Size-dependent analysis and experiments of bulk PMN-PT [001] piezoelectric actuator for MOEMS micro-mirrors

This paper presents the modeling, fabrication, FEM simulation and validation of a PMN-PT [001], bulk micro-actuator intended for integration in smart Micro-Opto-Electrical-Mechanicals Systems (MOEMS). Unlike the majority of piezoelectric materials, PMN-PT [001] has the ability to generate large-stroke out-of-plane actuation; this is due to its high longitudinal piezoelectric coefficient of up to 4500pm/V. After an introduction on MOEMS actuation, a concise modeling is given. The FEM simulations are then presented, highlighting actuation-induced shape specificities. The focus is placed on planar displacement and on possible shape generation. Actuation reached values as high as 680nm for a 200μm thick layer. Spherical shape generation was also studied. After presenting the fabrication of a basic piezo-patch mirror, the experimental verification is provided, outlining the influence of the contact interface size and nature.