cross connector (e.g., 242) is used to connect the rotary motor and microscrew. The cross connector provides some flexibility in the coupling between the microscrew and the motor adapter shaft on the z axis. The cross connector also eliminates the need for perfect concentric alignment of the motor adapter shaft and microscrew, and allows for slight misalignment between the microscrew and the motor adapter shaft. In some embodiments, the connection mechanism may include a universal connector.

[0167] The embodiment in Figure 2F differs from the embodiment in Figure 2D (where the conversion shaft 222 and microscrew 230 are two separate components coupled together via the conversion shaft coupling 226). In the embodiment of Figure 2F, the conversion shaft and microscrew are integrated as a single component, thus reducing the number of coupling components required, improving the robustness of the assembly, and reducing misalignment when the system is in operation.

[0168] Figure 3A shows exemplary cross-sectional views of two microscrew print heads according to several embodiments. In some embodiments, the two microscrew print heads may be the two heads shown in Figure 2D. In the illustrated example, the two print heads are identical.

[0169] Referring to Figure 3A, each microscrew printhead comprises a microscrew (e.g., microscrew 302). The microscrew comprises a threadless stem portion, a threaded stem portion below the threadless stem portion (e.g., 302a), and a conical head portion (e.g., 302b). The threaded stem portion is threaded along its length for the purpose of volume measurement (i.e., weighing). In some embodiments, the threaded stem portion is threaded identically along its entire length, thus forming a uniform groove (e.g., in width, depth, and curvature) from the top of the threaded portion to the distal end of the threaded portion.

[0170] Each microscrew print head further comprises a sleeve (e.g., sleeve 306) and a nozzle (e.g., nozzle 308). The sleeve forms a vertical chamber from which the microscrew can move and rotate vertically. As shown in Figure 3A, the distal end of the nozzle has a conical inner surface and an outlet port for ejecting the printing material. To close the outlet port, the microscrew can be driven downward (e.g., via an actuator) until the conical head portion of the microscrew contacts the conical inner surface of the nozzle. In this way, the outlet port is sealed and the nozzle stops ejecting the printing material.

[0171] In some embodiments, the microscrew printhead may include a z-axis positioning sealing ring 310 (or inlet sealing ring) between the sleeve 306 and the nozzle 308. The z-axis positioning sealing ring is configured to adjust the vertical position of the nozzle so that the nozzle height matches that of the other nozzles in the system. In some embodiments, the sealing ring may be made of fluororubber, polytetrafluoroethylene, Teflon®, Iglidur, or any combination thereof.

[0172] In some embodiments, each microscrew print head further comprises a heating sleeve (e.g., 312), an insulating sleeve (e.g., 314), a temperature sensor, a pressure sensor, or any combination thereof. In some embodiments, the heating sleeve, insulating sleeve, temperature sensor, and / or pressure sensor may be located at each nozzle or around each nozzle.

[0173] In some embodiments, one or more heaters are positioned outside the nozzle. These one or more heaters may include a heating sleeve, a heating ring, a heating rod, or any combination thereof. The heating power can be 30-50W.

[0174] In some embodiments, the insulating sleeve includes an insulating material (e.g., PEEK, polytetrafluoroethylene).

[0175] Referring to Figure 3A, the flow distribution module comprises a flow distribution plate, which comprises a flow channel 301. The flow channel 301 delivers two flows of molten and pressurized printing material to two microscrew print heads, respectively. A runner sealing ring 330 is positioned in the flow channel 301 around the inlet 332 of the microscrew print head, forming an additional seal between the inlet of the microscrew print head and the flow distribution plate.

[0176] In the illustrated example, the flow distribution plate comprises an upper plate 320 and a lower plate 322. The two plates can be held together by screws. When disassembled, each individual plate exposes the inner surface of one or more channels and joints within the flow distribution plate, thus facilitating easier cleaning of the channels and joints of the flow distribution plate. The flow distribution module may include a temperature control system, such as upper heating plates 324 and 326.

[0177] Figure 3B shows a cross-sectional view of an exemplary microscrew printhead according to several embodiments. The microscrew printhead comprises a microscrew 302. The microscrew 302 comprises a threaded stem portion and a conical head portion 302b located below the stem portion. The threaded stem portion is threaded along its entire length for the purpose of volume measurement. In some embodiments, the threaded stem portion is threaded identically along its entire length, thus forming a uniform groove (e.g., in width, curvature, and depth) from the top to the distal end of the threaded stem portion.

[0178] Figure 3D shows a cross-sectional view of an exemplary microscrew print head according to several embodiments. In the illustrated example, the threads of the stem portion of the microscrew are rectangular. Furthermore, the threads have varying widths along the length of the threaded stem portion. As shown, the rectangular threads toward the top of the threaded stem portion are wider than the threads toward the bottom of the threaded stem. The illustrated configuration allows for rapid input of printing material and thus improves printing speed. It should be understood that the threads can have any shape, such as semicircular, cylindrical, conical, trapezoidal, rectangular, and triangular.

[0179] The microscrew print head further comprises a sleeve 306 and a nozzle 308. The sleeve has a vertical chamber from which the microscrew can move and rotate vertically. As shown in Figure 3B, the distal end of the nozzle 308 has a conical inner surface 308a and an outlet port 308b for ejecting the printing material. To close the outlet port, the microscrew 302 can be driven downward (e.g., via an actuator) until the conical head portion 302b of the microscrew contacts the conical inner surface 308b of the nozzle. Thus, the nozzle stops ejecting the printing material.

[0180] In some embodiments, the microscrew print head may include a z-axis positioning sealing ring 310 between the sleeve 306 and the nozzle 308. The z-axis positioning sealing ring is configured to adjust the vertical position of the nozzle.

[0181] In the example shown in Figure 3B, when the microscrew printing header is in the closed position, a space exists within the nozzle between the conical inner surface 309a and the distal end of the microscrew. In some embodiments, the distal end of the microscrew can be fitted into the nozzle such that there is little or no space when the nozzle is closed, as shown in Figure 3C. In this way, little or no residue remains in the nozzle when it is closed, making it possible to accurately track the discharge volume.

[0182] Figure 3C shows a cross-sectional view of another exemplary microscrew printhead according to several embodiments. The distal end of the microscrew can be fitted to the nozzle such that there is little to no space between the conical inner surface 309a and the microscrew within the nozzle / sleeve when the microscrew printhead is in the closed position. A fixing nut is configured to couple the nozzle. As shown, the microscrew printhead further comprises an inlet sealing ring 330, an inlet 332, a microscrew sleeve 306, an insulating sleeve 314, and a heating sleeve 312, as described above. As shown in Figure 3A, the microscrew sleeve 306 is integrated with the base plate so that the XY position of the nozzle can be fixed. In some embodiments, the inlet sealing ring contains polytetrafluoroethylene. The inlet sealing ring 330 forms a flexible coupling mechanism between the flow distribution plate and the sleeve to prevent XY movement of the nozzle caused by expansion of the flow distribution plate (e.g., due to heat).

[0183] In some embodiments, the taper angle of the conical head portion of the microscrew (e.g., 302) is less than or equal to the taper angle formed by the conical inner surface of the nozzle. In some embodiments, the taper angle of the conical head portion of the microscrew is 60° (e.g., 40°) or less. In some embodiments, the ratio of the taper angle formed by the conical inner surface of the nozzle to the taper angle of the conical head portion is equal to 1:1 to 4:1, or equal to 1:1 to 3:1, or equal to 1:1 to 2:1, or 1:1 to 2:1.

[0184] In some embodiments, the conical head portion of the microscrew is frustoconical or truncated cone. In some embodiments, the conical head portion of the microscrew is configured to fit onto the conical inner surface of a nozzle via one or more matching patterns or structures.

[0185] In some embodiments, the length of the threaded stem portion of the microscrew is equal to or is between 10 and 80 mm (e.g., 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 70 mm).

[0186] In some embodiments, the diameter of the threaded stem portion of the microscrew is equal to or between 1 and 10 mm (e.g., 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm) or 1 to 10 mm.

[0187] In some embodiments, the diameter of the nozzle opening is 0.1 to 1 mm.

[0188] In some embodiments, the microscrew can be raised to any desired height to open the nozzle. For example, the microscrew can be raised by 0.05 to 1 mm (e.g., 0.1 mm, 0.2 mm, 0.3 mm).

[0189] After the nozzle opens, the rotation speed can be set to a constant speed to extrude the printing material in a constant volume. The rotation speed can be selected based on the desired output volume (e.g., 1-260 revolutions / min, 3-5 revolutions / min, 6-12 revolutions / min, 13-20 revolutions / min).

[0190] In some embodiments, the printing material is melted at 50°C to 400°C by a material supply module. In some embodiments, the printing material is extruded by a nozzle at 50°C to 400°C. In some embodiments, the printing material is a non-filamentary material, and the viscosity of the printing material when extruded by the nozzle is 800 Pa·s or higher. In some embodiments, the printing material includes a pharmaceutically acceptable material, an inert material, or a combination thereof.

[0191] Figure 14A shows a cross-sectional view of another exemplary microscrew printhead according to several embodiments. In some embodiments, the microscrew printhead is part of a printhead module (e.g., module 1450 in Figure 14B). As described herein with reference to Figures 12A-12B, the printhead module can be a separate unit that can be mounted on and removed from a toxic manufacturing system. Furthermore, each module may have its own module-specific flow distribution plate.

