Curie-Temperature Heating Blade for Sensorless Aerosol Control

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Solution Overview

Problem

Existing aerosol generating devices face challenges in temperature control without additional sensors and complexity due to inductive heating elements being integrated into consumables, leading to increased manufacturing costs and potential damage or cleaning issues with heating blades.

Innovation Solution

An aerosol generating device with a removably attachable heating element comprising a bi-material heating blade, where a first material with a Curie temperature below 500°C controls temperature without direct contact, using eddy currents and hysteresis losses for contactless heating, and a second material for efficient heating, eliminating the need for separate temperature sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a separate temperature sensor is added to control heating temperature, then temperature control accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvetemperature control accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The heating element itself serves as the temperature sensing element through its material's Curie temperature characteristics. The ferrite material undergoes a magnetic property change at its Curie temperature, which automatically signals the controller to adjust heating power, eliminating the need for separate temperature sensors and reducing device complexity while maintaining temperature control accuracy.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention utilizes the Curie temperature parameter of ferrite material to achieve temperature control. By selecting ferrite with a specific Curie temperature matching the desired heating temperature, the system automatically regulates temperature through the magnetic property transition of the material, providing accurate temperature control without additional sensing components.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If inductive heating element is integrated into consumable, then manufacturing flexibility is improved, but manufacturing cost increases

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The heating system is divided into two parts: a reusable inductive heating coil in the device body and a disposable consumable containing ferrite heating element. This segmentation allows the complex inductive heating mechanism to be manufactured once in the durable device, while the simpler ferrite element can be easily integrated into consumables, reducing both manufacturing complexity and cost for the consumable portion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The ferrite heating element in the consumable is designed as a low-cost, disposable component. Since ferrite is an inexpensive ceramic material and the element has a simple structure, it can be manufactured cheaply and disposed of with the consumable, eliminating the need for expensive, complex inductive heating integration in each disposable unit.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If heating blade is made durable for multiple uses, then reliability is improved, but ease of repair worsens due to cleaning requirements

Engineering Contradiction:
Improveheating element reliabilityVSAvoidcleaning maintenance
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The ferrite heating element is designed as a disposable component that is replaced rather than cleaned and maintained. This eliminates all cleaning and maintenance requirements while ensuring reliable heating performance for each use, as each new element is guaranteed to be free from contamination or degradation.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 solution reduces device complexity, cost, and maintenance by allowing easy replacement of heating elements, ensuring accurate temperature control and preventing overheating of the aerosol generating substrate.

Implementation Method 1

an inductor configured to generate eddy currents and/or hysteresis losses in the heating element

Methodology Applied
Scientific EffectEddy currents: Eddy Currents

Implementation Method 2

an inductor configured to generate eddy currents and/or hysteresis losses in the heating element

Methodology Applied
Scientific EffectHysteresis losses: Magnetic Hysteresis

Implementation Method 3

The first material has a Curie temperature of less than 500°C

Methodology Applied
Scientific EffectCurie temperature: Curie Point (ferromagnetic)

Data Source

PatentEP3629782B1Heating component in aerosol generating devices
Publication Date: 2025.08.13 PHILIP MORRIS PRODUCTS SA
  • EP3629782B1 patent drawingFigure 1A~2B
  • EP3629782B1 patent drawingFigure 3~5
  • EP3629782B1 patent drawingFigure 6~7B

AI summary

An electronic aerosol-generating device includes a housing extending between first and second ends along a longitudinal axis. The second end of the housing defines a cavity for receiving a consumable containing an aerosol generating substrate. The device further includes a heating component comprising a heating element extending along the longitudinal axis within the cavity and configured to penetrate into the aerosol generating substrate when the consumable is inserted into the cavity. The heating element comprises a material having a Curie temperature of less than 500°C. The device also includes an inductor comprising an inductor coil positioned to transfer magnetic energy to the heating element. The inductor is configured to induce eddy currents and/or hysteresis losses in the heating element. The device further includes a power supply operably connected to the inductor and control electronics operably connected to the power supply and configured to control heating of the heating element.