Reference electrode

Abstract

A reference electrode is disclosed. The reference electrode is developed by spreading an aqueous KCl gelling agar solid gel/poly(vinyl chloride)carboxylated (PVC—COOH) double layer on a screen-printing Ag/AgCl electrode body. Such polymer double layer can maintain ion concentration and keep stable chemical capacitance potential during measurement. The reference electrode of the present invention provides fast response time and high stability for major ions detection measurements in a wide range.

1 . A reference electrode, comprising:
 a insulating substrate;   a conductive layer, placed on said insulating substrate;   an electrode layer, placed on said conductive layer;   a solid electrolytic layer, solidified from an electrolyte by an agar gel and formed onto said electrode layer;   a polymer protective film, placed on said solid electrolytic layer, wherein said polymer protective film comprises at least one or any combination of the following: PVC—COOH, PC (Polycarbonate), Polyester, Polyether, Poly Amide, Polyurethane resin adhesive, Polyimide, PVC (Polyvinyl chloride polymer), PET (Polyrthylene Terephthalate);   an anti-oxidation layer, placed on said conductive layer; and   a insulating layer, placed on said anti-oxidation layer.   
   
   
       2 . A reference electrode of  claim 1 , wherein the ratio of Ag to AgCl in said electrode layer is 1:2. 
   
   
       3 . A reference electrode of  claim 1 , wherein said electrolyte could be a saturated solution of KCl. 
   
   
       4 . A reference electrode of  claim 1 , wherein a mixture of said agar gel and said electrolyte at high temperature is cooled to form said solid electrolytic layer on said electrode layer. 
   
   
       5 . A reference electrode of  claim 1 , wherein said conductive layer and said electrode layer are formed by screen printing method. 
   
   
       6 . A reference electrode of  claim 1 , wherein, by screen printing method, said anti-oxidation layer is formed on the region of said conductive layer which is not covered by said electrode layer. 
   
   
       7 . A reference electrode of  claim 1 , wherein, by screen printing method, said insulating layer is formed on said anti-oxidation layer and said conductive layer to wrap flanks of said electrode layer and said solid electrolytic layer. 
   
   
       8 . A reference electrode of  claim 1 , wherein said insulating layer comprises UV curing gel. 
   
   
       9 . A reference electrode of  claim 1 , wherein said conductive layer comprises Ag paste or ITO (Indium Tin Oxide) conductive film. 
   
   
       10 . A reference electrode, comprising:
 a insulating substrate;   a conductive layer, formed on said insulating substrate;   an electrode layer, formed on said conductive layer;   a solid electrolytic layer, formed on said electrode layer, wherein a mixture of an agar gel and an electrolyte at high temperature is cooled to form said solid electrolytic layer on said electrode layer;   a polymer protective film, smeared over said solid electrolytic layer for protecting said solid electrolytic layer;   an anti-oxidation layer, formed on said conductive layer for preventing the oxidation at said conductive layer; and   a insulating layer, formed on said anti-oxidation layer.   
   
   
       11 . A reference electrode of  claim 10 , wherein the ratio of Ag to AgCl in said electrode layer is 1:2. 
   
   
       12 . A reference electrode of  claim 10 , wherein said polymer protective film comprises at least one or any combination of the following: PVC—COOH, PC (Polycarbonate), Polyester, Polyether, Poly Amide, Polyurethane resin adhesive, Polyimide, PVC (Polyvinyl chloride polymer), PET (Polyrthylene Terephthalate). 
   
   
       13 . A reference electrode of  claim 10 , wherein said insulating layer comprises UV curing gel, and said conductive layer comprises Ag paste or ITO (Indium Tin Oxide) conductive film. 
   
   
       14 . A reference electrode of  claim 10 , wherein said conductive layer, said electrode layer, said anti-oxidation layer, and insulating layer are formed by screen printing method. 
   
   
       15 . A reference electrode fabrication method, comprising the following steps of:
 providing a substrate;   forming a conductive layer on said substrate;   forming an electrode layer on said conductive layer;   forming a solid electrolytic layer on said electrode layer, wherein the forming method of said solid electrolytic layer comprises the following steps of:
 forming a mixture by mixing an agar gel powder and an electrolyte; 
 stirring and mixing said mixture at high temperature; and 
 cooling said mixture at low temperature to solidify said mixture onto said electrode layer; 
   forming an anti-oxidation layer on said conductive layer for preventing the oxidation at said conductive layer;   forming a insulating layer on said anti-oxidation layer;   forming a polymer protective film on said solid electrolytic layer for protecting said solid electrolytic layer.   
   
   
       16 . A reference electrode fabrication method of  claim 15 , wherein said high temperature is in a range between about 100° C. and about 150° C., and said low temperature is in a range between about 0° C. and about 40° C. 
   
   
       17 . A reference electrode fabrication method of  claim 15 , wherein the ratio of Ag and AgCl in said electrode layer is 1:2. 
   
   
       18 . A reference electrode fabrication method of  claim 17 , wherein Ag and AgCl in said electrode layer are baked at a temperature range of about 40° C. to 120° C. 
   
   
       19 . A reference electrode fabrication method of  claim 15 , wherein said electrolyte could be a saturated solution of KCl, and the weight ratio of said agar gel powder and said saturated potassium chloride solution is 4%:96%. 
   
   
       20 . A reference electrode fabrication method of  claim 15 , wherein said conductive layer, said electrode layer, said anti-oxidation layer, and insulating layer are formed by screen printing method.