Piezoelectric actuators are simple structures with compact sizes that provide quick and precise responses to an electrical stimulus. The response of the piezoelectric actuator can be a mechanical displacement or a blocking force with the magnitude determined by the structure’s geometry and the electromechanical properties of the materials used. This book presents topical research in the study of piezoelectric actuators. Topics discussed include thick-film piezoelectric actuators prepared by screen-printing; pressure control of vehicle ABS using piezoactuator-based valve modulators; ultrasonic actuators based on the Langevin transducer; the dynamics of hinged-hinged beam using piezoelectric absorbers and modeling and control of piezoelectric actuator systems.