Patent ID: 8552620

Claim:
A mechanical output measurement and evaluation method for a piezoelectric actuator that mechanically expands and contracts to deform in response to applied voltage or electric charge utilizing the piezoelectric effect or the electrostrictive effect, comprising the steps of: finding equivalent circuit constants of the piezoelectric actuator including damping capacity, rigidity, and an electrical to mechanical conversion factor; applying a voltage to the piezoelectric actuator and measuring electrical quantity flowing into the piezoelectric actuator due to the applied voltage, or applying an electric charge to the piezoelectric actuator and measuring voltage applied to the piezoelectric actuator due to the applied electric charge; and measuring and evaluating one or more of force, displacement, or mechanical energy generated by the piezoelectric actuator and applied to a target object, or rigidity of a target object using the equivalent circuit constants, the applied voltage, and the electrical quantity.