3D printing system for advanced silicone additive manufacturing

Abstract

Embodiments of the present disclosure provide three dimensional (3D) printing systems and related methods for advanced silicone additive manufacturing. One such system comprises a controller; a print head having a print needle, a syringe extruder configured regulate a flow of soft ink materials through the print needle, wherein the syringe extruder is controlled by a stepper motor; a positioner assembly configured to control a movement of print head in three dimensions, wherein the positioner assembly comprises three linear stages controlled by a plurality of stepper motors; and a multiaxis motor controller configured to receive a print command and direct the syringe extruder and the positioner assembly to perform the print command, wherein the multiaxis motor control is configured to send simultaneous commands to the stepper motor of the syringe extruder and the plurality of stepper motors of the positioner assembly.

Description

3D PRINTING SYSTEM FOR ADVANCED SILICONE ADDITIVE MANUFACTURINGCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to co-pending U.S. provisional application entitled, “3D Printing System for Advanced Silicone Additive Manufacturing,” having application number 63 / 511 ,051 , filed June 29, 2023, which is entirely incorporated herein by reference.TECHNICAL FIELD

[0002] The present disclosure is generally related to embedded three-dimensional object printing.BACKGROUND

[0003] Embedded three-dimensional (3D) object printing, such as that used to fabricate soft structures, involves the printing of soft ink filaments in a support medium made from jammed particulate systems. Fabrication of such complex structures often requires the print needle of a 3D printer to trace a precise, seamless trajectory while depositing viscous ink at a controllable flow rate. However, most conventional 3D printers cannot support the fabrication of such structures with the required complex print trajectory that is needed.SUMMARY

[0004] Embodiments of the present disclosure provide three dimensional (3D) printing systems and related methods for advanced silicone additive manufacturing. One such system comprises a controller configured to control operations of a 3Dprinter; a print head of the 3D printer having a print needle, wherein the print needle is configured to inject soft ink material in a spatial path within support material to form a 3D object; a syringe extruder of the 3D printer configured to use displacement control to regulate a flow of soft ink materials through the print needle, wherein the syringe extruder is controlled by a stepper motor; a positioner assembly of the 3D printer configured to control a movement of print head in three dimensions, wherein the positioner assembly comprises three linear stages controlled by a plurality of stepper motors; and / or a multi-axis motor controller configured to receive a print command from the controller and direct the syringe extruder and the positioner assembly to perform the print command, wherein the multi-axis motor control is configured to send simultaneous commands to the stepper motor of the syringe extruder and the plurality of stepper motors of the positioner assembly.

[0005] The present disclosure can also be viewed as a method for advanced silicone additive manufacturing. In this regard, one embodiment of such a method comprises providing a three-dimensional (3D) printing apparatus having a print needle for injecting soft ink material in a spatial path within support material to form a 3D object; a syringe extruder configured to use displacement control to regulate a flow of soft ink materials through the print needle, wherein the syringe extruder is controlled by a stepper motor; and a positioner assembly configured to control a movement of print head in three dimensions, wherein the positioner assembly comprises three linear stages controlled by a plurality of stepper motors; receiving, by a multi-axis motor controller, a print command; and / or directing, by the multi-axis motor controller, the syringe extruder and the positioner assembly to perform the print command by sending simultaneous commands to the stepper motor of the syringe extruder and the plurality of stepper motors of the positioner assembly.

[0006] The present disclosure also describes a non-transitory computer readable storage medium having instructions stored thereon that, in response to execution by a computer-based system, cause the computer-based system to perform operations comprising: receiving, by a multi-axis motor controller, a print command for a three- dimensional (3D) printing apparatus having a print needle for injecting soft ink material in a spatial path within support material to form a 3D object; a syringe extruder configured to use displacement control to regulate a flow of soft ink materials through the print needle, wherein the syringe extruder is controlled by a stepper motor; and a positioner assembly configured to control a movement of print head in three dimensions, wherein the positioner assembly comprises three linear stages controlled by a plurality of stepper motors; and / or directing, by the multi-axis motor controller, the syringe extruder and the positioner assembly to perform the print command by sending simultaneous commands to the stepper motor of the syringe extruder and the plurality of stepper motors of the positioner assembly.

