Abstract: According to some aspects, an additive fabrication apparatus is provided configured to form layers of material on a build platform, each layer of material being formed so as to contact a supporting liquid or a film disposed within a container, in addition to the build platform, a liquid photopolymer, and/or a previously formed layer of a material. The additive fabrication apparatus may comprise a container and a leveling element, wherein the leveling element is configured to move across a liquid-liquid interface to promote or create a flat interface between the two liquids. According to some aspects, the additive fabrication comprises a film disposed between two liquids, wherein the film maintains or provides a flat surface at the interface of the two liquids.

Abstract: Techniques for evaluating support for an object to be fabricated via an additive fabrication device are provided. In some embodiments, a three-dimensional representation of the object is obtained and a plurality of voxels corresponding to the representation of the object is generated. A first supportedness value may be assigned to a first voxel of the plurality of voxels based on an amount of support provided by a support structure to the first voxel, and a second supportedness value determined for a second voxel of the plurality of voxels, wherein the second voxel neighbors the first voxel, and wherein the second supportedness value is determined based on the first supportedness value of the first voxel and a weight value representing a transmission rate of supportedness through voxels of the plurality of voxels.

Abstract: A multi-component print surface and associated additive manufacturing methods are generally described.

Abstract: According to some aspects, techniques are described that allow an additive fabrication device to dynamically adjust the size of a post metering volume for adjusting pressure of source material in the volume. These techniques may allow for greater control of material extrusion through an orifice and thereby mitigate or avoid issues of lag time between starting and/or stopping extrusion and/or in which there is unwanted emission of source material through the orifice. In some cases, techniques for adjusting the size of the post metering volume as described herein may include operating an actuator arranged in a channel that is coupled to the post metering volume. In some cases, techniques for adjusting the size of the post metering volume as described herein may include having a stator that is at least partially arranged within a chamber that defines the post metering volume and is free to move within the chamber.

Abstract: Techniques for directing light from a movable stage in an additive fabrication device are provided. According to some aspects, the movable stage may include a parabolic mirror onto which light may be directed at various different incident angles to produce light along different positions along an axis. In some cases, this axis may be perpendicular to a direction of motion of the movable stage.

Abstract: Techniques for force sensing in additive fabrication are provided. According to some aspects, an additive fabrication device may include a force sensor configured to measure a force applied to a build platform during fabrication. A length of time taken for a layer of material to separate from a surface other than the build platform to which it is adhered may be determined based on measurements from the force sensor. Subsequent additive fabrication operations, such as subsequent motion of the build platform, may be adapted based on the determined length of time.

Abstract: According to some aspects, techniques are provided to more accurately produce fine features in additive fabrication. According to some embodiments, the techniques comprise a process that amplifies exposure to edges and thin positive features whilst not substantially affecting negative features. In particular, an area to be cured may be adapted using signal processing techniques to produce an energy density map. The area may subsequently be cured according to the generated energy density map by, for example, adjusting the scan speed, light power and/or number of passes of the light beam according to the map. As a result, the net exposure to edges and thin positive features may be amplified.

Abstract: According to some aspects, a method is provided of removing debris from a liquid photopolymer in an additive fabrication device. According to some embodiments, a mesh of solid material may be formed in an additive fabrication device from a liquid photopolymer, and particles of debris present in the liquid photopolymer may adhere to the mesh. The debris may thereby be removed from the liquid photopolymer by removing the mesh from the additive fabrication device. The mesh may then be discarded.

Abstract: A resin formulation that may be used for additive manufacturing, for example, to provide a water-breakable object is generally described.

Abstract: According to some aspects, techniques are provided to mitigate challenges with additive fabrication devices that utilize a film. These techniques include: improvements to an additive fabrication device build platform to more evenly apply forces onto the film; techniques for inhibiting adhesion between a pair of films and for removing dirt or dust therein; techniques for detecting and/or mitigating the effects of scratches or dust on films; and techniques for detecting film punctures, detecting an imminent film puncture, and/or reducing the impact on the device when punctures occur.