[0192] Referring to Figure 14A, the module-specific distribution plate includes an upper plate 1420 and a lower plate 1422. During operation, the upper and lower plates are coupled together to form channels for dividing and distributing the flow. In some embodiments, the lower plate 1422, sleeve 1406, and base plate are integrated and do not move relative to each other, thus fixing the XY position of the nozzle. Integration allows for better sealing and prevents leakage within the module (e.g., from the flow channels).

[0193] Referring to Figure 14A, the microscrew comprises a distal portion having three parts: a threaded stem portion, a tapered unthreaded central portion (indicated as "H2"), and a conical head (indicated as "H1"). In some embodiments, the distal portion can be identical in size and shape to the corresponding portion shown in Figure 3B. In some embodiments, the ratio of H2 to H1 can be 1 to 5. The tapered unthreaded central portion provides some elasticity to the microscrew, allowing the distal end of the microscrew to deform slightly along the X and Y directions when pressure is applied. Thus, when the conical head contacts the nozzle, the conical head can be more properly aligned with the nozzle, thus achieving a better seal and preventing leakage.

[0194] The microscrews described herein may be threaded in any way, such as single-start or multi-start. Multi-start screws may have double, triple, or quadruple threads. Multi-start screws allow the printing material to be introduced to the print head at a more consistent speed (e.g., by the rotation of the microscrew), which can improve the quality and precision of the printing material.

[0195] Figure 4 shows an exemplary process 400 of additive manufacturing via a microscrew print head according to several embodiments. In process 400, several blocks are optionally combined, the order of several blocks is optionally changed, and several blocks are optionally omitted. In some examples, additional steps may be performed in combination with process 400. Thus, the operations illustrated (and described in more detail below) are essentially exemplary and should not be considered limiting.

[0196] In block 402, the system raises the microscrew to open the nozzle exit port. In block 404, the system rotates the microscrew (e.g., via a rotary motor) to introduce the molten and pressurized printing material into the groove of the threaded stem portion of the microscrew. For example, as shown in Figure 3C, the flow of molten and pressurized printing material can be introduced through the inlet 332. In some embodiments, the vertical position of the microscrew is aligned with the inlet so that the uppermost threaded segment is exposed at the inlet. In this way, the printing material is fed to the head of the groove formed by the threads, and the printing material can move upward within the groove, preventing it from becoming a residue in the groove.

[0197] The molten and pressurized printing material is configured to flow through a groove toward the distal end of the nozzle. The faster the microscrew rotates, the more printing material is ejected from the nozzle. Based on the rotation speed and the known size of the groove, the system can calculate the volume of printing material ejected. As described above, the entire threaded stem portion is provided with identical threads throughout its entire length, thus forming a uniform groove (e.g., in width, depth, and curvature) that allows for easy calculation of the ejected volume.

[0198] At the end of a printing session, in block 404, the system lowers the microscrew so that the conical inner surface of the nozzle contacts the conical head portion of the microscrew, closing the exit port and stopping the ejection of printing material from the nozzle. In some embodiments, the contact is surface-to-surface contact, and therefore the impact on the components when contact occurs is reduced. In some embodiments, while the microscrew is lowering, its rotation is also controlled and slowed down to reduce the amount of printing material ejected.

[0199] In some embodiments, when the printing material is introduced through the inlet 332, the printing material is already melted and pressurized to a desired level. According to the documentation, the threaded stem portion of the microscrew is uniformly threaded along its entire length, solely for the purpose of tracking the discharge volume.

[0200] In some embodiments, the method may further include adjusting the speed and acceleration of the vertical movement of the microscrew via an actuator to control the travel displacement of the microscrew (thereby allowing the nozzle to be fully open, fully closed, or partially open by any amount). In some embodiments, the method further includes adjusting the rotational speed of the microscrew via a rotary motor to control the volume of printing material being extruded. In some embodiments, the actuator and rotary motor are configured to drive the combined movement of the microscrew.

[0201] In some embodiments, the system rotates the microscrew in a first direction to eject the printing material. The system may rotate the microscrew in the opposite direction to the first direction to remove a certain amount of printing material from the distal end of the nozzle before lowering the microscrew to close the exit port.

[0202] In some embodiments, the system heats the printing material according to a ladder scheme. According to the ladder scheme, the printing material is heated to a first temperature in the material supply module, to a second temperature in the flow distribution model, and to a third temperature in the nozzle. In some embodiments, the first temperature is 50°C, the second temperature is 70°C, and the third temperature is 105°C. This reduces the likelihood of qualitative changes in the printing material due to prolonged heating.

[0203] In some embodiments, the system measures the pressure of the printing material at the distal end and / or inlet of the nozzle (e.g., inlet 332) and controls the pressure of the printing material via a closed-loop control system.

[0204] In some embodiments, the system ejects printing material onto a printing platform. A controller for the printing platform can be used to move the platform based on Cartesian, polar, or cylindrical coordinate systems. The system can synchronize the movement of the printing platform with the amount of printing material ejected by the nozzles to achieve high-precision printing.

[0205] Figure 5A shows an exemplary layout of a standardized multi-station printing system for pharmaceutical units according to several embodiments. Referring to Figure 5A, the multi-station printing system 500 comprises several printing stations 502A, 502B, 502C, and 502D. The printing stations are arranged in a linear fashion. In the top view shown in Figure 5A, each of stations 502A to 502D comprises a set of nozzles (32 nozzles) configured to print batches of products (e.g., batches of tablets) by discharging multiple flows of printing material onto a printing plate.

[0206] In some embodiments, each of the printing stations 502A to 502D is configured to move the printing plate along the x, y, and z axes with reference to a corresponding coordinate system. In some embodiments, the coordinate systems of the printing stations 502A to D are different from each other, and therefore the printing stations 502A to D can be controlled independently (for example, via one or more controllers).

[0207] Referring further to Figure 5A, the multi-station system 500 includes a plate transport mechanism 506. As shown in the figure, the plate transport mechanism 506 is configured to travel along channels 504A and 504B. The plate transport mechanism 506 operates in conjunction with the printing stations to move a printing plate from one printing station (e.g., 502A) to one of its two ends (as indicated by arrows 508A and 508B), and then transports the printing plate along either channel (as indicated by arrows 510A and 510B) to move the printing plate onto another printing station. In some embodiments, the operation of the printing stations and the plate transport mechanism is harmonized to maximize the production speed and minimize the idle time of the printing stations.

[0208] Multiple stations within system 506 can be arranged in other layouts. In some embodiments, multiple stations can be arranged around a circle or a square.

[0209] In some embodiments, the plate transfer mechanism may include one or more channels, which may be circular or square in shape, to transfer a print plate from one printing station to another. In some embodiments, the plate transfer mechanism may include one or more grippers and / or robotic arms for picking up a print plate from one printing station and moving the print plate to another printing station.

[0210] Figure 5B shows a partial side view of an exemplary multi-station system 500 according to several embodiments. The multi-station system 500 comprises several printing stations, including printing stations 502A and 502B. Printing station 502A comprises a printing platform 506A and a set of nozzles (e.g., an array of nozzles) positioned above the printing platform. During operation, the set of nozzles can simultaneously eject a set of flow of printing material onto a printing plate placed on the printing platform 506A to form a batch of product (e.g., pharmaceutical dosage units). Printing station 502B comprises one or more different sets of nozzles and operates similarly to printing station 502B. In some embodiments, printing stations 502A and 502B cooperate to produce the same batch of pharmaceutical dosage units. For example, at t0, printing station 502A prints a batch of pharmaceutical dosage unit shells onto a plate placed on the printing platform 506A. The plate is then transported to the printing station 502B (for example, via a plate transport mechanism) and placed on the printing platform 506B. At t1, the printing station 502B prints the internal components of the shell batch.

[0211] In some embodiments, the printing station 502A comprises a first material supply module for melting and pressurizing a first printing material, a first flow distribution module configured to evenly divide a single flow of the molten and pressurized first printing material into a first plurality of flows, and a first printing module comprising a set of needle valve print heads configured to discharge the first plurality of flows. The printing station 502B comprises a second material supply module for melting and pressurizing a second printing material, a second flow distribution module configured to evenly divide a single flow of the molten and pressurized second printing material into a second plurality of flows, and a second printing module comprising a set of microscrew print heads configured to discharge the second plurality of flows.

[0212] In some embodiments, each of the first and second printing modules is configured to be extendable to accommodate a different number of print heads. The print heads can work in cooperation with the corresponding flow distribution modules to eject the corresponding printing material.

[0213] In some embodiments, each of the two printing stations is configured to be extendable to accommodate different types of printing modules.

[0214] In some embodiments, the multi-station system further includes a set of jet / drop-on-demand printheads, a set of injection printheads, a set of inkjet printheads, or any combination thereof.

[0215] It is important to understand the advantages of the multi-station system described above. For example, different types of materials may be better suited to different types of print heads. Therefore, by accommodating different types of print heads, the system can optimally print on different types of materials.

[0216] The printing materials described herein may include viscous materials. In some embodiments, the printing material is a pharmaceutical material, a thermoplastic material, or a combination thereof. In some embodiments, the material is extruded from a nozzle at a temperature of about 25°C to about 400°C. In some embodiments, the viscosity of the material is 0.001 to 10000 Pa·s.

