Nitrous Oxide Sensor With Indium Electrode And Segmented Chambers

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Solution Overview

Problem

Existing nitrous oxide sensors are slow, bulky, and prone to interference from oxygen, which affects their accuracy and reliability in environmental monitoring and wastewater treatment applications.

Innovation Solution

An electrochemical sensor design featuring a primary chamber with a permeable membrane for nitrous oxide and a secondary chamber with an indium working electrode, using an aprotic solvent and an oxygen scavenger to minimize oxygen interference, allowing for efficient and sensitive nitrous oxide detection with a low zero-current and high signal-to-noise ratio.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional electrochemical sensors are used for nitrous oxide detection, then oxygen interference is eliminated by using alkaline ascorbate solution, but the sensor becomes bulky and slow with 90% response times of 40-50 seconds

Engineering Contradiction:
Improveoxygen interference eliminationVSAvoidresponse time
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The sensor is divided into two separate chambers: a primary chamber that eliminates oxygen interference using alkaline ascorbate solution, and a secondary chamber that contains the indium working electrode for fast nitrous oxide detection. This segmentation allows each chamber to be optimized independently, resolving the contradiction between oxygen elimination and fast response.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The oxygen elimination function is extracted into a separate primary chamber that is physically distinct from the detection chamber. The primary chamber contains the alkaline ascorbate solution that removes oxygen before it reaches the secondary chamber, allowing the secondary chamber to focus solely on fast nitrous oxide detection without being burdened by oxygen elimination requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If traditional sensors with larger tip diameters (50-80 micrometer) are used, then oxygen elimination is more effective, but the sensor becomes less compact and more bulky

Engineering Contradiction:
Improveoxygen elimination effectivenessVSAvoidsensor size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The sensor is divided into two separate chambers: a primary chamber that eliminates oxygen interference using alkaline ascorbate solution, and a secondary chamber that contains the indium working electrode for fast nitrous oxide detection. This segmentation allows each chamber to be optimized independently, resolving the contradiction between oxygen elimination and fast response.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The secondary chamber containing the indium working electrode is positioned within or adjacent to the primary chamber that performs oxygen elimination. This nested arrangement allows the smaller secondary detection chamber to be protected and serviced by the larger primary chamber, achieving compact overall sensor design while maintaining effective oxygen elimination.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Measurement precision

If indium working electrode with aprotic solvent is used, then detection sensitivity is improved with low zero-current, but the device complexity increases due to dual chamber structure

Engineering Contradiction:
Improvedetection sensitivityVSAvoidsensor structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sensor is divided into two separate chambers: a primary chamber that eliminates oxygen interference using alkaline ascorbate solution, and a secondary chamber that contains the indium working electrode for fast nitrous oxide detection. This segmentation allows each chamber to be optimized independently, resolving the contradiction between oxygen elimination and fast response.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each chamber is given different local properties: the primary chamber contains alkaline ascorbate solution optimized for oxygen elimination, while the secondary chamber contains indium working electrode in aprotic solvent optimized for sensitive nitrous oxide detection. This local differentiation allows each part to excel at its specific function despite increased overall structural complexity.

Inventive Principle:
Principle #3Local quality

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 sensor provides a more efficient, sensitive, durable, and compact solution for nitrous oxide detection, offering improved reliability and stability, with a low detection limit and extended lifespan, suitable for environmental monitoring and wastewater treatment.

Implementation Method 1

the secondary opening membrane (124) is permeable to nitrous oxide and is arranged so as to separate a primary volume (116) from a secondary volume (126)

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 2

the working electrode (104) comprises indium (In)

Methodology Applied
Scientific EffectElectrochemical reduction: Reduction

Implementation Method 3

the primary chamber (110) comprises means for hindering oxygen in passing into the secondary volume (126)

Methodology Applied
Scientific EffectOxygen scavenging: Absorption (physical)

Data Source

PatentEP2939012B1An electrochemical sensor for sensing nitrous oxide
Publication Date: 2018.09.19 UNISENSE ENVIRONMENT
  • EP2939012B1 patent drawingFigure 1
  • EP2939012B1 patent drawingFigure 2~3
  • EP2939012B1 patent drawingFigure 4

AI summary

There is presented an electrochemical sensor (100) for sensing nitrous oxide (N2O) in an associated volume (106), the sensor comprising a primary chamber (110), a secondary chamber (120) being placed adjacent the primary chamber (110), the secondary chamber (120) comprising electrodes for performing electrochemical measurements and furthermore an electrolyte comprising an aprotic solvent. A first membrane (114) and a secondary membrane (124) are permeable to nitrous oxide and may be arranged so as to separate the associated volume (106) from a primary volume (116) within the primary chamber (110), and the primary volume (116) from a secondary volume (126) within the secondary chamber (120), where the primary chamber (110) comprises means for hindering oxygen in passing into the secondary volume (126), and wherein the working electrode (104) comprises indium (In).