System and method for high resolution negative film 3D printer

Abstract

Methods and apparatus for fabricating solid three-dimensional objects from liquid polymerizable material at high resolution. Material (202) is non-digitally coated on a film (204), excess material is digitally removed by a laser, leaving a negative of the layer to be printed, and then the image is joined with existing portions of the object (220) being fabricated and exposed to a non-digital UV curing light source. Since the only portion that is digitized is the material removal, and this portion is done by a laser, the printing speed and robustness of the fabrication process are significantly improved compared to conventional additive or 3D fabrication techniques.

Description

[0001] Related applications

[0002] This application claims priority to U.S. Provisional Application No. 62 / 704,446, filed May 11, 2020. Technical Field

[0003] The present invention relates to a method and apparatus for manufacturing solid three-dimensional objects from liquid polymerizable materials at high resolution. Background Technology

[0004] In conventional additive or 3D manufacturing techniques, the construction of 3D objects is performed layer by layer. Layer formation is achieved by curing photocurable resins under visible or UV light irradiation. Two techniques are known: one in which a new layer is formed on the top surface of the grown object; and the other in which a new layer is formed on the bottom surface of the grown object.

[0005] If a new layer forms on the top surface of the grown object, then after each irradiation step, the object under construction is lowered into a resin “pool,” a new resin layer is applied on top, and a new irradiation step is performed. An example of this technique is given in Hull’s U.S. Patent No. 5,236,637. A disadvantage of this type of “top-down” technique is the need to immerse the grown object in a deep pool of liquid resin and to reconstruct a precise overlay of the liquid resin before the next layer of the object is formed.

[0006] If the new layer forms at the bottom of the growing object, then after each irradiation step, the object in the construction must be separated from the base plate in the manufacturing well. An example of this technique is given in Hull’s U.S. Patent No. 5,236,637. While such “top-down” techniques may eliminate the need for deep wells to which the object is immersed by alternatively lifting the object from a relatively shallow well or pool, the problem with commercially implemented “top-down” manufacturing techniques like these is that extra care must be taken and additional mechanical elements employed when separating them due to the physical and chemical interactions between the consolidated layer and the base plate. For example, in U.S. Patent No. 7,438,846, an elastic separation layer is used to achieve “non-destructive” separation of the consolidated material at the bottom construction plane. Other methods employ sliding build plates, for example, as shown in U.S. Patent No. 9,636,873. Such methods introduce mechanical steps that may complicate the apparatus, slow down the process, and / or deform the product.

[0007] A sequential method for producing three-dimensional objects is described in considerable detail in U.S. Patent No. 7,892,474 regarding a “top-down” technique, and the best method to date is provided by WO 2014 / 126837. There, an interface is formed between first and second layers or regions of the same polymerizable liquid. The first layer or region (sometimes referred to as a “dead zone”) contains polymerization inhibitors (at least in a polymerization-inhibiting amount); in the second layer or region, the inhibitors have been consumed (or not otherwise incorporated or permeated therein) to the extent that polymerization is no longer substantially inhibited. The first and second regions do not form a strict interface with each other, but rather a compositional gradient exists, which can also be described as the formation of intermediate phases between them, rather than a sharp interface, because these phases are miscible with each other and also generate (partially or completely overlapping) polymerization gradients between them (and between the manufactured three-dimensional object and the build surface through which the polymerizable liquid is irradiated).

[0008] Despite its promising prospects, this technology has several limitations. First, it can only be used for one material formulation at a time, which greatly limits the physical properties of the articles produced by this technology. Second, the production rate is limited by the inhibitors used, the viscosity of the liquid phase, and the power of the UV light source. Additionally, the articles remain immersed in the resin bath and need to be cleaned at the end of the process to remove residues. Summary of the Invention

[0009] In view of the aforementioned limitations of current additive or three-dimensional (“3D”) manufacturing technologies, the present invention provides a faster method for producing three-dimensional articles by generating the next layer of the article under manufacture on a film at high resolution and exposing the film to a corresponding light source during contact with the previously formed article portion to produce the next layer of the formed article. Because this is a continuous sequential production process, the rate of object formation and its flexibility are improved compared to other technologies. Multiple materials can be introduced into each layer, and no cleaning is required at the end of the production process.