[0217] In some embodiments, the material is a non-filamentary material such as a powder, granules, gel, or paste. The non-filamentary material is melted and pressurized so that it can be extruded through the extrusion port of the nozzle. As further described herein, the pressure of particularly viscous materials is carefully controlled to ensure precise and accurate deposition of the material. The material can be melted within the material supply module using one or more heaters disposed within the material supply module, such as in the barrel containing the material, the feeding channel, and / or in or around the nozzle. In some embodiments, the melting temperature of the material is about 30°C or higher, such as about 60°C or higher, about 70°C or higher, about 80°C or higher, about 100°C or higher, about 120°C or higher, about 150°C or higher, about 200°C or higher, or about 250°C or higher. In some embodiments, the melting temperature of the material is approximately 400°C or less, such as approximately 350°C or less, approximately 300°C or less, approximately 260°C or less, approximately 200°C or less, approximately 150°C or less, approximately 100°C or less, or approximately 80°C or less. The material discharged from the nozzle can be discharged at a temperature above the melting temperature of the material. In some embodiments, the material is discharged at a temperature of approximately 50°C or more, such as approximately 60°C or more, approximately 70°C or more, approximately 80°C or more, approximately 100°C or more, approximately 120°C or more, approximately 150°C or more, approximately 200°C or more, or approximately 250°C or more. In some embodiments, the material is discharged at a temperature of approximately 400°C or less, such as approximately 350°C or less, approximately 300°C or less, approximately 260°C or less, approximately 200°C or less, approximately 150°C or less, approximately 100°C or less, or approximately 80°C or less.

[0218] The systems described herein are useful for accurately and precisely dispensing viscous materials. In some embodiments, the material has a viscosity of about 100 Pa·s or more when dispensed from the device, such as about 200 Pa·s or more, about 300 Pa·s or more, about 400 Pa·s or more, about 500 Pa·s or more, about 750 Pa·s or more, about 800 Pa·s or more, or about 1000 Pa·s or more. In some embodiments, the material has a viscosity of about 4000 Pa·s or less, about 3000 Pa·s or less, or about 2000 Pa·s or less, such as about 1000 Pa·s or less, about 750 Pa·s or less, about 500 Pa·s or less, about 400 Pa·s or less, about 300 Pa·s or less, or about 200 Pa·s or less.

[0219] In some embodiments, the printing material is a pharmaceutically acceptable material. In some embodiments, the material is inert or biologically inert. In some embodiments, the material is an erosive or bio-erosive material. In some embodiments, the material is a non-erosive or non-biologically erosive material. In some embodiments, the material is a pharmaceutically acceptable material. In some embodiments, the material comprises one or more thermoplastic materials, one or more non-thermoplastic materials, or a combination of one or more thermoplastic materials and one or more non-thermoplastic materials. In some embodiments, the material is a polymer or copolymer.

[0220] In some embodiments, the material includes a thermoplastic material. In some embodiments, the material is a thermoplastic material. In some embodiments, the material is or includes an erosive thermoplastic material. In some embodiments, the thermoplastic material is edible (i.e., suitable for personal consumption). In some embodiments, the thermoplastic material is selected from the group consisting of hydrophilic polymers, hydrophobic polymers, swellable polymers, non-swellable polymers, porous polymers, non-porous polymers, erosive polymers (such as soluble polymers), pH-sensitive polymers, natural polymers, wax-like materials, and combinations thereof. In some embodiments, the thermoplastic material is cellulose ether, cellulose ester, acrylic resin, ethylcellulose, hydroxypropyl methylcellulose, hydroxypropylcellulose, hydroxymethylcellulose, C 12 ~C 30 mono or diglycerides of fatty acids, C 12 ~C 30Fatty alcohols, waxes, poly(meth)acrylic acid, polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer 57 / 30 / 13, polyvinylpyrrolidone-co-vinyl acetate (PVP-VA), polyvinylpyrrolidone-polyvinyl acetate copolymer (PVP-VA) 60 / 40, polyvinylpyrrolidone (PVP), polyvinyl acetate (PVAc) and polyvinylpyrrolidone (PVP) 80 / 20, vinylpyrrolidone-vinyl acetate copolymer (VA64), polyethylene glycol-polyvinyl alcohol graft copolymer 25 / 75, kollicoatIR-Polyvinyl alcohol 60 / 40, polyvinyl alcohol (PVA or PV-OH), poly(vinyl acetate) (PVAc), poly(butyl methacrylate-co-(2-dimethylaminoethyl) methacrylate-co-methyl methacrylate) 1:2:1, poly(dimethylaminoethyl methacrylate-co-methacrylate ester), poly(ethyl acrylate-co-methyl methacrylate-co-trimethylammonium ethyl methacrylate chloride), poly(methyl acrylate-co-methyl methacrylate-co-methacrylic acid) 7: 3:1, poly(co-methyl methacrylate) 1:2, poly(co-ethyl acrylate) 1:1, poly(co-methyl methacrylate) 1:1, poly(ethylene oxide) (PEO), poly(ethylene glycol) (PEG), hyperbranched polyesteramide, hydroxypropyl methylcellulose phthalate, hypromellose phthalate, hydroxypropyl methylcellulose or hypromellose (HMPC), hydroxypropyl methylcellulose acetate succinate or hypromellose acetate Tate succinate (HPMCAS), poly(lactide-co-glycolide) (PLGA), carbomer, poly(ethylene-co-vinyl acetate), ethylene-vinyl acetate copolymer, polyethylene (PE), and polycaprolactone (PCL), hydroxylpropylcellulose (HPC), polyoxyl 40 hydrogenated castor oil, methylcellulose (MC), ethylcellulose (EC), poloxamer, hydroxypropyl methylcellulose phthalate (HPMCP), poloxamer, hydrogenated castor oil, hydrogenated soybean oil, glyceryl palmitostearate, carnauba These include waxes, polylactic acid (PLA), polyglycolic acid (PGA), cellulose butyrate acetate (CAB), polyvinyl acetate phthalate (PVAP), waxes, beeswax, hydrogels, gelatin, hydrogenated vegetable oils, polyvinyl acetal diethylaminolactate (AEA), paraffin, shellac, sodium alginate, cellulose phthalate acetate (CAP), gum arabic, xanthan gum, glyceryl monostearate, octadecanoic acid, thermoplastic starch, derivatives thereof (salts, amides, or esters thereof, etc.), or combinations thereof.

[0221] In some embodiments, the erosive material includes non-thermoplastic materials. In some embodiments, the non-thermoplastic material is non-thermoplastic starch, sodium starch glycolate (CMS-Na), sucrose, dextrin, lactose, microcrystalline cellulose (MCC), mannitol, magnesium stearate (MS), silica gel powder, titanium dioxide, glycerin, syrup, lecithin, soybean oil, tea oil, ethanol, propylene glycol, glycerol, Tween®, animal fat, silicone oil, cocoa butter, fatty acid glycerides, petrolatum, chitosan, cetyl alcohol, stearyl alcohol, polymethacrylic acid, non-toxic polyvinyl chloride, polyethylene, ethylene-vinyl acetate copolymer, silicone rubber, or a combination thereof.

[0222] Exemplary materials that can be used with the devices or methods described herein include, but are not limited to, poly(meth)acrylate copolymers (such as copolymers containing one or more aminoalkyl methacrylates, methacrylic acids, methacrylic acid esters, and / or copolymers sold under the trademark name Eudragit® RSPO) and hydroxypropyl cellulose (HPC). In some embodiments, the material contains a drug. In some embodiments, the material is mixed with the drug.

[0223] Further details of the printing system's features can be found in PCT / CN2018 / 071965, titled "PRECISION PHARMACEUTICAL 3D PRINTING DEVICE," WO2018 / 210183, titled "3D PRINTING DEVICE AND METHOD," U.S. Patent No. 10201503B1 (now U.S. Patent No. 10201503), titled "Precision pharmaceutical 3D printing device," PCT / CN2019 / 101621, titled "HIGH-THROUGHPUT AND HIGH-PRECISCION PHARMACEUTICAL ADDITIVE MANUFACTURING SYSTEM," and PCT / 2019 / 13733, both of which incorporate the entirety of these features.

[0224] Figure 7A shows another exemplary layout of 32 print heads according to several embodiments. The system can receive a flow of molten and pressurized printing material from the supply channel 704. The system comprises four support structures A, B, C, and D. For each support structure, a set of eight print heads share the support structure. Figure 7B shows a top view of the system.

[0225] Figure 7C shows side views of support structures according to several embodiments. Each support structure includes a flow distribution plate configured to divide a single flow into eight flows, which can be ejected through eight print heads.

[0226] Figures 8A-C show exemplary push-plate mechanisms according to several embodiments. The push-plate mechanism includes a push-plate 810, a cam mechanism 808 (including four cams), a sliding plate 806, a sliding track 812, and an actuator 802. During operation, the actuator 802 slides the sliding plate horizontally (e.g., via a ball screw) as indicated by the horizontal arrow in Figure 8B. The sliding plate is coupled to the cam mechanism, and therefore slides the cam mechanism horizontally.

[0227] The cam mechanism includes four cams, each containing a horizontally inclined slot for housing a pin coupled to the push plate 810. The push plate (along with the pin coupled to it) is fixed to a support structure so that it can move vertically but not horizontally. When the cam slides horizontally, the pin slides in the inclined slot, causing the push plate to move horizontally. In addition to converting the horizontal movement of the sliding plate into the vertical movement of the push plate, the cam mechanism can also amplify the pushing force. Thus, the push plate can move multiple microscrews in the array simultaneously. This enables synchronous and consistent movement of multiple microscrews in the array, thereby ensuring consistency and precision between products manufactured by the multiple microscrews.

