Abstract
In this study, we report piezoelectric microactuators composed of Pb(Zr,Ti)O3 (PZT) films for low-voltage RF-MEMS switches. In order to realize a flat beam shape as well as a large displacement, we have adopted an X-shaped connector at the center of the beam. Finite element method (FEM) simulation indicates that the bending motion of the beam is almost same as two connected cantilevers, and the maximum displacement reaches 3.2 μm/5 V. To fabricate the microactuators, piezoelectric PZT films were deposited on Si substrates using rf-sputtering and microfabricated into the PZT/Cr unimorph actuators of 800 μm in length and 200 μm in width, respectively. Although the X-shaped connector effectively releases the stress of the multilayered beam so that the beam shape is almost flat, small residual stress caused slight concave curvature along the width. The displacement at the center of the beam was measured using a laser Doppler vibrometer. The measurement revealed that the displacement was 0.5 μm/5 V which was lower than the FEM result. The reduction of the displacement is attributed to the increase of the stiffness of the beam due to the concave curvature of the beam width.
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References
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Acknowledgments
This study is a part of Kyoto City Collaboration of Regional Entities for the Advancement of Technological Excellence of JST on the basis of research results supported in part by grant-in-aids for Scientific Researches (A) (No.14205037 and No. 15201033) and Center of Excellence for Re-search and Education on Complex Functional Mechanical Systems (COE program) of MEXT, Japan.
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Kanno, I., Tazawa, Y., Suzuki, T. et al. Piezoelectric unimorph miroactuators with X-shaped structure composed of PZT thin films. Microsyst Technol 13, 825–829 (2007). https://doi.org/10.1007/s00542-006-0283-z
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DOI: https://doi.org/10.1007/s00542-006-0283-z