Design and Analysis of Soft Grippers for Hand Rehabilitation

The goal of this paper is to develop a design methodology to create customized biomedical devices which can be fabricated through 3D printing technology. Due to the increasing demands of hand rehabilitation and prosthetic accessories, we focus on designing a pneumatically actuated soft gripper applicable on these issues. The gripper is composed of 3D printable soft material, which results in a safe interaction with human bodies due to inherently low modulus. Each gripper finger is designed to mimic the real-world movement of a human finger, where the complex physical finger locomotion is modelled as the continuous bending deformation of the soft gripper finger. Working as a compliant mechanism, the design process is performed to maximize the possible bending deformation. The topology optimization method is adopted to design the best performance gripper finger. The optimized gripper shows high consistence with human fingers because of the pseudo-joints. Sequentially, the designed gripper is directly fabricated through 3D printing technology and characterized with free travel trajectory tracking experiments.