Design of a discrete flexure for a SiC deformable mirror with PMN stacked-actuators.

In the present work, a discrete flexure for silicon carbide (SiC) deformable mirror (DM) with Lead-Magnesium-Niobate (PMN) stacked-actuators is designed using topology and size optimizations. In order to fulfill the designated surface strokes of the SiC mirror without adhesive failure, discrete flexures are adopted between the mirror faceplate and the actuators. As the same design process for the flexure of the final DM model, which has a 140 mm diameter mirror faceplate and 489 channels of piezoelectric PMN-30PT single crystal multilayer actuators, the topology and the sizes of the flexure for the 5×5 engineering DM model are optimized. The topology and the size optimizations are conducted by GTAM and DesignXplorer in ANSYS based on finite element method (FEM). The prototype of the designed model is built and the test results show appropriate mirror deformations comparing with the simulated results without adhesive failure.