Method and device for producing three-dimensional object

Abstract

The invention relates to a method and an apparatus for producing a three-dimensional object. Methods and apparatus provided by the present disclosure include a dewetting phase and a polymeric liquid, the dewetting phase being immiscible with the polymeric liquid and usable to form a three-dimensional object, where the method does not require a blind spot. In addition, the methods and apparatus use an optically transparent cooling apparatus to mitigate heat generated during manufacturing and use a mobile phase to provide a shear interface to reduce interface adhesion.

Description

[0001] Description of the case

[0002] This application is a divisional application of the invention patent application with the application date of May 31, 2017, the national application number of 201780033733.7, and the invention name of “Method and device for manufacturing three-dimensional objects”. Technical Field

[0003] The present disclosure generally relates to methods and apparatus for making three-dimensional objects. More specifically, the present disclosure relates to methods and apparatus for making solid three-dimensional objects from polymerizable liquids in a bottom-up manner without the need for blind areas or inhibition layers and / or at the interfaces of solid-liquid, liquid-hydrogel, solid-solid or solid-hydrogel phases. The present disclosure also relates to the use of optically transparent cooling devices to mitigate the heat generated during the manufacturing process and the use of mobile phases to provide a shear interface to reduce interfacial adhesion. Background Art

[0004] In conventional additive or three-dimensional manufacturing techniques, the construction of three-dimensional objects is carried out in a stepwise or layer-by-layer manner. More precisely, the layer formation is carried out by curing of photocurable resins under the action of visible or UV light irradiation. Two techniques are known: one in which a new layer is formed on the top surface of the growing object; the other in which a new layer is formed on the bottom surface of the growing object.

[0005] If a new layer is formed on the top surface of the growing object, then after each irradiation step the object under construction is lowered into a resin "pool", a new layer of resin is applied on top, and a new irradiation step is performed. Figure 3 An early example of this technique is given in US Pat. No. 5,236,637 to Hull, 1997. A disadvantage of this "top-down" technique is the need to immerse the growing object in a (potentially deep) pool of liquid resin and to reconstruct a precise overlying layer of liquid resin.

[0006] If new layers are formed at the bottom of the growing object, then after each irradiation step the object under construction must be separated from the bottom plate in the fabrication well. Figure 4An early example of this technique is given in U.S. Pat. No. 5,236,637 to Hull, where a polymerizable liquid floats on top of a non-wetting, immiscible liquid layer. However, such techniques have not yet been commercialized, and the fact is that significantly different techniques for "bottom-up" manufacturing have been implemented. For example, in U.S. Pat. No. 7,438,846, an elastic separation layer is used to achieve "non-destructive" separation of cured materials at the bottom construction plane. Other methods, such as the B9CreatorTM 3D printer sold by B9Creations in Deadwood, South Dakota, USA, use a sliding build plate to induce mechanical cutting after the layer is cured. See, e.g., U.S. Patent Application Nos. 2013 / 0292862 to M. Joyce and 2013 / 0295212 to Y. Chen et al. (both Nov. 7, 2013); see also Y. Pan et al., J. Manufacturing Sci. and Eng. 134, 051011-1 (October 2012). Such methods introduce mechanical steps that may complicate the equipment, slow the process, and / or may deform the final product.

[0007] Some "bottom-up" manufacturing methods, such as the Carbon3D system, utilize "dead zones" or "inhibition layers" in which polymerization is chemically quenched near the build interface. The "dead zone" is created by passing a polymerization inhibitor (e.g., oxygen) partially or completely through a semipermeable membrane to continuously feed the inhibitor to the "dead zone." By preventing polymerization at the interface, adhesion is avoided, and the solidified material can be continuously pulled away from the build area. However, this system has several limitations. Specifically, the "dead zone" is highly sensitive to temperature, and small fluctuations may cause printing failures. In addition, the polymerization reaction is extremely exothermic, and the heat must be dissipated without destroying the "dead zone." However, cooling configurations that effectively dissipate large areas of waste heat - those that provide active cooling mechanisms - also inhibit oxygen penetration and the creation of "dead zones." As a result, the area (i.e., planar width and height) of the build domain is limited to cooling configurations that do not infringe on oxygen delivery to the "dead zone."

[0008] Therefore, there is a need for alternative methods and apparatus for three-dimensional fabrication that can avoid the need for mechanical separation steps in "bottom-up" fabrication. Summary of the invention

[0009] One aspect of the present disclosure provides a method for forming a three-dimensional object, the method comprising: providing an adhesive stage and a component, the component having a dewetting phase, the dewetting phase having a building surface, the adhesive stage and the building surface defining a building area therebetween; providing a polymerizable liquid in the building area, wherein the polymerizable liquid is immiscible with the dewetting phase; and exposing the building area to energy through at least a portion of the dewetting phase to polymerize the polymerizable liquid to form a solid polymer from the polymerizable liquid, and advancing the adhesive stage away from the building surface to form the three-dimensional object composed of the solid polymer, wherein the dewetting phase is not a liquid.

[0010] Another aspect of the present disclosure provides a method for forming a three-dimensional object, the method comprising: providing an adhesive stage, a component and a cooling device, the component having a dewetting phase, the component being located between the cooling device and the dewetting phase, the dewetting phase having a building surface, the adhesive stage and the building surface defining a building area therebetween; providing a polymerizable liquid in the building area, wherein the polymerizable liquid is immiscible with the dewetting phase; and exposing the building area to energy through at least a portion of the optically transparent cooling device and through at least a portion of the dewetting phase to polymerize the polymerizable ink to form a solid polymer from the polymerizable liquid, and advancing the adhesive stage away from the building surface to form the three-dimensional object composed of the solid polymer.

[0011] Another aspect of the present disclosure provides an apparatus for forming a three-dimensional object from a polymerizable liquid, the apparatus comprising: a support; an adhesive stage operably associated with the support, the adhesive stage forming the three-dimensional object on the support; a component having a layer of a dewetting phase thereon, the dewetting phase having a building surface, wherein the dewetting phase is not a liquid, wherein the building surface and the adhesive stage define a building area therebetween; a polymerizable liquid supplier operably associated with the building surface and configured to supply the polymerizable liquid into the building area for solidification or polymerization; an energy source configured to deliver energy to the building area through the component to form a solid polymer from the polymerizable liquid; at least one controller operably associated with the energy source to deliver energy to the building area, the at least one controller also operably associated with the adhesive stage for advancing the adhesive stage away from the building surface at a rate dependent on energy intensity to form the three-dimensional object from the solid polymer.

[0012] Another aspect of the present disclosure provides an apparatus for forming a three-dimensional object from a polymerizable liquid, the apparatus comprising: a support; an adhesive stage operably associated with the support, the adhesive stage forming the three-dimensional object on the support; a component having a layer of a dewetting phase thereon, the dewetting phase having a building surface, wherein the building surface and the adhesive stage define a building area therebetween; an optically transparent cooling device; a polymerizable liquid supplier operably associated with the building surface and configured to supply the polymerizable liquid into the building area for solidification or polymerization; an energy source configured to deliver energy to the building area through the component to form a solid polymer from the polymerizable liquid; and at least one controller operably associated with the energy source to deliver energy to the building area, the at least one controller also being operably associated with the cooling device for cooling the building area, the at least one controller also being operably associated with the adhesive stage for advancing the adhesive stage away from the building surface at a rate dependent on energy intensity to form the three-dimensional object from the solid polymer.

[0013] Another aspect of the present disclosure provides a method for forming a three-dimensional object, the method comprising: providing an adhesive stage and a component, the component having a mobile phase, the mobile phase having a building surface, the adhesive stage and the building surface defining a building area therebetween; providing a polymerizable liquid in the building area, wherein the polymerizable liquid is immiscible with the mobile phase; and exposing the building area to energy through at least a portion of the mobile phase to polymerize the polymerizable liquid to form a solid polymer from the polymerizable liquid, and advancing the adhesive stage away from the building surface to form the three-dimensional object composed of the solid polymer.

[0014] Another aspect of the present disclosure provides an apparatus for forming a three-dimensional object from a polymerizable liquid, the apparatus comprising: a support; an adhesion stage operably associated with the support, the adhesion stage forming the three-dimensional object on the support; a component having a layer of a mobile phase thereon, the mobile phase having a building surface, wherein the building surface and the adhesion stage define a building area therebetween; a polymerizable liquid supplier operably associated with the building surface and configured to supply the polymerizable liquid into the building area for solidification or polymerization; an energy source configured to deliver energy to the building area through the component to form a solid polymer from the polymerizable liquid; and at least one controller operably associated with the energy source to deliver energy to the building area, the at least one controller also operably associated with the adhesion stage for advancing the adhesion stage away from the building surface at a rate dependent on energy intensity to form the three-dimensional object from the solid polymer.

[0015] For the methods and apparatus described herein, it is contemplated that optional features may be selected from the various aspects, embodiments, and examples provided herein, including but not limited to components, conditions, and steps.

[0016] Other aspects and advantages will be apparent to those skilled in the art from a reading of the following detailed description. Although the methods and apparatus are susceptible of embodiments in many forms, the following description includes specific embodiments, wherein it is understood that the disclosure is illustrative and is not intended to limit the invention to the specific embodiments described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic side view of one embodiment of an apparatus useful for practicing methods as disclosed herein, particularly an apparatus having a transparent member, a dewetting phase provided on the transparent member, a polymerizable liquid provided on the dewetting phase, and an adhesive stage.

[0018] Figure 2 is a schematic side view of one embodiment of an apparatus for practicing the methods as disclosed herein, particularly an apparatus having a transparent member, a dewetting phase provided on the transparent member, a polymerizable liquid provided on the dewetting phase, and an adhesive station.

[0019] Figure 3 is a schematic side view of one embodiment of an apparatus for performing continuous polymerization.

[0020] Figure 4 is a side schematic diagram of one embodiment of an apparatus that can be used to implement the methods disclosed herein, particularly an apparatus having a transparent cooling device, a transparent member provided on the transparent cooling device, a dewetting phase provided on the transparent member, a polymerizable liquid provided on the dewetting phase, a bonding station, and additional cooling device elements adjacent to a build area.

[0021] Figure 5 is a side view schematic diagram of one embodiment of an apparatus that may be used to implement the methods disclosed herein, particularly providing a dewetting phase on the end of a fiber optic cable, a transparent member provided in a polymerizable liquid, the dewetting phase and the fiber optic cable, and a bonding station.

[0022] Figure 6 is a schematic side view of one embodiment of an apparatus having a curvilinear dewetting phase that can be used to implement the methods disclosed herein, and is a schematic side view of one embodiment of an apparatus having a curvilinear dewetting phase that can be used to implement the methods disclosed herein.

[0023] Figure 7 is a schematic side view of one embodiment of an apparatus that may be used to implement methods as disclosed herein, particularly by using a beam pen lithography or polymer pen lithography tip array.

[0024] Figure 8 is a diagram of the phase interface and dewetting angle of a three-phase system.

[0025] Fig. 9 is a side schematic diagram of one embodiment of an apparatus that can be used to implement the methods as disclosed herein, particularly an apparatus having a transparent member, a mobile phase provided on the transparent member, a polymerizable liquid provided on the mobile phase, and an adhesive stage, wherein the mobile phase is recycled through a closed loop, the closed loop optionally comprising a filtration unit, a cooling device, and an oxygenation unit.

[0026] Fig.10 is a side schematic diagram of one embodiment of an apparatus for implementing a method as disclosed herein, particularly an apparatus having a transparent member, a mobile phase provided on the transparent member, a polymerizable liquid provided on the mobile phase, and an adhesive stage, wherein the mobile phase is recycled through a closed loop, wherein the closed loop optionally includes a filtration unit, a cooling device, and an oxygenation unit (all shown).

[0027] Fig.11 is a schematic side view of one embodiment of an apparatus having a flowing fluid mobile phase for performing continuous polymerization.

[0028] Fig.12 Yes Fig.11 An expanded view of the flow rate distribution at the construction interface of an embodiment of an apparatus for performing continuous polymerization shown in FIG.

[0029] Fig.13 It is a top view on how an isobaric dispensing nozzle produces a uniform flow distribution of a flowing fluid mobile phase on a transparent member.

[0030] Fig.14 is a schematic side view of one embodiment of an apparatus that may be used to implement methods as disclosed herein, particularly by using a multi-projection light engine.

[0031] Fig.15 is a side schematic diagram of one embodiment of an apparatus that may be used to implement the methods disclosed herein, particularly through a combination of multiple light engines, a transparent cooling device, a transparent member having a dewetting phase thereon, a polymerizable liquid, and a bonding stage, wherein the movement of the bonding stage is determined by a computer-controlled linear actuator. DETAILED DESCRIPTION

[0032] Methods and apparatus for forming three-dimensional objects are provided herein. In some aspects, the method comprises: providing an adhesive table and a member having a dewetting phase thereon, the dewetting phase having a building surface, the adhesive table and the building surface defining a building area therebetween; providing a polymerizable liquid in the building area, wherein the polymerizable liquid is immiscible with the dewetting phase; and exposing the building area to energy through at least a portion of the dewetting phase to polymerize the polymerizable liquid to form a solid polymer from the polymerizable liquid, and advancing the adhesive table away from the building surface to form a three-dimensional object composed of the solid polymer, wherein the dewetting phase is not a liquid. Optionally, the dewetting phase is molecularly smooth. Optionally, the method further comprises a cooling device, which can be arranged to cool the polymerizable liquid in view of the heat generated by the exothermic polymerization reaction. Optionally, the cooling device is transparent and spans the building area and is provided between the light engine and the polymerizing liquid. Optionally, the member is optically transparent. Optionally, the member is oxygen-impermeable.

[0033] In some aspects, the method includes: providing an adhesive station, a component, and a cooling device, the component having a dewetting phase, the component between the cooling device and the dewetting phase, the dewetting phase having a building surface, the adhesive station and the building surface defining a building area therebetween; providing a polymerizable liquid in the building area, wherein the polymerizable liquid is immiscible with the dewetting phase; and exposing the building area to energy through at least a portion of the cooling device and through at least a portion of the dewetting phase to polymerize the polymerizable ink to form a solid polymer from the polymerizable liquid, and advancing the adhesive station away from the building surface to form a three-dimensional object composed of the solid polymer. In an embodiment of the foregoing aspect, the cooling device is optically transparent. Optionally, the component is optically transparent. Optionally, the component is oxygen-impermeable.

