Visual modeling and design of microelectromechanical system transducers

Abstract Microelectromechanical systems (MEMS) integrate miniaturized mechanical structures with electronics to extend the benefits of planar integrated circuit technology to a broader class of systems, involving sensors, actuators, filters, resonators, switches, and wave guides. The mechanical structures, such as beams, plates, groves, and diaphragms, implement transduction between energy domains, passive implementations of discrete electrical devices, and conduction paths for electromagnetic radiation [F. Frank, J. Staller, The merging of micromachining and microelectronics, Third International Forum on ASIC and Transducer Technology, Alberta, Canada, May 1990, pp. 53–60, R. Howe, Silicon micromechanics: sensors and actuators in a chip, IEEE Spectrum, July (1990) 29–35]. To realize the potential and growth of microelectromechanical systems (MEMS) technology, many new design and manufacturing challenges must be addressed. The close proximity of the integration of mechanical and electrical domains within the small dimensions associated with very large scale integration (VLSI) presents new energy-coupling issues. The behavior of the overall system is not the simple concatenation of separate mechanical and electrical behaviors, but the simultaneous combination of the mechanical and electrical behaviors. New modeling, analysis, and design techniques are required to address both mechanics and electronics. In this paper, we address initial design capture and system conceptualization of MEMS transducers based on visual modeling and design. Visual modeling frames the task of generating hardware description language (analog and digital) component models in a manner similar to the task of generating software programming language applications. A domain is created using relevant artifacts and the artifacts are rendered to highlight key design aspects. The artifacts may be directly manipulated in controlled ways to alter design aspects—a process we refer to as design - by - direct - manipulation . To facilitate the application of visual modeling and design for microelectromechanical transducers, artifacts, renderings, and associated design aspects need to be largely predefined. This requirement leads to a structured topological design strategy wherein microelectromechanical foundry cell libraries are utilized. Microelectromechanical system transducer design becomes a process of exploring candidate cells (topologies), varying key aspects of the transduction for each topology, and determining which topology best satisfies design requirements. Design renderings and aspects emphasize a circuit level of abstraction. Coupled-energy MEMS characterizations are presented based on branch constitutive relations and an overall system of simultaneous differential and algebraic equations (DAE). The resulting design methodology is called Visual Integrated-Microelectromechanical VHDL-AMS Interactive Design (VIVID).