Abstract: Techniques are described for consistently moving powder from a hopper into a trough for subsequent delivery into a build area of an additive fabrication system. A powder delivery apparatus may comprise a hopper, a trough, and a doser. The doser may be configured to rotate about an axis and may include a recess that, when the doser is rotated about the axis, travels into and out of the hopper and into and out of the trough. As a result, when powder is present in the hopper, the recess may carry powder from the hopper to the trough when the doser rotates. The trough and doser may be configured so that when the trough contains the desired amount of powder for recoating, the doser does not transfer additional material from the hopper into the trough. As a result, the amount of powder in the trough may be self-regulating.

Abstract: Techniques are described for consistently moving powder from a hopper into a trough for subsequent delivery into a build area of an additive fabrication system. A powder conveyer may be arranged at least partially within the hopper and configured to be actuated to transfer powder to the trough. The powder conveyer may be formed as a screw conveyor, for example. Such techniques do not require complex closed-loop control systems and may be effective irrespective of the flowability of the powder. In at least some cases, there may be no production of excess powder because the amount of powder that is metered into the trough may be precisely controlled to be the amount needed for recoating.

Abstract: Techniques are described for consistently moving powder from a hopper into a trough for subsequent delivery into a build area of an additive fabrication system. A powder delivery apparatus may comprise a hopper, a trough, and a doser. The doser may be configured to rotate about an axis and may include a recess that, when the doser is rotated about the axis, travels into and out of the hopper and into and out of the trough. As a result, when powder is present in the hopper, the recess may carry powder from the hopper to the trough when the doser rotates. The trough and doser may be configured so that when the trough contains the desired amount of powder for recoating, the doser does not transfer additional material from the hopper into the trough. As a result, the amount of powder in the trough may be self-regulating.

Abstract: Techniques are described for tagging source materials for additive fabrication by incorporating a fluorescent and/or phosphorescent taggant into the source material. A light source within an additive fabrication device may direct light onto the source material and a light sensor may detect whether light having appropriate characteristics was produced from the source material through fluorescence and/or phosphorescence. If such light is detected, the additive fabrication device may determine that the source material is from an approved source and thereby has known properties that may be relied upon for fabrication. Otherwise, the additive fabrication device may determine that the source material is from an unapproved source and may take action such as inhibiting fabrication and/or providing a warning to a user.

Abstract: Techniques are described for consistently moving powder from a hopper into a trough for subsequent delivery into a build area of an additive fabrication system. A powder delivery apparatus may comprise a hopper, a trough, and a doser. The doser may be configured to rotate about an axis and may include a recess that, when the doser is rotated about the axis, travels into and out of the hopper and into and out of the trough. As a result, when powder is present in the hopper, the recess may carry powder from the hopper to the trough when the doser rotates. The trough and doser may be configured so that when the trough contains the desired amount of powder for recoating, the doser does not transfer additional material from the hopper into the trough. As a result, the amount of powder in the trough may be self-regulating.

Abstract: Techniques for designing and fabricating thermal support regions via additive fabrication are described. Defects produced as a result of temperature differentials within an additive fabrication device that forms parts by sintering particles of material may be mitigated or avoided by directing energy to regions around a part that is sufficient to heat the material and cause it to partially sinter, but not enough to fully sinter the material. The mechanical properties of such a thermal support region may resist the effects caused by temperature gradients. In addition, or alternatively, the heating of the thermal support region material may reduce heat lost by nearby sintered material. In either or both cases, the thermal support region acts as a kind of ‘volumetric armor’ that surrounds some or all of the part and protects the part from defects.

Abstract: The present disclosure relates to compounds comprising (i) an active agent, wherein the active agent includes a charge at a predetermined pH, (ii) a polymer, wherein the polymer includes an opposite charge than the active agent at the predetermined pH; and (iii) a polyplex comprising the peptide and the polymer electrostatically bond together at the predetermined pH. In some embodiments, the active agent is a peptide, such as a peptide comprising MAPKAP kinase II inhibitory peptide, and in some embodiments the peptide includes a cell-penetrating peptide. In further embodiments, the disclosure provides methods for treating a disease or condition by administering a composition according to the present disclosure to a subject in need thereof.

Abstract: Disclosed herein is a composition comprising a polymer; and a superheated fluid; where at least a portion of the polymer and the superheated fluid co-exist in a single phase. Disclosed herein is a method comprising exposing a polymer to a superheated fluid; swelling at least a portion of the polymer with the superheated fluid so that the polymer and the superheated fluid co-exist in a single phase; and changing pressure or temperature within the single phase to change a property in the polymer.

Abstract: Disclosed herein is an impact modified composition comprising a first polymer; and a second polymer that is dispersed in the first polymer; where the first polymer and the second polymer are melt polymerized in each other's presence, are phase separated from each other after polymerization; are not reactively bonded with each other; and where a precursor to the first polymer and to the second polymer are soluble in one another prior to polymerization. Disclosed herein too is a method comprising melt polymerizing a first monomer and a second monomer in the presence of each other to form a first polymer and a second polymer; where the first monomer and the second monomer are soluble in each other; where first polymer and the second polymer are phase separated from each other with the second polymer being dispersed in the first polymer; where the first polymer and the second polymer are not reactively bonded to each other.

Abstract: Disclosed herein is a composition comprising a polymer; and a superheated fluid; where at least a portion of the polymer and the superheated fluid co-exist in a single phase. Disclosed herein is a method comprising exposing a polymer to a superheated fluid; swelling at least a portion of the polymer with the superheated fluid so that the polymer and the superheated fluid co-exist in a single phase; and changing pressure or temperature within the single phase to change a property in the polymer.

Abstract: The present disclosure relates to compounds comprising (i) an active agent, wherein the active agent includes a charge at a predetermined pH, (ii) a polymer, wherein the polymer includes an opposite charge than the active agent at the predetermined pH; and (iii) a polyplex comprising the peptide and the polymer electrostatically bond together at the predetermined pH. In some embodiments, the active agent is a peptide, such as a peptide comprising MAPKAP kinase II inhibitory peptide, and in some embodiments the peptide includes a cell-penetrating peptide. In further embodiments, the disclosure provides methods for treating a disease or condition by administering a composition according to the present disclosure to a subject in need thereof.