Electrochemical Oxygen Sensor Isolating Device Gradient

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Solution Overview

Problem

Existing electrochemical oxygen sensors face challenges in maintaining a sufficient oxygen gradient between the measuring and counter electrodes, leading to slow response times and increased size due to the need for large electrode distances, which complicates portable designs and increases inner resistance.

Innovation Solution

An electrochemical oxygen sensor design with a housing containing a first aperture for oxygen intake and a second aperture for oxygen escape, where the counter electrode is adjacent to the second aperture, and an isolating device is interposed between the measuring and counter electrodes, allowing for close proximity of the electrodes while maintaining an oxygen gradient through the isolating device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large distance is maintained between the measuring electrode and the counter electrode, then a sufficient oxygen gradient is ensured, but the sensor size increases and response time is delayed

Engineering Contradiction:
Improveoxygen gradient maintenanceVSAvoidresponse time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent introduces an isolating device as an intermediary element positioned between the measuring electrode and the counter electrode. This isolating device prevents direct oxygen diffusion from the counter electrode to the measuring electrode, thereby maintaining the oxygen gradient without requiring a large physical distance between the electrodes. The isolating device acts as a mediator that allows ionic current passage while blocking oxygen molecules, resolving the contradiction between gradient maintenance and response time.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a large distance is maintained between the measuring electrode and the counter electrode, then a sufficient oxygen gradient is ensured, but the inner resistance of the sensor increases

Engineering Contradiction:
Improveoxygen gradient maintenanceVSAvoidinner resistance
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The isolating device serves as an intermediary that enables close positioning of the measuring and counter electrodes while preventing oxygen back-diffusion. By placing the electrodes close together, the ionic path length in the electrolyte is reduced, which decreases the inner resistance of the sensor. The isolating device ensures that despite the reduced distance, the oxygen gradient is maintained by blocking direct oxygen diffusion pathways.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If the counter electrode is positioned far from the second aperture, then oxygen can escape, but the sensor size increases

Engineering Contradiction:
Improveoxygen escapeVSAvoidsensor housing volume
Core Design Contradiction:
Object-generated harmful factorsVSVolume of stationary object

Solution Approach 1:

The patent merges the functions of oxygen escape and electrode positioning by placing the counter electrode adjacent to the second aperture. This configuration allows oxygen generated at the counter electrode to escape directly through the nearest aperture without requiring additional space. The combining of these functions reduces the overall sensor housing volume while ensuring effective oxygen removal from the system.

Inventive Principle:
Principle #5Merging (Combining)

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 design achieves a response time of under 1 minute, with the consuming reaction being at least 10 times faster than the response time, ensuring immediate oxygen consumption at the measuring electrode and preventing back diffusion, thus enhancing sensor performance and reducing size.

Implementation Method 1

at the measuring electrode, O2 is reduced to 2O2-

Methodology Applied
Scientific EffectElectrochemical reduction: Redox Reactions

Implementation Method 2

at least one isolating device (11) is interposed between the measuring electrode (6) and the counter electrode (5)

Methodology Applied
Scientific EffectDiffusion barrier: Diffusion Barrier

Data Source

PatentEP2002251B1Oxygen sensor
Publication Date: 2015.11.04 LIFE SAFETY GERMANY
  • EP2002251B1 patent drawingFigure 1
  • EP2002251B1 patent drawingFigure 2

AI summary

An electrochemical oxygen sensor (1), comprising a housing (12) enclosing a chamber filled with electrolyte, at least one measuring electrode (6) for detecting oxygen, at least one counter electrode (5), and at least one reference electrode (9), wherein the housing (12) comprises at least one first aperture (2) for allowing oxygen to contact the measuring electrode and at least one second aperture (3) for allowing oxygen to escape from the chamber, wherein the counter electrode (5) is disposed adjacent to the second aperture (3).