Fig. 5.

Schematic illustrating the coupling between valves as viewed down the symmetry axis of the pod. When the bond between adjacent valves cracks, the valves begin to curl which in turn causes all the valves to rotate about the unbroken seams. The original uncracked arrangement of valves is shown in light gray. The mechanical model constructed from paper is given in Fig. S1 and its mechanical response to bending is given in Fig. S2.