The structural diagrams of an electroelastic actuator for nanomechatronic systems on the basis of the generalized piezoelectric effect and taking into account the counter EMF caused by the direct piezoelectric effect are defined. The structural-parametric models of electroelastic actuators for nanomechatronic systems under the conditions of transverse, longitudinal, shear, and generalized piezoelectric effects, and with control using the voltage or current feedback signals are obtained. The structural-parametric model and structural diagrams with feedbacks developed for the electroelastic actuators of nanomechatronic systems reflect the conversion of electrical energy into mechanical energy. The structural-parametric model and structural diagram of an electroelastic actuator are determined depending on the type of its control using the voltage or current feedback signal. The maximal forces and mechanical stresses developed by the piezo actuator of nanomechatronic systems under the conditions of transverse, longitudinal, shear, and generalized piezoelectric effects are determined. The piezo actuator’s elastic compliance and stiffness values under the conditions of transverse, longitudinal, shear, and generalized piezoelectric effects are determined depending on the type of control in a nanomechatronic system: using the voltage or current feedback signal. The transfer functions of piezo actuators under the conditions of transverse, longitudinal, shear, and generalized piezoelectric effects and with control using the voltage or current feedback signal are obtained.