[0007] In one or more aspects for such systems, methods, and / or devices, the performed operations further comprise cooling the soft ink material before injecting the soft ink material; injecting the soft ink material within the support material as the print head moves in three dimensions; and / or curing the soft ink material that has been injected within the support material.

[0008] In one or more aspects for such systems, methods, and / or devices, the print head moves in synchronization with movement of the positioner assembly; an extrusion flow rate is based on displacement control of the positioner assembly without a feedback system being deployed; the soft ink material is a silicone-based material; and / or the printing apparatus further has a syringe unit configured to hold the soft ink material.

[0009] In one or more aspects, such systems, methods, and / or devices further involve a syringe unit configured to hold the soft ink material, wherein a tube carries the soft ink material from the syringe unit to the print head; a cooler component or system configured to cool the soft ink material inside the syringe unit; and / or a support container configured to hold the support material.

[0010] Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

[0012] FIG. 1 is a block diagram of a three-dimensional printer system in accordance with an embodiment of the present disclosure.

[0013] FIG. 2 shows a printing apparatus for three-dimensionally printing in accordance with embodiments of the present disclosure.DETAILED DESCRIPTION

[0014] Embodiments of the present disclosure provide 3D printing systems and related methods for advanced silicone additive manufacturing. In embedded 3D object printing, soft ink materials (e.g., silicone ink materials) are printed onto a support material within a support bath, where the soft ink material transitions from a fluid material to a solid or semi-solid state after deposition in the support material order to fabricate 2D or 3D structures, which may be difficult using conventional 3D printers.

[0015] Objects made using silicone additive manufacturing, such as those made using silicone elastomer, enjoy a wide range of applications in biomedical diagnostics, therapeutics, as well as consumer electronics. Silicone elastomer enables properties such as low elastic modulus, high extensibility and toughness, excellent thermal and oxidative stability, and chemical inertness. However, it is difficult or impractical to form many objects of silicone elastomer using conventional 3D printing techniques. Yet the potential value of high-performance 3D printing with silicone is clear, given the ubiquity of silicone-based components in advanced technologies, such as neurovascular, heart valve models, and hydrogels, and everyday consumer products.

[0016] Referring now to FIG. 1 , a block diagram of a 3D printer system 100 in accordance with an embodiment of the present disclosure is shown. The 3D printer system 100 includes a controller 105 and a printing apparatus 110. Controller 105 is configured to prepare digital data that characterizes a 3D object for printing, and control the operation of the printing apparatus 110. The controller 105 may include, for example, a processor 115, a memory unit 120, and print instructions or firmware 125.

[0017] Data and instructions maybe transferred between controller 105 and a CAD (computer-aided design) module (not shown), between controller 105 and printing apparatus 110, and / or between controller 105 and other system elements, such as amulti-axis motor controller 135, camera sensor(s) 140, cooling system 165 for the printing syringe 155, etc. Accordingly, controller 105 may be suitably coupled and / or connected to various components of printing apparatus 110.

[0018] Controller 105 may utilize object modeling data (OMD) 130 representing an object to be printed. Controller 105 may convert such data to instructions for the various units within 3D printer system 100 to print a 3D object. Controller 105 may be located inside printing apparatus 110 or outside of printing apparatus 110. Controller 105 may be located outside of printing system 100 and may communicate with printing system 100, for example, over a wire and / or using wireless communications. In some embodiments, controller 105 may include a CAD module / system or other suitable design system. In alternate embodiments, controller 105 may be partially external to 3D printer system 100. For example, an external control or processing unit (e.g., a personal computer, workstation, computing platform, or other processing device) may provide some or all of the printing system control capability.

[0019] In some embodiments, print instructions 125, a print file, or other collection of print data may be prepared and / or provided and / or programmed, for example, by the controller 105 or a computing platform connected to 3D printer system 100. The print instructions 125 may be used to determine, for example, the order and configuration of deposition of building material via, for example, movement of and activation and / or non-activation of one or more print needles 147 of print head 145, according to the 3D object to be built. In accordance with the present disclosure, the print instructions 125 may further be configured to determine a spatial path of a print needle 147 within a support material, where the support material (e.g., hydrogels) flows around the print needle while trapping deposited inks in space, providing stability to the printed structures. According to some embodiments, the print needle 147 mayinclude a fine hollow tip, which may carefully trace out spatial paths within the support material while injecting the soft ink material. In one embodiment, the print instructions comprise, but are not limited to, G-code toolpath instructions for the controller.

