A study of the extraordinarily strong and tough silk produced by bagworms

• Published in: Nature communications Vol. 10; no. 1; p. 1469
• Main Authors: Yoshioka, Taiyo, Tsubota, Takuya, Tashiro, Kohji, Jouraku, Akiya, Kameda, Tsunenori
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-04-2019; Nature Publishing Group; Nature Portfolio
• Subjects: 45/91; 631/208/514/2008; 631/45/535/1261; 631/601/1466; 639/301/1023/303; 639/301/54/1754; Animals; Biomechanical Phenomena; Deformation; Elastic deformation; Elastic properties; Elasticity; Fibers; Humanities and Social Sciences; Japan; Larvae; Lepidoptera; Materials Testing; Moths; multidisciplinary; Proteins; Science; Science (multidisciplinary); Sericins - metabolism; Sericins - ultrastructure; Silk; Silk - physiology; Silk - ultrastructure; Stress, Mechanical; Structural damage; Structural hierarchy; Synchrotrons; Tensile deformation; Tensile Strength; Weight; X-Rays; Japan
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-09350-3

Global ecological damage has heightened the demand for silk as ‘a structural material made from sustainable resources’. Scientists have earnestly searched for stronger and tougher silks. Bagworm silk might be a promising candidate considering its superior capacity to dangle a heavy weight, summed up by the weights of the larva and its house. However, detailed mechanical and structural studies on bagworm silks have been lacking. Herein, we show the superior potential of the silk produced by Japan’s largest bagworm,
Eumeta variegata
. This bagworm silk is extraordinarily strong and tough, and its tensile deformation behaviour is quite elastic. The outstanding mechanical property is the result of a highly ordered hierarchical structure, which remains unchanged until fracture. Our findings demonstrate how the hierarchical structure of silk proteins plays an important role in the mechanical property of silk fibres.
Spider silk is widely studied for its structural properties; however, other creatures produce silk that could be of interest. Here, the authors study the properties and structure of Bagworm silk and report it as being extraordinarily strong and tough compared to other known silks.