Shaping by active deformation of soft elastic sheets

One shaping method of soft elastic bodies is growth. This method, which is very common in natural systems and much less in man-made structures, is inherently different from shaping by external loading. In the second case the body responses passively to the constraints imposed on its boundaries. It has a reference stress-free configuration and the task is to compute and minimize the elastic energy of configurations that fulfill the boundary conditions. In the case of self-shaping by growth, the body is free in space, but contains a field of active growth, or deformation, which determines the shape of the body.