A design procedure for a novel concept of shape-memory-alloy-actuated finger exoskeleton

Abstract

This paper provides a thorough investigation demonstrating the feasibility of an innovative finger exoskeleton design concept in a compact, self-contained shape using Shape Memory Alloy (SMA) wires. This novel design integrates SMA wires directly onto the finger body, eliminating the need for bulky wrist actuators. Strategically positioned, the SMA wires serve as both actuators and sensors. The proposed exoskeleton can be used for rehabilitation purposes or for hand augmentation during manufacturing tasks. To properly design the exoskeleton, multiple simulation models have been developed. Kinematic and dynamic analyses were conducted to determine the sufficient motion ranges and forces as a function of SMA wire locations. Both models and experiments confirm the feasibility of integrating SMA wires within the limited space near the fingers. Several experimental tests were conducted to validate the simulation model results. Moreover, thermal-camera measurements confirm that SMA wires can be safely isolated and attached to the finger, preventing skin overheating. All simulation and experimental outcomes indicate the reliability of the proposed design procedure and the engineering feasibility of our novel finger.