A method, system, and apparatus for fabricating an acoustic metamaterial is provided. In an embodiment, a method for fabricating an acoustic metamaterial includes determining at least one tuned physical property for each of a plurality of micro-resonators according to a desired acoustic property of the acoustic metamaterial. For a particular physical property, a value of the tuned physical property for at least one of the plurality of micro-resonators is different from a value of the tuned physical property for at least one other of the plurality of micro-resonators. The method also includes additively forming the acoustic metamaterial such that the acoustic metamaterial comprises a first structure and the plurality of micro-resonators embedded within the first structure. Forming the acoustic metamaterial is performed such that an actual physical property of each of the plurality of micro-resonators is equal to a corresponding tuned physical property for each of the plurality of micro-resonators.

A method, system, and apparatus for fabricating an acoustic metamaterial is provided. In an embodiment, a method for fabricating an acoustic metamaterial includes determining at least one tuned physical property for each of a plurality of micro-resonators according to a desired acoustic property of the acoustic metamaterial. For a particular physical property, a value of the tuned physical property for at least one of the plurality of micro-resonators is different from a value of the tuned physical property for at least one other of the plurality of micro-resonators. The method also includes additively forming the acoustic metamaterial such that the acoustic metamaterial comprises a first structure and the plurality of micro-resonators embedded within the first structure. Forming the acoustic metamaterial is performed such that an actual physical property of each of the plurality of micro-resonators is equal to a corresponding tuned physical property for each of the plurality of micro-resonators.

A method of making a foamed article comprises (a) injection molding a molten thermoplastic elastomer to form an precursor; (b) crosslinking the thermoplastic elastomer; (c) heating the thermoplastic elastomer to a first temperature to soften the thermoplastic elastomer; (d) infusing the thermoplastic elastomer with at least one inert gas at a first pressure that is sufficient to cause the at least one inert gas to permeate into the softened thermoplastic elastomer; and (e) while the article is softened, reducing the pressure to a second pressure below the first pressure to at least partially foam the precursor into a foamed article, wherein the foamed article is substantially the same shape as the precursor.

A method of making a foamed article comprises (a) injection molding a molten thermoplastic elastomer to form an precursor; (b) crosslinking the thermoplastic elastomer; (c) heating the thermoplastic elastomer to a first temperature to soften the thermoplastic elastomer; (d) infusing the thermoplastic elastomer with at least one inert gas at a first pressure that is sufficient to cause the at least one inert gas to permeate into the softened thermoplastic elastomer; and (e) while the article is softened, reducing the pressure to a second pressure below the first pressure to at least partially foam the precursor into a foamed article, wherein the foamed article is substantially the same shape as the precursor.

A process for producing an article by three-dimensional printing includes applying a 1,1-di-activated vinyl compound-containing liquid binder over a predetermined area of a layer of solid particles. The liquid binder infiltrates gaps between the solid particles to form a first cross-sectional layer of an article, and the 1,1-di-activated vinyl compound reacts to solidify the liquid binder and bind the solid particles in the first cross-sectional layer of the article. Also provided is an article produced by the three-dimensional printing process, set forth herein.

A process for producing an article by three-dimensional printing includes applying a 1,1-di-activated vinyl compound-containing liquid binder over a predetermined area of a layer of solid particles. The liquid binder infiltrates gaps between the solid particles to form a first cross-sectional layer of an article, and the 1,1-di-activated vinyl compound reacts to solidify the liquid binder and bind the solid particles in the first cross-sectional layer of the article. Also provided is an article produced by the three-dimensional printing process, set forth herein.

An additive manufacturing machine (910) includes a build platform (908) extending within a horizontal plane (H) and a gantry (930) positioned above the build platform (908) and defining a build area (932). A build unit (920) includes a powder dispenser (906) for discharging a layer of additive powder (902) and an energy source (922) for selectively directing energy toward the layer of additive powder (902) to fuse portions of the layer of additive powder (902). The gantry (930) movably supports the build unit (920) within the build area and a powder supply system (900) is positioned below the gantry (930) and extends between a powder supply source (940) and the powder dispenser (906).

The present disclosure relates to a build material for 3D printing. The build material comprises polymeric particles comprising polypropylene and at least one elastomer. The polymeric particles comprise a surface-active coating.

The present disclosure relates to a build material for 3D printing. The build material comprises polymeric particles comprising polypropylene and at least one elastomer. The polymeric particles comprise a surface-active coating.

To identify and/or assess structural integrity of a composite material comprising fiduciary markers which attenuate x-rays to an extent greater than the rest of the material, a method is provided wherein x-ray 3D tomosynthesis images of the composite material are created using an array of x-ray emitters and a digital x-ray detector wherein the array of x-ray emitters and the digital x-ray detector are maintained in fixed relation to one another and to the composite material, the 3D tomosynthesis images being used to determine the relative location of at least some of the fiduciary markers with respect to one another; a database is provided for storing the relative location of at least some of the fiduciary markers with respect to one another, further x-ray 3D tomosynthesis images of the same, or a different, composite material may be checked against the data in the database to ascertain structural integrity and/or identity of the material.