Design and Optimization of Actuator for Soft Bionic Finger

Currently, the researches on flexible mechanical fingers are mainly focused on motor-driven rigid fingers and soft robotic gripper. Unlike previous research, we have designed a soft bionic finger that can actuate multiple finger joints independently, which is more like a human finger. In the future, the fingers will not only provide the function of the catch but also used for rehabilitation treatment for patients with hand disability. In this paper, firstly, on the basis of tensile test for superelastic materials, the hyperelastic constitutive model is determined. Through the comparison of three different chambers structural forms of soft actuators, the internal longitudinal section shape of the model was optimized and the optimization results show that the semicircular internal cavity has better performance. Meanwhile, the FEM analysis method is applied to establish the motion model of the soft actuator. Finally, compared to traditional bionic fingers, experiments have verified that Three-joint soft finger proposed in this paper has better flexibility.