Auxetic Honeycomb Shoe Sole

thingiverse

***RESIZE BY MEASURING A SIMILARLY SHAPED SOLE*** I made a 3D printable shoe sole from reference photos in Fusion 360. I originally filled the midsole with lattice structures in an attempt to recreate the Adidas Futurecraft sole and that model is called "lattice cushioning." I came across auxetic, or negative Poisson's Ratio structures, that move inward from the sides when force is applied from the top. I found out that the cell structure of thermoplastic polyurethane (the foam in normal shoe soles) is also an auxetic structure that exhibits this behavior, and I immediately 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 is what was missing from the Adidas Futurecraft and my "lattice cushioning" model. When I successfully print this in my Ninjaflex 85 shore hardness TPU, I will test the strength, comfort, and reactivity of this auxetic midsole.