Potential electric-field-induced softening mechanism of cantilever stiffness

Ascertain whether exposure of aluminum 5056 cantilever surfaces to electric fields can induce any weakening of their elastic constant and, if such a mechanism exists, characterize and quantify its effect under the operating conditions of the reported resonant capacitive transducers.

Background

To explain the anomalous frequency tuning, the authors consider whether the mechanical stiffness of the six cantilever arms supporting the resonator might decrease under applied electric fields. They note that the cantilevers are situated millimeters from the charged plate (greatly reducing field exposure) and perform estimates showing negligible electrostriction effects.

While they ultimately conclude the influence is virtually null under their conditions, they explicitly state that they do not know of any mechanism that would produce such a softening, leaving the existence of any relevant mechanism as an unresolved point.