Sieve electrooosmotic flow pump

Abstract

The present invention provides a pump for generating an Electroosmotic Flow (EOF) in a solution in a canal, guide, pipe or equivalent. Electroosmotic flow is generated by application of an electric field through a solution in a canal defined by insulating walls. The phenomenon depends on ionisation of sites on the surface so that for electroneutrality there is an excess mobile charge in the solution. The electric field acts on the excess charge in the solution causing the fluid to flow. The quantity and distribution of excess charge in the solution depends on the solution and the surface materials and is related to a parameter, the zeta (z) potential characterising material/solution combinations.

1 . An electroosmotic flow pump for generating a flow in an ionic solution from an inlet to an outlet in a canal, the electroosmotic flow pump comprising a housing with the canal for holding the ionic solution, a membrane separating the canal in a first part in contact with the inlet and a second part in contact with the outlet, the membrane comprising a plurality of perforations each of which perforations comprises an inner surface with a zeta potential ξ10 mV in an 130-160 mM aqueous salt solution with pH value in the interval 7-7.5, one or more first electrodes in electrical contact with ionic solution held in the first part of the canal and one or more second electrodes in electrical contact with ionic solution held in the second part of the canal, means for impressing an electric potential difference between the first and second electrodes.  
     
     
         2 . An electroosmotic flow pump according to  claim 1 , wherein a thickness of the membrane is in the interval 0.1-2 μm.  
     
     
         3 . An electroosmotic flow pump according to  claim 1 , wherein the number of performations in the membrane is in the range of 5-500.  
     
     
         4 . An electroosmotic flow pump according to  claim 1 , wherein the inner radii of the perforations are in the interval 0.1-5 μm.  
     
     
         5 . An electroosmotic flow pump according to  claim 1 , wherein an average distance between any perforation and its closest neighbor is in the interval 2-100 μm.