[0034] In some aspects, the method comprises: providing an adhesive stage and a component, the component having a mobile phase, the mobile phase having a build surface, the adhesive stage and the build surface defining a build area therebetween; providing a polymerizable liquid in the build area, wherein the polymerizable liquid is immiscible with the mobile phase; and exposing the build area to energy by at least a portion of the mobile phase to polymerize the polymerizable liquid to form a solid polymer from the polymerizable liquid, and advancing the adhesive stage away from the build surface to form a three-dimensional object composed of the solid polymer. Optionally, the mobile phase is recycled through a closed loop. Optionally, the mobile phase moves on the component but is no longer circulated. Optionally, the method further comprises cooling the mobile phase. Optionally, the component is optically transparent. Optionally, the component is oxygen-impermeable.

[0035] Advancing the adhesive stage away from the build surface encompasses embodiments in which the adhesive stage is mounted on an elevator to move the fixed build surface upward and away from the fixed build surface; and / or embodiments in which the adhesive stage is fixed and the build surface is lowered to thereby advance the adhesive stage away from it. Advancing the adhesive stage away from the build surface further encompasses moving the adhesive stage toward the build surface, for example, in an oscillating motion, with the proviso that the net movement of the adhesive stage is away from the build surface.

[0036] The methods disclosed herein provide one or more advantages, such as achieving polymerization directly at the surface of the dewetting phase and the polymerizing liquid, where adhesion is low enough that no mechanical cutting is required between each layer of deposited material. In addition, by utilizing solid, semi-solid, and gel (e.g., hydrogel) dewetting phases, printing can proceed along an omnidirectional axis (i.e., not limited to a horizontal printing plane). Furthermore, the interface between the dewetting phase and the polymerizing layer allows the system to be actively cooled via conventional heat exchangers that can span the entire span of the build domain (i.e., not just the perimeter of the build domain, whereby relying on passive heat diffusion), such as Figure 4 In addition, utilizing a mobile phase provides one or more advantages, such as further minimizing adhesion between the emerging three-dimensional object and the mobile phase, and facilitating replenishment of the polymerizable liquid in the build zone. Additionally, utilizing a mobile phase allows for continuous regeneration of the build surface, removal of particulate matter from the mobile phase, and / or a mechanism for direct active cooling.

[0037] Still further, by utilizing the low adhesion phase interface, there is no need to use an "inhibition zone" or "dead zone" where the action of material deposition is quenched / prevented near the interface. The methods disclosed herein provide an increase in efficiency achieved with respect to the hardware necessary to create the dead zone and the initial time required to establish and stabilize the dead zone. Due to these advantages (in simplified hardware, cooling methods, and build surface regeneration), the methods disclosed herein are able to produce much larger build zones than competing technologies.

[0038] In addition, if Figure 5 As shown in , phase interfaces can be used in an omnidirectional manner in Euclidean build space (e.g., the gel-liquid interface can be horizontal, vertical, or at any combination of Euler angles along which one might wish to print). Figure 6 As shown in , these interfaces can be produced in a curvilinear manner so that they remain molecularly smooth but not flat (e.g., a gel with a radius of curvature can be produced to produce a dome-shaped or twisted building area). As a result, the methods disclosed herein are not limited by the proportions, geometry, or directionality of the building area.

[0039] Polymerizable liquid

[0040] As used herein, "polymerizable liquid" encompasses any small building blocks that combine to form larger structures, for example, monomers / oligomers that are cross-linked by traditional polymer chemistry, small particles / colloidal materials that are bonded together, metal ions that are deposited to form a bulk metal, or any other number of chemical to microscopic building blocks.

[0041] In embodiments, the polymerizable liquid is a state of matter (i.e., phase) separate from a dewetting phase (i.e., a solid dewetting phase having a liquid polymerizable liquid or a pinned bubble dewetting phase beneath a liquid layer of polymerizable liquid). In embodiments, the polymerizable liquid is the same state of matter as the dewetting phase. In embodiments, the polymerizable liquid is a state of matter separate from a mobile phase. In embodiments, the polymerizable liquid is the same state of matter as the mobile phase. The polymerizable liquid is typically immiscible with the dewetting phase and / or the mobile phase.

[0042] In an embodiment, the polymerizable liquid may include monomers or oligomers, particularly photopolymerizable and / or free radical polymerizable monomers and oligomers, and suitable initiators such as free radical initiators. Examples include, but are not limited to, acrylic acid, methacrylic acid, acrylamide, styrene, olefins, halogenated olefins, cycloolefins, maleic anhydride, olefins, alkynes, carbon monoxide, functionalized oligomers, multifunctional curing site monomers, functionalized PEG, etc., including combinations thereof. Examples of liquid resins, monomers, and initiators include, but are not limited to, those described in U.S. Patents Nos. 8,232,043, 8,119,214, 7,935,476, 7,767,728, 7,649,029, WO 2012129968, CN 102715751, and JP 2012210408.

[0043] In an embodiment, the polymerizable liquid comprises an aqueous liquid. In a refinement of the foregoing embodiment, the polymerizable liquid comprises a monomer or oligomer selected from the group consisting of acrylics, methacrylics, urethanes, acrylates, polyesters, cyanoesters, acrylamides, maleic anhydrides, functionalized PEGs, dimethacrylate oligomers, and combinations thereof.

[0044] In an embodiment, the polymerizable liquid comprises an organic liquid. In a modification of the foregoing embodiment, the polymerizable liquid comprises a monomer or oligomer selected from the group consisting of olefins, halogenated olefins, cycloolefins, olefins, alkynes, and combinations thereof. In an embodiment, the organic polymerizable liquid is selected from the group consisting of 1,6-hexanediol diacrylate (HDDA, pentaerythritol triacrylate, trimethylolpropane triacrylate (TMPTA), isobornyl acrylate (IBOA), tripropylene glycol diacrylate (TPGDA), (hydroxyethyl) methacrylate (HEMA), and combinations thereof.

[0045] Acid-catalyzed polymerizable liquid. Although in embodiments, as mentioned above, the polymerizable liquid includes a free radical polymerizable liquid, in other embodiments, the polymerizable liquid includes an acid-catalyzed or cationically polymerizable polymerizable liquid. In such embodiments, the polymerizable liquid includes monomers containing groups suitable for acid catalysis, such as epoxy groups, vinyl ether groups, and the like. Therefore, suitable monomers include: olefins, such as methoxyethylene, 4-methoxystyrene, styrene, 2-methylprop-1-ene, 1,3-butadiene, and the like; heterocyclic monomers (including lactones, lactams, and cyclic amines), such as ethylene oxide, thietane, tetrahydrofuran, oxazoline, 1,3, dioxepane, oxetane-2-one, and the like, and combinations thereof. Suitable (typically ionic or non-ionic) photoacid generators (PAGs) are included in the acid-catalyzed polymerizable liquid, examples of which include but are not limited to onium salts, sulfonium salts and iodonium salts, and the like, such as diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, diphenyliodonium hexafluoroantimonate, diphenyl-p-methoxyphenyl trifluoromethanesulfonate, diphenyl-p-benzylidene trifluoromethanesulfonate, diphenyl-p-isobutylphenyl trifluoromethanesulfonate, diphenyl-p-tert-butylphenyl trifluoromethanesulfonate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium trifluoromethanesulfonate, dibutylnaphthylsulfonium trifluoromethanesulfonate, and the like, including mixtures thereof. See, for example, U.S. Pat. Nos. 7,824,839, 7,550,246, 7,534,844, 6,692,891, 5,374,500, and 5,017,461; see also Photoacid Generator Selection Guide for Electronics and Energy Curable Coatings (BASF 2010).

[0046] Base-catalyzed polymerizable liquids. In some embodiments, the polymerizable liquid comprises a base-catalyzed polymerizable liquid. Suitable base-catalyzed polymerizable liquids include, but are not limited to, malachite green methanol base, which generates a hydroxide when irradiated with green light.

[0047] Hydrogel. In an embodiment, a suitable polymerizable liquid comprises a photocurable hydrogel, such as poly(ethylene glycol) (PEG) and gelatin. PEG hydrogels have been used to deliver a variety of biological agents, including growth factors; however, a great challenge faced by PEG hydrogels crosslinked by chain growth polymerization is the possibility of irreversible protein damage. Before photopolymerization, by including affinity binding peptide sequences in the monomer resin solution, the conditions for maximizing the release of biological agents from the photopolymerized PEG diacrylate hydrogel can be enhanced, thereby allowing sustained delivery. Gelatin is a biopolymer frequently used in the food, cosmetics, pharmaceutical and photographic industries. It is obtained by thermal denaturation or chemical and physical degradation of collagen. There are three types of gelatin, including gelatin found in animals, fish and humans. Gelatin from cold water fish skin is considered safe for pharmaceutical applications. UV or visible light can be used to crosslink appropriately modified gelatin. Methods for crosslinking gelatin include curing derivatives of dyes such as Bengal rose red.

[0048] Silicone resins. Suitable polymerizable liquids include silicones. Silicones may be photocurable or cured using a free radical photoinitiator via a Michael reaction between thiols and vinyl residues. Suitable photoinitiators include, but are not limited to, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, vinylmethoxysiloxane homopolymers, and (mercaptopropyl)methylsiloxane homopolymers.

[0049] Biodegradable resins. Biodegradable polymerizable liquids are particularly important for implantable devices to deliver drugs or for temporary performance applications, such as biodegradable screws and stents (U.S. Pat. Nos. 7,919,162; 6,932,930). Biodegradable copolymers of lactic and glycolic acid (PLGA) can be dissolved in PEG dimethacrylate to give a clear resin suitable for use. Polycaprolactone and PLGA oligomers can be functionalized with acrylic or methacrylic groups to make them effective resins for use.

[0050] Photocurable polyurethanes. Particularly useful polymerizable liquids are photocurable polyurethanes. A photopolymerizable polyurethane composition comprising: (1) a polyurethane based on an aliphatic diisocyanate, poly(hexamethylene isophthalate glycol) and optionally 1,4-butanediol can be formulated to make it hard, abrasion-resistant and stain-resistant (U.S. Pat. No. 4,337,130); (2) a multifunctional acrylate; (3) a photoinitiator; and (4) an antioxidant. The photocurable thermoplastic polyurethane elastomer has a photoreactive diacetylene glycol as a chain extender.

[0051] High-performance resin. In some embodiments, the polymerizable liquid comprises a high-performance resin. Such high-performance resins may sometimes require the use of heating to melt and / or reduce their viscosity, as mentioned above and further discussed below. Examples of such resins include, but are not limited to, resins for materials sometimes referred to as liquid crystal polymers of esters, ester-imides, and ester-amide oligomers, as described in U.S. Patents Nos. 7,507,784 and 6,939,940. Since such resins are sometimes used as high-temperature thermosetting resins, in the present invention, they further include suitable photoinitiators, such as benzophenone, anthraquinone, and fluoroketone initiators (including derivatives thereof), to initiate radiation crosslinking, as further discussed below.

[0052] Additional example resins. Particularly suitable resins for polymerizable liquids for dental applications include EnvisionTEC's Clear Guide, EnvisionTEC's E-Denstone materials. Particularly suitable resins for the hearing aid industry include EnvisionTEC's e-Shell 300 series resins. Particularly suitable resins include EnvisionTEC's HTM140IV high temperature mold material, which can be used directly for vulcanized rubber in molding / casting applications. Particularly suitable materials for making tough and hard parts include EnvisionTEC's RC31 resin. Particularly suitable resins for investment casting applications include EnvisionTEC's Easy Cast EC500.

[0053] Sol-gel polymerizable liquid. In some embodiments, the polymerizable liquid may include a sol solution or an acid-catalyzed sol. Such solutions typically include metal alkoxides in a suitable solvent, including silicon and titanium alkoxides, such as tetraethoxysilane (tetraethyl orthosilicate; TEOS). Therefore, products with various properties can be produced, ranging from rubber materials (e.g., using silane-terminated silicone rubber oligomers) to very rigid materials (glass using only TEOS), as well as properties between TEOS combinations and various silane-terminated oligomers. As known in the art, additional ingredients such as dyes and dopants may be included in the sol solution, and a post-polymerization firing step known in the art may be included. See, for example, U.S. Patents Nos. 4,765,818, 7,709,597, 7,108,947, 8,242,299, 8,147,918, 7,368,514.

[0054] Additional resin components. In an embodiment, the polymerizable liquid includes particles or colloidal substances that can be bonded together. In an embodiment, the polymerizable liquid includes metal ions that can be deposited to form bulk metal. The polymerizable liquid resin or material may have solid particles suspended or dispersed therein. Depending on the final product being manufactured, any suitable solid particles can be used. The particles can be metals, organics / polymers, inorganics, ceramics, or composites or mixtures thereof. The particles can be non-conductive, semi-conductive, or conductive (including metals and non-metallic or polymer conductors); and the particles can be magnetic, ferromagnetic, paramagnetic, or non-magnetic. The particles can be of any suitable shape, including spherical, elliptical, cylindrical, and the like. The particles can include an active agent, but as described below, these particles can also be dissolved in the liquid resin. For example, magnetic or paramagnetic particles or nanoparticles can be used.

[0055] Also depending on the specific purpose of the product being manufactured, the polymerizable liquid may have additional ingredients dissolved therein, including pigments, dyes, active or pharmaceutical compounds, detectable compounds (e.g., fluorescent, phosphorescent, radioactive), etc. Examples of such additional ingredients include, but are not limited to, proteins, peptides, nucleic acids (DNA, RNA) such as siRNA, sugars, small organic compounds (drugs and drug-like compounds), etc., including combinations thereof.

[0056] The polymerizable liquid may further include one or more additional components dispersed therein, including carbon nanotubes, carbon fibers, and glass filaments.

[0057] A polymerizable liquid carrying living cells. In some embodiments, a polymerizable liquid may carry living cells as "particles" therein. Such polymerizable liquids are typically aqueous, and may be oxygenated, and may be considered to be "emulsions" in which living cells are discrete phases. Suitable living cells may be plant cells (e.g., monocots, dicots), animal cells (e.g., mammals, avian, amphibian, reptile cells), microbial cells (e.g., prokaryotes, eukaryotes, protozoa, etc.), etc. The cell may be a differentiated cell from or corresponding to any type of tissue (e.g., blood, cartilage, bone, muscle, endocrine glands, exocrine glands, epithelium, endothelium, etc.), or may be an undifferentiated cell such as a stem cell or progenitor cell. In such embodiments, the polymerizable liquid may be a liquid that forms a hydrogel, including but not limited to those described in U.S. Pat. Nos. 7,651,683, 7,651,682, 7,556,490, 6,602,975, and 5,836,313.

