An electrostatic torsion micromirror is designed using the optimized spring-shaped torsion beams and U-shaped groove supporters. The main advantages of this design will be a reduction in the pull-in voltage for low-voltage applications and the function as a switch of the instability mode by adjusting the effective bending stiffness of the torsion beam. In this design, a theoretical model is dev...

In this paper, we study the operation of electrostatically actuated electromechanical resonators having fractal electrodes. Using the spring-mass model, we establish the scaling relationships for pull-in instability , voltage dependent resonance frequency 1 , and pull-in voltage , where is the fractal dimension of the electrode, is the air-gap, and are the resonance frequency at zero and applie...

In this paper, dynamic behavior of a functionally graded cantilever micro-beam and its pull-in instability, subjected to simultaneous effects of a thermal moment and nonlinear electrostatic pressure, has been studied. It has been assumed that the top surface is made of pure metal and the bottom surface from a metal–ceramic mixture. The ceramic constituent percent of the bottom surface ranges fr...

Electrostatic micro-electro-mechanical system (MEMS) is a special branch with a wide range of applications in sensing and actuating devices in MEMS. This paper provides a survey and analysis of the electrostatic force of importance in MEMS, its physical model, scaling effect, stability, nonlinearity and reliability in detail. It is necessary to understand the effects of electrostatic forces in ...

The dynamic instability regions of composite laminated skew flat plates subjected to uniform in-plane axial end-loading are investigated. The in-plane loading is assumed as a combination of a time-invariant component and a harmonic time-varying component uniformly distributed along two opposite panel ends’ width. In case of some loading frequency-amplitude pair-conditions, the model is subjecte...

We analyze pull-in instability of electrostatically actuated microelectromechanical systems, and study changes in pull-in parameters due to the Casimir effect. When the size of the device is reduced, the magnitude of the Casimir force is comparable with that of the Coulomb force and it significantly alters pull-in parameters. We model the deformable conductor as an elastic membrane and consider...

Background and Objectives: Among the foot orthoses prescribed to improve postural control in chronic ankle instability, foot orthoses designed to affect both types of mechanical and functional instability have a limited research background. In the present study, a type of foot orthosis named the custom mold with a raised ridge around the perimeter was designed, and manufactured, and its effect ...

In this study, a realistic model for dynamic instability of embedded single-walled nanotubes (SWCNTs) conveying pulsating fluid is presented considering the viscoelastic property of the nanotubes using Kelvin–Voigt model. SWCNTs are placed in longitudinal magnetic fields and modeled by sinusoidal shear deformation beam theory (SSDBT) as well as modified couple stress theory. The effect of slip ...