The modeling of electrostatic forces in small electrostatic actuators

Abstract

The basic elements of electrostatic devices (conductors, dielectrics, insulators, electrets, and ferroelectrics) are reviewed and it is shown that the modeling of electrostatic forces is a very different, and in many ways a more difficult, undertaking than the modeling of magnetic interactions; the difference between the real-world behavior of electrostatic configurations and textbook models is much greater than for magnetic configurations. Models must take into account the realities of materials, in particular the fact that resistivity is never infinite, and that any structural part of an actuator will affect fields through its dielectric properties. It is seen that in this sense (the behavior of materials), as well as in the most basic conceptual viewpoint (fields determined by potentials rather than by direct sources), electrostatics and magnetostatics are nearly opposite studies.