This paper describes a novel robotic assembly station, named Sixtiff, which has been conceived and realized at the Swiss Institute of Technology (EPFL) in Lausanne, Switzerland. This station was developed in order td actively assemble micro-optical devices with high accuracy along six degrees of freedom. This novel robotic system is a hybrid serial-parallel structure with six degrees of-freedom. The system is very stiff and since it is not affected by any floating, it is able to guarantee high movement accuracy (linear resolution of 0.25 mu m, and angular resolution of 1.7 mu rad). The robot was used to collimate a laser beam with a Doric lens (cylindrical lens with a diameter of 60 mu m and a focal of 45 mu m). The distance between the emitting area of the diode and the lens is about 10 mu m and the alignment was adjusted with an accuracy of 0.5 mu m.