Low-Voltage-Driven Thin Film PZT Stacked Actuator for RF-MEMS Switches

Abstract

A thin film piezoelectric actuator stacking five PZT (Pb(Zr_0.52,Ti_0.48)O₃) layers has been developed to achieve large displacement and large force at low driving voltage. In this paper, the fabrication process and the operation characteristics of the developed PZT actuator are reported. Each PZT layer of 200nm thickness was deposited by sol-gel method and sandwiched with thin Pt electrodes, which were electrically connected to plus and minus terminals alternately. The displacement-force characteristic of the fabricated actuator shows the maximum displacement of 43µm without load and the estimated maximum contact force of 16µN at a driving voltage of 5V. The developed PZT actuator is applicable to RF-MEMS switches, which need both high contact force and large isolation gap within a limited footprint.