Electrospray apparatus with an integrated electrode

Abstract

The invention provides related apparatus and methods of making an integrated electrospray tip by depositing ionic and/or electronic conductor materials onto a planar substrate. The invention also features methods of forming an electrospray apparatus comprising coupling a first planar substrate to the surface of a second planar substrate, wherein a surface on at least one of the substrates includes one or more microfluidic channels and/or reservoirs which are at least partially or totally enclosed therebetween. The conductive regions of the apparatus do not intersect the microfluidic channels within other portions of the apparatus provided preferably. The invention further provides related apparatus and methods for manufacturing and using microfluidic devices with integrated electrodes for electrospray ionization. The electrospray apparatus in some embodiments may include an electronic conductor electrode or an ionic conductor electrode formed from a microfluidic channel containing a conductive material selected from a variety of solutions and gels.

1 . A method of making an electrospray apparatus comprising:
 providing a first planar substrate featuring a conductive region; and thereafter   coupling said first planar substrate to a second planar substrate to form a microfluidic channel that is at least partially enclosed therebetween and not intersecting with the conductive region, and wherein at least one of said first and second planar substrates tapers to form an electrospray tip.   
   
   
       2 - 4 . (canceled) 
   
   
       5 . A method of making an electrospray apparatus comprising:
 providing a first planar substrate featuring a conductive region; and thereafter   coupling said first planar substrate to a second planar substrate, said second planar substrate coupled to a third planar substrate, wherein a microfluidic channel is formed between the first planar substrate and the second planar substrate that is at least partially enclosed therebetween and does not intersect the conductive region, and wherein at least one of said second and third planar substrates tapers to form an electrospray tip.   
   
   
       6 - 8 . (canceled) 
   
   
       9 . The method as recited in  claim 1 , wherein said conductive region is made by depositing a conductive material onto a surface of said first planar substrate. 
   
   
       10 . The method as recited in  claim 1 , wherein said conductive region is made by adding a conductive component to a surface portion or all of said first planar substrate. 
   
   
       11 - 53 . (canceled) 
   
   
       54 . The method as recited in  claim 9 , wherein said depositing is carried out by evaporation through a shadow mask. 
   
   
       55 . The method as recited in  claim 54 , further comprising aligning said shadow mask over said first planar substrate. 
   
   
       56 . The method as recited in  claim 54 , wherein said evaporation is at least one evaporation selected from electron beam evaporation and thermal evaporation. 
   
   
       57 . The method as recited in  claim 9 , wherein said depositing is carried out by screen-printing. 
   
   
       58 . The method as recited in  claim 57 , wherein said screen-printing uses at least one device selected from an emulsion screen, a laser-cut stencil, a mesh-mount stencil, and a pump-print stencil. 
   
   
       59 . The method as recited in  claim 9 , wherein said depositing is carried out by sputtering. 
   
   
       60 . The method as recited in  claim 59 , wherein said sputtering is magnetron sputtering. 
   
   
       61 . The method as recited in  claim 9 , wherein said depositing is carried out by dusting. 
   
   
       62 . The method as recited in  claim 61 , wherein said dusting uses at least one approach selected from fairy dusting, silicone glue, and polyimide glue 
   
   
       63 . The method as recited in  claim 1 , wherein said tapering is formed by cutting said substrate that tapers to form an electrospray tip. 
   
   
       64 . The method as recited in  claim 63 , wherein said cutting is die cutting. 
   
   
       65 . The method as recited in  claim 63 , wherein said cutting uses at least one device selected from an iris scissors, a YAG laser, a carbon dioxide laser, a scalpel blade, and an Exacto knife. 
   
   
       66 . The method as recited in  claim 1 , wherein said tapering is formed by folding said substrate. 
   
   
       67 - 79 . (canceled) 
   
   
       80 . The method as recited in  claim 1 , wherein said coupling is carried out by laminating said first and second planar substrates. 
   
   
       81 . The method as recited in  claim 80 , wherein said laminating uses a hot press or two heated rollers. 
   
   
       82 . The method as recited in  claim 80 , wherein said laminating uses at least one approach selected from thermal bonding, a heat-activated adhesive, a pressure-sensitive adhesive, ultrasonic welding, and solvent bonding. 
   
   
       83 . The method as recited in  claim 1 , further comprising rinsing said planar substrate with deionized water and/or a solvent. 
   
   
       84 . The method as recited in  claim 1 , further comprising subjecting said planar substrate to oxygen plasma pretreatment. 
   
   
       85 . The method as recited in  claim 1 , further comprising aligning said first planar substrate over said second planar substrate. 
   
   
       86 . The method as recited in  claim 85 , wherein said aligning uses a layer of a solvent. 
   
   
       87 . The method as recited in  claim 9 , wherein said coupling attaches said first planar substrate to said second planar substrate so that at least a portion of said conductive material lies between said first and second planar substrates. 
   
   
       88 . The method as recited in  claim 9 , wherein said coupling attaches said first planar substrate to said second planar substrate so that said conductive material does not lie between said first and second planar substrates. 
   
   
       89 - 204 . (canceled) 
   
   
       205 . The method of  claim 1 , wherein the conductive region includes an electrode formed from an ionic conductor. 
   
   
       206 . The method of  claim 5 , wherein the conductive region includes an electrode formed from an ionic conductor.