Single electrode bidirectional switching of latchable prestressed bistable micromechanical beams

Published

October 1, 2021

Author(s)

Lior Medina, Rivka Gilat, Robert Ilic, Slava Krylov

Abstract

Electrostatically actuated, bistable, curved micromechanical beams can exhibit latching, wherein the beams remain in two distinct stable states without an applied voltage. These structures could serve as building blocks in a variety of applications in areas of micromechanical logic elements, switches, non-volatile memories, and low-power consumption sensors. However, the design of these devices is challenging since such structures are prone to symmetry breaking, which consequently inhibits latching. Generally, the asymmetric responses is circumvented by introducing a tailored axial compressive prestress. In this work we explore, both theoretically and experimentally, the influence of prestress on the single electrode, bidirectional dynamic switching of curved, latchable, single crystal Si $\approx 1000 \;\mu$m long and $\approx 3.5\;\mu$m wide beams. We use Joule heating to apply the necessary prestress required to eliminate symmetry breaking and ensure latching. In accord with the reduced order model predictions, our experimental findings show that the prestress plays a significant role in the dynamic response of the beam. Our results demonstrate bidirectional operation using a single electrode, compact footprint device for tailoring the axial stress and dynamic conditions.

Citation

IEEE Sensors Journal

Volume

21

Issue

19

Pub Type

Journals

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DOI Link

Keywords

Microelectromechanical systems, bistable curved beam, snap-through, latching, electrostatic actuation, bidirectional switching, single electrode actuation, axial stress.

Citation

Medina, L. , Gilat, R. , Ilic, R. and Krylov, S. (2021), Single electrode bidirectional switching of latchable prestressed bistable micromechanical beams, IEEE Sensors Journal, [online], https://doi.org/10.1109/JSEN.2021.3103265 (Accessed October 11, 2024)