Active rapid morphing mechanism of the Venus flytrap

The Venus flytrap (Dionaea muscipula) exhibits rapid snapping in about 100 ms, which has long fascinated scientists as one of the fastest botanical movements. Its motion is mechanically initiated by stimulating the trigger hairs, and accelerated by using the snap buckling instability of the poroelastic curved shell geometry of the leaves. At a macroscopic level, its kinematics and dynamics are well understood. However, the mechanism to actively change its natural curvature remains unknown. Here we first characterise the ‘active’ dynamics of the Venus flytrap by removing the buckling instability. We probe the change of its mechanical properties before and after triggering the closure and investigate the key components driving this rapid motion at a microscopic level. Then we elucidate the physical mechanisms underlying the rapid morphing of the Venus flytrap. A better understanding of active movements in plants could allow us to design new rapid and programmable morphing structures.