US Patent 9402439 Auxetic structures and footwear with soles having auxetic structures

A material that includes at least one layer made of an auxetic structure and articles of footwear having soles comprising the materials. When the material is under tension, it expands in both the direction under tension and in the directional orthogonal to the direction under tension. The articles of footwear have soles that have at least one layer made of a material that has a pattern of geometrical patterns with polygonal apertures. The geometrical patterns have hinged polygons that rotate with respect to each other when the sole is under lateral or longitudinal tension, thus increasing the lateral and longitudinal dimensions of the sole.