A three-dimensional auxetic structure, comprising a plurality of adjoining hollow cells, each hollow cell having cell walls and a transversal cross section of the plurality hollow cells following a two-dimensional auxetic pattern, each cell wall comprising folding lines parallel to a plane containing the auxetic pattern such that peaks and valleys are defined in the cell walls and the cell walls being foldable along the folding lines.

A three-dimensional auxetic structure, comprising a plurality of adjoining hollow cells, each hollow cell having cell walls and a transversal cross section of the plurality hollow cells following a two-dimensional auxetic pattern, each cell wall comprising folding lines parallel to a plane containing the auxetic pattern such that peaks and valleys are defined in the cell walls and the cell walls being foldable along the folding lines.

Methods of creating a hook for a bike rack. The methods include the steps of providing a planar metal material, cutting a two-dimensional shape from the planar metal material where the two-dimensional shape defines a hook precursor, forming the hook precursor into a three-dimensional hook where the three-dimensional hook includes a hook face, and adding a protective layer to the hook face. In some examples, the methods include processing the three dimensional hook to remove sharp edges, cutting a mounting point into the hook precursor, cutting a bevel on an edge of the hook precursor to define a beveled edge, and/or cutting a curve on an edge of the hook precursor to define a rounded edge.

Methods of creating a hook for a bike rack. The methods include the steps of providing a planar metal material, cutting a two-dimensional shape from the planar metal material where the two-dimensional shape defines a hook precursor, forming the hook precursor into a three-dimensional hook where the three-dimensional hook includes a hook face, and adding a protective layer to the hook face. In some examples, the methods include processing the three dimensional hook to remove sharp edges, cutting a mounting point into the hook precursor, cutting a bevel on an edge of the hook precursor to define a beveled edge, and/or cutting a curve on an edge of the hook precursor to define a rounded edge.

A method of manufacturing a multi-sided or otherwise relatively three-dimensional formed structure for, e.g., an aerospace vehicle. A relatively planar base structure is constructed using a first construction technique. Features (e.g., ribs) are incorporated into the base structure using a second construction technique (e.g., additive or subtractive manufacturing) to create an intermediate structure. The intermediate structure is folded along fold-lines or otherwise physically formed to create the formed structure, such that some of the features are located within an internal space defined by the formed structure. Joints between the sides of the formed structure are welded, fastened, or otherwise secured. Separately constructed additional elements (e.g., bulkheads) may be incorporated into the structure. A closeout element may be added to the formed structure to further define and close the internal space. Throughout the process, the structures, features, and elements may be refined to desired tolerances.

A method of manufacturing a multi-sided or otherwise relatively three-dimensional formed structure for, e.g., an aerospace vehicle. A relatively planar base structure is constructed using a first construction technique. Features (e.g., ribs) are incorporated into the base structure using a second construction technique (e.g., additive or subtractive manufacturing) to create an intermediate structure. The intermediate structure is folded along fold-lines or otherwise physically formed to create the formed structure, such that some of the features are located within an internal space defined by the formed structure. Joints between the sides of the formed structure are welded, fastened, or otherwise secured. Separately constructed additional elements (e.g., bulkheads) may be incorporated into the structure. A closeout element may be added to the formed structure to further define and close the internal space. Throughout the process, the structures, features, and elements may be refined to desired tolerances.

A method of forming an ice resistant surface includes determining, based at least in part on a desired pattern of frost formation, a vertex angle for a ridge that is to be formed on a substrate. The method also includes determining, based at least in part on the desired pattern of frost formation, a vertex height for the ridge that is to be formed on the substrate. The method further includes forming a plurality of ridges on the substrate, where each ridge in the plurality of ridges has the vertex angle and the vertex height.

A method of forming an ice resistant surface includes determining, based at least in part on a desired pattern of frost formation, a vertex angle for a ridge that is to be formed on a substrate. The method also includes determining, based at least in part on the desired pattern of frost formation, a vertex height for the ridge that is to be formed on the substrate. The method further includes forming a plurality of ridges on the substrate, where each ridge in the plurality of ridges has the vertex angle and the vertex height.

A battery manufacturing device for manufacturing a cylindrical battery by folding a positive electrode tab connected to a top cap includes a jig that makes a pendulum swing and presses a positive electrode tab; an adjusting member that forms a turning radius of the pendulum swing; and a folding knife that presses a folding part of the positive electrode tab. A method of using the battery manufacturing device is also provided.

An apparatus and method are disclosed for the automated manufacture of a duct flange profile to make small duct fittings, including a transverse duct flange duct flange profile. The duct flange profile is directed to small part duct fittings with section widths up to about 16 inches in 20 to 26 gauge metal. The apparatus includes a bending head assembly having a drive roller, a pressure roller, an anvil and a bending leaf and a roll form assembly.