Adhesion modulation using glue droplet spreading in spider capture silk. Issue 130 (31st May 2017)

• Record Type: Journal Article
• Authors: Amarpuri, Gaurav; Zhang, Ci; Blackledge, Todd A.; Dhinojwala, Ali
• Is Part Of: Journal of the Royal Society interface. Volume 14:Issue 130(2017)
• Publication Date: 2017-05-31
• Subjects: spider -- glue -- adhesion -- humidity -- biomimicry; Physical sciences -- Research -- Periodicals; Life sciences -- Research -- Periodicals; Interdisciplinary research -- Periodicals; 570.5
• DOI: 10.1098/rsif.2017.0228
• Languages: English
• ISSNs: 1742-5689

Abstract

Abstract : Orb web spiders use sticky capture spiral silk to retain prey in webs. Capture spiral silk is composed of an axial fibre of flagelliform silk covered with glue droplets that are arranged in a beads-on-a-string morphology that allows multiple droplets to simultaneously extend and resist pull off. Previous studies showed that the adhesion of capture silk is responsive to environmental humidity, increasing up to an optimum humidity that varied among different spider species. The maximum adhesion was hypothesized to occur when the viscoelasticity of the glue optimized contributions from glue spreading and bulk cohesion. In this study, we show how glue droplet shape during peeling contributes significantly to capture silk adhesion. Both overspreading and underspreading of glue droplets reduces adhesion through changes in crack propagation and failure regime. Understanding the mechanism of stimuli-responsive adhesion of spider capture silk will lead to new designs for smarter adhesives.