Sebastian Büsse


The predatory strike of dragonfly larvae - functional morphology, biomechanics and bio-inspired robotics

Department of Functional Morphology and Biomechanics, Institute of Zoology,
Kiel University, Kiel, Germany  


Throughout all animal groups, predator-prey relationships can cause an evolutionary arms race, which can lead to the development of predatory as well as defence systems. The countless examples can reveal elaborate biomechanical adaptions, some of which even improved technology.   Adult dragonflies roam the air in summertime and are a delight to every naturalist. The offspring of these colourful flying insects, however, are alien-like aquatic predators. They catch their prey with a unique and highly efficient grasping apparatus derived from a strongly modified mouthpart – the so-called prehensile labial mask. In the present talk, firstly, we will talk about life history driven ideas and simple biological experiments. Secondly, about the kinematics and biomechanics of the extensible mouthpart, which is thrust forward in a ballistic movement. Finally, about a bio-inspired robotic arm, as a proof of concept, which will be used to deepen our knowledge about the predatory strike itself.  

Here, a newly described independently loaded synchronised dual-catapult system is now hypothesised as the main driving mechanism of the predatory strike of dragonfly larvae. Two linked catapult systems, allowing for independent loading, are described. Both use a joint latch mechanism and one trigger muscle for synchronisation, resulting in a high-speed predatory strike that enables these aquatic key predators to successfully capture prey. After elucidating the biomechanics, a proof of concept is presented: a 3D-printed robotic system inspired by the insect's prehensile labial mask. Here, one of the great benefits of bio-inspired robotic systems becomes clear: one learns from nature to inspire technology but vice versa one can use this technology to learn about nature.