Micropump

Abstract

A micropump for pumping a fluid, the pump comprising: a tube formed from a piezoelectric material and having inner and outer surfaces; a plurality of electrodes electrifiable to generate vibrations in the tube; and at least one voltage source that applies voltages to the electrodes to generate a displacement traveling wave that propagates along the tube and causes fluid in the tube to flow through the tube.

1 . A micropump for pumping a fluid, the pump comprising:
 a tube formed from a piezoelectric material and having inner and outer surfaces;   a plurality of electrodes comprising first and second linear arrays of outer electrodes respectively located on different portions of the outer surface, the plurality of electrodes being electrifiable to generate vibrations in the tube; and   at least one voltage source that electrifies the electrodes to generate a displacement traveling wave that propagates along the tube and causes fluid in the tube to flow through the tube.   
     
     
         2 - 7 . (canceled) 
     
     
         8 . A micropump according to  claim 1  wherein the tube has a length less than or equal to about 30 mm. 
     
     
         9 . A micropump according to  claim 8  wherein the tube has a length less than or equal to about 15 mm. 
     
     
         10 . (canceled) 
     
     
         11 . A micropump according to  claim 1  wherein the tube has a wall thickness that is less than or equal to about 0.2 mm. 
     
     
         12 . A micropump according to  claim 11  wherein the wall thickness is about equal to 0.1 mm. 
     
     
         13 . A micropump according to  claim 1  wherein the plurality of electrodes comprises an inner electrode covering substantially all the inner surface of the tube. 
     
     
         14 . (canceled) 
     
     
         15 . A micropump according to  claim 1  wherein the first and second linear arrays are substantially mirror images of each other. 
     
     
         16 . A micropump according to  claim 15  wherein each of the first and second linear arrays comprises at least three outer electrodes. 
     
     
         17 . A micropump according to  claim 16  wherein a first electrode of the at least three electrodes in each linear array extends along the tube for a distance equal to about 0.19L, where L is equal to a length of the tube from a region at a first end of the tube at which the tube exhibits a node when the electrodes are electrified to generate the traveling wave to a region of a second end of the tube at which the tube exhibits an antinode when the electrodes are electrified to generate the traveling wave. 
     
     
         18 . A micropump according to  claim 17  wherein a second electrode of the at least three electrodes in each linear array extends along the tube from about where the first electrode ends at about 0.19L to about 0.85L. 
     
     
         19 . A micropump according to  claim 18  wherein the third electrode of the at least three electrodes in each linear array extends along the tube from about where the second electrode ends at about 0.85L to about the region of the second end of the tube. 
     
     
         20 . A micropump according to  claim 19  wherein the voltage source electrifies the first, second, and third electrodes of the first and second linear arrays with harmonic voltages having a same frequency. 
     
     
         21 . A micropump according to  claim 20  wherein a phase difference between the harmonic voltage applied to the first electrode in each array and the second electrode in each array is equal to about 192°. 
     
     
         22 . A micropump according to  claim 21  wherein a phase difference between the harmonic voltage applied to the first electrode in each array and the third electrode in each array is equal to about 100°. 
     
     
         23 . A micropump according to  claim 20  wherein the harmonic voltages applied to homologous electrodes in the first and second arrays are 180° out of phase. 
     
     
         24 . A micropump for pumping a fluid, the micropump comprising:
 a housing having a lumen through which fluid pumped by the micropump flows and first and second flow ports through which fluid pumped by the micropump enters or exits the lumen;   at least one beam comprising at least one layer of piezoelectric material and having a first fixed end fixed to the housing and a second free end free to exhibit vibratory motion located in the lumen; and   a plurality of electrodes electrifiable to generate a displacement traveling wave in each of the at least one beam that propagates along the beam and causes fluid that enters the lumen to flow through and exit the lumen.   
     
     
         25 . A micropump according to  claim 24  wherein the at least one beam comprises one beam. 
     
     
         26 . A micropump according to  claim 24  wherein the at least one beam comprises two beams. 
     
     
         27 . A micropump according to  claim 26  wherein the beams are parallel to each other. 
     
     
         28 . A micropump according to  claim 27  wherein the beams are mirror images of each other. 
     
     
         29 - 30 . (canceled)