Helsinki University of Technology – Page 2

Acoustic Impedance Elements Modeling Oscillating Gas Flow in Micro Channels

Veijola T., Helsinki University of Technology, FI

Acoustic impedance models for gas flow in rectangular channels are presented. The models include the effect of slightly rarefied gas (slip-flow region) and the fluid inertia effects. An equivalent circuit is presented that implements the [...]

Compact Model for the Squeezed-Film Damping Including the Open Border Effects

Veijola T., Ruokonen K., Tittonen I., Helsinki University of Technology, FI

A numerical model for the squeezed-film damping between moving rigid, rectangular surfaces is presented. The emphasis is on the nontrivial boundary conditions for the flow, accounting for the finite acoustic impedance of the surrounding gas [...]

Electromechanical Analysis of Micromechanical SOI-Fabricated RF Resonators

Lamminmäki T., Ruokonen K., Tittonen I., Mattila T., Jaakkola O., Oja A., Seppä H., Seppälä P., Seppälä P., Kiihamäki J., Helsinki University of Technology, FI

In this paper, finite element method (FEM) simulations are used to model mechanical properties of MEMS resonators. Using a static displacement analysis the effective spring constant and mass are calculated. Non-linearity of the mechanical restoring [...]

Compact Damping Models for Lateral Structures Including Gas Rarefaction Effects

Veijola T., Helsinki University of Technology, FI

Compact models for the viscous damping coefficient in narrow air gaps between laterally moving structures are reported. The gas rarefaction effects are included in these small-displacement models. In the first part of the paper, a [...]

Compact Large-Displacement Model for Capacitive Accelerometer

Veijola T., Kuisma H., Lahdenperä J., Helsinki University of Technology, FI

A compact large-displacement model for a gas damped capacitive accelerometer is presented. The gas-film model has been derived from the modified nonlinear Reynolds equation, where the in uence of the gas rarefaction is included. The [...]

Dynamic Modelling and Simulation of Microelectromechanical Devices with a Circuit Simulation Program

Veijola T., Kuisma H., Lahdenperä J., Helsinki University of Technology, FI

Simulation blocks of micromechanical sensors and actuators modelling their dynamic electromechanical and fluidic operation are presented. Due to the electrical equivalent circuit realization the sensor system simulations in the frequency and time domains are possible. [...]