To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie S2. Shape memory muscle of different thickness exhibiting different time to activation. Harnessing bistability for directional propulsion of soft, untethered robots Tian Chen, Osama R. Bilal, Kristina Shea, and Chiara Daraio PNAS. 2018. 115:5698-5702 DOI: 10.1073/pnas.1800386115 Download Original Video Browse All Videos »