Electrohydrodynamic Micropump and Its Use

Abstract

An electrohydrodynamic micropump having at least one pumping passage for pumping a liquid, wherein there is at least one electrode device for generating an electrical alternating field and at least one device for producing a temperature gradient in the liquid to be pumped, which is arranged in and/or on the at least one pumping passage.

1 - 38 . (canceled) 
   
   
       39 . An electrohydrodynamic micropump comprising:
 at least one pumping passage for pumping a liquid flowing medium;   at least one electrode device for generating an alternating electric field; and   at least one heating device for generating a temperature gradient in the liquid to be pumped being arranged in and/or at said at least one pumping passage.   
   
   
       40 . The electrohydrodynamic micropump according to  claim 39 , wherein said at least one electrode device and said at least one device for generating the temperature gradient are coupled. 
   
   
       41 . The electrohydrodynamic micropump according to  claim 39 , wherein said at least one pumping passage is at least partly linear. 
   
   
       42 . The electrohydrodynamic micropump according to  claim 39 , wherein said at least one pumping passage includes two or more segments. 
   
   
       43 . The electrohydrodynamic micropump according to  claim 42 , wherein said segments are linear and disposed at an angle between 0° and 180°. 
   
   
       44 . The electrohydrodynamic micropump according to  claim 42 , wherein said electrode device includes at least two electrodes, and said segments and said electrodes are arranged such that the an inflow of the liquid flowing medium is substantially vertical to electric field lines generated by said electrode device. 
   
   
       45 . The electrohydrodynamic micropump according to  claim 44 , wherein the outflow of the liquid flowing medium is substantially parallel to the electric field lines. 
   
   
       46 . The electrohydrodynamic micropump according to  claim 42 , wherein said at least two segments have a transition region including at least one flow guiding member. 
   
   
       47 . The electrohydrodynamic micropump according to  claim 46 , wherein said at least one flow guiding member constricts a flow cross-section for the liquid flowing medium. 
   
   
       48 . The electrohydrodynamic micropump according to  claim 39 , wherein said electrode device includes at least one first electrode and at least one second electrode, said first electrode and second electrode are located opposite each other, and the liquid flowing medium flows between said first and second electrodes. 
   
   
       49 . The electrohydrodynamic micropump according to  claim 39 , wherein said electrode devices includes a first and second electrodes and the electric field is formed between said first and second electrodes in said at least one pumping passage. 
   
   
       50 . The electrohydrodynamic micropump according to  claim 39 , wherein said electrode device comprises at least two electrodes extending flat on at least one of a the bottom, ceiling or side wall of said at least one pumping passage. 
   
   
       51 . The electrohydrodynamic micropump according to  claim 39 , wherein said electrode device includes at least one electrode which is at least partly surrounded by the liquid flowing medium. 
   
   
       52 . The electrohydrodynamic micropump according to  claim 39 , wherein said electrode device includes an electrode which is one of a grating or one wire mesh and is traversed by the liquid flowing medium. 
   
   
       53 . The electrohydrodynamic micropump according to  claim 39 , wherein said electrode device comprises at least two metallic electrodes with a high thermal conductivity. 
   
   
       54 . The electrohydrodynamic micropump according to  claim 39 , wherein said electrode device comprises at least two metallic electrodes with different thermal conductivity. 
   
   
       55 . The electrohydrodynamic micropump according to  claim 39 , wherein said electrode device comprises at least two electrodes with at least one of different dimensions or shapes. 
   
   
       56 . The electrohydrodynamic micropump according to  claim 39 , wherein said electrode device comprises at least first and second electrodes, said first electrode has at least one of a greater surface area, a greater thickness or a greater volume than said second electrode. 
   
   
       57 . The electrohydrodynamic micropump according to  claim 39 , wherein said heating device comprises at least one heating element disposed for generating an additional temperature gradient and arranged in said at least one pumping passage. 
   
   
       58 . The electrohydrodynamic micropump according to  claim 57 , wherein said at least one heating element is arranged in said at least one pumping passage in a flow direction one of before or behind said electrode device. 
   