[0020] Thus, the support material for 3D printing may allow 3D printing of soft ink materials, such as silicone, to form a desired structure in three dimensions. For example, a computer-controlled print needle (injector tip) may trace out a spatial path within a support material and inject ink materials at locations along the path to form a desired 3D pattern or shape. In various embodiments, the 3D printer system 100 utilizes a support material that leverages ultra-low interfacial tension with the deposited silicone inks, enabling fabrication of structures that are 4 microns in thickness. Tracking of the print needle 147 may be enabled via one or more camera sensors 140 that are disposed to capture positioning of the print needle 147.

[0021] Printing apparatus 110 may include positioner assembly 150, syringe unit 155, syringe unit extruder(s) 158, print head(s) 145, print needle(s) 147, a support bath platform or container 160, and a cooling system 165 for the syringe unit, among other components. Positioner assembly 150 may control the movement of print head 145, such as by multiple linear stages controlled by stepper motors. Likewise, syringe unit extruder(s) 158 may control the flow of soft ink materials to and through the print needle 147, such as by a stepper motor. Accordingly, in various embodiments, the multiple stages and sensors of the system are synchronized and controlled through a single user-friendly API, which enables the design of required shapes and the control of the fabrication process.

[0022] After injection, the soft ink material may be transformed into a permanent solid-like phase having the printed 3D pattern or shape. In some embodiments, the soft ink material may be cured within the support material using, for example,ultraviolet (UV) illumination, to achieve a phase change. The printed object may be extracted after curing by removing the surrounding support material using any suitable means.

[0023] Soft ink materials may include any suitable kind of embedded print material, such as, silicone elastomer dispersions. Examples of suitable silicone elastomer dispersions may include dimethicone / vinyl dimethicone crosspolymer blends from Dow Coming Corporation (Midland, Mich.) under trade name Dow Corning® 9040 silicone elastomer (cyclopentasiloxane and dimethicone crosspolymer), DC-9041 (dimethicone and dimethicone crosspolymer), EL-9140DM (dimethicone and dimethicone crosspolymer); SFE 839, a cyclopentasiloxane (and) dimethicone / vinyl dimethicone crosspolymer from Momentive Performance Materials Inc. (Waterford, N.Y.); cyclopentasiloxane (and) cetearyl dimethicone / vinyl dimethicone crosspolymer from Momentive Performance Materials Inc. under the tradename Silsoft* Silicone Gel; KSG-15 (cyclopentasiloxane and dimethicone / vinyl dimethicone crosspolymer), KSG- 16 (dimethicone and dimethicone / vinyl dimethicone crosspolymer), KSG-18 (phenyl trimethicone and dimethicone / phenyl vinyl dimethicone crosspolymer), and KSG-41 (mineral oil and vinyl dimethicone / lauryl dimethicone crosspolymer) from Shin Etsu Silicones (Akron, Ohio).

[0024] Although printing of ink material using a print needle or injector tip is discussed, it should be understood that the materials and methods disclosed in the present application are not limited to any particular 3D printing techniques. According to some embodiments, a support material for 3D printing of silicone may be immiscible with silicone in the ink material. In some embodiments, it is desirable to reduce the interfacial tension between the support material and silicone to avoid instabilities due to breakup during printing.

[0025] Controller 105 may be implemented using any suitable combination of hardware and / or software. In some embodiments, controller 105 may include, for example, the processor 115, the memory unit 120, and software or operating instructions, such as print instructions 125. Processor 115 may include conventional devices, such as a Central Processing Unit (CPU), a microprocessor, a "computer on a chip", a micro controller, etc. Memory unit 120 may include conventional devices such as Random Access Memory (RAM), Read-Only Memory (ROM), or other storage devices, and may include mass storage, such as a CD-ROM, SD / Micro SD, USB storage devices, or a hard disk. Controller 105 may be included within, or may include, a computing device such as a personal computer, a desktop computer, a mobile computer, a laptop computer, a server computer, or workstation (and thus part or all of the functionality of controller 105 may be external to 3D printer system 100). Controller 105 may be of other configurations, and may include other suitable components.

