A piezoelectric micro-actuator with three dimensional structure and its micro-fabrication

Piezoelectric micro actuators and motors are promising for the applications in various servo control systems, with the potential to provide ultra-precision positioning and compensation. In this paper, a micro-actuator, which is configured with an "H-shaped" cavity and a pair of high-aspect-ratio parallel beams, was designed. The micro-actuator with the three dimensional structure is capable of providing in-plane flexibility and out-of-plane stiffness. Appropriate materials processing and batch micro-fabrication schemes were developed to produce the piezoelectric micro-actuator prototypes, involving silicon micro machining, wafer bonding, and integration of piezoelectric thin films. The performance evaluation of the obtained micro-actuator samples was also conducted. The results demonstrate that a combination of silicon micro fabrication and piezoelectric thin films is a viable approach to develop miniaturized piezoelectric devices with a complex structure.