Design a new model for artificial finger by using SMA actuators

Abstract

Shape Memory Alloy (SMA) wires are currently employed in robotics, as well as in actuators for various fields such as prosthetic limbs and medical equipments, where they can be a good alternative to traditional actuators. SMA wires are particularly suitable for simple designed small devices with and high power-to-weight ratio, and are also an optimum solution when employed as sensors and actuators simultaneously. A new dynamic model has been designed and provided for an artificial finger by using properties of SMA actuators. A robotic finger has been designed and modeled with 3 DOF, revolute joints, SMA wires as the tendon in order to adduction each phalanges of finger and springs to restore each phalanges of finger in original position. This model has been simulated and validated in MATLAB/Simulation under different electrical current as an input. At the end, robot performance had been studied in achieving the position of each phalanges finger as outputs and compared with others. The results compared with actual measured data, show how well the model performes to reduce the errors and increase the accuracy of the artificial finger model.