  The development of precision cosmology with clusters of galaxies requires
high-angular resolution Sunyaev-Zel'dovich (SZ) observations. As for now,
arcmin resolution SZ observations (e.g. SPT, ACT and Planck) only allowed
detailed studies of the intra cluster medium for low redshift clusters (z<0.2).
With both a wide field of view (6.5 arcmin) and a high angular resolution (17.7
and 11.2 arcsec at 150 and 260 GHz), the NIKA2 camera installed at the IRAM
30-m telescope (Pico Veleta, Spain), will bring valuable information in the
field of SZ imaging of clusters of galaxies. The NIKA2 SZ observation program
will allow us to observe a large sample of clusters (50) at redshifts between
0.4 and 0.9. As a pilot study for NIKA2, several clusters of galaxies have been
observed with the pathfinder, NIKA, at the IRAM 30-m telescope to cover the
various configurations and observation conditions expected for NIKA2.
