WHAT AM I?

I'm a robot that climbs vertical smooth surfaces by attaching suction cups to the surface, then rotating one cup about the other to propel myself in a chosen direction. Cup suction is achieved by independent control of two vacuum pumps attached to release valves and servo motors are responsible for the orientation of my cups relative to the surface. Rotation is achieved by actuating the servo motor attached to the cup with suction, the free cup is then rotated in the desired direction of movement.