METHODS OF MAKING SILVER/SILVER CHLORIDE ELECTRODES BY VAPOR DEPOSITION TECHNIQUES
A method for forming an Ag/AgCl coated electrode includes providing a polymeric electrode substrate made of Acrylonitrile Butadiene Styrene (ABS). A layer of silver (Ag) is deposited on the polymeric electrode substrate using physical vapor deposition (PVD) to form an Ag coated electrode. The layer of Ag is deposited to a first thickness by sputtering an Ag target onto the polymeric electrode substrate. The Ag coated electrode is then converted to a layer of silver/silver chloride (Ag/AgCl) by dipping it into a conversion solution. The resulting Ag/AgCl coated surface electrode provides improved performance and stability for various applications.
1 . A method for forming an Ag/AgCl coated electrode, comprising:
providing a polymeric electrode substrate, the polymeric electrode substrate comprising Acrylonitrile Butadiene Styrene (ABS), wherein the polymeric electrode substrate is configured as a neuromonitoring electrode;
depositing a layer of silver (Ag) on the polymeric electrode substrate by physical vapor deposition (PVD) to form an Ag coated electrode, the layer of Ag being deposited to a first thickness; and
converting the layer of Ag of the Ag coated electrode to a layer of silver/silver chloride (Ag/AgCl) to form a Ag/AgCl surface coated electrode, the converting comprising exposing the Ag coated electrode to a first conversion solution and a second conversion solution.
2 . The method of claim 1 , the polymeric electrode substrate comprising 20 % glass-filled ABS.
3 . The method of claim 1 , further comprising injection molding the polymeric electrode substrate.
4 . The method of claim 1 , the depositing comprising sputtering an Ag target material onto the polymeric electrode substrate.
5 . The method of claim 1 , wherein the exposing comprises spraying the Ag coated electrode.
6 . The method of claim 1 , wherein the exposing comprises dipping the Ag coated electrode.
7 . The method of claim 1 , wherein the first conversion solution comprises sodium hypochlorite (NaOCl) and sodium chloride (NaCl).
8 . The method of claim 1 , wherein the first conversion solution comprises 0 . 2 to 5 % v/v sodium hypochlorite (NaOCl) and up to 10 g/L sodium chloride (NaCl).
9 . The method of claim 1 , wherein the second conversion solution comprises hydrochloric acid (HCL) and sodium selenite (Na 2 SeO 3 ).
10 . The method of claim 1 , wherein the second conversion solution comprises 0 . 25 to 1 M hydrochloric acid (HCL) and 1 to 5 g/L sodium selenite (Na 2 SeO 3 ).
11 . The method of claim 1 , further comprising exposing the Ag coated electrode to the first conversion solution for about 60 to 300 seconds.
12 . The method of claim 1 , further comprising exposing the Ag coated electrode to the second conversion solution for about 600 seconds.
13 . The method of claim 1 , the conversion solution being heated to from about 40 °C to about 50 °C or the conversion solution not being heated.
14 . The method of claim 1 , further comprising a rinsing step, the rinsing comprising exposing the Ag coated electrode to an ammonium hydroxide (NH 4 OH) solution.
15 . The method of claim 14 , wherein the rinsing is carried out for a period of up to about 5 minutes.
16 . The method of claim 1 , further comprising one or more washing steps comprising exposing the electrode to a washing solution.
17 . The method of claim 16 , wherein the washing solution comprises at least one of isopropyl alcohol and/or NaCl.
18 . The method of claim 16 , wherein the one or more washing steps are carried out for about 60 seconds.
19 . The method of claim 1 , the converting further comprising a stabilizing step, comprising placing the Ag/AgCl coated surface electrode in a stabilizing solution.
20 . The method of claim 19 , the stabilizing solution comprising one or more of water, NaCl, and glycerin, and the Ag/AgCl coated surface electrode is placed in the stabilization solution for a stabilization time period.