Electrochemical sensors and methods for making electrochemical sensors using advanced printing technology

Abstract

A sensor can be manufactured by printing a working electrode onto a substrate using aerosol jet printing. Sensing chemistry (e.g., enzyme-based ink that including detection chemistry) also can be printed onto the working electrode using aerosol jet printing. A reference electrode also can be printed on the substrate at a position spaced along the substrate from the working electrode. In certain examples, the substrate can be positioned within a lumen of a skin piercing member of a sensor module.

1 . (canceled) 
     
     
         2 . A sensor comprising:
 a skin piercing member defining a lumen extending along a length of the skin piercing member from a skin piercing end to a base end;   a dielectric spacer disposed within the lumen, the spacer being elongate along the length of the skin piercing member, the spacer extending across a cross-dimension of the lumen to separate the lumen into first and second chambers, the spacer defining a first surface facing outwardly towards a first of the chambers and an opposite second surface facing outwardly towards the second chamber;   a working electrode disposed on the first surface of the dielectric spacer so that the working electrode is accessible from the first chamber, the working electrode being elongate along the length of the skin piercing member;   sensing chemistry disposed at the working electrode; and   a reference electrode disposed on the first surface of the dielectric spacer so that the reference electrode is accessible from the first chamber, the reference electrode being elongate along the length of the skin piercing member.   
     
     
         3 . The sensor of  claim 2 , wherein the working and reference electrodes are printed on the first surface. 
     
     
         4 . The sensor of  claim 3 , wherein the working and reference electrodes are printed on the first surface using aerosol jet printing. 
     
     
         5 . The sensor of  claim 3 , wherein the sensing chemistry is printed on the working electrode using aerosol jet printing. 
     
     
         6 . The sensor of  claim 3 , wherein the sensing chemistry is printed at the reference electrode. 
     
     
         7 . The sensor of  claim 3 , wherein the sensing chemistry is printed at the counter electrode. 
     
     
         8 . The sensor of  claim 2 , wherein the working electrode and the reference electrode are spaced from each other along the cross-dimension of the lumen. 
     
     
         9 . The sensor of  claim 2 , wherein the second surface is devoid of electrodes. 
     
     
         10 . The sensor of  claim 2 , further comprising a counter electrode disposed on the first surface of the dielectric spacer. 
     
     
         11 . The sensor of  claim 10 , wherein the second surface is devoid of electrodes. 
     
     
         12 . The sensor of  claim 2 , further comprising a diffusive membrane coating the sensing chemistry. 
     
     
         13 . The sensor of  claim 2 , wherein the spacer extends along the cross-dimension of the lumen between first and second rounded ends. 
     
     
         14 . The sensor of  claim 2 , wherein working electrode is printed as a pattern defining cells in which the sensing chemistry is printed. 
     
     
         15 . The sensor of  claim 14 , wherein the cells form a honeycomb pattern. 
     
     
         16 . The sensor of  claim 2 , wherein the sensing chemistry is configured to detect glucose. 
     
     
         17 . The sensor of  claim 2 , wherein the skin piercing member is a needle in a range of 28-31 gauge. 
     
     
         18 . A method of manufacturing a glucose sensor, the method comprising:
 printing a plurality of conductive electrodes on a common surface of an elongate spacer, wherein an oppositely facing surface is devoid of conductive electrodes, wherein the conductive electrodes are printed along a length of the elongate spacer;   printing sensing chemistry over the printed conductive electrodes; and   inserting the elongate spacer within a lumen of a skin piercing member so that the elongate spacer separates the lumen into first and second chambers, the first chamber forming a blood sample analysis zone in which the conductive electrodes are disposed.   
     
     
         19 . The method of  claim 18 , wherein printing the plurality of conductive electrodes includes aerosol jet printing the plurality of conductive electrodes. 
     
     
         20 . The method of  claim 18 , wherein printing the sensing chemistry includes aerosol jet printing the sensing chemistry. 
     
     
         21 . The method of  claim 18 , wherein the common surface is disposed between rounded lateral ends of the elongate spacer that contact inner surfaces of the skin piercing member when the elongate spacer is inserted into the lumen.