[0010] In one embodiment, a novel method for 3D printing is provided that reduces waste and increases manufacturing speed. Material is non-digitally coated onto a film, excess material is digitally removed by laser, and the complete image is then joined with an existing portion of the object being manufactured (also referred to herein as a sample) and exposed to a non-digital UV curing light source. Since the only part that is digitized is material removal, and this removal is done by laser, the printing speed and robustness of the manufacturing process are significantly improved compared to conventional additive or 3D manufacturing techniques.

[0011] Among the materials, high-viscosity materials are best suited for this method, as they do not move between the material spraying unit and the sample building unit. However, any material can be used, taking into account that the final resolution of the sample being produced will decrease as the material viscosity decreases.

[0012] One embodiment of the negative film 3D printing system configured according to the present invention includes: a film and roller-based coating system; a laser jetting system located on top of a material reuse unit; and a sample construction unit, wherein the film contacts the sample during UV curing. Another optional unit is a sample release unit, which can be operated using mechanical, chemical, or optical (e.g., laser) devices or any combination of these methods.

[0013] The coating system can be implemented in any of several ways. For example, in one embodiment, the coating system may include an syringe with a film-forming unit in which the coating film passes between two rollers. Other coating methods that can be used include conventional screen printing, dispenser unit printing, microgravure coating, slot die coating, inkjet printing, or roller coating.

[0014] The coating can be performed in a controlled environment, for example, to prevent solvent evaporation or oxidation and to minimize material waste for later reuse, and in some embodiments, the material coated on the membrane is carried out in a closed loop through a reuse unit, in which a small amount of material is added to the previously unused portion in each cycle.

[0015] In some cases, coating systems can support 3D printing of a variety of materials.

[0016] A negative digital laser jetting system can include a pulsed laser with sufficient energy to jet a negative image of material from a film surface. Possible lasers that can be used for this purpose include infrared (IR) lasers, ultraviolet (UV) lasers, carbon dioxide (CO2) lasers, etc.

[0017] The film used for transfer printing should be a transparent film, at least transparent (or nearly transparent) to the wavelength of the laser used, with or without a coating. Examples of transparent films that can be used are polyethylene terephthalate (PET), biaxially oriented polypropylene (BOPP), polyimide (PI), etc.

[0018] Film coatings are used to enhance the spraying of materials from film to material recycling systems. For this purpose, metal or other polymer coatings with additives can be used, which absorb at laser wavelengths and digitally generate transparent areas by exposure to a laser negative spraying system.

[0019] As mentioned above, the combination of materials that can be used for 3D printing in this system is very broad, and it is impractical to list all possible materials. By way of example, possible materials can be UV / visible light curable material formulations with UV-curable monomers and polymers, adhesives or sensitive materials, acrylates, epoxy resins, urethanes, adhesives, pastes, etc., and UV-curable monomers and polymers with additives (such as ceramics, metals, organic additives, fiber reinforcement materials, etc.), or UV-curable waxes.

[0020] This system can be used for low- or high-viscosity materials that are cured by light or partially, and also for materials that are cured by heat, such as ceramic and metal pastes, solder pastes (epoxy-based or urethane-based), or silicone family materials with or without UV-curable ends. The reaction can be carried out by light, heat, or other catalysts (Pt, OH, etc.) or a combination of these mechanisms.

[0021] This system can also be used for 3D printing highly sensitive materials, such as biocompatible materials. It can also be used for 3D printing thermoplastic materials at room temperature or high temperatures (with some adjustments).

[0022] The curing system used in the embodiments of this system is not a digital process, and therefore, curing apparatuses of varying degrees of complexity can be employed. For example, UV or visible light curing systems can be used, as well as IR or other thermal curing systems (as post-treatment). Chemical latent catalysts can also be used for the curing reaction.

[0023] As an example, basic UV formulations can use monomers and polymers such as acrylates, epoxy resins, urethanes, and other UV or photosensitive materials with photoinitiators and / or co-initiators or sensitizers, such as acetophenone, thioxanone, phosphine oxide, iodonium, and sulfonium salts.

