Sean Garner¹, Steven Naleway², Maryam Hosseini³, Claire Acevedo², Eric Schaible ⁴, Bernd Gludovatz⁵, Jae-Young Jung¹, Joanna M McKittrick¹, Pablo Zavattieri³; ¹Univ of California San Diego, ²University of Utah, ³Purdue University, ⁴Lawrence Berkeley National Laboratory, ⁵University of New South Wales

This research explores the structure and mechanical properties of the collagen found in the dermal armor of the boxfish (Lactoria cornuta). Microcomputed tomography revealed a 3D image of the dermal armor’s complex collagen structure. Helical interfibrillar gaps in the collagen base were found that suggest the collagen in the boxfish is a Bouligand-type structure. In-situ scanning electron microscopy (SEM) tests were performed between two connected scutes and indicate that the interfacial collagen is structurally designed to absorb energy to protect the internal collagen. In-situ small-angle X-ray scattering also corroborated the complex collagen structure. These results are coupled with finite element simulations that characterize the interfacial collagen and validate the non-linear deformation response seen in the in-situ SEM. These findings provide a novel basis to synthesize impact-resistant bioinspired composites. This work is supported by the Multi-University Research Initiative through the Air Force Office of Scientific Research (AFOSR-FA9550-15-1-0009)