[0228] Figure 13A shows another exemplary push-plate mechanism according to several embodiments. The push-plate mechanism comprises a push plate 1308, a sliding plate 1306, and an actuator 1302. The sliding plate 1306 includes two sliding tracks 1312a and 1312b. As shown, the two sliding tracks are inclined, not horizontal. The push plate 1308 includes supports configured to slide along the sliding tracks. For example, support 1314 is configured to slide along sliding track 1312a. Figure 13B presents a cross-sectional view of the push-plate mechanism.

[0229] During operation, actuator 1302 slides the sliding plate 1306 horizontally (e.g., via a ball screw) as indicated by the horizontal arrows in Figures 13A and 13B. The push plate can move vertically but not horizontally. Therefore, when the sliding plate 1306 slides toward the push plate 1308, the push plate 1308 effectively rises upward due to the inclined sliding track. Furthermore, when the sliding plate 1306 slides toward the push plate 1308, the push plate 1308 effectively descends due to the inclined sliding track. Thus, the push plate can move multiple microscrews in the array simultaneously. This enables synchronous and consistent movement of multiple microscrews in the array, thereby ensuring consistency and precision between products manufactured by the multiple microscrews.

[0230] Figures 13C and 13D show additional exemplary push-plate mechanisms similar to those shown in Figures 13A and 13B. In Figures 13C and 13D, two printhead modules 1362 and 1364 (similar to modules 1202 and 1204 in Figure 12A) share the same push-plate 1358, the same sliding plate 1356, and the same motor 1350. Modules 1362 and 1364 can be driven vertically using the same push-plate mechanisms described with reference to Figures 13A and B.

[0231] The mechanism described with reference to Figures 13A-D does not include a cam system and therefore reduces potential mechanical and hardware errors. Thus, this mechanism allows for more precise control of the vertical movement of the print head, and therefore improves the quality and accuracy of printed products.

[0232] Figure 9 shows a schematic diagram of an exemplary additive manufacturing system according to several embodiments of the present disclosure. The system includes a twin-screw extruder 902, a weight loss scale 904, a buffer piston 906, and a plurality of microscrew print heads 908. The twin-screw extruder 902 and the buffer piston 906 are part of a material supply module. During operation, the print material is introduced into the extruder 902, which melts the print material to a desired temperature. The molten print material is then transported to the buffer piston 906, which pressurizes the molten print material.

[0233] The buffer piston 906 can hold molten and pressurized printing material when the print head 908 is not ejecting printing material (for example, when changing the printing station below the print head 908). During operation, when changing the printing platform below the print head 908, the print head stops ejecting printing material, but the extrusion device 902 continues to receive and pressurize the molten printing material. The molten and pressurized printing material is held in the buffer piston 906 until printing resumes. In this way, it is not necessary to turn off the material supply module simply because printing is temporarily interrupted at the print head, and therefore it is not necessary to turn off, restart, and reinitialize the material supply module.

[0234] Embodiments of this disclosure enable the production of consistent objects using a single microscrew printhead. Using a microscrew printhead, a batch of 32 filaments was printed using a set of printing material (e.g., 60% Eudragit RSPO, 20% ethylcellulose ethose (EC), and 20% stearic acid). The set of printing material was heated to 100°C in the material supply module, to 105°C in the supply channel, and to 105°C in the printhead. The printhead is equipped with a stainless steel nozzle having an opening of 0.4 mm. The set of printing material was pressurized to 1 MPa. The pressure can be controlled by a pressure controller based on readings from a pressure sensor. The microscrew was raised by 0.5 mm and rotated at 1 r / s for 10 seconds. The weight of the tablets obtained in the batch is shown in Figure 10. As shown, the average weight of the 32 filaments is 12.32 mg.

[0235] Figure 11 shows exemplary output of exemplary additive manufacturing systems according to several embodiments. In some embodiments, one or more microscrew printheads were used to print different components of a pharmaceutical tablet (e.g., shell, core). In some embodiments, the same microscrew printhead was used to print all components of a pharmaceutical tablet.

[0236] The weights of the resulting tablets are shown in Figure 11. As shown in the figure, the additive manufacturing system printed two batches of pharmaceutical tablets. One batch contained 20 pharmaceutical tablets with an average weight of 204.32 mg, and the other batch contained 15 pharmaceutical tablets with an average weight of 208.13 mg.

[0237] In some embodiments, when the weight of the pharmaceutical tablet is less than 300 mg, the relative weight deviation is approximately ±10%, such as approximately ±9%, approximately ±8%, approximately ±7.5%, approximately ±7%, approximately ±6%, approximately ±5%, approximately ±4%, or approximately ±3%, or approximately ±2%, or approximately ±1%.

[0238] In some embodiments, when the weight of the pharmaceutical tablet is 300 mg or more, the relative weight deviation is approximately ±5%, such as approximately ±4% or less, approximately ±3% or less, approximately ±2% or less, approximately ±1% or less, etc.

[0239] Figure 6 shows an example of a computing device according to one embodiment. Device 600 can be a host computer connected to a network. Device 600 can be a client computer or a server. As shown in Figure 6, device 600 can be any suitable type of microprocessor-based device, such as a personal computer, workstation, server, or handheld computing device (portable electronic device). The device may include, for example, one or more of the following: a processor 610, an input device 620, an output device 630, storage 640, and a communication device 660. The input device 620 and output device 630 can generally correspond to the above input and output devices and can be connected to or integrated with the computer.

[0240] The input device 620 can be any suitable device that provides input, such as a touchscreen, keyboard or keypad, mouse, or voice recognition device. The output device 630 can be any suitable device that provides output, such as a touchscreen, haptic device, or speaker.

[0241] Storage 640 can be any suitable device that provides storage, such as electrical, magnetic, or optical memory, including RAM, cache, hard drive, or removable storage disk. Communication device 660 may include any suitable device that can send and receive signals over a network, such as a network interface chip or device. Computer components can be connected in any suitable way, such as via a physical bus or wirelessly.

[0242] The software 650, which is stored in the storage 640 and can be executed by the processor 610, may include, for example, programming to embody the functions of this disclosure (for example, as embodied in the device as described above).

[0243] The software 650 may also be stored and / or transported in any non-temporary computer-readable storage medium for use by or in connection with an instruction execution system, apparatus, or device, which can fetch instructions associated with the software from such instruction execution systems, apparatus, or devices and execute those instructions. In the context of this disclosure, the computer-readable storage medium may be any medium, such as storage 640, which may contain or store programming for use by or in connection with an instruction execution system, apparatus, or device.

[0244] The software 650 can also be propagated in any transport medium for use by or in connection with an instruction execution system, apparatus, or device, which can fetch instructions associated with the software from such instruction execution systems, apparatus, or devices and execute those instructions. In the context of this disclosure, the transport medium can be any medium that can communicate, propagate, or transport programming for use by or in connection with an instruction execution system, apparatus, or device. Transport-readable mediums may include, but are not limited to, wired or wireless propagating media of electrons, magnets, light, electromagnetics, or infrared rays.

[0245] Device 600 may be connected to a network, which can be any preferred type of interconnected communication system. The network can implement any preferred communication protocol and can be secured by any preferred security protocol. The network may include any preferred configuration of network links capable of transmitting and receiving network signals, such as wireless network connections, T1 or T3 lines, cable networks, DSL, or telephone lines.

[0246] Device 600 can implement any operating system suitable for operation over a network. Software 650 can be written in any suitable programming language such as C, C++, Java®, or Python. In various embodiments, application software embodying the functions of this disclosure can be deployed in different configurations, such as, for example, in a client / server configuration, or as a web-based application or web service via a web browser.

