Auxetic Honeycomb Shoe Sole

thingiverse

I measure a similarly shaped sole to resize by myself. A 3D printable shoe sole was created from reference photos in Fusion 360 by me. Originally, the midsole was filled with lattice structures to recreate the Adidas Futurecraft sole, and that model is called "lattice cushioning." I came across auxetic structures, or negative Poisson's Ratio, which move inward from the sides when force is applied from above. The cell structure of thermoplastic polyurethane (the foam in normal shoe soles) is also an auxetic structure that exhibits this behavior. Therefore, I concluded that the resistance from all dimensions of the structure compressing inwards in sync must change the resistance more rapidly, thus causing a more bouncy feeling. This bouncy feeling was missing from the Adidas Futurecraft and my "lattice cushioning" model. When I successfully print this auxetic midsole in Ninjaflex 85 shore hardness TPU, I will test its strength, comfort, and reactivity.