Abstract: This disclosure provides systems, methods and apparatus for controlling a mechanical layer. In one aspect, an electromechanical systems device includes a substrate and a mechanical layer positioned over the substrate to define a gap. The mechanical layer is movable in the gap between an actuated position and a relaxed position, and includes a mirror layer, a cap layer, and a dielectric layer disposed between the mirror layer and the cap layer. The mechanical layer is configured to have a curvature in a direction away from the substrate when the mechanical layer is in the relaxed position. In some implementations, the mechanical layer can be formed to have a positive stress gradient directed toward the substrate that can direct the curvature of the mechanical layer upward when the sacrificial layer is removed.