System and method for a high-resolution negative 3D printer

Abstract

Systems and methods for fabricating solid three-dimensional objects from liquid polymerizable materials at high resolution are provided. The method involves applying material non-digitally onto a film, digitally removing excess material with a laser to leave a negative image of the layer to be printed, and then engaging that image with an existing portion of the object being fabricated and exposing it to a non-digital UV curing light source. Because the only part of the digitization is material removal, which is done with a laser, the speed of printing and the robustness of the manufacturing process are significantly improved over traditional additive or 3D fabrication techniques.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority to U.S. Provisional Patent Application No. 62 / 704,446, filed on May 11, 2020.

[0002] (Technical Field) The present invention relates to methods and apparatuses for fabricating solid three - dimensional objects from liquid polymerizable materials with high resolution.

Background Art

[0003] In conventional additive or three - dimensional manufacturing techniques, the shaping of three - dimensional objects is performed layer by layer. Layer formation is carried out by solidifying a photocurable resin under the action of visible light or UV light irradiation. Two techniques are known, one forms a new layer on the upper surface of the growing object, and the other forms a new layer on the lower surface of the growing object.

[0004] When forming a new layer on the upper surface of the growing object, after each irradiation step, the object being shaped is lowered into a resin "pool", a new resin layer is applied to the upper surface, and a new irradiation step is performed. An example of such a technique is presented in Hull's U.S. Patent No. 5,236,637. The disadvantage of such a "top - down" technique is that the growing object is submerged in a deep pool of liquid resin and it is necessary to reconstruct an accurate coating layer of the liquid resin before forming the next layer of the object.

[0005] When forming a new layer at the bottom of a growing object, it is necessary to separate the object being shaped from the bottom plate in the fabrication well after each irradiation step. An example of such a technique is presented in Hull's U.S. Patent No. 5,236,637. Such a "bottom-up" technique has the potential to eliminate the need for a deep well in which to submerge the object by instead lifting the object from a relatively shallow well or pool. However, when implemented commercially, the problem with such "bottom-up" fabrication techniques is that when separating the solidified layer from the bottom plate, due to the physical and chemical interactions between them, great care must be taken and additional mechanical elements must be employed. For example, in U.S. Patent No. 7,438,846, an elastic separation layer is used to achieve "non-destructive" separation of the solidified material at the bottom shaping surface. In other approaches, a sliding shaping plate is employed, as shown, for example, in U.S. Patent No. 9,636,873. Such approaches complicate the apparatus, make the method time-consuming, and / or introduce mechanical steps that can potentially distort the manufactured object.

[0006] A continuous process for manufacturing a three-dimensional object is proposed in considerable detail in U.S. Patent No. 7,892,474 with respect to "top-down" techniques, and the best method to date is provided by International Publication No. 2014 / 126837. Therein, an interface is formed between a first and a second layer or zone of the same polymerizable liquid. The first layer or zone (which may also be referred to as the "dead zone") contains a polymerization inhibitor (in at least an amount that suppresses polymerization), and in the second layer or zone, the inhibitor has been consumed (or otherwise not incorporated or penetrated) to the point where polymerization is no longer substantially suppressed. The first zone and the second zone do not form a sharp interface between each other, but rather, there is a compositional gradient that can also be regarded as the formation of an interphase between them, in contrast to a sharp interface. This is because the phases are miscible with each other and furthermore create a (partially or fully overlapping) polymerization gradient between them (and also between the three-dimensional object being fabricated and the shaping surface where the polymerizable liquid is irradiated).

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0008] Although desirable, this technique has several limitations. First, it can only be used for one material formulation at a time, and the physical properties of the articles that can be manufactured by this technique are greatly limited. Second, the manufacturing speed is limited by the inhibitor used, the viscosity of the liquid phase, and the UV light source output. Furthermore, the articles are still immersed in a resin bath and need to be washed at the end of the process to remove residues.

