If one were to apply, for example, 60 Hz AC to a piezoelectric material, would the strain rate be 60 Hz? I am not entirely sure if I am using "strain rate" in its proper sense; I use it merely to describe what I imagine would be the rate at which the material expands and contracts while exposed to an AC source. I assume there is some lag, depending on the material properties... I.e. 60 Hz AC applied would lead to the piezo oscillating at slightly less than 60 Hz. However, I cannot find any information on this and have a very limited knowledge of piezoelectrics. Edit: I forgot to ask: If one were to apply a voltage to a piezoelectric momentarily and then remove the source, at what rate would the piezo return to its natural geometry? Any help would be much appreciated!