Fluid Sensor Humidity Control Using Internal Sorbent Circulation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing sensor systems for detecting chemicals in gases, such as electrochemical and FAIMS sensors, face challenges in humidity control, requiring costly and large hardware for effective operation.

Innovation Solution

A sensor system utilizing a sorbent material within the housing to condition the fluid, either by absorbing or releasing water, with a circulation mechanism that alternates between sensing and regeneration paths to manage humidity levels, allowing for efficient and cost-effective humidity control without external air supplies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If active humidity control hardware is used, then humidity control performance is improved, but device size and cost increase

Engineering Contradiction:
Improvehumidity control performanceVSAvoidhardware size and cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sensor system uses its own internal sorbent material and circulation pump to control humidity, without requiring external active humidity control hardware. The sorbent material passively absorbs excess moisture from the enclosed environment, and the circulation pump periodically moves air through the sorbent, enabling the system to self-regulate humidity levels.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention extracts the humidity control function from external active hardware and implements it internally using passive sorbent materials and a simple circulation mechanism. This removes the need for complex external humidity control systems while maintaining effective humidity management within the sensor housing.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If external air supply is used for humidity control, then humidity management is improved, but device portability is reduced

Engineering Contradiction:
Improvehumidity managementVSAvoiddevice portability
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The invention combines the humidity control function with the sensor housing itself, creating an integrated enclosed environment. The sorbent material and circulation pump are incorporated within the housing, merging multiple functions (sensing, humidity control, and sample handling) into a single portable unit that requires no external air supply.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The enclosed housing with internal sorbent material and circulation pump creates a self-contained system that manages its own humidity levels without requiring connection to external air supplies or environmental controls, enabling true portability while maintaining reliable humidity management.

Inventive Principle:
Principle #25Self-service

3Device complexity

If sorbent material is used for passive humidity control, then device size is reduced, but control precision may worsen

Engineering Contradiction:
Improvedevice sizeVSAvoidhumidity control precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The circulation pump operates periodically to move air through the sorbent material, creating cyclic humidity control action. This periodic circulation ensures that moisture is continuously removed from the enclosed environment and that the sorbent material is regularly reactivated, maintaining precise humidity control despite the passive nature of the sorbent.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system controls humidity by changing the operational parameters of the circulation pump (on/off cycles, flow rate) to match the moisture generation rate of the sensor. By dynamically adjusting the circulation parameters, the system maintains precise humidity control adaptively responding to changing sensor moisture emissions.

Inventive Principle:
Principle #35Parameter changes

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 enables stable and prolonged operation of sensor systems by effectively managing humidity, reducing costs, and allowing for thousands of average measurements over the sensor's lifespan.

Implementation Method 1

The conditioning material may be a sorbent, i.e. any suitable material which adsorbs or absorbs the particular substance, typically water, from the fluid

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

controlling a direction of operation of the circulation means which drives the fluid in a selected fluid path between the sensor and the conditioning chamber

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP3662500B1Fluid sensor system and method for analysing fluid
Publication Date: 2024.06.12 OWLSTONE MEDICAL LTD
  • EP3662500B1 patent drawingFigure 1A~1B
  • EP3662500B1 patent drawingFigure 1C~2A
  • EP3662500B1 patent drawingFigure 2B~2C

AI summary

A sensor system comprising a housing (10) having an inlet aperture (18) through which fluid enters the housing (10) and a conditioning material (32) in the housing (10), the conditioning material (32) being adapted to control levels of a substance within the housing (10). The sensor system comprises a sensor (12) for analysing the fluid in the housing (10). The sensor system comprises circulation means (14) which is configured to alternate circulation of fluid within the housing (10) between a sensing fluid path in which the fluid is analysed by the sensor (12) and a second fluid path in which the fluid flow is conditioned. A method for analysing fluid in a housing (10) using a sensor (12) is also provided.