Graphene Thermal Imaging for Emissivity-Independent Temperature Sensing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing infrared (IR) detectors struggle to provide accurate temperature measurements in complex structures or high-temperature settings due to uncertainties in emissivity, oxidation, reflection, or discoloration, and require cooling, which limits their application in difficult-to-access environments.

Innovation Solution

A thermal imaging system using stacked graphene arrays with bandpass filters that receive infrared energy at multiple wavelengths, allowing for accurate temperature determination without knowing the emissivity, and operates without cooling due to low background noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional IR detectors are used to measure temperature in high-temperature settings, then temperature measurement capability is provided, but measurement accuracy deteriorates due to unknown emissivity

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidemissivity knowledge requirement
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system segments the infrared spectrum into multiple wavelength bands using stacked graphene arrays with different bandpass filters. Each graphene array detects a specific wavelength range, and by combining measurements from multiple segments, the system can determine temperature without requiring prior knowledge of emissivity, thus resolving the contradiction between measurement accuracy and adaptability to unknown emissivity conditions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes the detection parameter from single-wavelength to multi-wavelength infrared detection. By measuring infrared radiation at multiple wavelengths simultaneously using stacked graphene arrays, the system can calculate temperature based on spectral ratios that eliminate emissivity dependence, thereby maintaining measurement accuracy while adapting to unknown emissivity conditions

Inventive Principle:
Principle #35Parameter changes

2Reliability

If cooling devices are used to cool IR detectors, then detector performance is improved, but device size and complexity increase

Engineering Contradiction:
Improvedetector performanceVSAvoidcooling device size
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention replaces the mechanical cooling system (thermoelectric coolers or liquid nitrogen systems) with a materials-based solution using graphene detectors that inherently operate at ambient temperature. This substitution eliminates the need for complex cooling devices while maintaining detector reliability, as graphene's unique properties allow it to detect infrared radiation without active cooling

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The graphene-based detector system is self-sufficient and does not require external cooling infrastructure. The material itself provides the necessary thermal management properties, allowing the detector to function reliably in high-temperature environments without additional cooling components, thus reducing device complexity while maintaining performance

Inventive Principle:
Principle #25Self-service

3Reliability

If cooling devices are used with IR detectors, then background radiation impact is minimized, but ease of operation in difficult-to-access areas deteriorates

Engineering Contradiction:
Improvebackground radiation rejectionVSAvoiddeployability in difficult-to-access areas
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The invention replaces the mechanical cooling infrastructure with ambient-temperature graphene detectors that inherently reject background radiation through their material properties. This eliminates the need for bulky cooling systems and utilities, making the device portable and suitable for deployment in difficult-to-access areas while maintaining reliable background radiation rejection

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention extracts and removes the cooling device component from the detector system entirely. By using graphene materials that operate at ambient temperature, the system eliminates the cooling subsystem while retaining the essential function of background radiation rejection, thereby improving ease of operation in remote or difficult-to-access locations

Inventive Principle:
Principle #2Taking out (Extraction)

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

Enables accurate temperature measurement in high-temperature environments with improved resolution and flexibility, overcoming emissivity uncertainties and eliminating the need for cooling.

Implementation Method 1

Energy having a first wavelength is received at the first array of graphene sensors. Energy having a second wavelength is received at the second array of graphene sensors

Methodology Applied
Scientific EffectInfrared absorption: Absorption (EM radiation)

Implementation Method 2

A first material is placed onto the first array of graphene sensors to form a first bandpass filter. A number of bandpass filters are separating the stacked graphene arrays

Methodology Applied
Scientific EffectBandpass filtering: Filter (optical)

Data Source

PatentEP3407041B1Thermal imagining system
Publication Date: 2026.05.20 THE BOEING CO
  • EP3407041B1 patent drawingFigure 1
  • EP3407041B1 patent drawingFigure 2
  • EP3407041B1 patent drawingFigure 3

AI summary

A thermal imaging system comprises a substrate, stacked graphene arrays on the substrate, and a number of bandpass filters separating the stacked graphene arrays. (Fig. 6)