Highly Anthropomorphic Finger Design With a Novel Friction Clutch for Achieving Human-Like Reach-and-Grasp Movements

Area of Science:

• Biomedical Engineering
• Robotics
• Mechanical Engineering

Background:

• Designing prosthetic fingers that mimic human movement and anthropomorphic qualities (appearance, size, weight) is challenging.
• Human finger motion requires distinct consistency during reaching and adaptability during grasping.
• Conventional designs struggle to balance consistency and adaptability due to bulky components or complex routing.

Purpose of the Study:

• To propose a novel, compact friction clutch mechanism for prosthetic fingers.
• To achieve human-like reach-and-grasp movements by integrating consistency and adaptability.
• To develop a highly anthropomorphic prosthetic finger design.

Main Methods:

• A novel friction clutch system with a single tendon and slider is proposed, integrated within the metacarpal bone.
• Friction force is utilized to counteract gravity effects on phalanges during motion.
• The mechanism is designed to automatically switch between consistent and adaptive motion modes.

Main Results:

• The proposed prosthetic finger demonstrates consistent motion regardless of spatial posture during reaching.
• It exhibits adaptive motion for grasping various objects.
• The design is highly anthropomorphic, weighing 18.9 g and matching adult finger size.
• Experiments validated the theoretical effectiveness and motion performance.

Conclusions:

• The novel friction clutch design successfully combines motion consistency and adaptability in a compact, anthropomorphic prosthetic finger.
• This approach offers a new strategy for prosthetic hand design and shows potential for hand rehabilitation applications.