title: Tightening slip knots in raw and degummed silk to increase toughness without losing strength.
abstract: Knots are fascinating topological elements, which can be found in both natural and artificial systems. While in most of the cases, knots cannot be loosened without breaking the strand where they are tightened, herein, attention is focused on slip or running knots, which on the contrary can be unfastened without compromising the structural integrity of their hosting material. Two different topologies are considered, involving opposite unfastening mechanisms, and their influence on the mechanical properties of natural fibers, as silkworm silk raw and degummed single fibers, is investigated and quantified. Slip knots with optimized shape and size result in a significant enhancement of fibers energy dissipation capability, up to 300-400%, without affecting their load bearing capacity.
authors: Laboratory of Bio-inspired &Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, 38123 Trento, Italy.
authors: Maria F
authors: MF
authors: Pantano
authors: Laboratory of Bio-inspired &Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, 38123 Trento, Italy.
authors: Alice
authors: A
authors: Berardo
authors: Laboratory of Bio-inspired &Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, 38123 Trento, Italy.|Center for Materials and Microsystems, Fondazione Bruno Kessler, Via Sommarive 18, 38123 Povo (TN), Italy.|School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, U.K.
authors: Nicola M
authors: NM
authors: Pugno
mesh_terms: D000818:Animals; D055119:Elastic Modulus; D008968:Molecular Conformation; D047011:Silk / Q000737:chemistry*; D013314:Stress, Mechanical; D013718:Tensile Strength
chemical_list: D047011:Silk