Ceramic Actuators: Principles and Applications

Abstract

Piezoelectric and electrostrictive actuators, capable of moving something electromechanically, are forming a new field between electronic and structural ceramics. Application fields are classified into three categories: positioners, motors, and vibration suppressors. The manufacturing precision of optical instruments such as lasers and cameras, and the positioning accuracy for fabricating semiconductor chips, which must be adjusted using solidstate actuators, is of the order of 0.1 μm. Regarding conventional electromagnetic motors, tiny motors smaller than 1 cm3 are often required in office or factory automation equipment and are rather difficult to produce with sufficient energy efficiency. Ultrasonic motors whose efficiency is insensitive to size are superior in the minimotor area. Vibration suppression in space structures and military vehicles using piezoelectric actuators is also a promising technology.New solid-state displacement transducers controlled by temperature (shape memory alloy) or magnetic field (amorphous magnetostrictive alloy) have been proposed, but are generally inferior to the piezoelectric/electrostrictive actuators because of technological trends aimed at reduced driving power and miniaturization.