[0247] Exemplary Embodiments The present invention provides the following embodiments. 1. Additive manufacturing system comprising: a material supply module for melting and pressurizing a printing material; a microscrew print head comprising a microscrew having a threaded stem portion and a conical head portion, wherein the threaded stem portion has threads along its entire length for volume measurement; a sleeve; a nozzle having a nozzle whose distal end comprises a conical inner surface and an outlet port for discharging printing material, wherein the conical inner surface of the nozzle is configured to contact the conical head portion of the microscrew when the microscrew print head is in the closed position to stop the discharging of printing material from the nozzle; and a drive module comprising a rotary motor for driving the rotational motion of the microscrew and an actuator for driving the vertical motion of the microscrew. 2. The system according to Embodiment 1, further comprising a z-axis positioning sealing ring between the sleeve and the nozzle, wherein the z-axis positioning sealing ring is configured to adjust the vertical position of the nozzle. 3. The system according to Embodiment 1 or 2, wherein the microscrew print head further comprises a heating sleeve or a temperature sensor. 4. The system according to any one of embodiments 1 to 3, wherein the microscrew print head further comprises an insulating sleeve. 5. The system according to any one of embodiments 1 to 4, wherein the first taper angle of the conical head portion of the microscrew is less than or equal to the second taper angle formed by the conical inner surface of the nozzle. 6. The system according to Embodiment 5, wherein the first taper angle of the conical head portion of the microscrew is 60° or less. 7. The system according to Embodiment 5, wherein the ratio of the second taper angle to the first taper angle is equal to 1:1 to 4:1 or is 1:1 to 4:1, equal to 1:1 to 3:1 or is 1:1 to 3:1, or equal to 1:1 to 2:1 or is 1:1 to 2:1. 8. The system according to any one of embodiments 1 to 7, wherein the conical head portion of the microscrew has a frustoconical or truncated cone shape. 9. The system according to any one of embodiments 1 to 8, wherein the conical head portion of the microscrew is configured to fit into the conical inner surface of the nozzle via one or more matching patterns. 10. The system according to any one of embodiments 1 to 9, wherein the length of the threaded stem portion of the microscrew is equal to or is between 10 and 80 mm. 11. The system according to any one of embodiments 1 to 10, wherein the diameter of the threaded stem portion of the microscrew is equal to or is 1 to 10 mm. 12. The system according to any one of embodiments 1 to 11, wherein the material supply module comprises an extrusion device for melting printing material and a pressurizing device. 13. The system according to Embodiment 12, wherein the extrusion device includes a single-piston extrusion mechanism, a single-screw extrusion mechanism, a twin-screw extrusion mechanism, a conical twin-screw extrusion mechanism, or any combination thereof. 14. The system according to Embodiment 12, wherein the pressurizing device includes a piston extrusion mechanism, a single-screw extrusion mechanism, a screw pump mechanism, a gear mechanism, a plunger pump mechanism (e.g., a valveless measuring pump mechanism), or any combination thereof. 15. The system according to any one of embodiments 1 to 14, wherein the material supply module includes one or more temperature sensors for detecting the temperature of the molten printing material. 16. The system according to any one of embodiments 1 to 15, further comprising one or more pressure sensors in the flow channel or the inlet of the microscrew print head for detecting the pressure of the molten printing material. 17. The system according to any one of embodiments 1 to 16, wherein the entrance of the microscrew print head is aligned based on the uppermost threaded segment of the threaded stem portion of the microscrew. 18. The system according to embodiment 17, further comprising an inlet sealing ring at the inlet of the microscrew print head. 19. The system according to any one of embodiments 1 to 18, wherein the drive module is configured to independently control the actuator and the rotary motor. 20. The system according to any one of embodiments 1 to 19, wherein the drive module is configured to perform combined control of an actuator and a rotary motor. 21. The system according to any one of embodiments 1 to 20, wherein the actuator is a pneumatic actuator, a mechanical actuator, an electromagnetic actuator, a hydraulic actuator, or an electric motor. 22. The system according to Embodiment 21, wherein an electric motor is configured to control the speed and acceleration of the vertical movement of the microscrew and / or the travel displacement of the microscrew. 23. The system according to any one of embodiments 1 to 22, wherein a rotary motor is configured to control the rotational speed of a microscrew. 24. The system according to any one of embodiments 1 to 23, further comprising a cross connector or cardan shaft used for coupling. 25. The system according to any one of Embodiments 1 to 24, wherein the printing material is melted at 50°C to 400°C by a material supply module. 26. The system according to any one of Embodiments 1 to 25, wherein the printing material is ejected by a nozzle at a temperature of 50°C to 400°C. 27. The system according to any one of Embodiments 1 to 26, wherein the printing material is a non-filamentary material and the viscosity of the printing material when extruded by the nozzle is 800 Pa·s or more. 28. The system according to any one of Embodiments 1 to 27, wherein the printing material comprises a pharmaceutically acceptable material, an inert material, or a combination thereof. 29. The system according to any one of embodiments 1 to 28, further comprising a printing platform and a controller for moving the printing platform based on a Cartesian coordinate system, a polar coordinate system, or a cylindrical coordinate system. 30. Additive manufacturing method via a microscrew print head, the microscrew print head comprising: a microscrew having a threaded stem portion and a conical head portion; and a nozzle having a conical inner surface and an outlet port for discharging printing material at its distal end, the method comprising: raising the microscrew to open the outlet port of the nozzle; rotating the microscrew to introduce molten and pressurized printing material into a groove in the threaded stem portion of the microscrew, configured such that the molten and pressurized printing material flows toward the distal end of the nozzle; and lowering the microscrew such that the conical inner surface of the nozzle contacts the conical head portion of the microscrew to close the outlet port and stop the discharging of printing material at the nozzle. 31. The method according to Embodiment 30, further comprising melting and pressurizing the printing material. 32. The method according to embodiment 30 or 31, further comprising adjusting the speed and acceleration of the vertical movement of the microscrew and / or the travel displacement of the microscrew via an electric motor. 33. The method according to any one of embodiments 30 to 32, further comprising adjusting the rotational speed of a microscrew via a rotary motor to control the volume of printing material being extruded. 34. The method according to any one of embodiments 30 to 33, wherein an electric motor and a rotary motor are configured to drive the combined movement of a microscrew. 35. The method according to any one of embodiments 30 to 34, further comprising lowering the microscrew while reducing the rotational speed of the microscrew to close the outlet port. 36. The method according to any one of embodiments 30 to 35, wherein rotating the microscrew includes rotating the microscrew in a first direction, and the method further includes rotating the microscrew in the opposite direction to the first direction before lowering the microscrew to close the exit port, thereby removing a certain amount of printing material from the distal end of the nozzle. 37. The method according to any one of embodiments 30 to 36, further comprising coordinating the movement of the printing platform and the amount of printing material discharged by the nozzles. 38. The method according to any one of embodiments 30 to 37, further comprising heating the printing material according to a ladder scheme, wherein the printing material is heated to a first temperature in the material supply module, the printing material is heated to a second temperature in the flow distribution model, and the printing material is heated to a third temperature in the nozzle. 39. The method according to any one of embodiments 30 to 38, wherein the first temperature is 50°C, the second temperature is 70°C, and the third temperature is 105°C. 40. The method according to any one of embodiments 30 to 39, further comprising measuring the pressure of the printing material at the inlet of a flow channel or microscrew printhead and controlling the pressure of the printing material via a closed-loop control system. 41. The method according to any one of Embodiments 30 to 40, wherein the printing material is a non-filamentary material and the viscosity of the printing material when extruded by the nozzle is 800 Pa·s or more. 42. The method according to any one of embodiments 30 to 41, wherein a microscrew is controlled to manufacture a pharmaceutical dosage unit. 43. Additive manufacturing system comprising: a material supply module for melting and pressurizing a printing material; a flow distribution module comprising a flow distribution plate, the flow distribution plate comprising a plurality of channels for evenly dividing a single flow of molten and pressurized printing material into a plurality of flows; a plurality of microscrew print heads configured to discharge a plurality of flows, each of the plurality of microscrew print heads comprising a threaded stem portion and a conical head portion, the threaded stem portion having threads along its entire length for volume measurement; a sleeve; a nozzle, the distal end of which comprises a nozzle comprising a conical inner surface and an outlet port for discharging printing material, the conical inner surface of which is configured to contact the conical head portion of a microscrew when each microscrew print head is in a closed position to stop the discharge of printing material from the nozzle; and a drive module comprising one or more rotary motors for driving the rotational motion of the plurality of microscrews and one or more actuators for driving the vertical motion of the plurality of microscrews. 44. The system according to embodiment 43, wherein each microscrew print head further comprises a z-axis positioning sealing ring between the sleeve and the nozzle, the z-axis positioning sealing ring being configured to adjust the vertical position of the nozzle. 45. The system according to embodiment 43 or 44, wherein each microscrew print head further comprises a heating sleeve or a temperature sensor. 46. ​​The system according to any one of embodiments 43 to 45, wherein each microscrew print head further comprises an insulating sleeve. 47. The system according to any one of embodiments 43 to 46, wherein for each microscrew print head, the first taper angle of the conical head portion of the microscrew is less than or equal to the second taper angle formed by the conical inner surface of the nozzle. 48. The system according to embodiment 47, wherein the first taper angle of the conical head portion of the microscrew is 60° or less. 49. The system according to Embodiment 47, wherein the ratio of the second taper angle to the first taper angle is equal to 1:1 to 4:1 or is 1:1 to 4:1, equal to 1:1 to 3:1 or is 1:1 to 3:1, or equal to 1:1 to 2:1 or is 1:1 to 2:1. 50. The system according to any one of embodiments 43 to 49, wherein for each microscrew print head, the conical head portion of the microscrew is frustoconical or truncated cone. 51. The system according to any one of embodiments 43 to 50, wherein for each microscrew print head, the conical head portion of the microscrew is configured to fit into the conical inner surface of the nozzle via one or more matching patterns. 52. The system according to any one of embodiments 43 to 51, wherein for each microscrew print head, the length of the threaded stem portion of the microscrew is equal to or is 10 to 80 mm. 53. The system according to any one of embodiments 43 to 52, wherein for each microscrew print head, the diameter of the threaded stem portion of the microscrew is equal to or is between 1 and 10 mm. 54. The system according to any one of embodiments 43 to 53, wherein the material supply module comprises an extrusion device for melting printing material and a pressurizing device. 