Continuous analyte sensors and methods of making same

Abstract

Described here are embodiments of processes and systems for the continuous manufacturing of implantable continuous analyte sensors. In some embodiments, a method is provided for sequentially advancing an elongated conductive body through a plurality of stations, each configured to treat the elongated conductive body. In some of these embodiments, one or more of the stations is configured to coat the elongated conductive body using a meniscus coating process, whereby a solution formed of a polymer and a solvent is prepared, the solution is continuously circulated to provide a meniscus on a top portion of a vessel holding the solution, and the elongated conductive body is advanced through the meniscus. The method may also comprise the step of removing excess coating material from the elongated conductive body by advancing the elongated conductive body through a die orifice.

1 - 8 . (canceled) 
     
     
         9 . An implantable electrochemical sensor comprising:
 a working electrode comprising an electroactive surface, wherein the working electrode is configured to be implanted in a host, wherein the working electrode is configured to measure a signal indicative of an analyte concentration; and   a reference electrode comprising silver particles and silver chloride particles.   
     
     
         10 . The sensor of  claim 9 , wherein the silver particles of the reference electrode have an average particle size with a maximum particle dimension that is less than about 100 microns. 
     
     
         11 . The sensor of  claim 9 , wherein the silver particles of the reference electrode have an average particle size with a maximum particle dimension that is less than about 50 microns. 
     
     
         12 . The sensor of  claim 9 , wherein the silver particles of the reference electrode have an average particle size with a maximum particle dimension that is less than about 30 microns. 
     
     
         13 . The sensor of  claim 9 , wherein the silver particles of the reference electrode have an average particle size with a maximum particle dimension that is less than about 10 microns. 
     
     
         14 . The sensor of  claim 9 , wherein the silver chloride particles of the reference electrode have an average particle size with a maximum particle dimension that is less than about 100 microns. 
     
     
         15 . The sensor of  claim 9 , wherein the silver chloride particles of the reference electrode have an average particle size with a maximum particle dimension that is less than about 80 microns. 
     
     
         16 . The sensor of  claim 9 , wherein the silver chloride particles of the reference electrode have an average particle size with a maximum particle dimension that is less than about 60 microns. 
     
     
         17 . The sensor of  claim 9 , wherein the silver chloride particles of the reference electrode have an average particle size with a maximum particle dimension that is less than about 20 microns. 
     
     
         18 . A method for manufacturing an implantable continuous analyte sensor system, the method comprising:
 providing a silver/silver chloride paste, wherein the paste comprises a ratio of silver chloride particle:silver particle from about 0.01:1 to about 2:1 by weight;   applying the silver/silver chloride paste onto a portion of a workpiece, whereby the applied silver/silver chloride forms a reference electrode.   
     
     
         19 . The method of  claim 18 , wherein the ratio of silver chloride particle:silver particle is from about 0.1:1 to about 1:1 by weight. 
     
     
         20 . The method of  claim 19 , wherein the paste comprises silver chloride particles and silver particles mixed with a carrier. 
     
     
         21 . The method of  claim 20 , wherein the silver chloride particles and silver particles form about 10% to about 65% by weight of the paste. 
     
     
         22 . The method of  claim 21 , wherein the silver chloride particles and silver particles form about 20% to about 50% by weight of the paste. 
     
     
         23 . The method of  claim 22 , wherein the silver chloride particles and silver particles form about 23% to about 37% by weight of the paste. 
     
     
         24 . The method of  claim 18 , wherein the paste has a viscosity from about 1 to about 500 centipoise. 
     
     
         25 . The method of  claim 24 , wherein the paste has a viscosity from about 10 to about 300 centipoise. 
     
     
         26 . The method of  claim 25 , wherein the paste has a viscosity from about 50 to about 150 centipoise. 
     
     
         27 . The method of  claim 18 , further comprising:
 providing a solution comprising polyurethane.   
     
     
         28 . The method of  claim 27 , further comprising:
 applying the polyurethane-containing solution to the first electrode.