Tendon-Driven Gripper with Variable Stiffness Joint and Water-Cooled SMA Springs

In recent years, there has been an increase in the development of medical robots to enhance interventional MRI-guided therapies and operations. Magnetic resonance imaging (MRI) surgical are particularly attractive due their ability provide excellent soft-tissue contrast during these procedures. This paper describes a novel design for tendon-driven gripper that utilizes four shape memory alloy (SMA) spring actuators variable stiffness joints controlled by SMA coils use MRI robot applications. The contact force link is determined mechanical properties (SSA) angle each linkage, joint can be adjusted varying electrical current applied coil. To efficiency SSAs, new cooling system using water proposed implemented. validate effectiveness our gripper, we conducted three types experiments, namely, single SSA experiment, coil whole experiment. experimental results demonstrate water-cooling effectively solve temperature issues SMA, austenite state higher than martensite state. Moreover, experiments show presented capable grasping holding objects various shapes weights.