[0024] The configuration of the sample release system can depend on the chemical properties of the membrane, may involve some laser ablation or cleaning of the top surface after curing, and / or may be a mechanical system. Any of several methods can be used, for example, a system that provides low-angle release toward the Y-axis (e.g., by moving the membrane away from the sample at a small angle), or a system that provides two Z-axis systems, one for the frame (holding the membrane) and one for the sample, or a system that provides acoustic vibration to release the membrane from the sample.

[0025] These and other embodiments of the present invention are described in detail below. Attached Figure Description

[0026] The invention is illustrated by way of example rather than limitation in the accompanying drawings, in which:

[0027] Figure 1Embodiments of the invention are illustrated in summary form, which include coating a film with material, removing excess material into a recycling system, and then exposing the coated film to a non-digital curing system (UV- or thermal-based) during contact with a sample, thereby reducing waste and eliminating the need for support material.

[0028] Figure 2 The system is schematically illustrated according to an embodiment of the invention, highlighting the coating process, negative printing using a material recovery unit, and curing during contact with the sample; an optional sample release unit is also shown.

[0029] Figures 3a to 3m This illustrates aspects of a process according to an embodiment of the present invention, which includes materials ( Figures 3a to 3c Negative film spraying and optional initial curing ( Figure 3d ), sample contact ( Figures 3e to 3f ), curing ( Figure 3g ), release process ( Figures 3h to 3j ), Sample surface cleaning ( Figure 3k ), and overall results and structure ( Figures 31 to 3m ).

[0030] Figure 4 An example of a system configured according to the invention is shown, the system having a spool and rollers for coating material onto a film and moving the film toward a sample contact point via a laser jetting unit during exposure to UV light for curing.

[0031] Figure 5 Show Figure 4 Another example of the system shown has several layers printed.

[0032] Figure 6 Show Figure 4 Another example of the system shown is in which several layers have been printed with optional support material added between the layers.

[0033] Figure 7 Show Figure 4 Another example of the system shown is in which several layers have been printed and a support addition system configured for spraying support material has been included.

[0034] Figure 8a and Figure 8b The illustrations depict various aspects of embodiments of the invention, wherein prior to contact with the sample ( Figure 8a ) and afterwards ( Figure 8b A variety of materials are used during the printing process.

[0035] Figure 9a and Figure 9bThis illustrates various aspects of embodiments of the invention, wherein printing uses an anti-adhesion foil to prevent adhesion during curing ( Figure 9a ) and sample release ( Figure 9b Sample deformation during the process.

[0036] Figure 10 Various aspects of embodiments of the invention are illustrated, wherein printing includes the use of a mechanical release system to achieve rapid and accurate sample construction.

[0037] Figure 11 Various aspects of embodiments of the invention are illustrated, wherein printing includes the use of a material recycling system to reduce waste of excess material during sample construction. Detailed Implementation

[0038] This invention relates to a method and apparatus for manufacturing solid 3D objects from liquid polymerizable materials at high resolution. In one embodiment, the system configured according to the invention employs a polymerizable liquid to jet a negative image of an initial coated film with a high-resolution laser, and exposes the image to a corresponding light source during film contact with a sample to produce the next layer of the sample. Because this is a continuous sequential production process, the rate of 3D object formation and its versatility are improved compared to conventional 3D printing processes. However, an overview is helpful before describing the invention in detail. Figure 1 This overview illustrates several components of a system 100 configured according to the invention: coating a film 10 with material, removing excess material into a recycling system 12, and exposing the coated film to a non-digital curing system (UV- or thermal-based) during contact with a sample 14.

[0039] By using negative images of the desired image, several key features of the invention are revealed: First, any excess material derived from the coating process can be reused without significant waste during sample construction. Second, the need for support material is eliminated (although its use remains an option, as discussed below). During curing and contact, the negative image is supported from its top side by the film, thus eliminating the need for support material in most cases. Some structures may require or benefit from additional support, and the invention accommodates such options. Third, the system configured according to the invention has the capability to print at very high rates because jetting and building occur in two distinct areas and these processes can be performed simultaneously. The primary constraint on printing speed is the curing process or negative printing time, but the times of these individual processes are not cumulative, meaning the overall printing speed is not limited by the cumulative combination of curing and negative printing times. There are also fewer limitations on the UV light source used for curing compared to conventional 3D printing processes, as the curing process is not digital.