55. The system according to Embodiment 54, wherein the extrusion device includes a single-piston extrusion mechanism, a single-screw extrusion mechanism, a twin-screw extrusion mechanism, a conical twin-screw extrusion mechanism, or any combination thereof. 56. The system according to Embodiment 54, wherein the pressurizing device includes a piston extrusion mechanism, a single-screw extrusion mechanism, a screw pump mechanism, a gear mechanism, a plunger pump mechanism (e.g., a valveless measuring pump mechanism), or any combination thereof. 57. The system according to any one of embodiments 43 to 56, wherein the material supply module includes one or more temperature sensors for detecting the temperature of the molten printing material. 58. The system according to any one of embodiments 43 to 57, further comprising one or more pressure sensors on the flow distribution plate or inlet of the print head for detecting the pressure of molten printing material. 59. The system according to any one of embodiments 43 to 58, wherein for each microscrew print head, the inlet of the microscrew print head is aligned based on the uppermost threaded segment of the threaded stem portion of the microscrew. 60. The system according to any one of embodiments 43 to 59, wherein one or more rotary motors comprise multiple rotary motors, each of which is configured to control the rotational speed of each microscrew of a plurality of microscrew printheads. 61. The system according to any one of embodiments 43 to 60, comprising a single rotary motor configured to simultaneously control the rotational speed of microscrews of multiple microscrew printheads, wherein one or more rotary motors are also configured to control the rotational speed of microscrews of multiple microscrew printheads. 62. The system according to any one of embodiments 43 to 61, wherein the actuator includes a pneumatic actuator, a mechanical actuator, an electromagnetic actuator, a hydraulic actuator, or an electric motor. 63. The system according to any one of embodiments 43 to 62, wherein one or more actuators comprise a plurality of electric motors, each of which is configured to control the speed and acceleration of the vertical movement of each microscrew and / or the travel displacement of each microscrew. 64. The system according to embodiment 63, comprising a single electric motor configured to simultaneously control the vertical speed and acceleration of a plurality of microscrews and the travel displacement of a plurality of microscrews via a push plate mechanism. 65. The system according to embodiment 64, wherein the push plate mechanism includes a sliding plate, a push plate, and a cam mechanism. 66. The system according to embodiment 65, wherein the cam mechanism is configured to convert the horizontal movement of the sliding plate into the vertical movement of the push plate. 67. The system according to any one of embodiments 43 to 66, wherein the drive module is configured to independently control one or more actuators and one or more rotary motors. 68. The drive module performs combined control of one or more actuators and one or more rotary motors, as described in any one of embodiments 43 to 67. 69. The system according to any one of embodiments 43 to 68, wherein at least one of the one or more rotary motors and one or more actuators is a stepping motor. 70. The system according to any one of embodiments 43 to 69, further comprising a cross connector or cardan shaft used for coupling. 71. The system according to any one of embodiments 43 to 70, wherein the flow distribution module comprises a base plate, and the flow distribution plate and a plurality of microscrew print heads are arranged within the base plate. 72. The system according to embodiment 71, wherein the flow distribution plate comprises an upper plate and a lower plate. 73. The system according to embodiment 71, wherein the base plate and the sleeves for a plurality of microscrew print heads are integrated. 74. The system according to any one of embodiments 43 to 73, further comprising a temperature control system outside the flow distribution plate, wherein the temperature control system comprises a heating device and a cooling device. 75. The system according to any one of embodiments 43 to 74, wherein the inlet of the flow distribution plate is equipped with a sealing mechanism. 76. The system according to any one of embodiments 43 to 75, wherein the inlet of the microscrew print head is equipped with a sealing mechanism. 77. The system according to embodiment 76, wherein the sealing mechanism is a sealing ring. 78. The system according to any one of embodiments 43 to 77, wherein a plurality of microscrew print heads are arranged in a natural equilibrium layout or a rheological equilibrium layout. 79. The system according to any one of embodiments 43 to 78, wherein the flow distribution plate is configured to divide a single flow into four or eight flows. 80. The system according to embodiment 79, wherein the flow distribution plate is configured to divide a single flow into 16 or 32 flows via one or more 1:4 or 1:8 subplates. 81. The system according to any one of embodiments 43 to 80, wherein the flow distribution plate is configured to divide a single flow into three, five, or seven flows via a rheological equilibrium layout. 82. The system according to any one of embodiments 43 to 81, wherein the printing material is melted at 50°C to 400°C by a material supply module. 83. The system according to any one of embodiments 43 to 82, wherein the printing material is ejected by a nozzle at a temperature of 50°C to 400°C. 84. The system according to any one of Embodiments 43 to 83, wherein the printing material is a non-filamentary material and the viscosity of the printing material when extruded by the nozzle is 800 Pa·s or more. 85. The system according to any one of embodiments 43 to 84, wherein the printing material comprises a pharmaceutically acceptable material, an inert material, or a combination thereof. 86. The system according to any one of embodiments 43 to 85, further comprising a printing platform and a controller for moving the printing platform based on a Cartesian coordinate system, a polar coordinate system, or a cylindrical coordinate system. 87. Additive manufacturing method via a plurality of microscrew printheads, each of the plurality of microscrew printheads comprising: a microscrew having a threaded stem portion and a conical head portion; a nozzle having a conical inner surface and an outlet port for discharging printing material at its distal end, the method comprising: distributing a single flow of molten and pressurized printing material into a plurality of flows via a flow distribution plate; directing each of the plurality of flows to the microscrew heads of the plurality of microscrew printheads; raising the microscrew at each microscrew printhead to open the outlet port of the nozzle; rotating the microscrew to introduce the respective flow into the groove of the threaded stem portion of the microscrew, configured such that the molten and pressurized printing material flows toward the distal end of the nozzle; and lowering the microscrew to close the outlet port by bringing the conical inner surface of the nozzle into contact with the conical head portion, thereby stopping the discharge of printing material at the nozzle. 88. The method according to embodiment 87, further comprising melting and pressurizing the printing material. 89. The method according to embodiment 87 or 88, wherein an electric motor is configured to simultaneously control the vertical speed and acceleration of a plurality of microscrews and the travel displacement of a plurality of microscrews via a push plate mechanism. 90. The method according to any one of embodiments 87 to 89, wherein each of the multiple electric motors is configured to control the speed and acceleration of the vertical movement of each microscrew and the travel displacement of each microscrew. 91. The method according to any one of embodiments 87 to 90, wherein each of the multiple rotary motors is configured to control the rotational speed of its respective microscrew via a motor adapter shaft. 92. The system according to any one of embodiments 87 to 91, wherein a single rotary motor is configured to simultaneously control the rotational speed of multiple microscrews of a microscrew printhead via one or more gears and belts. 93. The method according to any one of embodiments 87 to 92, wherein the actuator and the rotary motor are configured to drive the compound movement of the microscrew. 94. The method according to any one of embodiments 87 to 93, further comprising lowering the microscrew while reducing the rotational speed of the microscrew to close the outlet port. 95. Rotating a microscrew includes rotating the microscrew in a first direction, and the method is The method according to any one of claims 87 to 94, comprising rotating the microscrew in the opposite direction to the first direction to remove a certain amount of printing material from the distal end of the nozzle before lowering the microscrew to close the exit port. 96. The method according to any one of embodiments 87 to 95, further comprising coordinating the movement of the printing platform and the amount of printing material discharged by the nozzles. 97. The method according to any one of embodiments 87 to 96, further comprising heating the printing material according to a ladder scheme, wherein the printing material is heated to a first temperature in the material supply module, the printing material is heated to a second temperature in the flow distribution model, and the printing material is heated to a third temperature in each nozzle. 98. The method according to Embodiment 97, wherein the first temperature is 50°C, the second temperature is 70°C, and the third temperature is 105°C. 99. The method according to any one of embodiments 87 to 98, further comprising measuring the pressure of the printing material at the inlet of a microscrew print head or in a flow distribution plate, and controlling the pressure of the printing material via a closed-loop control system. 100. The method according to any one of Embodiments 87 to 99, wherein the printing material is a non-filamentary material and the viscosity of the printing material when extruded by the nozzle is 800 Pa·s or more. 101. The method according to any one of embodiments 87 to 100, wherein multiple microscrew print heads are configured to manufacture pharmaceutical dosage units. 102. Additive manufacturing system, comprising: a first printing station comprising: a first printing station comprising: a first material supply module for melting and pressurizing a first printing material; a first flow distribution module configured to evenly divide a single flow of the molten and pressurized first printing material into a first plurality of flows; and a first printing module comprising: a second printing station comprising: a second material supply module for melting and pressurizing a second printing material; a second flow distribution module configured to evenly divide a single flow of the molten and pressurized second printing material into a second plurality of flows; and a second printing module comprising: a second printing module configured to discharge a second plurality of flows. 103. The system according to embodiment 102, wherein the first printing station and the second printing station are configured to print the same batch of products. 104. The system according to embodiment 102 or 103, wherein each of the first and second printing modules is configured to be extendable to accommodate a different number of print heads. 105. The system according to any one of embodiments 102 to 104, wherein each of the first and second printing stations is configured to be extendable to accommodate different types of printing modules. 106. The system according to any one of embodiments 102 to 105, further comprising a set of droplet-ejection printheads, a set of injection printheads, a set of inkjet printheads, or any combination thereof. 107. Multiple pharmaceutical tablets prepared using one or more microscrew printing heads of an additive manufacturing system by any one of the methods 30 to 42. 108. A plurality of pharmaceutical tablets according to Embodiment 107, wherein all pharmaceutical tablets weighing 300 mg or less have a relative deviation of ±7.5% or less. 109. A plurality of pharmaceutical tablets according to Embodiment 107, wherein all pharmaceutical tablets weighing 300 mg or more have a relative deviation of ±5% or less.

