US Patent 7267043 Actuators with diaphragm and methods of operating same

Actuator assemblies comprise an actuator element and two piezoelectric assemblies, with the two piezoelectric assemblies being configured and arranged for controlling movement of the actuator element. In some example implementations, the first piezoelectric assembly and the second piezoelectric assembly are constructed and arranged so that a temperature dependency of the first piezoelectric assembly is cancelled by the temperature dependency of the second piezoelectric assembly. In a first example embodiment, a first piezoelectric assembly comprises a first or main piezoelectric diaphragm connected to the actuator element for displacing the actuator element in response to displacement of the first piezoelectric diaphragm. The first piezoelectric diaphragm and the second piezoelectric diaphragm are fixedly mounted to a movable carriage. In second example embodiment, first variable reservoir having a first piezoelectric diaphragm contracts and a second variable reservoir having a second piezoelectric diaphragm expands during an extension movement of the actuator element, and vise versa during a withdrawal movement of the actuator element.