[0040] The negative printing unit can be a laser-assisted deposition / laser dispensing system with a pulsed laser having sufficient energy to spray a negative image of the material from the film surface onto the recovery unit. The laser can be UV, IR, CO2, or any other laser.

[0041] If the printing unit is a laser-assisted deposition / laser dispensing system, then a uniformly coated substrate plays a crucial role in the system's robustness. Therefore, an additional coating system is added before the printing unit. This coating system can be a conventional coating system, such as a coating system based on microgravure printing or a slot die coater, or a roller coating system. It can also be a coating system based on screen printing, a dispenser, or an inkjet system. In one embodiment of the invention, the coating system can be based on, for example... Figure 4 The syringe and gap system are shown. In this system 400, material 402 is dispensed from syringe 404 (e.g., by an air or mechanical pump driving the material from the syringe onto the substrate) onto substrate 406 and coated substrate 408 is directed toward and moved (e.g., by a motor-driven roller or other actuator) through a clearly defined gap 410. The gap can be formed by, for example, Figure 4 The blade or other type of barrier shown is defined, or is defined by two closely spaced cylinders (e.g., rollers).

[0042] After passing through gap 410, a uniform material layer 412 is formed on the substrate, and the laser-assisted deposition / laser dispensing system 414 can spray material from the coated substrate into a material recovery system. From the laser-assisted deposition / laser dispensing system 414, the coated substrate 416 is conveyed to the curing station 418, where it comes into contact with the receiving substrate 420 in the presence of UV light and / or heat, thereby curing the material to form a new layer for the article being manufactured.

[0043] In other embodiments of the invention, the coating system may include a screen printing module, wherein a printing substrate is coated onto a screen or stencil having clearly defined apertures, and material is transferred onto the substrate using a blade or squeegee in a soft or hard bond manner. Alternatively, the coating system may include a dispenser or inkjet head to print material onto a carrier substrate. Alternatively, the coating system may be a gravure or microgravure printing system for coating a substrate with a highly uniform layer of material. In a further embodiment of the invention, the coating system may be a stencil system for coating a substrate with a highly uniform layer of material. Alternatively, the coating system may be a roller coating system for coating a substrate with a highly uniform layer of material.

[0044] In any of these and / or other embodiments of the invention, the coating system may be disposed within a closed unit with a controlled environment (temperature, pressure, etc.) to prevent solvent from evaporating from the printing material or to prevent the material from oxidizing, thereby helping to extend the shelf life of the material.

[0045] In some embodiments of the invention, the coating system comprises more than one material. This results in the controlled sequence of printing multiple materials onto an intermediate substrate (e.g., such as...). Figure 4 This allows for the possibility of printing more than one material onto the final substrate (e.g., the film on substrate 406), thereby making it possible to print more than one material onto the final substrate (e.g., Figure 4 On the receiving substrate 420 in the middle.

[0046] In one embodiment of the invention, the intermediate substrate of the coating system can be translated back and forth in a controlled manner (from the angle at which material is applied to the intermediate substrate) while opening the gap between the coater rollers, thereby creating the possibility of recoating the same area of ​​the intermediate substrate multiple times with printing material without contaminating the rollers. This process also reduces (or eliminates) the amount of intermediate substrate consumed during the initial printing process, thus preventing waste.

[0047] In some embodiments, after the current uniform material layer coated on the intermediate substrate has been consumed (in whole or in part) by printing in the printing unit, the intermediate substrate can be recycled back to the coating system for recoating or transferred back to the coating system for the application of a new uniform coating layer in the next printing process.

[0048] The film (or other intermediate substrate) used for printing can be a substrate with or without a metal (or other) coating that is transparent at the laser wavelength. Examples of such films (substrates) are PET, BOPP, PI, etc. The film may be coated with a metal or polymer coating having additives that adsorb at the laser wavelength and digitally produce transparent areas when exposed to a laser negative printing system.

