Helsinki University of Technology

Large area optimized thin film nano solar cells on metal sheets

Toivola M., Peltola T., Miettunen K., Halme J., Aitola K., Lund P.D., Helsinki University of Technology, FI

We have upscaled stainless steel based dye-sensitized solar cell (DSC) from small, 0.32 cm2 active area laboratory sized test cells to 6 cm x 6 cm large area ”minimodule”. This is a continuation to our [...]

Large area optimized thin film nano solar cells on metal sheets

Toivola M., Peltola T., Miettunen K., Halme J., Aitola K., Lund P.D., Helsinki University of Technology, FI

We have upscaled stainless steel based dye-sensitized solar cell (DSC) from small, 0.32 cm2 active area laboratory sized test cells to 6 cm x 6 cm large area ”minimodule”. This is a continuation to our [...]

Synthesis and Characterization of Silver Nanoparticle Rings Embedded in Glass

Chen Y., Jaakola J., Ge Y., Säynätjoki A., Tervonen A., Hannula S-P, Honkanen S., Helsinki University of Technology, FI

Ion exchange technique with photolithography-patterned metal mask is used to form silver nanoparticle patterns embedded in glass. Optical transmission measurement is performed to characterize the optical properties of silver nanoparticles. Atomic force microscopy (AFM) of [...]

Thin nanostructured solar cells on metal sheets

Toivola M., Miettunen K., Halme J., Lund P., Helsinki University of Technology, FI

We have studied direct integration of nanostructured, dye-sensitized solar cells (DSC) on industrial sheet metals, used e.g. as building materials. To demonstrate an all-flexible, roll-to-roll producable and mechanically stable DSC, counter electrodes made of platinized [...]

Analytic Damping Model for a Square Perforation Cell

Veijola T., Helsinki University of Technology, FI

A compact model for a square perforation cell is derived. It is generated both analytically and with 3D FEM simulations of the structure. The model consists of six flow resistances, whose values are simple functions [...]

A Method for Solving Arbitrary MEMS Perforation Problems with Edge and Rare Gas Effects

Veijola T., Helsinki University of Technology, FI

We present an accurate and fast method solving arbitrary perforation problems utilizing a solver for an extended modified Reynolds equation, the Local Impedance Reynolds (LIR) solver. The extension includes an additional term in the Reynolds [...]

Extending the Validity of Existing Squeezed-Film Damper Models with Elongations of Surface Dimensions

Veijola T., Pursula A., Helsinki University of Technology, FI

Border flow effects in squeezed-film dampers having a gap separation comparable with the surface dimensions are studied with 2D and 3D FEM simulations and with analytic models derived from the linearized Reynolds equation for small [...]

Model for Flow Resistance of a Rare Gas Accounting for Surface Roughness

Veijola T., Helsinki University of Technology, FI

The contribution of surface roughness is included in the flow resistance of rare gas flow channels. The statistical properties of the surface are taken into account in the model applying a novel approximation for the [...]

Static Equivalent Circuit Model for a Capacitive MEMS RF Switch

Tinttunen T., Veijola T., Nieminen H., Ermolov V., Ryhanen T., Helsinki University of Technology, FI

A simulation model for static analysis of a doubly supported capacitive MEMS RF switch has been constructed using electrical equivalencies. Energy-conserving large-displacement macro models for beam deflection, gap capacitance, electrostatic force, and mechanical contact are [...]

End Effects of Rare Gas Flow in Short Channels and in Squeezed-Film Dampers

Veijola T., Helsinki University of Technology, FI

Simple approximate design formulas (+-5%) for calculating the elongation of the idealized viscous flow channel of rare gas at Knudsen numbers Kn < 100 due to the open end effects. Rectangular channels with a large [...]