Superhydrophobic Cartridge Coating for Complete Aerosol Liquid Discharge

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Solution Overview

Problem

Residual liquid composition remains inside the cartridge of aerosol generating devices due to high viscosity, leading to difficulty in discharge and frequent cartridge replacement.

Innovation Solution

A cartridge with a coating layer having superhydrophobicity formed along the inner surface, featuring microscale protrusions, and a liquid layer with immiscibility to the liquid composition, enhancing superhydrophobicity based on distance from the heater.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the liquid composition is accommodated in the container unit, then the liquid composition can be stored and heated to generate aerosol, but the residual liquid composition remains inside the cartridge due to high viscosity and is difficult to be discharged

Engineering Contradiction:
Improveliquid composition discharge completenessVSAvoidliquid composition dischargeability
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The invention changes the surface energy parameter of the container unit's inner surface by applying a superhydrophobic coating. This coating creates extreme water repellency (contact angle >150°), which fundamentally alters the interaction between the liquid composition and the surface, enabling complete discharge even for high viscosity liquids without changing the liquid's properties.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces mechanical discharge methods (which would require physical agitation or pressure) with a surface chemistry-based solution. The superhydrophobic coating creates a low-adhesion surface that passively facilitates liquid release through minimal mechanical action, substituting complex mechanical discharge systems with a surface property-based mechanism.

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

2Quantity of substance

If the liquid composition having high viscosity is stored in the cartridge, then the liquid composition can be accommodated, but it is difficult to be discharged through a physical method

Engineering Contradiction:
Improveliquid composition retentionVSAvoidliquid composition dischargeability
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The superhydrophobic coating changes the surface energy parameter from hydrophilic to superhydrophobic, creating a surface with extremely low adhesion to liquids. This parameter change allows high viscosity liquids to be retained during storage while enabling complete discharge when needed, as the liquid does not adhere to the surface.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite structure consisting of the container unit material combined with a superhydrophobic coating layer. This composite surface combines the structural integrity of the container material with the low-adhesion properties of the superhydrophobic coating, achieving both retention and dischargeability.

Inventive Principle:
Principle #40Composite materials

3Quantity of substance

If the inner surface of the container unit is in contact with the liquid composition, then the liquid composition can be accommodated, but the inner surface is impregnated with the liquid composition

Engineering Contradiction:
Improveliquid composition accommodationVSAvoidcontainer unit reusability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The superhydrophobic coating changes the surface energy parameter to create extreme liquid repellency. This parameter change prevents liquid impregnation while still allowing liquid accommodation, as the liquid forms discrete droplets on the surface rather than penetrating or adhering to it.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The superhydrophobic coating acts as an intermediary layer between the container unit's inner surface and the liquid composition. This intermediate layer prevents direct contact and impregnation between the liquid and the container surface, while still allowing the liquid to be accommodated and discharged.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If the cartridge is used repeatedly, then the convenience of smoking is improved, but frequent cartridge replacement is required due to residual liquid composition

Engineering Contradiction:
Improvesmoking convenienceVSAvoidcartridge usage duration
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The superhydrophobic coating changes the surface energy parameter to enable complete liquid discharge. This parameter change extends cartridge usage duration by ensuring no residual liquid remains after each use, allowing the cartridge to be reused more times before replacement is necessary.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The superhydrophobic coating provides a self-cleaning effect where the liquid composition automatically releases from the surface without requiring manual intervention. This self-service mechanism prevents residue buildup that would otherwise require cleaning or replacement, extending cartridge life and maintaining smoking convenience.

Inventive Principle:
Principle #25Self-service

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

Facilitates easy discharge of the liquid composition, preventing the inner surface from being impregnated and reducing the need for frequent cartridge replacements.

Implementation Method 1

a coating layer having superhydrophobicity formed along an inner surface of the container unit

Methodology Applied
Scientific EffectSuperhydrophobicity: Hydrophobe

Data Source

PatentEP4691288A1Cartridge and aerosol-generating device
Publication Date: 2026.02.11 KT&G CO LTD
  • EP4691288A1 patent drawingFigure 1
  • EP4691288A1 patent drawingFigure 2
  • EP4691288A1 patent drawingFigure 3~4

AI summary

A cartridge, according to an embodiment of the present invention, comprises: a container part that accommodates a liquid composition that generates aerosol when heated; and a water-repellent coating layer formed on the inner surface of the container part, wherein the coating layer may have a plurality of micro-scale protrusions protruding in the inward direction of the container part.