DETC2002/CIE-xx SUPPORTING DESIGN REFINEMENT IN MEMS DESIGN

ABSTRACT We present a framework to support design refinement during the virtual prototyping of microelectromechanical systems (MEMS). By instantiating MEMS components and connecting them to each other via ports, the designer can both configure complex systems and simulate them. We examine design refinement in the context of ease of use and representation of the virtual prototype. We propose the use of a common, formal grammar representation for the design entities in the virtual prototypeMEMS components, behavioral models and CAD models. We show that the formal grammar approach leads to easy creation of virtual prototypes. In this paper, we focus on portsthe fundamental building blocks of a virtual prototype. Ports mediate all interactions within and between aspects of the virtual prototype. For even moderately complex designs, there can be many interactions present. The representation and organization of all possible ports is important in the context of design refinement. We provide a set-theoretic formalism that defines the algebra of ports. We present a formal grammar for ports that represents a port as a set of attributes, and provide a design refinement mechanism that involves adding or modifying attributes in the port. We illustrate our framework with a MEMS example. We demonstrate that the MEMS designer can evaluate multiple design alternatives quickly and accurately with our framework. KEYWORDS Design methodology, MEMS, Simulation-based design, attribute grammars, port-based modeling, Modelica INTRODUCTION AND MOTIVATION Virtual prototyping can shorten the design cycle of MEMS products by reducing the need for expensive and timeconsuming physical prototyping. The designer can evaluate more design alternatives to obtain a better quality design. In this paper, we propose to support the process of virtual prototyping of multi-disciplinary MEMS systems. We focus our attention on those aspects of virtual prototyping that are particularly important in the context of design refinement. Specifically, we further the current state-of-the-art with respect to representation and ease of use. The system-level design process is usually top-down. The designer begins with a high-level functional description that he decomposes into sub-functions. These sub-functions are assigned to a system architecture as a configuration of components that contain both design specifications and simulation models. When further decomposition or component assignment is not desired, the designer composes the components to create a system-level configuration that is evaluated to verify the function. In this process, there are three recurring themes: composition, or combining subcomponents to create a compound component; reuse, or replacing a componen