In this paper, an attempt at summarizing the evolution and the state of the
art in the field of robot hands is made. In such exposition, a critical ev
aluation of what in the author's view are the leading ideas and emerging tr
ends is privileged with respect to exhaustiveness of citations.
The survey is focused mainly on three types of functional requirements a ma
chine hand can be assigned in an artificial system, namely, manipulative de
xterity, grasp robustness, and human operability. A basic distinction is ma
de between hands designed for mimicking the human anatomy and physiology, a
nd hands designed to meet restricted, practical requirements. In the latter
domain, arguments are presented in favor of a "minimalistic" attitude in t
he design of hands for practical applications, i.e., use the least number o
f actuators, the simplest set of sensors, etc., for a given task. To achiev
e this rather obvious engineering goal is' a challenge to our community. Th
e paper illustrates some of the new, sometimes difficult, problems that are
brought about by building and controlling simpler, more practical devices.