[0058] In some embodiments, the polymerizable liquid further includes a photoinitiator. The photoinitiator used depends on the wavelength of the light source used. When a higher energy UV source (i.e., a high pressure mercury lamp emitting in the range of 200nm to 400nm) is used, suitable initiators include but are not limited to 4,4'-bis(diethylamino)benzophenone (trade name Irgacure EMK) (whose primary absorbance is centered around 370nm), phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (trade name Irgacure 819) (whose primary absorbance is centered around 300nm and secondary absorbance is 370nm), diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (trade name Duracure TPO) (whose primary absorbance is centered around 380nm and secondary absorbance is 370nm and 390nm), and bis(2,6-difluoro-3-(1-hydropyrrol-1-yl)phenyl)titanocene (trade name Irgacure 784, Omnicure 784) (whose primary absorbance is 300 nm with strong secondary absorbances at 398 nm and 470 nm). See also Key Product Selection Guide for Photoinitiators for UV Curing 2003 (Ciba Specialty Chemicals 2003).

[0059] In an embodiment, the photoinitiator is phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide. Without intending to be bound by theory, it is believed that at a concentration of 0.5%wt, despite the low solubility of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, the total absorption coefficient and active wavelength make it the most versatile initiator. In addition, since its secondary absorbance is 370nm (which is broad enough to extend into the visible domain), phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide can be easily polymerized by UV sources (mercury lamps), UV-blue LEDs (centered at 405nm), standard off-the-shelf DLP computer projectors, and ambient fluorescent lamps.

[0060] Furthermore, due to its secondary absorbance at 370 nm (which is broad enough to extend into the visible domain), phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide can be easily polymerized by UV sources (mercury lamps), UV-blue LEDs (centered at 405 nm), standard off-the-shelf DLP computer projectors, and ambient fluorescent lighting.

[0061] In some embodiments, the photoinitiator is bis(2,6-difluoro-3-(1-hydropyrrol-1-yl)phenyl)titanocene (trade name Irgacure 784, Omnicure 784), which has a primary absorbance at 300 nm with strong absorption. Absorbance at 398 nm and 470 nm. Without intending to be bound by theory, bis(2,6-difluoro-3-(1-hydropyrrol-1-yl)phenyl)titanocene allows polymerizable liquids to be cured using visible light (blue to green sources) and multiple other sources (e.g., commercially available LED backlit LCD displays).

[0062] In some embodiments, the polymerizable liquid further comprises a surfactant. The surfactant may be included in the polymerizable liquid to reduce the interfacial surface tension between the polymerizable liquid and the dewetting phase and / or the mobile phase. Exemplary surfactants include, but are not limited to, partially fluorinated acrylic polymers (e.g., Capstone FS-22 and Capstone FS-83 from DuPont (Wilmington, DE)), ionic surfactants, including, but not limited to, cetyltrimethylammonium bromide (CTAB), cetylpyridinium chloride (CPC), dimethyldioctadecylammonium bromide (DOAB), sodium dodecyl sulfonate (SDS), sodium dodecylbenzene sulfonate (SDBS), and nonionic surfactants, including, but not limited to, hexaethylene glycol mono-n-dodecyl ether (C12EO6), polyoxyethylene (2) sorbitan monolaurate (Tween-20; Polysorbate 20), and Tyloxapol.

[0063] Mobile phase

[0064] The mobile phase can be any material that is immiscible and / or insoluble with the polymerizable liquid and moves during the polymerization process. In an embodiment, the mobile phase is a dehumidifying phase, as described herein. The movement of the mobile phase can be described relative to the newly emerged object including the cured polymeric material and / or relative to the energy source responsible for the cured polymeric liquid. In an embodiment, the mobile phase moves in a plane, wherein the newly emerged object and / or the energy source are substantially perpendicular to the plane (for example, the mobile phase moves unidirectionally, perpendicular to the advancement of the adhesive stage, or the mobile phase moves rotationally, perpendicular to the advancement of the adhesive stage). In an embodiment, the mobile phase moves in a plane, wherein the newly emerged object and / or the energy source will be substantially perpendicular to the plane, and the newly emerged object and the energy source are also in motion (for example, the newly emerged object and the light engine rotate on a common axis, and the mobile phase moves laterally relative to the object, wherein the axis of rotation is perpendicular to the mobile phase plane.

[0065] In an embodiment, the mobile phase comprises a mobile solid phase, a mobile gel phase, a flowing fluid or a combination thereof. In some cases, the mobile phase comprises a mobile solid. In some cases, the mobile phase comprises a mobile gel. In some cases, the mobile phase comprises a flowing fluid. In some cases, the mobile phase comprises a combination of a mobile solid phase and a flowing liquid.

[0066] The mobile phase may include a mobile solid phase selected from the group consisting of organic solids, aqueous solids, perfluorinated solids, and combinations thereof. Organic solids may include, but are not limited to, squalane, squalene, solid hexadecane, and combinations thereof. Aqueous solids may include, but are not limited to, ice, solid tetraethylene glycol, solid PEG-300 (i.e., polyethylene glycol with a molecular weight of 300 Da), solid PEG-400, solid PEG-600, solid higher molecular weight PEG, and combinations thereof. Perfluorinated solids may include, but are not limited to, perfluoropolyethers, fluorinated ethylene propylene, polytetrafluoroethylene, and combinations thereof. The solid mobile phase may be moved relative to the emerging object, for example, using a conveyor belt.

[0067] The mobile phase may include a mobile gel phase selected from the group consisting of an organogel, a silicone gel, an aqueous hydrogel, a fluorogel, and a combination thereof. The aqueous hydrogel may include, but is not limited to, agar, agarose gel, polyacrylamide gel, starch gel, cationic gel, anionic gel, and a combination thereof. The fluorogel may include, but is not limited to, 2-(perfluorohexyl)ethyl acrylate swollen with a perfluoropolyether.

[0068] The mobile phase may include a flowing fluid. Examples of flowing fluids include aqueous liquids, organic liquids, siloxane liquids, and fluorine liquids. The aqueous liquid may include, but is not limited to, water, deuterium oxide, dense salt solutions, dense sugar solutions, and combinations thereof. Example salts and their solubility limits in water at about room temperature include NaCl 35.9 g / 100 ml, NaBr 90.5 g / 100 ml, KBr 67.8 g / 100 ml, MgBr2 102 g / 100 ml, MgCl2 54.3 g / 100 ml, sodium acetate 46.4 g / 100 ml, sodium nitrate 91.2 g / 100 ml, CaBr2 143 g / 100 ml, CaCl2 74.5 g / 100 ml, Na2 CO3 21.5 g / 100 ml, NH4Br 78.3 g / 100 ml, LiBr 166.7 g / 100 ml, KI 34.0 g / 100 ml, and NaOH 109 g / 100 ml. Thus, for example, 100 ml of a 35.9 g NaCl solution has a density of 1204 kg / m 3 Example sugars and their solubility limits in water at about room temperature include sucrose 200 g / ml, maltose 108 g / 100 ml, and glucose 90 g / 100 ml. Thus, for example, a 60% sucrose aqueous solution has a density of 1290 kg / m3 . Silicone liquids may include, but are not limited to, silicone oils. Silicone oils are liquid polymerized siloxanes with organic side chains. Examples of silicone oils include polydimethylsiloxane (PDMS), dimethyl silicone oil, and cyclosiloxanes. Fluorine liquids may include, but are not limited to, fluorinated oils. Fluorinated oils typically include liquid perfluorinated organic compounds. Examples of fluorinated oils include perfluoro normal alkanes, perfluoropolyethers, perfluoroalkyl ethers, copolymers of substantially fluorinated molecules, and combinations of the foregoing. Organic liquids may include, but are not limited to, organic oils, organic solvents, including, but are not limited to, chlorinated solvents (e.g., dichloromethane, dichloroethane, and chloroform), and organic liquids that are immiscible with aqueous systems. Organic oils include neutral, non-polar organic compounds that are viscous liquids and are hydrophobic and lipophilic at ambient temperature. Examples of organic oils include, but are not limited to, higher density hydrocarbon liquids. In an embodiment, the mobile phase includes silicone liquids, fluorine liquids, or a combination thereof.

[0069] The flow rate of the mobile phase can be maintained in a laminar state to avoid interfacial turbulence while generating a shear flow profile between the polymerizable liquid phase and the mobile phase. When the mobile phase is a flowing fluid, the generation of a laminar flow profile can be facilitated by using a distribution nozzle that generates a series of evenly spaced isobaric mobile phase outlets and the inlet forms a single high flow inlet and outlet (e.g., such as Fig.13 shown).

[0070] In some cases, the mobile phase can be recycled by closed loop. In some cases, the mobile phase moves to the second mobile phase capture reservoir from the first mobile phase supply reservoir, and does not recycle by closed loop. The mobile phase can be collected from the second reservoir, optionally filtered, cleaned and / or purified, and returned to the first supply reservoir to reuse. The mobile phase can be collected from the second reservoir, optionally filtered, cleaned and / or purified, and the flow direction is reversed so that the mobile phase returns to the first reservoir.

[0071] Optionally, the mobile phase is optically transparent. As used herein, unless otherwise specified, "optically transparent" means that the optically transparent element allows 1% to 100% transmittance of energy events to initiate the curing of the polymerizable liquid. In some cases, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% of the energy events are transmitted through the optically transparent element. The optically transparent element can allow transmission of a wide range of wavelengths, including but not limited to wavelengths corresponding to X-ray radiation, ultraviolet (UV) light radiation, visible light radiation, infrared (IR) radiation, and microwave radiation.

[0072] The mobile phase may further comprise a surfactant. The surfactant may be included in the mobile phase to reduce the interfacial surface tension between the polymerizable liquid and the mobile phase. Exemplary surfactants include, but are not limited to, partially fluorinated acrylic polymers (e.g., Capstone FS-22 and Capstone FS-83 from DuPont (Wilmington, DE)), ionic surfactants, including, but not limited to, cetyltrimethylammonium bromide (CTAB), cetylpyridinium chloride (CPC), dimethyldioctadecylammonium bromide (DOAB), sodium dodecyl sulfonate (SDS), sodium dodecylbenzene sulfonate (SDBS), and nonionic surfactants, including, but not limited to, hexaethylene glycol mono-n-dodecyl ether (C12EO6), polyoxyethylene (2) sorbitan monolaurate (Tween-20; Polysorbate 20), and Tyloxapol.

[0073] Dehumidification phase

[0074] Aspects of the methods disclosed herein rely on using phase boundaries as building zones that can be molecularly smooth due to the interfacial surface tension of the dewetting phase and the polymerizable liquid together forming an interfacial system. The dewetting phase and the polymerizable liquid are generally immiscible. In an embodiment, the dewetting phase and the polymerizable liquid are "dewetting", allowing polymerization to occur without strong adhesion between the solidified polymer and the underlying phase. In an embodiment, the dewetting phase can be a mobile phase, allowing polymerization to occur without strong adhesion between the solidified polymer and the underlying phase. Due to these low forces, the solidified "printed" material can be easily lifted from the surface in a continuous manner. In an embodiment, when the polymerizable liquid and / or the dewetting phase are substantially free of surfactants, the contact angle of the dewetting phase and the polymerizable liquid is greater than 60° or greater than 90°. In an embodiment, when the polymerizable liquid is substantially free of surfactants, the contact angle of the dewetting phase with the polymerizable liquid phase is greater than 60°. Unless otherwise indicated, "substantially free of surfactant" as used herein means that the concentration of surfactant is less than about 500 ppm, less than about 250 ppm, less than about 100 ppm, or less than about 50 ppm, or less than about 10 ppm.

[0075] As used herein, "dewetting" means that the phases repel each other and have a contact angle of greater than 60° or greater than 90°. A zero-degree contact angle indicates complete wettability; a contact angle between zero and 90 degrees generally indicates high wettability; a contact angle between 90 and 180 degrees generally indicates low wettability; and a 180-degree contact angle indicates complete non-wetting. It is not necessary to achieve complete dewetting, and in some cases, some lower wettability combinations may be satisfactory, but it is generally preferred to achieve a contact angle of greater than 60° between the polymerizable liquid and the dewetting phase during the polymerization step. If such dewetting cannot be inherently achieved by a specific combination of a polymerizable liquid and a dewetting phase, the wettability between the two liquids can be reduced by including one or more surfactants, cosolvents, pH, or temperature, so as to change the surface tension of the polymerizable liquid and the contact angle at the phase interface. It should be noted that the contact angle is generally defined as a solid-liquid-gas interface. Therefore, wetting is generally defined as a combination of solid, liquid, and gas (when a gas phase is not specified, it is considered to be air at standard temperature and pressure). Furthermore, it should be noted that just because one phase is solid, it does not necessarily mean that the phase will support the weight of the second phase and that it may deform due to that weight. Figure 8 When the bottom phase is not a rigid solid, β does not have to be 180°. As a result, it is easier to define the three phase interfaces in terms of α than θ. When β is not equal to 180°, the dewetting interface can be defined as the interface with a value of α less than 90°, because the dewetting angle has a lower dependence on the deformation of the β phase.

[0076] In addition, the contact angle between two liquids on a solid interface (e.g., a submerged droplet) can be defined, which is typically the case when one observes an immersed surface. As a result, the contact angle is described using all three phases (e.g., a chloroform droplet sitting on a surface submerged in water).

[0077] Without intending to be bound by theory, it is believed that in embodiments in which the dewetting phase is the mobile phase, when the dewetting phase and the polymerizable liquid are substantially free of surfactant, the dewetting phase and the polymerizable liquid can have a higher wettability (e.g., a contact angle less than 90°, e.g., about 60°) because the flow of the dewetting phase provides reduced adhesion, which compensates for the higher wettability.

[0078] Because the methods of the present disclosure allow polymerization to occur without strong adhesion between the cured polymer and the underlying dewetting and / or mobile phase, the polymerizable liquid does not require a blind zone or an inhibition zone. Therefore, in an embodiment, the polymerizing liquid does not contain a blind zone. In addition, because the methods of the present disclosure can use a non-liquid dewetting phase, the interface can be advantageously used in an omnidirectional manner and / or the interface can be generated in a curvilinear manner so that it remains molecularly smooth but not flat. Therefore, in an embodiment, the dewetting phase is curvilinear. In an embodiment, the build surface has no texture.

[0079] In an embodiment, the dehumidifying phase comprises a gel. In an embodiment, the dehumidifying phase is a gel selected from the group consisting of an organic gel, an organic silicone gel, an aqueous hydrogel, a fluorogel, and a combination thereof. In a modification of the aforementioned embodiment, the dehumidifying phase is an aqueous hydrogel, and the aqueous hydrogel is selected from the group consisting of agar, agarose gel, polyacrylamide gel, starch gel, cationic gel, anionic gel, and a combination thereof. In a modification, the dehumidifying phase is a fluorogel, and the fluorogel comprises 2-(perfluorotolyl)ethyl acrylate swollen with a perfluoropolyether.

