Wireless Autonomous Soft Crawlers for Adjustable Climbing Actuation

Artificial soft actuators, featured with non-equilibrium internal circumstance and fast, programmable shape transformations, have attracted strong research interest recently due to their flexibility, highly controllable, and designability. However, wireless soft actuators, achieving the locomotion on different large slopes with multiple energy conversion, have been rarely reported. Herein, we create a asymmetric bilayer strategy to construct autonomous soft crawler via “breathing” moisture to motivate the mechanical deformation. The soft crawlers present conspicuous performances including periodic tumbler locomotion predicted via improved Timoshenko’s equation, multiple reversible shape-morphing (circle, helix, despiralization, etc. ) determined by their fiber orientation, controlled drive mode (front drive and rear drive) and rapid climb speed (4.76 cm/min) at wide slope angles. Through architecture design, they can be series-wound or shunt-wound to construct multi-joint complex actuators. Besides climbing, a intelligent soft ring-pull with admirable cycle performance for preventing overheating or something untouchable, has been proposed. The soft crawlers also realize multiple energy conversion to be actuated by light irradiation. We envision that this soft crawler system has an enormous potential in intelligent machine, microscopic diagnosis and treatment, biosensing, energy harvesting and conversion.