Piezoelectricity is an extremely important physical phenomenon and in ceramic form has been widely used in sensors, actuators, and transducers. Piezoelectric thin film applications have been limited in the past with a majority of efforts emphasizing lower performance materials such as ZnO and AlN because of their ability to be easily integrated with standard microelectronics fabrication. However, a special class of functional materials, ferroelectrics, possesses a tremendous potential in new MEMS devices and has seen increasing research interest in recent years. Of particular interest is the use of lead zirconate titanate (PZT) thin films for actuators. Recently, PZT actuators have been successfully integrated to yield RF MEMS switches capable of operating at less than 10 volts.