Electroosmosis Pump and Liquid Feeding Device

Abstract

In an electroosmosis pump, a bubble separation member is provided at an exit side chamber so as to be separated from an exit side electrode, a gas vent member is provided at that side section of a pump container which is near the exit side electrode, and a gas vent member is provided at that side section of the pump container which is near an entrance side electrode. A self-filling mechanism is placed in an entrance side chamber, and the self-filling mechanism is composed of a liquid drawing member in contact with an electroosmosis material via the entrance side electrode, and of an air vent path formed between a member surrounding a side section of the liquid drawing member and the inner wall of the pump container.

1 . An electroosmotic pump including a first electrode and a second electrode disposed upstream and downstream, respectively, from an electroosmotic member disposed in a fluid passage, wherein, when a voltage is applied to said first electrode and said second electrode, a drive liquid is caused to flow in said fluid passage through said electroosmotic member, characterized in that
 a downstream liquid passing member, for preventing gas produced in the vicinity of said second electrode when said voltage is applied from passing downstream, and for passing the drive liquid therethrough, is disposed downstream from said second electrode on a downstream side of said fluid passage.   
   
   
       2 . An electroosmotic pump according to  claim 1 , characterized in that
 a downstream gas vent, for discharging said gas out of said fluid passage to outside, is disposed between said electroosmotic member and said downstream liquid passing member.   
   
   
       3 . An electroosmotic pump according to  claim 1 , characterized in that
 an upstream liquid passing member, for preventing foreign matter from flowing into said electroosmotic member and passing said drive liquid therethrough when said voltage is applied, is disposed upstream from said electroosmotic member on an upstream side of said fluid passage.   
   
   
       4 . An electroosmotic pump according to  claim 3 , characterized in that
 an upstream gas vent, for discharging gas produced in the vicinity of said first electrode, to outside, when said voltage is applied, is disposed between said electroosmotic member and said upstream liquid passing member.   
   
   
       5 . An electroosmotic pump according to  claim 1 , characterized in that
 an upstream liquid self-priming mechanisms, for self-priming said drive liquid, is disposed on an upstream side of said fluid passage in contact with one of said electroosmotic member and said first electrode.   
   
   
       6 . An electroosmotic pump according to  claim 1 , characterized in that
 a downstream liquid self-priming mechanism, for self-priming said drive liquid, is disposed on a downstream side of said fluid passage in contact with one of said electroosmotic member and said second electrode.   
   
   
       7 . An electroosmotic pump including a first electrode and a second electrode disposed upstream and downstream, respectively, from an electroosmotic member disposed in a fluid passage, wherein, when a voltage is applied to said first electrode and said second electrode, a drive liquid is caused to flow in said fluid passage through said electroosmotic member, characterized in that
 an upstream liquid self-priming mechanism, for self-priming said drive liquid, is disposed on an upstream side of said fluid passage in contact with one of said electroosmotic member and said first electrode.   
   
   
       8 . An electroosmotic pump according to  claim 7 , characterized in that
 an upstream liquid passing member, for preventing foreign matter from flowing into said electroosmotic member and passing said drive liquid therethrough when said voltage is applied, is disposed upstream from said electroosmotic member on an upstream side of said fluid passage.   
   
   
       9 . An electroosmotic pump according to  claim 8 , characterized in that
 an upstream gas vent, for discharging gas produced in the vicinity of said first electrode to outside when said voltage is applied, is disposed between said electroosmotic member and said upstream liquid passing member.   
   
   
       10 . An electroosmotic pump according to  claim 7 , characterized in that
 a downstream liquid self-priming mechanism, for self-priming said drive liquid, is disposed on a downstream side of said fluid passage in contact with one of said electroosmotic member and said second electrodes.   
   
   
       11 . An electroosmotic pump according to  claim 7 , characterized in that
 a downstream liquid passing member, for preventing said gas from passing downstream and passing said drive liquid therethrough, is disposed downstream from said second electrode on a downstream side of said fluid passage.   
   
   
       12 . An electroosmotic pump according to  claim 11 , characterized in that
 a downstream gas vent, for discharging gas produced in the vicinity of said second electrode to outside when said voltage is applied, is disposed between said electroosmotic member and said downstream liquid passing member.   
   
   
       13 . An electroosmotic pump according to  claim 12 , characterized in that
 said liquid passing member is made of a hydrophilic material;   a gas pressure required for gas to pass through said liquid passing member is 1 [kPa] or higher; and   said liquid passing member has a thickness of 3 [mm] or less along a direction of said fluid passage.   
   
   
       14 . An electroosmotic pump according to  claim 12 , characterized in that
 said gas vent is made of a hydrophobic material disposed on a side wall of said fluid passage;   a pressure under which said drive liquid passes over said gas vent is larger than a maximum pressure of said drive liquid when said electroosmotic pump is in operation; and   said gas vent has a thickness of 3 [mm] or less along the direction in which said gas passes.   
   
   
       15 . An electroosmotic pump according to  claim 7 , characterized in that
 said liquid self-priming mechanism comprises a self-priming member disposed in the vicinity of said electroosmotic member along said fluid passage, and an air vent disposed alongside said self-priming member and having an impregnation pressure that is different from the impregnation pressure of said self-priming member; and   said self-priming member is self-primed with said drive liquid and supplies said drive liquid to said electroosmotic member, and said air vent discharges air remaining upstream from said electroosmotic member, to outside, based on an impregnation pressure difference between said self-priming member and said air vent.   
   
   
       16 . An electroosmotic pump according to  claim 15 , characterized in that
 said self-priming member is made of a hydrophilic material and said air vent is made of a hydrophobic material.   
   
   
       17 . An electroosmotic pump according to  claim 11 , characterized in that
 said electroosmotic member or said first electrode and said upstream liquid passing member are spaced from each other by an interval of 3 [mm] or less along the direction of said fluid passage, and/or   said electroosmotic member or said second electrode and said downstream liquid passing member are spaced from each other by an interval of 3 [mm] or less along the direction of said fluid passage.   
   
   
       18 . An electroosmotic pump according to  claim 7 , characterized in that
 a drive liquid absorbing member made of a hydrophilic material, which closely contacts with said upstream liquid self-priming mechanism and said electroosmotic member or said first electrode, is disposed between said upstream liquid self-priming mechanism and said electroosmotic member or said first electrode, and/or   a drive liquid absorbing member made of a hydrophilic material, which closely contacts with said downstream liquid self-priming mechanism and said electroosmotic member or said second electrode, is disposed between said downstream liquid self-priming mechanism and said electroosmotic member or said second electrode.   
   
   
       19 . An electroosmotic pump according to  claim 7 , characterized in that
 said fluid passage is defined in a pump casing accommodating therein said electroosmotic member, said first electrode, and said second electrode; and   said fluid passage has an upstream inlet and a downstream outlet defined in one surface of said pump casing.   
   
   
       20 . A liquid feeding device comprising:
 an electroosmotic pump according to  claim 7 ; and   a liquid container filled with a liquid,   wherein said liquid in said liquid container is supplied to outside by said electroosmotic pump.