[0080] In an embodiment, the dehumidifying phase comprises a solid. In an embodiment, the dehumidifying phase is a solid, and the solid is selected from the group consisting of an organic solid, an aqueous solid, a perfluorinated solid, and a combination thereof. In an improvement of the foregoing embodiment, the dehumidifying phase is an organic solid, and the organic solid is selected from the group consisting of squalane, squalene, solid hexadecane, and a combination thereof. In an improvement, the dehumidifying phase is an aqueous solid, and the aqueous solid is selected from the group consisting of ice, solid tetraethylene glycol, solid PEG-300, solid PEG-400, solid PEG-600, and a combination thereof. In an improvement, the dehumidifying phase is a perfluorinated solid, and the perfluorinated solid comprises a solid perfluoropolyether.

[0081] In an embodiment, the dehumidifying phase comprises a gas.

[0082] In an embodiment, the dewetting phase comprises a liquid. The liquid dewetting phase may comprise a water-based liquid, an organic-based liquid, a silicone-based liquid, a fluorinated-based liquid, and combinations thereof. In an embodiment, the liquid dewetting phase comprises a silicone-based liquid, a fluorinated-based liquid, or a combination thereof. The fluorinated-based liquid may include, but is not limited to, perfluoro-n-alkanes, perfluoropolyethers, perfluoroalkyl ethers, copolymers of substantially fluorinated molecules, and combinations of the foregoing.

[0083] In some embodiments, the dewetting phase further includes a surfactant. The surfactant may be included in the dewetting phase to reduce the interfacial surface tension between the polymerizable liquid and the dewetting phase. Exemplary surfactants include, but are not limited to, partially fluorinated acrylic polymers (e.g., Capstone FS-22 and Capstone FS-83 from DuPont (Wilmington, DE)), ionic surfactants, including, but not limited to, cetyltrimethylammonium bromide (CTAB), cetylpyridinium chloride (CPC), dimethyldioctadecylammonium bromide (DOAB), sodium dodecyl sulfonate (SDS), sodium dodecylbenzene sulfonate (SDBS), and nonionic surfactants, including, but not limited to, hexaethylene glycol mono-n-dodecyl ether (C12EO6), polyoxyethylene (2) sorbitan monolaurate (Tween-20; Polysorbate 20), and Tyloxapol.

[0084] In embodiments, the dewetting phase is optically clear.

[0085] Polymerization Initiator / Energy Source

[0086] The production of three-dimensional objects from polymerizable liquids requires an initiating event that induces solidification or deposition of the polymerizable liquid. Deposition can be, for example, photoactivated, electrically activated, thermally activated, and / or magnetically activated. In an embodiment, polymerization is performed by electromagnetic irradiation. In an embodiment, polymerization is performed by electricity. In an embodiment, polymerization is performed by thermal activation. In an embodiment, polymerization is performed by magnetic activation.

[0087] In an embodiment, the method is performed in parallel using a multi-tip array, and the tips of the multi-tip array include the member. The multi-tip array can be from a beam pen lithography system and / or from a polymer pen lithography system. Schematic diagrams of these embodiments are shown in Figure 7 Displayed in.

[0088] Beam Pen Lithography In an embodiment, the multi-tip array is part of a beam pen lithography system. Beam Pen Lithography (BPL) is described, for example, in U.S. Pat. No. 9,021,611, the entire contents of which are incorporated herein by reference. BPL can achieve patterning of submicron features over large areas, with flexible pattern design, convenient, selective pen tip addressability, and low manufacturing cost. Compared to traditional photolithography or contact printing, which can only replicate preformed patterns (i.e., photomasks), BPL can provide the flexibility of producing different patterns by controlling the movement of the tip array on the substrate and / or by selectively illuminating one or more pen tips in the tip array (e.g., selectively allowing energy to pass through one or more pen tips in the tip array to induce polymerization of a polymerizable liquid). Thus, for example, multiple objects can be manufactured in a parallel manner.

[0089] The BPL tip array includes a tip substrate layer and a plurality of tips fixed to the tip substrate layer. The tip substrate layer and the plurality of tips are formed of a transparent polymer. The tip substrate layer and the tips may be formed of the same polymer, or may be formed of different polymers. The tip array further includes a barrier layer coated on the sidewalls of the tips and on portions of the tip substrate layer between adjacent tips. A hole is defined in the barrier layer at the tip (e.g., the photosensitive layer contact end of each tip) so that the transparent polymer tip is exposed through the hole.

[0090] The tip substrate layer can be attached to a transparent (e.g., optically transparent) rigid support, such as formed of glass, silicon, quartz, ceramic, polymer, or any combination thereof. The rigid support is preferably highly rigid and has a highly flat surface on which the tip array is mounted.

[0091] The tip array is non-cantilever and includes tips, which can be designed to have any shape or spacing (pitch) between them as required. The shape of each tip can be the same or different from the other tips of the array, and preferably, the tips have a common shape. Expected tip shapes include ellipsoids, hemispheres, rings, polyhedrons, cones, cylinders and pyramids (triangles or squares). The tip has a base fixed to the tip substrate layer. The base is preferably larger than the tip portion. The edge length range of the base can be about 1 μm to about 50 μm, or about 5 μm to about 50 μm. The preferred tip array contains thousands of tips, preferably with a pyramid shape. The diameter range of the substrate contact (tip) portion of the tip can be about 50nm to about 1 μm. The substrate contact portion of the tip is preferably sharp so that each portion is suitable for forming a submicron pattern, for example, less than about 500nm. The sharpness of the tip is measured by its radius of curvature. The tip may have a radius of curvature, for example, less than about 1 μm. The tip-to-tip spacing (tip pitch) between adjacent tips may range from about 1 μm to about 10 mm.

[0092] The barrier layer on the sidewall of the polymer tip acts as a radiation barrier, allowing radiation illuminating on the surface of the substrate layer opposite to the surface of the fixed tip to be emitted only through the tip exposed by the hole defined in the barrier layer. The exposure of the substrate pre-coated with a resist layer to radiation guided through the tip of the tip array can allow the polymerizable liquid to be polymerized at each tip. The barrier layer can be formed of any material suitable for blocking (e.g., reflecting) a type of radiation in a photolithography process. For example, when used with UV light, the barrier layer can be a metal, such as gold. Other suitable barrier layers include, but are not limited to, gold, chromium, titanium, silver, copper, nickel, silicon, aluminum, opaque organic molecules and polymers, and combinations thereof. The barrier layer can have any suitable thickness, for example, ranging from about 40nm to about 500nm.

[0093] Depending on the specific polymer and the degree of compressibility required for the tip, the polymer material suitable for the tip array can have a linear or branched backbone and can be cross-linked or non-cross-linked. A cross-linking agent refers to a multifunctional monomer capable of forming two or more covalent bonds between polymer molecules. Non-limiting examples of cross-linking agents include, for example, trimethylolpropane trimethacrylate (TMPTMA), divinylbenzene, diepoxides, triepoxides, tetraepoxides, divinyl ethers, trivinyl ethers, tetravinyl ethers, and combinations thereof.

[0094] Thermoplastic or thermosetting polymers can be used, as can cross-linked elastomers. Generally, the polymer can be porous and / or amorphous. Various elastomeric polymer materials are contemplated, including polymers of the general class of siloxane polymers and epoxy polymers. Polymers with low glass transition temperatures can be used, for example, below 25°C or more preferably below -50°C. In addition to compounds based on aromatic amines, triazines and alicyclic main chains, diglycidyl ethers of bisphenol A can also be used. Another example includes novolac polymers. Other elastomeric polymers contemplated include methylchlorosilane, ethylchlorosilane and phenylchlorosilane, polydimethylsiloxane (PDMS). Other materials include polyethylene, polystyrene, polybutadiene, polyurethane, polyisoprene, polyacrylic rubber, fluorosilicone rubber and fluorine-containing elastomers.

[0095] Other examples of suitable polymers that can be used to form the tip can be found in U.S. Pat. No. 5,776,748, U.S. Pat. No. 6,596,346, U.S. Pat. No. 6,500,549, each of which is incorporated herein by reference in its entirety. Other suitable polymers include those disclosed in He et al., Langmuir 2003, 19, 6982-6986, Donzel et al., Adv. Mater. 2001, 13, 1164-1167, and Martin et al., Langmuir, 1998, 14-15, 3791-3795. Hydrophobic polymers such as polydimethylsiloxane can be modified by chemical or physical means such as exposure to a strong oxidant solution or oxygen plasma.

[0096] The polymer of the tip array can be a polymer gel. The gel polymer can include any suitable gel, including hydrogels and organogels. For example, the polymer gel can be a silicone hydrogel, a branched polysaccharide gel, an unbranched polysaccharide gel, a polyacrylamide gel, a polyethylene oxide gel, a cross-linked polyethylene oxide gel, a poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (polyAMPS) gel, a polyvinyl pyrrolidone gel, a cross-linked polyvinyl pyrrolidone gel, a methylcellulose gel, a hyaluronan gel, and combinations thereof. For example, the polymer gel can be an agarose gel. By weight, the gel is mostly liquid, for example, the gel can be greater than 95% liquid, but due to the presence of a cross-linked network in the liquid, it behaves like a solid.

[0097] The material used to form the tip array has a suitable compression modulus and surface hardness to prevent the tip from collapsing during contact with the surface, but too high a modulus and too great a surface hardness may result in a brittle material that is unable to adapt and conform to the substrate surface during exposure. As disclosed in Schmid et al., Macromolecules, 33:3042 (2000), the vinyl prepolymer and the hydrosilane prepolymer may be adjusted to provide polymers of different moduli and surface hardness. Thus, in another class of embodiments, the polymer may be a mixture of a vinyl prepolymer and a hydrosilane prepolymer, wherein the weight ratio of the vinyl prepolymer to the hydrosilane crosslinker is from about 5:1 to about 20:1.

[0098] The tip array and / or the building area can be moved during patterning to form a desired object. For example, in one embodiment, the tip array is moved while the building area remains fixed. In another embodiment, the tip array remains fixed while the building area is moved. In yet another embodiment, both the tip array and the building area are moved.

[0099] When using large 2D arrays of BPL tips (15,000 pens per square centimeter), BPL can be used to do extremely high throughput lithography, producing thousands of 3D objects at a time in parallel. The objects can be identical, such as by using a uniform array of tips. In the alternative, at least some of the objects can be different from each other, such as by using a non-uniformly masked array of tips and lateral displacement of the tip array while printing over the tip pitch dimension.

[0100] Another factor that affects BPL resolution is the tip aperture size, which controls the area exposed to light from the tip. Using near-UV light or halogen light sources and conventional photolithography conditions, objects of about 200 nm close to and below the diffraction limit of light can be produced.

[0101] By moving the surface array while illuminating the tip array from the back side of the tip, for example through the tip substrate layer, a large array of objects can be fabricated simultaneously. Irradiation can be maintained throughout the process.

[0102] Individual tips in a BPL array can be addressed by selective illumination. For example, less than all of the tips in the array can be illuminated, such as one or selectively multiple tips in the tip array. Selective illumination of the tips can be performed, for example, by selectively focusing light through the base of each tip. The tip array can also include one or more spatial light modulators that are capable of blocking certain tips from being exposed to light. The spatial light modulator can be static and / or dynamically controllable. For example, the spatial light modulation can be a shutter. The spatial light modulator can be formed using a variety of materials, including, for example, liquid crystal. The spatial light modulator can be, for example, a mask, which is not dynamically controllable. The spatial light modulator can be placed or formed as part of the tip substrate layer.

[0103] Polymer Pen Lithography In an embodiment, the multi-tip array is part of a polymer pen lithography system. Polymer pen lithography is a direct writing method that provides a collection of molecules in a positive printing mode. Polymer pen lithography utilizes an elastomeric tip without using a cantilever. The tip is preferably made of polydimethylsiloxane PDMS. The preferred polymer pen array contains thousands of tips, preferably having a pyramidal shape, which can be made from a master prepared by conventional photolithography and subsequent wet chemical etching. The tips are preferably connected by a common substrate, which includes a thin polymer backing layer (50 to 100 μm thick), which is preferably adhered to a rigid support (e.g., glass, silicon, quartz, ceramic, polymer, or any combination thereof) before or by curing the polymer. The rigid support is preferably highly rigid and has a highly flat surface on which the array (e.g., silica glass, quartz, etc.) is mounted. The rigid support and thin backing layer significantly improve the uniformity of the polymer pen array over a large area (e.g., a three-inch wafer surface) and make it possible to flatten and uniformly and controllably use the array. Polymer tip arrays are disclosed, for example, in WO 2009 / 132321, the disclosure of which is incorporated herein by reference in its entirety.

[0104] In an embodiment, one or more of the array tip, the backing layer and the rigid support is at least translucent, and preferably transparent.

[0105] The tip array is non-cantilevered and includes a tip, which can be designed to have any shape or spacing between them as required. The shape of each tip can be the same or different from the other tips of the array. Expected tip shapes include ellipsoids, hemispheres, rings, polyhedrons, cones, cylinders and pyramids (triangles or squares). The sharpness of the tip is measured by its radius of curvature, and the radius of curvature of the tip disclosed herein is less than 1 μm. The tip array can be formed by a mold made using a photolithography method, and then a polymer as disclosed in this article is used to form the tip array. The mold can be designed to contain multiple tips arranged in any desired manner. The tip of the tip array can be any desired number, and the expected number of tips includes about 1000 tips to about 15 million tips or more.

[0106] Polymer can be any polymer with compressibility compatible with photolithography.Depending on the specific polymer and the required compressibility of the tip, the polymer material suitable for the tip array can have a straight or branched backbone, and can be cross-linked or non-cross-linked.Crosslinking agent refers to a multifunctional monomer capable of forming two or more covalent bonds between polymer molecules.Non-limiting examples of crosslinking agents include, for example, trimethylolpropane trimethacrylate (TMPTMA), divinylbenzene, diepoxide, triepoxide, tetraepoxide, divinyl ether, trivinyl ether, tetravinyl ether and combinations thereof.

[0107] Thermoplastic or thermosetting polymers can be used, as can cross-linked elastomers. Generally, the polymer can be porous and / or amorphous. Various elastomeric polymer materials are contemplated, including polymers of the general class of siloxane polymers and epoxy polymers. Polymers with low glass transition temperatures can be used, for example, below 25°C or more preferably below -50°C. In addition to compounds based on aromatic amines, triazines and alicyclic main chains, diglycidyl ethers of bisphenol A can also be used. Another example includes novolac polymers. Other elastomeric polymers contemplated include methylchlorosilane, ethylchlorosilane and phenylchlorosilane, polydimethylsiloxane (PDMS). Other materials include polyethylene, polystyrene, polybutadiene, polyurethane, polyisoprene, polyacrylic rubber, fluorosilicone rubber and fluorine-containing elastomers.

