Investigation of dynamic instability of three plates switch under step DC voltage actuation using modified couple stress theory

Abstract

In this paper dynamical instability of three-layer micro-switch under DC voltage actuation has been studied. Recent studies have used the classical beam theory while leaving out the length scale parameter. In this paper dynamic behavior of the switch has been investigated based on couple stress theory and considering the length scale parameter. To this end, governing dynamic equation of the micro switch has been extracted and presented. Considering the nonlinearity of governing equation due to the existence of electrostatic force, Galerkin method has been implemented to overcome this nonlinearity and solve the mentioned equation and obtain the dynamic response. Dynamic response of micro switch has been investigated with and without considering the damping effects. Variation of dynamic pull-in voltage versus micro beam length and primary gap between micro beam and stationary electrodes have been studied using couple stress and classic beam theory and obtained results have been compared to each other. Also dependency of dynamic pull-in voltage to damping factor has been studied with considering two theories. Furthermore switching time of micro switch have been determined and compared using couple stress and classic beam theories.

Free vibration of microscale frameworks using modified couple stress and a combination of Rayleigh–Love and Timoshenko theories

“…On the one hand, there are investigations with objectives associated with the analyses of standalone micro-structures, for instance, microbeams with mechanical loads (Dehrouyeh-Semnani and Nikkhah-Bahrami, 2015; Park and Gao, 2006; Şimşek, 2010), microbeams under electromechanical loads (Abdi et al, 2011; Attia and Emam, 2018; Fakhrabadi and Yang, 2015), thermo-electro-mechanical loading (Jia et al, 2018), geometrically nonlinear behaviour of microbeams (Dai et al, 2015; Ghayesh and Farajpour, 2018; Sedighi et al, 2014), piezoelectric microbeams (Ansari et al, 2014; Tan and Chen, 2019), composite laminated beams (Chen and Li, 2013), microplates (Farokhi and Ghayesh, 2015; Kim et al, 2019; Zandekarimi et al, 2018) and microshells (Jouneghani et al, 2018; Zeighampour and Beni, 2015). On the other hand, the MCST has also been applied to integrated microscale systems (Fard et al, 2018; Mustapha and Ruan, 2015). Furthermore, the study by Li et al (2018) presented a standard experimental procedure for determining the material length scale of the MCST.…”

Multi input versus single input sliding mode for closed-loop control of capacitive micro structures

“…As it was shown, using closed loop control, we were able to reduce the relative electrodes distance to 0.85 of initial distance, without any instability occurring. But according to the references [31][32][33][34][35][36][37][38][39] using open loop control, this distance can only be reduced to about 0.33 times of the initial gap of the two electrodes. This condition also occurs for nanostructures that have been stimulated by electrostatic force [38,43].…”

“…As presented in refs. [36][37][38][39], this singularity does not occur at x 1 = 1 , but occurs around x 1 = 0.33 and before reaching to x 1 = 1 , for common capacitive micro even nano structures. For capacitive microstructures with two conductive plates (like the microstructure of this paper) the instability gap is variable and it isn't fixed on x 1 = 0.33 , but also this instability distance never reaches to x 1 = 1 or x 1 = −1 [31,39].…”

Pull in Analysis of Nano sized RF switches using Artificial Neural Networks

“…Dynamic and static analysis of pull-down voltage for CNT switches such as fixed-fixed and cantilever switches that are suspended on a ground plane made of graphene has also been reported for radio frequency applications [11,12] paving the pathway for developing rapid and reconfigurable microwave circuitry. One of the major parameters observed in the majority of MEMS/NEMS structures is the pull-down voltage instability and copious research have been done in this area using different numerical approaches [13]. Numerical analysis for different MEMS/NEMS structures in the determination of pull-down voltage was analysed [14,15].…”