Miniature leaping robots are desired to perform fast, programmable, and versatile motions. In this study, we present our approach for harnessing the impulsive unknotting process triggered upon heating millimeter-sized knots made from Kevlar-reinforced liquid crystal elastomer (LCE) composite fibers. The LCE shell with twisted mesogens undergoes torsional deformation, generating an actuation force that overcomes friction, converting the stored elastic energy into kinetic energy for launching tall