Abstract: The present disclosure provides methods for generating three-dimensional (3D) objects. The methods may comprise generating a green part corresponding to the 3D object. The green part may comprise a plurality of particles and reactants for conducting a self-propagating reaction. The reactants may be used to conduct a self-propagating reaction that generates heat sufficient to de-bind or pre-sinter the green part. External heat may be supplied to the green part to sinter the plurality of particles, thereby yielding the 3D object. The disclosure also provides methods for generating a 3D object using a resin. The methods may comprise using the resin to generate a green part, heating the green part at a first temperature to decompose a binder in the green part, heating the green part at a second temperature to decompose a polymeric material in the green part, and sintering the green part to yield the 3D object.

Abstract: Methods, systems, and apparatus, including a method of multi-material stereolithographic three dimensional printing comprising, depositing a first material through a first material dispenser of a stereolithographic three dimensional printer onto an optical exposure window to form a first material layer; curing the first material layer to form a first material structure on a build head of the stereolithographic three dimensional printer; depositing a second material through the first material dispenser or a second material dispenser onto the optical exposure window to form a second material layer; and curing the second material layer to form a second material structure on the build head.

Abstract: The present disclosure provides compositions and methods for printing three-dimensional (3D) objects. A composition for 3D printing may comprise a polymeric precursor configured to form a polymeric material, wherein the polymeric material is configured to decompose at a first temperature. The composition may further comprise a photoinitiator configured to initiate formation of the polymeric material from the polymeric precursor when exposed to photoradiation. The composition may further comprise a plurality of particles comprising a first metal. The composition may further comprise a soluble metallic precursor compound configured to react at a second temperature to form a plurality of nanoparticles comprising a second metal capable of alloying with the first metal.

Abstract: The present disclosure provides method and systems for printing a three-dimensional (3D) object. A method for 3D printing may comprise providing a mixture comprising (i) a polymeric precursor, (ii) a photoinitiator configured to initiate formation of a polymeric material from the polymeric precursor, and (iii) a photoinhibitor configured to inhibit the formation of the polymeric precursor. The method may comprise exposing the mixture to (i) a first light to cause the photoinitiator to initiate formation of the polymeric material, thereby to print the 3D object, and (ii) a second light to cause the photoinhibitor to inhibit the formation of the polymeric material. During printing of the 3D object, a ratio of (i) an energy of the second light sufficient to initiate formation of the polymeric material relative to (ii) an energy of the first light sufficient to initiate formation of the polymeric material may be greater than 1.

Abstract: The present disclosure provides methods and systems for printing a three-dimensional (3D) object. The methods may comprise providing, adjacent to a build surface, a film comprising a polymeric precursor. A sensor may be used to determine a profile of the film. The profile may be indicative of a quality of the film. If the profile meets a quality threshold, at least a portion of the film may be exposed to light to initiate formation of a polymeric material from the polymeric precursor, thereby printing at least a portion of the 3D object.

Abstract: The present disclosure provides a system for printing a three-dimensional object. The system may comprise an open platform configured to hold a film of a viscous liquid comprising a photoactive resin. The open platform may comprise a print window. The system may comprise a deposition head comprising a nozzle in fluid communication with a source of the viscous liquid. The deposition head may be configured to move across the platform and deposit the film over the print window. The system may use multiple viscous liquids. The system may comprise an optical source that provides light through the print window for curing at least a portion of the film of the viscous liquid. The system may comprise a controller operatively coupled to direct movement of the deposition head and projection of the light, thereby printing at least a portion of the 3D object.

Abstract: Methods, systems, and apparatus, including a method of multi-material stereolithographic three dimensional printing comprising, depositing a first material through a first material dispenser of a stereolithographic three dimensional printer onto an optical exposure window to form a first material layer; curing the first material layer to form a first material structure on a build head of the stereolithographic three dimensional printer; depositing a second material through the first material dispenser or a second material dispenser onto the optical exposure window to form a second material layer; and curing the second material layer to form a second material structure on the build head.

Abstract: The present disclosure provides methods, systems, and apparatuses relating to hardware configurations for performing multi-wavelength three dimensional (3D) printing using photoinhibition. In at least one aspect, a system for 3D printing comprises a reservoir capable of holding a liquid including a photoactive resin, a build head that undergoes relative motion within the reservoir during 3D printing of a 3D object on the build head, a light projection device that projects a photoinitiation light beam at a first wavelength into a build area within the liquid, and a plurality of light sources arranged with respect to the light projection device and the reservoir that project a plurality of photoinhibiting light beams into the build area at a second wavelength. Each of the plurality of photoinhibition light beams may be projected at a peak intensity in a different respective position in the build area.

Abstract: The present disclosure provides a system for printing a three-dimensional object. The system may comprise an open platform configured to hold a film of a viscous liquid comprising a photoactive resin. The open platform may comprise a print window. The system may comprise a deposition head comprising a nozzle in fluid communication with a source of the viscous liquid. The deposition head may be configured to move across the platform and deposit the film over the print window. The system may use multiple viscous liquids. The system may comprise an optical source that provides light through the print window for curing at least a portion of the film of the viscous liquid. The system may comprise a controller operatively coupled to direct movement of the deposition head and projection of the light, thereby printing at least a portion of the 3D object.

Abstract: Techniques and systems for enhancing vertical edges during photopolymer-based three-dimensional (3D) printing are described.

