Design and optimization of piezoelectric dual-mode micro-mirror

Abstract

MEMS micro-mirrors have been widely used in optical communication, projection display, and microscanner, etc. Various MEMS micro-mirror devices have been reported. In this paper, the design of a bulk-micromachined MEMS piezoelectric dual-mode micro-mirror is proposed. The working principle of the dual-mode micro-mirror device is analyzed. Based on the analysis, a set of optimized design parameters of the micro-mirror is suggested. Theoretical analysis shows that the proposed micro-mirror can deflect for a maximum displacement of 2.5μm in its piston mode, and tilt for a maximum angle of 4.88° in its torsional mode. The fabrication flow of the MEMS micro-mirror is also suggested. The proposed micro-mirror has the advantages of large displacement and large tilt angle due to piezoelectric activation. The PZT actuated micro-mirror (PAM) also leads to improved linearity in tilting angle and piston displacement. Further, fast response of the PZT unimorph on the applied actuation voltage ensures wider operation bandwidth of the PAM in contrast to thermal activated micro-mirrors. © Springer Science+Business Media B.V. 2010.