Abstract: A rotational actuator assembly employs a first torsion actuator having a shape memory alloy (SMA) tube with a first trained twist direction and a second torsion actuator having a SMA tube with an opposite trained twist direction collinear with the first torsion actuator with abutting proximal ends. A central fitting joins the proximal ends. A control system for temperature control of the first torsion actuator and second torsion actuator about an average temperature provides combined antagonistic rotation of the central fitting.

Abstract: A rotational actuator assembly employs a first torsion actuator having a shape memory alloy (SMA) tube with a first trained twist direction and a second torsion actuator having a SMA tube with an opposite trained twist direction collinear with the first torsion actuator with abutting proximal ends. A central fitting joins the proximal ends. A control system for temperature control of the first torsion actuator and second torsion actuator about an average temperature provides combined antagonistic rotation of the central fitting.

Abstract: The present invention presents a system for a compound actuator. The system includes first and second electrode layers each including two electrode sections, an intermediate electrode layer between the first and second electrode layers, and first and second electrostrictive materials that change length in an applied electrical field. The first electrostrictive material is positioned between the first and intermediate electrode layers. The second electrostrictive material is positioned between the intermediate and second electrode layers. The first electrostrictive material has a first length adjoining the first electrode section and a second length adjoining the second electrode section. The second electrostrictive material has a third length adjoining the fourth electrode section and a fourth length adjoining the fifth electrode section.