In an example, a method comprises receiving, at a processor, a digital model representing an object to be produced by additive manufacturing. The method may comprise receiving, at the processor, an indication that a first selected region of a surface of the object is to have a first coating applied after printing. The method may further comprise applying a first predefined surface roughness pattern to the first selected region of the surface of the digital model.

A 3D printing apparatus is disclosed herein. The apparatus comprises a container, a build material extraction module, an energy source and a controller. The container is to receive a build volume comprising portions in which an un-cured thermally curable binder has been applied to define a 3D object to be generated and portions on which no binder has been applied. The build material extraction module is to remove part of the build material on which no binder has been applied. The energy source to heat the contents of the container. And the controller is to control the build material extraction module to remove part of the build material on which no binder has been applied; and control the energy source to heat the build material to thermally cure any binder in the container.

A method of manufacturing an optical component having at least one optical function, comprising: —manufacturing using an additive manufacturing process at least part of an optical element (40) by depositing a plurality of pre-determined volume elements (14) of polymerizable material, a part of the optical element (40) being configured to provide at least a part of the optical function of an optical component, said additively manufacturing being performed such that the optical element (40) comprises an unfinished peripheric surface (42), said unfinished peripheric surface (42) having a relief pattern (44) formed by traces of the additive manufacturing process and having at least one depression (18) with regard to another part of the peripheric surface (42), —coating said unfinished peripheric surface (42) with a layer (50) of coating liquid (46) configured to at least partially fill the at least one depression (18).

A system for fabricating an acoustic metamaterial is provided. In an embodiment, a system 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 system also includes an additively manufacturing device configured to form 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 system for fabricating an acoustic metamaterial is provided. In an embodiment, a system 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 system also includes an additively manufacturing device configured to form 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.

Additive-manufacturing systems, surface-processing apparatuses, and methods of forming products using an additive-manufacturing head are provided. In one aspect, an additive-manufacturing system includes an additive-manufacturing head and a surface-processing device coupled to the additive-manufacturing head. In another aspect, a surface-processing apparatus for an additive-manufacturing head includes a housing configured to be coupled to the additive-manufacturing head and a surface-processing device coupled to the housing. In a further aspect, a method of forming a product using an additive-manufacturing head includes forming one or more layers of the product with the additive-manufacturing head and processing at least one of the one or more layers of the product with a surface-processing device coupled to the additive-manufacturing head.

The invention provides a method for manufacturing a 3D item (10), wherein the 3D item (10) comprises an outer layer (210) and a support structure (220) with cavities (230), wherein the outer layer (210) at least partly encloses the support structure (220), and wherein the method comprises: (a) a 3D printing stage comprising 3D printing with fused deposition modeling (FDM) 3D printable material (201) the outer layer (210) and the support structure (220) and at least partly filling the cavities (230) with a filler material (204); and (b) a post-treatment stage comprising post treating at least part of the outer layer (210) for reducing surface roughness.

In example implementations, a method is provided. The method includes printing a three-dimensional (3D) object that includes a secondary structure. The secondary structure is removed. A representation of a surface of the 3D object where the secondary structure was removed is captured. The 3D object is authenticated based on the representation of the surface.

A method for manufacturing a filter medium includes providing a computer-readable three-dimensional model of the filter medium including a plurality of segments, each segment of the three-dimensional model being configured to be converted into a plurality of slices that each define a cross-sectional layer of the filter medium, each segment including an undulating layer extending along a predetermined direction that is different than the predetermined direction of the undulating layer of the other segment; and successively forming each layer of the filter medium by additive manufacturing.

A removable image-capture apparatus (200) comprises an opening (202) intended to receive a calibration plate (10) bearing a reference marking (30) and possibly a test marking (40). The apparatus (200) comprises a source (204) of backlighting visible light situated beneath the opening (202), a sensor (205) for acquiring an image, in the backlighting visible light, of the plate (10), a guiding and supporting device (206) for positioning the sensor (205) above the opening (202) relative to the surround (201), a calculation device (207) configured to analyze the image, recognize the marking (30) and possibly the marking (40) in the image, and calculate aiming-command corrections intended for a firing system firing a powerful incident-radiation beam, which system belongs to an additive manufacturing apparatus, distinct and separate from the apparatus (200).