Two‐Way Shape Memory Alloy and Polymer Composite Hybrid Smart Actuator With High Speed, Accuracy, and Reversible Deformation

ABSTRACT Shape memory materials (SMMs) are promising future materials for smart actuators due to their simplicity and light weight. However, conventional SMMs suffer from irreversible deformation, limiting their use in applications that require repetitive tasks or reversible motion. To address this, two‐way hybrid actuators combining shape memory alloys (SMAs) and shape memory polymer composites (SMPCs) have been developed. However, the significant Young's modulus mismatch between SMA and SMP often results in an inconsistent recovery ratio, particularly hindering reverse recovery. This study presents a rapid and highly reversible SMA/SMP hybrid actuator achieved through both material and structural optimization. The epoxy‐based SMP resin was chemically modified to enhance its thermomechanical properties, including the glass transition temperature ( T g ) and elastic modulus. To further increase the mechanical properties of the hybrid actuator, a continuous carbon fiber reinforcement was introduced. Additionally, the introduction of transverse curvature in the structural design enabled a 100% reverse recovery ratio and sub‐second forward actuation through a snap‐through mechanism. Furthermore, the actuator demonstrated 8.6 times wider reversible deformation and a 4.9 times faster reverse recovery. These results demonstrate the feasibility of the developed high‐performance, fully reversible hybrid actuators for advanced applications such as robotic grippers and deployable aerospace structures.