Piezoelectric fluid pump

Abstract

A compact, high capacity pump for pumping fluid. A first one-way valve is between an inlet port and the pump's fluid chamber. A second one-way valve is between the pump's fluid chamber and an outlet port. A diaphragm separates a piezoelectric stack from the fluid chamber. A power source provides power to the piezoelectric stack causing it to expand and contract. The expansion and contraction of the piezoelectric stack causes fluid to be pumped from the inlet port to the fluid chamber through the first one-way valve and causes fluid to be pumped from the fluid chamber to the outlet port through the second one-way valve. In one preferred embodiment, both one-way valves are disc valves. In another preferred embodiment both one-way valves are MEMS valves.

1 . A compact, high capacity pump, comprising:
 A) an inlet port and an outlet port,   B) a fluid chamber,   C) a first one-way valve located flow wise between said inlet port and said fluid chamber,   D) a second one-way valve located flow wise between said fluid chamber and said outlet port,   E) a piezoelectric stack,   F) a diaphragm separating said piezoelectric stack and said fluid chamber, and   G) a power source for providing periodically varying voltage signals to said piezoelectric stack to cause expansion and contraction of said piezoelectric stack to produce fluid flow from said inlet port to said outlet port.   
   
   
       2 . The pump as in  claim 1 , wherein said first one-way valve and said second one-way valve are both passive one-way disc valves. 
   
   
       3 . The pump as in  claim 1 , wherein said first one-way valve and said second one-way valve are both active one-way disc valves. 
   
   
       4 . The pump as in  claim 1 , wherein said first one-way valve and said second one-way valve are both passive microvalve arrays. 
   
   
       5 . The pump as in  claim 1 , wherein said first one-way valve and said second one-way valve are both active microvalve arrays. 
   
   
       6 . The pump as in  claim 3 , further comprising:
 A) a first power source for providing power to said first one-way valve,   B) a second power source for providing power to said second one-way valve,   C) a pressure sensor for sensing the pressure inside said fluid chamber, and   D) a microprocessor electrically connected to said pressure sensor and said first power source and said second power source.   
   
   
       7 . The pump as in  claim 4 , wherein said first one-way valve and said second one-way valve are both passive MEMS valve arrays. 
   
   
       8 . The pump as in  claim 5 , wherein said first one-way valve and said second one-way valve are both active MEMS valve arrays. 
   
   
       9 . The pump as in  claim 8 , further comprising:
 A) a first power source for providing power to said first one-way valve,   B) a second power source for providing power to said second one-way valve,   C) a pressure sensor for sensing the pressure inside said fluid chamber, and   D) a microprocessor electrically connected to said pressure sensor and said first power source and said second power source.   
   
   
       10 . A compact, high capacity pump, comprising:
 A) an inlet port means and an outlet port means,   B) a fluid chamber means,   C) a first one-way valve means located flow wise between said inlet port means and said fluid chamber means,   D) a second one-way valve means located flow wise between said fluid chamber means and said outlet port means,   E) a piezoelectric stack means,   F) a diaphragm means separating said piezoelectric stack means and said fluid chamber means, and   G) a power source means for providing periodically varying voltage signals to said piezoelectric stack means to cause expansion and contraction of said piezoelectric stack means to produce fluid flow from said inlet port means to said outlet port means.   
   
   
       11 . The pump as in  claim 10 , wherein said first one-way valve means and said second one-way valve means are both passive one-way disc valve means. 
   
   
       12 . The pump as in  claim 10 , wherein said first one-way valve means and said second one-way valve means are both active one-way disc valve means. 
   
   
       13 . The pump as in  claim 10 , wherein said first one-way valve means and said second one-way valve means are both passive microvalve array means. 
   
   
       14 . The pump as in  claim 10 , wherein said first one-way valve means and said second one-way valve means are both active microvalve array means. 
   
   
       15 . The pump as in  claim 12 , further comprising:
 A) a first power source means for providing power to said first one-way valve means,   B) a second power source means for providing power to said second one-way valve means,   C) a pressure sensor means for sensing the pressure inside said fluid chamber means, and   D) a microprocessor means electrically connected to said pressure sensor means and said first power source means and said second power source means.   
   
   
       16 . The pump as in  claim 13 , wherein said first one-way valve means and said second one-way valve means are both passive MEMS valve array means. 
   
   
       17 . The pump as in  claim 14 , wherein said first one-way valve means and said second one-way valve means are both active MEMS valve array means. 
   
   
       18 . The pump as in  claim 17 , further comprising:
 A) a first power source means for providing power to said first one-way valve means,   B) a second power source means for providing power to said second one-way valve means,   C) a pressure sensor means for sensing the pressure inside said fluid chamber means, and   D) a microprocessor means electrically connected to said pressure sensor means and said first power source means and said second power source means.   
   
   
       19 . The pump as in  claim 1 , wherein said piezoelectric stack is operated at resonant frequency. 
   
   
       20 . A method for pumping fluid, comprising the steps of:
 A) connecting a compact high capacity pump to a power source, said pump comprising:
 1) an inlet port and an outlet port 
 2) a fluid chamber, 
 3) a first one-way valve located flow wise between said inlet port and said fluid chamber, 
 4) a second one-way valve located flow wise between said fluid chamber and said outlet port, 
 5) a piezoelectric stack, 
 6) a diaphragm separating said piezoelectric stack and said fluid chamber, 
   B) utilizing said power source to provide periodically varying voltage signals to said piezoelectric stack to cause expansion and contraction of said piezoelectric stack to produce fluid flow from said inlet port to said outlet port.