%0 book part %@ %A Behl, M., Zotzmann, J., Lendlein, A. %D 2010 %J Advances in Polymer Science - Shape-memory Polymers %P 1-40 %R doi:10.1007/12_2009_26 %T Shape-Memory Polymers and Shape-Changing Polymers %U https://doi.org/10.1007/12_2009_26 %X The ability of polymers to respond to external stimuli is of high scientific and technological significance. In the last few years, research activities have been intensified substantially, exploring whether stimuli-sensitive polymers can be designed that move actively. In this review actively-moving materials were classified according to the underlying mechanisms enabling the shape changes: shape-memory polymers and shape-changing polymers / shape-changing gels were identified. The application spectra of these materials as well as the current developments were elucidated and general molecular design principles presented. When applicable, a further distinction according to the applied stimulus was made.