The Shape-Memory Polymer Actuator Sheet (IMAGE) Helmholtz-Zentrum Hereon Caption The shape-memory polymer actuator sheet coated with stem cells shrunken when cold (left) and stretched when heated (right). Credit Source: Polymeric sheet actuators with programmable bioinstructivity, Zijun Deng, Weiwei Wang, Xun Xu, Oliver Gould, Karl Kratz, Nan Ma, and Andreas Lendlein, <em>Proceedings of the National Academy of Sciences</em>, 2020, doi: 10.1073/pnas.1910668117 Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.