Hierarchical Artificial Muscle with Nonlinear Elasticity for Antagonistic and Cyclic Robotics. - Tsai, Samuel; Cheng, Liuyang; Albazroun, Ali; Wang, Qiong; Kim, Jeongmin; Tekinalp, Arman; Kim, Soonwook; Simcox, Charlie; Downing, Ryne; Sivaramakrishnan, Vagish; Carsello, Grace; Bimrose, Miles; et al. (Advanced Science, 2026)