Shape Change Mechanisms in Biological Materials

The shape change of plant and animal tissues fulfills a variety of functions from organ growth to locomotion or seed dissemination. Various physical mechanisms, from fiber contraction to osmotic pressure and atmospheric dehydration, are at the origin of such shape changes. Fiber orientation distributions control the geometry of shape change and constitute, therefore, the alphabet for such programmed transformations. The talk reviews recent work on seed locomotion and capsule opening, on collagen fiber contraction as well as fiber tension-controlled tissue growth.