The impact attenuation behavior of three-dimensional soft elastomeric lattices

Abstract

• A series of reusable impact-isolation soft lattice structures are designed. • Predictive models for different cellular unit cells are established. • The impact isolation behaviors of soft lattices are experimentally verified. Cellular structures, distinguished by their porous characteristics, are frequently adopted in designs aimed at impact isolation, owing to their lightweight attributes and exceptional ability to absorb energy during impact events. Lattice structures often rely on plastic deformation to absorb energy. However, in applications such as sports protection and robotic grasping, there exists a requirement for a reusable structure designed to isolate impacts, which can be effectively achieved by three-dimensional flexible lattice structures. In this work, a theoretical calculation method for soft lattice structures is proposed, and in light of this method, a three-dimensional soft lattice structure aimed at isolating impacts has been carefully designed. The predictive theory for the quasistatic mechanical properties, including stiffness and buckling strength for three-dimensional soft lattice structures is described. On the basis of the quasizero stiffness characteristics inherent in body-centered cubic, octahedral, and regular diamond structures, a soft impact isolation structure is designed. The soft structure, fabricated with thermoplastic polyurethane material, demonstrated a peak impact isolation efficiency of 83%, despite possessing a thickness of 24 mm described. The work provides a novel design methodology for three-dimensional soft lattice structures and supports the development of reusable impact isolation structures for applications such as reconfigurable robots and space capture missions.