  Amorphous to crystalline phase transitions in phase change materials (PCM)
can have strong influence on the actuation of microelectromechanical systems
under the influence of Casimir forces. Indeed, the bifurcation curves of the
stationary equilibrium points and the corresponding phase portraits of the
actuation dynamics between gold and AIST PCM, where an increase of the Casimir
force of up ~25% has been measured upon crystallization, show strong
sensitivity to changes of the Casimir force as the stiffness of the actuating
component decreases and/or the effective interaction area of the Casimir force
increases, which can also lead to stiction. However, introduction of intrinsic
energy dissipation (associated with a finite quality factor of the actuating
system) can prevent stiction by driving the system to attenuated motion towards
stable equilibrium depending on the PCM state and the system quality factor.
