supplemental_video1

The video shows the experiment described in the text: inversion of a helix by continuous unwinding. The parameters are: the unloaded coil radius R_0 = 3.9 mm, the pitch P_0 = 4.7 mm, the rod thickness d = 1.7 , the number of coils of unloaded coil n_0 = 9.5, the extension of unloaded coil z_0=0.2 L and the working extension z=0.82 L. At the very end the rod breaks at the upper clamp, allowing it to adopt its unloaded conformation in (-) state: the helix is collapsed and held by self contact between coils.