Analyte sensor and fabrication methods

Abstract

Methods for fabricating analyte sensor components using IC- or MEMs-based fabrication techniques and sensors prepared therefrom. Fabrication of the analyte sensor component comprises providing an inorganic substrate having deposited thereon a release layer, a first flexible dielectric layer and a second flexible dielectric layer insulating there between electrodes, contact pads and traces connecting the electrodes and the contact pads of a plurality of sensors. Openings are provided in one of the dielectric layers over one or more of the electrodes to receive an analyte sensing membrane for the detection of an analyte of interest and for electrical connection with external electronics. The plurality of fabricated sensor components are lifted off the inorganic substrate.

That which is claimed: 
     
         1 . A method for fabricating an electrochemical sensor component comprising:
 providing a substrate;   depositing a release layer on the substrate;   depositing a first flexible dielectric layer on the release layer;   defining perimeters in the first flexible dielectric layer of a plurality of individual continuously connected electrodes, traces and contact pads;   depositing conductive material in at least a portion of the perimeters formed in the first flexible dielectric layer;   depositing a second flexible dielectric layer over the plurality of individual continuously connected electrodes, traces and contact pads and the first flexible dielectric layer;   forming openings in the second flexible dielectric layer exposing at least a portion of at least one of the individual continuously connected electrodes and contact pads; and   chemically removing the release layer between the first flexible dielectric material and the substrate, whereby the flexible electrochemical sensor component is released from the substrate.   
     
     
         2 . The method of  claim 1 , further comprising depositing an analyte sensing membrane in the opening positioned over the electrode. 
     
     
         3 . The method of  claim 2 , wherein the analyte sensing membrane comprises:
 a hydrophilic polymer layer;   an interference layer;   an enzyme layer; and   a flux-limiting layer.   
     
     
         4 . The method of  claim 2 , wherein the analyte sensing membrane encapsulates the opening over the electrode. 
     
     
         5 . A method for fabricating an electrochemical sensor component comprising:
 providing a substrate;   depositing a release layer on the substrate;   depositing a first flexible dielectric layer on the release layer;   depositing conductive material on the first flexible dielectric material;   depositing a mask layer on the conductive material;   defining perimeters for at least one continuously connected electrode, trace and contact pad in the mask layer;   forming a plurality of individual continuously connected electrodes, traces and contact pads of the conductive material as defined by the perimeters in the mask layer;   depositing a second flexible dielectric layer over the plurality of individual continuously connected electrodes, traces and contact pads and the first flexible dielectric layer;   forming at least one opening in the second flexible dielectric layer exposing at least a portion of at least one of the individual continuously connected electrodes and contact pads; and   chemically removing the release layer between the first flexible dielectric material and the substrate, whereby the flexible electrochemical sensor component is released from the substrate.   
     
     
         6 . The method of  claim 5 , wherein the release layer comprises (i) a solubility in a solvent that does not substantially dissolve the first or second flexible dielectric layers; or (ii) an etch rate (wet or dry) faster than the first flexible dielectric layer. 
     
     
         7 . The method of  claim 5 , wherein the release layer is silicon dioxide, silica glass, or aluminum. 
     
     
         8 . The method of  claim 5 , wherein chemically removing the release layer comprises wet etching or dry etching. 
     
     
         9 . The method of  claim 5 , further comprising depositing a first adhesion layer between at least a portion of the first flexible dielectric material and the conductive material and further comprising depositing a second adhesion layer between the conductive material and at least a portion of the second flexible dielectric material. 
     
     
         10 . The method of  claim 5 , further comprising depositing an analyte sensing membrane in the opening positioned over the electrode. 
     
     
         11 . The method of  claim 10 , wherein the analyte sensing membrane comprises:
 a hydrophilic polymer layer;   an interference layer;   an enzyme layer; and   a flux-limiting layer.   
     
     
         12 . The method of  claim 10 , wherein the analyte sensing membrane encapsulates the opening over the electrode.