Fig. 1.

Propulsion through bistability. (A) Schematic of a 3D-printed soft robot (parts are false colored for visualization). (B) Energy potential of the bistable element with two stable states: I and III. The asymmetry in the curve indicates the need for a larger amount of energy to move backward than forward. The SMP muscle shown in Insets is rotated 90° with respect to the bistable element for visualization. (C) The SMP muscle in the deployed (I), transitioning (II), and activated phases (III). (D) Screen captures of the deployed robot in temperature ($T\ge T_{\mathrm{g}}$) at the different phases of activation.