Maryam Hosseini¹, Jesus Rivera², David Restrepo³, David Kisailus², Pablo Zavattieri¹; ¹Purdue University, ²University of California, Riverside, ³Purdue University/University of Texas San Antonio

The focus of this work is to understand the role of the inner architecture in naturally-occuring interlocking interfaces. More specific, we study the abdominal portion of the exoskeleton, consisting of the elytra and ventral cuticle of the diabolical ironclad beetle, a terrestrial beetle that is well known for its high compressive strength, far beyond any other beetle identified to date. The beetle elytra consists of two separated parts connected using dovetail-joints blades and contains a hierarchical assembly of alpha-chitin fibers embedded within a proteinaceous matrix that provides both strength and toughness. We employ a combination of computational models and 3D printing prototypes to study the various competing mechanisms that emerge from the fracture behavior of such joints. In turns, this natural system represents a tough, damage tolerant biological joint that can inspire a new family of architectured materials.