A CAE system for micromachines: Its application to electrostatic micro-wobble actuator

This paper describes a new computer-aided engineering (CAE) system for micromachines 10(-6)-10(-3) m in size. An automatic finite-element (FE) mesh-generation technique, which is based on the fuzzy knowledge processing and computational geometry techniques, is incorporated into the system, together with a commercial FE analysis code, MARC, and a commercial solid modeler, DESIGNBASE. The system allows a geometry model of interest to be automatically converted to different FE models, depending on the physical phenomena of the micromachines to be analyzed, i.e., electrostatic analysis, stress analysis, modal analysis, and so on. The FE models are then automatically analyzed using the FE analysis code. Out of the whole process of analysis, the definition of a geometry model, the designation of local node patterns and the assignment of material properties and boundary conditions to the geometry model are the only interactive processes to be done by the user. The interactive operations can be processed in a few minutes. The other processes, which are time consuming and labour intensive in conventional CAE systems, are fully automatically performed in a popular engineering workstation environment. With the aid of multilayer neural networks, the present system also allows us to obtain automatically a design window in which a number of satisfactory design solutions exist in a multi-dimensional design parameter space, considering coupled multiple phenomena such as static and dynamic deformation, thermal conduction, electrostatics, and so on. This CAE system is successfully applied to evaluate an electrostatic micro wobble actuator. As a typical CAE evaluation, we identify the quantitative conditions for operating the micro wobble actuator, considering both structural and electrostatic phenomena.