Means for Solving the Problems

[0009] Considering the above limitations of current additive or three-dimensional ("3D") manufacturing techniques, the present invention provides a much faster method for manufacturing three-dimensional articles by creating the next layer of the article being fabricated with high resolution on a film and exposing it to a corresponding light source during contact between the film and the previously formed portion of the article to manufacture the next layer of the formed article. Since this is a continuous sequence of manufacturing processes, the formation speed and versatility of the article are improved compared to other techniques. Multiple materials can be introduced in each layer, and no washing is required at the end of the manufacturing process.

[0010] In one embodiment, a new method of 3D printing is provided that reduces waste and improves manufacturing speed. The material is applied non-digitally onto a film, excess material is digitally removed with a laser, and then the complete image is engaged with an existing portion of the object being fabricated (also referred to herein as a “sample”) and exposed to a non-digital UV curing light source. The only part of the digitization is the material removal, which is done with a laser, so the speed of printing and the robustness of the manufacturing process are significantly improved over conventional additive or 3D fabrication techniques.

[0011] One of the materials best suited for this approach is a high-viscosity material that will not move between the material injection unit and the sample shaping unit, although any material can be used while considering that as the material viscosity decreases, the final resolution of the sample during manufacturing also decreases.

[0012] One embodiment of a negative 3D printing system configured according to the present invention includes a coating system based on a film and rollers, a laser emission system positioned above the material reuse unit, and a sample shaping unit where the film contacts the sample during UV curing. Another optional unit is a sample peeling unit that can operate using mechanical, chemical, or optical (e.g., laser) means, or any combination of these techniques.

[0013] [[ID=Eleven]] [[ID=Twelve]] The coating system can be implemented in any of several ways. For example, in one embodiment, the coating system can include a syringe with a film forming unit where the applied film passes between two rollers. Other coating techniques that can be used can include conventional screen printing, dispenser unit(s) printing, microgravure coating, slot die coating, inkjet printing, or roller coating.

[0014] Coating can be performed, for example, in a controlled environment to prevent evaporation or oxidation of the solvent and to minimize material waste for subsequent reuse. In some embodiments, it can be implemented in a closed loop, where the material applied onto the film passes through a reuse unit, with a small addition of material to the previously unused portion with each cycle.

[0015] The coating system can optionally support 3D printing of multiple materials.

[0016] The negative digital laser ablation system can include a pulsed laser with sufficient energy to ablate a negative image of the material from the film surface. Lasers that can be employed for such purposes can include infrared (IR) lasers, ultraviolet (UV) lasers, carbon dioxide (CO2) lasers, etc.

[0017] The film used for material transfer needs to be a transparent film, at least transparent (or nearly so) to the wavelength of the laser used, regardless of the presence or absence of a coating on the film. Examples of transparent films that can be used are polyethylene terephthalate (PET), biaxially oriented polypropylene (BOPP), polyimide (PI), etc.

[0018] The coating of the film is used to enhance the ejection of material from the film to the material reuse system. For this purpose, a metal or other polymer coating with additives that absorb at the laser wavelength and create digitally transparent regions upon exposure to the negative laser ablation system can be used.

[0019] As described above, the list of materials that can be used for 3D printing using this system is very wide, and it is not realistic to enumerate all possible materials in detail. As an example, possible materials can be UV curable monomers and polymers, viscose or sensitive materials, acrylates, epoxies, urethanes, adhesives, pastes, etc., as well as UV curable monomers and polymers with additives such as ceramics, metals, organic additives, fiber reinforcing agents, or UV / visible light curable material formulations with UV curable waxes.

[0020] This system can be used for low-viscosity or high-viscosity materials that cure or partially cure with light, and can also be used for materials that cure with heat, such as ceramic and metal pastes, solder pastes (epoxy-based or urethane-based), or silicone-based materials, regardless of the presence or absence of UV curable ends. The reaction can proceed by light, by heat, or by other catalysts (such as Pt, OH, etc.), or by a combination of these mechanisms.

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

[0022] The curing system used in the embodiments of this system is not a digital process, and thus curing means within a boundary range can be employed. For example, it is possible to use a UV or visible light curing system, similar to an IR or other thermal curing system (as a post-treatment). It is also possible to use a catalyst with chemical potential for the curing reaction.