[0049] Materials that can be used for printing in the system configured according to the invention include any liquid or paste material. However, the advantage of the existing system lies primarily in its ability to handle highly viscous materials that cannot be properly printed at high resolution by other methods. For example, the system configured according to the invention can be used to print UV / visible light curable material formulations and UV-curable monomers and polymers of adhesives or sensitive materials. Other materials that can be printed using the system configured according to the invention are acrylates, epoxy resins, urethanes, adhesives, pastes, and inks that are UV-curable or thermally curable. Further materials that can be printed using the system configured according to the invention are UV-curable monomers and polymers with additives (such as ceramics, metals, organic additives, fiber reinforcements, etc.). In addition, materials such as UV-curable waxes, low-viscosity or high-viscosity materials that are light-cured or partially cured, epoxy-based, urethane-based, or silicone-based materials with or without UV-curable ends, ceramic and metal pastes, as well as solder pastes, biocompatible materials, and thermoplastic materials (at room temperature or at high temperatures regulated by ambient temperature) can all be printed using the system configured according to the invention. Possible basic formulations and mechanisms can utilize monomers and polymers of acrylates, epoxy resins, and urethanes, or other UV or photosensitive materials with photoinitiators and / or co-initiators or sensitizers, such as acetophenone, thioxanone, phosphine oxide, iodonium, and sulfonium salts.

[0050] Figure 2 A system 200 configured according to an embodiment of the invention is shown. In this system, material 202 is first dispensed onto a transparent substrate 204 via a coating system 206 (e.g., a coating system using a syringe and a gap system, as discussed above). The material-coated substrate 208 is provided to a negative printing unit 210, in which a negative image of the layer to be added to the sample is generated by removing excess material (i.e., the portion of the coating material that will not be added to the sample) from the coated substrate (e.g., by laser jetting). As shown, this excess material can be collected by a material recycling system 212 and provided back to the coating system 206 for reuse. As shown in this view, any remaining material 214 on the coated substrate is provided to a curing system (e.g., a UV curing system) 216 and / or an imaging system en route to a sample construction unit 218, where UV curing and / or drying can be used during contact with a sample 220. By curing / drying the material upon contact with the sample (i.e., the previously formed portion of the article in manufacture, which is disposed on the receiving substrate 222), the next layer of the sample is printed directly onto it. The sample release system 224 then releases the sample 220 from the delivery substrate 204.

[0051] Figures 3a to 3mThis document details each step involved in the overall printing process. First, refer to... Figure 3a The diagram illustrates a negative spitting process 300. A material layer 302 is coated onto an intermediate substrate (e.g., a film or foil) 304. A laser 306 is used to spit a negative of the image (to be printed onto the next layer of the sample) from the coated substrate, utilizing the laser absorption properties of the material or coated metal film. The spitted material 308 is collected 310 in a material recycling unit 312 (or multiple units, if several materials are being used), and the material can be reused later. Figure 3a and Figure 3b Only fragments of image material 314 remain on membrane 304 for further use. Figure 3c ).

[0052] Optional, such as Figure 3d As shown, the image material 314 on the membrane can be exposed to low-power UV light 326 or temperature before contacting the sample. This is because some materials (primarily liquids) require enhanced clarity of image material boundaries before such contact; for example, to avoid significant reduction in print resolution, this process allows for clearly defined boundaries of portions of the material image 314. In this process, the UV partial curing station 318 may include a gas diffusion system 320 for introducing an inert gas (e.g., Ar, CO2, He, Ne, etc.) 322 into the workspace 324, where UV light 326 from a UV light source 316 will be incident on the material layer 314. The inert gas flows in from one or more gas inlets 328 and out through a diffuser 330 toward the workspace 324. A gas pressure homogenizer can be used to ensure a constant pressure throughout the system.

[0053] Preferably, the intermediate substrate 304 is coated with a thin metal foil 332, for example, a 20 nm thick Ti layer. The metal foil layer will significantly reduce the transmission of the present UV light 326, ensuring that only the edges of the material layer 314 near the area in contact with the intermediate substrate 304 are cured or partially cured. As an example, the 20 nm thick Ti layer will transmit only about one-tenth of the UV light 326 that would be transmitted to the unprotected areas of the intermediate substrate 304. In areas where the metal foil has been removed (e.g., by laser ablation or other processes), the UV light 326 will be incident on the edges of the fragments of the material layer 314, again ensuring that only these edges are cured or partially cured. As an additional safety device to prevent unwanted curing or over-curing of the fragments of the material layer 314, the gas diffusion system 320 may be made of a non-reflective material so that the UV light 326 is not reflected toward the fragments of the material layer 314.

