Fabrication and Testing of 3D Printed SMA Wire Embedded Thermoplastic Polyurethane Actuator

Abstract With automation and robotics growing across industries, the need for advanced manufacturing techniques, particularly for soft robotic components, is increasing. Additive manufacturing (AM) offers a fast, adaptable solution for developing complex actuator systems. This study examines how embedding Shape Memory Alloy (SMA) wires into 3D-printed thermoplastic polyurethane (TPU) structures can create actuators capable of adaptive, precise movements. Known for their shape-memory behavior when heated, SMA wires make ideal components for flexible, lightweight actuators. The goal of this study is to examine how well SMA wires integrate within TPU structures for actuator development. This includes optimizing designs to improve flexibility while using minimal material. A key focus is creating a reliable bond between the SMA wire and TPU, essential for long-lasting performance. Testing revealed that the embedded SMA wires responded predictably to temperature changes, with the actuators achieving specific movement angles — approximately 30° with rectangular hole designs. This movement consistency and strong adhesion to the TPU matrix contributed to the actuator’s durability. A functional test was completed with a three-finger flexible robot claw, which displayed smooth, controlled movements, underscoring the effectiveness of the design. The study suggests that using AM with SMA technology can enable lightweight, customizable actuators for robotics, aerospace, and other automated systems. In summary, SMA-embedded TPU actuators provide a promising way forward for enhancing soft robotic systems.