[0023] As an example, a basic UV formulation can use monomers and polymers such as acrylates, epoxies, urethanes, and other UV or light-sensitive materials together with a photoinitiator or / and co-initiator or sensitizer, such as acetophenone, thioxanthone, phosphine oxide, iodonium, and sulfonium salts.

[0024] The configuration of the sample peeling system can depend on the chemical properties of the film, involve some kind of laser ablation or top surface cleaning after curing, and / or be a mechanical system. Any of a plurality of techniques can be used, for example, a system that provides low-angle peeling in the Y-axis direction (e.g., by moving the film away from the sample at a small angle), or a system that provides two Z-axes, one axis with respect to the frame (which holds the film) and the other axis with respect to the sample, or a system that provides acoustic vibrations to peel the film from the sample.

[0025] These and other embodiments of the present invention will be described in detail below. The present invention is shown, by way of non-limiting example, in the figures of the accompanying drawings.

Brief Description of the Drawings

[0026]

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[0027] The present invention relates to a method and apparatus for fabricating a solid three-dimensional object from a liquid polymerizable material with high resolution. In one embodiment, a system configured in accordance with the present invention employs the steps of laser emitting a negative image of a film initially coated with a polymerizable liquid with high resolution and exposing that image to a corresponding light source during contact of the film with a sample to produce a next layer of the sample. Since this is a continuous sequence of manufacturing processes, the formation speed and versatility of 3D objects are improved compared to conventional 3D printing processes. However, before explaining the present invention in detail, it is helpful to present an overview. FIG. 1 provides such an overview and shows some components of a system 100 configured in accordance with the present invention: step 10 of applying a material to a film, step 12 of removing excess material into a recovery system, and step 14 of exposing the applied film to a non-digital curing system (based on UV or heat) during contact with a sample.

[0028] By dealing with the negative image of the desired image, several important basic features of the present invention become apparent. First, the excess of the material due to the coating process can be reused, and no significant waste is generated during the sample construction process. Second, a support material is not required (however, as will be described later, the use of a support material remains an option). During curing and contact, the negative image is supported on its upper surface by the film, so in most cases, a support material is not needed. Depending on the structure, additional support may be required or there may be a benefit to it, so the present invention takes such options into account. Third, the system configured according to the present invention has the ability to print at a very high speed because injection and shaping are performed in two different regions and these processes can be carried out simultaneously. The main limitation of the printing speed is either the curing process or the negative printing time, but the timing of these individual processes is not additive, that is, the overall printing speed is not limited by the additive combination of the curing time and the negative printing time. Also, since the curing process is not digital, the constraints on the UV light source used for curing are fewer than those of the conventional 3D printing process.

[0029] The negative printing unit can be a laser-assisted deposition / laser dispensing system equipped with a pulsed laser having sufficient energy to inject the negative image of the material from the film surface to the recovery unit. The laser can be UV, IR, CO2, or some other laser.

[0030] When the printing unit is a laser-assisted deposition / laser dispensing system, the evenly coated substrate plays an important role in the robustness of the system. Therefore, an additional coating system is added in front of the printing unit. This coating system can be a conventional coating system, such as a coating system based on a microgravure coater 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 present invention, the coating system can be based on a syringe and gap system as shown in FIG. 4. In such a system 400, the material 402 is dispensed from the syringe 404 onto the substrate 406 (e.g., by an air pump or a mechanical pump that drives the material from the syringe onto the substrate), and the coated substrate 408 moves towards a clearly defined gap 410 (e.g., by a motor-driven roller or other actuator) and passes through it. The gap can be defined by a blade or other type of barrier, or by two cylinders (e.g., rollers) arranged in proximity to each other, as shown in FIG. 4.

[0031] After passing through the gap 410, a uniform layer 412 of the material is formed on the substrate, and the laser-assisted deposition / laser dispensing system 414 can inject the material from the coated substrate into the material recovery system. The coated substrate 416 moves from the laser-assisted deposition / laser dispensing system 414 to the curing station 418 and contacts the receiving substrate 420 in the presence of UV light and / or heat, thereby re a new layer of the article to be fabricated to form curing the material.

