Fluid delivery devices and methods are described where the device may comprise a piezoelectric actuator having a piezoelectric chip that is operatively coupled to a drug package under a preloading force. The actuator is configured to generate an acoustic pressure within the drug package to dispense droplets or a continuous stream of an agent from an aperture, e.g., to the corneal surface of the eye. The piezoelectric actuator can be coupled or decoupled from the drug package via a coupling mechanism which enables the quick release and consistent securement of the drug package to the actuator and housing.
