This paper examines the possibility of constructing deformable mirrors for adaptive optics with a large number of degrees of freedom from silicon wafers with bimorph piezoelectric actuation.The mirror may be used on its own, or as a segment of a larger mirror. The typical size of one segment is 100-200 mm; the production process relies on silicon wafers and thick film PZT deposition technology; it is able to lead to an actuation pitch of the order of 5 mm, and the manufacturing costs appear to grow only slowly with the number of degrees of freedom in the adaptive optics.

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Piezoceramic fibers are broadly used for advanced ultrasound transducers and composite sensors and actuators for smart system applications. Different techniques (ALCERU® cellulose spinning technique, extrusion, and polysulfone process) have been developed for fiber fabrication, although there is still an essential need to evaluate the mechanical and electromechanical performance of these fibers. In this study, the microstructure and mechanical properties have been investigated for different fibers fabricated by the three routes. Because of the same sintering program, the fibers showed mainly a similar grain size (1–2 μm) and porosity (2%–6%). A tensile strength up to 72 MPa could be measured for PZT fibers with a diameter of 250 μm produced by the cellulose spinning technique. The Young's modulus varied between 30 and 60 GPa. Stress–strain deformation showed nonlinearity behavior, which could be attributed to ferroelastic domain switching. The threshold for domain switching (proportional limit) of the deformation curve had decreased by increasing the diameter of the fiber. No correlation between fiber processing and proportional limit could be observed.