arXiv subjects

V. V. Loboda

Publications and source records attributed to V. V. Loboda.

5 recordsLinked to original sources

arXiv2026

Role of the Casimir force in the capacitive radio-frequency microelectromechanical switches

We determine the role of the fluctuation-induced Casimir force acting between a membrane of cylindrical shape and a bottom electrode in microelectromechanical capacitive switches. For this purpose, the Casimir force is computed taking into account the real properties of both a membrane and a bottom electrode materials with account of surface roughness. The obtained results are compared with those found for the smooth surfaces using the idealization of ideal metal. It is shown that an account of both the real material properties and surface roughness is crucial for obtaining the correct values of the Casimir force. According to our results, at the shortest separations, when the switch membrane is in contact with the transmission line, the magnitudes of the Casimir force may exceed the magnitudes of the electric one depending on the value of the operating voltage. The obtained values of the Casimir force can be used for determining the thickness of the switch membrane, which ensures the necessary magnitude of the restoring elastic force required for a stable cyclic functioning of the micromechanical switch with no pull-in.

cond-mat.mes-hall↗

arXiv2025

An interface crack in 1d piezoelectric quasicrystal under antiplane mechanical loading and electric field

The present study provides the consideration of a mode III interface crack in one-dimentional (1D) piezoelectric quasicrystal under antiplane phonon and phason loading and inplane electric field. Due to complex function approach all required electromechanical parameters are presented through vector-functions analytic in the whole complex plane except the crack region. The cases of electrically impermeable (insulated) and electrically limited permeable conditions on the crack faces are considered. In the first case a vector Hilbert problem in the complex plane is formulated and solved exactly and in the second one the quadratic equation with respect to the electric flux through the crack region is obtained additionally. Its solution permits to find phonon and phason stresses, displacement jumps (sliding) and also electric characteristics along the material interface. Analytical formulas are also obtained for the corresponding stress intensity factors related to each field. The numerical computations for three selected variants of the loading conditions was conducted and the resulting field distributions are visualised on the crack continuation beyond the crack and also inside of the crack region.

cond-mat.mtrl-sci↗

arXiv2025

Impact of surface roughness on the stability of nanoelectromechanical pressure sensors in the Casimir regime

The stability of nanoelectromechanical pressure sensors working in the Casimir regime is considered with account of surface roughness on both the sensor membrane and the ground plate. The equilibrium positions of the sensor membrane are found from the balance between the external measured, elastic, electric pressures, and the Casimir pressure computed by means of the Lifshitz theory. It is shown that the stable equilibrium position of the sensor membrane is nearly independent of the surface roughness, whereas its unstable equilibrium position is shifted to larger membrane-plate separations. The use of these results for creatign pressure sensors with further shrinked dimensions is discussed.

quant-ph↗

arXiv2024

Pull-in features of nanoswitches in the Casimir regime with account of contact repulsion

The cantilever tip of a nanoswitch in close proximity to the ground plate is considered with account of electrostatic, elastic, van der Waals (Casimir), and also contact repulsive forces. The van der Waals (Casimir) and contact repulsive forces are computed for a Si cantilever and either Au or Ni ground plates using the Lifshitz theory and the method of pairwise summation with account of surface roughness. It is shown that at short separations an impact of the van der Waals (Casimir) force leads to the pull-in and collapse of a cantilever onto the ground plate if the contact repulsion is disregarded. Taking into consideration contact repulsion, the nanoswitch is demonstrated to have the stable cyclic behavior with no pull-in when switching voltage on and off.

cond-mat.mes-hall↗

arXiv2024

Role of the Casimir force in micro- and nanoelectromechanical pressure sensors

The Casimir force caused by the electromagnetic fluctuations is computed in the configurations of micro- and nanoelectromechanical pressuresensors using Si membranes and either Si or Au-coated Si substrates. It is shown that if, under the influence of external pressure, the membrane-substrate separation drops to below 100 nm, the Casimir force makes a profound effect onthe sensor functioning. There exists the maximum value of external pressure depending on the sensor parameters such that it finds itself in a state of unstable equilibrium. For this and larger pressures, the Casimir force leads to a collapse of the sensor, which loses its functionality. For any smaller external pressures, there exist two equilibrium positions, one of which is unstable and another one is stable, at smaller and larger membrane-substrate separations, respectively. The latter can be safely used for the pressure measurements. Possible applications of the {obtained} results in the design of micro- and nanoelectromechanical pressure sensors of next generations with further decreased dimensions are discussed.

cond-mat.mes-hall↗