An Experimental Study on a SMA Driven Pressurized Hyper-redundant Manipulator

This study describes the design and fabrication of a pressurized hyper-redundant manipulator driven by high strain shape memory alloy (SMA) actuators. Hyper-redundant devices are characterized by repeating independently controlled structures connected in series; their architecture is comparable to that of a snake or worm. The proposed design is composed of four identical modules; each providing three degrees of freedom from three symmetrically positioned actuators. The manipulator stiffness and actuator return-force are controlled by pressurized air, injected at the base of the manipulator. Tests on a single unit module have demonstrated that the design could achieve rotations of over 50° and displacements of over 40% at a frequency of 1/20 Hz.