Structural Modeling and Dynamic Analysis of a Piezoelectric Forceps Actuator

A piezoelectric forceps actuator (PFA) is recently invented for potential use in minimum invasive and non-invasive surgery and diagnosis, and other biomedical applications. This paper is concerned with structural modeling, dynamic analysis, and feedback control of such an actuator. The PFA is modeled as a composite curved beam with laminated piezoelectric layers. The exact open-loop and closed-loop transfer functions of the PFA control system consisting of the curved beam, sensor, actuator and control logic are obtained in exact and closed form without discretization. With the transfer function formulation, the natural frequencies and frequency response of the actuator are then predicted and a simple feedback control law is implemented. The theoretical model of the actuator is validated in experiments.