New smart actuator enables rapid robot motion without complex motors

Researchers at the Korea Advanced Institute of Science & Technology (KAIST) have developed a novel two-way shape memory hybrid actuator that enables rapid, reversible motion without the need for traditional, complex motors. This lightweight actuator combines shape memory alloys (SMAs) and shape memory polymers (SMPs), enhanced with carbon fiber reinforcement and a tape spring-inspired “snap-through” structure. This design allows the actuator to bend when heated and return to its original shape upon cooling in under a second, achieving nearly 100% shape recovery with significantly wider deformation and faster reverse motion compared to existing materials. The innovation addresses key limitations of conventional shape memory materials, which typically exhibit one-way, irreversible motion or lack mechanical strength for demanding applications. By integrating SMAs’ reliable thermal recovery with SMPs’ flexible deformation and reinforcing the composite, the actuator delivers consistent, repeatable performance without complex control systems. This breakthrough paves the way for practical use in advanced robotics, deployable space structures, and other fields requiring lightweight,