A novel variable stiffness soft finger actuated by shape memory alloy

Article type: Research Article

Authors: Li, Junfeng | Yin, Haibin^* | Tan, Yuegang

Affiliations: School of Mechanical and Electronic Engineering, Wuhan University of Technology, Wuhan 430070, Hubei, China

Correspondence: [*] Corresponding author: Haibin Yin, School of Mechanical and Electronic Engineering, Wuhan University of Technology, Wuhan 430070, Hubei, China. Tel.: +86 15926461392; E-mail:chinaliuyin@whut.edu.cn

Abstract: The purpose of this research is to present a new kind of soft finger which can achieve variable stiffness actuation by heating the fixed SMA fibers. First, the material and design method of the soft finger are described. Next, the stiffness of the finger with different heating currents for the SMA is measured and the results show the increase of stiffness around 21.5 per cent from the low stiffness to high stiffness. Finally, the maximum pulling force of the soft gripper with variable stiffness is measured, which demonstrates that output force of the finger's tip can be adjusted by changed stiffness. This variable stiffness structure for a manipulator could greatly benefit applications such as human-safe robotics and systems in which robots need to exhibit high flexibility to conform to their environments.

Keywords: Variable stiffness, SMA actuator, gripper

DOI: 10.3233/JAE-160091

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 53, no. 4, pp. 727-733, 2017