Active damping with piezoelectric MEMS devices

Thick PZT films are of major interest in the actuation of mechanical structures. One of the promising fields deals with active damping. Piezoelectric actuators have proved to be effective control devices for active stabilization of structural vibrations and are now used in a wide range of engineering applications. Piezo materials can be integrated in various structural components as distributed sensors or actuators. In this context, Micro-ElectroMechanical Systems appear very attractive in improving the mechanical efficiency of structural active control. These systems can be distributed on a structure and are very powerful since it induces a very high level of stress density. They can effectively present a good opportunity in a large class of problem. The studied micro controlling system is a micro beam totally covered by a piezoelectric, PZT, film. This sample system can be considered as a suspension element being able to support very light and sensitive systems like frequency generator or MEMS sensors. We first describe modeling and the experimental updating methods used to characterize piezoelectric behavior. Secondly, we show the observations highlighting the efficiency of hard-PZT thick films in active damping of sensitive devices by using pseudo direct velocity feedback.