When you think of "robot," what do you envision? Does your robot walk upright like "C3PO" or roll like "R2D2?" Does your robot have a rigid mechanical face or an expressionistic soft face? Does it pick up objects or does it function as a robotic vacuum? Perhaps your intelligent system works in the medical field or in robotic welding. Since there are a number of different uses for robotics and automation, it's reasonable to assume there are many, many robot design options. To begin thinking about how these complex machines move, we need to look to physics, science, math and engineering.
One of the primary components used in robotic automation is the actuator, which converts stored energy into movement. Most actuators are electric motors (brushed and brushless DC motors, to be exact), although chemical and compressed air actuators exist as well. Stepper motors rotate in easy-to-control motions, commanded by a controller rather than a sensor. Piezo or Ultrasonic motors use rapidly vibrating piezo-ceramic elements, which ultimately cause motion. Air muscles work with compressed air, behaving similarly to human muscles which contract and expand. Elastic nanotubes are in experimental stages right now but appear promising, holding high levels of stored energy.
Locomotion is a key component of robotics and automation. Some prototypes roll on one to four wheels. For instance, NASA's "Robonaut" and "Urbie," Carnegie Mellon University's "Ballbot," not to mention characters like George Lucas's "R2D2" and The Jetson's "Rosie," all roll around. However, several robots like Honda's "ASIMO," can walk. The Anybot "Dexter Robot" can jump and MIT Leg Laboratory has developed complex robots that can trot, run, pace and bound. Even still, some robots, like those used in the military, are best suited for flight. Snaking motion robots have been used to save construction workers who were buried in a wreck. Essex University devised robotic fish for research purposes too. There is a place for every type of locomotion in industrial robotics.
For some, human interaction is the end-all and be-all of robotics and automation. At Disney World, the "Imagineers" developed singing, blinking, winking, emotional robots that almost seem like real people. Researchers say that the future of robots is the ability to communicate with humans through facial expressions, speech and gestures, rather than simply on predictable programmed responses. Kismet can create a range of facial expressions, which can help people interact more meaningfully with their companion bots.