Fluid dispenser and dispensing methods

Abstract

A fluid dispenser comprises a fluid chamber having two actuators coupled thereto. One of the actuators damps a fluid response of the other. The fluid chamber may comprises a cylindrical capillary, and the actuators may comprise spaced cylindrical piezoelectric elements.

1 - 3 . (Canceled)  
     
     
         4 . An apparatus for dispensing droplets of fluid comprising: 
 a fluid chamber having an opening therein for droplet dispensing;    a first actuator mechanically coupled to said fluid chamber and configured to alter the volume thereof;    a second actuator mechanically coupled to said fluid chamber and configured to alter the volume thereof; and    a driver connected to actuate said first and said second actuators so as to alter the volume of said fluid chamber, whereby a fluid response produced by said first actuator is damped by said second actuator.    
     
     
         5 . The apparatus of  claim 4 , wherein said driver is connected to actuate said first and said second actuators substantially simultaneously.  
     
     
         6 . The apparatus of  claim 4 , wherein said driver is connected to actuate said second actuator prior to actuating said first actuator.  
     
     
         7 . The apparatus of  claim 4 , wherein said first and said second actuators comprise piezoelectric material.  
     
     
         8 - 13 . (Canceled)  
     
     
         14 . A method of droplet deposition comprising: 
 altering the volume of a fluid chamber with a first actuator;    damping a fluid response to said volume alteration with a second actuator.    
     
     
         15 . The method of  claim 14 , wherein said altering comprises compressing said fluid chamber.  
     
     
         16 . The method of  claim 15 , wherein said damping comprises compressing said fluid chamber.  
     
     
         17 . The method of  claim 15 , wherein said compressing is performed substantially simultaneously.  
     
     
         18 . The method of  claim 17 , wherein said compressing is performed sequentially.  
     
     
         19 . The method of  claim 14 , wherein said altering comprises electrically actuating a first piece of piezoelectric material, and wherein said damping comprises electrically actuating a second piece of piezoelectric material.  
     
     
         20 . The method of  claim 19 , wherein said actuating a first piece of piezoelectric material and actuating a second piece of piezoelectric material are performed substantially simultaneously  
     
     
         21 . A droplet dispensing apparatus comprising: 
 a fluid chamber;    a first means for altering the volume of said fluid chamber; and    a second means for altering the volume of said fluid chamber, wherein said second means additionally comprises means for damping a fluid response to said first means.    
     
     
         22 . The droplet dispenser of  claim 21 , wherein said first and said second volume altering means comprise piezoelectric material.  
     
     
         23 . The droplet dispensing apparatus of  claim 22 , additionally comprising a driver circuit connected in parallel to said first and said second piezoelectric means.  
     
     
         24 - 26 . (Canceled)  
     
     
         27 . A droplet dispensing apparatus comprising: a fluid chamber; a first piezoelectric means for altering the volume of said fluid chamber; and a second piezoelectric means for damping a fluid response to said altering.