  A common way to analyze electrostatic microelectromechanical systems (MEMS)
actuators is to use their energy-displacement landscape. Here, we describe an
alternative approach to analyze electrostatic MEMS actuators using their
energy-charge landscape. This technique involves coordinate transformation from
displacement to charge, thereby formulating the Hamiltonian of electrostatic
MEMS actuators in terms of charge. We investigate the use of the energy-charge
landscape to analyze static pull-in, dynamic pull-in, and pull-out phenomena.
The voltage expressions derived using this method are identical with those
derived using the conventional energy-displacement landscape. In addition, we
also obtain the expressions for charge under static and dynamic pull-in
conditions. This work can aid in the design and analysis of electrostatic MEMS
devices. As a case study, the analysis of a feedback capacitor-MEMS actuator
system is presented to illustrate the application of the energy-charge
landscape.
