Ejector mechanism, ejector device, and methods of use

An ejector device and method of delivering safe, suitable, and repeatable dosages to a subject for topical, oral, nasal, or pulmonary use is disclosed. The ejector device includes a housing, a reservoir disposed within the housing for receiving a volume of fluid, and an ejector mechanism in fluid communication with the reservoir and configured to eject a stream of droplets, the ejector mechanism comprising an ejector plate coupled to a generator plate and a piezoelectric actuator; the piezoelectric actuator being operable to oscillate the ejector plate, and thereby the generator plate, at a frequency and generate a directed stream of droplets.