Bio-Inspired Irregular Architected Materials: From Citrus Pericarp to Energy Absorbing Lattices

Irregular architected materials offer a wide design space of mechanical properties such as strength, stiffness, strain-to-failure, and energy absorbed during fracture [1], but their design is a complex challenge. However, biological materials have developed a variety of irregular architectures evolved for impact protection and energy redistribution, such as the citrus fruit pericarp. The irregular structure of the citrus fruit pericarp is composed of a functional lattice-like arrangement of tissue, which protects the ripe fruit upon impact with the ground. In my talk, I will explain how we can examine the morphology of the pericarp lattice to extract general biomimicry design parameters, such as lattice beam density and concavity, which can be used to design lightweight materials with high strength and high strain-to-failure, particularly under dynamic loading. Furthermore, I will describe how computer-aided virtual growth algorithms can be used to design and fabricate lattice samples that mimic the citrus fruit pericarp, with spatially determined density and local coordination. Finally, through both quasi-static and dynamic drop tower testing, I will show how the lattice architecture influences the mechanical performance of the materials, making them optimal candidates for dynamic structural applications in extreme environments.<br/> <br/>[1] T. Magrini, C. Fox, A. Wihardja, A. Kolli & C. Daraio, “Control of Mechanical and Fracture Properties in Two-phase Materials Reinforced by Continuous, Irregular Networks,” arXiv (2023) https://doi.org/10.48550/arXiv.2309.01888