Fabrication and Characterization of Lateral-Directional Actuator Using Pb(Zr, Ti)O_3 Thin Films

Surface MEMS (microelectromechanical systems), which is fabricated by the micro processing techniques based on thin film deposition and processing, are incorporated into consumer electronics and automobiles. The structures of the surface MEMS having thin shape with small aspect ratio are difficult to drive to the lateral direction. The conventional electrostatic actuators have comb electrodes, resulting in a complex structure. This research addresses on the actuators available to move in a lateral direction by using thin-film Pb(Zr, Ti)O₃. Test cantilevers with two segmented top electrodes on the piezoelectric film are fabricated and the driving characteristics are evaluated. Applications of electrical voltages with reversed phases to the segmented top electrodes at the resonant frequency with lateral oscillation mode moved the cantilever with large displacement of 7 mm. A non-linear effect in the frequency response was also observed for the large applied voltages.