The MIT Media Lab's "Flying Pantograph" is a pen-wielding tele-robot controlled by a drawing interface. From MIT's Fluid Interfaces research group:
A drone becomes an “expression agent” - modified to carry a pen and be controlled by human motions, then carries out the actual process of drawing on a vertical wall. Not only mechanically extending a human artist, the drone plays a crucial part of the expression as its own motion dynamics and software intelligence add new visual language to the art. This agency forms a strong link between a human artist and the canvas, however, in the same time, is a deliberate programmatic disconnect that offers space for exploiting machine aesthetics as a core expression medium.