[0032] In other embodiments of the present invention, the coating system can include a screen printing module, in which case the material is applied using a blade or squeegee onto a screen or stencil of a film with clearly defined holes, and the material is transferred to the substrate in a soft or hard engagement. Alternatively, the coating system can include a dispenser or an inkjet head for printing the material onto a carrier substrate. Or, the coating system can be a gravure or microgravure system for applying a highly uniform layer of the material onto the substrate. In yet another embodiment, the coating system can be a slot die system for applying a highly uniform layer of the material onto the substrate. Or, the coating system can be a roller coating system for applying a highly uniform layer of the material onto the substrate.

[0033] In any of these and / or other embodiments of the present invention, the coating system can be placed within a closed compartment with a controlled environment (temperature, pressure, etc.) to prevent evaporation of the solvent from the printed material or to prevent oxidation of the material, thereby extending the pot life of the material.

[0034] In some embodiments of the present invention, the coating system accommodates two or more materials. This creates the possibility of printing multiple materials onto an intermediate substrate (e.g., a film such as substrate 406 in FIG. 4) in a controlled order and enables printing two or more materials onto a final substrate (e.g., receiving substrate 420 in FIG. 4).

[0035] In one embodiment of the present invention, the intermediate substrate of the coating system is translatable forward and backward (from the perspective of applying the material to the intermediate substrate) in a controlled manner while widening the gap between the coater rollers, giving the possibility of re-applying the printing material multiple times to the same area of the intermediate substrate without roller contamination. Also, such a process reduces (or eliminates) the amount of intermediate substrate consumed during the initial printing process and prevents waste.

[0036] In some embodiments, after the current uniform layer of material applied on the intermediate substrate has been (fully or partially) consumed by printing in the printing unit, the intermediate substrate can loop back to the coating system for recoating or translate back to the coating system to apply a new uniform coating layer for the next printing process.

[0037] The film (or other intermediate substrate) used for printing can be a substrate that is transparent to the laser wavelength, regardless of the presence or absence of a metal (or other) coating. Examples of such films (substrates) are PET, BOPP, PI, etc. This film can be coated with a metal or polymer coating having an additive(s) that absorbs at the laser wavelength and creates digitally transparent regions upon exposure to a negative-type laser jetting system.

[0038] Among the printing materials that can be used in a system configured according to the present invention, there are certain liquid or paste materials. However, the advantages of the system of the present invention mainly exist when highly viscous materials that cannot be properly printed at high resolution by other methods are employed. For example, UV light / visible light curable material formulations, as well as UV curable monomers and polymers of viscose or photosensitive materials, can be printed using the system configured according to the present invention. Other materials that can be printed with the system configured according to the present invention are acrylates, epoxies, urethanes, adhesives, pastes, or inks that use either UV curing or thermal curing. Still other materials that can be printed with the system configured according to the present invention are UV curable monomers and polymers containing additives such as ceramics, metals, organic additives, fiber reinforcing agents, etc. Also, UV curable waxes, low viscosity or high viscosity materials that cure by light or even partially cure, epoxy-based, urethane-based, or silicone-based materials whose reaction is initiated by heat or other catalysts (such as Pt, OH, etc.) regardless of the presence or absence of UV curable ends, ceramic and metal pastes, and solder pastes, biocompatible materials, and thermoplastic materials (at room temperature or at high temperature by adjusting the ambient temperature) can all be printed with the system configured according to the present invention. In possible basic formulations and mechanisms, monomers and polymers of acrylates, epoxies, urethanes, or other UV or light-sensitive materials can be used together with photosensitive initiators or / and co-initiators or sensitizers such as acetophenone, thioxanthone, phosphine oxides, iodonium, and sulfonium salts.

