Dexterous Robotic Hand Based on Rotational Shape Memory Alloy Actuator-Joints

In this study, we present a novel Shape Memory Alloy (SMA)-actuated robotic hand which can provide a higher level of dexterity and compliance. The mechanical structure and actuation of the robotic hand are designed similar to the musculoskeletal system of a human hand. SMAs are used in a similar manner where muscles and ligaments are applied in a human hand. In our design, the compliance of SMAs are used to manipulate soft, fragile, and/or rigid objects more adaptively and naturally. In particular, SMA actuators can provide a high power-to-weight ratio, which is preferable for a compact and lighter design. Each finger joint in the hand is actuated independently. Thus, the robotic hand can achieve dexterous in-hand manipulation. The grasping and in-hand manipulation experiments verify the robot design using open-loop control and closed-loop control, respectively.