Porous Aerosol-Generating Substrate for Lower-Temperature Nicotine Release

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Solution Overview

Problem

Existing aerosol-generating substrates face challenges in providing effective release of aerosol and nicotine at lower temperatures while minimizing undesirable compounds, addressing leakage issues, and ensuring easy integration into existing aerosol-generating articles without significant modifications.

Innovation Solution

An aerosol-generating substrate comprising a porous medium loaded with a heterogeneous aerosol-generating suspension of inert powder in a liquid solvent, which includes aerosol formers and a nicotine source, is developed. The suspension is formed by mixing inert powder with the liquid solvent and deposited onto a porous medium to create a substrate that can be readily incorporated into existing articles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If homogenised tobacco material is heated at high temperatures (around 350°C) to optimise aerosol generation, then aerosol and nicotine release is improved, but undesirable compounds are generated and higher energy consumption is required

Engineering Contradiction:
Improveaerosol and nicotine releaseVSAvoidundesirable compounds
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent changes the physical state parameter of the nicotine source from solid particulate tobacco to liquid nicotine composition, enabling effective aerosol generation at lower temperatures (200-300°C) while minimizing the formation of undesirable compounds associated with high-temperature combustion of solid tobacco material

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transition of the thermoreversible gel composition, which becomes fluid when heated to melting temperature and sets into gel again at gelation temperature, enabling controlled release of liquid nicotine at lower temperatures without generating harmful high-temperature byproducts

Inventive Principle:
Principle #36Phase transitions

2Quantity of substance

If liquid nicotine compositions are used in containers, then aerosol generation is enabled, but leakage issues occur requiring particular care in manufacture

Engineering Contradiction:
Improvenicotine deliveryVSAvoidleakage prevention
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent employs a thermoreversible gel composition that transitions between gel and fluid states based on temperature, allowing the nicotine-containing composition to be contained in a stable gel form during storage and handling, then becoming fluid only when heated for aerosol generation, thereby eliminating leakage issues

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent creates a composite gel system combining nicotine, gelling agent, and other components that provides both containment stability and controlled release capability, eliminating the need for complex leakage-prevention manufacturing while ensuring reliable nicotine delivery

Inventive Principle:
Principle #40Composite materials

3Reliability

If gel compositions are used to prevent leakage, then reliability is improved, but the gel cannot be retained within the rod substrate and leakage occurs

Engineering Contradiction:
Improveleakage preventionVSAvoidgel retention in substrate
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent incorporates the thermoreversible gel composition into a porous rod substrate structure that provides capillary retention of the gel material, preventing leakage while maintaining the gel's temperature-responsive properties for controlled aerosol generation

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent creates a composite structure combining the gel composition with the porous rod substrate, where the substrate provides mechanical retention and the gel provides controlled release, achieving both stability and reliability

Inventive Principle:
Principle #40Composite materials

4Quantity of substance

If internal heating elements are inserted into the rod to heat homogenised tobacco, then aerosol generation is optimized, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveaerosol generation efficiencyVSAvoidinternal heating element integration
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical internal heating element system with an external heating approach that utilizes the temperature-responsive properties of the thermoreversible gel, simplifying device construction while maintaining efficient aerosol generation through the gel's inherent phase transition mechanism

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

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 substrate optimizes aerosol and nicotine release at lower temperatures, reduces leakage, and maintains sensorial properties, while being efficiently manufacturable and compatible with existing aerosol-generating devices.

Implementation Method 1

volatile compounds are released from the aerosol-generating substrate by heat transfer from the heat source

Methodology Applied
Scientific EffectVaporization: Evaporation

Implementation Method 2

As the released compounds cool, they condense to form an aerosol

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 3

a porous medium loaded with an heterogeneous aerosol-generating suspension

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP4444115B1Aerosol-generating article with novel aerosol-generating substrate
Publication Date: 2025.09.10 PHILIP MORRIS PRODUCTS SA
  • EP4444115B1 patent drawingFigure 1

AI summary

An aerosol-generating article (10) comprises an aerosol-generating substrate comprising : a porous medium loaded with an heterogeneous aerosol-generating suspension of an inert powder in a liquid solvent, the liquid solvent comprising one or more aerosol formers and a [liquid] nicotine source. The aerosol-generating suspension comprises at least 20 percent by weight of the inert powder and at least 30 percent by weight of the one or more aerosol formers.