A Bioinspired Composite Finger with Self-Locking Joints

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

2 Scopus Citations
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Original languageEnglish
Pages (from-to)1391-1398
Journal / PublicationIEEE Robotics and Automation Letters
Issue number2
Online published2 Feb 2021
Publication statusPublished - 2 Apr 2021


This paper presents a bioinspired composite finger with self-locking joints that can perform long-time and high-load (27.8 N) grasping tasks with low power consumption. Inspired by the ratchet wrench, the self-locking joint includes a ratchet mechanism to provide a large grip force for the finger through mechanical interlocking. The finger uses two shape memory alloy coils (SMAc) to drive the tendon and open the interlocking. The locked position and strength are studied through kinematics and finite element analysis. In the experiments, the motion of the finger is optimized to achieve a robust grasp. A portable three-finger gripper is used to grasp and lift heavy objects with high payload-to-weight ratio. The gripper with remote control shows its potential applications, for example, in assisting unmanned aerial vehicles to perform tasks of perching and grasping.

Research Area(s)

  • biologically-inspired robots, grasping, grippers and other end-effectors, Soft robot materials and design