Robotics is an integrated study spanning mechanical engineering, electronic engineering, computer engineering and science all at once, and a robot itself is a mechanical device built with electronic circuitry and programmed to perform a specific task. Robots matter most precisely where humans are put at risk -- defusing bombs, searching unstable, collapsed ruins for survivors, and exploring mines and sunken shipwrecks are the standard examples of tasks a robot can take over from a person. A robotic system is built mainly from sensors, power supplies, control systems, manipulators, and the software that coordinates all of them, and at the highest level a robot is usually described as having three main parts: a controller (the 'brain', run by a computer program, which issues commands to the moving parts), the mechanical parts (motors, pistons, grippers, wheels and gears that let the robot physically move, grab, turn and lift), and sensors (which tell the robot about its surroundings -- the sizes and shapes of nearby objects, distances between them, and directions). A more detailed component list breaks this down further: a power conversion unit (batteries, solar power, or hydraulics); actuators, which convert energy into movement, usually rotational or linear; electric motors (AC motor, brushed DC motor, brushless DC motor, geared DC motor) that actuate wheels, arms, fingers, legs, sensors, cameras and even weapon systems; pneumatic air muscles, which contract and expand -- by almost 40% -- when air is pumped in or sucked out, replicating a human muscle; muscle wires, thin strands of shape-memory-alloy wire that contract by about 5% when a current passes through them; piezo motors and ultrasonic motors, used mainly in industrial robots; sensors, which supply real- …