title: Response of biopolymer networks governed by the physical properties of cross-linking molecules.
abstract: In this study, we examine how the physical properties of cross-linking molecules affect the bulk response of bio-filament networks, an outstanding question in the study of biological gels and the cytoskeleton. We show that the stress-strain relationship of such networks typically undergoes linear increase - strain hardening - stress serration - total fracture transitions due to the interplay between the bending and stretching of individual filaments and the deformation and breakage of cross-linkers. Interestingly, the apparent network modulus is found to scale with the linear and rotational stiffness of the crosslinks to a power exponent of 0.78 and 0.13, respectively. In addition, the network fracture energy will reach its minimum at intermediate rotational compliance values, reflecting the fact that most of the strain energy will be stored in the distorted filaments with rigid cross-linkers while the imposed deformation will be "evenly" distributed among significantly more crosslinking molecules with high rotational compliance.
authors.affiliation: Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China. ylin@hku.hk.
authors.forename: Xi
authors.initials: X
authors.lastname: Wei
authors.affiliation: Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China. ylin@hku.hk.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: Department of Engineering Mechanics, Zhejiang University, Hangzhou, Zhejiang, China. jqian@zju.edu.cn.
authors.forename: Jin
authors.initials: J
authors.lastname: Qian
authors.affiliation: Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China. ylin@hku.hk.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Department of Materials Science and Engineering,, University of Pennsylvania, USA.
authors.forename: V B
authors.initials: VB
authors.lastname: Shenoy
mesh_terms: D001704:Biopolymers / Q000737:chemistry*; D003599:Cytoskeleton / Q000737:chemistry; D020342:Finite Element Analysis; D055595:Mechanical Phenomena; D008958:Models, Molecular; D008968:Molecular Conformation; D013314:Stress, Mechanical; D013696:Temperature
chemical_list: D001704:Biopolymers