Development of an SMA testing rig for finger prosthesis / Mohamad Amlie Abu Kasim

This paper is focuses on the experimental verification of a SMA actuation system. The aim of this project is utilizing Shape Memory Alloy (SMA) as actuators in controlling the flexion-extension of finger prosthesis and the preparing the experiment set-up for testing the SMA wire. The shape memory alloy used in this study is a straight wire which is made of Nikel Titanium Alloy called Nitinol [10]. The SMA has advantages such as powerful, lightweight, simple joining and compact [2]. In this project SMA wire will act as tendons. When current is applied, the SMA wire will be heated and transformation will happen from the Austenitic phase to Martensite phase [6]. In that phase the microstructure of SMA are also changed. The advantaged is producing significant forces and displacement capabilities while consuming only low power and low energy [3]. An actuator unit that consists of SMA wire and spring is set-up, and transfer function of the actuator unit related to applied voltages and generated forces are measured [12]. The aim is to find out the relationship between forces and voltage. From that graph, important characteristics and behavior of SMA can be studied and then applied for the finger prosthesis [12].