Micro-droplet 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 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.