Non-linear analysis of FG beam-based double-movable-electrode MEMS

The objective of the present paper is to investigate the static and dynamic responses of geometric non-linear micro-beams, which are made of functionally graded materials, in double-movable-electrode micro-electro-mechanical systems (MEMS). To do so, employing the non-linear strain-displacement relation in such structures based on the von Kármán theory, the governing equations of motion have been obtained by Hamilton’s principle and then solved through the Galerkin weighted residual method. The static and dynamic findings of the present work have been verified by those available in the literature for single-movable-electrode systems. The present static and dynamic results for double-movable-electrode systems have also been compared and successfully validated by those obtained through 3-D finite element simulations carried out in COMSOL commercial software. At the rest of the paper, aside from the influence of the movability of both electrodes, the inertia and material graduation effects on the non-linear response of the system have been investigated. The results reveal that the movability of both electrodes drastically reduces the pull-in voltage of the system.