Meeting Abstract
Numerous living systems employ biological springs and latches to mechanically amplify their power for ultrafast movements. The biomechanics of power-packed, ultrafast motion in both natural and robotic systems is an emergent topic of study, but is often one-sided, focusing solely on storage and amplification of power. How ultrafast organisms dissipate excess energy and prevent catastrophic self-destruction remains relatively unexplored. In this work, we focus on the dynamics of `Slingshot Spiders’ to study both the energy storage and energy dissipation mechanisms involved in repeatable ultrafast motion. We bring high-speed cameras to the Amazon Rainforest and quantify the ultrafast hunting dynamics of the “Slingshot Spider” (SS) for the first time, since its first naturalist description almost a century ago. We discover that the SS exploits the stored elastic energy of their conical silk webs `springs’ to achieve accelerations exceeding 1300 m/s2 (130 g-force) which, is the fastest full body motion achieved by an arachnid. The web release mechanism occurs in less than a millisecond, achieving accelerations faster than a flea jump. This need for speed underscores an ambush hunting strategy, where SS explosively hurls itself and its web to catch giant flying insects in mid-air, increasing its predation success compared to traditional insect-web-collision strategy. Finally, we explore the design space of SS’s dynamics utilizing a damped oscillator model, uncovering the dual-functionality of the web structure: to both load elastic energy for powerful motion and to efficiently dissipate excess energy for self-survival. Our work highlights an underappreciated, yet crucial evolutionary trade-off in ultrafast systems that enables them to safely execute their extreme movements hundreds of times over their lifetime, without compromising on power output.
