Jesus Rivera¹, Maryam S. Hosseini², Satoshi Murata³, Allison Pickle¹, Drago Vasile¹, David Restrepo⁴, Atsushi Arakaki³, Pablo D. Zavattieri², David Kisailus¹; ¹University of California Riverside, ²Purdue University, ³Tokyo University of Agriculture and Technology, ⁴University of Texas San Antonio

Nature has evolved efficient strategies, exemplified in the biological tissues of numerous animal and plant species, to synthesize and construct composites that often exhibit exceptional mechanical properties. These biological systems have accomplished this feat by establishing controlled synthesis and hierarchical assembly of nano- to micro-scaled building blocks. One such example is found in the exoskeletal forewings (elytra) of the diabolical iron clad beetle. Lacking the ability to fly away from predators, this desert insect exhibits an extremely impact and crush-resistant elytra via complex and graded interfaces. Here, utilizing advanced microscopy, spectroscopy and in-situ mechanical testing, we reveal previously unreported and critical multiscale architectural designs within the exoskeleton of this impressive beetle, the resulting mechanical response and subsequent toughening mechanisms. These observations are now providing blueprints to multifunctional tough, light-weight impact and crush resistant architected materials.