Smart sensors and small robots

Robots are machines that sense, think, act and (more recently) communicate. Sensing, thinking, and communicating have all been greatly miniaturized as a consequence of continuous progress in integrated circuit design and manufacturing technology. More recent progress in MEMS now holds out promise for comparable miniaturization of the heretofore-retarded third member of the sense-think-act-communicate quartet. More speculatively, initial experiments toward microbiological approaches to robotics suggest possibilities for even further miniaturization, perhaps eventually extending down to the molecular level. Alongside smart sensing for robots, with miniaturization of the electromechanical components, i.e., the machinery of robotic manipulation and mobility, we quite naturally acquire the capability of smart sensing by robots. This paper summarizes the state-of-the-art, particularly both respect to the role of and the requirements for sensing. Three main cases are described: (1) the robot's mission is to carry sensors; (2) environmental sensing is required for the robot to accomplish its mission; and (3) proprioception, i.e., sensing for robot self-awareness.