An Adaptive, Humanlike Robot Hand with Selective Interdigitation: Towards Robust Grasping and Dexterous, In-Hand Manipulation

This paper presents an adaptive robot hand that is capable of performing selective interdigitation, robust grasping, and dexterous, in-hand manipulation. The design consists of underactuated, compliant, anthropomorphic robot fingers that are implemented with flexure joints based on elastomer materials (urethane rubber). The metacarpophalangeal (MCP) joint of each finger can achieve both flexion/extension and abduction/adduction. The use of differential mechanisms simplifies the actuation scheme, as we utilize only two actuators for four fingers, achieving affordable dexterity. The two actuators offer increased power transmission during the execution of grasping and manipulation tasks. The importance of the thumb is highlighted with the use of two individual tendon-routing systems for its control. An analytical model is employed to derive the rotational stiffness of the finger flexure joints and select appropriate actuators. Selective interdigitation allows the robot hand to switch from pinch grasp configurations to power grasp configurations optimizing the performance of the device for specific objects. The design can be fabricated with off-the-shelf materials and rapid prototyping techniques, while its efficiency has been validated using an extensive set of experimental paradigms that involved the execution of complex tasks with everyday life objects.