[0108] Other examples of suitable polymers that can be used to form the tip can be found in U.S. Pat. No. 5,776,748, U.S. Pat. No. 6,596,346, U.S. Pat. No. 6,500,549, each of which is incorporated herein by reference in its entirety. Other suitable polymers include those disclosed in He et al., Langmuir 2003, 19, 6982-6986, Donzel et al., Adv. Mater. 2001, 13, 1164-1167, and Martin et al., Langmuir, 1998, 14-15, 3791-3795. Hydrophobic polymers such as polydimethylsiloxane can be modified by chemical or physical means such as exposure to a strong oxidant solution or oxygen plasma.

[0109] The material used to form the tip array has a suitable compression modulus and surface hardness to prevent the tip from collapsing during contact with the surface, but too high a modulus and too great a surface hardness may result in a brittle material that is unable to adapt and conform to the substrate surface during exposure. As disclosed in Schmid et al., Macromolecules, 33:3042 (2000), the vinyl prepolymer and the hydrosilane prepolymer may be adjusted to provide polymers of different moduli and surface hardness. Thus, in another class of embodiments, the polymer may be a mixture of a vinyl prepolymer and a hydrosilane prepolymer, wherein the weight ratio of the vinyl prepolymer to the hydrosilane crosslinker is from about 5:1 to about 20:1.

[0110] Compared to the electrical resistance of a glass surface (as described in Schmid et al., Macromolecules, 33:3042 (2000), p. 3044), the material used to form the tip array preferably has a surface hardness of glass of about 0.2% to about 3.5%, as measured by the resistance of the surface to penetration by a hard sphere having a diameter of 1 mm. The surface hardness may optionally be about 0.3% to about 3.3%, about 0.4% to about 3.2%, about 0.5% to about 3.0%, or about 0.7% to about 2.7% of that of glass. The polymer of the tip array may have a compression modulus of about 10 MPa to about 300 MPa. The tip array preferably comprises a compressible polymer that is Hookean at a pressure of about 10 MPa to about 300 MPa. The linear relationship between the pressure applied to the tip array and the feature size allows the near field and feature size to be controlled using the disclosed methods and tip arrays.

[0111] The tip array may include a plurality of tips, which are fixed to a common substrate and formed by a polymer as disclosed herein. The tips may be arranged randomly or in a regular periodic pattern (e.g., in columns and rows, in a circular pattern, etc.). The tips may all have the same shape or be configured to have different shapes. The common substrate may include an elastomer layer, which may include the same polymer that forms the tips of the tip array, or may include an elastomer polymer different from the elastomer polymer of the tip array. The elastomer layer may have a thickness of about 50 μm to about 100 μm. The tip array may be fixed or adhered to a rigid support (e.g., glass, such as a slide). In various conditions, the common substrate, the tip array and / or the rigid support (if present) are translucent or transparent. In certain conditions, each is translucent or transparent.

[0112] Method of forming 3D objects

[0113] In an embodiment, once the polymerizable liquid and the dewetting phase are supplied together in a suitable apparatus, the fabrication of the three-dimensional object can begin, e.g. Figures 1 to 3In an embodiment, once the polymerizable liquid and the mobile phase are supplied together in a suitable device, the fabrication of the three-dimensional object can begin, e.g. Figures 9 to 11 The fabrication can be done layer by layer or continuously.

[0114] In some embodiments, the advancement steps are performed sequentially in uniform increments (e.g., 0.1 or 1 micron, up to 10 or 100 microns, or more) for each step or increment. In some embodiments, the advancement steps are performed sequentially in variable increments (e.g., each increment ranges from 0.1 or 1 micron, up to 10 or 100 microns, or more) for each step or increment. The size of the increments, as well as the rate of advancement, will depend in part on factors such as temperature, pressure, and the structure of the article being produced (e.g., size, density, complexity, configuration, etc.).

[0115] In other embodiments of the invention, the advancing step is performed continuously at a uniform or variable rate. Note that the manufacture of the product can be continuous (as opposed to layer by layer) even when the advancing step is performed in increments.

[0116] In some embodiments, again depending on factors such as temperature, pressure, structure of the article being produced, radiation intensity, etc., the advancement rate (whether performed sequentially or continuously) is about 0.1, 1 or 10 microns / second, up to about 100, 1,000 or 10,000 microns / second. In an embodiment, the arm of the adhesive stage is maintained, and thus the print is retracted from the building surface at a constant rate of about 10 microns, or about 30 microns / second to about 200 microns, about 180 microns, about 160 microns, about 140 microns or about 120 microns / second, so that the adhesive stage is advanced away from the building surface at a constant rate of about 10 microns / second to about 200 microns / second. In an embodiment, the print is retracted from the building surface at a rate ranging from about 100 microns / second to about 140 microns / second (e.g., 120 microns / second).

[0117] Advancing the adhesive stage away from the build surface may include advancing the adhesive stage at a constant rate from the build surface for a fixed distance, then pausing for a fixed time, and optionally repeating. In some cases, advancing the adhesive stage away from the build surface may include advancing the adhesive stage at a variable rate away from the build surface for a fixed distance, then pausing for a fixed time, and optionally repeating. The cycle of advancing the adhesive stage away from the build surface for a fixed distance and then pausing for a fixed time can provide an effective retraction rate (total retraction displacement over the entire time of the pull-pause cycle) of about 10 microns / second to about 200 microns / second, about 30 microns / second to about 120 microns / second, or about 100 microns / second to about 140 microns / second.

[0118] In some cases, making the adhesive stage advance away from the build surface includes making the adhesive stage advance away from the build surface in an oscillating manner. For example, making the adhesive stage advance away from the build surface in an oscillating manner includes a cycle, and the cycle includes (i) making the adhesive stage advance away from the build surface, and (ii) pushing the adhesive stage back to the build surface. Making the adhesive stage advance away from the build surface in an oscillating manner can further include pausing the adhesive stage between making the adhesive stage advance away from the build surface and pushing the adhesive stage back to the build surface. Making the adhesive stage advance away from the build surface in an oscillating manner can further include pausing the adhesive stage after pushing the adhesive stage back to the build surface. The scope of the effective retraction rate (total retraction displacement carried out during the entire time of the oscillation cycle) can be about 10 microns / second to about 200 microns / second, about 15 microns / second to about 120 microns / second, about 30 microns / second to about 120 microns / second, or about 100 microns / second to about 140 microns / second.

[0119] It has been found that delamination / wrinkling effect occurs in known bottom-up printing systems, and this is because when the printing part advances, the dehumidification phase moves upward and clamps. It is believed that the upward movement and compression of the dehumidification phase are caused by the combination of the interfacial adhesion between the materials and the cavitation force formed when the printing part is away from the interface of the dehumidification phase and the polymerizable liquid. Without intending to be bound by theory, it is believed that by making the adhesive stage advance away from the build surface in an oscillating manner, the delamination effect can be alleviated. For example, the adhesive stage is advanced 500 microns away from the build surface, and then pushed back to 450 microns of the build surface (therefore, there is a net displacement of 50 microns from the build surface). It is believed that large rapid lifting destroys the dehumidification phase adhesion with the solidified object, and therefore reduces surface wrinkling, because the increased force causes faster clamping. In another example, the adhesive stage is advanced 500 microns away from the build surface quickly, and then quickly pushed back to 520 microns of the interface, then the adhesive stage is slowly retracted 50 microns from the build surface, thereby causing the net motion of 30 microns per cycle and the net speed of 120 microns per second. By laminating the previous object onto the newly polymerized object layer at the interface (i.e., 500 micron forward steps followed by 520 micron reverse steps), continuous crosslinking between layers can be achieved. The energy source can be projected continuously to ensure continuous printing. Optionally, the energy source can be intermittent to stop polymerization while the object is not substantially adjacent to the interface.

[0120] In some cases, advancing the adhesive stage away from the build surface comprises a mixture of continuous stretching and oscillating cycles. Without intending to be bound by theory, continuous stretching (with a constant or variable rate) can be used at the beginning of printing to reduce disruption of the printing interface that can occur from oscillating cycles while the adhesive stage is immersed in the polymerizable liquid. Thus, the oscillating cycle can be started after the adhesive stage has been advanced away from the build surface so that the adhesive stage is no longer immersed in the polymerizable liquid.

[0121] In some embodiments, the step of providing a polymerizable liquid is performed by forcing the polymerizable liquid into the building area under pressure. In this case, the advancing step can be performed at a rate of at least 0.1, 1, 10, 50, 100, 500 or 1000 microns per second or more or a cumulative or average rate. Typically, the pressure can be a pressure sufficient to increase the rate of the advancing step by at least 2, 4, 6, 8 or 10 times, compared to the maximum repetition rate of the advancing step in the absence of the pressure. In the case of providing pressure by enclosing the device, such as described above, in a pressure vessel and treating in a pressurized atmosphere (e.g., air, nitrogen-rich air, gas mixture, etc.), 10, 20, 30 or 40 pounds per square inch (PSI), up to 200, 300, 400 or 500PSI or higher pressures can be used. In order to manufacture large irregular objects, higher pressures may be less preferred due to the cost of large high-pressure vessels compared to slower manufacturing times.

[0122] On the other hand, when smaller items are being manufactured, or rods or fibers are being manufactured that can be removed or exited from the pressure vessel through ports or orifices therein, then the size of the pressure vessel can be kept small relative to the size of the product being manufactured, and higher pressures (if desired) can be more easily utilized.

[0123] In embodiments where the method comprises a mobile phase, the mobile phase generates shear forces at the interface between the printed object and the mobile phase, which helps to pull the polymerizable liquid into the build zone, promotes replenishment of the depleted zone of polymerizable liquid generated when the solidified portion is extracted, thereby allowing for improved resolution of the emerging object.

[0124] The method disclosed herein may further comprise cooling at least one of the component, the dehumidifying phase, the mobile phase, and the polymerizable liquid, or any combination thereof. As described herein, cooling of at least one of the component, the dehumidifying phase, the mobile phase, and the polymerizable liquid may be achieved using a cooling device. In some embodiments, the cooling device may be configured to maintain the dehumidifying phase in a non-liquid state. In some embodiments, the cooling device is optically transparent.

[0125] In some embodiments, the irradiating step is performed with patterned irradiation. Depending on the specific item being manufactured, the patterned irradiation can be a fixed pattern, or can be a variable pattern created by a pattern generator (e.g., DLP, LCD, etc.), as described below.

[0126] When the patterned irradiation is a variable pattern rather than a pattern that remains constant over time, then each irradiation step can be of any suitable time or duration, depending on factors such as the intensity of the irradiation, the presence or absence of a dye in the polymerizable material, the growth rate, etc. Thus, in some embodiments, the duration of each irradiation step can be 0.001, 0.01, 0.1, 1, or 10 microseconds, up to 1, 10, or 100 minutes or longer. In some embodiments, the interval between each irradiation step is preferably as short as possible, such as 0.001, 0.01, 0.1, or 1 microsecond up to 0.1, 1, or 10 seconds.

[0127] Exposing the build area to energy can include irradiating the build area with an energy source. Contemplated energy sources include electrical, chemical, magnetic, electromagnetic, photon, acoustic, heating, and combinations thereof. Thus, one or more components of suitable devices of the present disclosure, including but not limited to, members, dehumidifying phases, mobile phases, and / or cooling devices can be optically transparent and / or can allow conversion or transfer of energy provided by an energy source (e.g., electrical, chemical, magnetic, electromagnetic, photon, acoustic, heating, and combinations thereof).

[0128] In some embodiments, the component and the dehumidifying phase can be attached to a fiber projector, where the fiber projector delivers the energy for polymerization. In some embodiments, printing can be performed omnidirectionally.

[0129] The method disclosed herein may further comprise filtering, cleaning and / or purifying the mobile phase. Small light scattering particles that produce polymeric inks can cause turbidity in the mobile phase, which results in a loss of lateral resolution in printing and requires replacement of the interface after a certain number of prints. Filtering, cleaning and / or purifying the mobile phase can remove small scattering particles to reduce turbidity and maintain suitable lateral resolution during long prints or multiple prints.

[0130] By incorporating a cooling device to minimize the exothermic polymerization reaction caused by the overheating at the interface, the turbidity of the mobile phase can be further reduced. The cooling device can cool the mobile phase, which in turn can cool the build zone at the interface of the mobile phase and the polymerizing liquid. In an embodiment, cooling the mobile phase comprises passing the mobile phase through a cooling device. In an embodiment, cooling the mobile phase is through a heat exchanger across the build zone.

[0131] The methods disclosed herein may further comprise oxygenating the mobile phase. Without intending to be bound by theory, it is believed that increasing the oxygen concentration in the mobile phase can further reduce interfacial surface adhesion. Contrary to known methods that rely on oxygen diffusion through the membrane, oxygenating the mobile phase advantageously actively delivers the inhibitor to the location in a controlled manner, rather than relying on passive diffusion.

[0132] Device for forming 3D objects

[0133] Another aspect of the present disclosure provides an apparatus for forming a three-dimensional object from a polymerizable liquid, the apparatus comprising: a support; an adhesive stage operably associated with the support, the adhesive stage on which the three-dimensional object is formed; a member having a dewetting phase thereon, the dewetting phase having a building surface, wherein the dewetting phase is not a liquid, wherein the building surface and the adhesive stage define a building area therebetween; a polymerizable liquid supplier operably associated with the building surface and configured to supply the polymerizable liquid into the building area for solidification or polymerization; an energy source configured to deliver energy to the building area through the member to form a solid polymer from the polymerizable liquid; at least one controller operably associated with the energy source to deliver energy to the building area, the at least one controller also operably associated with the adhesive stage for advancing the adhesive stage away from the building surface at a rate dependent on energy intensity to form a three-dimensional object from a solid polymer.

[0134] In a related aspect, the present disclosure provides an apparatus for forming a three-dimensional object from a polymerizable liquid, the apparatus comprising: a support; an adhesive table operably associated with the support, the adhesive table on which the three-dimensional object is formed; a member having a layer of a dewetting phase thereon, the dewetting phase having a building surface, wherein the building surface and the adhesive table define a building zone therebetween; an optically transparent cooling device; a polymerizable liquid supplier operably associated with the building surface and configured to supply the polymerizable liquid into the building zone for solidification or polymerization; an energy source configured to deliver energy to the building zone through the member to form a solid polymer from the polymerizable liquid; and at least one controller operably associated with the energy source to deliver energy to the building zone, the at least one controller also being operably associated with the cooling device for cooling the building zone, the at least one controller also being operably associated with the adhesive table for advancing the adhesive table away from the building surface at a rate dependent on energy intensity to form a three-dimensional object from a solid polymer.

