Lumped Electro-Thermo-Mechanical Beam Model

A. Chigullapalli
Purdue University, US

Keywords: MEMS, FEA


In this paper we present a lumped electro-thermo-mechanical beam model. Such a model is important for efficiently computing the deflection of an assemblage of mechanical beams that are subject to one or more applied voltages, currents, thermal radiation sources, or energy exchanges between the beams and neighboring components, underlying substrate, or the ambient. Beyond Joule heating, we appear to be the first to report on a lumped MEMS model that also accommodates energy transfer by radiation, convection, and other forms of conduction. We found no such models in the MEMS literature. Our model can be used for both sensing and actuation. When used as a sensor, applied heating from a variety of sources generates a thermal expansion that changes the lumped beam’s geometry and resistance, which can be sensed by a change in current, voltage, or capacitance. When used as an actuator, an applied current or voltage generates a small thermal expansion, which can be magnified to achieve a useful displacement.