Bending a thin flat panel on an aerodynamic surface using piezoelectric actuators has been proposed to control phenomena such as flutter, sing divergence and transonic drag. Such smart material applications are not feasible unless actuators can produce larger panel bending deflections than are presently predicted. The objective of this study is to maximize bending deflection of a flat, rectangular panel by attaching a thin piezoelectric actuators to one side of the panel. Two optimization cases are considered: (a) the rectangular actuator is mounted in the center of the panel surface and has area and thickness as design variables; (b) the rectangular actuator is composed of two stacked layers, each having an independent design thickness and area. Studies are presented for different panel aspect ratios for simply supported and clamped (fixed) boundary conditions, and for aluminum and steel host panels. The results show that, for a simply supported aluminum panel with an aspect ratio of 1.5, the best single thickness PZT actuator has a thickness of 0.634 of the host panel and covers 64.7% of the panel. For the two layer stacked actuator, one PZT layer has a thickness ratio of 0.391 and covers 70.6% of the panel, while the other layer has a thickness ratio of 0.313 and covers only 35.7% of the panel. Both of these configurations create nearly identical panel center deflections, but the two layer design weighs slightly less. This study also indicates that formal optimization is a necessary tool for actuator design and that shaped actuators can save weight.