2021/03/07 by Elio J. Challita, Symone L. M. Alexander, Challita, Elio J. +11 · 1 citation
Biochemistry, Genetics and Molecular Biology · Engineering · Materials Science · #Adhesion, Friction, and Surface Interactions #Biological Physics (physics.bio-ph) #FOS: Physical sciences #Insect and Arachnid Ecology and Behavior #Silk-based biomaterials and applications
paper · pdf · doi:10.48550/arxiv.2103.05756
openalex publication_date 2021/03/07 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
We develop a mathematical model to capture the web dynamics of slingshot\nspiders (Araneae: Theridiosomatidae), which utilize a tension line to deform\ntheir orb webs into conical springs to hunt flying insects. Slingshot spiders\nare characterized by their ultrafast launch speeds and accelerations (exceeding\n1300 m/s2), however a theoretical approach to characterize the underlying\nspatiotemporal web dynamics remains missing. To address this knowledge gap, we\ndevelop a 2D-coupled damped oscillator model of the web. Our model reveals\nthree key insights into the dynamics of slingshot motion. First, the tension\nline plays a dual role: enabling the spider to load elastic energy into the web\nfor a quick launch (in milliseconds) to displacements of 10-15 body lengths,\nbut also enabling the spider to halt quickly, attenuating inertial\noscillations. Second, the dominant energy dissipation mechanism is viscous drag\nby the silk lines - acting as a low Reynolds number parachute. Third, the web\nexhibits underdamped oscillatory dynamics through a finely-tuned balance\nbetween the radial line forces, the tension line force and viscous drag\ndissipation. Together, our work suggests that the conical geometry and\ntension-line enables the slingshot web to act as both an elastic spring and a\nshock absorber, for the multi-functional roles of risky predation and\nself-preservation.\n