Snapping mechanics of the Venus flytrap (Dionaea muscipula)

Significance The rapid closure of the carnivorous Venus flytrap (Dionaea muscipula ) snap-trap incorporates snap-buckling instability as a speed boost. The trap actuation principles required to overcome the involved energy barrier, as determined by the double-lobe curvature, have remained speculative until now. Here we used 3D digital image correlation for the analysis of trap deformation during closure for both the outer and the inner trap surfaces. Accompanying biomechanical and physiological experiments revealed that successful snapping relies on full trap hydration. In combination with FEM simulations elucidating the mechanical contribution of the various trap tissues to the motion, we show that the trapping mechanics incorporate an elaborate interplay between swelling/shrinking processes of the various tissue layers and the release of trap-internal prestress.