[0026] FIG. 2 illustrates the printing apparatus 110 for three-dimensionally printing. The apparatus 110 may include a support container 160, a print needle 147, a syringe unit 155, and tubing 280. The support container 160 may hold a support material 220. The needle 147 may displace the support material 220 with a soft ink material 260. The tubing 280 may be connected to an output of the syringe 155 and an input of the needle 147. The syringe 155 may include the an amount of the soft ink material 260, which it may inject via the tubing 280 and the needle 147 into the support material 220. According to some embodiments, the support container 160 may be a tub, a bowl, a box, or any other suitable container for the soft ink material 260.

[0027] According to some embodiments, the apparatus 110 may further include a positioner assembly 150 having stepper motors enabling movement of the print head145 in three dimensions. Thus, the positioner 150 may cause relative displacement between the needle 147 and the soft ink material 220. For example, the positioner 150 may position the needle 147 three-dimensionally so that the support material 260 enters the soft ink material 220 at the desired locations. The positioner 150 may also be used in conjunction with the support container 160 to create specific shapes as the platform and positioner 150 each cause displacement simultaneously. For example, the support container 160 may cause relative rotation between the soft ink material 220 and the needle 147 while the positioner 150 may displace the needle 250 up and down, side to side, back and forth, and so on, creating any shape desired. Alternatively or additionally, the motion of the needle 147 may be synchronized with the movement of the positioner 150.

[0028] The syringe-based extruder 158 and the positioner 150 are driven by a drive mechanism (driver) of multi-axis motor controller 135. Using the positioner, the needle 147 can be moved in horizontal, forward / backward, and / or vertical directions. Accordingly, a structure can be printed in any direction in 3D space. In addition to printing in the XY plane, a structure can also be printed in a non-XY plane, such as the XZ plane, or a plane at any angle. A structure can also be printed in a non-planar fashion in a curved path, such as a helix.

[0029] In various embodiments, the drive mechanism for an individual stepper motor driver is a chip or integrated circuit that controls the power flow to the stepper motor so that the motor can be precisely positioned. The multi-axis controller 135 works in conjunction with the system controller 105 and switches from one drive function to another as necessary to command the positioner 150 and extruder 158 components.

[0030] Thus, as opposed to having multiple individual single-axis motor controllers that receive movement commands from the controller and generate and transmit separate signals to the stepper motor drivers, the multi-axis motor controller 135 can receive movement commands from the controller 105 and can generate signals for each of the stepper motors that specifies how much the stepper motor needs to move, including the stepper motor for the syringe-based extruder 158, and can coordinate and transmit the signals to the stepper motor to provide smooth operations.

[0031] Since conventional 3D printers often daisy chain three single axis controllers, a conventional controller has to carefully attempt to synchronize all three axes of motion to reach a target point at the same time. But, since each axis of motion can have an individual error, it is hard to produce a smooth path of motion for the print needle. This results in each of the positioner stepper motors (or XYZ stages) reaching a target position at slightly different times and producing an irregular path.

[0032] However, an exemplary 3D printer system of the present disclosure is made of precision linear stages programmed through a multi-axis motor controller 135 that can overcome these challenges. In accordance with the present disclosure, a single multidimensional or multi-axis motor controller 135 is provided to simultaneously send control or positioning signals to each positioner (XYZ stage) motor in addition to a control signal to the extruder stage which results in smooth motion and flow control.

[0033] Additionally, the stepper motors employed with extruders / feeders in conventional printers cannot accommodate the high pressure and accuracy required to extrude highly viscous fluids, such as silicone. A problem with trying to control the flow rate via a controlled pressure is that a material with a certain viscosity will change its flow rate when the viscosity of the material changes even if the pressure does not change, which happens with shear thinning or thickening materials where the viscositycan change as the material flows through from the syringe pump to the injection tip. Thus, in conventional additive manufacturing printing systems that attempt to control the flow rate using pressure, a feedback system is needed to monitor the change in flow rate so that it can adjust the pressure. However, with an exemplary additive manufacturing printing system of the present disclosure that utilizes displacement control to set the extrusion flow rate, a feedback system is not required. Accordingly, an exemplary system enables the flow of material out of the injection tip to occur at a controlled flow rate or speed while the positioner stages are moving at a controlled rate of motion.

