Glazing-Integrated Capacitive Humidity Sensor for Condensation Prediction

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Solution Overview

Problem

Existing vehicle glazing systems with capacitive humidity sensors either require two separate sensors for detection and prediction, increasing manufacturing costs and complicating signal processing, or lack predictive capabilities, leading to inefficient energy consumption due to manual HVAC adjustments.

Innovation Solution

A capacitive humidity sensor with a hygroscopic coating covering part of the electrodes, allowing a single sensor to both detect condensation and predict its formation, using a single signal to optimize HVAC control without increasing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a humidity sensor is integrated into the glazing to enable humidity-dependent control, then functionality and adaptability are improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvehumidity-dependent control functionalityVSAvoidsensor integration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The humidity sensor is merged directly into the glazing structure itself, combining the sensor function with the glazing element. This integration allows the glazing to inherently sense humidity without requiring separate external sensor components, thereby improving adaptability while managing complexity through functional consolidation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The glazing element is designed to serve multiple functions: it acts as both the building envelope component and the humidity sensing element. This multi-functionality approach allows the same structure to provide both structural/weathering functions and environmental sensing, improving versatility without proportionally increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If a humidity sensor is integrated into the glazing, then measurement capability is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvehumidity measurement capabilityVSAvoidsensor integration precision
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The sensor system is segmented into distinct functional layers or components within the glazing structure, allowing each segment to be manufactured and tested independently before final assembly. This segmentation enables precise control of sensor placement and orientation, ensuring measurement precision while managing manufacturing complexity through modular production.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If the glazing surface is made hydrophobic to reduce soiling, then ease of operation is improved, but reliability of humidity sensing deteriorates due to restricted water molecule access

Engineering Contradiction:
Improvesoiling resistanceVSAvoidhumidity sensing accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

Different surface properties are applied to different regions or aspects of the glazing: the outer surface maintains hydrophobic characteristics for soiling resistance, while the inner surface or sensor interface region maintains hydrophilic properties to ensure proper water molecule access for humidity sensing. This local differentiation allows simultaneous optimization of both ease of operation and sensing reliability.

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 effectively predicts condensation before it occurs, enabling automated HVAC adjustments to save energy and reduce manual intervention, while maintaining cost-effectiveness and simplicity in signal processing.

Implementation Method 1

capacitive humidity sensor

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

sensor for detecting a relative humidity

Methodology Applied
Scientific EffectHumidity sensing: Hygrometer

Data Source

PatentEP4302082B1Assembly comprising a window pane with at least one capacitive humidity sensor and electronic processing means
Publication Date: 2026.04.15 SAINT GOBAIN SEKURIT FRANCE
  • EP4302082B1 patent drawingFigure 1~2
  • EP4302082B1 patent drawingFigure 3~5
  • EP4302082B1 patent drawingFigure 6

AI summary

Glazing (1) comprising at least one capacitive humidity sensor (2) with a humidity detection function, comprising two spaced-apart electrodes, characterised in that the capacitive humidity sensor (2) with a detection function also has a humidity prediction function.