Spider silk as a novel high performance biomimetic muscle driven by humidity

• DOI: 10.1242/jeb.028282
• Publication Date: 2009-06-12T19:08:59Z
• Authors: Ingi Agnarsson; Ali Dhinojwala; Vasav Sahni; Todd A. Blackledge
• Keywords: Spider Silk

The abrupt halt of a bumble bee's flight when it impacts the almost invisible threads an orb web provides elegant example amazing strength and toughness spider silk. Spiders depend upon these properties for survival, yet impressive performance silk is not limited solely to tensile mechanics. Here, we show that also exhibits powerful cyclic contractions, allowing act as high mimic biological muscles. These contractions are actuated by changes in humidity alone repeatedly generate work 50 times greater than equivalent mass human muscle. Although demonstrate this response general occurs weakly diverse hydrophilic materials, modulus such generates exceptional force. Furthermore, because effect already operates at level single fibers, only 5 microm diameter, can easily be scaled across entire size range which muscles operate. By contrast, most successful synthetic developed so far driven electric voltage, they cannot scale large ranges cross-sectional areas. potential applicability further enhanced our finding silkworm fibers exhibit contraction available commercial quantities. simplicity using wet or dry air drive biomimetic muscle incredible power generated offer unique possibilities designing lightweight compact actuators robots micro-machines, new sensors, green energy production.