Latch and release how hinge morphology and mechanics enable the explosive click of Coleoptera Elateridae


Meeting Abstract

65-5  Saturday, Jan. 5 14:30 – 14:45  Latch and release: how hinge morphology and mechanics enable the explosive click of Coleoptera Elateridae BOLMIN, O; WEI, L; HAZEL, A; ALLEYNE, M; DUNN, A; WISSA, A*; University of Illinois Urbana-Champaign; University of Illinois Urbana-Champaign; University of Illinois Urbana-Champaign; University of Illinois Urbana-Champaign; University of Illinois Urbana-Champaign; University of Illinois Urbana-Champaign awissa@illinois.edu http://bamlab.mechse.illinois.edu/

The maneuverability of insects is enabled, in part, by sophisticated energy storage and release processes involving composite materials and architectures. Click beetles (Coleoptera: Elateridae), for example, use a complex hinge mechanism in the thoracic region to latch and snap their bodies, which when unconfined manifests as a legless jump. Understanding how a beetle can accelerate from a stationary position requires an integrated description of the morphology, architecture, and function of the latch mechanism. In this presentation, we focus on the unique morphology and function of the peg and mesosternal lip, which make up the hinge. We first describe the anatomy in detail and define the most important measurements using environmental scanning electron microscope and Computerized Tomography Scans. We then use beam bending mechanics models to quantify the peg stiffness and its contribution to the sturdy brace position from which the snap initiates. Finally, we used a micro-mechanical experiment to measure the force-displacement characteristics of the snap maneuver. The critical function of this anatomy is comprehensively described for the first time through an integration of specific anatomical morphology and engineering mechanics. Results show that the contact surface area of the peg, as well as the force required to overcome the latching mechanism increase as the mass increases, while the peg bending stiffness decreases with increasing body mass.

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