Integrating control and sensing in SMA-based actuators for shape-morphing hinge structures

Abstract Shape memory alloys (SMAs) offer unique advantages for compact, high-force actuators in shape-morphing systems, yet current solutions rarely provide modular torsional actuation with integrated closed-loop control and embedded sensing. Here, we present a novel modular hinge system featuring a compact, feedback-controlled torsional SMA actuator and miniaturized Hall effect sensing, designed for scalable and reconfigurable adaptive and shape-morphing structures. Our system enables real-time trajectory tracking with robust movement range and actuation time response achieving mean tracking errors below 1 ∘ and passive recovery above 40% in sinusoidal tests. By detailing actuator-sensor integration, proportional-integral-derivative control architecture, and wireless communication protocols, we demonstrate the advantages of modularity for constructing multi-degree-of-freedom assemblies. These results establish a versatile platform for high-performance, adaptive, and interactive shape-morphing technologies, advancing the field of smart materials for robotics and intelligent structures as a whole.