Human manipulation skills represent a pinnacle of their voluntary motor functions, requiring the coordination of many degrees of freedom and processing of high-dimensional sensor input to achieve such a high level of dexterity. Thus, we attempt to answer whether the human hand, with its associated biomechanical properties, sensors, and control mechanisms, is an ideal that we should strive for in robotics-do we really need anthropomorphic robotic hands? This survey can help practitioners to make the trade-off between hand complexity and potential manipulation skills. We provide an overview of the human hand, a comparison of commercially available robotic and prosthetic hands, and a systematic review of hand mechanisms and skills that they are capable of. This leads to follow-up questions. What is the minimum requirement for mechanisms and sensors to implement most skills that a robot needs? What is missing to reach human-level dexterity? Can we improve upon human dexterity? Although complex five-fingered hands are often used as the ultimate goal for robotic manipulators, they are not necessary for all tasks. We found that wrist flexibility and finger abduction/adduction are often more important for manipulation capabilities. Increasing the number of fingers, actuators, or degrees of freedom is not always necessary. Three fingers often are a good compromise between simplicity and dexterity. Non-anthropomorphic hand designs with two opposing pairs of fingers or human hands with six fingers can further increase dexterity, suggesting that the human hand is not the optimum. Consequently, we argue for function-based rather than form-based biomimicry.

翻译：人类操作技能代表了其自主运动功能的顶峰，需要协调多个自由度并处理高维传感器输入才能实现如此高水平的灵巧性。因此，我们试图回答：具有相关生物力学特性、传感器和控制机制的人类手是否是机器人学应当追求的终极目标——我们真的需要拟人化机器人手吗？本综述可帮助从业者在手部复杂性与潜在操作技能之间进行权衡。我们概述了人类手的结构，比较了市售机器人手与假肢手，并系统回顾了现有手部机构及其能够实现的技能。这引出了后续问题：实现机器人所需大多数技能对机构和传感器的最低要求是什么？要达到人类水平的灵巧性还缺少什么？我们能否超越人类的灵巧性？尽管复杂的五指手常被视为机器人操作器的终极目标，但它们并非所有任务所必需。我们发现手腕灵活性和手指外展/内收通常对操作能力更为重要。增加手指数量、驱动器或自由度并非总是必要。三指设计往往是简洁性与灵巧性之间的良好折衷。具有两对相对手指的非拟人化手部设计或六指人类手可进一步提升灵巧性，这表明人类手并非最优解。因此，我们主张基于功能而非基于形态的仿生学。