FI – Page 4 – TechConnect Briefs

Model of Photovoltage Response of Bacteriorhodopsin in PVA Films

Frydrych M., Lensu L., Aschi C., Parkkinen J., Parkkinen S., Parkkinen J., Parkkinen S., Jaaskelainen T., Lappeenranta University of Technology, FI

Bacteriorhodopsin (BR) is a light-transducing protein contained in a purple membrane of microorganism Halobacterium salinarium. Natural function of BR is to act as a light-driven proton pump in energy balancing mechanism of the bacterium. Numerous [...]

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 [...]

Analytic and Raytrace Modeling of a Miniaturized Infrared Spectrometer Module

Keränena K., Blomberg M., Tenhunena J., Kariojac P., VTT Electronics, FI

When designing the construction of an optoelectronic module, the modeling of the system allows for the possibility to optimize geometries, materials and components in order to achieve optimal performance and cost effectiveness for the final [...]

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 [...]

Strength of Nanoscale Copper Connection Under Shear

Heino P., Tampere University of Technology, FI

Strength and shear modulus of several polycrystalline copper systems were calculated with the molecular dynamics method and effective-medium potential. Grain size varied between 2{10nm and systems were sheared beyond the yield point at room temperature. [...]

Molecular Dynamics Study of Thermally Induced Shear Strain in Nanoscale Copper

Heino P., Ristolainen E., Tampere University of Technology, FI

We study the effects of thermally induced shear strain and stress in several nanoscale copper systems consisting of about 200k atoms with the effective-medium theory and molecular dynamics method. Both edge and screw dislocations are [...]

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. [...]