RII Track-4:NSF: Ultrafast Gripping and Release Mechanisms in Slingshot Spider Legs

Theridiosomatids, also known as Slingshot Spiders (SS), are a fascinating family of tiny arachnids, about the size of a pinhead, that utilize 3-D cone-shaped webs as ultrafast slingshots to capture flying insects. Slingshot spiders are among the very few arachnids known to actively employ a tool (the web) to accelerate 10 times faster than a cheetah.

Their legs and claws can withstand forces 100 times greater than their body weight and can initiate the slingshot motion in less than a millisecond. Investigating the anatomy of slingshot spider legs and claws will enable us to identify key design elements for small-scale, rapid-response mechanical systems. Through collaboration between Dr.

Symone Alexander and her research team in the Department of Chemical Engineering at Auburn University, and Drs. Hannah Wood and Jonathan Coddington at the Smithsonian Institute National Museum of Natural History (NMNH), engineering and biological approaches will be used to identify, catalog, and connect unique features of slingshot spiders across species.

Through this work, we will develop and implement cutting-edge modeling and imaging techniques to create new technology for handling and analyzing delicate or sensitive materials, all inspired by the SS and its unique prey capture strategy.

This Research Infrastructure Improvement Track-4 EPSCoR Research Fellows project will provide a fellowship to an Assistant Professor and training for a graduate student at Auburn University. The project will be conducted in collaboration with researchers at the Smithsonian Institute National Museum of Natural History (NMNH). The goals of this work are to: (1) Utilize micro-computed tomography (micro-CT) to identify leg segment morphologies that enable SS to withstand large tensile forces over extended timeframes; (2) Use micro-CT to identify claw morphologies that enable SS to grip/release silk at high speeds; and (3) Compare closely related theridiosomatid species that do and do not use the slingshot motion to understand the evolution of latching morphologies for prey capture.

The project will couple these findings with high-speed video data to provide a multiscale, mechanistic understanding of SS prey capture. The host site, NMNH, provides a unique opportunity to compare morphologies of closely related species. The project will significantly advance the exploration of load and release mechanisms of SS by expediting the acquisition of essential cross-cutting expertise in spider morphology and biomechanics.

This work will also advance fundamental knowledge by revealing the morphologies necessary to withstand high tension forces and rapidly respond to environmental stimuli. Exploring SS leg morphology, especially the less-studied proximal joints, will lead to the identification of a lightweight, small-scale biomechanical system capable of withstanding large loads with sub-millisecond response times, inspiring the design of new micromechanical systems and responsive actuators.

The investigation of claw morphology will uncover design parameters for ultrafast gripping technology that can generate high frictional forces without damaging delicate materials. Additionally, comparative morphology across theridiosomatid species will aid in identifying new species, expanding NMNH collections, and providing new insights into the evolution of SS ultrafast prey capture.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.