Planar Multi-Ion Sensor Without Internal Solution
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Solution Overview
Problem
Conventional multi-ion sensors for measuring sodium and potassium ion concentrations require a constant reference potential, making it difficult to create a thinner sensor with high measurement accuracy, as they need an internal solution for the reference electrode.
Innovation Solution
The multi-ion sensor design allows the potential of the common electrode to vary without affecting the measurement result of the sodium to potassium ion concentration ratio, eliminating the need for an internal solution and enabling sensor thinning, using sensitivity coefficients to accurately measure the concentration ratio based on potential differences between sodium and potassium ion electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a constant reference potential is used for the reference electrode, then measurement accuracy is maintained, but the sensor thickness cannot be reduced due to the requirement for internal solution
Solution Approach 1:
The invention extracts and eliminates the internal solution component from the reference electrode system. By using a common electrode without internal solution and accepting variable potential, the design removes the thickness constraint while maintaining the ability to measure ion concentration ratios through differential measurement between sodium and potassium ion electrodes
Solution Approach 2:
The invention changes the parameter of reference potential from constant to variable. This parameter change allows the elimination of internal solution and reduction of sensor thickness, while the measurement accuracy is preserved through the differential measurement approach that relies on potential differences rather than absolute potential values
2Reliability
If internal solution is provided for the reference electrode, then a constant reference potential is achieved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The invention extracts and removes the internal solution from the reference electrode structure, simplifying the device architecture. This eliminates the complex assembly requirements for sealing and positioning internal solution, making the sensor easier to manufacture while maintaining functional reliability through the alternative common electrode approach
Solution Approach 2:
The common electrode serves multiple functions: it provides a reference point for both sodium and potassium ion measurements, eliminates the need for separate reference electrodes with internal solution, and enables the thin-film structure. This multi-functionality reduces device complexity and manufacturing steps
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
This approach results in a planar type multi-ion sensor that can be easily thinned while maintaining high measurement accuracy for sodium and potassium ion concentrations, even when the common electrode's potential is not constant, and allows for accurate concentration calculations using Ag/AgCl as the common electrode.
Implementation Method 1
a concentration ratio between a concentration of sodium ions and a concentration of potassium ions is obtained from a potential difference between the sodium ion electrode and the potassium ion electrode, using respective sensitivity coefficients of the sodium ion electrode and the potassium ion electrode
Data Source
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AI summary
In order to provide a planar type multi-ion sensor which is easily thinned and has high measurement accuracy, a multi-ion sensor 1 adapted to measure a concentration ratio of sodium ions to potassium ions in a sample solution, includes: a sodium ion electrode 41 selectively reacting to the sodium ions; a potassium ion electrode 42 selectively reacting to the potassium ions; and a common electrode 28 in contrast with the sodium ion electrode 41 and the potassium ion electrode 42, wherein the sodium ion electrode 41, potassium ion electrode 42 and common electrode 28 are provided on the same support body, the common electrode 28 does not include internal solution, and the concentration ratio of the sodium ions to the potassium ions is measured based on a variable A that is obtained by the following Equation (1), A=ENaQ×αNa-EKQ×αK