On designing MEMS: A parameterized approach and three-dimensional visual modeling

Current MEMS design practices focus on physical device and process development. Design concepts are implemented in a manual layout. The performance is then analyzed using finite-element tools, usually resulting in time consuming and expensive iterations on both the layout and the underlying process.;To accelerate the design process, a parameterized design methodology is implemented at an abstracted level, analogous to schematic design of circuits. Micromechanical devices are either designed with a physical layout and the lumped-parameters are extracted directly from the layout, or by assembling symbolic representations of microelectromechanical components in MEMS schematic form. Reusable components, such as beam springs, and plate masses, etc. are backed by lumped-parameter models of varying sophistication. Detailed models with second-order effects are used in simulations while simple first-order models are also available for quick analysis. This design methodology frees the designer from doing detailed layout and being concerned about finite-element calculations. It also allows the designer to experiment with new micromechanical architectures and then size components appropriately. The key point is that parameterized design methodology uses reusable component macro-models that can be assembled in different combinations to form a multitude of unique device macro-models, and also simplifies the iterative design loop.;3D visual modeling of MEMS devices is not the primary goal of most MEMS CAD packages. With 3D MEMS, it often requires the designer to imagine and visualize how pieces of initially coplanar structures would eventually have to come off the substrate to fit together in 3D space to form a 3D MEMS system. Exploring the design parameters of how the various coplanar pieces might fit with hand sketches is a cumbersome process. An interactive 3D visual modeling tool is implemented that provides an environment to virtually manipulate pieces within a design. With this 3D MEMS visual modeling tool, design process is expedited for robotic MEMS and MOEM by incorporating collision detection, and ray tracing.