Abstract: According to some aspects, techniques that address one or more drawbacks of laser-based optical systems in additive fabrication devices are described. In some aspects, an additive fabrication device may include one or more variable focus lenses that may be operated (e.g., actuated) during fabrication to adjust the focus, and thereby the spot size, of a laser beam. In some aspects, an additive fabrication device may comprise a laser array, such as a plurality of vertical-cavity surface-emitting lasers (VCSELs), that may be operated to direct light into a build region, rather than using a single laser beam, such as a single diode laser. In some aspects, an additive fabrication device may comprise a container that includes a flexible display film, such as a flexible LCD screen, which may be operated to direct light into the container to thereby cure a liquid photopolymer therein.

Abstract: A multi-component composition for additive manufacturing, and related methods, are generally described.

Abstract: According to some aspects, a method of additive fabrication is provided wherein a plurality of layers are formed on a build platform, each layer contacting a container in addition to the build platform and/or a previously formed layer, the method comprising calculating, using at least one processor, one or more forces to be applied to a first layer of the plurality of layers subsequent to the first layer being formed, said calculating being based at least in part on a determined area of at least one portion of the first layer that overhangs a second layer of the plurality of layers, forming the first layer, the first layer being in contact with the container and in contact with a previously formed layer of the plurality of layers, and separating the first layer from the container by applying the calculated one or more forces to the first layer.

Abstract: According to some aspects, an additive fabrication device is provided configured to form layers of material on a build platform, each layer of material being formed so as to contact a container in addition to the build platform and/or a previously formed layer of material. The additive fabrication device may comprise a container and a wiper, wherein the wiper comprises a wiper arm and a wiper blade coupled to said wiper arm using a pivoting coupling.

Abstract: Techniques for film tensioning in additive fabrication are provided. According to some aspects, a film forming part of a container in an additive fabrication device may be tensioned by different forces along different axes. According to some embodiments, an adjustable tensioning system may be provided within an additive fabrication device that may couple to one or more components of a removable container comprising a film. The tension of the film may be adjusted by the additive fabrication device via the adjustable tensioning system and its coupling to the container.

Abstract: According to some aspects, an additive fabrication apparatus is provided configured to form layers of material on a build platform, each layer of material being formed so as to contact a supporting liquid or a film disposed within a container, in addition to the build platform, a liquid photopolymer, and/or a previously formed layer of a material. The additive fabrication apparatus may comprise a container and a leveling element, wherein the leveling element is configured to move across a liquid-liquid interface to promote or create a flat interface between the two liquids. According to some aspects, the additive fabrication comprises a film disposed between two liquids, wherein the film maintains or provides a flat surface at the interface of the two liquids.

Abstract: Techniques for illuminating a photocurable material within a build area of an additive fabrication device are described. According to some aspects, a light source is provided that can be moved alongside a build area, allowing light to be directed to any desired position within the build area by moving the light source. This configuration may also allow the distance from the light source to the build area to be substantially the same for each position across the build area by moving the light source whilst maintaining a fixed distance from the light source to the build volume. The described approach may allow for fabrication of larger parts in an additive fabrication device by expanding or eliminating the practical upper limit on the area of the build volume that can be imposed by use of a laser light source in such a device.

Abstract: In additive fabrication, less stiff layers generally require a comparatively higher peel force during separation, and that therefore geometric structures that include less stiff layers will also require a comparatively higher peel force during separation. Techniques to lower or otherwise mitigate undesirably large peel forces are described. These techniques include modification to how layers susceptible to a large peel force are formed, modification to a model of a part prior to generating instructions for an additive fabrication device to fabricate the part, and/or improvements to an additive fabrication device hardware.

Abstract: Techniques are described for calibrating an optical system in an additive fabrication device using an image of the build surface within the device. These techniques allow calibration to be performed by imaging one or more calibration features generated on (or at) the build surface, which may include illuminated regions of the build surface, regions of the build surface on which solid material has been formed, and/or regions of the build surface to which energy has otherwise been directed thereby making those regions distinguishable from their surroundings. The calibration features may be produced (at least in part) by the optical system to be calibrated. The location of the calibration features within the image may be compared with the intended location of these calibration features, and corrections to the optical system determined based on any differences between the actual and intended locations.