This project covers the hardware design of a large-format, wide-field imager for the Large Synoptic Survey Telescope (LSST). The imager is in the critical path for the LSST, and may eventually represent a $20 M expenditure. The project covers the investigation of key hardware issues for the imager mosaic module, and will include the following tasks: definition of detector specifications based upon community-defined science requirements; competition for the supply of sample imager modules; engineering of the focal plane array layout and cool substrate; panel analysis of the module performance and estimated cost; and the letting of a contract for two science-grade sample modules, with lab tests. The design process is critical to the eventual development of the wide-field imager, which will have broad impact to the astronomical community as a critical component of the LSST.