A proposal of a method to evaluate the electrostrictive material for ultrasonic transducers

The electrostrictive ultrasonic transducers operate under both high mechanical amplitude of vibration and high electric field. So far it has been measured either electrically or mechanically to evaluate electrostrictive materials for the ultrasonic transducers. Both methods cannot possibly justify their full legitimacy, because each does not always represent the actual use of material. We propose applying a new evaluating method of electrostrictive materials for ultrasonic transducers. This introduces the figure of merit A2/r1G1, involving both electrical and mechanical terms [where A is the force factor, r1 the mechanical internal resistance, and G1 the blocked conductance]. The figure of merit depending on the vibration velocity is described for several electrostrictive materials.