Micro electro-kinetic pump having a nano porous membrane

Abstract

An electro-kinetic micro pump having a nano porous membrane is introduced. When a voltage is applied to two opposing sides of the nano porous membrane, an electro-osmotic flow can be induced in each nano pore of the membrane. Since the pore diameter of the nano porous membrane is in the range of nano meters, the fluid inside the nano pore would be almost unipolar. As a result, by compared to a traditional micro electro-kinetic pump, the electro-kinetic micro pump having the nano porous membrane can produce a larger flow rate. Moreover, since the required driving voltage for the present micro pump is much smaller than that for the traditional micro pump, energy conversion efficiency of the present pump can be greatly improved.

1 . A micro electro-kinetic pump having a nano porous membrane, comprising: 
 a nano porous membrane for passing there through a fluid, having a plurality of nano pores, a pore diameter of each the nano pore being ranged between 1 nm and 1,000 nm; and    two electrodes mounted to two opposing sides of the nano porous membrane for accepting an across voltage so as to form an electro-osmotic flow inside each the nano pore.    
   
   
       2 . The micro electro-kinetic pump according to  claim 1 , wherein said nano porous membrane is made of a material that makes the fluid presenting an electrical double layer effect.  
   
   
       3 . The micro electro-kinetic pump according to  claim 1 , wherein said electrode is made of a metal grid material.  
   
   
       4 . The micro electro-kinetic pump according to  claim 3 , wherein said metal grid material is selected from the group of silver, gold, platinum and stainless steel.  
   
   
       5 . The micro electro-kinetic pump according to  claim 3 , wherein said metal grid material has a line width ranged from 1 nm to 100 μm.  
   
   
       6 . The micro electro-kinetic pump according to  claim 3 , wherein said metal grid material has a line spacing and a line width, in which the line spacing is equal or on the same order to the line width.  
   
   
       7 . The micro electro-kinetic pump according to  claim 1 , wherein said electrode is coated by a silver layer.  
   
   
       8 . The micro electro-kinetic pump according to  claim 7 , wherein said silver layer has a thickness of 900 nm.  
   
   
       9 . The micro electro-kinetic pump according to  claim 1 , wherein said fluid has a debye length that double of the debye length is greater than or on the same order to a pore diameter of said nano pore so as to make said nano pore being unipolar.