Roll up your sleeves
When you push up your sleeves, wrinkles form, which eventually evolve into ridges (pictured). As familiar as you may be with this phenomenon, have you ever thought about its underlying mechanism? It involves the complex nonlinear mechanical behaviour of large deformations and surface instabilities, which in turn give rise to a sophisticated morphological evolution. And now, Yifan Yang and co-workers have revealed a hitherto unknown post-buckling behaviour that involves multiple bifurcation transitions (Phys. Rev.
