Shape memory materials.

Shape memory materials play an important role in the biologically-inspired smart materials domain. They are able to drastically modify their own shape and the behaviour of systems in which they are embedded. In crystalline solids the shape memory effect is associated with several of martensitic reversible phase transitions. In amorphous materials the combination of molecular mobility and of entropic elasticity allows very important recoverable strains. The imagination of scientists and technologists is always very active in the fascinating world of multishaped materials. New materials are being developed, new uses appear. The most pertinent and promising applications are briefly reviewed.