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.
Palaeocarpinus (Extinct Betulaceae) from Northwestern China: New Evidence for Paleocene Floristic Continuity between Asia, North America, and Europe
Spiny-bracted fruits of Palaeocarpinus Crane, a genus of Betulaceae previously known only from Europe and North America, have been discovered in the Paleocene of Altai, northwestern China. The fruits are found in association with abundant Corylus-like foliage and staminate catkins containing Corylus-like pollen. Because of problems distinguishing leaves of Corylus from those of extinct betulaceous genera, we place these leaves in the genus Corylites Gardner ex Seward & Holttum. The fruits, staminate catkins, pollen, and leaves from Altai were probably all produced by a single species. Palaeocarpinus orientalis is nearly identical in its morphology to Palaeocarpinus joffrensis from the Paleocene of North America except in the more rounded primary bracts of the associated staminate catkins. The species is less similar to Palaeocarpinus laciniata from the Paleocene of southern England.