[0248] While the present disclosure and examples have been fully described with reference to the accompanying figures, it should be noted that various changes and modifications will be apparent to those skilled in the art. Such changes and modifications should be understood to be included within the scope of the disclosure and examples as defined by the claims.

[0249] For illustrative purposes, the above description has referred to specific embodiments. However, the above exemplary considerations are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in light of the above teachings. The embodiments described have been selected to best illustrate the principles of the methods and their practical applications. This will enable those skilled in the art to best utilize various modifications of the methods and various embodiments suitable for specific intended uses.

Claims

1. An additive manufacturing system, wherein the system is A material supply module for melting and pressurizing printing material, wherein the material supply module includes a heater for melting the printing material, Multiple microscrew print heads, Drive module and Equipped with, Each of the aforementioned plurality of microscrew print heads is Microscrew and Sleeves and Nozzle and Equipped with, The aforementioned microscrew is The threaded stem part, The conical head portion, The central portion between the threaded stem portion and the conical head portion Equipped with, The diameter of the central portion is smaller than that of the threaded stem portion, and the diameter of the central portion is larger than the maximum parameter of the conical head portion, the threaded stem portion is provided with grooves for material transmission and volume measurement, and the threaded stem portion has threads along its entire length for volume measurement, The distal end of the nozzle is The inner surface of the cone, An outlet port for ejecting the aforementioned printing material and Equipped with, The conical inner surface of the nozzle is configured to stop the ejection of the printing material from the nozzle by contacting the conical head portion of the microscrew when the microscrew print head is in the closed position. The aforementioned drive module is A rotary motor for driving the rotational motion of the aforementioned microscrew, An actuator for driving the vertical motion of the microscrew and A system that includes these features.

2. The system according to claim 1, further comprising a z-axis positioning sealing ring between the sleeve and the nozzle, wherein the z-axis positioning sealing ring is configured to adjust the vertical position of the nozzle.

3. The system according to any one of claims 1 to 2, further comprising a heating sleeve or a temperature sensor, wherein the plurality of microscrew print heads further comprises a heating sleeve or a temperature sensor.

4. The system according to any one of claims 1 to 3, wherein the plurality of microscrew print heads further comprises an insulating sleeve.

5. The system according to any one of claims 1 to 4, wherein the first taper angle of the conical head portion of the microscrew is less than or equal to the second taper angle formed by the conical inner surface of the nozzle.

6. The system according to claim 5, wherein the first taper angle of the conical head portion of the microscrew is 60° or less.

7. The system according to claim 5, wherein the ratio of the second taper angle to the first taper angle is 1:1 to 4:1, or 1:1 to 3:1, or 1:1 to 2:

1.

8. The system according to any one of claims 1 to 7, wherein the conical head portion of the microscrew is frustoconical or truncated cone.

9. The system according to any one of claims 1 to 8, wherein the material supply module comprises an extrusion device for melting the printing material and a pressurizing device.

10. The extrusion device comprises a single-piston extrusion mechanism, a single-screw extrusion mechanism, a twin-screw extrusion mechanism, a conical twin-screw extrusion mechanism, or any combination thereof, according to claim 9.

11. The system according to claim 9, wherein the pressurizing device comprises a piston extrusion mechanism, a single-screw extrusion mechanism, a screw pump mechanism, a gear mechanism, a plunger pump mechanism (e.g., a valveless measuring pump mechanism), or any combination thereof.

12. The system according to any one of claims 1 to 11, wherein the material supply module comprises one or more temperature sensors for detecting the temperature of the molten printing material.

13. The system according to any one of claims 1 to 12, further comprising one or more pressure sensors in the flow channel or the inlet of the plurality of microscrew print heads for detecting the pressure of the molten printing material.

14. The system according to any one of claims 1 to 13, wherein the entrance of the microscrew print head is aligned based on the uppermost threaded segment of the threaded stem portion of the microscrew.

15. The system according to claim 14, further comprising an inlet sealing ring at the inlet of the microscrew print head.

16. The system according to any one of claims 1 to 15, wherein the drive module is configured to independently control the actuator and the rotary motor.

17. The system according to any one of claims 1 to 16, wherein the drive module is configured to provide combined control of the actuator and the rotary motor.

18. The system according to any one of claims 1 to 17, wherein the actuator is a pneumatic actuator, a mechanical actuator, an electromagnetic actuator, a hydraulic actuator, or an electric motor.

19. The system according to claim 18, wherein the electric motor is configured to control the speed and acceleration of the vertical movement of the microscrew and / or the travel displacement of the microscrew.

20. The system according to any one of claims 1 to 19, wherein the rotary motor is configured to control the rotational speed of the microscrew.

21. The system according to any one of claims 1 to 20, further comprising a cross connector or cardan shaft used for coupling.

22. The system according to any one of claims 1 to 21, further comprising a printing platform and a controller, wherein the controller is for moving the printing platform based on a Cartesian coordinate system, a polar coordinate system, or a cylindrical coordinate system.

23. A method of additive manufacturing via multiple microscrew print heads, Each of the aforementioned plurality of microscrew print heads is Microscrew and Nozzle and Equipped with, The aforementioned microscrew is The threaded stem part, The conical head portion, The central portion between the threaded stem portion and the conical head portion Equipped with, The diameter of the central portion is smaller than that of the threaded stem portion, and the diameter of the central portion is larger than the maximum parameter of the conical head portion, and the threaded stem portion is provided with grooves for material transmission and volume measurement. The distal end of the nozzle is The inner surface of the cone, An outlet port for ejecting printing material and Equipped with, The aforementioned method, The printing material is melted using heating, and the printing material is pressurized. By raising the microscrew, the outlet port of the nozzle is opened, The process involves rotating the microscrew to introduce the molten and pressurized printing material into the groove of the threaded stem portion of the microscrew, wherein the molten and pressurized printing material is configured to flow toward the distal end of the nozzle. The conical inner surface of the nozzle contacts the conical head portion of the microscrew, thereby closing the outlet port and lowering the microscrew to stop the ejection of the printing material from the nozzle. Methods that include...

24. The method according to claim 23, further comprising adjusting the speed and acceleration of the vertical movement of the microscrew and / or the travel displacement of the microscrew via an electric motor.

25. The method according to any one of claims 23 to 24, further comprising controlling the volume of the printing material to be discharged by adjusting the rotational speed of the microscrew via a rotary motor.

26. The method according to any one of claims 23 to 25, wherein an electric motor and a rotary motor are configured to drive the combined movement of the microscrew.

27. The method according to any one of claims 23 to 26, further comprising closing the outlet port by lowering the microscrew while reducing the rotational speed of the microscrew.

28. Rotating the microscrew includes rotating the microscrew in a first direction. The method according to any one of claims 23 to 27, further comprising removing a certain amount of the printing material from the distal end of the nozzle by lowering the microscrew and rotating the microscrew in the opposite direction to the first direction before closing the outlet port.

29. The method according to any one of claims 23 to 28, further comprising moving the printing platform and adjusting the amount of printing material discharged by the nozzle.

30. The method further includes heating the printing material according to a ladder scheme, The printing material is heated to a first temperature in the material supply module. The printing material is heated to a second temperature in the flow rate distribution model. The method according to any one of claims 23 to 29, wherein the printing material is heated to a third temperature in the nozzle.

31. The method according to any one of claims 23 to 30, wherein the first temperature is 50°C, the second temperature is 70°C, and the third temperature is 105°C.

32. The method according to any one of claims 23 to 31, further comprising measuring the pressure of the printing material at the inlet of a flow channel or the plurality of microscrew print heads, and controlling the pressure of the printing material via a closed-loop control system.

33. The method according to any one of claims 23 to 32, wherein the printing material is a non-filamentary material, and the viscosity of the printing material when extruded by the nozzle is 800 Pa·s or more.

34. The method according to any one of claims 23 to 33, wherein the microscrew is controlled to produce a pharmaceutical dosage unit.

35. An additive manufacturing system, wherein the system is A material supply module for melting and pressurizing printing material, wherein the material supply module includes a heater for melting the printing material, A flow distribution module comprising a flow distribution plate, wherein the flow distribution plate comprises a plurality of channels for evenly dividing a single flow of the molten and pressurized printing material into a plurality of flows, Multiple microscrew print heads configured to discharge the aforementioned multiple flows, Drive module and Equipped with, Each of the aforementioned plurality of microscrew print heads is Microscrew and Sleeves and Nozzle and Equipped with, The aforementioned microscrew is The threaded stem part, The conical head portion, The central portion between the threaded stem portion and the conical head portion Equipped with, The diameter of the central portion is smaller than that of the threaded stem portion, and the diameter of the central portion is larger than the maximum parameter of the conical head portion, the threaded stem portion is provided with grooves for material transmission and volume measurement, and the threaded stem portion has threads along its entire length for volume measurement, The distal end of the nozzle is The inner surface of the cone, An outlet port for ejecting the aforementioned printing material and Equipped with, The conical inner surface of the nozzle is configured to stop the ejection of the printing material from the nozzle by contacting the conical head portion of the microscrew when the microscrew print head is in the closed position. The aforementioned drive module is One or more rotary motors for driving the rotational motion of the plurality of microscrews, One or more actuators for driving the vertical movement of the plurality of microscrews A system that includes these features.

36. The system according to claim 35, wherein each microscrew print head further includes a z-axis positioning sealing ring between the sleeve and the nozzle, the z-axis positioning sealing ring being configured to adjust the vertical position of the nozzle.

37. The system according to any one of claims 35 to 36, wherein each microscrew print head further comprises a heating sleeve or a temperature sensor.

38. The system according to any one of claims 35 to 37, wherein each microscrew print head further comprises an insulating sleeve.

39. The system according to any one of claims 35 to 38, wherein, for each microscrew print head, the first taper angle of the conical head portion of the microscrew is less than or equal to the second taper angle formed by the conical inner surface of the nozzle.

40. The system according to claim 39, wherein the first taper angle of the conical head portion of the microscrew is 60° or less.

41. The system according to claim 39, wherein the ratio of the second taper angle to the first taper angle is 1:1 to 4:1, or 1:1 to 3:1, or 1:1 to 2:

1.

42. The system according to any one of claims 35 to 41, wherein, for each microscrew printing head, the conical head portion of the microscrew is frustoconical or truncated cone.

43. The system according to any one of claims 35 to 42, wherein, for each microscrew print head, the conical head portion of the microscrew is configured to fit into the conical inner surface of the nozzle via one or more matching patterns.

44. The system according to any one of claims 35 to 43, wherein the material supply module comprises an extrusion device for melting the printing material and a pressurizing device.

