Submitted to A Sinusoidally-Architected Helicoidal Biocomposite N.A. Yaraghi, N. Guarín-Zapata, L.K. Grunenfelder, E. Hintsala, S. Bhowmick, J.M. Hiller, M. Betts, E.L. Principe, Jae-Young Jung, J. McKittrick, R. Wuhrer, P.D. Zavattieri, D. Kisailus Abstract A fibrous herringbone-modified helicoidal architecture is identified within the exocuticle of an impact-resistant crustacean appendage. This previously unreported composite microstructure, which features highly textured apatite mineral templated by an alpha-chitin matrix, provides enhanced stress redistribution and energy absorption over the traditional helicoidal design under compressive loading. Nanoscale toughening mechanisms are also identified using high load nanoindentation and in-situ TEM picoindentation. Keywords: Composites, Toughness, Impact, Biomineral, Ultrastructure DOI: 10.1002/adma.201600786 Graphical Abstract 1 Submitted to DOI: 10.1002/adma.201600786 A Sinusoidally-Architected Helicoidal Biocomposite By Nicholas A. Yaraghi, Nicolás Guarín-Zapata, Lessa K. Grunenfelder, Eric Hintsala, Sanjit Bhowmick, Jon M. Hiller, Mark Betts, Edward L. Principe, Jae-Young Jung, Leigh Sheppard, Richard Wuhrer, Joanna McKittrick, Pablo D. Zavattieri and David Kisailus* * Prof. D. Kisailus, Nicholas A. Yaraghi Materials Science and Engineering Program University of California, Riverside Riverside, CA 92521 (USA) E-mail:
[email protected] Nicolás Guarín-Zapata, Prof. P.D. Zavattieri Lyles School of Civil Engineering Purdue University West Lafayette, IN 47907 (USA) Dr. L.K. Grunenfelder, Prof. D. Kisailus Department of Chemical and Environmental Engineering University of California Riverside, CA 92521 (USA) Dr. E. Hintsala Department of Chemical Engineering and Materials Science University of Minnesota Minneapolis, MN 55455 (USA) Dr. S. Bhowmick Hysitron Inc. Minneapolis, MN 55344 (USA) Jon M.