Aircraft Thermal Sensor Using Phase-Change Material

Solution Overview

Problem

Conventional thermal sensors for aircraft components, particularly those with polymer composite materials, require faster response times and lower temperature activation to effectively detect overheat conditions.

Innovation Solution

A thermal sensor design featuring a support layer with a state-changing material that transitions from non-conductive to conductive at a threshold temperature, using electrodes and a sealant to create a sandwich structure, allowing for faster and more sensitive heat detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional thermal sensors use granular porous ceramic or glass layers with salt mixtures, then they provide reliable overheat detection, but they have slow response time and require higher activation temperatures

Engineering Contradiction:

Improveoverheat detection reliabilityVSAvoidresponse time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent utilizes phase transitions of state-changing materials (melting from solid to liquid) to trigger electrical conductivity changes. This phase transition mechanism enables faster response times compared to conventional salt mixture melting, while maintaining reliable detection through the clear phase change event at specific temperatures.

Inventive Principle:

Principle #36Phase transitions

Solution Approach 2:

The patent changes the physical and chemical parameters of the sensing material by replacing conventional salt mixtures with state-changing materials that have lower melting points and faster phase transition kinetics. This parameter change enables lower activation temperatures and faster response times while maintaining detection reliability.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If conventional thermal sensors use granular porous ceramic or glass layers with salt mixtures, then they provide reliable overheat detection, but they have slow response time and require higher activation temperatures

Engineering Contradiction:

Improveoverheat detection reliabilityVSAvoidactivation temperature

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent utilizes phase transitions of state-changing materials (melting from solid to liquid) to trigger electrical conductivity changes. This phase transition mechanism enables faster response times compared to conventional salt mixture melting, while maintaining reliable detection through the clear phase change event at specific temperatures.

Inventive Principle:

Principle #36Phase transitions

Solution Approach 2:

The patent changes the physical and chemical parameters of the sensing material by replacing conventional salt mixtures with state-changing materials that have lower melting points and faster phase transition kinetics. This parameter change enables lower activation temperatures and faster response times while maintaining detection reliability.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If the sensor structure uses rigid components for stability, then it maintains structural integrity, but it cannot conform to complex shapes

Engineering Contradiction:

Improvestructural integrityVSAvoidconformability to complex shapes

Core Design Contradiction:

Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent employs flexible thin film structures for the sensor components, allowing the sensor to conform to complex curved surfaces and irregular shapes while maintaining structural integrity. The thin film design provides both flexibility for adaptation and sufficient mechanical strength for stability.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent uses composite material structures combining different materials with complementary properties - such as flexible substrates with conductive layers - to achieve both structural integrity and conformability. The composite structure allows the sensor to maintain stability while adapting to complex geometries.

Inventive Principle:

Principle #40Composite materials

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 solution enables faster and more sensitive overheat detection in aircraft components, reducing response time and weight while maintaining reliability, and allowing for conformability to complex shapes without damage.

Implementation Method 1

the state changing material transitions between a non-conductive state to a conductive state at a threshold temperature

Methodology Applied

Scientific EffectPhase change: Phase Change

Implementation Method 2

the phase changing material converts from a solid to a liquid

Methodology Applied

Scientific EffectMelting: Melting

Implementation Method 3

The support layer can be an anodized layer on at least one interior surface of one electrode

Methodology Applied

Scientific EffectAnodizing: Anodising

Data Source

PatentUS10539471B2Thermal sensor

Publication Date: 2020.01.21 KIDDE TECHNOLOGIES INC

AI summary

A thermal sensor for an aircraft includes a first electrode, a second electrode, a support layer disposed between the first electrode and the second electrode, and a state changing material is configured to disposed within the support layer, wherein the state changing material transitions between a non-conductive state to a conductive state at a threshold temperature to electrically connect the first and second electrodes.