Session: MNS-01-01: Dynamics of MEMS/NEMS 1st Session

Paper Number: 89669

89669 - Bistability Condition for Electrostatically Actuated Initially Curved Micro-Beams in the Presence of Curved Electrodes 

Following an increasing interest in electrostatic actuation of curved beams emanating from curved electrodes. A rigorous limit point analysis is carried out to view how the beam reacts as a function of its geometry, as well as that of the electrode. The culmination of the study is in a bistability condition that describes what geometry a beam and electrode must have in order for a beam for bistability to be present. The study is based on a single-degree-of-freedom (DOF) reduced order (RO) model of a curved beam, derived from Galerkin's decomposition. The extraction of a condition is based on the existence of a vanishing discriminant of a cubic equation, which formed a boundary in a design space of beam and electrode geometries, between mono- and bistability. Such a model and subsequent analysis have been used before for the study of curved beams, especially when it is on the verge of bistability, with a high degree of fidelity. The condition shows that while actuation voltages will increase or decrease as a function of electrode curvature, as well as operational range, the curvature of an electrode plays a key role that cannot be underestimated in the behaviour of a beam. Such results can serve researchers and engineers alike in designing curved beam-electrode configurations for usage in future studies, thus promoting their usage in micro-electro-mechanical (MEMS) based applications.

Presenting Author: Lior Medina Tel-Aviv University

Presenting Author Biography: Received both B.Sc. (2010) and M.Sc. (2012) Magna Cum Laude in mechanical engineering from Tel Aviv University. My M.Sc. thesis was on "Symmetry breaking in electrostatically loaded curved bistable microbeams", conducted under the combined supervision of Prof. Slava Krylov & Prof. Rivka Gilat. In December 2012 I began my Ph.D. studies at the same institution, expanding my studies to the investigation of stability properties in electrostatically operated bistable microdevices. The research was supported by one of the best fellowships in Israel, granted by the Israel Ministry of Science. Further support came from Broadcom and the Israel Science Foundation following successful proposal applications, which I helped to write. In addition, I was also a teaching assistant in seven courses, two of which were for graduate students. On 22 November 2018, I officially obtained my PhD following approval by the university committee and plenum of the senate. With a successful application to the Tel-Aviv Uni. – Northwestern Uni. joint postdoctoral fellowship, I moved to Northwestern University in October 2018 as a postdoctoral fellow, conducting research on Kirigami structures under the guidance of Prof. Espinoza. In October 2019 I have relocated to the University of Cambridge, following a successful application to the Blavatnik postdoctoral fellowship and worked on electrostatically multistable structures under the guidance of Prof. Seshia. In October 2021 I relocated back to Tel Aviv University as a Senior Lecturer.

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