Omnidirectional Shape Proprioception for Untethered Shape Memory Alloy‐Driven Soft Robotic Arms

Soft robotic arms (SRAs) featuring high flexibility and adaptability exhibit great opportunities in unstructured environments, making them an ideal manifestation of embodied intelligence. However, the lack of stable proprioception and integrated structural design limits their real‐world applications. In this article, we propose a lightweight, modular shape memory alloy (SMA) driven SRA, integrated with a multi‐Hall‐magnet sensing system for accurate shape proprioception, while remaining untethered. Each segment is approximately 35 g in weight, allowing for easy assembly in series and seamless integration into complex systems. An omnidirectional shape proprioception method with self‐correction is presented, and it maintains high perception accuracy even under pronounced nonconstant‐curvature deformations. The results demonstrate a mean tip position error of approximately 1.39 mm in a single segment and a mean shape error of approximately 0.81% in the multisegment SRA. Experiments, including unstructured environment detection, pipeline navigation, and outdoor cooperation with a quadrotor drone, validate the robust performance of the sensing and actuation systems in real‐world conditions. The results demonstrate that the precise shape perception and modular integration enable SRAs to achieve strong application performance, further facilitating the practical deployment in real‐world scenarios.