Multi-Spectrum Precious Metal Marking for Anti-Duplication Tracking

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Solution Overview

Problem

Existing security inks for precious metals like gold and silver are prone to duplication due to single emission-based tags and lack stability and toxicity, while existing methods fail to effectively adhere to gold surfaces without deformation.

Innovation Solution

A marking method using graphene and carbon quantum dots embedded in epoxy resin with fluorescein, allowing multi-level tracking and emission in different spectra, adhering to gold surfaces through epoxy resin bonding, and minimizing imitation risk.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If luminescent materials with downshifting and upconversion are used to increase security parameters, then the probability of decoding and duplication decreases, but the materials become less stable and highly toxic

Engineering Contradiction:
Improvesecurity against duplicationVSAvoidtoxicity and stability
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the material parameters by replacing traditional luminescent materials with quantum dots that have similar or enhanced luminescence properties but superior stability and reduced toxicity. The quantum dots maintain the multi-spectrum emission capability while eliminating the harmful effects of conventional materials.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material structures where quantum dots are embedded in a polymer matrix or combined with specific ligands and surfactants. This composite approach enhances the stability, reduces toxicity, and maintains the luminescence properties of the quantum dots for secure marking applications.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If conventional coating materials are applied to gold surfaces, then the marking can be applied, but the materials do not adhere due to gold's inertness

Engineering Contradiction:
Improvemarking applicationVSAvoidadhesion to gold surface
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces intermediary substances such as polymer binders, surfactants, or surface treatment agents that mediate between the inert gold surface and the coating materials. These intermediaries provide adhesion promotion without requiring deformation of the gold surface, enabling reliable marking application.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the surface parameters of gold through chemical treatment, plasma treatment, or application of adhesion promoters that modify the surface energy and reactivity of gold. This enables conventional coating materials to adhere to gold surfaces without mechanical deformation while maintaining the metal's inherent properties.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If single emission-based tags are used for tracking, then the system is simple, but the tags are prone to duplication

Engineering Contradiction:
Improvetracking system simplicityVSAvoidanti-duplication capability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the luminescence emission into multiple distinct spectral components or layers, each carrying specific identification information. This multi-layered or multi-spectral segmentation creates a complex authentication signature that is difficult to duplicate while maintaining systematic organization for verification.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from single-dimension (single emission wavelength) tagging to multi-dimensional tagging by utilizing multiple emission wavelengths, time-resolved luminescence, or polarization states. This dimensional expansion creates a richer information space for authentication that significantly increases security against duplication.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 method provides stable, non-toxic, and resistant multi-level tracking on gold surfaces with diverse emissions, preventing duplication and maintaining surface integrity.

Implementation Method 1

luminescent materials that absorb a high-energy photon and emit a low-energy photon, technically called as 'downshifting'

Methodology Applied
Scientific EffectDownshifting: Photoluminescence

Implementation Method 2

luminescent ink with the excitation luminescence properties as 'downshifting' and 'upconversion'

Methodology Applied
Scientific EffectUpconversion: Photoluminescence

Implementation Method 3

epoxy resin with graphene and carbon quantum dots and fluorescein

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP4377416B1Marking method screened in different spectrum
Publication Date: 2026.04.01 NANOGRAFI NANO TEKNOLOJI ANONIM SIRKETI
  • EP4377416B1 patent drawingFigure 1
  • EP4377416B1 patent drawingFigure 2
  • EP4377416B1 patent drawingFigure 3

AI summary

The present invention is a marking method (1) to be displayed in different spectra without the luster of the metal being affected in harsh conditions and applied to surfaces of precious metals for security applications. Together with the process, this marking method (1) enables labeling in more than one layer/level and wavelengths at different spectra. Moreover, the present invention is a marking method (1) that does not lose its chemical and physical resistance and property if the structure of the substance is exposed to physicochemical conditions.