Polymer Coated Reference Electrode for Miniaturization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional silver/silver chloride reference electrodes face challenges in miniaturization and stability due to the loss of key chemical components, particularly in applications like scanning electrochemical microscopy and microfluidics, where maintaining a stable chloride concentration and solid silver chloride is difficult.
Innovation Solution
A coated substrate with a cation exchange polymer, such as Nafion, and a redox active substance present in both oxidized and reduced states is used, forming a solid-state, liquid-free reference electrode that can be miniaturized and is stable over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a silver/silver chloride electrode is used with a zone of aqueous chloride solution and solid silver chloride, then a stable reference potential can be maintained, but the electrode size increases and miniaturization becomes difficult
Solution Approach 1:
The patent extracts the essential function of maintaining a stable reference potential from the conventional Ag/AgCl electrode system by removing the aqueous chloride solution and solid silver chloride components. Instead, it uses a polymer coating containing redox-active species that can maintain a stable potential without requiring bulk chloride solution or solid AgCl reservoirs, thereby enabling miniaturization.
Solution Approach 2:
The patent changes the chemical parameters of the reference electrode system by replacing the chloride-based equilibrium system with a polymer-based redox system. The polymer coating contains redox-active species that establish a stable potential through their oxidation state equilibrium, fundamentally changing how the reference potential is maintained while reducing size requirements.
2Ease of operation
If a silver/silver chloride electrode is exposed to chloride containing solution, then it can function as a reference electrode, but silver chloride is lost from the surface leading to deterioration
Solution Approach 1:
The patent removes the silver chloride component that is prone to loss and deterioration. The polymer coating system functions as a reference electrode without containing silver chloride, thereby eliminating the problem of AgCl loss from the electrode surface while maintaining reference electrode functionality.
Solution Approach 2:
The patent employs a polymer coating that is more stable and less prone to degradation than silver chloride. This polymer-based system replaces the deteriorating AgCl layer with a more robust material that maintains its integrity over time, effectively creating a long-lasting reference electrode surface.
3Reliability
If solid silver chloride is maintained at the electrode surface to sustain equilibrium, then a stable reference potential is achieved, but the electrode becomes complex and difficult to miniaturize
Solution Approach 1:
The patent merges the reference electrode function directly into the electrode surface itself by using a polymer coating that contains the redox-active species. This eliminates the need for separate silver chloride layers and chloride solution reservoirs, simplifying the overall electrode structure while maintaining stable reference potential.
Solution Approach 2:
The patent changes the physical state parameters by transitioning from a system requiring solid AgCl and aqueous solution to a solid-state polymer coating system. This parameter change simplifies the electrode structure by eliminating liquid components and multiple phases, making the electrode easier to manufacture and miniaturize.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The coated substrate provides a stable and reproducible reference electrode with minimal potential drift, suitable for nanoscale applications and long-term use, as it eliminates the loss of key chemical components and maintains a consistent potential.
Implementation Method 1
the polymer is a cation exchange polymer
Implementation Method 2
the redox active substance is present in both an oxidised and reduced state
Data Source
Figure 1(a)~1(b)
Figure 2(a)~2(b)
Figure 3(a)~3(b)
AI summary
The present disclosure provides for a coated, substrate for use as an electrode, the coated substrate comprising a substrate that is at least partially coated with a layer comprising a polymer and a redox active substance, wherein the polymer is a cation exchange polymer, and wherein the redox active substance is present in both an oxidised and reduced state. A method for making the isolated coated substrate, and an electrochemical apparatus using the electrode as a reference electrode, is also discussed herein.