Nonlinear Dynamics of an Electrically Driven Impact Microactuator

We study the dynamics of an electrostatically driven impact microactuator. Impact between moving elements of the microactuator is modeled using the coefficient of restitution. Friction between the microactuator and its supporting substrate is modeled using the Amonton–Coulomb law. We consider the bifurcations under changes in the driving voltage and frequency. Grazing bifurcations introduce discontinuous transitions between different motions. It is also found that impacts dramatically change the characteristics of the frequency-response curve. Finally, we discuss the evolution of incomplete chatter to complete chatter, that is, sticking.