Abstract: 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.

Abstract: A deformable auxetic structure for absorbing energy of an impact that comprises a plurality of interconnected adjoining tridimensional auxetic cells where each tridimensional auxetic cell comprises at least one surface element and a plurality of legs extending from the surface, the plurality of legs and the surface element being configured such that the sectional cut of the structure in at least two planes perpendicular to the surface element follows an auxetic pattern.

Abstract: A modular mold for producing a panel including a panel of fiber reinforced material. The panel is configured to form hollow cells having an undulated trapezoidal cross-section. The mold includes at least three molding bars for forming each hollow cell. One of the molding bars has a trapezoidal cross shape. The other two molding bars have a triangular cross shape. The trapezoidal molding bar is located between the two triangular molding bars. The three molding bars when put together its cross-section forms the shape of the trapezoidal cross-section of the hollow cell.

Abstract: A deformable auxetic structure for absorbing energy of an impact that comprises a plurality of interconnected adjoining tridimensional auxetic cells where each tridimensional auxetic cell comprises at least one surface element and a plurality of legs extending from the surface, the plurality of legs and the surface element being configured such that the sectional cut of the structure in at least two planes perpendicular to the surface element follows an auxetic pattern.

Abstract: A modular mold for producing a panel including a panel of fiber reinforced material. The panel is configured to form hollow cells having an undulated trapezoidal cross-section. The mold includes at least three molding bars for forming each hollow cell. One of the molding bars has a trapezoidal cross shape. The other two molding bars have a triangular cross shape. The trapezoidal molding bar is located between the two triangular molding bars. The three molding bars when put together its cross-section forms the shape of the trapezoidal cross-section of the hollow cell.

Abstract: 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.