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micromotors can be straightforwardly fabricated and this will enable their wide applications as microac-
tuators and microsensors. However, the axial micromotors must be designed and optimized to attain good
performance. The optimization is based upon electromagnetic, mechanical, and thermal design. The
micromotor optimization can be carried out using the steady-state concept (finite element analysis) and
dynamic paradigms (lumped-parameters models or complete electromagnetic-mechanical-thermal high-
fidelity mathematical models derived as a set of partial differential equations using Maxwell’s, torsional-
mechanical, and heat equations). In general, the nonlinear optimization problems are needed to be
addressed, formulated, and solved to guarantee the superior microtransducer performance. In addition
to the microtransducer design, one must concentrate the attention on the ICs and controller design. In
particular, the circuitry is designed based upon the converter and inverter topologies (e.g., hard- and soft-
switching, one-, two-, or four-quadrant, etc.), filters and sensors used, rated voltage and current, etc. From
the control prespective, the electromagnetic features must be thoroughly examined. For example, the
electromagnetic micromotor studied is the synchronous micromachine. Therefore, to develop the elec-
tromagnetic torque, the voltages applied to the stator windings must be supplied as the functions of the
rotor angular displacement. Therefore, the Hall-effect sensors must be used, or the so-called sensorless
controllers (the rotor position is observed or estimated using the directly measured variables) must be
designed and implemented using ICs. This brief discussion illustrates a wide spectrum of fundamental
problems involved in the design of integrated microtransducers with controlling and signal processing ICs.

Conclusions
The critical focus themes in MEMS development and implementation are rapid synthesis, design, and
prototyping through synergetic multi-disciplinary system-level research in electromechanics. In partic-
ular, MEMS devising, modeling, simulation, analysis, design and optimization, which is relevant to
cognitive study, classification, and synthesis must be performed. As microtransducers and MEMS are
devised, the fabrication techniques and processes are developed and carried out. Devising microtrans-
ducers is the closed evolutionary process to study possible system-level evolutions based upon synergetic
integration of microscale structures and devices in the unified functional core. The ability to devise and
optimize microtransducers to a large extent depends on the validity and integrity of mathematical models.
Therefore, mathematical models for different microtransducers were derived and analyzed. It is docu-
mented that microtransducer modeling, analysis, simulation, and design must be based on reliable
mathematical models which integrate nonlinear electromagnetic features. It is important to emphasize
that the secondary phenomena and effects, usually neglected in conventional miniscale electromechanical
motion devices (modeled using lamped-parameter models and analyzed using finite element analysis
techniques) cannot be ignored. The fabrication processes were described to make high-performance
microtransducers.

References
1. Campbell, S. A., The Science and Engineering of Microelectronic Fabrication, Oxford University Press,
New York, 2001.
2. Lyshevski, S. E., Nano- and Micro-Electromechanical Systems: Fundamental of Micro- and Nano-
Engineering, CRC Press, Boca Raton, FL, 2000.
3. Lyshevski, S. E., MEMS and NEMS: Systems, Devices, and Structures, CRC Press, Boca Raton, FL, 2001.
4. Madou, M., Fundamentals of Microfabrication, CRC Press, Boca Raton, FL, 1997.
5. Kim, Y.-J. and Allen, M. G., “Surface micromachined solenoid inductors for high frequency appli-
cations,” IEEE Trans. Components, Packaging, and Manufacturing Technology, part C, vol. 21, no. 1,
pp. 26–33, 1998.
6. Park, J. Y. and Allen, M. G., “Integrated electroplated micromachined magnetic devices using low
temperature fabrication processes,” IEEE Trans. Electronics Packaging Manufacturing, vol. 23, no. 1,
pp. 48–55, 2000.

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