45. The extrusion device comprises a single-piston extrusion mechanism, a single-screw extrusion mechanism, a twin-screw extrusion mechanism, a conical twin-screw extrusion mechanism, or any combination thereof, according to claim 44.

46. The pressurizing device comprises a piston extrusion mechanism, a single-screw extrusion mechanism, a screw pump mechanism, a gear mechanism, a plunger pump mechanism (e.g., a valveless measuring pump mechanism), or any combination thereof, according to claim 44.

47. The system according to any one of claims 35 to 46, wherein the material supply module comprises one or more temperature sensors for detecting the temperature of the molten printing material.

48. The system according to any one of claims 35 to 47, further comprising one or more pressure sensors at the flow distribution plate or the inlet of each microscrew print head for detecting the pressure of the molten printing material.

49. The system according to any one of claims 35 to 48, wherein, for each microscrew print head, the inlet of the microscrew print head is aligned based on the uppermost threaded segment of the threaded stem portion of the microscrew.

50. The system according to any one of claims 35 to 49, wherein the one or more rotary motors comprises a plurality of rotary motors, each of which is configured to control the rotational speed of each of the plurality of microscrews of the plurality of microscrew print heads.

51. The system according to any one of claims 35 to 50, wherein the one or more rotary motors comprises a single rotary motor configured to simultaneously control the rotational speed of the microscrews of the plurality of microscrew print heads.

52. The system according to any one of claims 35 to 51, wherein the actuator includes a pneumatic actuator, a mechanical actuator, an electromagnetic actuator, a hydraulic actuator, or an electric motor.

53. The system according to any one of claims 35 to 52, wherein the one or more actuators comprises a plurality of electric motors, each of which is configured to control the speed and acceleration of the vertical movement of each microscrew and / or the travel displacement of each microscrew.

54. The system according to claim 53, wherein the one or more electric motors comprises a single electric motor configured to simultaneously control the vertical speed and acceleration of the plurality of microscrews and the travel displacement of the plurality of microscrews via a push plate mechanism.

55. The system according to claim 54, wherein the push plate mechanism includes a sliding plate, a push plate, and a cam mechanism.

56. The system according to claim 55, wherein the cam mechanism is configured to convert the horizontal movement of the sliding plate into the vertical movement of the push plate.

57. The system according to any one of claims 35 to 56, wherein the drive module is configured to independently control one or more actuators and one or more rotary motors.

58. The system according to any one of claims 35 to 57, wherein the drive module provides combined control of the one or more actuators and the one or more rotary motors.

59. The system according to any one of claims 35 to 58, wherein at least one of the one or more rotary motors and the one or more actuators is a stepping motor.

60. The system according to any one of claims 35 to 59, further comprising a cross connector or cardan shaft used for coupling.

61. The system according to any one of claims 35 to 60, wherein the flow distribution module comprises a base plate, and the flow distribution plate and the plurality of microscrew print heads are arranged within the base plate.

62. The flow rate distribution plate comprises an upper plate and a lower plate, according to claim 61.

63. The system according to claim 61, wherein the base plate and the sleeves of the plurality of microscrew print heads are integrated.

64. The system according to any one of claims 35 to 63, further comprising a temperature control system outside the flow distribution plate, wherein the temperature control system comprises a heating device and a cooling device.

65. The system according to any one of claims 35 to 64, wherein the inlet of the flow rate distribution plate is equipped with a sealing mechanism.

66. The system according to any one of claims 35 to 65, wherein the entrance of the microscrew print head is equipped with a sealing mechanism.

67. The system according to claim 66, wherein the sealing mechanism is a sealing ring.

68. The system according to any one of claims 35 to 67, wherein the plurality of microscrew print heads are arranged in a natural equilibrium layout or a rheological equilibrium layout.

69. The system according to any one of claims 35 to 68, wherein the flow distribution plate is configured to divide the single flow into four or eight flows.

70. The system according to claim 69, wherein the flow distribution plate is configured to divide the single flow into 16 or 32 flows via one or more 1:4 or 1:8 subplates.

71. The system according to any one of claims 35 to 70, wherein the flow distribution plate is configured to divide the single flow into three, five, or seven flows via a rheological equilibrium layout.

72. The system according to any one of claims 35 to 71, further comprising a printing platform and a controller, the controller for moving the printing platform based on a Cartesian coordinate system, a polar coordinate system, or a cylindrical coordinate system.

73. A method of additive manufacturing via multiple microscrew print heads, Each of the above-mentioned microscrew print heads is Microscrew and Nozzle and Equipped with, The aforementioned microscrew is The threaded stem part, The conical head portion, The central portion between the threaded stem portion and the conical head portion Equipped with, The diameter of the central portion is smaller than that of the threaded stem portion, and the diameter of the central portion is larger than the maximum parameter of the conical head portion, and the threaded stem portion is provided with grooves for material transmission and volume measurement. The distal end of the nozzle is The inner surface of the cone, An outlet port for ejecting the aforementioned printing material and Equipped with, The aforementioned method, The printing material is melted using heating, and the printing material is pressurized. Distributing the single flow of the molten and pressurized printing material into multiple flows via a flow distribution plate, To cause each of the aforementioned multiple flows to reach the microscrew head among the aforementioned multiple microscrew print heads, In each microscrew print head, By raising the microscrew, the outlet port of the nozzle is opened, The process involves rotating the microscrew to introduce the respective flows into the grooves of the threaded stem portion of the microscrew, wherein the molten and pressurized printing material is configured to flow toward the distal end of the nozzle. The conical inner surface of the nozzle contacts the conical head portion of the microscrew, thereby closing the outlet port and lowering the microscrew to stop the ejection of the printing material from the nozzle. Methods that include...

74. The method according to claim 73, wherein an electric motor is configured to simultaneously control the vertical speed and acceleration of the plurality of microscrews and the travel displacement of the plurality of microscrews via a push plate mechanism.

75. The method according to any one of claims 73 to 74, wherein each of the multiple electric motors is configured to control the speed and acceleration of the vertical movement of each microscrew and the travel displacement of each microscrew.

76. The method according to any one of claims 73 to 75, wherein each of the multiple rotary motors is configured to control the rotational speed of its respective microscrew via a motor adapter shaft.

77. The system according to any one of claims 73 to 76, wherein a single rotary motor is configured to simultaneously control the rotational speed of the microscrews of the plurality of microscrew print heads via one or more gears and belts.

78. The method according to any one of claims 73 to 77, wherein the actuator and the rotary motor are configured to drive the combined movement of the microscrew.

79. The method according to any one of claims 73 to 78, further comprising closing the outlet port by lowering the microscrew while reducing the rotational speed of the microscrew.

80. Rotating the microscrew includes rotating the microscrew in a first direction. The method according to any one of claims 73 to 79, wherein the method includes removing a certain amount of the printing material from the distal end of the nozzle by lowering the microscrew and rotating the microscrew in the opposite direction to the first direction before closing the outlet port.

81. The method according to any one of claims 73 to 80, further comprising moving the printing platform and adjusting the amount of printing material discharged by the nozzle.

82. The method further includes heating the printing material according to a ladder scheme, The printing material is heated to a first temperature in the material supply module. The printing material is heated to a second temperature in the flow rate distribution model. The method according to any one of claims 73 to 81, wherein the printing material is heated to a third temperature in each nozzle.

83. The method according to claim 82, wherein the first temperature is 50°C, the second temperature is 70°C, and the third temperature is 105°C.

84. The method according to any one of claims 73 to 83, further comprising measuring the pressure of the printing material at the inlet of a microscrew print head or the flow distribution plate, and controlling the pressure of the printing material via a closed-loop control system.

85. The method according to any one of claims 73 to 84, wherein the printing material is a non-filamentary material, and the viscosity of the printing material when extruded by the nozzle is 800 Pa·s or more.

86. The method according to any one of claims 73 to 85, wherein the plurality of microscrew printing heads are configured to manufacture pharmaceutical dosage units.

87. A system for additive manufacturing, The system comprises a first printing station and a second printing station. The first printing station is, A first material supply module for melting and pressurizing a first printing material, wherein the first material supply module is equipped with a heater for melting the first printing material, A first flow distribution module that evenly divides a single flow of the molten and pressurized first printing material into a first plurality of flows, A first printing module comprising a set of needle valve print heads configured to discharge the first plurality of flows, Equipped with, The second printing station is, A second material supply module for melting and pressurizing a second printing material, wherein the second material supply module includes a heater for melting the second printing material, A second flow distribution module that evenly divides the single flow of the molten and pressurized second printing material into a second plurality of flows, A second printing module comprising a set of multiple microscrew print heads configured to discharge the second set of flows, Equipped with, Each of the aforementioned plurality of microscrew print heads is equipped with a microscrew, The aforementioned microscrew is The threaded stem part, The conical head portion, The central portion between the threaded stem portion and the conical head portion Equipped with, A system wherein the diameter of the central portion is smaller than that of the threaded stem portion, and the diameter of the central portion is larger than the maximum parameter of the conical head portion, and the threaded stem portion is provided with grooves for material transmission and volume measurement.

88. The system according to claim 87, wherein each of the first and second printing modules is configured to be extendable to accommodate a different number of print heads.

89. The system according to any one of claims 87 to 88, wherein each of the first printing station and the second printing station is configured to be extendable to accommodate different types of printing modules.

90. The system according to any one of claims 87 to 89, further comprising a set of droplet-ejection printheads, a set of injection printheads, a set of inkjet printheads, or any combination thereof.

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