MEMS deformable mirrors are showing great promise for use in astronomical adaptive optics systems. Recent
experiments at a Lick Observatory 1-meter telescope have demonstrated a 144 actuator device in a visible
wavelength AO imager. MEMS devices with thousands of actuators could be used for high-Strehl and visible
wavelength AO systems on today's large-aperture telescopes (8-10 meters) and future giant (30 meter) telescopes. In
this paper we present several design concepts for multiple-mirror AO systems and discuss our efforts at the
Laboratory for Adaptive Optics to develop components and test system concepts for these systems.