Ejector mechanism, ejector device, and methods of use

An ejector device for delivering a fluid to a target, the device comprising:

• 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 separate generator plate, and a piezoelectric actuator coupled to the ejector plate;
• the ejector plate having a first side and a second side opposite the first side, the second side of the ejector plate being coupled to the generator plate;
• the generator plate having a first fluid intake side coupled to the second side of the ejector plate and in fluid communication with reservoir, and a second fluid exit side, the generator plate further including a plurality of openings formed through its thickness, the plurality of openings having an average opening diameter at the second fluid exit side of from about 20 μm to about 100 μm, which average opening diameter at the second fluid exit side is smaller than the average opening diameter at the first fluid intake side;
• and
• the piezoelectric actuator being coupled to one of the first side or the second side of the ejector plate, and being operable to oscillate the ejector plate, and thereby the generator plate, at a frequency and generate a directed stream of droplets;
• wherein one or more of said plurality of openings are shaped so as to comprise a fluid entrance orifice, an entrance cavity, a microchannel, and a fluid exit orifice, the microchannel having a length in the range of from about 70 μm to about 150 μm.