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• NODAS v 1.4 [53]. This downloadable tool provides a library of parameterized components
(beams, plate masses, anchors, vertical and horizontal electrostatic comb drives, and horizontal
electrostatic gaps) that can be interconnected to form MEMS systems. The tool outputs parameters
that can be used to perform electromechanical simulations with the Saber simulator [27]. A detailed
example is available at [54], and a description of how the tool works (for v 1.3) is also available [55].
Useful information is also available in [70].

D. “Metatools” Which Attempt to Integrate Two or More Domain-Specific Tools
into One Package
• MEMCAD, currently being supported by the firm Coventor [56]. This product was previously
supported by Microcosm, Inc. It provides low-level simulation capability by integrating domain-
specific FEA tools into one package to support coupled energy domain simulations. It also supports
process simulation. Much of the extensive research underlying this tool is summarized in [57].
• MemsPro [58], which currently incorporates links to ANSYS. MemsPro itself is an offshoot of
Tanner Tools, Inc. [59], which originally produced a version of MAGIC [12] that would run on
PCs. The MemsPro system provides integrated design and simulation capability. Process “design
rules” can be defined by the user. SPICE simulation capability is integrated into the toolset, and
a data file for use with ANSYS can also be generated. MemsPro does not do true energy domain
coupling at this time. Some library components are also available.

E. Other Useful Resources
• The MEMS Clearinghouse website [60]. This website contains links to products, research groups,
and conference information. One useful link is the Material Properties database [61], which
includes results from a wide number of experiments by many different research groups. Informa-
tion from this database can be used for initial “back of the envelope” calculations for component
feasibility, for example.
• The Cronos website [62]. This company provides prototyping and production-level fabrication
for all three process approaches (surface micromachining, bulk micromachining, and high aspect
ratio manufacturing). It is also attempting to build a library of MEMS components for both surface
micromachining (MUMPS, or the Multi-User MEMS Process [63]) and bulk micromachining.

13.5 Modeling and Simulating MEMS, i.e., Systems with Micro-
(or Nano-) Scale Feature Sizes, Mixed Digital (Discrete)
and Analog (Continuous) Input, Output, and Signals,
Two- and Three-Dimensional Phenomena, and Inclusion
and Interaction of Multiple Domains and Technologies

In preceding sections we briefly described the current state-of-the-art in modeling and simulation in
both the digital and analog domains. While the digital tools are much more developed, in both the digital
and analog domains there exist standard, well-characterized technologies, standard widely available tools,
and stable educational and prototyping programs. In the much more complex realm of MEMS, this is
not the case. Let us compare MEMS, point by point, with digital and analog circuits.
• Is there a small set of basic elements? The answer to this question is emphatically no. Various
attempts have been made by researchers to develop a comprehensive basic set of building blocks,
beginning with Petersen’s identification of the fundamental component set consisting of beams,
membranes, holes, grooves, and joints [64]. Most of these efforts focus on adding mechanical and
electromechanical elements. In the SUGAR system, for example, the basic elements are the beam
and the electrostatic gap. In the Carnegie Mellon tool MEMSYN [65], which is supported by the

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