Abstract: Techniques and systems for 3D printing using mirrors that are oriented at about 45 degrees from an X-axis and Y-axis are described. A technique includes receiving an object model; rotating the object model about 45 degrees around the Z-axis; generating cross-sectional images of the rotated object model; mapping pixels of the cross-sectional images to corresponding mirrors of a digital micromirror device of an additive manufacturing apparatus to form additive-manufacturing images, wherein edges of the mirrors are oriented about 45 degrees from the X-axis of the digital micromirror device and about 45 degrees from the Y-axis of the digital micromirror; and providing the additive manufacturing images to generate a build piece corresponding to the object model. Other implementations can include corresponding systems, apparatus, and computer program products.

Abstract: The present disclosure provides a system for printing a three-dimensional object. The system may comprise an open platform configured to hold a film of a viscous liquid comprising a photoactive resin. The open platform may comprise a print window. The system may comprise a deposition head comprising a nozzle in fluid communication with a source of the viscous liquid. The deposition head may be configured to move across the platform and deposit the film over the print window. The system may use multiple viscous liquids. The system may comprise an optical source that provides light through the print window for curing at least a portion of the film of the viscous liquid. The system may comprise a controller operatively coupled to direct movement of the deposition head and projection of the light, thereby printing at least a portion of the 3D object.

Abstract: The present disclosure provides a system for printing a three-dimensional object. The system may comprise an open platform configured to hold a film of a viscous liquid comprising a photoactive resin. The open platform may comprise a print window. The system may comprise a deposition head comprising a nozzle in fluid communication with a source of the viscous liquid. The deposition head may be configured to move across the platform and deposit the film over the print window. The system may use multiple viscous liquids. The system may comprise an optical source that provides light through the print window for curing at least a portion of the film of the viscous liquid. The system may comprise a controller operatively coupled to direct movement of the deposition head and projection of the light, thereby printing at least a portion of the 3D object.

Abstract: Techniques and systems for sub-pixel grayscale three-dimensional (3D) printing are described. A technique includes mapping a 3D digital model onto a 3D grid of voxels associated with a 3D printer; assigning a first intensity level to first voxels that are fully contained within the model, the first intensity level being sufficient to cure photoactive resin during a curing time; determining, based on geometric information provided by the model, containment degrees for second voxels that are partially contained within the model; assigning second intensity levels to the second voxels based respectively on the containment degrees, the second intensity levels being greater than a third intensity level and lesser than the first intensity level; assigning the third intensity level to third voxels that are outside of the model; and generating one or more graphic files based on the first, second, third voxels, and respectively assigned intensity levels.

Abstract: Techniques and systems for 3D printing using mirrors that are oriented at about 45 degrees from an X-axis and Y-axis are described. A technique includes receiving an object model; rotating the object model about 45 degrees around the Z-axis; generating cross-sectional images of the rotated object model; mapping pixels of the cross-sectional images to corresponding mirrors of a digital micromirror device of an additive manufacturing apparatus to form additive-manufacturing images, wherein edges of the mirrors are oriented about 45 degrees from the X-axis of the digital micromirror device and about 45 degrees from the Y-axis of the digital micromirror; and providing the additive manufacturing images to generate a build piece corresponding to the object model. Other implementations can include corresponding systems, apparatus, and computer program products.

Abstract: The present disclosure provides method and systems for printing a three-dimensional (3D) object. A method for 3D printing may comprise providing a mixture comprising (i) a polymeric precursor, (ii) a photoinitiator configured to initiate formation of a polymeric material from the polymeric precursor, and (iii) a photoinhibitor configured to inhibit the formation of the polymeric precursor. The method may comprise exposing the mixture to (i) a first light to cause the photoinitiator to initiate formation of the polymeric material, thereby to print the 3D object, and (ii) a second light to cause the photoinhibitor to inhibit the formation of the polymeric material. During printing of the 3D object, a ratio of (i) an energy of the second light sufficient to initiate formation of the polymeric material relative to (ii) an energy of the first light sufficient to initiate formation of the polymeric material may be greater than 1.

Abstract: Methods, systems, and apparatus, including medium-encoded computer program products, for three dimensional print adhesion reduction using photoinhibition include, in one aspect, a method including: moving a build plate in a vat of liquid including a photoactive resin; creating a photoinhibition layer within the liquid directly adjacent a window of the vat by directing a first light through the window into the liquid, the first light having a first wavelength selected to produce photoinhibition; and creating a solid structure on the build plate from the photoactive resin within a photoinitiation layer of the liquid by directing a second light through the window into the liquid, where the photoinitiation layer resides between the photoinhibition layer and the build plate, and the second light has a second wavelength different than the first wavelength.

Abstract: Methods, systems, and apparatus, including medium-encoded computer program products, for three dimensional print adhesion reduction using photoinhibition include, in one aspect, a method including: moving a build plate in a vat of liquid including a photoactive resin; creating a photoinhibition layer within the liquid directly adjacent a window of the vat by directing a first light through the window into the liquid, the first light having a first wavelength selected to produce photoinhibition; and creating a solid structure on the build plate from the photoactive resin within a photoinitiation layer of the liquid by directing a second light through the window into the liquid, where the photoinitiation layer resides between the photoinhibition layer and the build plate, and the second light has a second wavelength different than the first wavelength.

Abstract: An apparatus for bottom-up fabrication of three dimensional objects, the apparatus comprising: a vat for a photosensitive polymer, the floor of the vat including a working surface arranged such that, in use, light incident on the working surface interacts with the photosensitive polymer at the working surface to fabricate a portion of the three dimensional object; a build platform capable of being inserted into the vat, the build platform having a planar surface; an elevator mechanism capable of adjusting the separation between the working surface of the vat and the planar surface of the build platform; and a rotation mechanism capable of varying the relative rotational position of the vat relative to the build platform, the relative rotation being about an axis which is normal to the working surface of the vat.