Piezoelectric actuator with multi-function spring and device using same

A piezoelectrically actuated device includes a body, a valve disposed within the body and an actuator for the valve, the actuator including a casing coupled with the body and a piezoelectric element disposed within the casing The actuator further includes a multi-function spring applying a preloading force to the piezoelectric element. The multi-function spring includes a first segment having a piston configured to translate a motion of the piezoelectric element during operation of the actuator, a second segment having at least one flexural element and a third segment having a first set of threads. The first set of threads is engaged with a second set of threads of the actuator and maintains the second segment in a tension state which corresponds with the preloading force.