Christoph Bruns

Biomechanics of micro-damage in insect exoskeletons

The cuticle of insects is a fascinating and diverse material which is also one of the most common materials on earth. Despite the relevance of this composite material, numerous questions remain unexplored due to its complexity. Most scientific studies on the biomechanical properties of the insect cuticle only deal with static loads. However, instead of static loads, the exoskeleton of insects is rather exposed to cyclic loads in everyday life. However, only little is known about how insects cope with cyclic loading and fatigue-induced damages. The aim of this PhD project is to investigate how the insect exoskeleton resists cyclic loading and reacts to fatigue-induced damages. In addition, this project will investigate whether the fatigue properties of exoskeletal body parts differ and whether the fatigue properties correlate with the individual function of the exoskeletal body part or the histological composition of the cuticle.
To answer these questions, biological and material science approaches will be combined. Biomechanical tests with non-cyclic short-term and cyclic long-term loads will be performed to analyze the fatigue properties and to cause fatigue-induced micro-damages. Afterwards, imaging techniques such as X-ray tomography, scanning electron and light microscopy as well as finite element models will be used to analyze damages, repair processes and modifications in the cuticle and to determine structural resistance mechanisms. The PhD project will provide fundamental insights into fatigue and counteracting strategies of the insect cuticle.