[0135] The method of the present disclosure can be implemented with a variety of different devices. In the simplest embodiment, a Figure 1 The device shown. In short, such a device includes a container, the container includes an optically transparent member (window) for accommodating a dehumidifying phase, wherein a polymerizable liquid is provided on top of the dehumidifying phase. The window is positioned at the bottom of the container, through which energy can be delivered to the building area to polymerize the polymerizable liquid. The adhesive stage is positioned above the container, and the container gradually and progressively advances the growing three-dimensional object upward and outward from the polymerizable liquid. At least one controller (e.g., a computer with an appropriate interface and program) (not shown) can be provided, which, for example, operates the adhesive stage in response to data of the current temperature of the dehumidifying phase, such as determined by a temperature sensor, and optionally, cools the device. The additional and alternative features of the device and its operation are further discussed below.

[0136] You can use the above Figure 1 There are many variations of the device described in . For example, the energy can be supplied through a window positioned at the bottom of the dehumidifying phase, such as Figure 1 As shown, through one side of the dewetting phase (e.g., assisted by a mirror or mirror assembly within the dewetting phase), it can be achieved with an energy source completely positioned within the polymerizable liquid, and can be achieved with an optical fiber or light pipe having an end within the polymerizable liquid. In an embodiment, the optically transparent member and the dewetting phase are attached to a fiber optic projector, and the fiber optic projector delivers the energy for polymerization.

[0137] The present disclosure further provides an apparatus for forming a three-dimensional object from a polymerizable liquid, the apparatus comprising: a support; an adhesive stage operably associated with the support, the adhesive stage on which the three-dimensional object is formed; a member having a layer of a mobile phase thereon, the mobile phase having a building surface, wherein the building surface and the adhesive stage define a building area therebetween; a polymerizable liquid supplier operably associated with the building surface and configured to supply the polymerizable liquid into the building area for solidification or polymerization; an energy source configured to deliver energy to the building area through the member to form a solid polymer from the polymerizable liquid; and at least one controller operably associated with the energy source to deliver energy to the building area, the at least one controller also operably associated with the adhesive stage for advancing the adhesive stage away from the building surface at a rate dependent on energy intensity to form a three-dimensional object from the solid polymer.

[0138] The method of the present disclosure can be implemented with a variety of different devices. In the simplest embodiment, a Fig. 9 The device shown. In short, such a device includes a container including an optically transparent member (window) for accommodating a mobile phase, wherein a polymerizable liquid is provided on top of the dehumidifying phase. The window is positioned at the bottom of the container, through which energy can be delivered to the build area to polymerize the polymerizable liquid. The adhesive stage is positioned above the container, and the container gradually and progressively advances the growing three-dimensional object upward and outward from the polymerizable liquid. At least one controller (e.g., a computer with an appropriate interface and program) (not shown) can be provided, which operates the adhesive stage. The additional and alternative features of the device and its operation are further discussed below.

[0139] You can use the above Fig. 9 There are many variations of the apparatus described in . For example, the mobile phase may be viewed through a window positioned at the bottom of the mobile phase, through one side of the mobile phase (e.g., within the mobile phase with the aid of a mirror or mirror assembly, such as Fig.14 as shown) to supply energy.

[0140] Typically, the components of the devices disclosed herein can be supports for the dehumidifying phase and / or the mobile phase. Optionally, the components are optically transparent. Optionally, the components allow conversion or transfer of energy provided by an energy source selected from the group consisting of electrical, chemical, magnetic, electromagnetic, photon, acoustic, heating, and combinations thereof. Optionally, the components are impermeable to oxygen. As used herein, "impermeable to oxygen" means that the component transmits less than 5 volume %, less than 3 volume %, or less than 1 volume % of the volume of oxygen contained in the atmosphere to which the component is exposed. The components can be made of glass, low iron and high transparency glass variants (commercially known as sapphire glass), quartz, sapphire, soda lime (BK7) acrylic, fused silica, fused quartz, germanium, borosilicate, silicon nitride, or a combination thereof, as determined by the wavelength of the energy emitted from the light engine.

[0141] As mentioned above, because the methods of the present disclosure allow polymerization to occur without strong adhesion between the cured polymer and the underlying dewetting phase, the polymerizable liquid does not require a blind zone. Therefore, in an embodiment, the device does not include a blind zone or an inhibition zone. In an embodiment, the optically transparent member is oxygen-impermeable. In addition, because the methods of the present disclosure can use a non-liquid dewetting phase and / or a mobile phase, the build surface can be advantageously used in an omnidirectional manner and / or the interface can be produced in a curvilinear manner so that it remains molecularly smooth, but not flat. Therefore, in an embodiment, the dewetting phase is curvilinear. In an embodiment, the build surface is a horizontal surface. In an embodiment, the build surface is a vertical surface.

[0142] In an embodiment, the apparatus comprises a cooling device. Optionally, the cooling device is optically transparent. In an embodiment, the cooling device is operably associated with at least one of the member, the dehumidifying phase, the mobile phase and / or the polymerizable liquid. In an embodiment, the cooling device is a heat exchanger that spans the entire span of the build area. In an embodiment, at least one controller is operably associated with the cooling device and is configured to maintain the dehumidifying phase in a non-liquid state. In an embodiment, the cooling device is operably associated with at least one controller, the at least one controller being configured to control the temperature of at least one of the member, the mobile phase and / or the polymerizable liquid.

[0143] The apparatus of the present disclosure may further include an outlet in communication with the mobile phase fluid and an inlet in communication with the mobile phase fluid. In an embodiment, the inlet is further in communication with a first mobile phase supply reservoir fluid, and the outlet is further in communication with a second mobile phase capture reservoir fluid to allow the mobile phase to flow through the membrane. In an alternative embodiment, the outlet is in communication with the inlet fluid to provide a recirculation loop and allow the mobile phase to flow through the membrane.

[0144] The apparatus of the present disclosure may further comprise: an outlet distribution nozzle in fluid communication with the mobile phase and comprising an outlet; and an inlet distribution nozzle in fluid communication with the mobile phase and comprising an inlet. The distribution nozzle advantageously facilitates the formation of a relatively uniform mobile phase flow over the build stage.

[0145] In embodiments where the outlet is fluidly connected to the inlet to provide a recirculation loop, the recirculation loop may further include a filtration unit provided between the outlet and the inlet along the recirculation loop, the filtration unit being operably associated with at least one controller configured to filter, clean or purify the mobile phase. The recirculation loop may further include a cooling device located between the outlet and the inlet along the recirculation loop, the cooling device being operably associated with at least one controller configured to control the temperature of the mobile phase. The recirculation loop may further include an oxygenation unit located between the outlet and the inlet along the recirculation loop, the oxygenation unit being operably associated with at least one controller configured to control the amount of oxygen provided to the mobile phase. In some embodiments, the recirculation loop includes a filtration unit, a cooling device, and an oxygenation unit. In some embodiments, the recirculation loop includes a filtration unit and a cooling device, a filtration unit and an oxygenation unit, or a cooling device and an oxygenation unit. In some embodiments, the recirculation loop includes a filtration unit. In some embodiments, the recirculation loop includes a cooling device. In some embodiments, the recirculation loop includes an oxygenation unit. In any embodiment in which the recirculation loop comprises two or more than two of a filtration unit, a cooling device, and an oxygenation unit, the filtration unit, the cooling device, and the oxygenation unit may be provided in any order along the circulation loop, for example, in the following order: filtration unit, cooling device, oxygenation unit; filtration unit, oxygenation unit, cooling device; cooling device, filtration unit, oxygenation unit; cooling device, oxygenation unit, filtration unit; oxygenation unit, filtration unit, cooling device; or oxygenation unit, cooling device, filtration unit. In an embodiment, the recirculation loop is operably associated with at least one controller configured to maintain a continuous flow of the mobile phase. Optionally, the flow of the mobile phase is maintained at a constant rate.

[0146] A polymerizable liquid reservoir, conduit, pump level sensor and / or valve may be included to replenish the polymerizable liquid pool (not shown), but in some embodiments, a simple gravity feed may be used. A driver / actuator and associated wiring for the bonding station may be included according to known techniques. The driver / actuator, energy source, and in some embodiments, pump and level sensor may all be operably associated with a suitable controller.

[0147] Depending on the specific polymerizable liquid used, any suitable energy source (or combination of sources) may be used in the apparatus, including electron beams and ionizing radiation sources. In an embodiment, the energy source is configured to provide energy to the build region through a member to form a solid polymer from a polymerizable liquid. In an embodiment, the energy source is a light engine. The light engine delivers energy to induce polymerization events in a patterned and / or controlled manner. Examples of light patterning tools include a digital mirror device or a liquid crystal display (LCD). In an embodiment, the light engine has a light source selected from the group consisting of a mercury light source, a light emitting diode (LED) source, a halogen lamp, and a laser. In an embodiment, the energy source is a thermal controller. In an embodiment, the energy source is a microelectrode array. In an embodiment, the energy source is a photoconductive material. In an embodiment, the energy source is a magnetic flux. In an embodiment, the energy source is selected from the group consisting of electrochemical, electromagnetic, photoconductor, acoustic, heating, circuit, photodiode, grid area, and combinations thereof. In an embodiment, the energy source is selected from the group consisting of electrical, chemical, magnetic, electromagnetic, photon, acoustic, heating, and combinations thereof.

[0148] In an embodiment, the energy source is a source of actinic radiation, such as one or more light sources, in particular one or more ultraviolet light sources. Any suitable light source can be used, such as an incandescent lamp, a fluorescent lamp, a phosphorescent or luminescent lamp, a laser, a light emitting diode, etc., including arrays thereof. The light source preferably comprises a pattern forming element operably associated with a controller. In an embodiment, the light source or pattern forming element comprises a digital (or deformable) micromirror device (DMD) with digital light processing (DLP), a spatial modulator (SLM) or a microelectromechanical system (MEMS) mirror array, a mask (also referred to as a mask), a silhouette or a combination thereof. See U.S. Patent No. 7,902,526. Preferably, the light source comprises a spatial light modulation array, such as a liquid crystal light valve array or a micromirror array or a DMD (e.g., with an operably associated digital light processor, usually under the control of a suitable controller), which is configured to perform exposure or irradiation of a polymerizable liquid without a mask, such as by maskless lithography. See, e.g., U.S. Patent Nos. 6,312,134; 6,248,509; 6,238,852; and 5,691,541.

[0149] While in some embodiments, the support on which the adhesive table is mounted may be an elevator that advances upward and away from the fixed building surface, in other embodiments, the opposite arrangement may be used. That is, the adhesive table may be on a fixed support and the building surface lowered, thereby advancing the adhesive table away from it. Many different mechanical configurations will be apparent to those skilled in the art to achieve the same result, in all of which the building surface is "fixed", i.e., no lateral (X or Y) motion is required or the elastic building surface does not have to stretch and then rebound (with associated advancement and backup of the adhesive table).

[0150] Depending on the choice of material from which the adhesive pad is made, and the choice of polymer liquid from which the article is made, the adhesion of the article to the adhesive pad may sometimes be insufficient to hold the article on the adhesive pad until the article or "build" is completed. For example, the adhesion of an aluminum adhesive pad may be lower than that of a poly(vinyl chloride) (or "PVC") adhesive pad. Therefore, one solution is to use an adhesive pad comprising PVC on a surface on which the article being made is polymerized. If this promotes too much adhesion to facilitate separation of the finished part from the adhesive pad, any of a variety of techniques may be used to further secure the article to the adhesive pad with lower adhesion, including but not limited to the application of adhesive tape such as "Greener Masking Tape for Basic Painting #2025 High Adhesion" to further secure the article to the adhesive pad during manufacture. In addition, a polymer or metal mesh material may be fixed to the stage so that the support formed early in the printing process is polymerized around the mesh, thereby embedding a portion of the adhesive pad into the object itself.

[0151] Soluble sacrificial layer. In some embodiments, a soluble sacrificial layer or release layer can be established between the adhesive stage and the three-dimensional object, so that the sacrificial layer can be subsequently dissolved to conveniently release the three-dimensional object from the adhesive stage after manufacturing is completed. Any suitable sacrificial layer that can be coated or otherwise provided on the adhesive stage can be used, such as an adhesive, and any suitable solvent (e.g., polar and non-polar organic solvents, aqueous solvents, etc., to dissolve the sacrificial release layer), but the sacrificial layer and its corresponding solvent should be selected so that the specific material forming the three-dimensional object itself will not be excessively eroded or dissolved by the solvent. The sacrificial layer can be applied to the adhesive stage by any suitable technique, such as spraying, dipping, painting, etc. Examples of suitable materials for the soluble sacrificial release layer (and non-limiting examples of corresponding solvents) include, but are not limited to: cyanoacrylate adhesives (acetone solvent); poly(vinyl pyrrolidone) (water and / or isopropanol solvent); lacquer (acetone solvent); polyvinyl alcohol, polyacrylic acid, poly(methacrylic acid), polyacrylamide, polyalkylene oxides such as poly(ethylene oxide), sugars and saccharides such as sucrose and dextran (all water or aqueous solvents); etc. In some embodiments, lower surface energy solvents are particularly preferred.

[0152] In some embodiments, the actuator / driver and / or associated controller is configured to only advance the adhesive stage away from the build zone (e.g., is unidirectional). In some embodiments, the actuator / driver and / or associated controller is configured as a continuous drive (as opposed to a stepper drive). The adhesive stage can advance away from the build stage at a constant rate or a variable rate. In an embodiment, the adhesive stage can advance away from the build stage in an oscillating manner.

[0153] The controller for performing the method of the present disclosure can be implemented as a hardware circuit, software or a combination thereof. In one embodiment, the controller is a general-purpose computer that runs software and is operably associated with a monitor, a driver, a pump and other components through suitable interface hardware and / or software. Suitable software for controlling the three-dimensional printing or manufacturing method and apparatus as described herein includes but is not limited to the ReplicatorG open source 3D printing program, the 3DPrintTM controller software from 3D Systems, Slic3r, Skeinforge, KISSlicer, Repetier-Host, PrintRun, Cura, etc., including combinations thereof.

