Position, damping and inertia control of parallel-plate electrostatic actuators

A method for controlling position, damping and inertia in parallel-plate electrostatic actuators is proposed. This method overcomes the pull-in effect and the limitations produced by the parasitic capacitances without requiring any additional electrodes or position sensors. It forces the actuator to behave like a linear second-order system with full control of the dynamics, being able to electronically adapt the mass and damping coefficients for a better performance for each particular application. A continuous-time, analog linearization law, feasible to be implemented with typical blocks of analog or digital signal processing, is described and analyzed in this paper.