TCAD for MEMS
R. Paganini*, R. Ruehl*, J. Funk and H. Baltes Physical Electronics Laboratory, ETH Zurich, Switzerland +Integrated Systems Laboratory, ETH Zurich, Switzerland *ISE AG, Switzerland Introduction. We present key components of a technology CAD (TCAD) tool for inte¬ grated micro electro mechanical system (iMEMS) simulation. The TCAD capabilities augment the SOLIDIS device simulator [1], Key components are: Meshing interface to process simulation; Application-oriented solid modeler; Algorithms for iMEMS sensor and actuator device simulation using finite and boundary element compuational engines; Interface for mixed-signal system level simulation using SPICE. Meshing. We present an approach to boundary-to-mesh generation based on a Monte
Coupled 3D thermo-electro-mechanical simulations of microactuators
We report 3D simulations of microactuators based on the solution of consistently coupled thermo-electro-mechanical equations. The necessary solution algorithms are implemented into the MEMS simulation environment SOLIDIS and allow efficient optimization studies of geometrically complex MEMS devices. Key issues are the solution of coupled equation systems using zone partitioning, adaptive mesh refinement, mesh updating using geometrical algorithms and field smoothing for the extraction of accurate electrostatic forces.
Numerical and experimental investigation on air distributor design of fluidized bed reactor of sawdust pyrolysis
Abstract An improved biomass conversion in a lab-scale fluidized bed reactor (FBR) is achieved by optimizing the air distributor orifice size and number. Two approaches for introducing air were numerically and experimentally examined. These included perforated plate and downward orifice sparger. 3 mm and 5 mm orifice diameters, and 7, 9 and 13 holes were simulated at flow velocities of 2, 4, 6, and 8 times the minimum fluidization velocity, Umf. The simulation results revealed that increasing the orifice number has a positive effect on gas holdup, particularly for the perforated plate, which showed a uniform distribution of bubbles. The sparger configuration produced larger bubbles sizes, which could lead to better recirculation of solid flux, while stagnant particle zones were observed at the lower section of both distributors. A pyrolysis unit is also inserted at the top of freeboard of the FBR. For perforated plate with 6Umf, the pyrolysis process achieved thermal and cold gas efficiencies of 82.91% and 52.03%, respectively, while combustible gases with 41.6%mol CO, 8.7%mol CH 4 and 2.17%mol HC, were obtained. For sparger pipe and 6U mf _sp, 35.33 ppm NOx and 111 ppm SO 2 were measured in flue gas from combustion process at bed region.