Design and Experiment of Soft Gripper with Shape Memory Alloy Actuator

Compared to traditional rigid mechanical grippers, soft grippers have higher flexibility, stronger adaptability, simpler control, and are less likely to cause damage to objects. This paper first designs a soft actuator that uses the memory effect of shape memory alloy for motion, and the structure and control system of the soft actuator are simple. Based on the soft actuator, a five-finger soft gripper (Gripper-I) composed of the soft actuators and a base was designed. A series of gripping experiments were conducted on Gripper-I, which proved the effectiveness, stability, and safety of Gripper-I grips. However, limitations were observed in the gripping radius of Gripper-I during the experiment. To address this issue, a new type of three-finger soft gripper (Gripper-II) based on machine vision was developed to automatically adjust the gripping radius. Gripper-II consists of a base, servo adjustment devices, and soft actuators. Experiments were also performed on Gripper-II, which verified the function of automatic radius adjustment.