Abstract: According to some aspects, techniques are provided for identifying contamination in additive fabrication devices by measuring light interacting with the contamination using one or more light sensors. Contamination located between a light source and a target of a light source can affect the uniformity and intensity of the light source when incident upon the target. For instance, in an inverse stereolithography device, contamination located between a light source and a liquid photopolymer resin that is to be cured can affect the quality of the fabricated object when the light is scattered or blocked by the contamination. Identifying the presence of contamination between the light source and the liquid photopolymer resin and alerting the user prior to initiating a fabrication process may increase the quality of the resulting fabricated object and improve the user experience by saving time and photocurable liquid.

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: Techniques for producing a flat film surface in additive fabrication are provided. According to some aspects, a movable stage may be arranged beneath a container having a base that includes a flexible film. The movable stage may include a segmented member in which a number of segments are aligned along a common axis. The segmented member may maintain contact with the flexible film as the movable stage moves beneath the container, with the segmented member producing a flat surface of the flexible film, at least within a region above the movable stage. According to some embodiments, multiple segmented members may be provided within the movable stage, such as in parallel with one another.

Abstract: According to some aspects, techniques are provided for identifying contamination in additive fabrication devices by measuring light interacting with the contamination using one or more light sensors. Contamination located between a light source and a target of a light source can affect the uniformity and intensity of the light source when incident upon the target. For instance, in an inverse stereolithography device, contamination located between a light source and a liquid photopolymer resin that is to be cured can affect the quality of the fabricated object when the light is scattered or blocked by the contamination. Identifying the presence of contamination between the light source and the liquid photopolymer resin and alerting the user prior to initiating a fabrication process may increase the quality of the resulting fabricated object and improve the user experience by saving time and photocurable liquid.

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: According to some aspects, techniques are provided for identifying contamination in additive fabrication devices by measuring light interacting with the contamination using one or more light sensors. Contamination located between a light source and a target of a light source can affect the uniformity and intensity of the light source when incident upon the target. For instance, in an inverse stereolithography device, contamination located between a light source and a liquid photopolymer resin that is to be cured can affect the quality of the fabricated object when the light is scattered or blocked by the contamination. Identifying the presence of contamination between the light source and the liquid photopolymer resin and alerting the user prior to initiating a fabrication process may increase the quality of the resulting fabricated object and improve the user experience by saving time and photocurable liquid.

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: 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: 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 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 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, 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: According to some embodiments, a method of optimizing an additive fabrication process for an object is provided, the method comprising obtaining a representation of an intermediate form of the object, the intermediate form being an expected shape of the object when partially fabricated by the additive fabrication process, simulating one or more forces expected to be applied to the intermediate form of the object during the additive fabrication process, evaluating one or more results of the simulating step against one or more criteria, and adapting the additive fabrication process based at least in part on a result of the evaluating.

Abstract: Multi-film containers for use in additive fabrication devices are provided. According to some aspects, a container may include multiple films that are at least partially detached from one another. In some embodiments, the multiple films may include films formed from different materials. As one example, an upper film may be formed so as to be relatively impermeable to substances within a source material of an additive fabrication device, whereas a lower film may be formed so as to provide desirable mechanical properties. In some cases, the multiple films may be commonly tensioned while being unattached to one another.

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: According to some aspects, techniques are provided for identifying contamination in additive fabrication devices by measuring light interacting with the contamination using one or more light sensors. Contamination located between a light source and a target of a light source can affect the uniformity and intensity of the light source when incident upon the target. For instance, in an inverse stereolithography device, contamination located between a light source and a liquid photopolymer resin that is to be cured can affect the quality of the fabricated object when the light is scattered or blocked by the contamination. Identifying the presence of contamination between the light source and the liquid photopolymer resin and alerting the user prior to initiating a fabrication process may increase the quality of the resulting fabricated object and improve the user experience by saving time and photocurable liquid.

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: According to some embodiments, a method of optimizing an additive fabrication process for an object is provided, the method comprising obtaining a representation of an intermediate form of the object, the intermediate form being an expected shape of the object when partially fabricated by the additive fabrication process, simulating one or more forces expected to be applied to the intermediate form of the object during the additive fabrication process, evaluating one or more results of the simulating step against one or more criteria, and adapting the additive fabrication process based at least in part on a result of the evaluating.

Abstract: Techniques for generating a support structure for an object are provided. In some embodiments, one or more regions of the object are identified as one or more regions to which mechanical support is to be provided and one or more support points within at least a first region of the one or more regions are identified. A support structure may be generated for the object that comprises one or more support tips coupled to the object at the one or more support points, where the support tips being generated based at least in part on a direction normal to the surface of the object at the respective support point. Techniques for providing visual feedback to a user relating to an amount of support that a support structure is expected to provide during fabrication are also provided.