Steerable and Agile Light‐Fueled Rolling Locomotors by Curvature‐Engineered Torsional Torque

Abstract

Abstract On‐demand photo‐steerable amphibious rolling motions are generated by the structural engineering of monolithic soft locomotors. Photo‐morphogenesis of azobenzene‐functionalized liquid crystal polymer networks (azo‐LCNs) is designed from spiral ribbon to helicoid helices, employing a 270° super‐twisted nematic molecular geometry with aspect ratio variations of azo‐LCN strips. Unlike the intermittent and biased rolling of spiral ribbon azo‐LCNs with center‐of‐mass shifting, the axial torsional torque of helicoid azo‐LCNs enables continuous and straight rolling at high rotation rates (≈720 rpm). Furthermore, center‐tapered helicoid structures with wide edges are introduced for effectively accelerating photo‐motilities while maintaining directional controllability. Irrespective of surface conditions, the photo‐induced rotational torque of center‐tapered helicoid azo‐LCNs can be transferred to interacting surfaces, as manifested by steep slope climbing and paddle‐like swimming multimodal motilities. Finally, the authors demonstrate continuous curvilinear guidance of soft locomotors, bypassing obstacles and reaching desired destinations through real‐time on‐demand photo‐steering.

Keywords

• amphibious multimodal actuation
• helical soft robot
• liquid crystal polymer network
• on‐demand steering
• photo‐mechanical rolling