[0039] Figure 2 shows a system 200 constructed in accordance with one embodiment of the present invention. In this system, the material 202 is first dispensed onto the transparent substrate 204 by a coating system 206, such as one using a syringe and gap system as described above. The coated substrate 208 is supplied to a negative printing unit 210 where a negative image of the layer to be added to the sample is created by removing excess material (i.e., the portion of the coating material not added to the sample) from the coated substrate (e.g., via laser ejection). As shown, this excess material can be collected by a material reuse system 212 and returned to the coating system 206 for reuse. As shown, the material 214 remaining on the coated substrate is supplied to a curing system (e.g., a UV curing system) 216 and / or an imaging system and arrives shortly at a sample shaping unit 218 where UV curing and / or drying can be used during contact with the sample 220. By curing / drying while the material is in contact with the sample (i.e., the portion of the article being manufactured that has been formed so far, disposed on the receiving substrate 222), the next layer of the sample is printed directly thereon. Next, a sample peeling system 224 achieves peeling of the sample 220 from the carrier substrate 204.

[0040] Figures 3a - 3m show in detail various steps related to the overall printing process. First, referring to Figure 3a, a negative ejection process 300 is shown. A layer of material 302 is applied on an intermediate substrate (e.g., a film or foil) 304. A laser 306 is used to eject a negative of the image (for the next layer to be printed on the sample) from the coated substrate, taking advantage of the laser absorption characteristics of the material or the metal-coated film. The ejected material 308 is collected (310) by a material recovery unit 312 (or multiple units if multiple materials are used), and this material can be reused later (Figures 3a and 3b). Only a segment of the image material 314 remains on the film 304 for further use (Figure 3c).

[0041] Optionally, as shown in Figure 3d, the image material 314 on the film is exposed to low-power UV light before contact with the sample 326Or it can be exposed to temperature. Some materials, mainly liquid materials, require a high-definition image material boundary before such contact, for example, to avoid a sharp decrease in print resolution. Thus, this treatment can clearly define the boundary of the portion of the material image 314. In such a process, the UV partial curing station 318 can include a gas diffusion system 320 for introducing an inert gas (such as Ar, CO2, He, Ne, etc.) 322 into the working space 324 where the UV light 326 from the 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 flows out through the diffuser 330 towards the working space 324. A gas pressure homogenizer can be used to ensure a constant pressure throughout the system.

[0042] Preferably, the intermediate substrate 304 is coated with a thin metal foil 332 , for example, a 20 nm thick Ti layer. The layer of the metal foil will substantially reduce the transmission of the UV light 326 when present, and only the edges of the material layer 314 close to the contact area with the intermediate substrate 304 are reliably cured or partially cured. As an example, a 20 nm thick Ti layer transmits only about one-tenth of the UV light 326 transmitted by the non-protected area of the intermediate substrate 314. In the area where the metal foil has been removed, for example, by laser ablation or other processes, the UV light 326 will be incident on the edges of the segments of the material layer 304 , and in this case too, only these edges are guaranteed to be cured or partially cured. As an additional preventive measure to prevent unwanted curing or over-curing of the segments of the material layer 314, the gas diffusion system 320 can be made of a non-reflective material so that the UV light 326 does not reflect towards the segments of the material layer 314.

[0043] Due to the presence of the inert gas 322 pumped through the diffuser, any oxygen is purged from the working space 324. The thickness of this working space region is related to the gas pressure when being pushed through the diffuser 330. With the segments of the material layer 314 maintained in the oxygen-purged region of the working space, the UV curing system then cures the bottoms and edges of these segments by exposing them to the UV light 326 from the UV light source 316.

[0044] Figures 3e and 3f present views before and after the contact of the film 304 (i.e., segments of the coating material 314 on the film) with the sample, while Figure 3g shows the UV exposure and shaping of the sample. At this stage, material transfer to the sample can be achieved using either UV exposure or exposure to high temperature (in such cases, a coated polyimide film such as Kapton can be used). As shown, the film 304 is brought to the region where the receiving substrate 334 is present, and the receiving substrate (or, if present, the existing layer of the sample) is brought into contact with the segments of the coating material 314 on the film (e.g., by lifting the state where the receiving substrate is present). Next, the segments of the coating material 314 are cured by exposure to the UV light 336 from the UV light source 338. This may be the same UV light source as described above or a different one. Exposure to the UV light 336 (and / or heat) cures the segments of the coating material to form segments of a new layer 340 of the sample (i.e., the object being fabricated).

