title: Deformation and fracture of echinoderm collagen networks.
abstract: Collagen networks provide the main structural component of most tissues and represent an important ingredient for bio-mimetic materials for bio-medical applications. Here we study the mechanical properties of stiff collagen networks derived from three different echinoderms and show that they exhibit non-linear stiffening followed by brittle fracture. The disordered nature of the network leads to strong sample-to-sample fluctuations in elasticity and fracture strength. We perform numerical simulations of a three dimensional model for the deformation of a cross-linked elastic fibril network which is able to reproduce the macroscopic features of the experimental results and provide insights into the internal mechanics of stiff collagen networks. Our numerical model provides an avenue for the design of collagen membranes with tunable mechanical properties.
authors.affiliation: Department of Applied Physics, Aalto University, P.O. Box 11100, FIN-00076 Aalto, Espoo, Finland.
authors.forename: Markus
authors.initials: M
authors.lastname: Ovaska
authors.affiliation: Institute for Scientific Interchange Foundation, Via Alassio 11/C, 10126 Torino, Italy.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Bertalan
authors.affiliation: Department of Applied Physics, Aalto University, P.O. Box 11100, FIN-00076 Aalto, Espoo, Finland.
authors.forename: Amandine
authors.initials: A
authors.lastname: Miksic
authors.affiliation: Department of Biosciences, University of Milan, via Celoria 26, 20133 Milano, Italy; Center for Complexity and Biosystems, University of Milan, via Celoria 16, 20133 Milano, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Sugni
authors.affiliation: Department of Biosciences, University of Milan, via Celoria 26, 20133 Milano, Italy.
authors.forename: Cristiano
authors.initials: C
authors.lastname: Di Benedetto
authors.affiliation: Department of Biosciences, University of Milan, via Celoria 26, 20133 Milano, Italy.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Ferrario
authors.affiliation: Department of Biosciences, University of Milan, via Celoria 26, 20133 Milano, Italy.
authors.forename: Livio
authors.initials: L
authors.lastname: Leggio
authors.affiliation: Department of Biosciences, University of Milan, via Celoria 26, 20133 Milano, Italy; Center for Complexity and Biosystems, University of Milan, via Celoria 16, 20133 Milano, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Guidetti
authors.affiliation: Department of Applied Physics, Aalto University, P.O. Box 11100, FIN-00076 Aalto, Espoo, Finland.
authors.forename: Mikko J
authors.initials: MJ
authors.lastname: Alava
authors.affiliation: Department of Biosciences, University of Milan, via Celoria 26, 20133 Milano, Italy; Center for Complexity and Biosystems, University of Milan, via Celoria 16, 20133 Milano, Italy. Electronic address: caterina.laporta@unimi.it.
authors.forename: Caterina A M
authors.initials: CAM
authors.lastname: La Porta
authors.affiliation: Center for Complexity and Biosystems, University of Milan, via Celoria 16, 20133 Milano, Italy; Department of Physics, University of Milan, via Celoria 16, 20133 Milano, Italy; Institute for Scientific Interchange Foundation, Via Alassio 11/C, 10126 Torino, Italy; CNR - Consiglio Nazionale delle Ricerche, Istituto per l׳Energetica e le Interfasi, Via R. Cozzi 53, 20125 Milano, Italy; Department of Applied Physics, Aalto University, P.O. Box 11100, FIN-00076 Aalto, Espoo, Finland. Electronic address: stefano.zapperi@unimi.it.
authors.forename: Stefano
authors.initials: S
authors.lastname: Zapperi
mesh_terms: D000818:Animals; D040761:Biomimetic Materials; D003094:Collagen / Q000502:physiology*; D004447:Echinodermata / Q000502:physiology*; D004548:Elasticity; D005109:Extracellular Matrix; D008962:Models, Theoretical; D013314:Stress, Mechanical
chemical_list: D003094:Collagen
keywords: Collagen networks; Computational model; Echinoderms; Elasticity; Fracture