Continuous and programmable photomechanical jumping of polymer monoliths

Abstract

The jumping motion is adapted by Earth's creatures to achieve rapid maneuverability and energy-efficient hurdling over uneven terrains or large obstacles. Herein, the continuous photomechanical jumping of polymer monoliths with on-demand height and angle programmability is reported. Upon exposure to actinic light, self-assembled spring-like molecular geometry of azobenzene-functionalized liquid crystalline polymers provide on-demand jumping via snap-through of non-isometric structures. The finite element method simulation quantitatively describes stress–strain responsivity of the experimental jumping. Remarkably, the maximum jumping height reaches 15.5 body length (BL) with the maximum instantaneous velocity of 880 BL s−1. We demonstrate programmable jumping height and angle by varying macroscopic geometry and light intensity profile. Finally, four continuous and directional jumping sequences are demonstrated within 5 s to overcome an obstacle.