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

Piezoelectric micro-actuators are promising for 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 material 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 micro-actuator was also conducted. The results demonstrate that a combination of silicon micro-fabrication and piezoelectric thin film deposition is a viable approach to produce miniaturized piezoelectric devices with a complex structure.