[0154] Process parameters monitored directly or indirectly, continuously or intermittently during the process (e.g., during one, some or all of the filling, irradiating and advancing steps) include but are not limited to energy intensity, temperature of the bonding table, polymerizable liquid in the building area, temperature of the growing product, temperature of the dewetting phase, pressure, advancement speed, pressure, stress (e.g., applied on the bonding table by the manufactured growing product), thickness of the release layer, etc.

[0155] Known parameters that may be used for feedback and / or feedforward control systems include, but are not limited to, expected consumption of polymerizable liquid (e.g., from the known geometry or volume of the article being manufactured), degradation temperature of a polymer formed from the polymerizable liquid, etc.

[0156] Process conditions that are directly or indirectly controlled, continuously or stepwise controlled in response to monitored parameters and / or known parameters (e.g., during any or all of the above-mentioned process steps) include, but are not limited to, the supply rate of the polymerizable liquid, the temperature, the pressure, the advancement rate or speed of the bonding stage, the intensity of the energy provided, the duration of the energy provided (e.g., for each "layer"), etc.

[0157] For example, the temperature of the polymerizable liquid in the build zone or the temperature of the dehumidification phase can be monitored directly or indirectly using an appropriate thermocouple, a non-contact temperature sensor (e.g., an infrared temperature sensor), or other suitable temperature sensor to determine whether the temperature exceeds the degradation temperature of the polymerized product. If so, the process parameters can be adjusted by the controller to reduce the temperature in the build zone and / or the dehumidification phase. Suitable process parameters for such adjustments may include: reducing the temperature with a cooling device, reducing the forward speed of the bonding station, reducing the intensity of the energy provided, reducing the duration of the energy provided, etc.

[0158] Additionally, the intensity of the energy source (e.g., a UV light source such as a mercury lamp) can be monitored with a photodetector to detect a decrease in intensity from the irradiation source (e.g., through its normal degradation during use). If detected, the process parameters can be adjusted by the controller to accommodate the loss of intensity. Suitable process parameters for such adjustments may include: increasing the temperature with a heater, reducing the advancement rate of the bonding station, increasing the power of the light source, etc.

[0159] As another example, control of temperature and / or pressure to increase manufacturing time may be achieved using heaters and coolers (alone, or in combination with each other and each responsive to a controller) and / or using pressure suppliers (e.g., pumps, pressure vessels, valves, and combinations thereof), and / or pressure release mechanisms such as controllable valves (alone, or in combination with each other and each responsive to a controller).

[0160] In embodiments where the energy source is light, the manufacturing speed can increase with increasing light intensity. In some embodiments, the light is concentrated or "focused" at the build area to increase the manufacturing speed. This can be achieved using an optical device such as an objective lens. The manufacturing speed can generally be proportional to the light intensity. For example, the building speed in millimeters per hour can be calculated by multiplying the light intensity in milliwatts per square centimeter by a multiplier. The multiplier can depend on a variety of factors, including those discussed below. A range of multipliers from low to high can be used. At the low end of the range, the multiplier can be about 10, 15, 20, or 30. At the high end of the multiplier range, the multiplier can be about 150, 300, 400, or more.

[0161] Certain optical properties of the light may be selected to facilitate increased manufacturing speed. For example, a bandpass filter may be used with a mercury bulb light source to provide light at 365 ± 10 nm measured at full width at half maximum (FWHM). As another example, a bandpass filter may be used with an LED light source to provide light at 375 ± 15 nm measured at FWHM.

[0162] As mentioned above, the polymerizable liquid used in such a process may be a free radical polymerizable liquid, or an acid catalyzed or cationically polymerizable liquid. Some specific polymerizable liquids will of course cure more quickly or more efficiently than others and therefore be more suitable for higher speeds, but this may be at least partially offset by further increasing the light intensity.

[0163] Generally, lower viscosity polymerizable liquids are more suitable for higher speeds, particularly for making articles with large and / or dense cross-sections (but this can be at least partially offset by increasing the light intensity). Polymerizable liquids with viscosities ranging from 50 or 100 centipoise up to 600, 800 or 1000 centipoise or more (as measured at room temperature and atmospheric pressure using a suitable device such as a HYDRAMOTION REACTAVISC™ viscometer (available from Hydramotion Ltd, 1 York 25 Road Business Park, Malton, York Y017 6YA England)). In some embodiments, the viscosity of the polymerizable liquid can be advantageously reduced, if desired, by heating the polymerizable liquid.

[0164] Manufacturing Products

[0165] The three-dimensional products produced by the methods and apparatus of the present disclosure may be final, finished or substantially finished products, or may be intermediate products intended to be subjected to further manufacturing steps, such as surface treatment, laser cutting, electrical discharge machining, and the like.

[0166] Many different products can be manufactured by the methods and apparatus of the present disclosure, including large models or prototypes, small customized products, miniature or microminiature products or devices, etc. Examples include, but are not limited to, medical devices and implantable medical devices, such as stents, drug delivery reservoirs, functional structures, microneedle arrays, fibers and rods, such as waveguides, micromechanical devices, microfluidic devices, etc.

[0167] The processes described herein can produce products with a variety of different properties. Thus, in some embodiments, the product is rigid; in other embodiments, the product is flexible or elastic. In some embodiments, the product is a solid; in other embodiments, the product is a gel, such as a hydrogel. In some embodiments, the product has shape memory (i.e., substantially returns to a previous shape after deformation, as long as it is not deformed to the extent of structural failure). In some embodiments, the product is monolithic (i.e., formed from a single polymerizable liquid); in some embodiments, the product is a composite (i.e., formed from two or more different polymerizable liquids). The specific properties will be determined by factors such as the choice of the polymerizable liquid used.

[0168] The method and apparatus according to the present disclosure may be better understood with reference to the following examples, which are intended only to illustrate the configuration and are not intended to limit the scope thereof in any way.

[0169] Examples

[0170] Example 1: Organic phase polymerizable liquid: monomer / crosslinker with photoinitiator

[0171] 1,6-Hexanediol diacrylate (HDDA) was used as the basis for the organic phase polymerizable liquid. HDDA was obtained from Sigma-Aldrich or TCI America in the presence of inhibitors (100 ppm monomethyl ether hydroquinone). These inhibitors were removed by alkaline extraction before use. Briefly, 30 mL of 50 mM NaOH solution was added to 15 mL of HDDA monomer solution and shaken. The inhibitor was deprotonated and extracted into the aqueous phase and removed by a separatory funnel. After shaking, the aqueous layer was densified using NaCl (final concentration range of 1 to 2 M) to facilitate separation. Three extractions were then performed - two for 50 mM NaOH 1 M NaCl solution and the last for 1 M NaCl solution. The monomer layer was recovered and dried with magnesium sulfate and then isolated by vacuum filtration.

[0172] Pentaerythritol triacrylate and trimethylolpropane triacrylate (TMPTA) were similarly post-treated to remove the hydroquinone-based inhibitor.

[0173] The polymerizable liquid further comprises a photoinitiator. 0.1 wt.% to 0.5 wt.% of each of 4,4'-bis(diethylamino)benzophenone (primary absorbance centered around 370 nm), phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (primary absorbance centered around 300 nm, and secondary absorbance centered at 370 nm), diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (primary absorbance centered around 380 nm, with secondary absorbance centered at 370 nm and 390 nm) were independently added to the HDDA sample and the HDDA sample was irradiated with a high energy UV source (i.e., a high pressure mercury lamp emitting in the range of 200 nm to 400 nm). All initiators polymerized HDDA.

[0174] Thus, Example 1 demonstrates that an organic polymerizable liquid according to the present disclosure can be polymerized by an energy source according to the present disclosure in the presence of an initiator.

[0175] Example 2: 2D Image Generation

[0176] Printing experiments were performed on dense water (i.e., deuterium dioxide, saturated NaCl solutions, and solutions saturated with CsCl) and fluorinated solvents (perfluoro-n-hexane, perfluoro-n-octane) as dewetting phases. Experiments were performed in fluorescent quartz cuvettes, where 1 to 2 ml of the denser dewetting liquid was added to the bottom of the cuvette and the lighter monomer / initiator mixture from Example 1 was added to the top (e.g., HDDA with 5% Irgacure 819). A mask / pinhole was used to pattern light from a collimated fiber connected to a high pressure mercury lamp. Exposures ranged from 1 second to 30 seconds and resulted in the formation of polymer droplets at the interface.

[0177] Example 3: 3D printing of cylindrical columns

[0178] A fluorescent quartz cuvette containing a dewetting phase and a polymerizable liquid was prepared as in Example 2, however a light quenching dye was added to the polymerizable liquid layer (i.e., a HDDA solution saturated with naphthalene or anthracene with 5% Irgacure 819) to limit light penetration into the polymerizable layer. After this addition, thin polymer disks of approximately 200 μm thick were formed at the dewetting interface. These thin polymer disks were cross-linked to the end of the capillary and, upon slowly retracting from the interface, formed a cured layered structure. The light source could be further modified through a 200 um pinhole and then through a 15X UV transparent microscope objective with a working distance of 3 cm. After irradiation for 30 seconds, polymer dots of approximately 200 μm wide were observed floating at the interface. By focusing the lens to the end of the glass capillary and slowly retracting the capillary from the interface (approximately 100 um / 30 sec), a cylindrical column of approximately 200 um in diameter and several millimeters in length could be formed.

[0179] Example 4: Perfluorinated dehumidifying phase

[0180] As in Example 2, a fluorescent quartz cuvette containing a dewetting phase and a polymerizable liquid is prepared, but perfluorinated oil is used as the dewetting phase. Perfluorinated oils include Krytox GPL-100 and Krytox XHT-1000. Both can be layered on a quartz window in a homemade fluid cell. On top of these fluorinated layers, a polymerizable fluid (HDDA, 5%wt of Irgacure819) is floated on top. One of a plurality of light sources (mercury lamp, UV-blue LED, halogen lamp) is used to irradiate the polymerizable liquid layer through the quartz window supporting the liquid layer. It is observed that polymer patterns are formed at the fluorine-organic interface. These patterns can be controlled by a mask layer, a pinhole or by utilizing a digital micromirror device (DMD). Again, after observing the 2D structure, these structures are polymerized on the end of a capillary or metal AFM chuck and then slowly retracted from the interface using a micropositioner. Using a series of masks (or DMD devices), different patterns can be projected onto the interface to generate non-prismatic 3D structures.

[0181] Example 5: Gel-based dehumidification phase

[0182] A hydrogel comprising 2.5 wt% agar or agarose is formed by dissolving / mixing the agar or agarose solid into DI water and allowing the material to swell for 30 minutes. Thereafter, the mixture is heated to its boiling point in a microwave oven (a plastic cover is loosely applied to prevent evaporation of water from the mixture). The molten mixture is then poured into a Petri dish or pattern (a glass window with about 1 mm silicone spacers on the edges) to form a thin agarose hydrogel window. These windows are cooled, placed in a semi-solid and rinsed / stored in deionized water.

[0183] A quartz window with 1 mm agarose hydrogel on top was clamped in a homemade fluid cell. A polymerizable liquid layer (95% wt. HDDA, 5% wt. Irgacure 819) was added to form a cell about 1 cm deep. As in Example 2, patterned irradiation was first used to generate a 2D image. The 2D "substrate" was then attached to a stage (capillary, metal plate, etc.), which was then retracted from the interface at a rate of 1 um / sec to 50 um / sec. At higher retraction rates (and therefore increased polymerization rates), the excess heat generated by the polymerization reaction caused permanent damage to the hydrogel surface (i.e., the water began to boil and the hydrogel surface deformed). Although these deformations do not limit the dewetting properties of the surface (which produces a curved surface on the resulting object), once the hydrogel is infiltrated and the hydrogel is boiled, it allows contact between the quartz window and the polymerizable fluid and is considered a compromise.

[0184] Similar results were observed for fluorogels previously produced by crosslinking 2-(perfluorohexyl)ethyl acrylate monomers with 1 to 5% wt of 2-hydroxy-2-methylpropiophenone photoradical initiator, followed by swelling with the perfluoropolymer Fluoriner FC-70.

[0185] Thus, Example 5 illustrates a method of forming a three-dimensional object according to the present disclosure using a non-liquid dewetting phase according to the present disclosure.

[0186] Example 6: Using a Cooling Table

[0187] The fluoro oil / polymer-liquid and gel / polymer-liquid systems of Example 4 and Example 5 are used together with a cooling device. A transparent cooling device is filled with dry ice-cooled acetone. The cooled acetone is passed between two optically transparent windows, and the dehumidification phase is continuously cooled. Under the condition of Krytox XHT-100, the coolant solidifies the oil when the temperature drops to below the flow point of the oil (i.e., -5°C). It is important to find that the path between the patterned light source and the bottom of the cooler window (i.e., a closed plastic chamber with a desiccant) is kept dry to minimize ice formation and condensation on the window. Importantly, under all conditions (gel and solidified oil), the cooling window allows rapid and uniform heat dissipation during the polymerization process. In the absence of such cooling, damage occurs at the smooth interface (as described in Example 4) due to the exothermic polymerization reaction at a faster build rate (i.e., a rate exceeding 50 μm / sec). When a cooling stage is used, multiple builds have been repeatedly and reliably produced at a rate ranging from 150 μm / sec to 300 μm / sec. Approximately 100cm has been achieved 2 A cross-sectional area of ​​15 cm and a height of more than 15 cm.

[0188] Thus, Example 6 illustrates a method of forming a three-dimensional object according to the present disclosure using a non-liquid dewetting phase according to the present disclosure and an optically transparent cooling device across the build zone.

[0189] Example 7: Using a cooling stage with a multi-projector system

[0190] A custom aquarium with a low iron glass bottom measuring 14" x 17" x 6" (W x L x H) fitted with 4 1 cm stands so that the bottom of the aquarium is raised off any surface it rests on. Said aquarium will therefore be referred to as the "printed bed", with its bottom constituting the "building block".

[0191] A second, larger sized, low iron glass bottom aquarium was equipped with a distribution nozzle on one side and an overflow outlet on the other side to create an even and unidirectional flow pattern between the inlet and outlet. The inlet and outlet of this aquarium were connected to a recirculating chiller and filtration system that recirculated the ethylene glycol aqueous solution and maintained the bath at a constant temperature ranging from -10°C to 25°C. Therefore, the system (aquarium, nozzles and recirculating chiller) will be referred to as a "chilling station".