[0054] The presence of inert gas 322 pumped through the diffuser removes any oxygen from the working space 324. The thickness of this working space region is related to the gas pressure as it is forced through the diffuser 330. With fragments of material layer 314 held in the oxygen-removed region of the working space, the UV curing system then cures the bottoms and edges of these fragments by exposing them to UV light 326 from a UV light source 316.

[0055] Figure 3e and Figure 3f Provides views before and after contact between membrane 304 (i.e., a segment of the coating material 314 on the membrane) and the sample, while Figure 3g The UV exposure and construction of the sample are illustrated. This stage can use UV exposure or high-temperature irradiation (in which case a coated polyimide film, such as Kapton, can be used) to achieve the transfer of material to the sample. As shown, film 304 is brought into the area where receiving substrate 334 is present, and the receiving substrate (or an existing layer of the sample, if present) is brought into contact with a fragment of coating material 314 on the film (e.g., by raising the state on which the receiving substrate is present). The fragment of coating material 314 is then cured by exposure to UV light 336 from UV light source 338. This can be the same as or different from the UV light source described above. Exposure to UV light 336 (and / or heat) cures the fragment of coating material to form a fragment of a new layer 340 of the sample (i.e., the object being manufactured).

[0056] After curing, the sample remains attached to the membrane 304 (through a segment of the newly cured layer 340). Therefore, a release mechanism is preferably provided. For this purpose, the laser itself (for negative printing) 306 can be used as the sample release unit, since the metallic coating of the membrane 304 is still beneath the now-cured material and can be used as... Figures 3h to 3j The laser wavelength absorption and sample release are shown. Laser 306 irradiates the location where fragments of the newly cured layer 340 exist, allowing this separation. The laser can also be used to remove metal residues 342 from the sample, which are released during sample release. Figure 3k It may have detached from membrane 304 during the process and is present in the sample. Figure 3l A clean cured layer 340 is left on the surface. The result 350 of printing several layers of 340 is shown. Figure 3m Presented in the middle.

[0057] Figures 4 to 7 An example of a system configuration for performing the method of the present invention is shown. In one embodiment of the invention, only one material is provided for printing only one layer. Figure 4 This configuration is illustrated: material 402 is coated onto membrane 406; laser system 414 removes the image negative, and multiple samples 420 move sequentially to contact membrane 406. Material 416 solidifies during contact, and a new sample replaces the old one.

[0058] Figure 5 Show Figure 4 The configuration shown is a 3D version. This time, the same sample 520 is repeatedly brought into contact with membrane 406, and new layers 522a, 522b, etc., are added (printed) to the sample each time. Curing occurs during contact between the top of the sample and the material in the new layer 524 on the membrane. However, it should be noted that if there is no direct contact between the material on the membrane and the sample, then transfer from the membrane to the sample will not occur. Therefore, transfer depends on the area of ​​each material unit on the membrane and the surface structure of the sample.

[0059] One way to overcome this problem is to add a support material 602 that will contact the membrane 406 and thus transfer all the material 524 on the membrane to the sample. Figure 6 The use of support material 602 is shown to collect all materials from the membrane into the sample.

[0060] Figure 7 The optional unit 702 is illustrated for use in 3D negative printing with a support material. The optional unit 702 mechanically (e.g., via syringe 706) injects the support material 704 to ensure a uniform sample height that will contact the film 406 during curing. The sample 520 moves back and forth between the curing location 710 and the support injection location 712 between the layers.

[0061] Even more advanced configurations of the systems configured according to embodiments of the present invention are systems for 3D printing of multiple materials. In such cases, several coating units are placed to provide different materials to the transfer film and coat the different materials onto the film or multiple films, remove the negative image of each corresponding material from the film, and then contact the material with the sample and transfer it therein. Figures 8a to 8b The diagram shows views before and after contact between a substrate 802 comprising the second material 804 and a sample 334 containing the first material 314. The negative images of the different materials are compatible, allowing them to coexist in the same layer.