[0045] After hardening, the sample remains bonded to the film 304 (via segments of the newly hardened layer 340). Therefore, it is preferable to provide a peeling mechanism. For this purpose, as shown in FIGS. 3h - 3j, the metal coating of the film 304 remains under the material that has just been hardened and can be used for laser wavelength absorption and sample peeling. Thus, the laser itself (used for negative printing) 306 can be used as a sample peeling unit. The laser 306 irradiates the position where segments of the newly hardened layer 340 are present, enabling such separation. Also, using the laser, metal residues 342 that may have been peeled off from the film 304 during sample peeling can be removed from the sample (FIG. 3k), leaving a clean hardened layer 340 present on the sample (FIG. 3l). The result 350 of printing several layers 340 is shown in FIG. 3m.

[0046] FIGS. 4 - 7 show configuration examples of a system for implementing the method of the present invention. In one embodiment of the present invention, only one material is supplied and only one layer is printed. FIG. 4 shows such a configuration. The material 402 is applied onto the film 406, and the laser system 414 removes the negative image, and a plurality of samples 420 to move causing and sequentially contact the film 406 cause . The material 416 hardens during contact, and new samples replace old samples.

[0047] FIG. 5 shows a 3D version of the configuration shown in FIG. 4. In this case, the same sample 520 is repeatedly contacted with the film 406, and each time, new layers 522a, 522b, etc. are added (printed) to the sample. Hardening occurs while the upper part of the sample is in contact with the material of the new layer 524 on the film. However, it should be noted that when the material on the film and the sample are not in direct contact, no transfer from the film to the sample takes place. Therefore, the transfer depends on the area of each unit of the material on the film and the surface structure of the sample.

[0048] One way to overcome this problem is to add a support 602 that will come into contact with the film 406 and thus transfer all the materials 524 on the film to the sample. FIG. 6 shows how the support 602 is used to collect all the materials from the film to the sample.

[0049] FIG. 7 shows how an optional unit 702 for 3D negative printing using a support is used. The optional unit 702 mechanically injects a support 704 (e.g., via a syringe 706) to make the sample height uniform that will come into contact with the film 406 during curing. The sample 520 moves back and forth between the curing position 710 and the support injection position 712 between layers.

[0050] A more advanced configuration of a system configured according to an embodiment of the present invention relates to 3D printing of multiple materials. In such a case, a plurality of coating units are arranged to supply different materials to the transfer film(s), apply different materials to the film(s), remove the negative images for each material from the film(s), and bring the materials into contact with the sample and transfer them there. FIGS. 8A-8B show diagrams before and after contact between a substrate 802 containing a second material 804 and a sample 334 that already has a first material 314. The negative images of different materials are compatible and can coexist in the same layer.

[0051] The film itself can be a transparent anti-adhesive foil. For example, PTFE or PFE, or other anti-adhesive foils can be used to ensure easy peeling of the sample from the film after curing. FIGS. 9a-9b show diagrams before and after the peeling process based on the anti-adhesive properties of the film 902. This technique for sample peeling can be a technique that complements the laser peeling mechanism described above, or the only peeling mechanism used.

[0052] Yet another approach related to sample detachment can be mainly a mechanical approach. FIG. 10 shows a mechanical detachment system 1002 that can function with or without the above-described detachment mechanism. Any of a plurality of mechanical approaches can be used. For example, a low-angle detachment along the "Y" axis can be used by moving the film 406 away from the sample 1004 at a small angle. Alternatively, two Z axes can be used, one for the frame (holding the film 406) and the other for the sample 1004. As another approach, it is conceivable to detach the film 406 from the sample 1004 using acoustic vibrations.

[0053] FIG. 11 shows a material reuse system 1102, which is one additional feature of a system configured according to an embodiment of the present invention. To reduce waste, negative imaging can be performed above a tray or other transport means that collects unused material and re-injects it into the coating unit syringe 404 again.

