Design of Capsule-type Micro Actuator Utilizing Hydrogen Storage Alloys by Finite Element Analysis

Abstract

Capsule-type micro actuator driven by the volume change of hydrogen storage alloys (HSA-CMA) was proposed. HSA-CMA is specialized for the use in outer space, and its main application is anticipated to be mounted on the super multi-link space manipulator to capture space debris. It consists of a hollow sphere frame, a membrane of hydrogen storage alloy and a valve. The aim of this study is to examine the performance of HSA-CMA and to gain its optimal design. First, the eligible materials of the HSA membrane and the frame were discussed. Moreover, finite element analyses were carried out to determine the eligible topology parameters of HSA-CMA. Finally, the availability of HSA-CMA was evaluated by comparing its performance with that of other actuators. From the result of the analyses, the design map of HSA-CMA was developed and the available range of the design parameters was determined. The comparison result revealed HSA-CMA was superior to the piezoelectric actuator in the deformation and to the shape-memory alloy actuator in the generative force. It was concluded that HSA-CMA possesses high availability as an actuator used in space and its performance can be adjusted by varying the frame parameters according to the required performance.