[0062] The membrane itself can be a transparent anti-adhesion foil. For example, PTFE or PFE or other anti-adhesion foils can be used to ensure that the sample can be easily released from the membrane after curing. Figures 9a to 9b The diagram shows views before and after the release process based on the anti-adhesion properties of membrane 902. The method used for sample release can be a supplementary method to the aforementioned laser release mechanism or the sole release mechanism to be used.

[0063] Another method for sample release is likely the primary mechanical method. Figure 10A mechanical release system 1002 is shown, which can operate with or without the aforementioned release mechanism. Any of several mechanical methods can be used. For example, a low-angle release towards the "Y" axis can be used by moving the membrane 406 away from the sample 1004 at a small angle. Alternatively, two Z axes can be used, one for the frame (holding the membrane 406) and one for the sample 1004. Another method is to release the membrane 406 from the sample 1004 using acoustic vibration.

[0064] Figure 11 An additional feature of the system configured according to an embodiment of the invention is shown: a material reuse system 1102. To reduce waste, negative printing can be performed above a tray or other carrier on which unused material is collected and injected back into the coating unit via syringe 404.

[0065] One or more units controlling the operation of the various systems are not shown in the above views. Those skilled in the art will understand that such units, commonly referred to as controllers or similar names, are processor-based units programmable to perform the aforementioned processes by signaling elements of the coating system, negative printing unit, material reuse system, curing system, and sample release system. In some cases, these signals will actuate end effectors, rollers, lasers, UV or IR lighting / heating systems, and other components to perform the aforementioned tasks. Such controllers generally include one or more processors that execute computer-readable instructions (i.e., computer programs or routines) defined as described herein, which are instantiated and run on a non-transitory computer-readable medium. Such processes can be presented in any computer language and executed on any suitable programmable logic hardware. A processor-based controller on or together with which the methods of the present invention can be implemented typically includes: a bus or other communication mechanism for transmitting information; a main memory, such as RAM or other dynamic storage device, coupled to the bus, for storing information and instructions to be executed by the processor, and for storing temporary variables or other intermediate information during the execution of the instructions to be executed by the processor; and a ROM or other static storage device, coupled to the bus, for storing static information and instructions of the processor. Storage devices, such as hard disks or solid-state drives, may also be included and coupled to the bus for storing information and instructions. In some cases, the main controller may include a display coupled to the bus for displaying information to a user. In such cases, an input device including alphanumeric and / or other keys may also be coupled to the bus for passing information and command selection to the processor. Other types of user input devices, such as cursor control devices, may also be included and coupled to the bus for passing direction information and command selection to the processor and for controlling cursor movement on the display.

[0066] The controller may also include a communication interface coupled to the processor, which provides bidirectional wired and / or wireless data communication to and from the controller, for example, via a local area network (LAN). The communication interface sends and receives electrical, electromagnetic, or optical signals carrying streams of digital data representing various types of information. For example, the controller may network with a remote unit to provide data communication to a host computer or other user-operated devices. Therefore, the controller can exchange messages and data (including diagnostic information) with remote units to aid in fault diagnosis (if necessary).

[0067] Therefore, methods and apparatus for manufacturing solid three-dimensional objects from liquid polymerizable materials at high resolution have been described.

Claims

1. A system comprising: A coating system configured to coat a substrate with a uniform layer of liquid polymerizable material and provide the coated substrate to a negative printing unit, the negative printing unit configured to remove a portion of the liquid polymerizable material from the coated substrate and provide a final version of the coated substrate having remaining fragments of the liquid polymerizable material to a sample building unit, the sample building unit configured to bond the coated substrate having the remaining fragments of the liquid polymerizable material to a sample, and to cure the remaining fragments of the liquid polymerizable material with ultraviolet (UV) light when in contact with the sample, the remaining fragments of the liquid polymerizable material representing an image of a layer of an article being manufactured.