   
       59 . The electrohydrodynamic micropump according to  claim 57 , wherein said electrode device includes an electrode and said at least one heating element ( 3 ) and said electrode ( 5 ) are at least partly combined in one component. 
   
   
       60 . The electrohydrodynamic micropump according to  claim 57 , wherein said at least one heating element is a conducting microstructure with an electrically insulated surface comprising at least one of heating wires or thermal radiators. 
   
   
       61 . The electrohydrodynamic micropump according to  claim 39 , wherein the alternating electric field has one of a sinusoidal or rectangular time pattern and is generated one of continuously or pulsed. 
   
   
       62 . The electrohydrodynamic micropump according to  claim 39 , wherein the alternating electric field has a frequency which is an electric resonance frequency of the micropump. 
   
   
       63 . The electrohydrodynamic micropump according to  claim 39 , wherein said micropump has an additional inductive resonance system, in which the liquid flowing medium to be pumped is at least part of a dielectric of a capacitive element. 
   
   
       64 . The electrohydrodynamic micropump according to  claim 39 , wherein said at least one pumping passage is arranged on a microsystem comprising one of a μTAS-chip or a Lab-on-Chip system. 
   
   
       65 . The electrohydrodynamic micropump according to  claim 64 , wherein said at least one pumping passage is arranged in a chamber which comprises a microreactor. 
   
   
       66 . The electrohydrodynamic micropump according to  claim 65 , wherein said microreactor includes at least one of a chemical or biological reaction system. 
   
   
       67 . The electrohydrodynamic micropump according to  claim 39 , wherein said at least one pumping passage is coupled to a pumping system comprising at least one pumping chamber and at least one discharge chamber. 
   
   
       68 . The electrohydrodynamic micropump according to  claim 67 , wherein said at least one pumping chamber opens into said at least one pumping passage on at least one discharge opening. 
   
   
       69 . The electrohydrodynamic micropump according to  claim 67 , wherein said at least one pumping passage opens into said discharge chamber on at least one outlet opening. 
   
   
       70 . The electrohydrodynamic micropump according to  claim 67 , wherein said one discharge chamber is one of directly or indirectly connected with at least one further passage. 
   
   
       71 . The electrohydrodynamic micropump according to  claim 70 , wherein said pumping chamber and said discharge chamber are connected by said further passage. 
   
   
       72 . The electrohydrodynamic micropump according to  claim 70 , wherein said pumping chamber, said at least one pumping passage, said discharge chamber and said further passage comprise a pumping system which is closed at least for a time. 
   
   
       73 . The electrohydrodynamic micropump according to  claim 72 , wherein one of said pumping system or said chamber comprise a microreactor, and said microreactor is filled or evacuated by a microdosing system. 
   
   
       74 . A method of pumping liquids, which comprises:
 providing an electrohydrodynamic micropump for pumping liquids according to  claim 39 , and   pumping liquids with the micropump.   
   
   
       75 . A method for pumping a liquid in an electrohydrodynamic micropump, comprising the steps of:
 forming an alternating electric field and a temperature gradient in a liquid being pumped between electrodes in at least one pumping passage; and   controlling a pumping direction by a frequency of the alternating electric field applied and the temperature gradient in the at least one pumping passage.   
   
   
       76 . The method according to  claim 75 , including the further step of:
 forming an additional temperature gradient by using a heating element, and   causing the additional temperature gradient to extend into a region of the alternating electric field between the electrodes or overlap the field wholly or in part.   
   
   
       77 . The electrohydrodynamic micropump according to  claim 43 , wherein said at least two linear segments are disposed at an angle of substantially 90°. 
   
   
       78 . The electrohydrodynamic micropump according to  claim 46 , wherein said at least two segments have a transition region, and at least one non-dielectric flow guiding member device dispose din said transition region. 
   
   
       79 . The electrohydrodynamic micropump according to  claim 47 , wherein said at least one flow guiding member has a wedge-shaped cross-section. 
   
   
       80 . The electrohydrodynamic micropump according to  claim 42 , wherein said one flow guiding member is a non-dielectric material. 
   
   
       81 . The electrohydrodynamic micropump according to  claim 47 , wherein said at least one flow guiding member has a wedge-shaped cross-section.