[0034] An illustrative example of prototype of an exemplary 3D printer is described next. Accordingly, the prototype 3D printer uses a linear stage as a syringe pump (Physik Instrumente) mounted to three linear translations stages (Newport). Print needles are fabricated by pulling glass microcapillaries (e.g., 1 mm outer diameter) using a pipette puller (David Kopf Instruments). The pulled capillaries are secured to Luer-lock hubs. Additionally, metal needles (e.g., between 23G and 34G) are connected to the printing syringes, loaded with the silicone ink, and mounted to the syringe pump. Custom-written MATLAB scripts and functions are used to produce precise trajectory paths for the syringe pump and the translation stages, which trace the needle tip along the designed 3D structure within containers containing the support material.

[0035] Specifically, regarding the translation stages and motion control, the prototype system includes four linear stages; three for each axis of motion (e.g., Y&Z axes: ILS-200PP - 200mm travel distance, centered load capacity of 250N, origin repeatability of + / - 0.5 pm; max velocity 50mm / sec; max acceleration 250 mm / sec2; X axis: ILS-300PP - 300mm travel distance, centered load capacity of 600N, originrepeatability of + / - 0.65 pm; max velocity 50mm / sec; max acceleration 250 mm / sec2) and one for the extruder, programmed by a multi-axis motor controller and driver (e.g., Newport Model No. XPS-Q4 - 4-axis integrated motion controller / driver).

[0036] As discussed, the printing system uses displacement-controlled extrusion. The extrusion system in the prototype is a custom-built syringe pump, comprising a linear translation stage (M-403.2DG - DC gear motor with rotary encoder (2000 cts / rev); centered load capacity of 50N; 50mm travel distance; 0.2 pm accuracy; max velocity 2.5mm / sec) and syringe mounting hardware.

[0037] The prototype 3D printer system is equipped with an optical sensor or camera 140 (e.g., USB inspection camera; 2 MP resolution; 30 fps; IP67 water resistance) for precise needle detection and calibration for high-resolution fabrication and high repeatability during multi-material printing.

[0038] The prototype 3D printer system is equipped with a customized Peltierbased cooling system (e.g., Peltier module - TE-63-1 .0-2.5 modules with a temperature differential of 70 Celsius at 7.9 V and 1.9 Amp) for the printing syringe enabling longer print times by prolonging the work life for RTV (room-temperature- vulcanizing) silicone formulations.

[0039] The prototype 3D printer system is housed in a HEPA-filtered environmental chamber (e.g., Air Science PURAIR PCR-48; laminar flow cabinet with HEPA filters with UV decontamination) to maintain a clean room atmosphere, such as during the fabrication of biomedical devices.

[0040] Certain embodiments of the present disclosure can be implemented in hardware, software, firmware, or a combination thereof. In one embodiment, the print instructions 125 are implemented in software or firmware that is stored in a memory and that is executed by a suitable instruction execution system. Such software orfirmware can be stored in a computer readable medium, such as memory and be executed by a suitable instruction execution system. If implemented in hardware, as in an alternative embodiment, the print instructions can be implemented with any or a combination of the following technologies, which are all well known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon data signals, an application specific integrated circuit (ASIC) having appropriate combinational logic gates, a programmable gate array(s) (PGA), a field programmable gate array (FPGA), etc.

[0041] In the context of this document, a "computer-readable medium" can be any means that can contain, store, communicate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. The computer readable medium can be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device. More specific examples (a nonexhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM) (electronic), a read-only memory (ROM) (electronic), an erasable programmable readonly memory (EPROM or Flash memory) (electronic), an optical fiber (optical), and a portable compact disc read-only memory (CDROM) (optical).

[0042] It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the disclosure. Many variations and modifications may be made to the above-described embodiments without departing substantially from the spirit and principles of the disclosure. All such modifications andvariations are intended to be included herein within the scope of this disclosure and the following claims.

