Insect wing deployment

During its final transformation to morph into its adult form, just after hatching from its pupal case, an insect deploys its wings within minutes. The wings unfold rapidly from a wrinkled compact structure to a plane that subsequently solidifies to generate rigidity. We study wing expansion in Drosophila melanogaster. Expansion is regulated by increasing internal pressure and injecting a viscous liquid (hemolymph) into a folded deployable structure. We perform an experimental investigation of the morphological evolution of the wing during its deployment using Micro-CT imaging and optical microscopy. We then measure the tensile properties of the wing and build a minimal mechanical model that captures the nonlinear response of the origami-like folded structure. Finally, by combining scaling analysis, numerical simulations and experiments, we build a fundamental understanding of the wing’s expansion dynamics.