Droplet Ejector With Oscillating Tapered Aperture

Abstract

A fluid injection device for ejecting fluid droplets in response to electrical signals comprises an oscillating surface that has one or more tapered apertures, each aperture having a first and second opening. The first opening of each aperture is larger than the second opening. The first opening is in surface tension contact with the fluid to be ejected. The fluid interaction with the tapered aperture wall creates cycles of fluid compression and decompression inside the aperture, causing fluid to be drawn from the large opening and ejected out the small opening of the aperture. The device includes a fluid supply nozzle that transports fluid to the oscillating surface at the large opening of the apertures. A discharge valve controls the fluid supply. An electronic wave generator induces oscillation in the tapered aperture containing surface. The device is used to great advantage for fluid atomization and fluid spray.

1 - 26 . (canceled)  
     
     
         27 . A droplet ejection device comprising: 
 a curved member having a plurality of tapered apertures extending therethrough;    a support structure that is configured to support the curved member in a manner that permits the curved member to vibrate;    a piezoelectric member that is configured to vibrate the curved member; and    a source of liquid;    wherein upon supplying a liquid to the curved member and vibrating the curved member with the piezoelectric member, liquid droplets are ejected through the tapered apertures.    
     
     
         28 . A device as in  claim 27 , wherein the source of liquid is unpressurized when supplied to the curved member.  
     
     
         29 . A device as in  claim 27 , wherein the tapered apertures are circular in geometry.  
     
     
         30 . A device as in  claim 27 , wherein the curved member has a front surface and a rear surface, and wherein the apertures taper from the rear surface to the front surface.  
     
     
         31 . A device as in  claim 30 , wherein the source of liquid is in communication with the rear surface.  
     
     
         32 . A droplet ejection device, comprising: 
 a curved member having a plurality of tapered apertures extending therethrough;    a support structure that is configured to support the curved member in a manner that permits the curved member to vibrate;    a piezoelectric member that is configured to vibrate the curved member;    a region adapted to hold a volume of liquid, with the liquid being in contact with the curved member;    wherein upon vibrating the curved member with the piezoelectric member, liquid droplets are ejected through the tapered apertures.    
     
     
         33 . A device as in  claim 32 , wherein the tapered apertures are circular in geometry.  
     
     
         34 . A device as in  claim 32 , wherein the curved member has a front surface and a rear surface, and wherein the apertures taper from the rear surface to the front surface.  
     
     
         34 . A device as in  claim 32 , wherein the volume of liquid is unpressurized.