title: In-drop capillary spooling of spider capture thread inspires hybrid fibers with mixed solid-liquid mechanical properties.
abstract: An essential element in the web-trap architecture, the capture silk spun by ecribellate orb spiders consists of glue droplets sitting astride a silk filament. Mechanically this thread presents a mixed solid-liquid behavior unknown to date. Under extension, capture silk behaves as a particularly stretchy solid, owing to its molecular nanosprings, but it totally switches behavior in compression to now become liquid-like: It shrinks with no apparent limit while exerting a constant tension. Here, we unravel the physics underpinning the unique behavior of this "liquid wire" and demonstrate that its mechanical response originates in the shape-switching of the silk filament induced by buckling within the droplets. Learning from this natural example of geometry and mechanics, we manufactured programmable liquid wires that present previously unidentified pathways for the design of new hybrid solid-liquid materials.
authors.affiliation: Institut Jean Le Rond d'Alembert, Unité Mixte de Recherche 7190, Centre National de la Recherche Scientifique and Université Pierre et Marie Curie, Sorbonne Universités, F-75005 Paris, France;
authors.forename: Hervé
authors.initials: H
authors.lastname: Elettro
authors.affiliation: Institut Jean Le Rond d'Alembert, Unité Mixte de Recherche 7190, Centre National de la Recherche Scientifique and Université Pierre et Marie Curie, Sorbonne Universités, F-75005 Paris, France;
authors.forename: Sébastien
authors.initials: S
authors.lastname: Neukirch
authors.affiliation: Oxford Silk Group, Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom.
authors.forename: Fritz
authors.initials: F
authors.lastname: Vollrath
authors.affiliation: Institut Jean Le Rond d'Alembert, Unité Mixte de Recherche 7190, Centre National de la Recherche Scientifique and Université Pierre et Marie Curie, Sorbonne Universités, F-75005 Paris, France; arnaud.antkowiak@upmc.fr.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Antkowiak
mesh_terms: D000269:Adhesives / Q000737:chemistry*; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001696:Biomechanical Phenomena; D008422:Materials Testing; D008962:Models, Theoretical; D047011:Silk / Q000737:chemistry / Q000502:physiology*; D012984:Software; D012996:Solutions; D013112:Spiders / Q000502:physiology*; D013718:Tensile Strength
chemical_list: D000269:Adhesives; D001672:Biocompatible Materials; D047011:Silk; D012996:Solutions
keywords: bioinspired material; elastocapillarity; fluid–structure interaction; microsystems; spider silk