Automatic System to Measure the Impedance of Piezoelectric Actuators Used in Ultrasonic Scalpels

The aim of this project is to develop an automated system in order to measure electrical impedance of ultrasonic piezoelectric actuators that work at frequencies close to 55 kHz. The main application of this system is related to the control of the operation and the quality of commercial actuators employed in ultrasonic scalpels. The study of the frequency behavior of the actuator through the automatic measurement of the impedance is used to determine failures and aging phenomena. The project refers to a particular type of ultrasonic scalpel made with a “stack” of ring piezoelectric actuators but in general includes also the characterization of piezoelectric actuators with an operating frequency of lower than 500 kHz.