An 8-mm diameter Fiber Robot Positioner for Massive Spectroscopy Surveys
  Massive spectroscopic survey are becoming trendy in astrophysics and
cosmology, as they can address new fundamental knowledge such as Galactic
Archaeology and probe the nature of the mysterious Dark Energy. To enable
massive spectroscopic surveys, new technology are being developed to place
thousands of optical fibers at a given position on a focal plane. These
technology needs to be: 1) accurate, with micrometer positional accuracy; 2)
fast to minimize overhead; 3) robust to minimize failure; and 4) low cost. In
this paper we present the development of a new 8-mm in diameter fiber
positionner robot using two 4mm DC-brushless gearmotors, developed in the
context of the Dark Energy Spectroscopic Instrument. This development was
conducted by a Spanish-Swiss (ES-CH) team led by the Instituto de F\'isica
Te\'orica (UAM-CSIC) and the Laboratoire d'Astrophysique (EPFL), in
collaboration with the AVS company in Spain and the Faulhaber group (MPS &
FAULHABER-MINIMOTOR) in Switzerland.
