Electrochemical cell with increased current density

Abstract

A nanopore cell is disclosed. The nanopore cell includes an electrolyte well having a bottom base, a surrounding sidewall, and a hydrophobic surface above the surrounding sidewall. The nanopore cell further includes a first layer of electrode material disposed on the bottom base of the electrolyte well. The nanopore cell further includes a second layer of electrode material disposed on the surrounding sidewall of the electrolyte well and electrically connected to the first layer of electrode material. The first layer of electrode material and the second layer of electrode material are configured to jointly provide capacitive coupling when an electrolyte is placed in the electrolyte well.

What is claimed is: 
     
         1 . A method of constructing a nanopore cell, comprising:
 constructing an electrolyte well having a bottom base, a surrounding sidewall, and a hydrophobic surface above the surrounding sidewall;   disposing a first layer of electrode material on the bottom base of the electrolyte well; and   disposing a second layer of electrode material on the surrounding sidewall of the electrolyte well, and wherein the second layer of electrode material is electrically connected to the first layer of electrode material; and   wherein the first layer of electrode material and the second layer of electrode material are configured to jointly provide capacitive coupling when an electrolyte is placed in the electrolyte well.   
     
     
         2 . The method of  claim 1 , wherein the first layer of electrode material and the second layer of electrode material form a single working electrode of the nanopore cell. 
     
     
         3 . The method of  claim 2 , and wherein the first layer of electrode material forms a substantially planar portion of the working electrode, and wherein the second layer of electrode material forms a surrounding wall of the working electrode, and wherein the surrounding wall of the working electrode extends perpendicular to or at an angle from the substantially planar portion and along the periphery of the substantially planar portion of the working electrode. 
     
     
         4 . The method of  claim 3 , and wherein an aspect ratio of the working electrode comprises a ratio between a height of the surrounding wall of the working electrode and a width of the substantially planar portion of the working electrode, and wherein the aspect ratio is selected in part based on a desired ratio of a capacitance associated with a membrane and a capacitance associated with the working electrode, and wherein the membrane is formed atop the electrolyte well and spans across an opening of the well. 
     
     
         5 . The method of  claim 3 , and wherein a width of the substantially planar portion of the working electrode is between 1 to 100 microns. 
     
     
         6 . The method of  claim 3 , and wherein a height of the surrounding wall of the working electrode is between 100 nm to 20 microns. 
     
     
         7 . The method of  claim 2 , wherein the working electrode comprises a spongy and porous TiN working electrode that is deposited by a deposition technique with conditions tuned to deposit sparsely-spaced TiN columnar structures or columns of TiN crystals. 
     
     
         8 . The method of  claim 1 , wherein the hydrophobic surface above the surrounding sidewall provides a surface for facilitating a membrane to form atop the electrolyte well, and wherein the membrane spans across an opening of the electrolyte well. 
     
     
         9 . The method of  claim 8 , wherein the hydrophobic surface extends downward partially into the electrolyte well and covers part of the surrounding sidewall of the electrolyte well to further facilitate a membrane to form atop the electrolyte well and to span across the opening of the electrolyte well.