Today’s robotics systems operate by way of hydraulic, pneumatic, and electrical power. Electric motors have become progressively smaller, with high power-to-weight ratios, enabling them to become the dominant means by which robots are powered.
Robots are, of course, comprised of several different elements, depending on their purpose. The hand of a robot, for instance, is referred to in the industry as an “end effector.” End effectors may be specialized tools, such as spot welders or spray guns, or more general-purpose grippers.