Viacheslav Krylov

Solitary waves in an elastic string

Abstract It is well known that a genuinely nonlinear straight string can support only trivial, constant stretch, traveling waves. We demonstrate that such a string preshaped into a rotating helix supports the propagation of subsonic solitons for any stress-strain relation. The properties of the resulting solitary wave depend on its sense of rotation versus the rotation of the free string as a rigid body. The cases of linear and quadratic stress-strain relations are considered explicitly.

Long travel parallel plate electrostatic actuator

We report on a novel long travel actuator architecture based on a folded suspension with an actuating force applied along initially curved suspension beams also used as motion amplifiers. The straightening of the beams is transformed into the lateral motion of the actuator. Combination of stiffening type mechanical and softening type electrostatic nonlinearities leads to the voltage-displacement dependence of the saturation type. The hierarchy of models includes an exact extensible elastica description and reduced order models. Actuators of various configurations were fabricated using SOI technology. The comparison between the experimental and model results reveals good agreement between the two.

Bouncing Mode Electrostatically Actuated Scanning Micromirror for Laser Display Applications

In laser display applications, the necessity to create images free of distortions imposes specific requirements on the motion of scanning devices. We present an approach of a scanning micromirror operation that is aimed to fulfill the requirements of motion linearity, high operational frequency and low actuation voltages. The operational mode incorporates a contact event between the mirror and an elastic constraint followed by a bouncing event and a subsequent inversion of motion. A stable limit cycle with voltage-dependent frequency and triangular response signal is obtained by the application of an actuation voltage which is piecewise constant in time. Approximate expressions relating the frequency and amplitude of the response with the actuating voltage are obtained by energy balance method. The influence of contact losses on the response as well as the stability of the limit cycle are studied numerically.Copyright