FRST (IMAGE) Singapore University of Technology and Design Caption A Fast-Response, Stiffness-Tunable (FRST) soft actuator is fabricated by hybrid multimaterial 3D printing. Owing to the thermomechanical properties of an embedded shape memory polymer layer, the actuator exhibits flexibility when heated yet high stiffness (120 times its purely elastomeric counterpart) when cooled. Assisted by Joule-heating and fluidic cooling, the heating-cooling cycle is completed within 32 s. Credit SUTD Usage Restrictions Image should be used with the appropriate caption and credit. 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.