[0054] The above figures do not show one or more units that control the operation of various systems. One skilled in the art will understand that in many cases such units, often referred to as control devices or similar names, are processor-based units that can be programmed to execute the above processes by sending signals to elements of a coating system, a negative printing unit, a material reuse system, a curing system(s), and a sample peeling system. Optionally, these signals actuate end effectors, rollers, lasers, UV or IR illumination / heating systems, and other elements to perform the above tasks. Such control devices generally include one or more processors that execute computer-readable instructions (i.e., computer programs or routines) that define the methods described herein, and these methods are embodied and executed on a non-transitory computer-readable medium. Such processes can be expressed in any computer language and executed on any suitable programmable logic hardware. Based on or using this, a processor-based control device capable of practicing the method of the present invention will typically include a bus or other communication mechanism for conveying information, a main memory such as a RAM or other dynamic storage device connected to the bus for storing information and the instructions executed by the processor and for storing temporary variables or other intermediate information during the execution of the instructions executed by the processor, and a ROM or other static storage device connected to the bus for storing static information and instructions for the processor. It can also include a storage device such as a hard disk or solid state drive, which can be connected to the bus for storing information and instructions. The control device in question can optionally include a display connected to the bus for displaying information to the user. In such cases, an input device including alphanumeric and / or other keys can also be connected to the bus for communicating information and command selections to the processor. It can also include other types of user input devices such as a cursor control device, which can be connected to the bus for communicating direction information and command selections to the processor and for controlling the movement of the cursor on the display.

[0055] The control device can also include a communication interface connected to the processor, which provides bi-directional wired and / or wireless data communication with the control device, for example, via a local area network (LAN). The communication interface transmits and receives electrical, electromagnetic, or optical signals that carry digital data streams representing various types of information. For example, the control device can be networked with a remote unit to enable data communication to a host computer or other device operated by a user. Accordingly, the control device can exchange messages and data, including diagnostic information for assisting in troubleshooting errors, with the remote unit as needed.

[0056] As described above, a method and apparatus for fabricating a solid three-dimensional object from a liquid polymerizable material at high resolution are described.

Explanation of Reference Numerals

[0057] 200 System 202 Material 204 Transparent Substrate 206 Coating System 208 Substrate Coated with Material 210 Negative Printing Unit 212 Material Recycling System 216 UV Curing System 218 Sample Fabrication Unit 220 Sample 222 Receiving Substrate 224 Sample Peeling System

Claims

System comprising a coating system (206) configured to apply a uniform layer of a liquid polymerizable material (202, 302, 402) to a substrate (204, 304, 406) and supply the coated substrate (208, 408) to a negative printing unit (210, 414), wherein the negative printing unit (210, 414) removes a portion of the liquid polymerizable material from the coated substrate (204, 304, 406) and supplies a resulting version of the coated substrate (416) having a residual segment (314) of the liquid polymerizable material to a sample shaping unit (218), the sample shaping unit (218) engages the coated substrate (416) having the residual segment (314) of the liquid polymerizable material representing an image of a layer of an article being fabricated with a sample (220, 520), and is configured to cure the residual segment (314) of the liquid polymerizable material with ultraviolet (UV) light when the residual segment (314) of the liquid polymerizable material is in contact with the sample (220, 520), and the negative printing unit (210, 414) is a laser-based system including a laser (306) configured to eject material from the coated substrate (208, 408) to a material reuse system (212, 1102).

2. The coating system (206) is a screen printing module configured to apply the liquid polymerizable material using a blade or squeegee onto a screen or stencil of a film with clearly defined holes and further transfer the liquid polymerizable material to the substrate (204, 304, 406) in a soft or hard engagement, a dispenser configured to print the liquid polymerizable material onto the substrate (204, 304, 406), an inkjet head configured to print the liquid polymerizable material onto the substrate (204, 304, 406), a gravure or microgravure system configured to apply the uniform layer of the liquid polymerizable material (202, 302, 402) to the substrate (204, 304, 406), a slot die system configured to apply the uniform layer of the liquid polymerizable material (202, 302, 402) to the substrate (204, 304, 406). A roller coating system configured to apply the uniform layer of the liquid polymerizable material (202, 302, 402) to the substrate (204, 304, 406); A syringe (404) of the liquid polymerizable material, a pump for sending the liquid polymerizable material from the syringe (404) onto the substrate (204, 304, 406), and an actuator configured to convey the applied material (208, 408) toward and through a gap between rollers or a knife to create the uniform layer of the liquid polymerizable material (202, 302, 402) having a thickness defined by the gap (410) on the substrate (204, 304, 406); The system according to claim 1, comprising one of the above.