2. The system of claim 1, wherein the coating system comprises one of the following: A screen printing module configured to apply the liquid polymerizable material onto a screen or stencil having clearly defined openings using a blade or squeegee, and further transfer the liquid polymerizable material to the substrate in a soft or hard bonding manner. A dispenser configured to print the liquid polymerizable material onto the substrate; An inkjet head configured to print the liquid polymerizable material onto the substrate; A gravure printing or microgravure printing system configured to coat the substrate with the uniform layer of the liquid polymerizable material; A molding system configured to coat the substrate with the uniform layer of the liquid polymerizable material; A roller coating system configured to coat the substrate with a uniform layer of the liquid polymerizable material; and The syringe, pump, and actuator for the liquid polymerizable material, wherein the pump drives the liquid polymerizable material from the syringe onto the substrate, and the actuator is configured to convey the coated substrate toward and through a gap between rollers or cutters to produce a uniform layer of the liquid polymerizable material on the substrate with a thickness defined by the gap.

3. The system of claim 1, wherein the coating system is configured to coat the substrate with more than one liquid polymerizable material.

4. The system of claim 1, wherein the coating system includes a gap between rollers or cutters to produce a uniform layer of the liquid polymerizable material having a thickness defined by the gap, and is configured to bidirectionally translate the substrate through the coating system while adjusting the width of the gap.

5. The system of claim 1, wherein the negative printing unit is a laser-based system comprising a laser configured to remove the portion of the liquid polymerizable material by spraying the portion of the liquid polymerizable material from the coated substrate into a material recycling system.

6. The system of claim 1, wherein the substrate is one of the following: a continuous transparent film substrate, a transparent film substrate coated with a metal layer, or a transparent film substrate coated with a metal layer and a dielectric layer.

7. The system as described in any one of the preceding claims, further comprising: A support material adding unit is configured to inject support material onto the sample.

8. A method comprising: A coating system is used to coat a substrate with a material to produce a coated substrate having a uniform layer of liquid polymerizable material thereon. The coated substrate is transported to a negative printing unit and a portion of the liquid polymerizable material is removed there to leave an image of the layer of the article in the liquid polymerizable material retained on the substrate; After the portion of the liquid polymerizable material has been removed, the final version of the coated substrate is transported from the negative printing unit to the sample building unit; In the sample construction unit, the liquid polymerizable material retained on the substrate is bonded to the sample; as well as In the sample construction unit, when the liquid polymerizable material retained on the substrate comes into contact with the sample, the liquid polymerizable material retained on the substrate is cured with ultraviolet (UV) light.

9. The method of claim 8, wherein the uniform layer of the liquid polymerizable material on the substrate is generated by one of the following: A portion of the liquid polymerizable material is driven from the syringe onto the substrate using an air pump or a mechanical pump, and the substrate is translated toward and through a clearly defined gap between rollers or cutters, thereby producing the uniform layer of the liquid polymerizable material with a thickness defined by the gap; A screen printing module in which a screen or stencil with clearly defined holes is coated with the liquid polymerizable material and the liquid polymerizable material is transferred to the substrate in a soft or hard bonding manner using a blade or scraper; Distributor, inkjet head, gravure printing or microgravure printing system, wherein the substrate is coated with the uniform layer of the liquid polymerizable material; A molding system, wherein the molding system coats the substrate with the uniform layer of the liquid polymerizable material; and A roller coating system that coats the substrate with a uniform layer of the liquid polymerizable material.

10. The method of claim 8, wherein the coating system coats the substrate with more than one liquid polymerizable material.

11. The method of claim 8, wherein the coating system includes a gap between rollers or cutters to produce a uniform layer of the liquid polymerizable material having a thickness defined by the gap, and the method further includes, while adjusting the width of the gap, bidirectionally translating the substrate through the gap in a controlled manner.

12. The method of claim 8, wherein the negative printing unit is a laser-based system including a laser, wherein removing the portion of the liquid polymerizable material from the substrate comprises using the laser to spray the portion of the liquid polymerizable material from the substrate into a material recycling system.

13. The method of claim 8, wherein the substrate is one of: a continuous transparent film substrate, a transparent film substrate coated with a metal layer, or a transparent film substrate coated with a metal and a dielectric layer.

14. The method of claim 8, wherein the substrate is rolled to deliver an image printed at the negative printing unit to the sample building unit.

15. The method of any one of claims 8 to 14, further comprising: Support material is injected into the sample at the support material addition unit.

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