Influence of Unit‐Cell Geometry on 3D‐Printed Chiral‐Inspired Tubular Metamaterials: Auxeticity and Energy Absorption in Athletic Footwear Applications

Abstract

Lightweight architected metamaterials capable of simultaneously achieving high energy absorption, tailored stiffness, and superior auxetic behavior are increasingly required for advanced engineering applications. However, chiral metamaterials have been studied mainly in planar architectures or relatively simple three‐dimensional configurations, while the coupled effects of geometric parameters on stiffness evolution, energy absorption, and auxeticity in tubular architectures remain insufficiently understood. This study aims to develop and characterize a lightweight chiral‐inspired tubular metamaterial and to systematically investigate the effects of unit‐cell thickness and width on its compressive response. The structures were fabricated by digital light processing (DLP) additive manufacturing and evaluated through quasi‐static compression tests, while validated finite element simulations were employed for the parametric investigation. The proposed architecture exhibits exceptional auxetic behavior, with a Poisson's ratio reaching −3.20, together with tunable strain‐stiffening characteristics. The stiffness improvement ratio reaches 13.32, while the maximum peak force and specific energy absorption are 1755.4 N and 2348 mJ/g, respectively. The numerical model accurately reproduces the experimental response, achieving an R2 of 0.99. The results demonstrate that the proposed tubular architecture enables effective tailoring of stiffness, energy absorption, and auxetic response through geometric design, providing a promising platform for lightweight multifunctional metamaterials.