The Digital Micromirror DeviceTM (DMDTM) represents a breakthrough in large-scale integrated spatial light modulators. At the heart of each DMD display lies an array of five hundred thousand micromirrors fabricated on a single piece of silicon. Successful operation of the DMD array depends on the robustness, similarity, and reliability of each individual pixel and the ability to control all the pixels over time. This paper describes the challenges facing a pixel design and many of the recent improvements found in the current DMD architecture. Finally, we present the concept of a solution space, which is a measure of the architecture's ability to meet the design objectives.