Application of SMA Actuators to Spacesuit Glove Mobility

A common problem with space suit systems is overly rigid gloves that resist astronaut finger motion and gripping. In this paper, the design of a mechanism is considered that exploits the small-scale nature of shape memory alloys for actuating glove fingers to assist hand gripping. The design problem is introduced by considering the objectives, constraints, and variables relevant to a spacesuit glove actuator design. Advantages and disadvantages of shape memory alloys for this application are presented. The selection of a specific shape memory alloy composition is considered, as well as specimen dimensions and connection configuration, based on ergonomic considerations. Mechanism actuation was then simulated using finite element analysis of a simulated glovefinger-actuator assembly. The results of this paper show that the designed shape memory alloy mechanism is feasible for assisting astronaut hand gripping.