Claims

CLAIMSTherefore, at least the following is claimed:1 . A three-dimensional (3D) printing system comprising: a controller configured to control operations of a 3D printer; a print head of the 3D printer having a print needle, wherein the print needle is configured to inject soft ink material in a spatial path within support material to form a 3D object; a syringe extruder of the 3D printer configured to use displacement control to regulate a flow of soft ink materials through the print needle, wherein the syringe extruder is controlled by a stepper motor; a positioner assembly of the 3D printer configured to control a movement of print head in three dimensions, wherein the positioner assembly comprises three linear stages controlled by a plurality of stepper motors; and a multi-axis motor controller configured to receive a print command from the controller and direct the syringe extruder and the positioner assembly to perform the print command, wherein the multi-axis motor control is configured to send simultaneous commands to the stepper motor of the syringe extruder and the plurality of stepper motors of the positioner assembly.

2. The system of claim 1 , wherein the soft ink material is a silicone-based material.

3. The system of claim 1 , further comprising a syringe unit configured to hold the soft ink material, wherein a tube carries the soft ink material from the syringe unit to the print head.

4. The system of claim 3, further comprising a cooler component configured to cool the soft ink material inside the syringe unit.

5. The system of claim 1 , further comprising a support container configured to hold the support material.

6. The system of claim 1 , wherein the print head is configured to move in synchronization with movement of the positioner assembly.

7. The system of claim 1 , wherein an extrusion flow rate is based on displacement control of the positioner assembly without a feedback system being deployed.

8. A method comprising: providing a three-dimensional (3D) printing apparatus having a print needle for injecting soft ink material in a spatial path within support material to form a 3D object; a syringe extruder configured to use displacement control to regulate a flow of soft ink materials through the print needle, wherein the syringe extruder is controlled by a stepper motor; and a positioner assembly configured to control a movement of print head in three dimensions, wherein the positioner assembly comprises three linear stages controlled by a plurality of stepper motors;receiving, by a multi-axis motor controller, a print command; and directing, by the multi-axis motor controller, the syringe extruder and the positioner assembly to perform the print command by sending simultaneous commands to the stepper motor of the syringe extruder and the plurality of stepper motors of the positioner assembly.

9. The method of claim 8, wherein the soft ink material is a silicone-based material.

10. The method of claim 8, wherein the printing apparatus further has a syringe unit configured to hold the soft ink material, the method further comprising cooling, by a cooler system, the soft ink material inside the syringe unit.11 . The method of claim 8, further comprising injecting the soft ink material within the support material as the print head moves in three dimensions.

12. The method of claim 11 , further comprising curing the soft ink material that has been injected within the support material.

13. The method of claim 11 , wherein the print head moves in synchronization with movement of the positioner assembly.

14. The method of claim 11 , wherein an extrusion flow rate is based on displacement control of the positioner assembly without a feedback system being deployed.

15. A non-transitory, tangible computer readable storage medium having instructions stored thereon that, in response to execution by a computer-based system, cause the computer-based system to perform operations comprising: receiving, by a multi-axis motor controller, a print command for a three- dimensional (3D) printing apparatus having a print needle for injecting soft ink material in a spatial path within support material to form a 3D object; a syringe extruder configured to use displacement control to regulate a flow of soft ink materials through the print needle, wherein the syringe extruder is controlled by a stepper motor; and a positioner assembly configured to control a movement of print head in three dimensions, wherein the positioner assembly comprises three linear stages controlled by a plurality of stepper motors; and directing, by the multi-axis motor controller, the syringe extruder and the positioner assembly to perform the print command by sending simultaneous commands to the stepper motor of the syringe extruder and the plurality of stepper motors of the positioner assembly.

16. The non-transitory, tangible computer readable storage medium of claim 15, wherein the operations further comprise cooling the soft ink material before injecting the soft ink material.

17. The non-transitory, tangible computer readable storage medium of claim15, wherein the operations further comprise injecting the soft ink material within the support material as the print head moves in three dimensions.

18. The non-transitory, tangible computer readable storage medium of claim 17, wherein the operations further comprise curing the soft ink material that has been injected within the support material.

19. The non-transitory, tangible computer readable storage medium of claim 15, wherein the print head moves in synchronization with movement of the positioner assembly.

20. The non-transitory, tangible computer readable storage medium of claim15, wherein an extrusion flow rate is based on displacement control of the positioner assembly without a feedback system being deployed.

Images