Journal of Bionic Engineering (2024) 21:1290–1304https://doi.org/10.1007/s42235-024-00492-9

A Bio-inspired Mutual-hook Strategy for the Soft Finger to Improve Load-bearing Capacity and Grasping Stability

Jie Huang1,2,3  · Lingjie Gai1,2  · Xiaofeng Zong1,2  · Yunquan Li3 

1 School of Automation, China University of Geosciences, Wuhan 430074, China

2 Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex System, Wuhan 430074, China

3 The Shien-Ming Wu School of Intelligent Engineering, South China University of Technology, Guangzhou 510641, China

Abstract

Soft grippers have great potential applications in daily life, since they can compliantly grasp soft and delicate objects. However, the highly elastic fngers of most soft grippers are prone to separate from each other while grasping objects due to their low stifness, thus reducing the grasping stability and load-bearing capacity. To tackle this problem, inspired from the venus fytrap plant, this work proposes a mutual-hook mechanism to restrain the separation and improve the grasping performance of soft fngers. The novel soft gripper design consists of three modules, a soft fnger-cot, two Soft Hook Actuators(SHAs) and two sliding mechanisms. Here, the soft fnger-cot covers on the soft fnger, increasing the contact area with the target object, two SHAs are fxed to the left and right sides of the fnger-cot, and the sliding mechanisms are designed to make SHAs stretch fexibly. Experiments demonstrate that the proposed design can restrain the separation of soft fngers substantially, and the soft fngers with the fnger-cots can grasp objects three times heavier than the soft fngers without the proposed design. The proposed design can provide invaluable insights for soft fngers to restrain the separation while grasping, thus improving the grasping stability and the load-bearing capacity.

Keywords Soft robotics · Soft bionic fnger-cot · Soft hook actuator · Grasping stability · Load-bearing capacity