[0192] Two consumer grade DLP projectors were modified to emit the maximum amount of UV light from their mercury lamps. This was accomplished by removing the UV filters within the projector housing, removing the "color wheel" responsible for producing red, green, and blue light, and modifying the projection lenses. Two of these projectors were mounted on an optical track system to allow them to be aligned and tiled to produce a projected image over an area of ​​12"x15" with a throw distance of approximately 12". Each projector individually generates an area of ​​12"x 7.5". These projectors are connected to a custom computer system with software capable of projecting a unified image on both tiled projectors and imaging the projected UV light image to a standard computer monitor. The system (aligned UV maximizing modified projectors and computer system) is a "light engine", "optical-engine / opticsengine". When not in use, the projected light from the light engine is eliminated by a shutter mechanism.

[0193] The light engine, cooling stage and print bed are stacked vertically in a support frame to produce Figure 4 The depicted configuration - where patterned UV light is projected upward from a light engine through a UV-transparent cooling stage where a UV-transparent print bed (low iron glass constituting the "build") is placed. Due to the 1 cm spacers supporting the build, ethylene glycol coolant is able to flow under the print bed - to actively cool the dehumidifying phase and dissipate heat generated in the build zone to be formed on top of the build.

[0194] Above the print bed, a 4' linear actuator is mounted attached to a support frame. The actuator is mounted in a configuration that is effectively perpendicular to the plane created by the component (the glass bottom of the print bed). The bracket of the actuator is mounted with a support that holds a "sticking table" (12"×12" multi-well plate) with its plane effectively parallel to the plane created by the component. The linear actuator is connected to the computer system that drives the light engine and is programmed to bring the sticking table 1 cm above the bottom of the print bed (component) and then retract the sticking table in a systematic manner. The net retraction rate of the sticking table ranges from 10 microns / second to a rate of over 180 microns / second. The system is the "actuator" and the "sticking table". Fig.15 A schematic side view of the device is shown in FIG.

[0195] As the adhesive stage was retracted from the print bed, a quantity of fluoro oil (Krytox TM Oil or from Solvay (Alpharetta, GA) Oil) is poured into the print bed to produce a dehumidified phase of about 1 cm thick on the low iron glass member. After this, the light engine is not turned off to produce a projected test image at the air / fluorine oil interface. The projected image is focused and a fine alignment of the tiled projector is performed to ensure that the projected image at the interface is sharp and continuous. Once completed, the light engine is turned off and the image sequence is loaded for subsequent printing. During deblurring, the image sequence will be projected.

[0196] After precise alignment and closing of the light engine, the adhesive stage is brought back to the fluoro oil dewetting phase (bottom of the vertical range of the actuator) and the vertical position of the stage is finely adjusted to just contact the liquid surface. Once in place, the polymerizable liquid is added to the print bed, forming a pool floating on the fluoro oil dewetting phase below. After adding sufficient resin supply, the cooler stage is activated to bring the component and dewetting phase to the appropriate temperature (0°C to 10°C) and maintain the temperature.

[0197] The polymerizable liquid and / or resin described above comprises hexanediol diacrylate (HDDA) reactive monomer, acrylate functionalized block copolymer, and 2% Irgacure 819 photoinitiator (phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide). The mixture of copolymer resin, reactive diluent monomer, and photosimulator is referred to as "polymerizable liquid" or simply "resin".

[0198] After the polymerizable resin is added to the print bed and the temperature of the dehumidification phase is stabilized, the shutter on the light engine is disengaged, allowing the pattern UV-light to enter the print bed. The actuator (and therefore the adhesive stage) is then retracted from the dehumidification phase at a predetermined net rate. In the initial stages of polymerization, the rate is slow to allow stronger adhesion between the newly emerging printed object and the adhesive stage itself. For example, when the object is retracted in an oscillating motion, the retraction rate is no more than about 60 microns / second. When the object is retracted using a continuous motion, the retraction rate is as high as about 120 microns / second. Once the printing table completely emerges from the resin pool, the actuator retraction speed and, accordingly, the image projected by the light engine is increased to a rate of more than 180 microns / second.

[0199] Once the predetermined sequence of images is over, and the printed object is therefore complete, the light engine is turned off. The actuator is commanded to lift the final object from the print bed and allow the residual resin to drip back into the print bed. The printed object, still adhered to the adhesive bed, is removed from the supporting actuator arm and washed in an organic solvent chemical bath to remove the unpolymerized liquid resin from the surface of the printed object. Once fully washed, the "green" body (i.e., not fully cured / solidified) is allowed to dry, carefully removed from the printing bed, and then placed in a UV light oven to fully set its shape and use the expected material properties. After curing in the light oven, the final cured object is used and further tested.

[0200] Thus, Example 7 illustrates a method of forming a three-dimensional object according to the present disclosure using a dehumidifying fluid according to the present disclosure and a transparent cooling device across the build domain. Additionally, Example 7 illustrates faster printing rates (at least about 120 microns / second) over a large area (12" x 15") that was not possible in previous embodiments without an optically transparent cooling device. Additionally, Example 7 illustrates the ability to tile light engines into an array, align the light engines, and print a single continuous object across multiple light engines.

[0201] Example 8: Use cooled mobile phase

[0202] The system utilizes the same light engine, adhesive stage / actuator, and resin as described in Example 7. The two transparent beds constituting the cooling stage and the printing bed are replaced by a single transparent bed with dispensing nozzles mounted on either side of the bed, such as Fig.13 This single transparent bed is a "printed bed" whose low-iron glass bottom forms a building block on which the dewetting mobile phase can be placed.

[0203] As in Example 7, the light engine, print bed, and actuator arm that moves the adhesive stage are stacked vertically using a support frame. As previously described, the light engine projects patterned light upward through the transparent bottom of the print bed (member) and through the fluorinated oil (dewetting phase) to initiate the curing of the resin (polymerizable fluid). The secondary transparent bed that constitutes an optically transparent cooler is not used in the described example - but this is optional.

[0204] Two dispensing nozzles on either side of the print bed serve as inlet and outlet, with fluorinated oil as the mobile phase, which is recirculated through the bed with a relatively uniform flow field across the build area. The 12" x 15" projected area produced by the light engine is located between the two dispensing nozzles. Once pumped from the print bed, the fluorinated oil is optionally filtered, cooled, and oxygenated. In the described embodiment, the oil passes through a filtration system to remove any particulates that could cause undesirable light scattering as well as a cooler, only directly supercooled. Oxygenation of the dehumidified phase is not required, but is optional and can increase the possible final printing speed.

[0205] Once the fluorine oil is placed in the print bed so as to completely immerse the nozzle inlet and outlet, it is recirculated and the adhesive table is retracted from the air-oil interface. At this time, the light engine is not turned off to produce a projected test image at the air / fluorine oil interface. The projected image is focused and a fine alignment of the tile projector is performed to ensure that the projected image at the interface is clear and continuous. Once completed, the light engine is turned off and the image sequence is loaded for subsequent printing. When deblurring, the image sequence will be projected.

[0206] After precise alignment and closing of the light engine, the adhesive stage is brought back to the fluoro oil dewetting phase (the bottom of the vertical range of the actuator), and the vertical position of the stage is finely adjusted so as to just contact the liquid surface. With the adhesive stage in place, the recirculation of the mobile phase is temporarily stopped during the addition of resin to the print bed, thereby forming a resin pool that floats on the fluoro oil dewetting phase below. After adding a sufficient supply of resin, the recirculation of the mobile phase is restarted. Since the dispensing nozzle is located below the fluoro oil / resin interface, the oil is only drawn out through the recirculation loop. Once the recirculation of the oil continues, the cooling device turned on in the recirculation loop is activated until the mobile phase is brought to an appropriate temperature of about 0°C to 10°C.

[0207] After the polymerizable resin is added to the print bed and the mobile phase temperature stabilizes, the shutter on the light engine is disengaged, allowing the patterned UV-light to enter the print bed. The actuator (and therefore the adhesive stage) is then retracted from the dehumidification phase at a predetermined net rate. In the initial stages of polymerization, the rate is slow to allow for stronger adhesion between the emerging printed object and the adhesive stage itself. Once the print stage fully emerges from the resin pool, the actuator retraction speed, and accordingly the image projected by the light engine, is increased to a rate of over 180 microns / second.

[0208] The movement of the dewetting phase relative to the emerging printed objects results in shear forces which reduce the adhesive interactions between these emerging prints and the dewetting phase. As a result, the emerging prints are found to have superior lateral (XY) resolution and surface finish relative to printing from the same phase while being held stationary and cooled as disclosed in Example 7.

[0209] Once the predetermined sequence of images is over, and the printed object is therefore complete, the light engine is turned off. The actuator is commanded to lift the final object from the print bed and allow the residual resin to drip back into the print bed. The cooling and recirculation of the mobile phase are stopped. The printed object, still adhered to the print bed, is removed from the supporting actuator arm and washed in an organic solvent chemical bath to remove the unpolymerized liquid resin from the surface of the printed object. Once fully washed, the "green" body (i.e., not fully cured / solidified) is allowed to dry, carefully removed from the print bed, and then placed in a UV light oven to fully set its shape and react sufficiently for the expected material properties to be used. After curing in the light oven, the final cured object is used and further tested.

[0210] By directly actively cooling the dehumidifying phase - in contrast to Example 7, where a glycol solution was used in a transparent heat exchanger as an intermediate - the heat removal rate during printing is enhanced, providing good thermal stability. In addition, as mentioned above, with known systems, for longer prints, there is often an accumulation of small particulate polymers, which causes undesirable light scattering in the build area and therefore leads to a loss of lateral resolution. This phenomenon in the field of SLA 3D printing is often referred to as "clouding" and the only solution is to replace the dehumidifying phase. In that case, after the print is completed, the dehumidifying phase must be removed and vacuum filtered to remove such particles. Therefore, compared to other technologies, being able to recycle the dehumidifying interface has a great advantage due to continuous filtration and regeneration throughout the print. This is advantageous because it allows the printer to continue printing for a longer time and produce a larger volume before maintenance is required.

[0211] Thus, Example 8 illustrates a method for forming a three-dimensional object according to the present disclosure using a cooled mobile phase. Additionally, Example 8 illustrates a method for continuously regenerating a build interface by removing particulate contaminants formed by a dewetting mobile phase during the printing process and increased printing resolution due to lower adhesion between the mobile phase and the emerging object.

Claims

1. A method for forming a three-dimensional object, comprising: providing an adhesive stage and a component, the component having a dewetting phase thereon, the dewetting phase having a building surface, the adhesive stage and the building surface defining a building area therebetween; providing a polymerizable liquid in the building zone, wherein the polymerizable liquid is immiscible with the dewetting phase; and exposing the build zone to energy through at least a portion of the dewetting phase to polymerize the polymerizable liquid to form a solid polymer from the polymerizable liquid, and advancing the adhesive stage away from the build surface to form the three-dimensional object composed of the solid polymer, in The dehumidifying phase is not a liquid.

2. The method of claim 1, further comprising cooling at least one of the component, the dewetting phase, or the polymerizable liquid.

3. A method of forming a three-dimensional object, comprising: Providing an adhesive stage, a component and a cooling device, the component having a dehumidifying phase, the component being between the cooling device and the dehumidifying phase, the dehumidifying phase having a building surface, the adhesive stage and the building surface defining a building area therebetween; providing a polymerizable liquid in the building zone, wherein the polymerizable liquid is immiscible with the dewetting phase; and Exposing the build zone to energy through at least a portion of the cooling device and through at least a portion of the dewetting phase polymerizes the polymerizable liquid to form a solid polymer from the polymerizable liquid, and advancing the adhesive stage away from the build surface to form the three-dimensional object composed of the solid polymer.

4. A method according to claim 2 or 3, wherein the cooling device is optically transparent.

5. An apparatus for forming a three-dimensional object from a polymerizable liquid, comprising: Supports; an adhesive stage operatively associated with the support member, forming an adhesive stage of the three-dimensional object on the support member; a member having a layer of a dewetting phase thereon, the dewetting phase having a build surface, wherein the dewetting phase is not a liquid, wherein the build surface and the adhesive stage define a build zone therebetween; a polymerizable liquid supplier operably associated with the build surface and configured to supply a polymerizable liquid into the build zone for solidification or polymerization; an energy source configured to deliver energy to the building region through the member to form a solid polymer from the polymerizable liquid; At least one controller operably associated with the energy source to deliver energy to the build zone, the at least one controller also operably associated with the adhesive stage for advancing the adhesive stage away from the build surface at a rate dependent on the energy intensity to form the three-dimensional object from the solid polymer.

6. The apparatus of claim 5, wherein the apparatus further comprises an optically transparent cooling device.

7. An apparatus for forming a three-dimensional object from a polymerizable liquid, the apparatus comprising: Supports; an adhesive stage operatively associated with the support member, forming an adhesive stage of the three-dimensional object on the support member; a member having a layer of a dewetting phase thereon, the dewetting phase having a build surface, wherein the build surface and the adhesive stage define a build zone therebetween; Optically transparent cooling devices; a polymerizable liquid supplier operably associated with the build surface and configured to supply a polymerizable liquid into the build zone for solidification or polymerization; an energy source configured to deliver energy to the building region through the member to form a solid polymer from the polymerizable liquid; as well as and at least one controller operably associated with the energy source to deliver energy to the build zone, the at least one controller also operably associated with the cooling device for cooling the build zone, the at least one controller also operably associated with the adhesive bonding stage for advancing the adhesive bonding stage away from the build surface at a rate dependent on energy intensity to form the three-dimensional object from the solid polymer.

8. The apparatus of claim 7, wherein the member is optically transparent.

9. A method of forming a three-dimensional object, comprising: Providing an adhesive stage and a member, the member having a mobile phase thereon, the mobile phase having a building surface, the adhesive stage and the building surface defining a building area therebetween; providing a polymerizable liquid in the build zone, wherein the polymerizable liquid is immiscible with the mobile phase; and The polymerizable liquid is polymerized by exposing the build zone to energy through at least a portion of the mobile phase to form a solid polymer from the polymerizable liquid, and the adhesive stage is advanced away from the build surface to form the three-dimensional object composed of the solid polymer.

10. An apparatus for forming a three-dimensional object from a polymerizable liquid, the apparatus comprising: Supports; an adhesive stage operatively associated with the support member, forming an adhesive stage of the three-dimensional object on the support member; a member having a layer of mobile phase thereon, the mobile phase having a building surface, wherein the building surface and the adhesive stage define a building region therebetween; a polymerizable liquid supplier operably associated with the build surface and configured to supply a polymerizable liquid into the build zone for solidification or polymerization; an energy source configured to deliver energy to the building region through the member to form a solid polymer from the polymerizable liquid; At least one controller operably associated with the energy source to deliver energy to the build zone, the at least one controller also operably associated with the adhesive stage for advancing the adhesive stage away from the build surface at a rate dependent on the energy intensity to form the three-dimensional object from the solid polymer.

Images