3. The coating system (206) is configured to apply two or more liquid polymerizable materials to the substrate (204, 304, 406), the system according to claim 1 or 2.

4. The coating system (206) includes a gap (410) and is configured to move the substrate (204, 304, 406) through the gap (410), the system according to claim 2.

5. The substrate (204, 304, 406) 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 layer and a dielectric layer, the system according to any one of claims 1 to 4.

6. The system according to any one of claims 1 to 5, further comprising a support material addition unit (706) configured to inject a support material (602, 704) into the sample (220, 520).

7. Applying a material to the substrate (204, 304, 406) with the coating system (206) to create a coated substrate (208, 408) having a uniform layer of the liquid polymerizable material (202, 302, 402); Conveying the coated substrate (208, 408) to a negative printing unit (210, 414), where a portion of the liquid polymerizable material (202, 302, 402) is removed, leaving an image of a layer of an object of the liquid polymerizable material (314) on the substrate (204, 304, 406), wherein the negative printing unit (210, 414) is a laser-based system having a laser (306), and the removing step includes injecting the liquid polymerizable material from the substrate (204, 304, 406) into a material reuse system (212, 1102) using the laser (306). After a portion of the liquid polymerizable material (202, 302, 402) has been removed, conveying the resulting version of the coated substrate (416) from the negative printing unit (210, 414) to a sample shaping unit (218). Engaging, in the sample shaping unit (218), the liquid polymerizable material (314) remaining on the substrate (204, 304, 406) with a sample (220, 520). Curing, in the sample shaping unit (218), the liquid polymerizable material (314) remaining on the substrate (204, 304, 406) with ultraviolet (UV) light while the liquid polymerizable material remaining on the substrate (204, 304, 406) is in contact with the sample (220, 520). A method comprising the above steps.

8. The uniform layer of the liquid polymerizable material (202, 302, 402) on the substrate (204, 304, 406) is Using an air pump or a mechanical pump, a part of the liquid polymerizable material (202, 302, 402) is sent from the syringe (404) onto the substrate (204, 304, 406), and the substrate (204, 304, 406) is moved towards and through a clearly defined gap (410) between rollers or a knife to create the uniform layer of the liquid polymerizable material having a thickness defined by the gap (410), applying the liquid polymerizable material to a screen or stencil of a film with clearly defined holes, using a blade or squeegee to transfer the liquid polymerizable material to the substrate (204, 304, 406) with a soft or hard engagement, a screen printing module, a dispenser, an inkjet head, a gravure or microgravure system for applying the uniform layer of the liquid polymerizable material (202, 302, 402) to the substrate (204, 304, 406), a slot die system for applying the uniform layer of the liquid polymerizable material (202, 302, 402) to the substrate (204, 304, 406), a roller coating system for applying the uniform layer of the liquid polymerizable material (202, 302, 402) to the substrate (204, 304, 406), the method according to claim 7, produced by one of them.

9. The coating system (206) applies two or more polymerizable materials to the substrate (204, 304, 406), the method according to claim 7 or 8.

10. The coating system (206) includes a gap (410) between rollers or a knife to create the uniform layer of the liquid polymerizable material (202, 302, 402) having a thickness defined by the gap (410), The method further includes the step of moving the substrate (204, 304, 406) through the gap, the method according to claim 7.

11. The substrate (204, 304, 406) 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 layer and a dielectric layer, the method according to any one of claims 7 to 10.

12. The method according to any one of claims 7 to 11, wherein the substrate (204, 304, 406) is roller-conveyed to send the image (314) left by the negative printing unit (210, 414) to the sample shaping unit (218).

13. The method according to any one of claims 7 to 12, further comprising the step of injecting a support material (602, 704) into the sample (220, 520) with a support material addition unit (706).

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